TECHNICAL FIELD
[0001] The present invention relates to a composition suitable for use in manual dishwashing
comprising high levels of surfactant and suspended beads. The composition has sufficient
viscosity to keep the beads stably suspended over time, but yet is pourable and dissolves
quickly in water during the dishwashing process.
BACKGROUND OF THE INVENTION
[0002] It has long been desirable to be able to prepare liquid compositions comprising incompatible
ingredients. The problem to be over come however is finding a method by which the
incompatible ingredients can be kept separate and thus stable before use. One solution
to this problem is to formulate the composition such that the incompatible ingredients
are in different phases of the composition. For example by preparing one incompatible
ingredient in solid form, like a bead, prill or capsule. From a consumer acceptance
standpoint, it is essential that such beads are stably suspended through out the composition.
[0003] Methods of suspending particulates in a liquid composition are known in the art.
One way of suspending particles is to "structure" the liquid. Structured liquids may
be broadly characterised in that they comprise high levels of electrolyte (e.g. surfactant)
and in that the liquids form 'micelles' or 'lamellar layers' discussed in greater
detail in
US 5 147 576 to Montague et al. Liquids prepared in this way are however difficult to pour and owing to the existence
of the lamellar layers, are often opaque.
[0004] Another method of suspending particles in a liquid composition is the use of thickening
agents such as polymers or gums. Thickening gums such as xanthan gum or rhamsan gum
provide good viscosity but are liable to thicken the composition to such an extent
that the composition becomes difficult to pour (greater than 2500 cps). Further more
such gums are susceptible to the presence of electrolytes, such as surfactants, in
the composition and thus the level of surfactant in such compositions must be low
(less than about 10% by weight do the composition). However low level of electrolyte,
especially surfactant in a cleaning composition negatively impacts the performance
of the composition to the point where the composition no longer adequately performs
as a detergent. Thickening polymers such as acrylate-containing polymers are compatible
with surfactants, but provide inadequate viscosity to stably suspend the particulate
resulting in the, at least partial, settling of the beads over time.
[0005] All of the above methods of suspending beads in liquid compositions rely on increasing
the viscosity of the composition. However increasing viscosity has a negative impact
on dissolution of the composition in water. While not wanted to be limited by theory,
it is believed that the surfactant and/or suspending agents form large structures,
micelles or lamellar layers. The formation of such structures reduces or retards the
penetration of water and hydration of the system that would then break the structures
down. The larger and more hydrophobic the structures the more difficult they are to
hydrate and thus dissolve. It has therefore been the object of the present invention
to provide a composition that is capable of stably suspended beads, comprises sufficient
surfactant to provide adequate cleaning and yet dissolves rapidly in water at temperatures
suitable for hand washing.
SUMMARY OF THE INVENTION
[0006] According to the present invention there is provided a composition, suitable for
use as a manual dishwashing composition, comprising stably suspended beadsat least
20% surfactant, and capable of rapid dissolution measured as described herein.
DETAILED DESCRIPTION OF THE INVENTION
[0007] The composition of the present invention comprises beads. The beads are suspended
in a liquid composition which is thickened in order to be able to suspend the beads.
The benefit of the present composition is that it is able to stably suspend the beads,
but can still dissolve readily on contact with water. By stable it is meant that at
least 80% of the beads are still evenly suspended in the composition after a period
of storage of 30 days at 21°C. The composition of the present invention preferably
has a viscosity of 100-2000 cps, more preferably a viscosity of 400-1000 cps. The
viscosity measurement is taken when the product is neat i.e. undiluted. This is defined
as being the 100% composition concentration.
[0008] In a preferred embodiment, the composition of the present invention, at 80% composition
concentration, has a viscosity of less than the composition at 100% composition concentration.
The viscosity measurement is taken after the composition has been diluted by the addition
of deionised water. The composition is diluted with deionised water at a ratio of
concentrated composition to water of 4:1. This is defined as being the 80% concentrated
composition. Measuring the viscosity of the composition when neat and when diluted
to a small extent allows the manufacturer to prepare a dilution profile for the composition.
A composition, which exhibits a reduction in viscosity after dilution to 80% concentration,
will dissolve well in water as opposed to a composition that exhibits an increase
in viscosity after equal dilution. Typically compositions of the prior art exhibiting
an increase in viscosity at 80% concentrated composition. On further dilution (60%,
40%, 20% concentrated composition) all compositions, including those of the prior
art and the present invention, show a decrease in viscosity.
[0009] To measure the viscosity of the 100% composition concentration place 100g of the
neat composition in a clean, dry beaker and measure viscosity of the composition using
a Brookfield cylinder viscometer, model #VDVII+ with a S-18 spindle at 21°C at a shear
rate of 30rpm. To measure the viscosity of the 80% composition concentration place
80g of the composition in a clean, dry beaker and add 20g of deionised water to dilute
the product by a ratio of 4:1. The product is stirred until all composition is visually
dissolved. The viscosity of the composition is then measured as above.
