Technical field
[0001] The present invention relates to the field of detergency, especially laundry detergents.
Ingredients commonly used in laundry detergents, especially bleach activators, are
formed into particles using secondary (2,3) alkyl sulfate surfactants as an agglomerating
agent. The resulting particles exhibit improved bleaching performance in aqueous laundering
operations.
Background of the invention
[0002] Many fully-formulated laundry detergents provide both cleaning and bleaching benefits
in a single product. Accordingly, such products will typically comprise one or more
detersive surfactants, various builders, one or more types of detersive enzymes, chelants,
soil release polymers, and the like, together with effective bleaching agents such
as perborate, percarbonate or persulfate compounds. The objective of the detergent
formulator is to use ingredients of a type and in the proper proportions that will
safely and effectively remove a variety of soils and stains from a variety of fabrics
under widely disparate laundering conditions, ranging from cold water to boil washes.
As is well known, bleaching agents such as those noted above do not function optimally
at washing temperatures below about 60°C. However, many users of laundry detergent
compositions now prefer to launder fabrics at somewhat cooler temperatures, both to
save energy and to help maintain fabric appearance. Accordingly, conventional bleach-assisted
detergents do not provide optimal cleaning benefits to such cool-water users. In a
successful attempt to improve cool water bleaching performance, formulators have added
the so-called "bleach activators" to laundry detergent compositions. Such activators
co-act with bleaching agents such as perborate, percarbonate and the like, by a perhydrolysis
mechanism to provide active bleaching species in the aqueous laundry liquor even at
cool water temperatures. Bleach activators such as tetraacetylethylene diamine ("TAED"),
nonanoyloxybenzene sulfonate ("NOBS") and mixtures thereof, are well-known bleach
activators in commercial practice. Unfortunately, many bleach activators such as TAED
are solids which are relatively insoluble in aqueous wash liquors during the time
span of a typical laundering operation. Hence, the effectiveness of such insoluble
bleach activators would be substantially decreased if means were not found to enhance
their dispersion in aqueous wash liquors and, correspondingly, their rate of perhydrolysis.
Moreover, unsolubilized particles of such activators can deposit onto fabrics from
the wash liquor and cause "pin-point" color damage. Merely decreasing the particle
size of such solid bleach activators to improve their dispersion is impractical, since
extremely small particles tend to be unstable in finished products.
[0003] Accordingly a need exists to provide detergent compositions in which the bleach activator
is incorporated in a form that minimizes and preferably eliminates damage to fabric
colours and materials while enhancing the dispersion in aqueous wash liquors and rate
of perhydrolysis of said bleach activators.
[0004] The prior art contains numerous examples of bleach activators coated or agglomerated
so as to increase their stability on storage in detergent compositions and/or to influence
their solution behaviour. Various patents disclose the coating of bleach activators
with fatty acids (see for instance GB-A-1507312 or GB-A-1381121). EP-A-0375241 describes
stabilized bleach activator extrudates in which C₅- C₁₈ alkyl peroxy carboxylic acid
precursors are mixed with a binder selected from anionic and nonionic surfactants,
film forming polymers fatty acids or mixtures of such binders. Furthermore, detergent
formulators who wish to use relatively insoluble materials such as the TAED bleach
activators have also learned to agglomerate particles of said materials with nonionic
surfactants, especially the highly ethoxylated alcohols such as ethoxylated (EO25)
tallow alcohol. Where coating and/or agglomeration has been proposed with poorly soluble
materials such as fatty acids or with nonionic surfactants such as EO25, this has
resulted in a rate of perhydrolysis of the bleach activator which is slower than that
which would occur if it had not been so protected. Accordingly, improved means for
enhancing the performance of bleach activators is of substantial importance in this
field. It is thus an object of the present invention to provide a solid bleach activator
composition comprising a particulate bleach activator material with a significantly
increased rate of perhydrolysis, thereby increasing the effectiveness of the resultant
bleach.
[0005] Another problem encountered with the compositions of the prior art relates to the
storage and handling properties of said compositions, and it is thus an additional
object of the present invention to provide a bleach activator composition as a free-flowable
powder which remains as such throughout prolonged storage time.
[0006] The applicant has now surprisingly found that surfactants which comprise the class
of secondary (2,3) alkyl sulfates provide superior means for agglomerating detersive
ingredients such as TAED bleach activators and further coating said agglomerated detersive
ingredients. The particulate bleach activator materials obtained accordingly allow
to enhance the dispersion in aqueous wash liquors of said activators as well as to
improve their rate of perhydrolysis as compared to activators-plus-nonionic agglomerating
agents, noted above, this without requiring a decreased particle size. Furthermore,
solid bleach activator compositions comprising said particulate bleach activator materials
result in storage-stable free-flowable powders. Moreover, the secondary (2,3) alkyl
sulfates are calcium-insensitive and are thus useful in underbuilt compositions, including
nil-phosphate compositions. The secondary (2,3) alkyl sulfates are solids, and can
be used in the molten state to quickly and easily agglomerate powders such as TAED
with less moisture/solvents than other anionic surfactants. Moreover, the secondary
(2,3) alkyl sulfates are degradable both aerobically and anaerobically, which assists
in their disposal in the environment.
[0007] The satisfactorily perhydrolysis rate and dispersion properties associated to the
use of a solid bleach activator composition comprising the present particulate bleach
activator materials wherein the secondary (2,3) alkyl sulfates are used as an agglomerating
agent and optionally as an coating agent are unexpected and beneficial as said secondary
(2,3) alkyl sulfates are only known in the art context of laundry compositions as
surfactants, see for instance the following patents; US. 2,900,346, Fowkes et al,
August 18, 1959; U.S. 3,468,805, Grifo et al, September 23, 1969; U.S. 3,480,556,
DeWitt et al, November 25, 1969; U.S. 3,681,424, Bloch et al, August 1, 1972; U.S.
4,052,342, Fernley et al, October 4, 1977; U.S. 4,079,020, Mills et al, March 14,
1978; U.S. 4,235,752, Rossall et al, November 25, 1980; U.S. 4,529,541, Wilms et al,
July 16, 1985; U.S. 4,614,612, Reilly et al, September 30, 1986; U.S. 4,880,569, Leng
et al, November 14, 1989; U.S. 5,075,041, Lutz, December 24, 1991; U.K. 818,367, Bataafsche
Petroleum, August 12, 1959; U.K. 1,585,030, Shell, February 18, 1981; GB 2,179,054A,
Leng et al, February 25, 1987 (referring to GB 2,155,031).
Summary of the Invention
[0008] The present invention is directed to a solid bleach activator composition comprising
a particulate bleach activator material wherein said activator is co-agglomerated
with an agglomerating agent, characterized in that said agglomerating agent is selected
from the group of secondary (2,3) alkyl sulfate surfactants.
[0009] The present invention also encompasses a solid bleach activator composition comprising
a co-agglomerated particulate bleach activator material as previously defined which
is further coated with a coating agent. Said coating agent may be selected from the
group of secondary (2,3) alkyl sulfate surfactants or any others coating agents well
known in the art.
[0010] The present invention further encompasses process for manufacturing the particulate
bleach activator materials according to the present invention.
Detailed description of the invention
[0011] The solid bleach activator compositions of the present invention comprise particulate
bleach activator materials wherein said activator is co-agglomerated with a secondary
(2,3) alkyl sulfate surfactant.
[0012] As a first essential ingredient the compositions of the present invention contain
a bleach activator, or mixtures thereof. Said bleach activator leads to the in situ
production in aqueous solution (i.e., during the washing process) of the peroxy acid
corresponding to said bleach activator. Said bleach activators used herein can be
any of the bleach activators useful for detergent compositions in textile cleaning,
hard surface cleaning or other cleaning purposes that are now known or become known.
Various nonlimiting examples of activators are disclosed in U.S. Patent US-4 915 854
and in U.S. Patent US-4 412 934. For instance bleach activators particularly suitable
to be used in the present invention contain one or more N- or O- acyl groups, said
activators can be selected from a wide range of classes. Suitable classes include
anhydrides, esters, imides and acylated derivatives of imidazoles and oximes, and
examples of useful materials within these classes are disclosed in GB-A-1586789. The
most preferred classes are esters such as are disclosed in GB-A-836988, 864,798, 1147871
and 2143231 and imides such as are disclosed in GB-A-855735 & 1246338.
[0013] Particularly preferred bleach activators are the N-,N,N¹N¹ tetra acetylated compounds
of formula

wherein x can be O or an integer between 1 & 6.
[0014] Examples include tetra acetyl methylene diamine (TAMD) in which x=1, tetra acetyl
ethylene diamine (TAED) in which x=2 and tetraacetyl hexylene diamine (TAHD) in which
x=6. These and analogous compounds are described in GB-A-907356. The most preferred
peroxyacid bleach activator is TAED.
[0015] Said solid peroxyacid bleach activators useful in the present invention have a Mpt>30°C
and preferably >40°C. Such activators will normally be in fine powder or crystalline
form in which at least 90% by weight of the powder has a particle size < 150 micrometers.
[0016] Other particularly suitable bleach activators to be used in the present invention
are nonanoyloxybenzene sulfonate (NOBS), isononanoyloxybenzene sulfonate (isoNOBS),
benzoyloxybenzene sulfonate (BOBS), benzoxazin-type activators, peroxyacid activators
having amide moieties and/or caprolactam derivatives. Also particularly preferred
are N-acyl caprolactam selected form the group consisting of substituted or unsubstituted
benzoyl caprolactam, octanyl caprolactam, nonanoyl caprolactam, hexanoyl caprolactam,
decanoyl caprolactam, undecenoyl caprolactam, formyl caprolactam, acetyl caprolactam,
propanoyl caprolactam, butanoyl caprolactam pentanoyl caprolactam. These and analogous
compounds are described in the co-pending US patent applications 08064623, 08064627,
08064562, 08064564, 08064624 and 08064563 and US patent US-4 634 551.
