Technical Field
[0001] The present invention relates to multi-phase detergent tablets.
Background
[0002] Detergent compositions in tablet form are known in the art. It is understood that
detergent compositions in tablet form hold several advantages over detergent compositions
in particulate form, such as ease of dosing, handling, transportation and storage.
[0003] Detergent tablets are most commonly prepared by pre-mixing components of a detergent
composition and forming the pre-mixed detergent components into a tablet using any
suitable equipment, preferably a tablet press. Tablets are typically formed by compression
of the components of the detergent composition so that the tablets produced are sufficiently
robust to be able to withstand handling and transportation without sustaining damage.
In addition to being robust, tablets must also dissolve sufficiently fast so that
the detergent components are released into the wash water as soon as possible at the
beginning of the wash cycle.
[0004] However, a dichotomy exists in that as compression force is increased, the rate of
dissolution of the tablets is slower. The present invention therefore seeks to find
a balance between tablet robustness and tablet dissolution.
[0005] Solutions to this problem, as seen in the prior art, have included compressing the
tablets with low compression pressure. However tablets made in this way, although
having a fast relative dissolution rate, tend to crumble, becoming damaged and unacceptable
to the consumer. Other solutions have included preparing tablets using a high relative
compression pressure, in order to achieve the required level of robustness, and comprising
a dissolution aid, such as an effervescent agent.
[0006] Multi-phase detergent tablets described in the prior art are prepared by compressing
a first composition in a tablet press to form a substantially planar first layer.
A further detergent composition is then delivered to the tablet press on top of the
first layer. This second composition is then compressed to form another substantially
planar second layer. Thus the first layer is generally subjected to more than one
compression as it is also compressed during the compression of the second composition.
Typically the first and second compression forces are in the same order of magnitude.
The Applicant has found that where this is the case, because the compression force
must be sufficient to bind the first and second compositions together, the force used
in both the first and second compression steps must be in the range of from about
4,000 to about 20,000 kg (assuming a tablet cross-section of about 10 cm
2). A consequence of this is a slower rate of tablet dissolution. Other multi-phase
tablets exhibiting differential dissolution are prepared such that the second layer
is compressed at a lower force than the first layer. However, although the dissolution
rate of the second layer is improved, the second layer is soft in comparison to the
first layer and is therefore vulnerable to damage caused by handling and transportation.
[0007] EP-B-0,055,100 describes a lavatory block formed by combining a slow dissolving shaped
body with a tablet. The lavatory block is designed to be placed in the cistern of
a lavatory and dissolves over a period of days, preferably weeks. As a means of slowing
the rate of dissolution of the lavatory block, the document teaches admixing one or
more solubility control agents. Examples of such solubility control agents are paradichlorobenzene,
waxes, long chain fatty acids and alcohols and esters thereof and fatty alkylamides.
Detergent tablets for use in laundry or automatic dishwashing must substantially dissolve
within one cycle of the washing or dishwashing machine, i.e. within 15 to 120 minutes.
Summary of the Invention
[0008] According to a first aspect of the invention, there is provided a multi-phase detergent
tablet for use in a washing machine, the tablet comprising:
a) a first phase in the form of a shaped body having at least one mould therein; and
b) a second phase in the form of a particulate solid compressed within said mould.
[0009] In preferred embodiments, the first phase is a compressed shaped body prepared at
an applied compression pressure of at least about 40 kg/ cm
2, preferably at least about 250 kg/ cm
2, more preferably at least about 350 kg/cm
2 (3.43 kN/cm
2), even more preferably from about 400 to about 2000, and especially from about 600
to about 1200 kg/cm
2 (compression pressure herein is the applied force divided by the cross-sectional
area of the tablet in a plane transverse to the applied force - in effect, the transverse
cross-sectional area of the die of the rotary press). It is also preferred that the
particulate solid of the second phase (which terminology is intended to include the
possibility of multiple 'second' phases, sometimes referred to herein as 'optional
subsequent phases') be compressed into said mould at an applied compression pressure
less than that applied to the first phase and preferably at a compression pressure
of less than about 350 kg/cm
2, preferably in the range from about 40 kg/cm
2 to about 300 kg/cm
2 and more preferably from about 70 to about 270 kg/cm
2, such tablets being preferred herein from the viewpoint of providing optimum tablet
integrity and strength (measured for example by the Child Bite Strength [CBS] test)
and product dissolution characteristics. The tablets of the invention preferably have
a CBS of at least about 6kg, preferably greater than about 8kg, more preferably greater
than about 10kg, especially greater than about 12kg, and more especially greater than
about 14kg, CBS being measured per the US Consumer Product Safety Commission Test
Specification. Also, the compression pressures applied to the first and second phases
will generally be in a ratio of at least about 1.2:1, preferably at least about 2:1,
more preferably at least about 4:1.
[0010] Thus, according to a further aspect of the invention, there is provided a multi-phase
detergent tablet for use in a washing machine, the tablet comprising:
a) a first phase in the form of a compressed shaped body having at least one mould
therein, the shaped body being prepared at a compression pressure of at least about
350 kg/cm2; and
b) a second phase in the form of a particulate solid compressed within said mould,
the second phase being compressed at a pressure of less than about 350 kg/cm2.
[0011] In other preferred embodiments, the second phase is in the form of a compressed or
shaped body adhesively contained, for example by physical or chemical adhesion, within
the at least one mould of the first body. It is also preferred that the first and
second phases are in a relatively high weight ratio to one another, for example at
least about 6:1, preferably at least about 10:1; also that the tablet composition
contain one or more detergent actives (for example enzymes, bleaches, bleach activators,
bleach catalysts, surfactants, chelating agents etc) which is predominantly concentrated
in the second phase, for example, at least about 50%, preferably at least about 60%,
especially about 80% by weight of the active (based on the total weight of the active
in tablet) is in the second phase of the tablet. Again, such compositions are optimum
for tablet strength, dissolution, cleaning, and pH regulation characteristics providing,
for example, tablet compositions capable of dissolving in the wash liquor so as to
deliver at least 50%, preferably at least 60%, and more preferably at least 80% by
weight of the detergent active to the wash liquor within 10, 5, 4 or even 3 minutes
of the start of the wash process.
[0012] Thus, according to another aspect of the invention, there is provided a multi-phase
detergent tablet for use in a washing machine, the tablet comprising:
a) a first phase in the form of a shaped body having at least one mould therein, and
b) a second phase in the form of a particulate solid compressed within said mould,
and wherein the tablet comprises at least one detergent active and is formulated such
that at least 50%, preferably at least 60%, more preferably at least 80% by weight
of the detergent active is delivered to the wash within the first 10 minutes, preferably
within the first 5 minutes, and more preferably within the first 3 minutes of the
wash process.
[0013] An additional benefit of the invention is the ability to achieve differential dissolution
of the phases, such that one phase of the tablet will dissolve significantly before
another phase, and may even dissolve essentially completely before the other phase
has dissolved. This is particularly valuable for the differential delivery of detergent
actives.
[0014] Thus, according to another aspect of the invention, there is provided a multi-phase
detergent tablet comprising:
a) a first phase in the form of a shaped body having at least one mould therein; and
b) a second phase in the form of a compressed body adhesively contained within said
mould, and wherein the tablet composition comprises one or more detergent actives
which is predominantly concentrated in the second phase, and wherein the second phase
additionally comprises a disrupting agent.
[0015] According to a further aspect of the invention there is provided a multi-phase detergent
tablet comprising:
a) a first phase in the form of a shaped body having at least one mould therein; and
b) a second phase in the form of a compressed body adhesively contained within said
mould, wherein the tablet composition comprises one or more detergent actives which
is predominantly concentrated in the second phase, and wherein the second phase additionally
comprises a binder.
[0016] Suitably, the one or more detergent actives are selected from enzymes, bleaches,
bleach activators, bleach catalysts, surfactants, chelating agents, crystal growth
inhibitors and mixtures thereof, the enzyme actives being particularly preferred for
boosting cleaning performance during the very initial cool-water stage of the washing
or cleaning operation. Highly preferred for use herein, therefore, are enzyme detergent
actives and especially enzymes and enzyme mixtures comprising one or more enzymes
having enhanced or optimum activity in the temperature range from 25 °C to 55°C and
at a pH value in the range of 8 to 10 (e.g. Natalase).
[0017] Thus, according to a yet another aspect of the invention, there is provided a multi-phase
detergent tablet comprising:
a) a first phase in the form of a shaped body having at least one mould therein; and
b) a second phase in the form of a compressed body adhesively contained within said
mould, and wherein the second phase additionally comprises an enzyme.
Detailed Description of the Invention
[0018] It is an object of the present invention to provide a detergent tablet that is not
only sufficiently robust to withstand handling and transportation, but also at least
a significant portion of which dissolves rapidly in the wash water providing rapid
delivery of detergent active. It is preferred that at least one phase of the tablet
dissolves in the wash water within the first ten minutes, preferably five minutes,
more preferably four minutes of the wash cycle of an automatic dishwashing or laundry
washing machine. Preferably the washing machine is either an automatic dishwashing
or laundry washing machine. The time within which the multi-phase tablet or a phase
thereof or a detergent active component dissolves is determined according to DIN 44990
using a dishwashing machine available from Bosch on the normal 65°C washing program
with water hardness at 18°H using a minimum of six replicates or a sufficient number
to ensure reproducibility.
[0019] The multi-phase detergent tablet of the present invention comprises a first phase,
a second and optionally subsequent phases. The first phase is in the form of a shaped
body of detergent composition comprising one or more detergent components as described
below. Preferred detergent components include, builder, bleach, enzymes and surfactant.
The components of the detergent composition are mixed together by, for example admixing
dry components or spraying-on liquid components. The components are then formed into
a first phase using any suitable equipment, but preferably by compression, for example
in a tablet press. Alternatively, the first phase can be prepared by extrusion, casting,
etc. The first phase can take a variety of geometric shapes such as spheres, cubes,
etc but preferred embodiments have a generally axially-symmetric form with a generally
round, square or rectangular cross-section.
[0020] The first phase is prepared such that it comprises at least one mould in the surface
of the shaped body. The mould or moulds can also vary in size and shape and in their
location, orientation and topology relative to the first phase. For example, the mould
or moulds can be generally circular, square or oval in cross-section; they can form
an internally-closed cavity or recess in the surface of the shaped body, or they can
extend between unconnected regions of the body surface (for example axially-opposed
facing surfaces) to form one or more topological 'holes' in the shaped body; and they
can be axially or otherwise symmetrically-disposed relative to the first phase or
they can be asymmetrically disposed. In a preferred embodiment the mould is created
using a specially designed tablet press wherein the surface of the punch that contacts
the detergent composition is shaped such that when it contacts and presses the detergent
composition it presses a mould, or multiple moulds into the first phase of the multi-phase
detergent tablet. Preferably, the mould will have an inwardly concave or generally
concave surface to provide improved adhesion to the second phase. Alternatively, the
mould can be created by compressing a preformed body of detergent composition disposed
annularly around a central dye, thereby forming a shaped body having a mould in the
form of a cavity extending axially between opposing surfaces of the body.
[0021] The tablets of the invention also include one or more additional phases prepared
from a composition or compositions which comprise one or more detergent components
as described below. At least one phase (herein referred to as a second phase) preferably
takes the form of a particulate solid (which term encompasses powders, granules, agglomerates,
and other particulate solids including mixtures thereof with liquid binders, meltable
solids, spray-ons, etc) compressed into/within the one or more moulds of the first
phase of the detergent tablet such that the second phase itself takes the form of
a shaped body. Optional further phases include one or more compositions in the form
a separate layer or layers. Preferred detergent components include builders, colourants,
binders, surfactants, disrupting agents and enzymes, in particular amylase and protease
enzymes. In another preferred aspect of the present invention the second and optionally
subsequent phases comprise a disrupting agent that may be selected from either a disintegrating
agent or an effervescent agent. Suitable disintegrating agents include agents that
swell on contact with water or facilitate water influx and/or efflux by forming channels
in the detergent tablet. Any known disintegrating or effervescing agent suitable for
use in laundry or dishwashing applications is envisaged for use herein. Suitable disintegrating
agent include starches (such as natural, modified, and pregelatinized starches, eg
those derived from corn, rice and potato starch), starch derivatives such as U-Sperse
(tradename), Primojel (tradename) and Explotab (tradename), celluloses, microcrystalline
celluloses and cellulose derivatives such as Arbocel (tradename) and Vivapur (tradename)
both available from Rettenmaier, Nymcel (tradename) available from Metsa-serla, Avicel
(tradename), Lattice NT (tradename) and Hanfloc (tradename), alginates, acetate trihydrate,
burkeite, monohydrated carbonate formula Na
2CO
3.H
2O, hydrated STPP with a phase I content of at least about 40% , carboxymethylcellulose
(CMC), CMC-based polymers, sodium acetate, aluminium oxide. Suitable effervescing
agents are those that produce a gas on contact with water. Suitable effervesing agents
may be oxygen, nitrogen dioxide or carbon dioxide evolving species. Examples of preferred
effervescent agents may be selected from the group consisting of perborate, percarbonate,
carbonate, bicarbonate in combination with carboxylic or other acids such as citric,
sulphamic, malic or maleic acid.
[0022] The components of the detergent composition are mixed together by for example admixing
dry components and admixing or spraying-on liquid components. The components of the
second and optionally subsequent phases are then fed into and retained within the
mould provided by the first phase.
[0023] The preferred embodiment of the present invention comprises two phases; a first and
a second phase. The first phase will normally comprise one mould and the second phase
will normally consist of a single detergent active composition. However, it is envisaged
that the first phase may comprise more than one mould and the second phase may be
prepared from more than one detergent active composition. Furthermore, it is also
envisaged that the second phase may comprise more than one detergent active composition
contained within one mould. It is also envisaged that several detergent active compositions
are contained in separate moulds. In this way potentially chemically sensitive detergent
components can be separated in order to avoid any loss in performance caused by components
reacting together and potentially becoming inactive or exhausted.
[0024] In a preferred aspect of the present invention the first, second and/or optionally
subsequent phases may comprise a binder. Where present the binder is selected from
the group consisting of organic polymers, for example polyethylene and/or polypropylene
glycols, especially those of molecular weight 4000, 6000 and 9000, paraffins, polyvinyl
pyrolindone (PVP), especially PVP of molecular weight 90 000, polyacrylates, sugars
and sugar derivatives, starch and starch derivatives, for example hydroxy propyl methyl
cellulose (HPMC) and carboxy methyl cellulose (CMC); and inorganic polymers, such
as hexametaphosphate. The binder is valuable both for tablet integrity and to help
achieve differential dissolution of the first and second phases as described below.
[0025] In a preferred aspect of the present invention the first phase weighs greater than
about 3g, preferably greater than about 4g, more preferably greater than about 5g.
More preferably the first phase weighs from about 10g to about 30g. even more preferably
from about 15g to about 25g and most preferably from about 18g to about 24g. The second
and optionally subsequent phases weigh less than 4g. More preferably the second and/or
optionally subsequent phases weigh between about 0.1g and about 3.5g, preferably between
about 1g and about 3.5g, most preferably from about 1.3g to about 2.5g.
[0026] In another embodiment of the present invention, a barrier layer comprising a barrier
layer composition is located between the first and second phase and/or optionally
subsequent phases or indeed between the second and optionally subsequent phases. The
barrier layer composition comprises at least one binder selected from the group as
described above. The advantage of the presence of a barrier layer is to prevent or
reduce migration of components from one phase to another phase, for example from the
first phase into the second and/or optionally subsequent phases and vice versa.
[0027] The components of the second and optionally subsequent phases are preferably compressed
at a very low compression force relative to compression force normally used to prepare
tablets. Thus an advantage of the present invention is that because a low compression
force is used heat, force or chemically sensitive detergent components can be incorporated
into the detergent tablet without sustaining the consequential loss in performance
usually encountered when incorporating such components into tablets. Alternatively,
the second phase or phases can be compressed at the same or higher compression force
than the first phase in order to achieve differential dissolution of the phases as
described below.
[0028] A further advantage of the present invention is the improved protection of the second
phase against damage caused by for example handling and transportation. As described
above multi-phase detergent tablets have been prepared where the second layer is compressed
at a lower compression force than the first layer. However although improving dissolution
rate, the second layer of these tablets becomes vulnerable to damage, tending to crumble
or chip on contact. The lightly compressed phase(s) of the detergent tablets of the
present invention however are protected within the mould provided by the first phase
of the detergent tablet.
[0029] Yet another advantage of the present invention is the ability to prepare a multi-phase
detergent tablet wherein one phase can be designed to dissolve, preferably significantly
before another phase. In the present invention it is preferred that the second and
optionally subsequent phase(s) dissolves before the first phase. According to the
preferred weight ranges described above, it preferable that the first phase dissolves
in from 5 to 20 minutes, more preferably from 10 to 15 minutes and the second and/or
optionally subsequent phases dissolve in less than 5 minutes, more preferably less
than 4.5 minutes, most preferably less than 4 minutes. Alternatively, the second phase
can dissolve after the first or other phases, for example, where it is desired to
deliver cleaning or rinsing benefits towards the end of the washing operation. The
time in which the first, second and/or optionally subsequent phase dissolve are independent
from each other. Thus in a particularly preferred aspect of the present invention
differential dissolution of the phases is achieved. A particular benefit of being
able to achieve differential dissolution of the multi-phase detergent tablet is that
a component that is chemically inactivated by the presence of another component can
be separated into a different phase. In this case the component that is inactivated
is preferably located in the second and optionally subsequent phase(s).