[0010] As discussed above the rate of dissolution of the composition is affected by the
viscosity and the level of surfactant in the composition. It was therefore an object
of the present invention to provide compositions that are able to clean well, stably
suspend beads, but also dissolve well. The following test procedure is used to measure
the dissolution of a composition in water.
[0011] The test requires the use of a Suds Cylinder Machine. The machine comprises eight
cylinders, each of which may be independently rotated at a rate of 20-22 rpm. Each
cylinder measures 12 inches high x 4 inches diameter and are marked vertically with
inch adhesive measuring tape with gradations showing 1/8 inch markings. The zero of
the tape indicates the level of 500 milliliters of solution. Only one side of the
machine is used for this test.
[0012] The machine rotates 8 cylinders around a fixed central axis at a rate of 22 rpm.
It is advisable to use no more than 4 cylinders per test as it is difficult to accurately
monitor more cylinders during the test.
[0013] Measure out 500mL of water at 21°C +/- 2°C into the cylinders required for the test.
To each cylinder, slowly pipette 0.6cc of dyed* test composition into the center of
the cylinder. Allow the product to sink to the bottom of the cylinder. Carefully,
place the cylinders into the Suds Cylinder Machine ensuring that the cylinders are
not shaken and the water/composition is not disrupted. Rotate the cylinders, stop
and observe dissolution after each full rotation. A full rotation is understood as
meaning that the cylinder are rotated through 360°, being returned to the original
stating position at the end of the rotation. Dissolution is said to be achieved when
the dyed composition is no longer visible in the water. Record the number of full
rotations required to dissolve the composition. According to the present test, compositions
that dissolve satisfactorily dissolve in less than 10 rotations of the cylinders.
Compositions that dissolve well, dissolve in less than 8 rotations and preferred composition
dissolve in less than 6 rotations.
[0014] The composition of the present invention has preferably 50% or greater transmittance
of light, more preferably 75% or greater, even more preferably 80% or greater transmittance
of light using a 1 cm cuvette, at at least one wavelength in the range from 410-800
nanometers (visible light) in the absence of dyes, beads or opacifying agents. Light
transmittance is an unitless number defined as the ratio of transmitted light after
passing through a sample and the incident light entering a sample. Transmittance was
measured using a NovaSpec Spec 20 Spectrophotometer. The compositions described were
added to a 1 cm cuvette and inserted into the instrument. % Transmittance was read
directly.
[0015] The relationship between viscosity, surfactant concentration in the composition,
ability to suspend beads and dissolution is supported by the following data comparing
compositions of the present invention A, B, C and D (microemulsion); compositions
employing unsuitable suspending agents, R and S; and compositions of the prior art,
X and Y. The composition formulae are presented in Table 1. The viscosity, bead suspension,
pourability and dissolution data of these formulae is presented in Table 2. All compositions
comprise 0.1% liposphere (tradename) beads available from Lipotechnologies.
Table 1
|
A |
B |
C |
D |
R |
S |
X |
Y |
|
|
|
|
|
|
|
|
|
Sodium Alkyl Ethoxy Sulfate |
26.5 |
26.5 |
26.5 |
26.5 |
26.5 |
26.5 |
29.1 |
28.8 |
Alkyl Dimethyl Amine Oxide |
6 |
6 |
6 |
5 |
6 |
6 |
-- |
6 |
Alkyl Polysaccharide |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
2 |
Alkyl Amido Propyl Betaine |
-- |
-- |
-- |
-- |
-- |
-- |
4.8 |
-- |
Alcohol Ethoxylated Nonionic |
2 |
2 |
2 |
2 |
2 |
2 |
2.1 |
4 |
Gellan Gum |
0.02 |
0.02 |
0.01 |
0.02 |
-- |
-- |
-- |
0.02 |
Polyacrylate |
-- |
-- |
-- |
-- |
2.0 |
-- |
1 |
-- |
Laponite |
-- |
-- |
-- |
-- |
-- |
2.0 |
-- |
-- |
Ethanol |
4.5 |
6.0 |
4.5 |
-- |
-- |
2.0 |
1.5 |
5.2 |
Polypropylene Glycol 2000 MW |
1 |
1 |
1 |
7 |
4.5 |
5 |
-- |
-- |
Sodium Chloride |
1 |
1 |
1 |
6 |
-- |
-- |
-- |
-- |
Calcium Xylene Sulfonate |
-- |
-- |
-- |
1 |
1 |
1 |
-- |
4.1 |
Sodium Cumene Sulfonate |
1.6 |
1.6 |
1.6 |
1 |
1 |
1 |
1.0 |
-- |
1.3-Bis (aminomethyl) cyclohexane |
0.5 |
0.5 |
0.5 |
0.5 |
-- |
-- |
-- |
-- |
Beads |
0.1% |
0.1% |
0.1% |
0.1% |
0.1% |
0.1% |
0.1% |
0.1% |
Table 2
Composition |
|
Viscosity (cps) 100% conc. |
Beads stably suspended |
Composition Pourable |
Dissolution (rotations) |
A |
|
650 |
Yes |
Yes |
7.5 |
B |
|
450 |
Yes |
Yes |
5.5 |
C |
|
400 |
Yes |
Yes |
5.5 |
D |
|
400 |
Yes |
Yes |
3.5 |
R |
|
850 |
Yes (hazy) |
Yes |
>15 |
S |
|
680 |
No |
Yes |
11 |
X |
|
2565 |
Yes |
No |
> 15 |
Y |
|
650 |
Yes |
Yes |
> 15 |
[0016] Compositions A, B, C and D, representing the present invention, show the acceptable
dissolution, stably suspends beads, and are pourable. The compositions of the prior
art and those using unsuitable suspending agents all exhibit problems. Composition
R, is successful in stably suspending the beads, is pourable but does not dissolve
sufficiently well. Composition S, does not stably suspend beads and dissolves poorly.