[0017] Another essential ingredient of the compositions according to the present invention
is a secondary (2,3) alkyl sulfate surfactant. Said secondary (2,3) alkyl sulfate
surfactant is used in the compositions according to the present invention as an agglomerating
agent to co-agglomerate said bleach activator. In another embodiment of the present
invention said secondary (2,3) alkyl sulfate surfactant may also be used as a coating
agent to coat said co-agglomerate bleach activator.
[0018] For the convenience of the formulator, the following identifies and illustrates the
differences between the sulfated surfactants employed herein as an agglomerating and/or
coating agent and otherwise conventional alkyl sulfate surfactants.
[0019] Conventional primary alkyl sulfate surfactants have the general formula
ROSO3-M+
wherein R is typically a linear C10-C20 hydrocarbyl group and M is a water-solubilizing
cation. Branched-chain primary alkyl sulfate surfactants (i.e., branched-chain "PAS")
having 10-20 carbon atoms are also known; see, for example, European Patent Application
EP-439 316.
Conventional secondary alkyl sulfate surfactants are those materials which have
the sulfate moiety distributed randomly along the hydrocarbone "backbone" of the molecule.
Such materials may be depicted by the structure
CH3(CH2)n(CHOSO3-M+)(CH2)mCH3
wherein m and n are integers of 2 or greater and the sum of m + n is typically 9 to
15, and M is a water-solubilizing cation.
By contrast with the above, the selected secondary (2,3) alkyl sulfate surfactants
used herein comprise structures of formulas A and B
(A) CH3(CH2)x(CHOSO3-M+) CH3 and
(B) CH3(CH2)y(CHOSO3-M+) CH2CH3
for the 2-sulfate and 3-sulfate, respectively. Mixtures of the 2- and 3-sulfate can
be used herein. In formulas A and B, x and (y-1) are, respectively, integers of at
least 6, and can range from 7 to 20, preferably 10 to 16. M is a cation, such as an
alkali metal, ammonium, alkanolammonium, alkaline earth metal, or the like. Sodium
is typical for use as M to prepare the water-soluble (2,3) alkyl sulfates, but ethanolammonium,
diethanolammonium, triethanolammonium, potassium, ammonium, and the like, can also
be used.
[0020] By the present invention it has been determined that the physical/chemical properties
of the foregoing types of alkyl sulfate surfactants are unexpectedly different, one
from another, in several aspects which are important to formulators of various types
of detergent compositions. For example, the primary alkyl sulfates can disadvantageously
interact with, and even be precipitated by, metal cations such as calcium and magnesium.
Thus, water hardness can negatively affect the primary alkyl sulfates to a greater
extent than the secondary (2,3) alkyl sulfates herein. Accordingly, the secondary
(2,3) alkyl sulfates have now been found to be preferred for use in the presence of
calcium ions and under conditions of high water hardness, or in the so-called "under-built"
situation which can occur with nonphosphate builders.
[0021] Importantly, when formulating concentrated liquid detergents with calcium or magnesium
ions to enhance grease cutting or sudsing performance it has now been found that the
primary alkyl sulfates can be problematic due to such interactions with calcium or
magnesium cations. Moreover, the solubility of the primary alkyl sulfates is not as
great as the secondary (2,3) alkyl sulfates. Hence, the formulation of high-active
liquid and gel detergents has now been found to be simpler and more effective with
the secondary (2,3) alkyl sulfates than with the primary alkyl sulfates.
With regard to the random secondary alkyl sulfates (i.e., secondary alkyl sulfates
with the sulfate group at positions such as the 4, 5, 6, 7, and the like secondary
carbon atoms), such materials tend to be tacky solids or pastes, and thus do not afford
the processing advantages associated with the secondary (2,3) alkyl sulfates when
formulating detergent bars, granules or tablets.
One additional advantage of the secondary (2,3) alkyl sulfate surfactants herein
over other positional or "random" alkyl sulfate isomers is in regard to the improved
benefits afforded by said secondary (2,3) alkyl sulfates with respect to soil redeposition
in the context of fabric laundering operations. As is well-known to users, laundry
detergents loosen soils from fabrics being washed and suspend the soils in the aqueous
laundry liquor. However, as is well-known to detergent formulators, some portion of
the suspended soil can be redeposited back onto the fabrics. Thus, some redistribution
and redeposition of the soil onto all fabrics in the load being washed can occur.
This, of course, is undesirable and can lead to the phenomenon known as fabric "greying".
(As a simple test of the redeposition characteristics of any given laundry detergent
formulation, unsoiled white "tracer" cloths can be included with the soiled fabrics
being laundered. At the end of the laundering operation the extent that the white
tracers deviate from their initial degree of whiteness can be measured photometrically
or estimated visually by skilled observers. The more the tracers' whiteness is retained,
the less soil redeposition has occurred.)
It has now been determined that the secondary (2,3) alkyl sulfates afford substantial
advantages in soil redeposition characteristics over the other positional isomers
of secondary alkyl sulfates in laundry detergents, as measured by the cloth tracer
method noted above. Thus, the selection of secondary (2,3) alkyl sulfate surfactants
according to the practice of this invention which preferably are substantially free
of other positional secondary isomers unexpectedly assist in solving the problem of
soil redeposition in a manner not heretofore recognized. It is to be noted that the
secondary (2,3) alkyl sulfates used herein are quite different in several important
properties from the secondary olefin sulfonates (e.g., US-4 064 076); accordingly,
the secondary sulfonates are not the focus of the present invention.
The preparation of the secondary (2,3) alkyl sulfates of the type useful herein
can be carried out by the addition of H2SO4 to olefins. A typical synthesis using
a-olefins and sulfuric acid is disclosed in the U.S. patents US-3 234 258 or US-5
075 041. The synthesis, conducted in solvents which afford the secondary (2,3) alkyl
sulfates on cooling, yields products which, when purified to remove the corresponding
sulfated nonionics, randomly sulfated materials, unsulfated by-products such as C10
and higher alcohols, secondary olefin sulfonates, and the like, are typically 90+%
pure mixtures of 2- and 3-sulfated materials (some sodium sulfate may be present)
and are white, non-tacky, apparently crystalline, solids. Some 2,3-disulfates may
also be present, but generally comprise no more than 5% of the mixture of secondary
(2,3) alkyl mono-sulfates. Such materials are available as under the name "DAN", e.g.,
"DAN 200" from Shell Oil Company.
If increased solubility or lower melting temperatures of the "crystalline" secondary
(2,3) alkyl sulfate surfactants is desired, the formulator may wish to employ mixtures
of such surfactants having a mixture of alkyl chain lengths. Thus, a mixture of C12-C18
alkyl chains will provide an increase in solubility over a secondary (2,3) alkyl sulfate
wherein the alkyl chain is, say, entirely C16. The solubility of the secondary (2,3)
alkyl sulfates can also be enhanced by the addition thereto of other surfactants such
as the alkyl ethoxylates or other nonionic surfactants, or by any other material which
decreases the crystallinity of the secondary (2,3) alkyl sulfates. Such crystallinity-interrupting
materials are typically effective at levels of 20%, or less, of the secondary (2,3)
alkyl sulfate.
When formulating liquid and gel compositions, especially clear liquids, it is preferred
that the secondary (2,3) alkyl sulfates contain less than 3% sodium sulfate, preferably
less than 1% sodium sulfate. In and of itself, sodium sulfate is an innocuous material.
However, it dissolves and adds to the ionic "load" in aqueous media, and this can
contribute to phase separation in liquid compositions and to gel breaking in the gel
compositions. Various means can be used to lower the sodium sulfate content of the
secondary (2,3) alkyl sulfates. For example, when the H2SO4 addition to the olefin
is completed, care can be taken to remove unreacted H2SO4 before the acid form of
the secondary (2,3) alkyl sulfate is neutralized. In another method, the sodium salt
form of the secondary (2,3) alkyl sulfate which contains sodium sulfate can be rinsed
with water at a temperature near or below the Krafft temperature of the sodium secondary
(2,3) alkyl sulfate. This will remove Na2SO4 with only minimal loss of the desired,
purified sodium secondary (2,3) alkyl sulfate. Of course, both procedures can be used,
the first as a pre-neutralization step and the second as a post-neutralization step.
The term "Krafft temperature" as used herein is a term of art which is well-known
to workers in the field of surfactant sciences. Krafft temperature is described by
K. Shinoda in the text "Principles of Solution and solubility", translation in collaboration
with Paul Becher, published by Marcel Dekker, Inc. 1978 at pages 160-161. Stated succinctly,
the solubility of a surface active agent in water increases rather slowly with temperature
up to that point, i.e., the Krafft temperature, at which the solubility evidences
an extremely rapid rise. At a temperature approximately 4°C above the Krafft temperature
a solution of almost any composition becomes a homogeneous phase. In general, the
Krafft temperature of any given type of surfactant, such as the secondary (2,3) alkyl
sulfates herein which comprise an anionic hydrophilic sulfate group and a hydrophobic
hydrocarbyl group, will vary with the chain length of the hydrocarbyl group. This
is due to the change in water solubility with the variation in the hydrophobic portion
of the surfactant molecule.
In the practice of the present invention the formulator may optionally wash the
secondary (2,3) alkyl sulfate surfactant which is contaminated with sodium sulfate
with water at a temperature that is no higher than the Krafft temperature, and which
is preferably lower than the Krafft temperature, for the particular secondary (2,3)
alkyl sulfate being washed. This allows the sodium sulfate to be dissolved and removed
with the wash water, while keeping losses of the secondary (2,3) alkyl sulfate into
the wash water to a minimum.
Under circumstances where the secondary (2,3) alkyl sulfate surfactant herein comprises
a mixture of alkyl chain lengths, it will be appreciated that the Krafft temperature
will not be a single point but, rather, will be denoted as a "Krafft boundary". Such
matters are well-known to those skilled in the science of surfactant/solution measurements.