[0030] Yet another advantage of the present invention is the improved adherence between
the phases of the multi-phase tablet. It is believed that the improved adherence is
achieved by reducing exposure of the second phase in comparison to multi-phase tablets
known in the art, resulting in the tablets of the present invention being less susceptible
to fracture along the line of contact between the phases.
Process
[0031] The multi-phase detergent tablets are prepared using any suitable tabletting equipment,
e.g., a Courtoy R253. Preferably the tablets are prepared by compression in a tablet
press capable of preparing a tablet comprising a mould. In a particularly preferred
embodiment of the present invention the first phase is prepared using a specially
designed tablet press following the procedure described below. The punch(es) of this
tablet press are modified so that the surface of the punch that contacts the detergent
composition has a convex surface.
[0032] A first detergent composition is delivered into the die of the tablet press and the
punch is lowered to contact and then compress the detergent composition to form a
first phase. The first detergent composition is compressed using an applied pressure
generally of at least about 250 kg/cm
2, preferably between about 350 and about 2000 kg/cm
2, more preferably about 500 to about 1500 kg/cm
2, most preferably about 600 to about 1200 kg/cm
2. The punch is then elevated, exposing the first phase containing a mould. A second
and optionally subsequent detergent composition(s) is then delivered into the mould.
The specially designed tablet press punch is then lowered a second time to lightly
compress the second and optionally subsequent detergent composition(s) to form the
second and optionally subsequent phase(s). In another embodiment of the present invention
where an optionally subsequent phase is present the optionally subsequent phase is
prepared in an optionally subsequent compression step substantially similar to the
second compression step described above. The second and optionally subsequent detergent
composition(s) is compressed at a pressure of preferably less than about 350 kg/cm
2, more preferably from about 40 to about 300 kg/cm
2, most preferably from about 70 to about 270 kg/cm
2. After compression of the second detergent composition, the punch is elevated a second
time and the multi-phase detergent tablet is ejected from the tablet press.
Detergent Components
[0033] The first and second and or optionally subsequent phases of the multi-phase detergent
tablet described herein are prepared by compression of one or more compositions comprising
detergent active components. Suitably, the compositions used in any of these phases
may include a variety of different detergent components including builder compounds,
surfactants, enzymes, bleaching agents, alkalinity sources, colourants, perfume, lime
soap dispersants, organic polymeric compounds including polymeric dye transfer inhibiting
agents, crystal growth inhibitors, heavy metal ion sequestrants, metal ion salts,
enzyme stabilisers, corrosion inhibitors, suds suppressers, solvents, fabric softening
agents, optical brighteners and hydrotropes.
[0034] Highly preferred detergent components of the first phase include a builder compound,
a surfactant, an enzyme and a bleaching agent. Highly preferred detergent components
of the second phase include builder, enzymes, crystal growth inhibitors and disrupting
agents and/or binders
Builder compound
[0035] The tablets of the present invention preferably contain a builder compound, typically
present at a level of from 1% to 80% by weight, preferably from 10% to 70% by weight,
most preferably from 20% to 60% by weight of the composition of active detergent components.
Water-soluble builder compound
[0036] Suitable water-soluble builder compounds include the water soluble monomeric polycarboxylates,
or their acid forms, homo or copolymeric polycarboxylic acids or their salts in which
the polycarboxylic acid comprises at least two carboxylic radicals separated from
each other by not more that two carbon atoms, carbonates, bicarbonates, borates, phosphates,
and mixtures of any of the foregoing.
[0037] The carboxylate or polycarboxylate builder can be monomeric or oligomeric in type
although monomeric polycarboxylates are generally preferred for reasons of cost and
performance.
[0038] Suitable carboxylates containing one carboxy group include the water soluble salts
of lactic acid, glycolic acid and ether derivatives thereof. Polycarboxylates containing
two carboxy groups include the water-soluble salts of succinic acid, malonic acid,
(ethylenedioxy) diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic
acid and fumaric acid, as well as the ether carboxylates and the sulfinyl carboxylates.
Polycarboxylates containing three carboxy groups include, in particular, water-soluble
citrates, aconitrates and citraconates as well as succinate derivatives such as the
carboxymethyloxysuccinates described in British Patent No. 1,379,241, lactoxysuccinates
described in British Patent No. 1,389,732, and aminosuccinates described in Netherlands
Application 7205873, and the oxypolycarboxylate materials such as 2-oxa-1,1,3-propane
tricarboxylates described in British Patent No. 1,387,447.
[0039] Polycarboxylates containing four carboxy groups include oxydisuccinates disclosed
in British Patent No. 1,261,829, 1,1,2,2-ethane tetracarboxylates, 1,1,3,3-propane
tetracarboxylates and 1,1,2,3-propane tetracarboxylates. Polycarboxylates containing
sulfo substituents include the sulfosuccinate derivatives disclosed in British Patent
Nos. 1,398,421 and 1,398,422 and in U.S. Patent No. 3,936,448, and the sulfonated
pyrolysed citrates described in British Patent No. 1,439,000.
[0040] Alicyclic and heterocyclic polycarboxylates include cyclopentane-cis,cis,cis-tetracarboxylates,
cyclopentadienide pentacarboxylates, 2,3,4,5-tetrahydrofuran- cis, cis, cis-tetracarboxylates,
2,5-tetrahydrofuran - cis - dicarboxylates, 2,2,5,5-tetrahydrofuran - tetracarboxylates,
1,2,3,4,5,6-hexane - hexacarboxylates and carboxymethyl derivatives of polyhydric
alcohols such as sorbitol, mannitol and xylitol. Aromatic polycarboxylates include
mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed in British
Patent No. 1,425,343.
[0041] Of the above, the preferred polycarboxylates are hydroxycarboxylates containing up
to three carboxy groups per molecule, more particularly citrates.
[0042] The parent acids of the monomeric or oligomeric polycarboxylate chelating agents
or mixtures thereof with their salts, e.g. citric acid or citrate/citric acid mixtures
are also contemplated as useful builder components.
[0043] Borate builders, as well as builders containing borate-forming materials that can
produce borate under detergent storage or wash conditions can also be used but are
not preferred at wash conditions less that 50°C, especially less than 40°C.
[0044] Examples of carbonate builders are the alkaline earth and alkali metal carbonates,
including sodium carbonate and sesqui-carbonate and mixtures thereof with ultra-fine
calcium carbonate as disclosed in German Patent Application No. 2,321,001 published
on November 15, 1973.
[0045] Highly preferred builder compounds for use in the present invention are water-soluble
phosphate builders. Specific examples of water-soluble phosphate builders are the
alkali metal tripolyphosphates, sodium, potassium and ammonium pyrophosphate, sodium
and potassium and ammonium pyrophosphate, sodium and potassium orthophosphate, sodium
polymeta/phosphate in which the degree of polymerisation ranges from 6 to 21, and
salts of phytic acid.
[0046] Specific examples of water-soluble phosphate builders are the alkali metal tripolyphosphates,
sodium, potassium and ammonium pyrophosphate, sodium and potassium and ammonium pyrophosphate,
sodium and potassium orthophosphate, sodium polymeta/phosphate in which the degree
of polymerization ranges from 6 to 21, and salts of phytic acid.
Partially soluble or insoluble builder compound
[0047] The tablets of the present invention may contain a partially soluble or insoluble
builder compound. Partially soluble and insoluble builder compounds are particularly
suitable for use in tablets prepared for use in laundry cleaning methods. Examples
of partially water soluble builders include the crystalline layered silicates as disclosed
for example, in EP-A-0164514, DE-A-3417649 and DE-A-3742043. Preferred are the crystalline
layered sodium silicates of general formula
NaMSi
xO
2+1 .yH
2O
wherein M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from
0 to 20. Crystalline layered sodium silicates of this type preferably have a two dimensional
'sheet' structure, such as the so called δ-layered structure, as described in EP 0
164514 and EP 0 293640. Methods for preparation of crystalline layered silicates of
this type are disclosed in DE-A-3417649 and DE-A-3742043. For the purpose of the present
invention, x in the general formula above has a value of 2,3 or 4 and is preferably
2.
[0048] The most preferred crystalline layered sodium silicate compound has the formula δ-Na
2Si
2O
5, known as NaSKS-6 (trade name), available from Hoechst AG.
[0049] The crystalline layered sodium silicate material is preferably present in granular
detergent compositions as a particulate in intimate admixture with a solid, water-soluble
ionisable material as described in PCT Patent Application No. WO92/18594.
[0050] The solid, water-soluble ionisable material is selected from organic acids, organic
and inorganic acid salts and mixtures thereof, with citric acid being preferred.
[0051] Examples of largely water insoluble builders include the sodium aluminosilicates.
Suitable aluminosilicates include the aluminosilicate zeolites having the unit cell
formula Na
z[(AlO
2)
z(SiO
2)y]. xH
2O wherein z and y are at least 6; the molar ratio of z to y is from 1.0 to 0.5 and
x is at least 5, preferably from 7.5 to 276, more preferably from 10 to 264. The aluminosilicate
material are in hydrated form and are preferably crystalline, containing from 10%
to 28%, more preferably from 18% to 22% water in bound form.
[0052] The aluminosilicate zeolites can be naturally occurring materials, but are preferably
synthetically derived. Synthetic crystalline aluminosilicate ion exchange materials
are available under the designations Zeolite A, Zeolite B, Zeolite P, Zeolite X, Zeolite
HS and mixtures thereof.
[0053] A preferred method of synthesizing aluminosilicate zeolites is that described by
Schoeman et al (published in Zeolite (1994) 14(2), 110-116), in which the author describes
a method of preparing colloidal aluminosilicate zeolites. The colloidal aluminosilicate
zeolite particles should preferably be such that no more than 5% of the particles
are of size greater than 1µm in diameter and not more than 5% of particles are of
size less then 0.05 µm in diameter. Preferably the aluminosilicate zeolite particles
have an average particle size diameter of between 0.01µm and 1µm, more preferably
between 0.05 µm and 0.9 µm, most preferably between 0.1µm and 0.6 µm.
[0054] Zeolite A has the formula
Na
12[AlO
2)
12(SiO
2)
12]. xH
2O
wherein x is from 20 to 30, especially 27. Zeolite X has the formula Na
86 [(AlO
2)
86(SiO
2)
106]. 276 H
2O. Zeolite MAP, as disclosed in EP-B-384,070 is a preferred zeolite builder herein.
[0055] Preferred aluminosilicate zeolites are the colloidal aluminosilicate zeolites. When
employed as a component of a detergent composition colloidal aluminosilicate zeolites,
especially colloidal zeolite A, provide enhanced builder performance in terms of providing
improved stain removal. Enhanced builder performance is also seen in terms of reduced
fabric encrustation and improved fabric whiteness maintenance; problems believed to
be associated with poorly built detergent compositions.
[0056] A surprising finding is that mixed aluminosilicate zeolite detergent compositions
comprising colloidal zeolite A and colloidal zeolite Y provide equal calcium ion sequestration
performance versus an equal weight of commercially available zeolite A. Another surprising
finding is that mixed aluminosilicate zeolite detergent compositions, described above,
provide improved magnesium ion sequestration performance versus an equal weight of
commercially available zeolite A.
Surfactant
[0057] Surfactants are preferred detergent active components of the compositions described
herein. Suitable surfactants are selected from anionic, cationic, nonionic ampholytic
and zwitterionic surfactants and mixtures thereof Automatic dishwashing machine products
should be low foaming in character and thus the foaming of the surfactant system for
use in dishwashing methods must be suppressed or more preferably be low foaming, typically
nonionic in character. Sudsing caused by surfactant systems used in laundry cleaning
methods need not be suppressed to the same extent as is necessary for dishwashing.
The surfactant is typically present at a level of from 0.2% to 30% by weight, more
preferably from 0.5% to 10% by weight, most preferably from 1% to 5% by weight of
the composition of active detergent components.
[0058] A typical listing of anionic, nonionic, ampholytic and zwitterionic classes, and
species of these surfactants, is given in U.S.P. 3,929,678 issued to Laughlin and
Heuring on December, 30, 1975. A list of suitable cationic surfactants is given in
U.S.P. 4,259,217 issued to Murphy on March 31,1981. A listing of surfactants typically
included in automatic dishwashing detergent compositions is given for example, in
EP-A-0414 549 and PCT Applications No.s WO 93/08876 and WO 93/08874.
Nonionic surfactant
[0059] Essentially any nonionic surfactants useful for detersive purposes can be included
in the detergent tablet. Preferred, non-limiting classes of useful nonionic surfactants
are listed below.
Nonionic ethoxylated alcohol surfactant
[0060] The alkyl ethoxylate condensation products of aliphatic alcohols with from 1 to 25
moles of ethylene oxide are suitable for use herein. The alkyl chain of the aliphatic
alcohol can either be straight or branched, primary or secondary, and generally contains
from 6 to 22 carbon atoms. Particularly preferred are the condensation products of
alcohols having an alkyl group containing from 8 to 20 carbon atoms with from 2 to
10 moles of ethylene oxide per mole of alcohol.
End-capped alkyl alkoxylate surfactant
[0061] A suitable endcapped alkyl alkoxylate surfactant is the epoxy-capped poly(oxyalkylated)
alcohols represented by the formula:
R
1O[CH
2CH(CH
3)O]
x[CH
2CH
2O]
y[CH
2CH(OH)R
2] (I)
wherein R
1 is a linear or branched, aliphatic hydrocarbon radical having from 4 to 18 carbon
atoms; R
2 is a linear or branched aliphatic hydrocarbon radical having from 2 to 26 carbon
atoms; x is an integer having an average value of from 0.5 to 1.5, more preferably
1; and y is an integer having a value of at least 15, more preferably at least 20.
[0062] Preferably, the surfactant of formula I, at least 10 carbon atoms in the terminal
epoxide unit [CH
2CH(OH)R
2]. Suitable surfactants of formula I, according to the present invention, are Olin
Corporation's POLY-TERGENT® SLF-18B nonionic surfactants, as described, for example,
in WO 94/22800, published October 13, 1994 by Olin Corporation.
Ether-capped poly(oxyalkylated) alcohols
[0063] Preferred surfactants for use herein include ether-capped poly(oxyalkylated) alcohols
having the formula:
R
1O[CH
2CH(R
3)O]
x[CH
2]
kCH(OH)[CH
2]
jOR
2
wherein R
1 and R
2 are linear or branched, saturated or unsaturated, aliphatic or aromatic hydrocarbon
radicals having from 1 to 30 carbon atoms; R
3 is H, or a linear aliphatic hydrocarbon radical having from 1 to 4 carbon atoms;
x is an integer having an average value from 1 to 30, wherein when x is 2 or greater
R
3 may be the same or different and k and j are integers having an average value of
from 1 to 12, and more preferably 1 to 5.
[0064] R
1 and R
2 are preferably linear or branched, saturated or unsaturated, aliphatic or aromatic
hydrocarbon radicals having from 6 to 22 carbon atoms with 8 to 18 carbon atoms being
most preferred. H or a linear aliphatic hydrocarbon radical having from 1 to 2 carbon
atoms is most preferred for R
3. Preferably, x is an integer having an average value of from 1 to 20, more preferably
from 6 to 15.
[0065] As described above, when, in the preferred embodiments, and x is greater than 2,
R
3 may be the same or different. That is, R
3 may vary between any of the alklyeneoxy units as described above. For instance, if
x is 3, R
3 may be be selected to form ethlyeneoxy(EO) or propyleneoxy(PO) and may vary in order
of (EO)(PO)(EO), (EO)(EO)(PO); (EO)(EO)(EO); (PO)(EO)(PO); (PO)(PO)(EO) and (PO)(PO)(PO).
Of course, the integer three is chosen for example only and the variation may be much
larger with a higher integer value for x and include, for example, mulitple (EO) units
and a much small number of (PO) units.
[0066] Particularly preferred surfactants as described above include those that have a low
cloud point of less than 20°C. These low cloud point surfactants may then be employed
in conjunction with a high cloud point surfactant as described in detail below for
superior grease cleaning benefits.
[0067] Most preferred ether-capped poly(oxyalkylated) alcohol surfactants are those wherein
k is 1 and j is 1 so that the surfactants have the formula:
R
1O[CH
2CH(R
3)O]
xCH
2CH(OH)CH
2OR
2
where R
1, R
2 and R
3 are defined as above and x is an integer with an average value of from 1 to 30, preferably
from 1 to 20, and even more preferably from 6 to 18. Most preferred are surfactants
wherein R
1 and R
2 range from 9 to 14, R
3 is H forming ethyleneoxy and x ranges from 6 to 15.
[0068] The ether-capped poly(oxyalkylated) alcohol surfactants comprise three general components,
namely a linear or branched alcohol, an alkylene oxide and an alkyl ether end cap.
The alkyl ether end cap and the alcohol serve as a hydrophobic, oil-soluble portion
of the molecule while the alkylene oxide group forms the hydrophilic, water-soluble
portion of the molecule.
[0069] These surfactants exhibit significant improvements in spotting and filming characteristics
and removal of greasy soils, when used in conjunction with high cloud point surfactants,
relative to conventional surfactants.