Composition X is so thick it is unpourable and dissolves badly. Composition Y also
dissolves badly.
Beads
[0017] The compositions of the present invention comprise beads. Suitable beads for use
in such compositions are available in the prior art. The beads may be selected from
microcapsules or preferably porous, sponge-like beads. Microcapsule beads comprise
a shell surrounding a core. Said core may comprise a void or a separate mass. Porous
beads are preferably homogenous and present a sponge-like structure. Either type of
bead may serve as a carrier for an ingredient of the composition.
[0018] The beads may be of any shape but are preferably three-dimensional. More preferably
the beads are substantially rounded, more preferably substantially spherical. The
beads of the present invention preferably have an average diameter of from about 100
to about 3,000 microns, preferably from about 500 to about 2000 microns, most preferably
from about 750 to about 1250 microns.
[0019] The beads of the present invention are preferably dissolvable, crushable, squeezable
or ruptureable, such that any active ingredients carried within the beads may be released.
Most preferably the beads dissolve on contact with the wash water used in the cleaning
process. It is envisaged that the composition comprising the beads can be added to
the wash water or added to a cleaning implement for example a sponge or clothwhich
has or will be moistened with wash water. In this latter situation the beads may dissolve
on contact with the water held within the wash implement or may be crushed, squeezed
or otherwise ruptured by the mechanical force of the users hand during use of the
wash implement.
[0020] The present compositions may comprise beads at a wide variation of levels. The beads
are typically included in the present compositions at a level of from about 0.001%
to about 99.9%, preferably from about 0.005% to about 50%, and more preferably from
about 0.01% to about 20%, by weight of the composition.
[0021] The beads can be made from a wide variety of materials. Such materials are typically
polymeric and are designed to resist becoming solubilized in the chemical matrix of
the present compositions. Non-limiting examples of materials suitable for making the
beads herein include urea-formaldehydes, melamineformaldehydes, phenolformaldehydes,
gelatin, poly(vinyl alcohol), poly(vinyl pyrrolidone), polyacrylates, polyamides,
polyurethane, polymethacrylates, polyepoxides, cellulose acetate, cellulose nitrate,
cellulose acetate butyrate, ethyl cellulose polyester, polychlorotrifluoroethylene
(e.g. KEL-F), ethyl/vinyl acetate, saran, polystyrene, zein, paraffin wax, animal
wax, vegetable wax, microcrystalline wax, polyethylene wax, agar, polyoxymethylene
urea, methophenols and the like. Preferred bead materials include gelatin, agar, polyoxymethylene
urea, methophenols and mixtures thereof. Other suitable bead materials are disclosed
in, e.g.,
U.S. Patent Nos. 2,800,458;
3,159,585;
3,516,846;
3,533,958;
3,697,437;
3,888,689;
3,996,156;
3,965,033;
4,010,038;
4,016,098;
4,087,376;
5,591,146;
UK Patent Nos. 2,006,709 and
2,062,570. Preferred microcapsule beads are available from Lipotechnologies under the tradename
lipocapsules. Preferred porous beads are available from Lipotechnolgies under the
tradename Lipospheres.
[0022] The porous, sponge-like beads are preferred over the microcapsule beads as they have
been found to be more easily suspended in the compositions of the present invention.
This is believed to be due to the fact that the composition can more easily penetrate
the bead. The penetration of the composition into the bead has the effect of bringing
the density of the bead and the composition to more similar levels. The bead and composition
can be said to be density matched.