In any event, for such mixtures of secondary (2,3) alkyl sulfates, it is preferred
to conduct the optional sodium sulfate removal operation at a temperature which is
below the Krafft boundary, and preferably below the Krafft temperature of the shortest
chain-length surfactant present in such mixtures, since this avoids excessive losses
of secondary (2,3) alkyl sulfate to the wash solution. For example, for C16 secondary
sodium alkyl (2,3) sulfate surfactants, it is preferred to conduct the washing operation
at temperatures below 30°C, preferably secondary (2,3) alkyl sulfates below 20°C.
It will be appreciated that changes in the cation will change the preferred temperature
for washing the secondary (2,3) alkyl sulfates, due to changes in the Krafft temperature.
The washing process can be conducted batchwise by suspending wet or dry secondary
(2,3) alkyl sulfates in sufficient water to provide 10-50% solids, typically for a
mixing time of at least 10 minutes at 22°C (for a C16 secondary (2,3) alkyl sulfate),
followed by pressure filtration. In a preferred mode, the slurry secondary (2,3) alkyl
sulfates will comprise somewhat less than 35% solids, inasmuch as such slurries are
free-flowing and amenable to agitation during the washing process.
As an additional benefit, the washing process also reduces the levels of organic
contaminants which comprise the random secondary alkyl sulfates noted above.
[0022] The present invention encompasses a process for manufacturing a particulate bleach
activator material according to the present invention, said process includes the steps
of:
- co-agglomerating a bleach activator with a secondary (2,3) alkyl sulfate surfactant
as the agglomerating agent;
- drying said co-agglomerate.
[0023] Any agglomerating technique known to the man skilled in the art is suitable for use
herein. For example, particulate materials can be formed by agglomeration, wherein
solids (including the secondary (2,3) alkyl sulfates) are forced/hurled together by
physical mixing and held together by a binder. Suitable apparatus for agglomeration
includes dry powder mixers, fluid beds and turbilizers, available from manufacturers
such as Lodge, Eric, Bepex and Aeromatic.
In another mode, particulate materials can be formed by extrusion. In this method,
solids (including the secondary (2,3) alkyl sulfates) are forced together by pumping
a damp powder at relatively high pressures and high energy inputs through small holes
in a die plate. This process results in rod like particles which can be divided into
any desired particle size. Apparatus includes axial or radial extruders such as those
available from Fuji, Bepex and Teledyne/Readco.
In yet another mode, particulate materials can be formed by prilling. In this method,
a liquid mixture containing the desired ingredients (i.e., one of them being secondary
(2,3) alkyl sulfates) is pumped under high pressure and sprayed into cool air. As
the liquid droplets cool they become more solid and thus the particulate materials
are formed. The solidification can occur due to the phase change of a molten binder
to a solid or through hydration of free moisture into crystalline bound moisture by
some hydratable material in the original liquid mixture.
In still another mode, particulate materials can be formed by compaction. This
method is similar to tablet formation processes, wherein solids (including secondary
(2,3) alkyl sulfates) are forced together by compressing the powder feed into a die/mold
on rollers or flat sheets.
In another mode, particulate materials can be formed by melt/solidification. In
this method, particulate materials are formed by melting the secondary (2,3) alkyl
sulfates with any desired additional ingredient such as TAED and allowing the melt
to cool, e.g., in a mold or as droplets.
Binders can optionally be used in the foregoing methods to enhance particle integrity
and strength. Such binders include, for example, starches, polyacrylates, carboxymethylcellulose
and the like. Binders are well-known in the particle making literature. If used, binders
are typically employed at levels of 0.1%-5% by weight of the finished particulate
materials.
Fillers such as hydratable and nonhydratable salts, crystalline and glassy solids,
various detersive ingredients such as zeolites and the like, can be incorporated in
the particulate materials. If used, such fillers typically comprise up to 20% by weight
of the particulate materials.
[0024] Chelants can be incorporated in the particle during the agglomeration process. Such
chelants include, for example, diethylene triamine penta methyl phosphonates or hydroxy
ethyl diphosphonic acid, or ethylene diamino disuccinic acid and the like. If used,
chelants are typically employed at levels of from 0.1% to 9% by weight of the finished
particulate materials, preferably of from 0.1% to 5% and more preferebly from 0.5%
to 2%.
Particulate materials prepared in the foregoing manner can be subsequently dried
or cooled to adjust their strength, physical properties and final moisture content,
according to the desires of the formulator.
One mode for preparing particulate materials comprising either solely secondary
(2,3) alkyl sulfates or mixtures thereof together with the co-surfactants comprises
mixing molten secondary (2,3) alkyl sulfates with one or more molten co-surfactants
and forming the resulting solidified melt into particles, prills or agglomerates of
any desired size. The desired particle size can be achieved, for example, in blenders,
such as that marketed under the trademark OSTER or in large-scale mills, such as that
available under the trademark WILEY mill.
In an alternate mode, the melt comprising the mixed surfactant can be sprayed through
a nozzle to form droplets which, when cooled, provide particles of the desired size.
In another mode, a rotating disc can be used to form droplets of a melt comprising
the secondary (2,3) alkyl sulfate and any desired co-surfactants. The droplets are
then solidified by cooling and may be passed through appropriate sieves to secure
particulate materials of any desired size. In yet another mode, tower prilling can
be used to provide particulate materials having a distribution of sizes around a given
mean size range.
In yet another mode, a homogeneous melt of the secondary (2,3) alkyl sulfates plus
co-surfactants is solidified and comminuted to provide particulate materials. High
energy comminution processes such as hammer, rod and ball mills can be used. In a
different mode, low energy comminution processes such as grating through sieves of
any desired pore size can be employed.
The present invention also encompasses a process for manufacturing a particulate
bleach activator material according to the present invention, said process including
the steps of:
- co-agglomerating a bleach activator with a secondary (2,3) alkyl sulfate surfactant
as the agglomerating agent;
- optionally drying said co-agglomerate;
- coating said dried co-agglomerate with a coating material as hereinbefore defined;
- drying said coated co-agglomerate.
[0025] According to the present invention the co-agglomerated bleach activator as hereinbefore
described can be coated with either a secondary (2,3) alkyl sulfate surfactant coating
agent as hereinbefore defined or with any others coating agents well known in the
art. Such coating agents include for instance soluble polymers (i.e. polyacrylates
or copolymers of acrylic/maleic units) or low molecular weight polycarboxylic acids
(citric acid) or glycolic acid.
[0026] The coating of the co-agglomerated material with the coating agent can be carried
out in several ways. The coating agent may be sprayed on as a molten material or as
a solution or dispersion in a solvent/carrier liquid which is subsequently removed
by evaporation. The coating agent can also be applied as a powder coating e.g. by
electrostatic techniques although this is less preferred as the adherence of powdered
coating agent is more difficult to achieve and can be more expensive.
[0027] When used as the bulk surfactant ingredient in the detergent compositions herein,
the particles ("base granules") will typically range in size from 50 to 2000 micrometers,
preferably from 150 to 2000 micrometers. When used to coat larger particles comprising
surfactant, the secondary alkyl sulfate coating particles will typically be in a substantially
finer size range, typically from 0.01 to 5 micrometers. In any event, size ranges
herein can be established using standard sieves. A sieve size in the range of 425
to 2000 micrometers is typical for base granules. A sieve size in the range of 0.05
to 1 micrometer is typical for coating particles.
[0028] The solid bleach activator compositions according to the present invention comprise
at least 30 % by weight of the total composition of said bleach activator, preferably
at least 50% and most preferably at least 70 %, and from 2 % to 60 % by weight of
the total composition of said secondary (2,3) alkyl sulfate, preferably from 4 % to
40 % and most preferably from 4 % to 20 %.
[0029] Solid bleach activator compositions in accordance with the invention can be used
in a variety of applications. Thus said solid bleach activator compositions according
to the present invention may themselves be incorporated into other solid compositions
such as tablets, extrudates and agglomerates. The compositions can also be suspended
in non aqueous liquid compositions in which the organic acid surface treating material
is insoluble and inert. However, the preferred application for the solid bleach activator
compositions of the invention is as particulate components of granular detergent compositions,
particularly the so-called concentrated detergent compositions that are added to a
washing machine by means of a dosing device placed in the machine drum with the soiled
fabric load. Concentrated granular detergent compositions dispensed into the wash
liquor via a dosing device are more subject to dissolution problems than compositions
added via the dispensing compartment of a washing machine because, in the initial
stages of a wash cycle, the agitation in the immediate environment of the product
is inhibited by the presence of the fabric load. Whilst this can constitute a benefit
in permitting the development of high transient concentrations of builder and surfactant,
the development of high transient peroxyacid concentrations can, as noted previously,
lead to fabric and colour damage. The compositions of the present invention, when
incorporated into concentrated detergent products delivered to the wash liquor via
a dispensing device, mitigate if not eliminate this problem.
[0030] Detergent compositions according to the present invention will normally contain from
0.5% to 20% by weight of the total detergent composition of a solid bleach activator
composition, preferably from 1.0% to 15% and more preferably from 1.0% to 10%.
[0031] Such detergent compositions will, of course, contain any of the bleaching agents
useful for detergent compositions in textile cleaning, hard surface cleaning, or other
cleaning purposes that are now known or become known. These include oxygen bleaches
as well as other bleaching agents, or mixtures thereof.
[0032] Indeed, perborate beaches, e.g., sodium perborate (e.g., mono- or tetra-hydrate)
as well as percarboxylic acid bleaching agents and salts thereof can be used herein.
Suitable examples of percarboxylic acid bleaching agents include magnesium monoperoxyphthalate
hexahydrate, the magnesium salt of meta-chloro perbenzoic acid, 4-nonylamino-4-oxoperoxybutyric
acid and diperoxydodecanedioic acid. Such bleaching agents are disclosed for instance
in the US patent, US-4 483 781 or in the European patent EP-0 133 354 and in US patent,
US-4 412 934. Highly preferred bleaching agents also include 6-nonylamino-6-oxoperoxycaproic
acid as described in US-4 634 551.