[0070] Generally speaking, the ether-capped poly(oxyalkylene) alcohol surfactants of the
present invention may be produced by reacting an aliphatic alcohol with an epoxide
to form an ether which is then reacted with a base to form a second epoxide. The second
epoxide is then reacted with an alkoxylated alcohol to form the novel compounds of
the present invention. Examples of methods of preparing the ether-capped poly(oxyalkylated)
alcohol surfactants are described below:
Preparation of C12/14 alkyl glycidyl ether
[0071] A C
12/14 fatty alcohol (100.00 g, 0.515 mol.) and tin (IV) chloride (0.58 g, 2.23 mmol, available
from Aldrich) are combined in a 500 mL three-necked round-bottomed flask fitted with
a condenser, argon inlet, addition funnel, magnetic stirrer and internal temperature
probe. The mixture is heated to 60 °C. Epichlorhydrin (47.70 g, 0.515 mol, available
from Aldrich) is added dropwise so as to keep the temperature between 60-65 °C. After
stirring an additional hour at 60 °C, the mixture is cooled to room temperature. The
mixture is treated with a 50% solution of sodium hydroxide (61.80 g, 0.773 mol, 50%)
while being stirred mechanically. After addition is completed, the mixture is heated
to 90 °C for 1.5 h, cooled, and filtered with the aid of ethanol. The filtrate is
separated and the organic phase is washed with water (100 mL), dried over MgSO
4, filtered, and concentrated. Distillation of the oil at 100-120 °C (0.1 mm Hg) providing
the glycidyl ether as an oil.
Preparation of C12/14 alkyl-C9/11 ether capped alcohol surfactant
[0072] Neodol® 91-8 (20.60 g, 0.0393 mol ethoxylated alcohol available from the Shell chemical
Co.) and tin (IV) chloride (0.58 g, 2.23 mmol) are combined in a 250 mL three-necked
round-bottomed flask fitted with a condenser, argon inlet, addition tunnel, magnetic
stirrer and internal temperature probe. The mixture is heated to 60 ° C at which point
C
12/14 alkyl glycidyl ether (11.00 g, 0.0393 mol) is added dropwise over 15 min. After stirring
for 18 h at 60 °C, the mixture is cooled to room temperature and dissolved in an equal
portion of dichloromethane. The solution is passed through a 1 inch pad of silica
gel while eluting with dichloromethane. The filtrate is concentrated by rotary evaporation
and then stripped in a kugelrohr oven (100 °C, 0.5 mm Hg) to yield the surfactant
as an oil.
Nonionic ethoxylated/propoxylated fatty alcohol surfactant
[0073] The ethoxylated C
6-C
18 fatty alcohols and C
6-C
18 mixed ethoxylated/propoxylated fatty alcohols are suitable surfactants for use herein,
particularly where water soluble. Preferably the ethoxylated fatty alcohols are the
C
10-C
18 ethoxylated fatty alcohols with a degree of ethoxylation of from 3 to 50, most preferably
these are the C
12-C
18 ethoxylated fatty alcohols with a degree of ethoxylation from 3 to 40. Preferably
the mixed ethoxylated/propoxylated fatty alcohols have an alkyl chain length of from
10 to 18 carbon atoms, a degree of ethoxylation of from 3 to 30 and a degree of propoxylation
of from 1 to 10.
Nonionic EO/PO condensates with propylene glycol
[0074] The condensation products of ethylene oxide with a hydrophobic base formed by the
condensation of propylene oxide with propylene glycol are suitable for use herein.
The hydrophobic portion of these compounds preferably has a molecular weight of from
1500 to 1800 and exhibits water insolubility. Examples of compounds of this type include
certain of the commercially-available Pluronic™ surfactants, marketed by BASF.
Nonionic EO condensation products with propylene oxide/ethylene diamine adducts
[0075] The condensation products of ethylene oxide with the product resulting from the reaction
of propylene oxide and ethylenediamine are suitable for use herein. The hydrophobic
moiety of these products consists of the reaction product of ethylenediamine and excess
propylene oxide, and generally has a molecular weight of from 2500 to 3000. Examples
of this type of nonionic surfactant include certain of the commercially available
Tetronic™ compounds, marketed by BASF.
Mixed Nonionic Surfactant System
[0076] In a preferred embodiment of the present invention the detergent tablet comprises
a mixed nonionic surfactant system comprising at least one low cloud point nonionic
surfactant and at least one high cloud point nonionic surfactant.
[0077] "Cloud point", as used herein, is a well known property of nonionic surfactants which
is the result of the surfactant becoming less soluble with increasing temperature,
the temperature at which the appearance of a second phase is observable is referred
to as the "cloud point" (See Kirk Othmer's Encyclopedia of Chemical Technology, 3
rd Ed. Vol. 22, pp. 360-379).
[0078] As used herein, a "low cloud point" nonionic surfactant is defined as a nonionic
surfactant system ingredient having a cloud point of less than 30°C, preferably less
than 20°C, and most preferably less than 10°C. Typical low cloud point nonionic surfactants
include nonionic alkoxylated surfactants, especially ethoxylates derived from primary
alcohol, and polyoxypropylene/polyoxyethylene/polyoxypropylene (PO/EO/PO) reverse
block polymers. Also, such low cloud point nonionic surfactants include, for example,
ethoxylated-propoxylated alcohol (e.g., Olin Corporation's Poly-Tergent® SLF18), epoxy-capped
poly(oxyalkylated) alcohols (e.g., Olin Corporation's Poly-Tergent® SLF18B series
of nonionics, as described, for example, in WO 94/22800, published October 13, 1994
by Olin Corporation)and the ether-capped poly(oxyalkylated) alcohol surfactants.
[0079] Nonionic surfactants can optionally contain propylene oxide in an amount up to 15%
by weight. Other preferred nonionic surfactants can be prepared by the processes described
in U.S. Patent 4,223,163, issued September 16, 1980, Builloty, incorporated herein
by reference.
[0080] Low cloud point nonionic surfactants additionally comprise a polyoxyethylene, polyoxypropylene
block polymeric compound. Block polyoxyethylene-polyoxypropylene polymeric compounds
include those based on ethylene glycol, propylene glycol, glycerol, trimethylolpropane
and ethylenediamine as initiator reactive hydrogen compound. Certain of the block
polymer surfactant compounds designated PLURONIC®, REVERSED PLURONIC®, and TETRONIC®
by the BASF-Wyandotte Corp., Wyandotte, Michigan, are suitable in ADD compositions
of the invention. Preferred examples include REVERSED PLURONIC® 25R2 and TETRONIC®
702, Such surfactants are typically useful herein as low cloud point nonionic surfactants.
[0081] As used herein, a "high cloud point" nonionic surfactant is defined as a nonionic
surfactant system ingredient having a cloud point of greater than 40°C, preferably
greater than 50°C, and more preferably greater than 60°C. Preferably the nonionic
surfactant system comprises an ethoxylated surfactant derived from the reaction of
a monohydroxy alcohol or alkylphenol containing from 8 to 20 carbon atoms, with from
6 to 15 moles of ethylene oxide per mole of alcohol or alkyl phenol on an average
basis. Such high cloud point nonionic surfactants include, for example, Tergitol 15S9
(supplied by Union Carbide), Rhodasurf TMD 8.5 (supplied by Rhone Poulenc), and Neodol
91-8 (supplied by Shell).
[0082] It is also preferred for purposes of the present invention that the high cloud point
nonionic surfactant further have a hydrophile-lipophile balance ("HLB"; see Kirk Othmer
hereinbefore) value within the range of from 9 to 15, preferably 11 to 15. Such materials
include, for example, Tergitol 15S9 (supplied by Union Carbide), Rhodasurf TMD 8.5
(supplied by Rhone Poulenc), and Neodol 91-8 (supplied by Shell).
[0083] Another preferred high cloud point nonionic surfactant is derived from a straight
or preferably branched chain or secondary fatty alcohol containing from 6 to 20 carbon
atoms (C
6-C
20 alcohol), including secondary alcohols and branched chain primary alcohols. Preferably,
high cloud point nonionic surfactants are branched or secondary alcohol ethoxylates,
more preferably mixed C9/11 or C11/15 branched alcohol ethoxylates, condensed with
an average of from 6 to 15 moles, preferably from 6 to 12 moles, and most preferably
from 6 to 9 moles of ethylene oxide per mole of alcohol. Preferably the ethoxylated
nonionic surfactant so derived has a narrow ethoxylate distribution relative to the
average.
Anionic surfactant
[0084] Essentially any anionic surfactants useful for detersive purposes are suitable. These
can include salts (including, for example, sodium, potassium, ammonium, and substituted
ammonium salts such as mono-, di- and triethanolamine salts) of the anionic sulfate,
sulfonate, carboxylate and sarcosinate surfactants. Anionic sulfate surfactants are
preferred.
[0085] Other anionic surfactants include the isethionates such as the acyl isethionates,
N-acyl taurates, fatty acid amides of methyl tauride, alkyl succinates and sulfosuccinates,
monoesters of sulfosuccinate (especially saturated and unsaturated C
12-C
18 monoesters) diesters of sulfosuccinate (especially saturated and unsaturated C
6-C
14 diesters), N-acyl sarcosinates. Resin acids and hydrogenated resin acids are also
suitable, such as rosin, hydrogenated rosin, and resin acids and hydrogenated resin
acids present in or derived from tallow oil.
Anionic sulfate surfactant
[0086] Anionic sulfate surfactants suitable for use herein include the linear and branched
primary and secondary alkyl sulfates, alkyl ethoxysulfates, fatty oleoyl glycerol
sulfates, alkyl phenol ethylene oxide ether sulfates, the C
5-C
17 acyl-N-(C
1-C
4 alkyl) and -N-(C
1-C
2 hydroxyalkyl) glucamine sulfates, and sulfates of alkylpolysaccharides such as the
sulfates of alkylpolyglucoside (the nonionic nonsulfated compounds being described
herein).
[0087] Alkyl sulfate surfactants are preferably selected from the linear and branched primary
C
10-C
18 alkyl sulfates, more preferably the C
11-C
15 branched chain alkyl sulfates and the C
12-C
14 linear chain alkyl sulfates.
[0088] Alkyl ethoxysulfate surfactants are preferably selected from the group consisting
of the C
10-C
18 alkyl sulfates which have been ethoxylated with from 0.5 to 20 moles of ethylene
oxide per molecule. More preferably, the alkyl ethoxysulfate surfactant is a C
11-C
18, most preferably C
11-C
15 alkyl sulfate which has been ethoxylated with from 0.5 to 7, preferably from I to
5, moles of ethylene oxide per molecule.
[0089] A particularly preferred aspect of the invention employs mixtures of the preferred
alkyl sulfate and alkyl ethoxysulfate surfactants. Such mixtures have been disclosed
in PCT Patent Application No. WO 93/18124.
Anionic sulfonate surfactant
[0090] Anionic sulfonate surfactants suitable for use herein include the salts of C
5-C
20 linear alkylbenzene sulfonates, alkyl ester sulfonates, C
6-C
22 primary or secondary alkane sulfonates, C
6-C
24 olefin sulfonates, sulfonated polycarboxylic acids, alkyl glycerol sulfonates, fatty
acyl glycerol sulfonates, fatty oleyl glycerol sulfonates, and any mixtures thereof.
Anionic carboxylate surfactant
[0091] Suitable anionic carboxylate surfactants include the alkyl ethoxy carboxylates, the
alkyl polyethoxy polycarboxylate surfactants and the soaps ('alkyl carboxyls'), especially
certain secondary soaps as described herein.
[0092] Suitable alkyl ethoxy carboxylates include those with the formula RO(CH
2CH
20)
x CH
2C00
-M
+ wherein R is a C
6 to C
18 alkyl group, x ranges from O to 10, and the ethoxylate distribution is such that,
on a weight basis, the amount of material where x is 0 is less than 20 % and M is
a cation. Suitable alkyl polyethoxy polycarboxylate surfactants include those having
the formula RO-(CHR
1-CHR
2-O)-R
3 wherein R is a C
6 to C
18 alkyl group, x is from 1 to 25, R
1 and R
2 are selected from the group consisting of hydrogen, methyl acid radical, succinic
acid radical, hydroxysuccinic acid radical, and mixtures thereof, and R
3 is selected from the group consisting of hydrogen, substituted or unsubstituted hydrocarbon
having between 1 and 8 carbon atoms, and mixtures thereof.
[0093] Suitable soap surfactants include the secondary soap surfactants which contain a
carboxyl unit connected to a secondary carbon. Preferred secondary soap surfactants
for use herein are water-soluble members selected from the group consisting of the
water-soluble salts of 2-methyl-1-undecanoic acid, 2-ethyl-1-decanoic acid, 2-propyl-1-nonanoic
acid, 2-butyl-1-octanoic acid and 2-pentyl-1-heptanoic acid. Certain soaps may also
be included as suds suppressors.
Alkali metal sarcosinate surfactant
[0094] Other suitable anionic surfactants are the alkali metal sarcosinates of formula R-CON
(R
1) CH
2 COOM, wherein R is a C
5-C
17 linear or branched alkyl or alkenyl group, R
1 is a C
1-C
4 alkyl group and M is an alkali metal ion. Preferred examples are the myristyl and
oleoyl methyl sarcosinates in the form of their sodium salts.
Amphoteric surfactant
[0095] Suitable amphoteric surfactants for use herein include the amine oxide surfactants
and the alkyl amphocarboxylic acids.
[0096] Suitable amine oxides include those compounds having the formula R
3(OR
4)
xN
0(R
5)
2 wherein R
3 is selected from an alkyl, hydroxyalkyl, acylamidopropoyl and alkyl phenyl group,
or mixtures thereof, containing from 8 to 26 carbon atoms; R
4 is an alkylene or hydroxyalkylene group containing from 2 to 3 carbon atoms, or mixtures
thereof; x is from 0 to 5, preferably from 0 to 3; and each R
5 is an alkyl or hydroxyalkyl group containing from 1 to 3, or a polyethylene oxide
group containing from 1 to 3 ethylene oxide groups. Preferred are C
10-C
18 alkyl dimethylamine oxide, and C
10-18 acylamido alkyl dimethylamine oxide.
[0097] A suitable example of an alkyl aphodicarboxylic acid is Miranol(TM) C2M Conc. manufactured
by Miranol, Inc., Dayton, NJ.
Zwitterionic surfactant
[0098] Zwitterionic surfactants can also be incorporated into the detergent compositions
hereof. These surfactants can be broadly described as derivatives of secondary and
tertiary amines, derivatives of heterocyclic secondary and tertiary amines, or derivatives
of quaternary ammonium quaternary phosphonium or tertiary sulfonium compounds. Betaine
and sultaine surfactants are exemplary zwitterionic surfactants for use herein.
[0099] Suitable betaines are those compounds having the formula R(R')
2N
+R
2COO
- wherein R is a C
6-C
18 hydrocarbyl group, each R
1 is typically C
1-C
3 alkyl, and R
2 is a C
1-C
5 hydrocarbyl group. Preferred betaines are C
12-18 dimethyl-ammonio hexanoate and the C
10-18 acylamidopropane (or ethane) dimethyl (or diethyl) betaines. Complex betaine surfactants
are also suitable for use herein.
Cationic surfactants
[0100] Cationic ester surfactants used in this invention are preferably water dispersible
compound having surfactant properties comprising at least one ester (i.e. -COO-) linkage
and at least one cationically charged group. Other suitable cationic ester surfactants,
including choline ester surfactants, have for example been disclosed in US Patents
No.s 4228042, 4239660 and 4260529.
[0101] Suitable cationic surfactants include the quaternary ammonium surfactants selected
from mono C
6-C
16, preferably C
6-C
10 N-alkyl or alkenyl ammonium surfactants wherein the remaining N positions are substituted
by methyl, hydroxyethyl or hydroxypropyl groups.
Enzymes
[0102] Enzymes are preferred detergent components of the first phase and more particularly
the second and/or optionally further phases. Where present said enzymes are selected
from the group consisting of cellulases, hemicellulases, peroxidases, proteases, gluco-amylases,
amylases, xylanases, lipases, phospholipases, esterases, cutinases, pectinases, keratanases,
reductases, oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases,
pentosanases, malanases, β-glucanases, arabinosidases, hyaluronidase, chondroitinase,
laccase or mixtures thereof.
[0103] Preferred enzymes include protease, amylase, lipase, peroxidases, cutinase and/or
cellulase in conjunction with one or more plant cell wall degrading enzymes.
[0104] The cellulases usable in the present invention include both bacterial or fungal cellulase.
Preferably, they will have a pH optimum of between 5 and 12 and an activity above
50 CEVU (Cellulose Viscosity Unit). Suitable cellulases are disclosed in U.S. Patent
4,435,307, Barbesgoard et al, J61078384 and WO96/02653 which disclose fungal cellulases
produced respectively from Humicola insolens Trichoderma, Thielavia and Sporotrichum.
EP 739 982 describes cellulases isolated from novel Bacillus species. Suitable cellulases
are also disclosed in GB-A-2.075.028 ; GB-A-2.095.275; DE-OS-2.247.832 and WO95/26398.
[0105] Examples of such cellulases are cellulases produced by a strain of Humicola insolens
(Humicola grisea var. thermoidea), particularly the Humicola strain DSM 1800. Other
suitable cellulases are cellulases originated from Humicola insolens having a molecular
weight of 50KDa, an isoelectric point of 5.5 and containing 415 amino acids; and a
~43kD endoglucanase derived from Humicola insolens, DSM 1800, exhibiting cellulase
activity; a preferred endoglucanase component has the amino acid sequence disclosed
in PCT Patent Application No. WO 91/17243. Also suitable cellulases are the EGIII
cellulases from Trichoderma longibrachiatum described in WO94/21801, Genencor, published
September 29, 1994. Especially suitable cellulases are the cellulases having color
care benefits. Examples of such cellulases are cellulases described in European patent
application No. 91202879.2, filed November 6, 1991 (Novo). Carezyme and Celluzyme
(Novo Nordisk A/S) are especially useful. See also WO91/17244 and WO91/21801. Other
suitable cellulases for fabric care and/or cleaning properties are described in WO96/34092,
WO96/17994 and WO95/24471.