[0023] A variety of processes known in the art can be used to make the beads herein. Examples
of processes for making microcapsule beads are described in
U.S. Patent Nos. 2,800,458;
3,159,585;
3,516,846;
3,516,941;
3,533,958;
3,697,437;
3,778,383;
3,888,689;
3,965,033;
3,996,156;
4,010,038;
4,016,098;
4,087,376;
4,089,802;
4,100,103;
4,251,386;
4,269,729;
4,303,548;
4,460,722; and
4,610,927;
UK Patent Nos. 1,156,725;
1,483,542;
2,041,319 and
2,048,206; and
Benita, Simon (ed.), MICROENCAPSULATION: METHODS AND INDUSTRIAL APPLICATIONS (Marcel
Dekker, Inc. 1996). Preferably the microcapsules are prepared by a precipitation method whereby polymers
in solution are precipitated around a hydrophobic core material, resulting in a clear,
non-pigmented shell surrounding a single droplet or particle of core material. By
contrast porous, sponge-like beads are prepared by an extrusion process and consist
of many small droplets or particles trapped within a polymer matrix more like a sponge
than a capsule. Said beads are available from Lipotechnologies.
[0024] Suitable ingredients that may be incorporated into the beads include any ingredient
which is incompatible with the ingredients of another phase of the composition. Preferred
ingredients for incorporation into the beads include perfume, enzyme, skin conditioning
agent and bleach.
[0025] Any perfume suitable for perfuming the present composition or enzyme, described in
more detail later, may be applied to or into the beads. By skin conditioning agent
it is meant a component that improves the barrier health of the skin or provides a
superficial skin benefit sensation. Agents providing an improvement in skin barrier
health include moisturizers, e.g. oils, glycerin, which replenishes skin lipids, and
bioactives that effectively feed the skin nutrients that promote skin health. Examples
of bioactives include vitamins, particularly vitamin E and A and vitamin precursors,
such as niacinamide.
[0026] Agents that provide a superficial benefit sensation to the skin include agents which
cool or sooth the skin, but do not clearly aid skin barrier health. Examples include
menthols and peppermint, Frescolat®, thymol.
[0027] Examples of preferred skin conditioning agents include algae, vitamins, Aloe vera
and oils, such as sunflower, Aloe vera, grapeseed, jojoba.
[0028] Another preferred ingredient for incorporation into the beads is a bleach. Suitable
bleaches include hydrophobic bleaches, preferably alkyl peracids and peroxides. The
most preferred choice of bleach is a benzoyl peroxide.
Surfactant
[0029] The composition of the present invention comprises at least 20%, more preferably
at least 25% surfactant. Surfactants may be selected from the group consisting of
amphoteric, zwitterionic, nonionic, anionic, cationic surfactants and mixtures thereof.
A selection of preferred surfactants are described below, however it is envisaged
that any known and suitable surfactant for the purpose may be employed in the compositions
of the present invention.
[0030] Amphoteric surfactants are preferred surfactants. Specifically preferred amphoteric
surfactants useful in the present invention are selected from amine oxide surfactants.
Amine oxides are semi-polar nonionic surfactants and include water-soluble amine oxides
containing one linear or branched alkyl moiety of from 10 to 18 carbon atoms and 2
moieties selected from the group consisting of alkyl groups and hydroxyalkyl groups
containing from 1 to 3 carbon atoms; water-soluble phosphine oxides containing one
alkyl moiety of from 10 to 18 carbon atoms and 2 moieties selected from the group
consisting of alkyl groups and hydroxyalkyl groups containing from 1 to 3 carbon atoms;
and water-soluble sulfoxides containing one alkyl moiety of from 10 to 18 carbon atoms
and a moiety selected from the group consisting of alkyl and hydroxyalkyl moieties
of from 1 to 3 carbon atoms.
[0031] Suitable nonionic detergent surfactants are generally disclosed in
U.S. Patent 3,929,678, Laughlin et al., issued December 30, 1975, at column 13, line 14 through column 16, line 6, incorporated herein by reference.
Preferred nonionic surfactants include the condensation products of aliphatic alcohols
with from 1 to 25 moles of ethylene oxide. The alkyl chain of the aliphatic alcohol
can either be straight or branched, primary or secondary, and generally contains from
8 to 22 carbon atoms. Particularly preferred are the condensation products of alcohols
having an alkyl group containing from 10 to 20 carbon atoms with from 2 to 18 moles
of ethylene oxide per mole of alcohol. This category of nonionic surfactant is referred
to generally as "alkyl ethoxylates."
[0032] Other suitable surfactants include alkylpolyglycosides, fatty acid or polyhydroxy
fatty amide surfactants known in the art.
[0033] Other particularly preferred surfactants are anionic surfactants. Suitable anionic
surfactants for use in the compositions herein include water-soluble salts or acids
of the formula ROSO
3M wherein R preferably is a C
6-C
20 linear or branched hydrocarbyl, preferably an alkyl or hydroxyalkyl having a C
10-C
20 alkyl component, more preferably a C
10-C
14 alkyl or hydroxyalkyl, and M is H or a cation, e.g., an alkali metal cation or ammonium
or substituted ammonium, but preferably sodium. Alkyl sulfates, alkyl ethoxylated
sulfates and alkyl propoxylated sulfates are contemplated herein.