[0033] Peroxygen bleaching agents can also be used. Suitable peroxygen bleaching compounds
include sodium carbonate peroxy hydrate and equivalent "percarbonate" bleaches, sodium
pyrophosphate peroxyhydrate, urea peroxyhydrate, and sodium peroxide. Persulfate bleach
(e.g., OXONE, manufactured commercially by DuPont) can also be used. Mixtures of bleaching
agents can also be used.
[0034] Bleaching agents other than oxygen bleaching agents include for examples photoactivated
bleaching agents such as the sulfonated zinc and/or aluminum phthalocyanines. See
U.S. Patent 4,033,718, issued July 5, 1977 to Holcombe et al.
[0035] The detergent compositions herein comprise typically from 0.5% to 65% by weight of
the total composition of a bleaching agent, preferably from 1.0% to 50%.
[0036] The detergent compositions herein may typically comprise other optional ingredients
such as various detersive and aesthetic adjunct ingredients. Nonlimiting examples
of such ingredients are as follows.
Enzymes - can be included in the formulations herein for a wide variety of fabric laundering
purposes, including removal of protein-based, carbohydrate-based, or triglyceride-based
stains, for example, for the prevention of refugee dye transfer, and fabric restoration.
The enzymes to be incorporated include proteases, amylases, lipases, cellulases, and
peroxidases, as well as mixtures thereof. Other types of enzymes may also be included.
They may be of any suitable origin, such as vegetable, animal, bacterial, fungal and
yeast origin. However, their choice is governed by several factors such as pH-activity
and/or stability optima, thermostability, stability versus active detergents, builders
and so on. In this respect bacterial or fungal enzymes are preferred, such as bacterial
amylases and proteases, and fungal cellulases.
Enzymes are normally incorporated at levels sufficient to provide up to 5 mg by
weight, more typically 0.01 mg to 3 mg, of active enzyme per gram of the composition.
Stated otherwise, the compositions herein will typically comprise from 0.001% to 5%,
preferably 0.01%-1%, by weight of a commercial enzyme preparation. Protease enzymes
are usually present in such commercial preparations at levels sufficient to provide
from 0.005 to 0.1 Anson units (AU) of activity per gram of composition.
Suitable examples of proteases are the subtilisins which are obtained from particular
strains of B.subtilis and B.licheniforms. Another suitable protease is obtained from
a strain of Bacillus, having maximum activity throughout the pH range of 8-12, developed
and sold by Novo Industries A/S under the registered trade name ESPERASE. The preparation
of this enzyme and analogous enzymes is described in British Patent Specification
GB-1 243 784 of Novo. Proteolytic enzymes suitable for removing protein-based stains
that are commercially available include those sold under the tradenames ALCALASE and
SAVINASE by Novo Industries A/S (Denmark) and MAXATASE by International Bio-Synthetics,
Inc. (The Netherlands). Other proteases include Protease A (see European Patent Application
EP-130 756) and Protease B (see European Patent Application Serial No. 87303761.8,
and European Patent Application EP-130 756).
Amylases include, for example, a-amylases described in British Patent Specification
GB-1 296 839 (Novo), RAPIDASE, International Bio-Synthetics, Inc. and TERMAMYL, Novo
Industries.
The cellulases usable in the present invention include both bacterial or fungal
cellulase. Preferably, they will have a pH optimum of between 5 and 9.5. Suitable
cellulases are disclosed in U.S. Patent US-4 435 307 which discloses fungal cellulase
produced from Humicola insolens and Humicola strain DSM1800 or a cellulase 212-producing
fungus belonging to the genus Aeromonas, and cellulase extracted from the hepatopancreas
of a marine mollusk (Dolabella Auricula Solander). Suitable cellulases are also disclosed
in GB-A-2 075 028; GB-A-2 095 275 and DE-OS-2 247 832.
Suitable lipase enzymes for detergent usage include those produced by microorganisms
of the Pseudomonas group, such as Pseudomonas stutseri ATCC 19.154, as disclosed in
British Patent GB-1 372 034. See also lipases in Japanese Patent Application 53-20487,
laid open to public inspection in February 24, 1978. 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 commercial lipases include Amano-CES,
lipases ex Chromobacter viscosum, e.g. Chromobacter viscosum var. lipolyticum NRRLB
3673, commercially available from Toyo Jozo Co., Tagata, Japan; and further Chromobacter
viscosum lipases from U.S. Biochemical Corp., U.S.A. and Disoynth Co., The Netherlands,
and lipases ex Pseudomonas gladioli. The LIPOLASE enzyme derived from Humicola lanuginosa
and commercially available from Novo (see also EPO 341 947) is a preferred lipase
for use herein.
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, published October
19, 1989, by O. Kirk, assigned to Novo Industries A/S.
A wide range of enzyme materials and means for their incorporation into synthetic
detergent granules is also disclosed in U.S. Patent US-3 553 139. Enzymes are further
disclosed in U.S. Patent 4,101,457, Place et al, issued July 18, 1978, and in U.S.
Patent 4,507,219, Hughes, issued March 26, 1985, both. Enzyme materials useful for
detergent formulations, and their incorporation into such formulations, are disclosed
in U.S. Patent 4,261,868, Hora et al, issued April 14, 1981. Enzymes for use in detergents
can be stabilized by various techniques. Enzyme stabilization techniques are disclosed
and exemplified in U.S. Patent 4,261,868, issued April 14, 1981 to Horn, et al, U.S.
Patent 3,600,319, issued August 17, 1971 to Gedge, et al, and European Patent Application
Publication No. 0 199 405, Application No. 86200586.5, published October 29, 1986,
Venegas. Enzyme stabilization systems are also described, for example, in U.S. Patents
4,261,868, 3,600,319, and 3,519,570.
Enzyme Stabilizers - The enzymes employed herein are stabilized by the presence of water-soluble sources
of calcium ions in the finished compositions which provide calcium ions to the enzymes.
Additional stability can be provided by the presence of various other art-disclosed
stabilizers, especially borate species: see Severson, U.S. 4,537,706, cited above.
Typical detergents will comprise from about 1 to about 30, preferably from about 2
to about 20, more preferably from about 5 to about 15, and most preferably from about
8 to about 12, millimoles of calcium ion per liter of finished composition. This can
vary somewhat, depending on the amount of enzyme present and its response to the calcium
ions. The level of calcium ion should be selected so that there is always some minimum
level available for the enzyme, after allowing for complexation with builders, fatty
acids, etc., in the composition. Any water-soluble calcium salt can be used as the
source of calcium ion, including, but not limited to, calcium chloride, calcium sulfate,
calcium malate, calcium hydroxide, calcium formate, and calcium acetate. A small amount
of calcium ion, generally from about 0.05 to about 0.4 millimoles per liter, is often
also present in the composition due to calcium in the enzyme slurry and formula water.
Solid detergent compositions according to the present invention may include a sufficient
quantity of a water-soluble calcium ion source to provide such amounts in the laundry
liquor. In the alternative, natural water hardness may suffice.
It is to be understood that the foregoing levels of calcium ions are sufficient
to provide enzyme stability. More calcium ions can be added to the compositions to
provide an additional measure of grease removal performance. Accordingly, the compositions
herein may comprise from about 0.05% to about 2% by weight of a water-soluble source
of calcium ions. The amount can vary, of course, with the amount and type of enzyme
employed in the composition.
The compositions herein may also optionally, but preferably, contain various additional
stabilizers, especially borate-type stabilizers. Typically, such stabilizers will
be used at levels in the compositions from about 0.25% to about 10%, preferably from
about 0.5% to about 5%, more preferably from about 0.75% to about 3%, by weight of
boric acid or other borate compound capable of forming boric acid in the composition
(calculated on the basis of boric acid). Boric acid is preferred, although other compounds
such as boric oxide, borax and other alkali metal borates (e.g., sodium ortho-, meta-
and pyroborate, and sodium pentaborate) are suitable. Substituted boric acids (e.g.,
phenylboronic acid, butane boronic acid, and p-bromo phenylboronic acid) can also
be used in place of boric acid.
[0037] In addition to enzymes, the compositions herein can optionally include one or more
other detergent adjunct materials or other materials for assisting or enhancing cleaning
performance, treatment of the substrate to be cleaned, or to modify the aesthetics
of the detergent composition (e.g., perfumes, colorants, dyes, etc.). The following
are illustrative examples of such adjunct materials.
Builders - Detergent builders can optionally be included in the compositions herein to assist
in controlling mineral hardness. Inorganic as well as organic builders can be used.
Builders are typically used in fabric laundering compositions to assist in the removal
of particulate soils.
The level of builder can vary widely depending upon the end use of the composition
and its desired physical form. When present, the compositions will typically comprise
at least about 1% builder. Granular formulations typically comprise from about 10%
to about 80%, more typically from about 15% to about 50% by weight, of the detergent
builder. Lower or higher levels of builder, however, are not meant to be excluded.
Inorganic detergent builders include, but are not limited to, the alkali metal,
ammonium and alkanolammonium salts of polyphosphates (exemplified by the tripolyphosphates,
pyrophosphates, and glassy polymeric meta-phosphates), phosphonates, phytic acid,
silicates, carbonates (including bicarbonates and sesquicarbonates), sulphates, and
aluminosilicates. However, non-phosphate builders are required in some locales. Importantly,
the compositions herein function surprisingly well even in the presence of the so-called
"weak" builders (as compared with phosphates) such as citrate, or in the so-called
"underbuilt" situation that may occur with zeolite or layered silicate builders. Moreover,
the secondary (2,3) alkyl sulfate plus enzyme components perform best in the presence
of weak, nonphosphate builders which allow free calcium ions to be present.