[0106] Said cellulases are normally incorporated in the detergent composition at levels
from 0.0001% to 2% of active enzyme by weight of the detergent composition.
[0107] Peroxidase enzymes are used in combination with oxygen sources, e.g. percarbonate,
perborate, persulfate, hydrogen peroxide, etc. They are used for "solution bleaching",
i.e. to prevent transfer of dyes or pigments removed from substrates during wash operations
to other substrates in the wash solution. Peroxidase enzymes are known in the art,
and include, for example, horseradish peroxidase, ligninase and haloperoxidase such
as chloro- and bromo-peroxidase. Peroxidase-containing detergent compositions are
disclosed, for example, in PCT International Application WO 89/099813, WO89/09813
and in European Patent application EP No. 91202882.6, filed on November 6, 1991 and
EP No. 96870013.8, filed February 20, 1996. Also suitable is the laccase enzyme.
[0108] Preferred enhancers are substitued phenthiazine and phenoxasine 10-Phenothiazinepropionicacid
(PPT), 10-ethylphenothiazine-4-carboxylic acid (EPC), 10-phenoxazinepropionic acid
(POP) and 10-methylphenoxazine (described in WO 94/12621) and substitued syringates
(C3-C5 substitued alkyl syringates) and phenols. Sodium percarbonate or perborate
are preferred sources of hydrogen peroxide.
[0109] Said cellulases and/or peroxidases are normally incorporated in the detergent composition
at levels from 0.0001% to 2% of active enzyme by weight of the detergent composition.
[0110] Other preferred enzymes that can be included in the detergent compositions of the
present invention include lipases. Suitable lipase enzymes for detergent usage include
those produced by microorganisms of the Pseudomonas group, such as Pseudomonas stutzeri
ATCC 19.154, as disclosed in British Patent 1,372,034. Suitable lipases include those
which show a positive immunological cross-reaction with the antibody of the lipase,
produced by the microorganism
Pseudomonas fluorescent IAM 1057. This lipase is available from Amano Pharmaceutical Co. Ltd., Nagoya, Japan,
under the trade name Lipase P "Amano," hereinafter referred to as "Amano-P". Other
suitable commercial lipases include Amano-CES, lipases ex
Chromobacter viscosum, e.g.
Chromobacter viscosum var. lipolyticum NRRLB 3673 from Toyo Jozo Co., Tagata, Japan;
Chromobacter viscosum lipases from U.S. Biochemical Corp., U.S.A. and Disoynth Co., The Netherlands, and
lipases ex
Pseudomonas gladioli. Especially suitable lipases are lipases such as M1 Lipase
R and Lipomax
R (Gist-Brocades) and LipolaseR and Lipolase Ultra
R(Novo) which have found to be very effective when used in combination with the compositions
of the present invention. Also suitables are the lipolytic enzymes described in EP
258 068, WO 92/05249 and WO 95/22615 by Novo Nordisk and in WO 94/03578, WO 95/35381
and WO 96/00292 by Unilever.
[0111] Also suitable are cutinases [EC 3.1.1.50] which can be considered as a special kind
of lipase, namely lipases which do not require interfacial activation. Addition of
cutinases to detergent compositions have been described in e.g. WO-A-88/09367 (Genencor);
WO 90/09446 (Plant Genetic System) and WO 94/14963 and WO 94/14964 (Unilever).
[0112] The lipases and/or cutinases are normally incorporated in the detergent composition
at levels from 0.0001% to 2% of active enzyme by weight of the detergent composition.
[0113] Suitable proteases are the subtilisins which are obtained from particular strains
of
B. subtilis and
B. licheniformis (subtilisin BPN and BPN'). One suitable protease is obtained from a strain of
Bacillus, having maximum activity throughout the pH range of 8-12, developed and sold as ESPERASE®
by Novo Industries A/S of Denmark, hereinafter "Novo". The preparation of this enzyme
and analogous enzymes is described in GB 1,243,784 to Novo. Other suitable proteases
include KANNASE®, ALCALASE®, DURAZYM® and SAVINASE® from Novo and MAXATASE®, MAXACAL®,
PROPERASE® and MAXAPEM® (protein engineered Maxacal) from Gist-Brocades. Proteolytic
enzymes also encompass modified bacterial serine proteases, such as those described
in European Patent Application Serial Number 87 303761.8, filed April 28, 1987 (particularly
pages 17, 24 and 98), and which is called herein "Protease B", and in European Patent
Application 199,404, Venegas, published October 29, 1986, which refers to a modified
bacterial serine protealytic enzyme which is called "Protease A" herein. Suitable
is what is called herein "Protease C", which is a variant of an alkaline serine protease
from
Bacillus in which lysine replaced arginine at position 27, tyrosine replaced valine at position
104, serine replaced asparagine at position 123, and alanine replaced threonine at
position 274. Protease C is described in EP 90915958:4, corresponding to WO 91/06637,
Published May 16, 1991. Genetically modified variants, particularly of Protease C,
are also included herein.
[0114] A preferred protease referred to as "Protease D" is a carbonyl hydrolase variant
having an amino acid sequence not found in nature, which is derived from a precursor
carbonyl hydrolase by substituting a different amino acid for a plurality of amino
acid residues at a position in said carbonyl hydrolase equivalent to position +76,
preferably also in combination with one or more amino acid residue positions equivalent
to those selected from the group consisting of +99, +101, +103, +104, +107, +123,
+27, +105, +109, +126, +128, +135, +156, +166, +195, +197, +204, +206, +210, +216,
+217, +218, +222, +260, +265, and/or +274 according to the numbering
of Bacillus amyloliquefaciens subtilisin, as described in WO95/10591 and in the patent application of C. Ghosh,
et al, "Bleaching Compositions Comprising Protease Enzymes" having US Serial No. 08/322,677,
filed October 13, 1994.
[0115] Also suitable for the present invention are proteases described in patent applications
EP 251 446 and WO 91/06637, protease BLAP® described in WO91/02792 and their variants
described in WO 95/23221.
[0116] See also a high pH protease from Bacillus sp. NCIMB 40338 described in WO 93/18140
A to Novo. Enzymatic detergents comprising protease, one or more other enzymes, and
a reversible protease inhibitor are described in WO 92/03529 A to Novo. When desired,
a protease having decreased adsorption and increased hydrolysis is available as described
in WO 95/07791 to Procter & Gamble. A recombinant trypsin-like protease for detergents
suitable herein is described in WO 94/25583 to Novo. Other suitable proteases are
described in EP 516 200 by Unilever.
[0117] Other preferred protease enzymes include protease enzymes which are a carbonyl hydrolase
variant having an amino acid sequence not found in nature, which is derived by replacement
of a plurality of amino acid residues of a precursor carbonyl hydrolase with different
amino acids, wherein said plurality of amino acid residues replaced in the precursor
enzyme correspond to position +210 in combination with one or more ofthe following
residues: +33, +62, +67, +76, +100, +101, +103, +104, +107, +128, +129, +130, +132,
+135, +156, +158, +164, +166, +167, +170, +209, +215, +217, +218 and +222, where the
numbered positions correspond to naturally-occurring subtilisin from
Bacillus amyloliquefaciens or to equivalent amino acid residues in other carbonyl hydrolases or subtilisins
(such as
Bacillus lentus subtilisin). Preferred enzymes of this type include those having position changes
+210, +76, +103, +104, +156, and +166.
[0118] The proteolytic enzymes are incorporated in the detergent compositions of the present
invention a level of from 0.0001% to 2%, preferably from 0.001% to 0.2%, more preferably
from 0.005% to 0.1% pure enzyme by weight of the composition.
[0119] Amylases (α and/or β) can be included for removal of carbohydrate-based stains. WO94/02597,
Novo Nordisk A/S published February 03, 1994, describes cleaning compositions which
incorporate mutant amylases. See also WO95/10603, Novo Nordisk A/S, published April
20, 1995. Other amylases known for use in cleaning compositions include both α- and
β-amylases. α-Amylases are known in the art and include those disclosed in US Pat.
no. 5,003,257; EP 252,666; WO/91/00353; FR 2,676,456; EP 285,123; EP 525,610; EP 368,341;
and British Patent specification no. 1,296,839 (Novo). Other suitable amylases are
stability-enhanced amylases described in WO94/18314, published August 18, 1994 and
WO96/05295, Genencor, published February 22, 1996 and amylase variants having additional
modification in the immediate parent available from Novo Nordisk A/S, disclosed in
WO 95/10603, published April 95. Also suitable are amylases described in EP 277 216,
WO95/26397 and WO96/23873 (all by Novo Nordisk).
[0120] Examples of commercial α-amylases products are Purafect Ox Am® from Genencor and
Termamyl®, Ban® ,Fungamyl® and Duramyl®, Natalase ® all available from Novo Nordisk
A/S Denmark. WO95/26397 describes other suitable amylases : α-amylases characterised
by having a specific activity at least 25% higher than the specific activity of Termamyl®
at a temperature range of 25°C to 55°C and at a pH value in the range of 8 to 10,
measured by the Phadebas® α-amylase activity assay. Suitable are variants of the above
enzymes, described in WO96/23873 (Novo Nordisk). Other amylolytic enzymes with improved
properties with respect to the activity level and the combination of thermostability
and a higher activity level are described in WO95/35382.
[0121] Preferred amylase enzymes include those described in WO95/26397 and in co-pending
application by Novo Nordisk PCT/DK96/00056.
[0122] The amylolytic enzymes are incorporated in the detergent compositions of the present
invention a level of from 0.0001% to 2%, preferably from 0.00018% to 0.06%, more preferably
from 0.00024% to 0.048% pure enzyme by weight of the composition
[0123] In a particularly preferred embodiment, detergent tablets of the present invention
comprise amylase enzymes, particularly those described in WO95/26397 and co-pending
application by Novo Nordisk PCT/DK96/00056 in combination with a complementary amylase.
[0124] By "complementary" it is meant the addition of one or more amylase suitable for detergency
purposes. Examples of complementary amylases (α and/or β) are described below. WO94/02597
and WO95/10603, Novo Nordisk A/S describe cleaning compositions which incorporate
mutant amylases. Other amylases known for use in cleaning compositions include both
α- and β-amylases, α-Amylases are known in the art and include those disclosed in
US Pat. no. 5,003,257; EP 252,666; WO/91/00353; FR 2,676,456; EP 285,123; EP 525,610;
EP 368,341; and British Patent specification no. 1,296,839 (Novo). Other suitable
amylases are stability-enhanced amylases described in WO94/18314, and WO96/05295,
Genencor and amylase variants having additional modification in the immediate parent
available from Novo Nordisk A/S, disclosed in WO 95/10603. Also suitable are amylases
described in EP 277 216 (Novo Nordisk). Examples of commercial α-amylases products
are Purafect Ox Am® from Genencor and Termamyl®, Ban® ,Fungamyl® and Duramyl®, all
available from Novo Nordisk A/S Denmark. WO95/26397 describes other suitable amylases
: α-amylases characterised by having a specific activity at least 25% higher than
the specific activity of Termamyl® at a temperature range of 25°C to 55°C and at a
pH value in the range of 8 to 10, measured by the Phadebas® α-amylase activity assay.
Suitable are variants of the above enzymes, described in WO96/23873 (Novo Nordisk).
Other amylolytic enzymes with improved properties with respect to the activity level
and the combination of thermostability and a higher activity level are described in
WO95/35382. Preferred complementary amylases for the present invention are the amylases
sold under the tradename Purafect Ox Am
R described in WO 94/18314, WO96/05295 sold by Genencor; Termamyl®, Fungamyl ®, Ban®
Natalase® and Duramyl®, all available from Novo Nordisk A/S and Maxamyl® by Gist-Brocades.
[0125] Said complementary amylase is generally incorporated in the detergent compositions
of the present invention a level of from 0.0001% to 2%, preferably from 0.00018% to
0.06%, more preferably from 0.00024% to 0.048% pure enzyme by weight of the composition.
Preferably a weight of pure enzyme ratio of specific amylase to the complementary
amylase is comprised between 9:1 to 1:9, more preferably between 4:1 to 1:4, and most
preferably between 2:1 and 1:2.
[0126] The above-mentioned enzymes may be of any suitable origin, such as vegetable, animal,
bacterial, fungal and yeast origin. Origin can further be mesophilic or extremophilic
(psychrophilic, psychrotrophic, thermophilic, barophilic, alkalophilic, acidophilic,
halophilic, etc.). Purified or non-purified forms of these enzymes may be used. Also
included by definition, are mutants of native enzymes. Mutants can be obtained e.g.
by protein and/or genetic engineering, chemical and/or physical modifications of native
enzymes. Common practice as well is the expression of the enzyme via host organisms
in which the genetic material responsible for the production of the enzyme has been
cloned.
[0127] Said enzymes are normally incorporated in the detergent composition at levels from
0.0001% to 2% of active enzyme by weight of the detergent composition. The enzymes
can be added as separate single ingredients (prills, granulates, stabilized liquids,
etc... containing one enzyme) or as mixtures of two or more enzymes ( e.g. cogranulates
).
[0128] Other suitable detergent ingredients that can be added are enzyme oxidation scavengers
which are described in Copending European Patent application 92870018.6 filed on January
31, 1992. Examples of such enzyme oxidation scavengers are ethoxylated tetraethylene
polyamines.
[0129] A range of enzyme materials and means for their incorporation into synthetic detergent
compositions is also disclosed in WO 9307263 A and WO 9307260 A to Genencor International,
WO 8908694 A to Novo, and U.S. 3,553,139, January 5, 1971 to McCarty et al. Enzymes
are further disclosed in U.S. 4,101,457, Place et al, July 18, 1978, and in U.S. 4,507,219,
Hughes, March 26, 1985. Enzyme materials useful for liquid detergent formulations,
and their incorporation into such formulations, are disclosed in U.S. 4,261,868, Hora
et al, April 14, 1981. Enzymes for use in detergents can be stabilised by various
techniques. Enzyme stabilisation techniques are disclosed and exemplified in U.S.
3,600,319, August 17, 1971, Gedge et al, EP 199,405 and EP 200,586, October 29, 1986,
Venegas. Enzyme stabilisation systems are also described, for example, in U.S. 3,519,570.
A useful Bacillus, sp. AC13 giving proteases, xylanases and cellulases, is described
in WO 9401532 A to Novo.
Bleaching agent
[0130] A highly preferred component of the composition of detergent components is a bleaching
agent. Suitable bleaching agents include chlorine and oxygen-releasing bleaching agents.
[0131] In one preferred aspect the oxygen-releasing bleaching agent contains a hydrogen
peroxide source and an organic peroxyacid bleach precursor compound. The production
of the organic peroxyacid occurs by an in situ reaction of the precursor with a source
of hydrogen peroxide. Preferred sources of hydrogen peroxide include inorganic perhydrate
bleaches. In an alternative preferred aspect a preformed organic peroxyacid is incorporated
directly into the composition. Compositions containing mixtures of a hydrogen peroxide
source and organic peroxyacid precursor in combination with a preformed organic peroxyacid
are also envisaged.
Inorganic perhydrate bleaches
[0132] The compositions of detergent components preferably include a hydrogen peroxide source,
as an oxygen-releasing bleach. Suitable hydrogen peroxide sources include the inorganic
perhydrate salts.
[0133] The inorganic perhydrate salts are normally incorporated in the form of the sodium
salt at a level of from 1% to 40% by weight, more preferably from 2% to 30% by weight
and most preferably from 5% to 25% by weight of the compositions.
[0134] Examples of inorganic perhydrate salts include perborate, percarbonate, perphosphate,
persulfate and persilicate salts. The inorganic perhydrate salts are normally the
alkali metal salts. The inorganic perhydrate salt may be included as the crystalline
solid without additional protection. For certain perhydrate salts however, the preferred
executions of such granular compositions utilize a coated form of the material which
provides better storage stability for the perhydrate salt in the granular product.
[0135] Sodium perborate can be in the form of the monohydrate of nominal formula NaBO
2H
2O
2 or the tetrahydrate NaBO
2H
2O
2.3H
2O.
[0136] Alkali metal percarbonates, particularly sodium percarbonate are preferred perhydrates
for inclusion in compositions in accordance with the invention. Sodium percarbonate
is an addition compound having a formula corresponding to 2Na
2CO
3.3H
2O
2, and is available commercially as a crystalline solid. Sodium percarbonate, being
a hydrogen peroxide addition compound tends on dissolution to release the hydrogen
peroxide quite rapidly which can increase the tendency for localised high bleach concentrations
to arise. The percarbonate is most preferably incorporated into such compositions
in a coated form which provides in-product stability.
[0137] A suitable coating material providing in product stability comprises mixed salt of
a water soluble alkali metal sulphate and carbonate. Such coatings together with coating
processes have previously been described in GB-1,466,799, granted to Interox on 9th
March 1977. The weight ratio of the mixed salt coating material to percarbonate lies
in the range from 1 : 200 to 1 : 4, more preferably from 1 : 99 to 1 : 9, and most
preferably from 1 : 49 to 1 : 19. Preferably, the mixed salt is of sodium sulphate
and sodium carbonate which has the general formula Na
2SO
4.n.Na
2CO
3 wherein n is from 0.1 to 3, preferably n is from 0.3 to 1.0 and most preferably n
is from 0.2 to 0.5.