[0034] Other suitable anionic surfactants for use herein are alkyl sulphonates including
water-soluble salts or acids of the formula RSO
3M wherein R is a C
6-C
20 linear or branched, saturated or unsaturated alkyl group, preferably a C
10-C
20 alkyl group and more preferably a C
10-C
14 alkyl group, and M is H or a cation, e.g., an alkali metal cation.
[0035] The particular surfactants used can therefore vary widely depending upon the particular
end-use envisioned. Suitable additional surfactants are described in detail in the
copending provisional patent application of Chandrika Kasturi et al., entitled "Liquid
Detergent Compositions Comprising Polymeric Suds Enhancers", having P & G Case No.
6938P, application serial no. 60/066,344, incorporated above. Preferably the composition
comprises a surfactant selected from anionic, amphoteric, nonionic surfactants and
mixtures thereof.
[0036] In a preferred embodiment, the present composition comprises at least 25% surfactant.
In a further preferred embodiment the composition. In a further preferred embodiment
the surfactant is a surfactant system consisting of at least 20% anionic surfactant,
at least 4% amine oxide and at least 1% alkyl ethoxylated non-ionic surfactant.
Structuring Agent
[0037] The present compositions preferably comprise a structuring agent. A structuring agent
can be important to suspend the microcapsules in the composition to prevent the beads
from settling out of solution. Thus a structuring agent can be important in achieving
stable suspension of the beads.
[0038] The level and type of structuring agent is preferably selected to provide viscoelastic
properties. The preferred structuring agents provide a weak gel formation matrix,
in which polymeric or non-polymeric ingredients interact with each other and form
hydrogen and/or hydrophobic bonding. Some functional groups on the molecules have
electrostatic repulsive forces that can prevent coagulation of the particles in the
composition. The weakly formed gel matrix resulting from the preferred structuring
agents herein is capable of suspending the beads. When present, structuring agents
may be present at a level of from about 0.001% to about 10%, more preferably from
about 0.005% to about 5%, even more preferably from about 0.01% to about 1% and most
preferably from 0.01-0.01 % by weight of the composition.
[0039] The structuring agents herein can be selected from materials or mixtures of polymeric
gums, microbial polysaccharides and polysaccharide derivatives such as pectine, alginate,
arabinogalactan, carageenan, gellan gum, xanthum gum, guar gum. Preferred structuring
agents herein include those selected from the group consisting of gellan gum, guar
gum, xanthan gum, and mixtures thereof.
[0040] Gellan gum is a heteropolysaccharide prepared by fermentation of Pseudomonaselodea
ATCC 31461. Gellan gum is available from CP Kelco U.S., Inc. under various names,
including KELCOGEL
®, KELCOGEL
® LT100, KELCOGEL
® AFT, KELCOGEL
® AF, KELCOGEL
® PC, and KELCOGEL
® F. Processes for preparing gellan gum are described in
U.S. Patent No. 4,326,052 (Kang et al), issued Apr. 20, 1982;
U.S. Patent No. 4,326,053 (Kang et al), issued Apr. 20, 1982;
U.S. Patent No. 4,377,636 (Kang et al), issued Mar. 22, 1983; and
U.S. Patent No. 4,385,123 (Kang et al), issued May 24, 1983.
Optional Ingredients
[0041] The compositions of the present invention may also comprise optional ingredients
for example diamine, additional surfactants, solvents, polymeric suds stabiliser,
enzymes, builder, perfume, chelating agent and mixtures thereof.
[0042] All parts, percentages and ratios used herein are expressed as percent weight unless
otherwise specified. All documents cited are, in relevant part, incorporated herein
by reference.
Solvent
[0043] The present compositions may preferably comprise a solvent. Suitable solvents include
diols polymeric glycols and mixtures of both diols and polymeric glycols. Diols suitable
for use in the present invention have the following formula:

wherein n = 0- 3, R
7 = H, methyl or ethyl; and R
8 = H, methyl, ethyl, propyl, isopropyl, butyl and isoubutyl. Preferred diols include
propylene glycol, 1,2 hexanediol, 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.
When diols are present, the present compositions will comprise at least 0.5 %, more
preferably at least 1%, even more preferably still, at least 3% by weight of the composition
of diols. The composition will also preferably contain no more than 20%, more preferably
no more than 10%, even more preferably, no more than 6% by weight of the composition
of diols.
[0044] Polymeric glycols, which comprise ethylene oxide (EO) and propylene oxide (PO) groups
may also be included in the present invention. These materials are formed by adding
blocks of ethylene oxide moieties to the ends of polypropylene glycol chains. Polymeric
gycols suitable for use in the present invention are of the following formula: (PO)
x(EO)
yH wherein x+y is from 17 to 68, and x/(x+y) is from 0.25 to 1.0. A preferred polymeric
glycol is a polyproylene glycol (corresponding to when y ≈ 0) having an average molecular
weight of between 1000 to 5000, more preferably between 2000 to 4000, most preferably
2000 to 3000.