Examples of silicate builders are the alkali metal silicates, particularly those
having a SiO2:Na2O ratio in the range 1.6:1 to 3.2:1 and layered silicates, such as
the layered sodium silicates described in U.S. Patent 4,664,839, issued May 12, 1987
to H. P. Rieck. NaSKS-6 is the trademark for a crystalline layered silicate marketed
by Hoechst (commonly abbreviated herein as "SKS-6"). Unlike zeolite builders, the
Na SKS-6 silicate builder does not contain aluminum. NaSKS-6 has the delta-Na2SiO5
morphology form of layered silicate. It can be prepared by methods such as those described
in German DE-A-3,417,649 and DE-A-3,742,043. SKS-6 is a highly preferred layered silicate
for use herein, but other such layered silicates, such as those having the general
formula NaMSixO2x+1.yH2O wherein M is sodium or hydrogen, x is a number from 1.9 to
4, preferably 2, and y is a number from 0 to 20, preferably 0 can be used herein.
Various other layered silicates from Hoechst include NaSKS-5, NaSKS-7 and NaSKS-11,
as the alpha, beta and gamma forms. As noted above, the delta-Na2SiO5 (NaSKS-6 form)
is most preferred for use herein.
[0038] Other silicates may also be useful such as for example magnesium silicate, which
can serve as a crispening agent in granular formulations, as a stabilizing agent for
oxygen bleaches, and as a component of suds control systems.
Examples of carbonate builders are the alkaline earth and alkali metal carbonates
as disclosed in German Patent Application No. 2,321,001 published on November 15,
1973.
Aluminosilicate builders are also useful in the present invention. Aluminosilicate
builders are of great importance in most currently marketed heavy duty granular detergent
compositions. Aluminosilicate builders include those having the empirical formula:
Mz(zAlO2.ySiO2)
wherein M is sodium, potassium, ammonium or substituted ammonium, z is from about
0.5 to about 2; and y is 1; this material having a magnesium ion exchange capacity
of at least about 50 milligram equivalents of CaCO3 hardness per gram of anhydrous
aluminosilicate. Preferred aluminosilicates are zeolite builders which have the formula:
Nazí(AlO2)z(SiO2)yù.xH2O
wherein z and y are integers of at least 6, the molar ratio of z to y is in the range
from 1.0 to about 0.5, and x is an integer from about 15 to about 264.
Useful aluminosilicate ion exchange materials are commercially available. These
aluminosilicates can be crystalline or amorphous in structure and can be naturally-occurring
aluminosilicates or synthetically derived. A method for producing aluminosilicate
ion exchange materials is disclosed in U.S. Patent 3,985,669, Krummel, et al, issued
October 12, 1976. Preferred synthetic crystalline aluminosilicate ion exchange materials
useful herein are available under the designations Zeolite A, Zeolite P (B), and Zeolite
X. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange
material has the formula:
Na12í(AlO2)12(SiO2)12ù.xH2O
wherein x is from about 20 to about 30, especially about 27. This material is known
as Zeolite A. Preferably, the aluminosilicate has a particle size of about 0.1-10
microns in diameter.
Organic detergent builders suitable for the purposes of the present invention include,
but are not restricted to, a wide variety of polycarboxylate compounds. As used herein,
"polycarboxylate" refers to compounds having a plurality of carboxylate groups, preferably
at least 3 carboxylates.
[0039] Polycarboxylate builder can generally be added to the composition in acid form, but
can also be added in the form of a neutralized salt. When utilized in salt form, alkali
metals, such as sodium, potassium, and lithium, or alkanolammonium salts are preferred.
Included among the polycarboxylate builders are a variety of categories of useful
materials. One important category of polycarboxylate builders encompasses the ether
polycarboxylates, including oxydisuccinate, as disclosed in Berg, U.S. Patent 3,128,287,
issued April 7, 1964, and Lamberti et al, U.S. Patent 3,635,830, issued January 18,
1972. See also "TMS/TDS" builders of U.S. Patent 4,663,071, issued to Bush et al,
on May 5, 1987. Suitable ether polycarboxylates also include cyclic compounds, particularly
alicyclic compounds, such as those described in U.S. Patents 3,923,679; 3,835,163;
4,158,635; 4,120,874 and 4,102,903.
Other useful detergency builders include the ether hydroxy polycarboxylates, copolymers
of maleic anhydride with ethylene or vinyl methyl ether, 1, 3, 5-trihydroxy benzene-2,
4, 6-trisulphonic acid, and carboxymethyloxysuccinic acid, the various alkali metal,
ammonium and substituted ammonium salts of polyacetic acids
such as ethylenediamine tetraacetic acid and nitrilotriacetic acid, as well as polycarboxylates
such as mellitic acid, succinic acid, oxydisuccinic acid, polymaleic acid, benzene
1,3,5-tricarboxylic acid, carboxymethyloxysuccinic acid, and soluble salts thereof.
Citrate builders, e.g., citric acid and soluble salts thereof (particularly sodium
salt), are polycarboxylate builders of particular importance for heavy duty detergent
formulations due to their availability from renewable resources and their biodegradability.
Citrates can also be used in combination with zeolite and/or layered silicate builders.
Oxydisuccinates are also especially useful in such compositions and combinations.
Also suitable in the detergent compositions of the present invention are the 3,3-dicarboxy-4-oxa-1,6-hexanedioates
and the related compounds disclosed in U.S. Patent 4,566,984, Bush, issued January
28, 1986. Useful succinic acid builders include the C5-C20 alkyl and alkenyl succinic
acids and salts thereof. A particularly preferred compound of this type is dodecenylsuccinic
acid. Specific examples of succinate builders include: laurylsuccinate, myristylsuccinate,
palmitylsuccinate, 2-dodecenylsuccinate (preferred), 2-pentadecenylsuccinate, and
the like. Laurylsuccinates are the preferred builders of this group, and are described
in European Patent Application 86200690.5/0,200,263, published November 5, 1986.
Other suitable polycarboxylates are disclosed in U.S. Patent 4,144,226, Crutchfield
et al, issued March 13, 1979 and in U.S. Patent 3,308,067, Diehl, issued March 7,
1967. See also Diehl U.S. Patent 3,723,322.
Fatty acids, e.g., C12-C18 monocarboxylic acids, can also be incorporated into
the compositions alone, or in combination with the aforesaid builders, especially
citrate and/or the succinate builders, to provide additional builder activity. Such
use of fatty acids will generally result in a diminution of sudsing, which should
be taken into account by the formulator.
In situations where phosphorus-based builders can be used, the various alkali metal
phosphates such as the well-known sodium tripolyphosphates, sodium pyrophosphate and
sodium orthophosphate can be used. Phosphonate builders such as ethane-1-hydroxy-1,1-
diphosphonate and other known phosphonates (see, for example, U.S. Patents 3,159,581;
3,213,030; 3,422,021; 3,400,148 and 3,422,137) can also be used.
[0040] Polymeric Soil Release Agent - Any polymeric soil release agent known to those skilled in the art can optionally
be employed in the compositions and processes of this invention. Polymeric soil release
agents are characterized by having both hydrophilic segments, to hydrophilize the
surface of hydrophobic fibers, such as polyester and nylon, and hydrophobic segments,
to deposit upon hydrophobic fibers and remain adhered thereto through completion of
washing and rinsing cycles and, thus, serve as an anchor for the hydrophilic segments.
This can enable stains occurring subsequent to treatment with the soil release agent
to be more easily cleaned in later washing procedures.
The polymeric soil release agents useful herein especially 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 about 30 oxypropylene
units wherein said mixture contains a sufficient amount of oxyethylene units such
that the hydrophile component has hydrophilicity great enough to increase the hydrophilicity
of conventional polyester synthetic fiber surfaces upon deposit of the soil release
agent on such surface, said hydrophile segments preferably comprising at least about
25% oxyethylene units and more preferably, especially for such components having about
20 to 30 oxypropylene units, at least about 50% oxyethylene units; or (b) one or more
hydrophobe components comprising (i) C3 oxyalkylene terephthalate segments, wherein,
if said hydrophobe components also comprise oxyethylene terephthalate, the ratio of
oxyethylene terephthalate:C3 oxyalkylene terephthalate units is about 2:1 or lower,
(ii) C4-C6 alkylene or oxy C4-C6 alkylene segments, or mixtures therein, (iii) poly
(vinyl ester) segments, preferably poly(vinyl acetate), having a degree of polymerization
of at least 2, or (iv) C1-C4 alkyl ether or C4 hydroxyalkyl ether substituents, or
mixtures therein, wherein said substituents are present in the form of C1-C4 alkyl
ether or C4 hydroxyalkyl ether cellulose derivatives, or mixtures therein, and such
cellulose derivatives are amphiphilic, whereby they have a sufficient level of C1-C4
alkyl ether and/or C4 hydroxyalkyl ether units to deposit upon conventional polyester
synthetic fiber surfaces and retain a sufficient level of hydroxyls, once adhered
to such conventional synthetic fiber surface, to increase fiber surface hydrophilicity,
or a combination of (a) and (b).
Typically, the polyoxyethylene segments of (a)(i) will have a degree of polymerization
of from 2 to about 200, although higher levels can be used, preferably from 3 to about
150, more preferably from 6 to about 100. Suitable oxy C4-C6 alkylene hydrophobe segments
include, but are not limited to, end-caps of polymeric soil release agents such as
MO3S(CH2)nOCH2CH2O-, 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.
Polymeric soil release agents useful in the present invention 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 C1-C4 alkyl
and C4 hydroxyalkyl cellulose; see U.S. Patent 4,000,093, issued December 28, 1976
to Nicol, et al.
Soil release agents characterized by poly(vinyl ester) hydrophobe segments include
graft copolymers of poly(vinyl ester), e.g., C1-C6 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.
Commercially available soil release agents of this kind include the SOKALAN type of
material, e.g., SOKALAN HP-22, available from BASF (West Germany).
One type of preferred 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 about 25,000 to about
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.
Another preferred polymeric soil release agent is a polyester with repeat units
of ethylene terephthalate units containing 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. Examples of this
polymer include the commercially available material ZELCON 5126 (from Dupont) and
MILEASE T (from ICI). See also U.S. Patent 4,702,857, issued October 27, 1987 to Gosselink.