[0138] Another suitable coating material providing in product stability, comprises sodium
silicate of SiO
2 : Na
2O ratio from 1.8 : 1 to 3.0 : 1, preferably 1.8:1 to 2.4:1, and/or sodium metasilicate,
preferably applied at a level of from 2% to 10%, (normally from 3% to 5%) of SiO
2 by weight of the inorganic perhydrate salt. Magnesium silicate can also be included
in the coating. Coatings that contain silicate and borate salts or boric acids or
other inorganics are also suitable.
[0139] Other coatings which contain waxes, oils, fatty soaps can also be used advantageously
within the present invention.
[0140] Potassium peroxymonopersulfate is another inorganic perhydrate salt of utility in
the compositions herein.
Peroxyacid bleach precursor
[0141] Peroxyacid bleach precursors are compounds which react with hydrogen peroxide in
a perhydrolysis reaction to produce a peroxyacid. Generally peroxyacid bleach precursors
may be represented as
where L is a leaving group and X is essentially any functionality, such that on perhydrolysis
the structure of the peroxyacid produced is
[0142] Peroxyacid bleach precursor compounds are preferably incorporated at a level of from
0.5% to 20% by weight, more preferably from 1% to 10% by weight, most preferably from
1.5% to 5% by weight of the compositions.
[0143] Suitable peroxyacid bleach precursor compounds typically contain one or more N- or
O-acyl groups, which precursors can be selected from a wide range of classes. Suitable
classes include anhydrides, esters, imides, lactams and acylated derivatives of imidazoles
and oximes. Examples of useful materials within these classes are disclosed in GB-A-1586789.
Suitable esters are disclosed in GB-A-836988, 864798, 1147871, 2143231 and EP-A-0170386.
Leaving groups
[0144] The leaving group, hereinafter L group, must be sufficiently reactive for the perhydrolysis
reaction to occur within the optimum time frame (e.g., a wash cycle). However, if
L is too reactive, this activator will be difficult to stabilise for use in a bleaching
composition.
[0145] Preferred L groups are selected from the group consisting of:
and mixtures thereof, wherein R
1 is an alkyl, aryl, or alkaryl group containing from 1 to 14 carbon atoms, R
3 is an alkyl chain containing from 1 to 8 carbon atoms, R
4 is H or R
3, R
5 is an alkenyl chain containing from 1 to 8 carbon atoms and Y is H or a solubilizing
group. Any of R
1, R
3 and R
4 may be substituted by essentially any functional group including, for example alkyl,
hydroxy, alkoxy, halogen, amine, nitrosyl, amide and ammonium or alkyl ammonium groups.
[0146] The preferred solubilizing groups are -SO
3 -M
+, -CO
2 -M
+, -SO
4 -M
+, -N
+(R
3)
4X
- and O<--N(R
3)
3 and most preferably -SO
3 -M
+ and -CO
2 -M
+ wherein R
3 is an alkyl chain containing from 1 to 4 carbon atoms, M is a cation which provides
solubility to the bleach activator and X is an anion which provides solubility to
the bleach activator. Preferably, M is an alkali metal, ammonium or substituted ammonium
cation, with sodium and potassium being most preferred, and X is a halide, hydroxide,
methylsulfate or acetate anion.
Perbenzoic acid precursor
[0147] Perbenzoic acid precursor compounds provide perbenzoic acid on perhydrolysis.
[0148] Suitable O-acylated perbenzoic acid precursor compounds include the substituted and
unsubstituted benzoyl oxybenzene sulfonates, including for example benzoyl oxybenzene
sulfonate:
[0149] Also suitable are the benzoylation products of sorbitol, glucose, and all saccharides
with benzoylating agents, including for example:
[0150] Perbenzoic acid precursor compounds of the imide type include N-benzoyl succinimide,
tetrabenzoyl ethylene diamine and the N-benzoyl substituted ureas. Suitable imidazole
type perbenzoic acid precursors include N-benzoyl imidazole and N-benzoyl benzimidazole
and other useful N-acyl group-containing perbenzoic acid precursors include N-benzoyl
pyrrolidone, dibenzoyl taurine and benzoyl pyroglutamic acid.
[0151] Other perbenzoic acid precursors include the benzoyl diacyl peroxides, the benzoyl
tetraacyl peroxides, and the compound having the formula:
[0152] Phthalic anhydride is another suitable perbenzoic acid precursor compound herein:
[0153] Suitable N-acylated lactam perbenzoic acid precursors have the formula:
wherein n is from 0 to 8, preferably from 0 to 2, and R
6 is a benzoyl group.
Perbenzoic acid derivative precursors
[0154] Perbenzoic acid derivative precursors provide substituted perbenzoic acids on perhydrolysis.
[0155] Suitable substituted perbenzoic acid derivative precursors include any of the herein
disclosed perbenzoic precursors in which the benzoyl group is substituted by essentially
any non-positively charged (i.e.; non-cationic) functional group including, for example
alkyl, hydroxy, alkoxy, halogen, amine, nitrosyl and amide groups.
[0156] A preferred class of substituted perbenzoic acid precursor compounds are the amide
substituted compounds of the following general formulae:
wherein R
1 is an aryl or alkaryl group with from 1 to 14 carbon atoms, R
2 is an arylene, or alkarylene group containing from 1 to 14 carbon atoms, and R
5 is H or an alkyl, aryl, or alkaryl group containing 1 to 10 carbon atoms and L can
be essentially any leaving group. R
1 preferably contains from 6 to 12 carbon atoms. R
2 preferably contains from 4 to 8 carbon atoms. R
1 may be aryl, substituted aryl or alkylaryl containing branching, substitution, or
both and may be sourced from either synthetic sources or natural sources including
for example, tallow fat. Analogous structural variations are permissible for R
2. The substitution can include alkyl, aryl, halogen, nitrogen, sulphur and other typical
substituent groups or organic compounds. R
5 is preferably H or methyl. R
1 and R
5 should not contain more than 18 carbon atoms in total. Amide substituted bleach activator
compounds of this type are described in EP-A-0170386.
Cationic peroxyacid precursors
[0157] Cationic peroxyacid precursor compounds produce cationic peroxyacids on perhydrolysis.
[0158] Typically, cationic peroxyacid precursors are formed by substituting the peroxyacid
part of a suitable peroxyacid precursor compound with a positively charged functional
group, such as an ammonium or alkyl ammonium group, preferably an ethyl or methyl
ammonium group. Cationic peroxyacid precursors are typically present in the compositions
as a salt with a suitable anion, such as for example a halide ion or a methylsulfate
ion.
[0159] The peroxyacid precursor compound to be so cationically substituted may be a perbenzoic
acid, or substituted derivative thereof, precursor compound as described hereinbefore.
Alternatively, the peroxyacid precursor compound may be an alkyl percarboxylic acid
precursor compound or an amide substituted alkyl peroxyacid precursor as described
hereinafter
[0160] Cationic peroxyacid precursors are described in U.S. Patents 4,904,406; 4,751,015;
4,988,451; 4,397,757; 5,269,962; 5,127,852; 5,093,022; 5,106,528; U.K. 1,382,594;
EP 475,512, 458,396 and 284,292; and in JP 87-318,332.
[0161] Suitable cationic peroxyacid precursors include any of the ammonium or alkyl ammonium
substituted alkyl or benzoyl oxybenzene sulfonates, N-acylated caprolactams, and monobenzoyltetraacetyl
glucose benzoyl peroxides.
[0162] A preferred cationically substituted benzoyl oxybenzene sulfonate is the 4-(trimethyl
ammonium) methyl derivative of benzoyl oxybenzene sulfonate:
[0163] A preferred cationically substituted alkyl oxybenzene sulfonate has the formula:
[0164] Preferred cationic peroxyacid precursors of the N-acylated caprolactam class include
the trialkyl ammonium methylene benzoyl caprolactams, particularly trimethyl ammonium
methylene benzoyl caprolactam:
[0165] Other preferred cationic peroxyacid precursors of the N-acylated caprolactam class
include the trialkyl ammonium methylene alkyl caprolactams:
where n is from 0 to 12, particularly from 1 to 5.
[0166] Another preferred cationic peroxyacid precursor is 2-(N,N,N-trimethyl ammonium) ethyl
sodium 4-sulphophenyl carbonate chloride.
Alkyl percarboxylic acid bleach precursors
[0167] Alkyl percarboxylic acid bleach precursors form percarboxylic acids on perhydrolysis.
Preferred precursors of this type provide peracetic acid on perhydrolysis.
[0168] Preferred alkyl percarboxylic precursor compounds of the imide type include the N,N,N
1N
1 tetra acetylated alkylene diamines wherein the alkylene group contains from 1 to
6 carbon atoms, particularly those compounds in which the alkylene group contains
1, 2 and 6 carbon atoms. Tetraacetyl ethylene diamine (TAED) is particularly preferred.
[0169] Other preferred alkyl percarboxylic acid precursors include sodium 3,5,5-tri-methyl
hexanoyloxybenzene sulfonate (iso-NOBS), sodium nonanoyloxybenzene sulfonate (NOBS),
sodium acetoxybenzene sulfonate (ABS) and penta acetyl glucose.
Amide substituted alkyl peroxyacid precursors
[0170] Amide substituted alkyl peroxyacid precursor compounds are also suitable, including
those of the following general formulae:
wherein R
1 is an alkyl group with from 1 to 14 carbon atoms, R
2 is an alkylene group containing from 1 to 14 carbon atoms, and R
5 is H or an alkyl group containing 1 to 10 carbon atoms and L can be essentially any
leaving group. R
1 preferably contains from 6 to 12 carbon atoms. R
2 preferably contains from 4 to 8 carbon atoms. R
1 may be straight chain or branched alkyl containing branching, substitution, or both
and may be sourced from either synthetic sources or natural sources including for
example, tallow fat. Analogous structural variations are permissible for R
2. The substitution can include alkyl, halogen, nitrogen, sulphur and other typical
substituent groups or organic compounds. R
5 is preferably H or methyl. R
1 and R
5 should not contain more than 18 carbon atoms in total. Amide substituted bleach activator
compounds of this type are described in EP-A-0170386.
Benzoxazin organic peroxvacid precursors
[0171] Also suitable are precursor compounds of the benzoxazin-type, as disclosed for example
in EP-A-332,294 and EP-A-482,807, particularly those having the formula:
including the substituted benzoxazins of the type
wherein R
1 is H, alkyl, alkaryl, aryl, arylalkyl, and wherein R
2, R
3, R
4, and R
5 may be the same or different substituents selected from H, halogen, alkyl, alkenyl,
aryl, hydroxyl, alkoxyl, amino, alkyl amino, COOR
6 (wherein R
6 is H or an alkyl group) and carbonyl functions.
[0172] An especially preferred precursor of the benzoxazin-type is:
Preformed organic peroxyacid
[0173] The organic peroxyacid bleaching system may contain, in addition to, or as an alternative
to, an organic peroxyacid bleach precursor compound, a preformed organic peroxyacid
, typically at a level of from 0.5% to 25% by weight, more preferably from 1% to 10%
by weight of the composition.
[0174] A preferred class of organic peroxyacid compounds are the amide substituted compounds
of the following general formulae:
wherein R
1 is an alkyl, aryl or alkaryl group with from 1 to 14 carbon atoms, R
2 is an alkylene, arylene, and alkarylene group containing from 1 to 14 carbon atoms,
and R
5 is H or an alkyl, aryl, or alkaryl group containing 1 to 10 carbon atoms. R
1 preferably contains from 6 to 12 carbon atoms. R
2 preferably contains from 4 to 8 carbon atoms. R
1 may be straight chain or branched alkyl, substituted aryl or alkylaryl containing
branching, substitution, or both and may be sourced from either synthetic sources
or natural sources including for example, tallow fat. Analogous structural variations
are permissible for R
2. The substitution can include alkyl, aryl, halogen, nitrogen, sulphur and other typical
substituent groups or organic compounds. R
5 is preferably H or methyl. R
1 and R
5 should not contain more than 18 carbon atoms in total. Amide substituted organic
peroxyacid compounds of this type are described in EP-A-0170386.
[0175] Other organic peroxyacids include diacyl and tetraacylperoxides, especially diperoxydodecanedioc
acid, diperoxytetradecanedioc acid, and diperoxyhexadecanedioc acid. Dibenzoyl peroxide
is a preferred organic peroxyacid herein. Mono- and diperazelaic acid, mono- and diperbrassylic
acid, and N-phthaloylaminoperoxicaproic acid are also suitable herein.
Controlled rate of release - means
[0176] A means may be provided for controlling the rate of release of bleaching agent, particularly
oxygen bleach to the wash solution.
[0177] Means for controlling the rate of release of the bleach may provide for controlled
release of peroxide species to the wash solution. Such means could, for example, include
controlling the release of any inorganic perhydrate salt, acting as a hydrogen peroxide
source, to the wash solution.
[0178] Another mechanism for controlling the rate of release of bleach may be by coating
the bleach with a coating designed to provide the controlled release. The coating
may therefore, for example, comprise a poorly water soluble material, or be a coating
of sufficient thickness that the kinetics of dissolution of the thick coating provide
the controlled rate of release.
[0179] The coating material may be applied using various methods. Any coating material is
typically present at a weight ratio of coating material to bleach of from 1:99 to
1:2, preferably from 1:49 to 1:9.
[0180] Suitable coating materials include triglycerides (e.g. partially) hydrogenated vegetable
oil, soy bean oil, cotton seed oil) mono or diglycerides, microcrystalline waxes,
gelatin, cellulose, fatty acids and any mixtures thereof.
[0181] Other suitable coating materials can comprise the alkali and alkaline earth metal
sulphates, silicates and carbonates, including calcium carbonate and silicas.
[0182] A preferred coating material, particularly for an inorganic perhydrate salt bleach
source, comprises sodium silicate of SiO
2 : Na
2O ratio from 1.8 : 1 to 3.0 : 1, preferably 1.8:1 to 2.4:1, and/or sodium metasilicate,
preferably applied at a level of from 2% to 10%, (normally from 3% to 5%) of SiO
2 by weight of the inorganic perhydrate salt. Magnesium silicate can also be included
in the coating.
[0183] Any inorganic salt coating materials may be combined with organic binder materials
to provide composite inorganic salt/organic binder coatings. Suitable binders include
the C
10-C
20 alcohol ethoxylates containing from 5 - 100 moles of ethylene oxide per mole of alcohol
and more preferably the C
15-C
20 primary alcohol ethoxylates containing from 20 - 100 moles of ethylene oxide per
mole of alcohol.
[0184] Other preferred binders include certain polymeric materials. Polyvinylpyrrolidones
with an average molecular weight of from 12,000 to 700,000 and polyethylene glycols
(PEG) with an average molecular weight of from 600 to 5 x 10
6 preferably 1000 to 400,000 most preferably 1000 to 10,000 are examples of such polymeric
materials.
[0185] Copolymers of maleic anhydride with ethylene, methylvinyl ether or methacrylic acid,
the maleic anhydride constituting at least 20 mole percent of the polymer are further
examples of polymeric materials useful as binder agents. These polymeric materials
may be used as such or in combination with solvents such as water, propylene glycol
and the above mentioned C
10-C
20 alcohol ethoxylates containing from 5 - 100 moles of ethylene oxide per mole. Further
examples of binders include the C
10-C
20 mono- and diglycerol ethers and also the C
10-C
20 fatty acids.
[0186] Cellulose derivatives such as methylcellulose, carboxymethylcellulose and hydroxyethylcellulose,
and homo- or co-polymeric polycarboxylic acids or their salts are other examples of
binders suitable for use herein.
[0187] One method for applying the coating material involves agglomeration. Preferred agglomeration
processes include the use of any of the organic binder materials described hereinabove.
Any conventional agglomerator/mixer may be used including, but not limited to pan,
rotary drum and vertical blender types. Molten coating compositions may also be applied
either by being poured onto, or spray atomized onto a moving bed of bleaching agent.
[0188] Other means of providing the required controlled release include mechanical means
for altering the physical characteristics of the bleach to control its solubility
and rate of release. Suitable protocols could include compression, mechanical injection,
manual injection, and adjustment of the solubility of the bleach compound by selection
of particle size of any particulate component.
[0189] Whilst the choice of particle size will depend both on the composition of the particulate
component, and the desire to meet the desired controlled release kinetics, it is desirable
that the particle size should be more than 500 micrometers, preferably having an average
particle diameter of from 800 to 1200 micrometers.
[0190] Additional protocols for providing the means of controlled release include the suitable
choice of any other components of the detergent composition matrix such that when
the composition is introduced to the wash solution the ionic strength environment
therein provided enables the required controlled release kinetics to be achieved.
Metal-containing bleach catalyst
[0191] The compositions described herein which contain bleach as an detergent component
may additionally contain as a preferred component, a metal containing bleach catalyst.
Preferably the metal containing bleach catalyst is a transition metal containing bleach
catalyst, more preferably a manganese or cobalt-containing bleach catalyst.
[0192] A suitable type of bleach catalyst is a catalyst comprising a heavy metal cation
of defined bleach catalytic activity, such as copper, iron cations, an auxiliary metal
cation having little or no bleach catalytic activity, such as zinc or aluminium cations,
and a sequestrant having defined stability constants for the catalytic and auxiliary
metal cations, particularly ethylenediaminetetraacetic acid, ethylenediaminetetra(methylenephosphonic
acid) and water-soluble salts thereof. Such catalysts are disclosed in U.S. Pat. 4,430,243.