[0045] When polymeric glycols are present the present liquid detergent compositions will
contain at least 0.25 %, more preferably at least 0.5 %, even more preferably still,
at least 0.75 % by weight of the composition of polymeric glycols. The composition
will also preferably contain no more than 5 %, more preferably no more than 3 %, even
more preferably, no more than 2 % by weight of the composition.
[0046] To insure satisfactory physical stability, whenever polymeric glycols are added to
a liquid dishwashing composition, it may be necessary to also include either a diol
and/or an alkali metal inorganic salt, such as sodium chloride. Suitable amounts of
diols to provide physical stability are in the amounts in the ranges found above,
while a suitable amount of an alkali metal inorganic salt is at least 0.1 % and less
than 1.5%, preferably less than 0.8 % by weight of the composition.
[0047] As discussed above, the addition of diols can improve the physical and enzymatic
stability of a liquid dishwashing composition. Other suitable solvents include lower
alkanols, diols, other polyols, ethers, amines, and the like may be used in the present
invention. Particularly preferred are the C1-C4 alkanols.
[0048] Other suitable solvents are glycols or alkoxylated glycols, ethers and diethers having
from 4 to 14 carbon atoms, preferably from 6 to 12 carbon atoms, alkoxylated aromatic
alcohols, aromatic alcohols, aliphatic branched alcohols, alkoxylated aliphatic branched
alcohols, alkoxylated linear C1-C5 alcohols, linear C1-C5 alcohols, C8-C14 alkyl and
cycloalkyl hydrocarbons and halo hydrocarbons, C6-C16 glycol ethers and mixtures thereof.
Suitable alkoxylated glycols are methoxy octadecanol and/or ethoxyethoxyethanol, a
suitable aromatic alcohol is benzyl alcohol, suitable aliphatic branched alcohol are
2-ethylbutanol and/or 2-methylbutanol, suitable alkoxylated aliphatic branched alcohols
include 1-methylpropoxyethanol and/or 2-methylbutoxyethanol and suitable linear C
1-C
5 alcohols are methanol, ethanol, propanol or mixtures thereof.
[0049] Other suitable solvents include, but are not limited to, butyl diglycol ether (BDGE),
butyltriglycol ether, ter amilic alcohol and the like.
[0050] Besides propylene glycol,polypropylene glycol and the diols illustrated above, other
glycols according to the formula: HO-CR1R2-OH wherein R1 and R2 are independently
H or a C2-C10 saturated or unsaturated aliphatic hydrocarbon chain and/or cyclic are
suitable and can be used herein. One such suitable glycol is dodecaneglycol.
[0051] Other suitable solvents for use herein include propylene glycol derivatives such
as n-butoxypropanol or n- butoxypropoxypropanol, water-soluble CARBITOL R solvents
or water-soluble CELLOSOLVE R solvents; water-soluble CARBITOL R solvents are compounds
of the 2-(2-alkoxyethoxy)ethanol class wherein the alkoxy group is derived from ethyl,
propyl or butyl; a preferred water-soluble carbitol is 2-(2-butoxyethoxy)ethanol also
known as butyl carbitol. Water-soluble CELLOSOLVE R solvents are compounds of the
2-alkoxyethoxy ethanol class, with 2-butoxyethoxyethanol being preferred. Other suitable
solvents include benzyl alcohol, and diols such as 2-ethyl-1, 3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol
and mixtures thereof. Some preferred solvents for use herein are n-butoxypropoxypropanol,
BUTYL CARBITOL Ò and mixtures thereof. The solvents can also be selected from the
group of compounds comprising ether derivatives of mono-, di- and tri-ethylene glycol,
butylene glycol ethers, and mixtures thereof. The molecular weights of these solvents
are preferably less than 350, more preferably between 100 and 300, even more preferably
between 115 and 250. Examples of preferred solvents include, for example, mono-ethylene
glycol n-hexyl ether, mono-propylene glycol n-butyl ether, and tripropylene glycol
methyl ether. Ethylene glycol and propylene glycol ethers are commercially available
from the Dow Chemical Company under the tradename "Dowanol" and from the Arco Chemical
Company under the tradename "Arcosolv". Other preferred solvents including mono- and
di-ethylene glycol n-hexyl ether are available from the Union Carbide company.
[0052] When present the composition will preferably contain at least 0.01 %, more preferably
at least 0.5%, even more preferably still, at least 1% by weight of the composition
of solvent. The composition will also preferably contain no more than 20%, more preferably
no more than 10%, even more preferably, no more than 8% by weight of the composition
of solvent.
[0053] These solvents may be used in conjunction with an aqueous liquid carrier, such as
water, or they may be used without any aqueous liquid carrier being present. Solvents
are broadly defined as compounds that are liquid at temperatures of 20°C-25°C and
which are not considered to be surfactants. One of the distinguishing features is
that solvents tend to exist as discrete entities rather than as broad mixtures of
compounds.