Another preferred 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.
Preferred polymeric soil release agents also include the soil release agents of
U.S. Patent 4,877,896, issued October 31, 1989 to Maldonado et al, which discloses
anionic, especially sulfo aroyl, end-capped terephthalate esters.
If utilized, soil release agents will generally comprise from about 0.01% to about
10.0%, by weight, of the detergent compositions herein, typically from about 0.1%
to about 5%, preferably from about 0.2% to about 3.0%.
[0041] Chelating Agents - The detergent compositions herein may also optionally contain one or more iron
and/or manganese chelating agents. Such chelating agents can be selected from the
group consisting of amino carboxylates, amino phosphonates, polyfunctionally-substituted
aromatic chelating agents and mixtures therein, all as hereinafter defined. Without
intending to be bound by theory, it is believed that the benefit of these materials
is due in part to their exceptional ability to remove iron and manganese ions from
washing solutions by formation of soluble chelates.
Amino carboxylates useful as optional chelating agents include ethylenediaminetetraacetates,
N-hydroxyethylethylenediaminetriacetates, nitrilotriacetates,ethylenediaminetetraproprionates,
triethylenetetraaminehexaacetates, diethylenetriamine pentaacetates, and ethanoldiglycines,
alkali metal, ammonium, and substituted ammonium salts therein and mixtures therein.
Amino phosphonates are also suitable for use as chelating agents in the compositions
of the invention when at least low levels of total phosphorus are permitted in detergent
compositions, and include ethylenediaminetetrakis (methylenephosphonates), nitrilotris
(methylenephosphonates) and diethylenetriaminepentakis (methylenephosphonates) as
DEQUEST. Preferably, these amino phosphonates do not contain alkyl or alkenyl groups
with more than about 6 carbon atoms.
Polyfunctionally-substituted aromatic chelating agents are also useful in the compositions
herein. See U.S. patent 3,812,044, issued May 21, 1974, to Connor et al. Preferred
compounds of this type in acid form are dihydroxydisulfobenzenes such as 1,2-dihydroxy
-3,5-disulfobenzene.
A preferred biodegradable chelator for use herein is ethyl enediamine disuccinate
("EDDS"), as described in U.S. Patent 4,704,233, November 3, 1987, to Hartman and
Perkins.
If utilized, these chelating agents will generally comprise from about 0.1% to
about 10% by weight of the detergent compositions herein. More preferably, if utilized,
the chelating agents will comprise from about 0.1% to about 3.0% by weight of such
compositions.
[0042] Clay Soil Removal/Anti-redeposition Agents - The compositions of the present invention can also optionally contain water-soluble
ethoxylated amines having clay soil removal and anti-redeposition properties. Granular
detergent compositions which contain these compounds typically contain from about
0.01% to about 10.0% by weight of the water-soluble ethoxylated amines.
The most preferred soil release and anti-redeposition agent is ethoxylated tetraethylenepentamine.
Exemplary ethoxylated amines are further described in U.S. Patent 4,597,898, VanderMeer,
issued July 1, 1986. Another group of preferred clay soil removal/antiredeposition
agents are the cationic compounds disclosed in European Patent Application 111,965,
Oh and Gosselink, published June 27, 1984. Other clay soil removal/antiredeposition
agents which can be used include the ethoxylated amine polymers disclosed in European
Patent Application 111,984, Gosselink, published June 27, 1984; the zwitterionic polymers
disclosed in European Patent Application 112,592, Gosselink, published July 4, 1984;
and the amine oxides disclosed in U.S. Patent 4,548,744, Connor, issued October 22,
1985. Other clay soil removal and/or anti redeposition agents known in the art can
also be utilized in the compositions herein. Another type of preferred anti-redeposition
agent includes the carboxy methyl cellulose (CMC) materials. These materials are well
known in the art.
[0043] Polymeric Dispersing Agents - Polymeric dispersing agents can advantageously be utilized at levels from about
0.1% to about 7%, by weight, in the compositions herein, especially in the presence
of zeolite and/or layered silicate builders. Suitable polymeric dispersing agents
include polymeric polycarboxylates and polyethylene glycols, although others known
in the art can also be used. It is believed, though it is not intended to be limited
by theory, that polymeric dispersing agents enhance overall detergent builder performance,
when used in combination with other builders (including lower molecular weight polycarboxylates)
by crystal growth inhibition, particulate soil release peptization, and anti-redeposition.
Polymeric polycarboxylate materials can be prepared by polymerizing or copolymerizing
suitable unsaturated monomers, preferably in their acid form. Unsaturated monomeric
acids that can be polymerized to form suitable polymeric polycarboxylates include
acrylic acid, maleic acid (or maleic anhydride), fumaric acid, itaconic acid, aconitic
acid, mesaconic acid, citraconic acid and methylenemalonic acid. The presence in the
polymeric polycarboxylates herein of monomeric segments, containing no carboxylate
radicals such as vinylmethyl ether, styrene, ethylene, etc. is suitable provided that
such segments do not constitute more than about 40% by weight.
Particularly suitable polymeric polycarboxylates can be derived from acrylic acid.
Such acrylic acid-based polymers which are useful herein are the water-soluble salts
of polymerized acrylic acid. The average molecular weight of such polymers in the
acid form preferably ranges from about 2,000 to 10,000, more preferably from about
4,000 to 7,000 and most preferably from about 4,000 to 5,000. Water-soluble salts
of such acrylic acid polymers can include, for example, the alkali metal, ammonium
and substituted ammonium salts. Soluble polymers of this type are known materials.
Use of polyacrylates of this type in detergent compositions has been disclosed, for
example, in Diehl, U.S. Patent 3,308,067, issued March 7, 1967.
Acrylic/maleic-based copolymers may also be used as a preferred component of the
dispersing/anti-redeposition agent. Such materials include the water-soluble salts
of copolymers of acrylic acid and maleic acid. The average molecular weight of such
copolymers in the acid form preferably ranges from about 2,000 to 100,000, more preferably
from about 5,000 to 75,000, most preferably from about 7,000 to 65,000. The ratio
of acrylate to maleate segments in such copolymers will generally range from about
30:1 to about 1:1, more preferably from about 10:1 to 2:1. Water-soluble salts of
such acrylic acid/maleic acid copolymers can include, for example, the alkali metal,
ammonium and substituted ammonium salts. Soluble acrylate/maleate copolymers of this
type are known materials which are described in European Patent Application No. 66915,
published December 15, 1982.
Another polymeric material which can be included is polyethylene glycol (PEG).
PEG can exhibit dispersing agent perform ance as well as act as a clay soil removal/antiredeposition
agent. Typical molecular weight ranges for these purposes range from about 500 to
about 100,000, preferably from about 1,000 to about 50,000, more preferably from about
1,500 to about 10,000.
Polyaspartate and polyglutamate dispersing agents may also be used, especially
in conjunction with zeolite builders.
[0044] Brightener - Any optical brighteners or other brightening or whitening agents known in the art
can be incorporated at levels typically from about 0.05% to about 1.2%, by weight,
into the detergent compositions herein. Commercial optical brighteners which may be
useful in the present invention can be classified into subgroups which include, but
are not necessarily limited to, derivatives of stilbene, pyrazoline, coumarin, carboxylic
acid, methinecyanines, dibenzothiphene-5,5-dioxide, azoles, 5- and 6-membered-ring
heterocycles, and other miscellaneous agents. Examples of such brighteners are disclosed
in "The Production and Application of Fluorescent Brightening Agents", M. Zahradnik,
Published by John Wiley & Sons, New York (1982).
Specific examples of optical brighteners which are useful in the present compositions
are those identified in U.S. Patent 4,790,856, issued to Wixon on December 13, 1988.
These brighteners include the PHORWHITE series of brighteners from Verona. Other brighteners
disclosed in this reference include: Tinopal UNPA, Tinopal CBS and Tinopal 5BM; available
from Ciba-Geigy; Arctic White CC and Artic White CWD, available from Hilton-Davis,
located in Italy; the 2-(4-styryl-phenyl)-2H- naphthol(1,2-d)triazoles; 4,4'-bis-
(1,2,3-triazol-2-yl)-stilbenes; 4,4'-bis(styryl)bisphenyls; and the y-aminocoumarins.
Specific examples of these brighteners include 4-methyl-7-diethyl- amino coumarin;
1,2-bis(-benzimidazol-2-I)ethylene; 1,3-diphenylphrazolines; 2,5-bis(benzoxazol-2-yl)thiophene;
2-styrylnaphth-(1,2-d)oxazole; and 2-(stilbene-4-yl)-2H-naphtho- (1,2-d)triazole.
See also U.S. Patent 3,646,015, issued February 29, 1972 to Hamilton.
[0045] Suds Suppressors - Compounds for reducing or suppressing the formation of suds can be incorporated
into the compositions of the present invention. Suds suppression can be of particular
importance under conditions such as those found in European-style front loading laundry
washing machines, or in the concentrated detergency process of U.S. Patents 4,489,455
and 4,489,574, or when the detergent compositions herein optionally include a relatively
high sudsing adjunct surfactant.
A wide variety of materials may be used as suds suppressors, and suds suppressors
are well known to those skilled in the art. See, for example, Kirk Othmer Encyclopedia
of Chemical Technology, Third Edition, Volume 7, pages 430-447 (John Wiley & Sons,
Inc., 1979). One category of suds suppressor of particular interest encompasses monocarboxylic
fatty acids and soluble salts therein. See U.S. Patent 2,954,347, issued September
27, 1960 to Wayne St. John. The monocarboxylic fatty acids and salts thereof used
as suds suppressor typically have hydrocarbyl chains of 10 to about 24 carbon atoms,
preferably 12 to 18 carbon atoms. Suitable salts include the alkali metal salts such
as sodium, potassium, and lithium salts, and ammonium and alkanolammonium salts.