[0193] Preferred types of bleach catalysts include the manganese-based complexes disclosed
in U.S. Pat. 5,246,621 and U.S. Pat. 5,244,594. Preferred examples of these catalysts
include Mn
IV 2(u-O)
3(1,4,7-trimethyl-1,4,7-triazacyclononane)
2-(PF
6)
2, Mn
III 2(u-O)
1(u-OAc)
2(1,4,7-trimethyl-1,4,7-triazacyclononane)
2-(ClO
4)
2, Mn
IV 4(u-O)
6(1,4,7-triazacyclononane)
4-(ClO
4)2, Mn
IIIMn
IV 4(u-O)
1(u-OAc)
2- (1,4,7-trimethyl-1,4,7-triazacyclononane)
2-(ClO
4)
3, and mixtures thereof. Others are described in European patent application publication
no. 549,272. Other ligands suitable for use herein include 1,5,9-trimethyl-1,5,9-triazacyclododecane,
2-methyl-1,4,7-triazacyclononane, 2-methyl-1,4,7-triazacyclononane, 1,2,4,7-tetramethyl-1,4,7-triazacyclononane,
and mixtures thereof.
[0194] The bleach catalysts useful in the compositions herein may also be selected as appropriate
for the present invention. For examples of suitable bleach catalysts see U.S. Pat.
4,246,612 and U.S. Pat. 5,227,084. See also U.S. Pat. 5,194,416 which teaches mononuclear
manganese (IV) complexes such as Mn(1,4,7-trimethyl-1,4,7-triazacyclononane)(OCH
3)
3-(PF
6).
[0195] Still another type of bleach catalyst, as disclosed in U.S. Pat. 5,114,606, is a
water-soluble complex of manganese (III), and/or (IV) with a ligand which is a non-carboxylate
polyhydroxy compound having at least three consecutive C-OH groups. Preferred ligands
include sorbitol, iditol, dulsitol, mannitol, xylithol, arabitol, adonitol, meso-erythritol,
meso-inositol, lactose, and mixtures thereof.
[0196] U.S. Pat. 5,114,611 teaches a bleach catalyst comprising a complex of transition
metals, including Mn, Co, Fe, or Cu, with an non-(macro)-cyclic ligand. Said ligands
are of the formula:
wherein R
1, R
2, R
3, and R
4 can each be selected from H, substituted alkyl and aryl groups such that each R
1-N=C-R
2 and R
3-C=N-R
4 form a five or six-membered ring. Said ring can further be substituted. B is a bridging
group selected from O, S. CR
5R
6, NR
7 and C=O, wherein R
5, R
6, and R
7 can each be H, alkyl, or aryl groups, including substituted or unsubstituted groups.
Preferred ligands include pyridine, pyridazine, pyrimidine, pyrazine, imidazole, pyrazole,
and triazole rings. Optionally, said rings may be substituted with substituents such
as alkyl, aryl, alkoxy, halide, and nitro. Particularly preferred is the ligand 2,2'-bispyridylamine.
Preferred bleach catalysts include Co, Cu, Mn, Fe,-bispyridylmethane and -bispyridylamine
complexes. Highly preferred catalysts include Co(2,2'-bispyridylamine)Cl
2, Di(isothiocyanato)bispyridylamine-cobalt (II), trisdipyridylamine-cobalt(II) perchlorate,
Co(2,2-bispyridylamine)
2O
2ClO
4, Bis-(2,2'-bispyridylamine) copper(II) perchlorate, tris(di-2-pyridylamine) iron(II)
perchlorate, and mixtures thereof.
[0197] Preferred examples include binuclear Mn complexes with tetra-N-dentate and bi-N-dentate
ligands, including N
4Mn
III(u-O)
2Mn
IVN
4)
+ and [Bipy
2Mn
III(u-O)
2Mn
IVbipy
2]-(ClO
4)
3.
[0198] While the structures of the bleach-catalyzing manganese complexes of the present
invention have not been elucidated, it may be speculated that they comprise chelates
or other hydrated coordination complexes which result from the interaction of the
carboxyl and nitrogen atoms of the ligand with the manganese cation. Likewise, the
oxidation state of the manganese cation during the catalytic process is not known
with certainty, and may be the (+II), (+III), (+IV) or (+V) valence state. Due to
the ligands' possible six points of attachment to the manganese cation, it may be
reasonably speculated that multi-nuclear species and/or "cage" structures may exist
in the aqueous bleaching media. Whatever the form of the active Mn
.ligand species which actually exists, it functions in an apparently catalytic manner
to provide improved bleaching performances on stubborn stains such as tea, ketchup,
coffee, wine, juice, and the like.
[0199] Other bleach catalysts are described, for example, in European patent application,
publication no. 408,131 (cobalt complex catalysts), European patent applications,
publication nos. 384,503, and 306,089 (metallo-porphyrin catalysts), U.S. 4,728,455
(manganese/multidentate ligand catalyst), U.S. 4,711,748 and European patent application,
publication no. 224,952, (absorbed manganese on aluminosilicate catalyst), U.S. 4,601,845
(aluminosilicate support with manganese and zinc or magnesium salt), U.S. 4,626,373
(manganese/ligand catalyst), U.S. 4,119,557 (ferric complex catalyst), German Pat.
specification 2,054,019 (cobalt chelant catalyst) Canadian 866,191 (transition metal-containing
salts), U.S. 4,430,243 (chelants with manganese cations and non-catalytic metal cations),
and U.S. 4,728,455 (manganese gluconate catalysts).
[0200] Other preferred examples include cobalt (III) catalysts having the formula:
Co[(NH
3)
nM'
mB'
bT'
tQ
qP
p] Y
y
wherein cobalt is in the +3 oxidation state; n is an integer from 0 to 5 (preferably
4 or 5; most preferably 5); M' represents a monodentate ligand; m is an integer from
0 to 5 (preferably 1 or 2; most preferably 1); B' represents a bidentate ligand; b
is an integer from 0 to 2; T' represents a tridentate ligand; t is 0 or 1; Q is a
tetradentate ligand; q is 0 or 1; P is a pentadentate ligand; p is 0 or 1; and n +
m + 2b + 3t + 4q + 5p = 6; Y is one or more appropriately selected counteranions present
in a number y, where y is an integer from 1 to 3 (preferably 2 to 3; most preferably
2 when Y is a -1 charged anion), to obtain a charge-balanced salt, preferred Y are
selected from the group consisting of chloride, nitrate, nitrite, sulfate, citrate,
acetate, carbonate, and combinations thereof; and wherein further at least one of
the coordination sites attached to the cobalt is labile under automatic dishwashing
use conditions and the remaining co-ordination sites stabilise the cobalt under automatic
dishwashing conditions such that the reduction potential for cobalt (III) to cobalt
(II) under alkaline conditions is less than 0.4 volts (preferably less than 0.2 volts)
versus a normal hydrogen electrode.
[0201] Preferred cobalt catalysts of this type have the formula:
[Co(NH
3)
n(M')
m] Y
y
wherein n is an integer from 3 to 5 (preferably 4 or 5; most preferably 5); M' is
a labile coordinating moiety, preferably selected from the group consisting of chlorine,
bromine, hydroxide, water, and (when m is greater than 1) combinations thereof; m
is an integer from 1 to 3 (preferably 1 or 2; most preferably 1); m+n = 6; and Y is
an appropriately selected counteranion present in a number y, which is an integer
from 1 to 3 (preferably 2 to 3; most preferably 2 when Y is a -1 charged anion), to
obtain a charge-balanced salt.
[0202] The preferred cobalt catalyst of this type useful herein are cobalt pentaamine chloride
salts having the formula [Co(NH
3)
5Cl] Y
y, and especially [Co(NH
3)
5Cl]Cl
2.
[0203] More preferred are the present invention compositions which utilize cobalt (III)
bleach catalysts having the formula:
[Co(NH
3)
n(M)
m(B)
b] T
y
wherein cobalt is in the +3 oxidation state; n is 4 or 5 (preferably 5); M is one
or more ligands coordinated to the cobalt by one site; m is 0, 1 or 2 (preferably
1); B is a ligand co-ordinated to the cobalt by two sites; b is 0 or 1 (preferably
0), and when b=0, then m+n = 6, and when b=1, then m=0 and n=4; and T is one or more
appropriately selected counteranions present in a number y, where y is an integer
to obtain a charge-balanced salt (preferably y is 1 to 3; most preferably 2 when T
is a -1 charged anion); and wherein further said catalyst has a base hydrolysis rate
constant of less than 0.23 M
-1 s
-1 (25°C).
[0204] Preferred T are selected from the group consisting of chloride, iodide, I
3 -, formate, nitrate, nitrite, sulfate, sulfite, citrate, acetate, carbonate, bromide,
PF
6 -, BF
4 -, B(Ph)
4 -, phosphate, phosphite, silicate, tosylate, methanesulfonate, and combinations thereof.
Optionally, T can be protonated if more than one anionic group exists in T, e.g.,
HPO
4 2-, HCO
3 -, H
2PO
4 -, etc. Further, T may be selected from the group consisting of non-traditional inorganic
anions such as anionic surfactants (e.g., linear alkylbenzene sulfonates (LAS), alkyl
sulfates (AS), alkylethoxysulfonates (AES), etc.) and/or anionic polymers (e.g., polyacrylates,
polymethacrylates, etc.).
[0205] The M moieties include, but are not limited to, for example, F-, SO
4 -2, NCS-, SCN-, S
2O
3 -2, NH
3, PO
4 3-, and carboxylates (which preferably are mono-carboxylates, but more than one carboxylate
may be present in the moiety as long as the binding to the cobalt is by only one carboxylate
per moiety, in which case the other carboxylate in the M moiety may be protonated
or in its salt form). Optionally, M can be protonated if more than one anionic group
exists in M (e.g., HPO
4 2-, HCO
3 -, H
2PO
4 -, HOC(O)CH
2C(O)O-, etc.) Preferred M moieties are substituted and unsubstituted C
1-C
30 carboxylic acids having the formulas:
RC(O)O-
wherein R is preferably selected from the group consisting of hydrogen and C
1-C
30 (preferably C
1-C
18) unsubstituted and substituted alkyl, C
6-C
30 (preferably C
6-C
18) unsubstituted and substituted aryl, and C
3-C
30 (preferably C
5-C
18) unsubstituted and substituted heteroaryl, wherein substituents are selected from
the group consisting of-NR'
3, -NR'
4 +, -C(O)OR', -OR', -C(O)NR'
2, wherein R' is selected from the group consisting of hydrogen and C
1-C
6 moieties. Such substituted R therefore include the moieties -(CH
2)
nOH and -(CH
2)
nNR'
4 +, wherein n is an integer from 1 to 16, preferably from 2 to 10, and most preferably
from 2 to 5.
[0206] Most preferred M are carboxylic acids having the formula above wherein R is selected
from the group consisting of hydrogen, methyl, ethyl, propyl, straight or branched
C
4-C
12 alkyl, and benzyl. Most preferred R is methyl. Preferred carboxylic acid M moieties
include formic, benzoic, octanoic, nonanoic, decanoic, dodecanoic, malonic, maleic,
succinic, adipic, phthalic, 2-ethylhexanoic, naphthenoic, oleic, palmitic, triflate,
tartrate, stearic, butyric, citric, acrylic, aspartic, fumaric, lauric, linoleic,
lactic, malic, and especially acetic acid.
[0207] The B moieties include carbonate, di- and higher carboxylates (e.g., oxalate, malonate,
malic, succinate, maleate), picolinic acid, and alpha and beta amino acids (e.g.,
glycine, alanine, beta-alanine, phenylalanine).
[0208] Cobalt bleach catalysts useful herein are known, being described for example along
with their base hydrolysis rates, in M. L. Tobe, "Base Hydrolysis of Transition-Metal
Complexes",
Adv. Inorg. Bioinorg. Mech., (1983), 2, pages 1-94. For example, Table 1 at page 17, provides the base hydrolysis
rates (designated therein as k
OH) for cobalt pentaamine catalysts complexed with oxalate (k
OH= 2.5 x 10
-4 M
-1 s
-1 (25° C)), NCS- (k
OH= 5.0 x 10
-4 M
-1 s
-1 (25°C)), formate (k
OH= 5.8 x 10
-4 M
-1 s
-1 (25°C)), and acetate (k
OH= 9.6 x 10
-4 M
-1 s
-1 (25°C)). The most preferred cobalt catalyst useful herein are cobalt pentaamine acetate
salts having the formula [Co(NH
3)
5OAc] T
y, wherein OAc represents an acetate moiety, and especially cobalt pentaamine acetate
chloride, [Co(NH
3)
5OAc]Cl
2; as well as [Co(NH
3)
5OAc](OAc)
2; [Co(NH
3)
5OAc](PF
6)
2; [Co(NH
3)
5OAc](SO
4); [Co-(NH
3)
5OAc](BF
4)
2; and [Co(NH
3)
5OAc](NO
3)
2 (herein "PAC").
[0209] These cobalt catalysts are readily prepared by known procedures, such as taught for
example in the Tobe article hereinbefore and the references cited therein, in U.S.
Patent 4,810,410, to Diakun et al, issued March 7,1989,
J. Chem. Ed. (1989),
66 (12), 1043-45; The Synthesis and Characterization of Inorganic Compounds, W.L. Jolly
(Prentice-Hall; 1970), pp. 461-3;
Inorg. Chem.,
18, 1497-1502 (1979);
Inorg. Chem.,
21, 2881-2885 (1982);
Inorg Chem.,
18 2023-2025 (1979); Inorg. Synthesis, 173-176 (1960); and
Journal of Physical Chemistry,
56, 22-25 (1952); as well as the synthesis examples provided hereinafter.
[0210] Cobalt catalysts suitable for incorporation into the detergent tablets of the present
invention may be produced according to the synthetic routes disclosed in U.S. Patent
Nos. 5,559,261, 5,581,005, and 5,597,936, the disclosures of which are herein incorporated
by reference.
[0211] These catalysts may be co-processed with adjunct materials so as to reduce the colour
impact if desired for the aesthetics of the product, or to be included in enzyme-containing
particles as exemplified hereinafter, or the compositions may be manufactured to contain
catalyst "speckles".
Organic polymeric compound
[0212] Organic polymeric compounds may be added as preferred components of the detergent
tablets in accord with the invention. By organic polymeric compound it is meant essentially
any polymeric organic compound commonly found in detergent compositions having dispersant,
anti-redeposition, soil release agents or other detergency properties.
[0213] Organic polymeric compound is typically incorporated in the detergent compositions
of the invention at a level of from 0.1% to 30%, preferably from 0.5% to 15%, most
preferably from 1% to 10% by weight of the compositions.
[0214] Examples of organic polymeric compounds include the water soluble organic homo- or
co-polymeric polycarboxylic acids, modified polycarboxylates or their salts in which
the polycarboxylic acid comprises at least two carboxyl radicals separated from each
other by not more than two carbon atoms. Polymers of the latter type are disclosed
in GB-A-1,596,756. Examples of such salts are polyacrylates of molecular weight 2000-10000
and their copolymers with any suitable other monomer units including modified acrylic,
fumaric, maleic, itaconic, aconitic, mesaconic, citraconic and methylenemalonic acid
or their salts, maleic anhydride, acrylamide, alkylene, vinylmethyl ether, styrene
and any mixtures thereof Preferred are the copolymers of acrylic acid and maleic anhydride
having a molecular weight of from 20,000 to 100,000.
[0215] Preferred commercially available acrylic acid containing polymers having a molecular
weight below 15,000 include those sold under the tradename Sokalan PA30, PA20, PA15,
PA10 and Sokalan CP10 by BASF GmbH, and those sold under the tradename Acusol 45N,
480N, 460N by Rohm and Haas.
[0216] Preferred acrylic acid containing copolymers include those which contain as monomer
units: a) from 90% to 10%, preferably from 80% to 20% by weight acrylic acid or its
salts and b) from 10% to 90%, preferably from 20% to 80% by weight of a substituted
acrylic monomer or its salts having the general formula -[CR
2-CR
1(CO-O-R
3)]- wherein at least one of the substituents R
1, R
2 or R
3, preferably R
1 or R
2 is a 1 to 4 carbon alkyl or hydroxyalkyl group, R
1 or R
2 can be a hydrogen and R
3 can be a hydrogen or alkali metal salt. Most preferred is a substituted acrylic monomer
wherein R
1 is methyl, R
2 is hydrogen (i.e. a methacrylic acid monomer). The most preferred copolymer of this
type has a molecular weight of 3500 and contains 60% to 80% by weight of acrylic acid
and 40% to 20% by weight of methacrylic acid.
[0217] The polyamine and modified polyamine compounds are useful herein including those
derived from aspartic acid such as those disclosed in EP-A-305282, EP-A-305283 and
EP-A-351629.
[0218] Other optional polymers may polyvinyl alcohols and acetates both modified and non-modified,
cellulosics and modified cellulosics, polyoxyethylenes, polyoxypropylenes, and copolymers
thereof, both modified and non-modified, terephthalate esters of ethylene or propylene
glycol or mixtures thereof with polyoxyalkylene units.
[0219] Suitable examples are disclosed in US patent Nos. 5,591,703 , 5,597,789 and 4,490,271.