Diamines
[0054] Another optional although preferred ingredient of the compositions according to the
present invention is a diamine. In the context of a hand dishwashing composition,
the "usage levels" of such diamine in the compositions herein can vary depending not
only on the type and severity of the soils and stains, but also on the wash water
temperature, the volume of wash water and the length of time the dishware is contacted
with the wash water.
[0055] Since the habits and practices of the users of detergent compositions show considerable
variation, the composition will preferably contain at least 0.1%, more preferably
at least 0.2%, even more preferably, at least 0.25%, even more preferably still, at
least 0.5% by weight of said composition of diamine. The composition will also preferably
contain no more than 15%, more preferably no more than 10%, even more preferably,
no more than 6%, even more preferably, no more than 5%, even more preferably still,
no more than about 1.5% by weight of said composition of diamine.
[0056] It is preferred that the diamines used in the present invention are substantially
free from impurities. That is, by "substantially free" it is meant that the diamines
are over 95% pure, i.e., preferably 97%, more preferably 99%, still more preferably
99.5%, free of impurities. Examples of impurities which may be present in commercially
supplied diamines include 2-Methyl-1,3-diaminobutane and alkylhydropyrimidine. Further,
it is believed that the diamines should be free of oxidation reactants to avoid diamine
degradation and ammonia formation.
[0057] Preferred organic diamines are those in which pK1 and pK2 are in the range of 8.0
to 11.5, preferably in the range of 8.4 to 11, even more preferably from 8.6 to 10.75.
Preferred materials for performance and supply considerations are 1,3-bis(methylamine)-cyclohexane
(pKa=10 to 10.5), 1,3 propane diamine (pK1=10.5; pK2=8.8), 1,6 hexane diamine (pK1=11;
pK2=10), 1,3 pentane diamine (Dytek EP) (pK1=10.5; pK2=8.9), 2-methyl 1,5 pentane
diamine (Dytek A) (pK1=11.2; pK2=10.0). Other preferred materials are the primary/primary
diamines with alkylene spacers ranging from C4 to C8. In general, it is believed that
primary diamines are preferred over secondary and tertiary diamines.
[0058] Definition of pK1 and pK2 - As used herein, "pKa1" and "pKa2" are quantities of a type collectively known to
those skilled in the art as "pKa". pKa is used herein in the same manner as is commonly
known to people skilled in the art of chemistry. Values referenced herein can be obtained
from literature, such as from "
Critical Stability Constants: Volume 2, Amines" by Smith and Martel, Plenum Press,
NY and London, 1975. Additional information on pKa's can be obtained from relevant company literature,
such as information supplied by Dupont, a supplier of diamines.
[0059] As a working definition herein, the pKa of the diamines is specified in an all-aqueous
solution at 25°C and for an ionic strength between 0.1 to 0.5 M. The pKa is an equilibrium
constant which can change with temperature and ionic strength; thus, values reported
in the literature are sometimes not in agreement depending on the measurement method
and conditions. To eliminate ambiguity, the relevant conditions and/or references
used for pKa's of this invention are as defined herein or in "Critical Stability Constants:
Volume 2, Amines". One typical method of measurement is the potentiometric titration
of the acid with sodium hydroxide and determination of the pKa by suitable methods
as described and referenced in "
The Chemist's Ready Reference Handbook" by Shugar and Dean, McGraw Hill, NY, 1990.
[0060] It has been determined that substituents and structural modifications that lower
pK1 and pK2 to below 8.0 are undesirable and cause losses in performance. This can
include substitutions that lead to ethoxylated diamines, hydroxy ethyl substituted
diamines, diamines with oxygen in the beta (and less so gamma) position to the nitrogen
in the spacer group (e.g., Jeffamine EDR 148). In addition, materials based on ethylene
diamine are unsuitable.
[0061] The diamines useful herein can be defined by the following structure:

wherein R
2-5 are independently selected from H, methyl, -CH
3CH
2, and ethylene oxides; C
x and C
v are independently selected from methylene groups or branched alkyl groups where x+y
is from 3 to 6; and A is optionally present and is selected from electron donating
or withdrawing moieties chosen to adjust the diamine pKa's to the desired range. If
A is present, then x and y must both be 1 or greater.
[0062] Examples of preferred diamines can be found in the copending provisional patent application
of Phillip Kyle Vinson et al., entitled "Dishwashing Detergent Compositions Containing
Organic Diamines for Improved Grease Cleaning, Sudsing, Low Temperature Stability
and Dissolution", having P & G Case No. 7167P, application serial no. 60/087,693,
and filed on June 2, 1998, which is hereby incorporated by reference.