The detergent compositions herein may also contain non-surfactant suds suppressors.
These include, for example: high molecular weight hydrocarbons such as paraffin, fatty
acid esters (e.g., fatty acid triglycerides), fatty acid esters of monovalent alcohols,
aliphatic C18-C40 ketones (e.g. stearone), etc. Other suds inhibitors include N-alkylated
amino triazines such as tri- to hexa-alkylmelamines or di- to tetra-alkyldiamine chlortriazines
formed as products of cyanuric chloride with two or three moles of a primary or secondary
amine containing 1 to 24 carbon atoms, propylene oxide, and monostearyl phosphates
such as monostearyl alcohol phosphate ester and monostearyl di-alkali metal (e.g.
K, Na, and Li) phosphates and phosphate esters. The hydrocarbons such as paraffin
and haloparaffin can be utilized in liquid form. The liquid hydrocarbons will be liquid
at room temperature and atmospheric pressure, and will have a pour point in the range
of about -40°C and about 5°C, and a minimum boiling point not less than about 110°C
(atmospheric pressure). It is also known to utilize waxy hydrocarbons, preferrably
having a melting point below about 100°C. The hydrocarbons constitute a preferred
category of suds suppressor for detergent compositions.
[0046] Hydrocarbon suds suppressors are described, for example, in U.S. Patent 4,265,779,
issued May 5, 1981 to Gandolfo et al. The hydrocarbons, thus, include aliphatic, alicyclic,
aromatic, and heterocyclic saturated or unsaturated hydrocarbons having from about
12 to about 70 carbon atoms. The term "paraffin," as used in this suds suppressor
discussion, is intended to include mixtures of true paraffins and cyclic hydrocarbons.
Another preferred category of non-surfactant suds suppressors comprises silicone
suds suppressors. This category includes the use of polyorganosiloxane oils, such
as polydimethylsiloxane, dispersions or emulsions of polyorganosiloxane oils or resins,
and combinations of polyorganosiloxane with silica particles wherein the polyorganosiloxane
is chemisorbed of fused onto the silica. Silicone suds suppressors are well known
in the art and are, for example, disclosed in U.S. Patent 4,265,779, issued May 5,
1981 to Gandolfo et al and European Patent Application No. 89307851.9, published February
7, 1990, by Starch, M. S. Other silicone suds suppressors are disclosed in U.S. Patent
3,455,839 which relates to compositions and processes for defoaming aqueous solutions
by incorporating therein small amounts of polydimethylsiloxane fluids.
Mixtures of silicone and silanated silica are described, for instance, in German
Patent Application DOS 2,124,526. Silicone defoamers and suds controlling agents in
granular detergent compositions are disclosed in U.S. Patent 3,933,672, Bartolotta
et al, and in U.S. Patent 4,652,392, Baginski et al, issued March 24, 1987.
An exemplary silicone based suds suppressor for use herein is a suds suppressing
amount of a suds controlling agent consisting essentially of:
(i) polydimethylsiloxane fluid having a viscosity of from about 20 cs. to about 1500
cs. at 25°C;
(ii) from about 5 to about 50 parts per 100 parts by weight of (i) of siloxane resin
composed of (CH3)3 SiO1/2 units of SiO2 units in a ratio of from (CH3)3 SiO1/2 units
and to SiO2 units of from about 0.6:1 to about 1.2:1; and
(iii) from about 1 to about 20 parts per 100 parts by weight of (i) of a solid silica
gel;
In the preferred silicone suds suppressor used herein, the solvent for a continuous
phase is made up of certain polyethylene glycols or polyethylene-polypropylene glycol
copolymers or mixtures thereof (preferred), and not polypropylene glycol. The primary
silicone suds suppressor is branched/crosslinked and not linear.
To illustrate this point further, typical laundry detergent compositions with controlled
suds will optionally comprise from about 0.001 to about 1, preferably from about 0.01
to about 0.7, most preferably from abut 0.05 to about 0.5, weight % of said silicone
suds suppressor, which comprises (1) a nonaqueous emulsion of a primary antifoam agent
which is a mixture of (a) a polyorganosiloxane, (b) a resinous siloxane or a silicone
resin-producing silicone compound, (c) a finely divided filler material, and (d) a
catalyst to promote the reaction of mixture components (a), (b) and (c), to form silanolates;
(2) at least one nonionic silicone surfactant; and (3) polyethylene glycol or a copolymer
of polyethylene-polypropylene glycol having a solubility in water at room temperature
of more than about 2 weight %; and without polypropylene glycol. See also U.S. Patents
4,978,471, Starch, issued December 18, 1990, and 4,983,316, Starch, issued January
8, 1991, and U.S. Patents 4,639,489 and 4,749.740, Aizawa et al at column 1, line
46 through column 4, line 35.
The silicone suds suppressor herein preferably comprises polyethylene glycol and
a copolymer of polyethylene glycol/poly propylene glycol, all having an average molecular
weight of less than about 1,000, preferably between about 100 and 800. The polyethylene
glycol and polyethylene/polypropylene copolymers herein have a solubility in water
at room temperature of more than about 2 weight %, preferably more than about 5 weight
%.
The preferred solvent herein is polyethylene glycol having an average molecular
weight of less than about 1,000, more preferably between about 100 and 800, most preferably
between 200 and 400, and a copolymer of polyethylene glycol/polypropylene glycol,
preferably PPG 200/PEG 300. Preferred is a weight ratio of between about 1:1 and 1:10,
most preferably between 1:3 and 1:6, of polyethylene glycol:copolymer of polyethylene-polypropylene
glycol.
The preferred silicone suds suppressors used herein do not contain polypropylene
glycol, particularly of 4,000 molecular weight. They also preferably do not contain
block copolymers of ethylene oxide and propylene oxide, like PLURONIC L101.
Other suds suppressors useful herein comprise the secondary alcohols (e.g., 2-alkyl
alkanols) and mixtures of such alcohols with silicone oils, such as the silicones
disclosed in U.S. 4,798,679, 4,075,118 and EP 150,872. The secondary alcohols include
the C6-C16 alkyl alcohols having a C1-C16 chain. A preferred alcohol is 2-butyl octanol,
which is available from Condea under the trademark ISOFOL 12. Mixtures of secondary
alcohols are available under the trademark ISALCHEM 123 from Enichem. Mixed suds suppressors
typically comprise mixtures of alcohol + silicone at a weight ratio of 1:5 to 5:1.
For any detergent compositions to be used in automatic laundry washing machines,
suds should not form to the extent that they overflow the washing machine. Suds suppressors,
when utilized, are preferably present in a "suds suppressing amount." By "suds suppressing
amount" is meant that the formulator of the composition can select an amount of this
suds controlling agent that will sufficiently control the suds to result in a low-sudsing
laundry detergent for use in automatic laundry washing machines.
The compositions herein will generally comprise from 0% to about 5% of suds suppressor.
When utilized as suds suppressors, monocarboxylic fatty acids, and salts therein,
will be present typically in amounts up to about 5%, by weight, of the detergent composition.
Preferably, from about 0.5% to about 3% of fatty monocarboxylate suds suppressor is
utilized. Silicone suds suppressors are typically utilized in amounts up to about
2.0%, by weight, of the detergent composition, although higher amounts may be used.
This upper limit is practical in nature, due primarly to concern with keeping costs
minimized and effectiveness of lower amounts for effectively controlling sudsing.
Preferably from about 0.01% to about 1% of silicone suds suppressor is used, more
preferably from about 0.25% to about 0.5%. As used herein, these weight percentage
values include any silica that may be utilized in combination with polyorganosiloxane,
as well as any adjunct materials that may be utilized. Monostearyl phosphate suds
suppressors are generally utilized in amounts ranging from about 0.1% to about 2%,
by weight, of the composition. Hydrocarbon suds suppressors are typically utilized
in amounts ranging from about 0.01% to about 5.0%, although higher levels can be used.
The alcohol suds suppressors are typically used at 0.2%-3% by weight of the finished
compositions.
[0047] Fabric Softeners - Various through-the-wash fabric softeners, especially the impalpable smectite clays
of U.S. Patent 4,062,647, Storm and Nirschl, issued December 13, 1977, as well as
other softener clays known in the art, can optionally be used typically at levels
of from about 0.5% to about 10% by weight in the present compositions to provide fabric
softener benefits concurrently with fabric cleaning. Clay softeners can be used in
combination with amine and cationic softeners, as disclosed, for example, in U.S.
Patent 4,375,416, Crisp et al, March 1, 1983 and U.S. Patent 4,291,071, Harris et
al, issued September 22, 1981.
[0048] Adjunct Surfactants - The compositions herein can optionally contain various anionic, nonionic, zwitterionic,
etc. surfactants. If used, such adjunct surfactants are typically present at levels
of from about 5% to about 35% of the compositions. However, it is to be understood
that the incorporation of adjunct anionic surfactants is entirely optional herein,
inasmuch as the cleaning performance of the secondary (2,3) alkyl sulfates is excellent
and these materials can be used to entirely replace such surfactants as the alkyl
benzene sulfonates in fully-formulated detergent compositions.
[0049] Nonlimiting examples of optional surfactants useful herein include the conventional
C11-C18 alkyl benzene sulfonates and primary and random alkyl sulfates (having due
regard for the enzyme stability issues noted above), the C10-C18 alkyl alkoxy sulfates
(especially EO 1-5 ethoxy sulfates), the C10-C18 alkyl alkoxy carboxylates (especially
the EO 1-5 ethoxy carboxylates), the C10-C18 alkyl polyglycosides and their corresponding
sulfated polyglycosides, C12-C18 alpha-sulfonated fatty acid esters, C12-C18 alkyl
and alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), C12-C18
betaines and sulfobetaines ("sultaines"), C10-C18 amine oxides, and the like. Other
conventional useful surfactants are listed in standard texts.