Soil Release Agents
[0220] Suitable polymeric soil release agents include those soil release agents having:
(a) one or more nonionic hydrophile components consisting essentially of (i) polyoxyethylene
segments with a degree of polymerization of at least 2, or (ii) oxypropylene or polyoxypropylene
segments with a degree of polymerization of from 2 to 10, wherein said hydrophile
segment does not encompass any oxypropylene unit unless it is bonded to adjacent moieties
at each end by ether linkages, or (iii) a mixture of oxyalkylene units comprising
oxyethylene and from 1 to 30 oxypropylene units, said hydrophile segments preferably
comprising at least 25% oxyethylene units and more preferably, especially for such
components having 20 to 30 oxypropylene units, at least 50% oxyethylene units; or
(b) one or more hydrophobe components comprising (i) C
3 oxyalkylene terephthalate segments, wherein, if said hydrophobe components also comprise
oxyethylene terephthalate, the ratio of oxyethylene terephthalate:C
3 oxyalkylene terephthalate units is 2:1 or lower, (ii) C
4-C
6 alkylene or oxy C
4-C
6 alkylene segments, or mixtures therein, (iii) poly (vinyl ester) segments, preferably
polyvinyl acetate, having a degree of polymerization of at least 2, or (iv) C
1-C
4 alkyl ether or C
4 hydroxyalkyl ether substituents, or mixtures therein, wherein said substituents are
present in the form of C
1-C
4 alkyl ether or C
4 hydroxyalkyl ether cellulose derivatives, or mixtures therein, or a combination of
(a) and (b).
[0221] Typically, the polyoxyethylene segments of (a)(i) will have a degree of polymerization
of from 200, although higher levels can be used, preferably from 3 to 150, more preferably
from 6 to 100. Suitable oxy C
4-C
6 alkylene hydrophobe segments include, but are not limited to, end-caps of polymeric
soil release agents such as MO
3S(CH
2)
nOCH
2CH
2O-, where M is sodium and n is an integer from 4-6, as disclosed in U.S. Patent 4,721,580,
issued January 26, 1988 to Gosselink.
[0222] Polymeric soil release agents useful herein also include cellulosic derivatives such
as hydroxyether cellulosic polymers, copolymeric blocks of ethylene terephthalate
or propylene terephthalate with polyethylene oxide or polypropylene oxide terephthalate,
and the like. Such agents are commercially available and include hydroxyethers of
cellulose such as METHOCEL (Dow). Cellulosic soil release agents for use herein also
include those selected from the group consisting of C
1-C
4 alkyl and C
4 hydroxyalkyl cellulose; see U.S. Patent 4,000,093, issued December 28, 1976 to Nicol,
et al.
[0223] Soil release agents characterized by poly(vinyl ester) hydrophobe segments include
graft copolymers of poly(vinyl ester), e.g., C
1-C
6 vinyl esters, preferably poly(vinyl acetate) grafted onto polyalkylene oxide backbones,
such as polyethylene oxide backbones. See European Patent Application 0 219 048, published
April 22, 1987 by Kud, et al.
[0224] Another suitable soil release agent is a copolymer having random blocks of ethylene
terephthalate and polyethylene oxide (PEO) terephthalate. The molecular weight of
this polymeric soil release agent is in the range of from 25,000 to 55,000. See U.S.
Patent 3,959,230 to Hays, issued May 25, 1976 and U.S. Patent 3,893,929 to Basadur
issued July 8, 1975.
[0225] Another suitable polymeric soil release agent is a polyester with repeat units of
ethylene terephthalate units contains 10-15% by weight of ethylene terephthalate units
together with 90-80% by weight of polyoxyethylene terephthalate units, derived from
a polyoxyethylene glycol of average molecular weight 300-5,000.
[0226] Another suitable polymeric soil release agent is a sulfonated product of a substantially
linear ester oligomer comprised of an oligomeric ester backbone of terephthaloyl and
oxyalkyleneoxy repeat units and terminal moieties covalently attached to the backbone.
These soil release agents are described fully in U.S. Patent 4,968,451, issued November
6, 1990 to J.J. Scheibel and E.P. Gosselink. Other suitable polymeric soil release
agents include the terephthalate polyesters of U.S. Patent 4,711,730, issued December
8, 1987 to Gosselink et al, the anionic end-capped oligomeric esters of U.S. Patent
4,721,580, issued January 26, 1988 to Gosselink, and the block polyester oligomeric
compounds of U.S. Patent 4,702,857, issued October 27, 1987 to Gosselink. Other polymeric
soil release agents also include the soil release agents ofU.S. Patent 4,877,896,
issued October 31, 1989 to Maldonado et al, which discloses anionic, especially sulfoarolyl,
end-capped terephthalate esters.
[0227] Another soil release agent is an oligomer with repeat units of terephthaloyl units,
sulfoisoterephthaloyl units, oxyethyleneoxy and oxy-1,2-propylene units. The repeat
units form the backbone of the oligomer and are preferably terminated with modified
isethionate end-caps. A particularly preferred soil release agent of this type comprises
one sulfoisophthaloyl unit, 5 terephthaloyl units, oxyethyleneoxy and oxy-1,2-propyleneoxy
units in a ratio of from 1.7 to 1.8, and two end-cap units of sodium 2-(2-hydroxyethoxy)-ethanesulfonate.
Heavy metal ion sequestrant
[0228] The tablets of the invention preferably contain as an optional component a heavy
metal ion sequestrant. By heavy metal ion sequestrant it is meant herein components
which act to sequester (chelate) heavy metal ions. These components may also have
calcium and magnesium chelation capacity, but preferentially they show selectivity
to binding heavy metal ions such as iron, manganese and copper.
[0229] Heavy metal ion sequestrants are generally present at a level of from 0.005% to 20%,
preferably from 0.1% to 10%, more preferably from 0.25% to 7.5% and most preferably
from 0.5% to 5% by weight of the compositions.
[0230] Heavy metal ion sequestrants, which are acidic in nature, having for example phosphonic
acid or carboxylic acid functionalities, may be present either in their acid form
or as a complex/salt with a suitable counter cation such as an alkali or alkaline
metal ion, ammonium, or substituted ammonium ion, or any mixtures thereof. Preferably
any salts/complexes are water soluble. The molar ratio of said counter cation to the
heavy metal ion sequestrant is preferably at least 1:1.
[0231] Suitable heavy metal ion sequestrants for use herein include organic phosphonates,
such as the amino alkylene poly (alkylene phosphonates), alkali metal ethane 1-hydroxy
disphosphonates and nitrilo trimethylene phosphonates. Preferred among the above species
are diethylene triamine penta (methylene phosphonate), ethylene diamine tri (methylene
phosphonate) hexamethylene diamine tetra (methylene phosphonate) and hydroxy-ethylene
1,1 diphosphonate.
[0232] Other suitable heavy metal ion sequestrant for use herein include nitrilotriacetic
acid and polyaminocarboxylic acids such as ethylenediaminotetracetic acid, ethylenetriamine
pentacetic acid, ethylenediamine disuccinic acid, ethylenediamine diglutaric acid,
2-hydroxypropylenediamine disuccinic acid or any salts thereof.
[0233] Especially preferred is ethylenediamine-N,N'-disuccinic acid (EDDS) or the alkali
metal, alkaline earth metal, ammonium, or substituted ammonium salts thereof, or mixtures
thereof. Preferred EDDS compounds are the free acid form and the sodium or magnesium
salt or complex thereof.
Crystal growth inhibitor component
[0234] The detergent tablets preferably contain a crystal growth inhibitor component, preferably
an organodiphosphonic acid component, incorporated preferably at a level of from 0.01%
to 5%, more preferably from 0.1% to 2% by weight of the compositions.
[0235] By organo diphosphonic acid it is meant herein an organo diphosphonic acid which
does not contain nitrogen as part of its chemical structure. This definition therefore
excludes the organo aminophosphonates, which however may be included in compositions
of the invention as heavy metal ion sequestrant components.
[0236] The organo diphosphonic acid is preferably a C
1-C
4 diphosphonic acid, more preferably a C
2 diphosphonic acid, such as ethylene diphosphonic acid, or most preferably ethane
1-hydroxy-1,1-diphosphonic acid (HEDP) and may be present in partially or fully ionized
form, particularly as a salt or complex.
Water-soluble sulfate salt
[0237] The detergent tablet optionally contains a water-soluble sulfate salt. Where present
the water-soluble sulfate salt is at the level of from 0.1% to 40%, more preferably
from 1% to 30%, most preferably from 5% to 25% by weight of the compositions.
[0238] The water-soluble sulfate salt may be essentially any salt of sulfate with any counter
cation. Preferred salts are selected from the sulfates of the alkali and alkaline
earth metals, particularly sodium sulfate.
Alkali Metal Silicate
[0239] An alkali metal silicate is a preferred component of the tablet of the present invention.
A preferred alkali metal silicate is sodium silicate having an SiO
2:Na
2O ratio of from 1.8 to 3.0, preferably from 1.8 to 2.4, most preferably 2.0. Sodium
silicate is preferably present at a level of less than 20%, preferably from 1% to
15%, most preferably from 3% to 12% by weight of SiO
2. The alkali metal silicate may be in the form of either the anhydrous salt or a hydrated
salt.
[0240] Alkali metal silicate may also be present as a component of an alkalinity system.
[0241] The alkalinity system also preferably contains sodium metasilicate, present at a
level of at least 0.4% SiO
2 by weight. Sodium metasilicate has a nominal SiO
2 : Na
2O ratio of 1.0. The weight ratio of said sodium silicate to said sodium metasilicate,
measured as SiO
2, is preferably from 50:1 to 5:4, more preferably from 15:1 to 2:1, most preferably
from 10:1 to 5:2.
Colourant
[0242] The term 'colourant', as used herein, means any substance that absorbs specific wavelengths
of light from the visible light spectrum. Such colourants when added to a detergent
composition have the effect of changing the visible colour and thus the appearance
of the detergent composition. Colourants may be for example either dyes or pigments.
Preferably the colourants are stable in composition in which they are to be incorported.
Thus in a composition of high pH the colourant is preferably alkali stable and in
a composition of low pH the colourant is preferably acid stable.
[0243] The first and/or second and/or optionally further phases may contain a colourant,
a mixture of colourants, coloured particles or mixture of coloured particles such
that the various phases have different visual appearances. Preferably one of either
the first or the second phases comprises a colourant. Where both the first and second
and/or subsequent phases comprise a colourant it is preferred that the colourants
have a different visual appearance.
[0244] Examples of suitable dyes include reactive dyes, direct dyes, azo dyes. Preferred
dyes include phthalocyanine dyes, anthraquinone dye, quinoline dyes, monoazo, disazo
and polyazo. More preferred dyes include anthraquinone, quinoline and monoazo dyes.
Preferred dyes include SANDOLAN E-HRL 180% (tradename), SANDOLAN MILLING BLUE (tradename),
TURQUOISE ACID BLUE (tradename) and SANDOLAN BRILLIANT GREEN (tradename) all available
from Clariant UK, HEXACOL QUINOLINE YELLOW (tradename) and HEXACOL BRILLIANT BLUE
(tradename) both available from Pointings, UK, ULTRA MARINE BLUE (tradename) available
from Holliday or LEVAFIX TURQUISE BLUE EBA (tradename) available from Bayer, USA.
[0245] The colourant may be incorporated into the phases by any suitable method. Suitable
methods include mixing all or selected detergent components with a colourant in a
drum or spraying all or selected detergent components with the colourant in a rotating
drum.
[0246] Colourant when present as a component of the first phase is present at a level of
from 0.001% to 1.5%, preferably from 0.01% to 1.0%, most preferably from 0.1% to 0.3%.
When present as a component of the second and/or optionally further phases, colourant
is generally present at a level of from 0.001% to 0.1%, more preferably from 0.005%
to 0.05%, most preferably from 0.007% to 0.02%.
Corrosion inhibitor compound
[0247] The tablets of the present invention suitable for use in dishwashing methods may
contain corrosion inhibitors preferably selected from organic silver coating agents,
particularly paraffin, nitrogen-containing corrosion inhibitor compounds and Mn(II)
compounds, particularly Mn(II) salts of organic ligands.
[0248] Organic silver coating agents are described in PCT Publication No. WO94/16047 and
copending European application No. EP-A-690122. Nitrogen-containing corrosion inhibitor
compounds are disclosed in copending European Application no. EP-A-634,478. Mn(II)
compounds for use in corrosion inhibition are described in copending European Application
No. EP-A-672 749.
[0249] Organic silver coating agent may be incorporated at a level of from 0.05% to 10%,
preferably from 0.1% to 5% by weight of the total composition.
[0250] The functional role of the silver coating agent is to form 'in use' a protective
coating layer on any silverware components of the washload to which the compositions
of the invention are being applied. The silver coating agent should hence have a high
affinity for attachment to solid silver surfaces, particularly when present in as
a component of an aqueous washing and bleaching solution with which the solid silver
surfaces are being treated.
[0251] Suitable organic silver coating agents herein include fatty esters of mono- or polyhydric
alcohols having from 1 to 40 carbon atoms in the hydrocarbon chain.
[0252] The fatty acid portion of the fatty ester can be obtained from mono- or polycarboxylic
acids having from 1 to 40 carbon atoms in the hydrocarbon chain. Suitable examples
of monocarboxylic fatty acids include behenic acid, stearic acid, oleic acid, palmitic
acid, myristic acid, lauric acid, acetic acid, propionic acid, butyric acid, isobutyric
acid, Valerie acid, lactic acid, glycolic acid and β,β'-dihydroxyisobutyric acid.
Examples of suitable polycarboxylic acids include: n-butyl-malonic acid, isocitric
acid, citric acid, maleic acid, malic acid and succinic acid.
[0253] The fatty alcohol radical in the fatty ester can be represented by mono- or polyhydric
alcohols having from 1 to 40 carbon atoms in the hydrocarbon chain. Examples of suitable
fatty alcohols include; behenyl, arachidyl, cocoyl, oleyl and lauryl alcohol, ethylene
glycol, glycerol, ethanol, isopropanol, vinyl alcohol, diglycerol, xylitol, sucrose,
erythritol, pentaerythritol, sorbitol or sorbitan.
[0254] Preferably, the fatty acid and/or fatty alcohol group of the fatty ester adjunct
material have from 1 to 24 carbon atoms in the alkyl chain.
[0255] Preferred fatty esters herein are ethylene glycol, glycerol and sorbitan esters wherein
the fatty acid portion of the ester normally comprises a species selected from behenic
acid, stearic acid, oleic acid, palmitic acid or myristic acid.
[0256] The glycerol esters are also highly preferred. These are the mono-, di- or tri-esters
of glycerol and the fatty acids as defined above.
[0257] Specific examples of fatty alcohol esters for use herein include: stearyl acetate,
palmityl di-lactate, cocoyl isobutyrate, oleyl maleate, oleyl dimaleate, and tallowyl
proprionate. Fatty acid esters useful herein include: xylitol monopalmitate, pentaerythritol
monostearate, sucrose monostearate, glycerol monostearate, ethylene glycol monostearate,
sorbitan esters. Suitable sorbitan esters include sorbitan monostearate, sorbitan
palmitate, sorbitan monolaurate, sorbitan monomyristate, sorbitan monobehenate, sorbitan
mono-oleate, sorbitan dilaurate, sorbitan distearate, sorbitan dibehenate, sorbitan
dioleate, and also mixed tallowalkyl sorbitan mono- and di-esters.
[0258] Glycerol monostearate, glycerol mono-oleate, glycerol monopalmitate, glycerol monobehenate,
and glycerol distearate are preferred glycerol esters herein.
[0259] Suitable organic silver coating agents include triglycerides, mono or diglycerides,
and wholly or partially hydrogenated derivatives thereof, and any mixtures thereof.
Suitable sources of fatty acid esters include vegetable and fish oils and animal fats.
Suitable vegetable oils include soy bean oil, cotton seed oil, castor oil, olive oil,
peanut oil, safflower oil, sunflower oil, rapeseed oil, grapeseed oil, palm oil and
corn oil.
[0260] Waxes, including microcrystalline waxes are suitable organic silver coating agents
herein. Preferred waxes have a melting point in the range from 35°C to 110°C and comprise
generally from 12 to 70 carbon atoms. Preferred are petroleum waxes of the paraffin
and microcrystalline type which are composed of long-chain saturated hydrocarbon compounds.
[0261] Alginates and gelatin are suitable organic silver coating agents herein.
[0262] Dialkyl amine oxides such as C
12-C
20 methylamine oxide, and dialkyl quaternary ammonium compounds and salts, such as the
C
12-C
20 methylammonium halides are also suitable.
[0263] Other suitable organic silver coating agents include certain polymeric materials.
Polyvinylpyrrolidones with an average molecular weight of from 12,000 to 700,000,
polyethylene glycols (PEG) with an average molecular weight of from 600 to 10,000,
polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole,
and cellulose derivatives such as methylcellulose, carboxymethylcellulose and hydroxyethylcellulose
are examples of such polymeric materials.
[0264] Certain perfume materials, particularly those demonstrating a high substantivity
for metallic surfaces, are also useful as the organic silver coating agents herein.
[0265] Polymeric soil release agents can also be used as an organic silver coating agent.
[0266] A preferred organic silver coating agent is a paraffin oil, typically a predominantly
branched aliphatic hydrocarbon having a number of carbon atoms in the range of from
20 to 50; preferred paraffin oil selected from predominantly branched C
25-45 species with a ratio of cyclic to noncyclic hydrocarbons of from 1:10 to 2:1, preferably
from 1:5 to 1:1. A paraffin oil meeting these characteristics, having a ratio of cyclic
to noncyclic hydrocarbons of 32:68, is sold by Wintershall, Salzbergen, Germany, under
the trade name WINOG 70.
Nitrogen-containing corrosion inhibitor compounds
[0267] Suitable nitrogen-containing corrosion inhibitor compounds include imidazole and
derivatives thereof such as benzimidazole, 2-heptadecyl imidazole and those imidazole
derivatives described in Czech Patent No. 139, 279 and British Patent GB-A-1,137,741,
which also discloses a method for making imidazole compounds.
[0268] Also suitable as nitrogen-containing corrosion inhibitor compounds are pyrazole compounds
and their derivatives, particularly those where the pyrazole is substituted in any
of the 1, 3, 4 or 5 positions by substituents R
1, R
3, R
4 and R
5 where R
1 is any of H, CH
2OH, CONH
3, or COCH
3, R
3 and R
5 are any of C
1-C
20 alkyl or hydroxyl, and R
4 is any of H, NH
2 or NO
2.
[0269] Other suitable nitrogen-containing corrosion inhibitor compounds include benzotriazole,
2-mercaptobenzothiazole, 1-phenyl-5-mercapto-1,2,3,4-tetrazole, thionalide, morpholine,
melamine, distearylamine, stearoyl stearamide, cyanuric acid, aminotriazole, aminotetrazole
and indazole.
[0270] Nitrogen-containing compounds such as amines, especially distearylamine and ammonium
compounds such as ammonium chloride, ammonium bromide, ammonium sulphate or diammonium
hydrogen citrate are also suitable.
Mn(II) corrosion inhibitor compounds
[0271] The detergent tablets may contain an Mn(II) corrosion inhibitor compound. The Mn(II)
compound is preferably incorporated at a level of from 0.005% to 5% by weight, more
preferably from 0.01% to 1%, most preferably from 0.02% to 0.4% by weight of the compositions.
Preferably, the Mn(II) compound is incorporated at a level to provide from 0.1 ppm
to 250 ppm, more preferably from 0.5 ppm to 50 ppm, most preferably from 1 ppm to
20 ppm by weight of Mn(II) ions in any bleaching solution.
[0272] The Mn (II) compound may be an inorganic salt in anhydrous, or any hydrated forms.
Suitable salts include manganese sulphate, manganese carbonate, manganese phosphate,
manganese nitrate, manganese acetate and manganese chloride. The Mn(II) compound may
be a salt or complex of an organic fatty acid such as manganese acetate or manganese
stearate.
[0273] The Mn(II) compound may be a salt or complex of an organic ligand. In one preferred
aspect the organic ligand is a heavy metal ion sequestrant. In another preferred aspect
the organic ligand is a crystal growth inhibitor.
Other corrosion inhibitor compounds
[0274] Other suitable additional corrosion inhibitor compounds include, mercaptans and diols,
especially mercaptans with 4 to 20 carbon atoms including lauryl mercaptan, thiophenol,
thionapthol, thionalide and thioanthranol. Also suitable are saturated or unsaturated
C
10-C
20 fatty acids, or their salts, especially aluminium tristearate. The C
12-C
20 hydroxy fatty acids, or their salts, are also suitable. Phosphonated octadecane and
other anti-oxidants such as betahydroxytoluene (BHT) are also suitable.
[0275] Copolymers of butadiene and maleic acid, particularly those supplied under the trade
reference no. 07787 by Polysciences Inc have been found to be of particular utility
as corrosion inhibitor compounds.
Hydrocarbon oils
[0276] Another preferred detergent component for use in the present invention is a hydrocarbon
oil, typically a predominantly long chain, aliphatic hydrocarbons having a number
of carbon atoms in the range of from 20 to 50; preferred hydrocarbons are saturated
and/or branched; preferred hydrocarbon oil selected from predominantly branched C
25-45 species with a ratio of cyclic to noncyclic hydrocarbons of from 1:10 to 2:1, preferably
from 1:5 to 1:1. A preferred hydrocarbon oil is paraffin. A paraffin oil meeting the
characteristics as outlined above, having a ratio of cyclic to noncyclic hydrocarbons
of 32:68, is sold by Wintershall, Salzbergen, Germany, under the trade name WINOG
70.
Water-soluble bismuth compound
[0277] The detergent tablets of the present invention suitable for use in dishwashing methods
may contain a water-soluble bismuth compound, preferably present at a level of from
0.005% to 20%, more preferably from 0.01% to 5%, most preferably from 0.1% to 1% by
weight of the compositions.
[0278] The water-soluble bismuth compound may be essentially any salt or complex of bismuth
with essentially any inorganic or organic counter anion. Preferred inorganic bismuth
salts are selected from the bismuth trihalides, bismuth nitrate and bismuth phosphate.
Bismuth acetate and citrate are preferred salts with an organic counter anion.
Enzyme Stabilizing System
[0279] Preferred enzyme-containing compositions herein may comprise from 0.001% to 10%,
preferably from 0.005% to 8%, most preferably from 0.01% to 6%, by weight of an enzyme
stabilizing system. The enzyme stabilizing system can be any stabilizing system which
is compatible with the detersive enzyme. Such stabilizing systems can comprise calcium
ion, boric acid, propylene glycol, short chain carboxylic acid, boronic acid, chlorine
bleach scavengers and mixtures thereof. Such stabilizing systems can also comprise
reversible enzyme inhibitors, such as reversible protease inhibitors.
Lime soap dispersant compound
[0280] The tablets of the present invention may contain a lime soap dispersant compound,
preferably present at a level of from 0.1% to 40% by weight, more preferably 1% to
20% by weight, most preferably from 2% to 10% by weight of the compositions.
[0281] A lime soap dispersant is a material that prevents the precipitation of alkali metal,
ammonium or amine salts of fatty acids by calcium or magnesium ions. Preferred lime
soap disperant compounds are disclosed in PCT Application No. WO93/08877.
Suds suppressing system
[0282] The detergent tablets of the present invention, when formulated for use in machine
washing compositions, preferably comprise a suds suppressing system present at a level
of from 0.01% to 15%, preferably from 0.05% to 10%, most preferably from 0.1% to 5%
by weight of the composition.
[0283] Suitable suds suppressing systems for use herein may comprise essentially any known
antifoam compound, including, for example silicone antifoam compounds, 2-alkyl and
alcanol antifoam compounds. Preferred suds suppressing systems and antifoam compounds
are disclosed in PCT Application No. WO93/08876 and EP-A-705 324.
Polymeric dye transfer inhibiting agents
[0284] The detergent tablets herein may also comprise from 0.01% to 10%, preferably from
0.05% to 0.5% by weight of polymeric dye transfer inhibiting agents.
[0285] The polymeric dye transfer inhibiting agents are preferably selected from polyamine
N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinylpyrrolidonepolymers
or combinations thereof.
Optical brightener
[0286] The detergent tablets suitable for use in laundry washing methods as described herein,
also optionally contain from 0.005% to 5% by weight of certain types of hydrophilic
optical brighteners.
[0287] Hydrophilic optical brighteners useful herein include those having the structural
formula:
wherein R
1 is selected from anilino, N-2-bis-hydroxyethyl and NH-2-hydroxyethyl; R
2 is selected from N-2-bis-hydroxyethyl, N-2-hydroxyethyl-N-methylamino, morphilino,
chloro and amino; and M is a salt-forming cation such as sodium or potassium.
[0288] When in the above formula, R
1 is anilino, R
2 is N-2-bis-hydroxyethyl and M is a cation such as sodium, the brightener is 4,4',-bis[(4-anilino-6-(N-2-bis-hydroxyethyl)-s-triazine-2-yl)amino]-2,2'-stilbenedisulfonic
acid and disodium salt. This particular brightener species is commercially marketed
under the tradename Tinopal-UNPA-GX by Ciba-Geigy Corporation. Tinopal-UNPA-GX is
the preferred hydrophilic optical brightener useful in the detergent compositions
herein.
[0289] When in the above formula, R
1 is anilino, R
2 is N-2-hydroxyethyl-N-2-methylamino and M is a cation such as sodium, the brightener
is 4,4'-bis[(4-anilino-6-(N-2-hydroxyethyl-N-methylamino)-s-triazine-2-yl)amino]2,2'-stilbenedisulfonic
acid disodium salt. This particular brightener species is commercially marketed under
the tradename Tinopal 5BM-GX by Ciba-Geigy Corporation.
[0290] When in the above formula, R
1 is anilino, R
2 is morphilino and M is a cation such as sodium, the brightener is 4,4'-bis[(4-anilino-6-morphilino-s-triazine-2-yl)amino]2,2'-stilbenedisulfonic
acid, sodium salt. This particular brightener species is commercially marketed under
the tradename Tinopal AMS-GX by Ciba Geigy Corporation.
Clay softening system
[0291] The detergent tablets suitable for use in laundry cleaning methods may contain a
clay softening system comprising a clay mineral compound and optionally a clay flocculating
agent.
[0292] The clay mineral compound is preferably a smectite clay compound. Smectite clays
are disclosed in the US Patents No.s 3,862,058, 3,948,790, 3,954,632 and 4,062,647.
European Patents No.s EP-A-299,575 and EP-A-313,146 in the name of the Procter and
Gamble Company describe suitable organic polymeric clay flocculating agents.
Cationic fabric softening agents
[0293] Cationic fabric softening agents can also be incorporated into compositions in accordance
with the present invention which are suitable for use in methods of laundry washing.
Suitable cationic fabric softening agents include the water insoluble tertiary amines
or dilong chain amide materials as disclosed in GB-A-1 514 276 and EP-B-0 011 340.
[0294] Cationic fabric softening agents are typically incorporated at total levels of from
0.5% to 15% by weight, normally from 1% to 5% by weight.
Other optional ingredients
[0295] Other optional ingredients suitable for inclusion in the compositions of the invention
include perfumes and filler salts, with sodium sulfate being a preferred filler salt.
pH of the compositions
[0296] The detergent tablets of the present invention are preferably not formulated to have
an unduly high pH, in preference having a pH measured as a 1% solution in distilled
water of from 8.0 to 12.5, more preferably from 9.0 to 11.8, most preferably from
9.5 to 11.5.
Machine dishwashing method
[0297] Any suitable methods for machine washing or cleaning soiled tableware are envisaged.
[0298] A preferred machine dishwashing method comprises treating soiled articles selected
from crockery, glassware, silverware, metallic items, cutlery and mixtures thereof,
with an aqueous liquid having dissolved or dispensed therein an effective amount ofa
detergent tablet in accord with the invention. By an effective amount of the detergent
tablet it is meant from 8g to 60g of product dissolved or dispersed in a wash solution
of volume from 3 to 10 litres, as are typical product dosages and wash solution volumes
commonly employed in conventional machine dishwashing methods. Preferably the detergent
tablets are from 15g to 40g in weight, more preferably from 20g to 35g in weight.
Laundry washing method
[0299] Machine laundry methods herein typically comprise treating soiled laundry with an
aqueous wash solution in a washing machine having dissolved or dispensed therein an
effective amount of a machine laundry detergent tablet composition in accord with
the invention. By an effective amount of the detergent tablet composition it is meant
from 40g to 300g of product dissolved or dispersed in a wash solution of volume from
5 to 65 litres, as are typical product dosages and wash solution volumes commonly
employed in conventional machine laundry methods.
[0300] In a preferred use aspect a dispensing device is employed in the washing method.
The dispensing device is charged with the detergent product, and is used to introduce
the product directly into the drum of the washing machine before the commencement
of the wash cycle. Its volume capacity should be such as to be able to contain sufficient
detergent product as would normally be used in the washing method.
[0301] Once the washing machine has been loaded with laundry the dispensing device containing
the detergent product is placed inside the drum. At the commencement of the wash cycle
of the washing machine water is introduced into the drum and the drum periodically
rotates. The design of the dispensing device should be such that it permits containment
of the dry detergent product but then allows release of this product during the wash
cycle in response to its agitation as the drum rotates and also as a result of its
contact with the wash water.
[0302] To allow for release of the detergent product during the wash the device may possess
a number of openings through which the product may pass. Alternatively, the device
may be made of a material which is permeable to liquid but impermeable to the solid
product, which will allow release of dissolved product. Preferably, the detergent
product will be rapidly released at the start of the wash cycle thereby providing
transient localised high concentrations of product in the drum of the washing machine
at this stage of the wash cycle.
[0303] Preferred dispensing devices are reusable and are designed in such a way that container
integrity is maintained in both the dry state and during the wash cycle.
[0304] Alternatively, the dispensing device may be a flexible container, such as a bag or
pouch. The bag may be of fibrous construction coated with a water impermeable protective
material so as to retain the contents, such as is disclosed in European published
Patent Application No. 0018678. Alternatively it may be formed of a water-insoluble
synthetic polymeric material provided with an edge seal or closure designed to rupture
in aqueous media as disclosed in European published Patent Application Nos. 0011500,
0011501, 0011502, and 0011968. A convenient form of water frangible closure comprises
a water soluble adhesive disposed along and sealing one edge of a pouch formed of
a water impermeable polymeric film such as polyethylene or polypropylene.
Examples
Abbreviations used in Examples
[0305] In the detergent compositions, the abbreviated component identifications have the
following meanings:
STPP |
Sodium tripolyphosphate |
Bicarbonate |
Sodium hydrogen carbonate |
Citric Acid |
Anhydrous Citric acid |
Carbonate |
Anhydrous sodium carbonate |
Silicate |
Amorphous Sodium Silicate (SiO2:Na2O ratio = 2.0) |
SKS-6 |
Crystalline layered silicate of formula δ-Na2Si2O5 |
PB1 |
Anhydrous sodium perborate monohydrate |
Nonionic |
C13-C15 mixed ethoxylated/propoxylated fatty alcohol with an average degree of ethoxylation
of 3.8 and an average degree of propoxylation of 4.5, sold under the tradename Plurafac
by BASF |
TAED |
Tetraacetyl ethylene diamine |
HEDP |
Ethane 1-hydroxy-1,1-diphosphonic acid |
PAAC |
Pentaamine acetate cobalt (III) salt |
Paraffin |
Paraffin oil sold under the tradename Winog 70 by Wintershall. |
Protease |
Proteolytic enzyme |
Amylase |
Amylolytic enzyme. |
BTA |
Benzotriazole |
Sulphate |
Anhydrous sodium sulphate. |
PEG 3000 |
Polyethylene Glycol molecular weight approximately 3000 available from Hoechst |
PEG 6000 |
Polyethylene Glycol molecular weight approximately 6000 available from Hoechst |
pH |
Measured as a 1% solution in distilled water at 20°C |
[0306] In the following examples all levels are quoted as parts by weight:
Examples I-IV
[0307] The following illustrates examples detergent tablets of the present invention suitable
for use in a dishwashing machine.
|
I |
II |
III |
IV |
V |
VI |
Phase 1 |
|
|
|
|
|
|
STPP |
9.62 |
9.62 |
10.45 |
9.57 |
9.57 |
11.47 |
Silicate |
0.50 |
0.67 |
1.60 |
1.00 |
1.00 |
2.40 |
SKS-6 |
1.5 |
1.50 |
|
2.30 |
2.25 |
|
Carbonate |
2.33 |
2.74 |
3.5 |
3.59 |
4.10 |
5.25 |
HEDP |
0.18 |
0.18 |
0.18 |
0.28 |
0.28 |
0.28 |
PB1 |
2.45 |
2.45 |
2.45 |
3.68 |
3.68 |
3.68 |
PAAC |
0.002 |
0.002 |
0.002 |
0.003 |
0.004 |
0.004 |
Amylase |
0.148 |
0.110 |
0.110 |
0.252 |
0.163 |
0.163 |
Protease |
0.06 |
0.06 |
0.06 |
0.09 |
0.09 |
0.09 |
Nonionic |
0.40 |
0.80 |
0.80 |
1.20 |
1.20 |
1.20 |
PEG 6000 |
0.4 |
0.26 |
0.26 |
0.38 |
0.39 |
0.39 |
BTA |
0.04 |
0.04 |
0.04 |
|
0.06 |
0.06 |
Paraffin |
0.10 |
0.10 |
0.10 |
0.15 |
0.15 |
0.15 |
Perfume |
0.02 |
0.02 |
0.02 |
0.013 |
0.013 |
0.013 |
Sulphate |
|
|
|
0.502 |
0.05 |
2.843 |
Total |
17.75g |
18.55g |
19.57g |
23.0g |
23.0g |
23.0g |
Phase 2 |
|
|
|
|
|
|
Amylase |
0.30 |
0.35 |
0.25 |
0.30 |
0.35 |
0.25 |
Protease |
0.25 |
0.22 |
0.30 |
0.25 |
0.22 |
0.30 |
Citric acid |
0.3 |
|
0.30 |
0.3 |
|
0.30 |
Sulphamic acid |
|
0.3 |
|
|
0.3 |
|
Bicarbonate |
1.09 |
0.45 |
0.45 |
1.09 |
0.45 |
0.45 |
Carbonate |
|
0.55 |
|
|
0.55 |
|
Silicate |
|
|
0.64 |
|
|
0.64 |
CaCl2 |
|
0.07 |
|
|
0.07 |
|
PEG 3000 |
0.06 |
0.06 |
0.06 |
0.06 |
0.06 |
0.06 |
Total |
2.0g |
2.0g |
2.0g |
2.0g |
2.0g |
2.0g |
[0308] The multi-phase tablet compositions are prepared as follows. The detergent active
composition of phase 1 is prepared by admixing the granular and liquid components
and is then passed into the die of a conventional rotary press. The press includes
a punch suitably shaped for forming the mould. The cross-section of the die is approximately
30x38 mm. The composition is then subjected to to a compression force of 940 kg/cm
2 and the punch is then elevated exposing the first phase of the tablet containing
the mould in its upper surface. The detergent active composition of phase 2 is prepared
in similar manner and is passed into the die. The particulate active composition is
then subjected to a compression force of 170 kg/cm
2, the punch is elevated, and the multi-phase tablet ejected from the tablet press.
The resulting tablets dissolve or disintegrate in a washing machine as described above
within 12 minutes, phase 2 of the tablets dissolving within 5 minutes. The tablets
provide excellent dissolution and cleaning characteristics together with good tablet
integrity and strength.