[0050] One particular class of adjunct nonionic surfactants especially useful herein comprises
the polyhydroxy fatty acid amides of the formula:

wherein: R1 is H, C1-C8 hydrocarbyl, 2-hydroxyethyl, 2-hydroxy propyl, or a mixture
thereof, preferably C1-C4 alkyl, more preferably C1 or C2 alkyl, most preferably C1
alkyl (i.e., methyl); and R2 is a C5-C32 hydrocarbyl moiety, preferably straight chain
C7-C19 alkyl or alkenyl, more preferably straight chain C9-C17 alkyl or alkenyl, most
preferably straight chain C11-C19 alkyl or alkenyl, or mixture thereof; and Z is a
polyhydroxyhydrocarbyl moiety having a linear hydrocarbyl chain with at least 2 (in
the case of glyceraldehyde) or at least 3 hydroxyls (in the case of other reducing
sugars) directly connected to the chain, or an alkoxylated derivative (preferably
ethoxylated or propoxylated) thereof. Z preferably will be derived from a reducing
sugar in a reductive amination reaction; more preferably Z is a glycityl moiety. Suitable
reducing sugars include glucose, fructose, maltose, lactose, galactose, mannose, and
xylose, as well as glyceraldehyde. As raw materials, high dextrose corn syrup, high
fructose corn syrup, and high maltose corn syrup can be utilized as well as the individual
sugars listed above. These corn syrups may yield a mix of sugar components for Z.
It should be understood that it is by no means intended to exclude other suitable
raw materials. Z preferably will be selected from the group consisting of -CH2-(CHOH)n-CH2OH,
-CH(CH2OH)-(CHOH)n-1- CH2OH, -CH2-(CHOH)2(CHOR')(CHOH)-CH2OH, where n is an integer
from 1 to 5, inclusive, and R' is H or a cyclic mono- or poly-saccharide, and alkoxylated
derivatives thereof. Most preferred are glycityls wherein n is 4, particularly -CH2-(CHOH)4-CH2OH.
In Formula (I), R1 can be, for example, N-methyl, N-ethyl, N-propyl, N-isopropyl,
N-butyl, N-isobutyl, N-2-hydroxy ethyl, or N-2-hydroxy propyl. For highest sudsing,
R1 is preferably methyl or hydroxyalkyl. If low sudsing is desired, R1 is preferably
C2-C8 alkyl, especially n-propyl, iso-propyl, n-butyl, iso-butyl, pentyl, hexyl and
2-ethyl hexyl.
R2-CO-N< can be, for example, cocamide, stearamide, oleamide, lauramide, myristamide,
capricamide, palmitamide, tallowamide, etc.
While polyhydroxy fatty acid amides can be made by the process of Schwartz, U.S.
2,703,798, contamination with cyclized by-products and other colored materials can
be problematic. As an overall proposition, the preparative methods described in WO-9,206,154
and WO-9,206,984 will afford high quality polyhydroxy fatty acid amides. The methods
comprise reacting N-alkylamino polyols with, preferably, fatty acid methyl esters
in a solvent using an alkoxide catalyst at temperatures of about 85°C to provide high
yields (90-98%) of polyhydroxy fatty acid amides having desirable low levels (typically,
less than about 1.0%) of sub-optimally degradable cyclized by-products and also with
improved color and improved color stability, e.g., Gardner Colors below about 4, preferably
between 0 and 2. (With compounds such as butyl, iso-butyl and n-hexyl, the methanol
introduced via the catalyst or generated during the reaction provides sufficient fluidization
that the use of additional reaction solvent may be optional.) If desired, any unreacted
N-alkylamino polyol remaining in the product can be acylated with an acid anhydride,
e.g., acetic anhydride, maleic anhydride, or the like, to minimize the overall level
of such residual amines in the product. Residual sources of classical fatty acids,
which can suppress suds, can be depleted by reaction with, for example, triethanolamine.
By "cyclized by-products" herein is meant the undesirable reaction by-products
of the primary reaction wherein it appears that the multiple hydroxyl groups in the
polyhydroxy fatty acid amides can form ring structures which are, in the main, not
readily biodegradable. It will be appreciated by those skilled in the chemical arts
that the preparation of the polyhydroxy fatty acid amides herein using the di- and
higher saccharides such as maltose will result in the formation of polyhydroxy fatty
acid amides wherein linear substituent Z (which contains multiple hydroxy substituents)
is naturally "capped" by a polyhydroxy ring structure. Such materials are not cyclized
by-products, as defined herein.
The foregoing polyhydroxy fatty acid amides can also be sulfated, e.g., by reaction
with SO3/pyridine, and the resulting sulfated material used as an adjunct anionic
surfactant herein.
Such adjunct surfactants can be added separately to the compositions herein or,
as noted above, can be combined with the secondary (2,3) alkyl sulfates to provide
dense, high-active, mixed detergent particles.
[0051] Other Ingredients - A wide variety of other ingredients useful in detergent compositions can be included
in the compositions herein, including other active ingredients, carriers, hydrotropes,
processing aids, dyes or pigments. If high sudsing is desired, suds boosters such
as the C10-C16 alkanolamides can be incorporated into the compositions, typically
at 1%-10% levels. The C10-C14 monoethanol and diethanol amides illustrate a typical
class of such suds boosters. Use of such suds boosters with high sudsing adjunct surfactants
such as the amine oxides, betaines and sultaines noted above is also advantageous.
If desired, soluble magnesium salts such as MgCl2, MgSO4, and the like, can be added
at levels of, typically, 0.1%-2%, to provide additional sudsing.
Various detersive ingredients employed in the present compositions optionally can
be further stabilized by absorbing said ingredients onto a porous hydrophobic substrate,
then coating said substrate with a hydrophobic coating. Preferably, the detersive
ingredient is admixed with a surfactant before being absorbed into the porous substrate.
In use, the detersive ingredient is released from the substrate into the aqueous washing
liquor, where it performs its intended detersive function.
To illustrate this technique in more detail, a porous hydrophobic silica (trademark
SIPERNAT D10, DeGussa) is admixed with a proteolytic enzyme solution containing 3%-5%
of C13-15 ethoxylated alcohol EO(7) nonionic surfactant. Typically, the enzyme/surfactant
solution is 2.5 X the weight of silica. The resulting powder is dispersed with stirring
in silicone oil (various silicone oil viscosities in the range of 500-12,500 can be
used). The resulting silicone oil dispersion is emulsified or otherwise added to the
final detergent matrix. By this means, ingredients such as the aforementioned enzymes,
bleaches, bleach activators, bleach catalysts, photoactivators, dyes, fluorescers,
fabric conditioners and hydrolyzable surfactants can be "protected" for use in detergents.
[0052] The detergent compositions herein will preferably be formulated such that, during
use in aqueous cleaning operations, the wash water will have a pH of between about
6.5 and about 11, preferably between about 7.5 and about 10.5. Techniques for controlling
pH at recommended usage levels include the use of buffers, alkalis, acids, etc., and
are well known to those skilled in the art.
Experimental data
[0053] The following are typical, nonlimiting examples which illustrate the detergent compositions
and uses of the secondary (2,3) alkyl sulfates (SAS) according to this invention.
[0054] Tetra Acetyl Ethylene Diamine (TAED) in fine powder form (purity ca 99.0%, particle
size 90% by weight less than 150 micrometers) was agglomerated with a secondary (2,3)
alkyl sulfate (C16; 2,3 isomer, 91.8% active). The agglomeration was carried out in
a small mixer and the resultant, wet, agglomerate was then dried by placing overnight
in a vacuum oven at 40°C. Said resultant agglomerate was then sieved using a screen
mesh size 1180 um through 425 um.
The TAED/SAS agglomerate obtained contained 85 % of TAED and 15% of SAS.
[0055] A reference TAED agglomerate was prepared by agglomerating the same TAED powder with
molten TAE25 as an agglomerating agent in the same mixing device as above. However,
so drying of said agglomerate is not needed as TAE25 simply solidifies. Said agglomerate
was made using a TAED: TAE25 ratio of 85 %: 15 %. Particles were then cooled and sized
to the same standards as above.
[0056] The rate of perhydrolysis of both these agglomerates were measured.
Beaker perhydrolysis was measured in pots containing 1 liter of distiled water. A
percarbonate (PC)/carbonate(C) system was used. In each pot we put 1.75 g percarbonate,
0.89 g of carbonate and 0.6 g of either TAED/SAS agglomerate or TAED/TAE25 agglomerate,
10 ml aliquots were taken after 3 minutes and 5 minutes. Said aliquots were added
to 20 ml glacial acetic acid and 5 ml potassium iodide (1%) indicator solution and
this was then titrated against 0.01M thiosulphate.
Results
[0057]
Rate of perhydrolysis in % |
TAED/SAS agglomerate |
TAED/TAE25 agglomerate |
After 3 mins |
75 |
60 |
After 5 mins |
85 |
70 |
[0058] According to the present invention, the results show that when the bleach activator,
i.e. TAED is agglomerated with a secondary (2,3) alkyl sulfate the rate of perhydrolysis
is significantly increased compared to particulate wherein the TAED is agglomerated
with TAE25. Additionally a satisfactorily perhydrolysis rate is obtained without requiring
a decrease in the particle size.
[0059] Furthermore, the SAS has been found to be stable during the agglomeration process
and during the storage of the resulting agglomerate.
[0060] The particulate bleach activator material as for example the TAED/SAS agglomerate
can be incorporated in different detergent compositions such as the following detergent
matrix (composition in parts by weight):
C12 Linear Alkyl Benzene Sultanate |
9.0 |
Tallow Alkyl Sulphate |
2.8 |
Dobanol 45E7 |
3.8 |
Zeolite A |
20 |
Citrate |
6.5 |
Carbonate |
15.0 |
Silicate (SiO2:Na2O=2:1) |
3.5 |
Perborate monohydrate |
16.0 |
Sokalan(R) CP45 |
4.0 |
Miscellaneous |
up to 100 |
[0061] The amount of agglomerate in the composition was such as to provide an active level
of 5% by weight of TAED versus the total composition.