Carboxylic Acid
[0063] The compositions according to the present invention may comprise a linear or cyclic
carboxylic acid or salt thereof. Where the acid or salt thereof is present and is
linear, it preferably comprises from 1 to 6 carbon atoms whereas where the acid is
cyclic, it preferably comprises greater than 3 carbon atoms. The linear or cyclic
carbon-containing chain of the carboxylic acid or salt thereof may be substituted
with a substituent group selected from the group consisting of hydroxyl, ester, ether,
aliphatic groups having from 1 to 6, more preferably 1 to 4 carbon atoms and mixtures
thereof
[0064] The carboxylic acids or salts thereof preferably have a pKa1 of less than 7, more
preferably from 1 to 3. The carboxylic acid and salts thereof may comprise one or
two or more carboxylic groups.
[0065] Preferred carboxylic acids are those selected from the group consisting of salicylic
acid, maleic acid, acetyl salicylic acid, 3 methyl salicylic acid, 4 hydroxy isophthalic
acid, dihydroxyfumaric acid, 1,2, 4 benzene tricarboxylic acid, pentanoic acid and
salts thereof and mixtures thereof. Where the carboxylic acid exists in the salt form,
the cation of the salt is preferably selected from alkali metal, alkaline earth metal,
monoethanolamine, diethanolamine or triethanolamine and mixtures thereof.
[0066] The carboxylic acid or salt thereof is preferably present at the level of from 0.1%
to 5%, more preferably from 0.2% to 1% and most preferably from 0.25% to 0.5%.
Polymeric Suds Stabilizer
[0067] The compositions of the present invention may optionally contain a polymeric suds
stabilizer. These polymeric suds stabilizers provide extended suds volume and suds
duration without sacrificing the grease cutting ability of the liquid detergent compositions.
These polymeric suds stabilizers are selected from:
- i) homopolymers of (N,N-dialkylamino)alkyl acrylate esters having the formula:

wherein each R is independently hydrogen, C1-C8 alkyl, and mixtures thereof, R1 is hydrogen, C1-C6 alkyl, and mixtures thereof, n is from 2 to 6; and
- ii) copolymers of (i) and

wherein R1 is hydrogen, C1-C6 alkyl, and mixtures thereof, provided that the ratio of (ii) to
(i) is from 2 to 1 to 1 to 2; The molecular weight of the polymeric suds boosters,
determined via conventional gel permeation chromatography, is from 1,000 to 2,000,000,
preferably from 5,000 to 1,000,000, more preferably from 10,000 to 750,000, more preferably
from 20,000 to 500,000, even more preferably from 35,000 to 200,000. The polymeric
suds stabilizer can optionally be present in the form of a salt, either an inorganic
or organic salt, for example the citrate, sulfate, or nitrate salt of (N,N-dimethylamino)alkyl
acrylate ester.
[0068] One preferred polymeric suds stabilizer is (N,N-dimethylamino)alkyl acrylate esters,
namely

[0069] When present in the compositions, the polymeric suds booster may be present in the
composition from 0.01% to 15%, preferably from 0.05% to 10%, more preferably from
0.1% to 5%, by weight.
Builder
[0070] The compositions according to the present invention may further comprise a builder
system. Because builders such as citric acid and citrates impair the stability of
enzymes, it is desirable to include reduce the amounts or completely remove the builder
salts normally utilized in LDL compositions incorporating propylene glycol as a builder.
When a detergent composition includes propylene glycol solvent as a part or a whole
of the detergent's carrier, enzymes are more stable and smaller amounts or no builder
salts are needed.
[0071] If it is desirable to use a builder, then any conventional builder system is suitable
for use herein including aluminosilicate materials, silicates, polycarboxylates and
fatty acids, materials such as ethylene-diamine tetraacetate, metal ion sequestrants
such as aminopolyphosphonates, particularly ethylenediamine tetramethylene phosphonic
acid and diethylene triamine pentamethylene-phosphonic acid. Though less preferred
for obvious environmental reasons, phosphate builders can also be used herein.
[0072] Suitable polycarboxylates builders for use herein include citric acid, preferably
in the form of a water-soluble salt, derivatives of succinic acid of the formula R-CH(COOH)CH
2(COOH) wherein R is C
10-20 alkyl or alkenyl, preferably C
12-16, or wherein R can be substituted with hydroxyl, sulfo sulfoxyl or sulfone substituents.
Specific examples include lauryl succinate, myristyl succinate, palmityl succinate
2-dodecenylsuccinate, 2-tetradecenyl succinate. Succinate builders are preferably
used in the form of their water-soluble salts, including sodium, potassium, ammonium
and alkanolammonium salts.
[0073] Other suitable polycarboxylates are oxodisuccinates and mixtures of tartrate monosuccinic
and tartrate disuccinic acid such as described in
US 4,663,071.
[0074] Especially for the liquid execution herein, suitable fatty acid builders for use
herein are saturated or unsaturated C
10-18 fatty acids, as well as the corresponding soaps. Preferred saturated species have
from 12 to 16 carbon atoms in the alkyl chain. The preferred unsaturated fatty acid
is oleic acid. Other preferred builder system for liquid compositions is based on
dodecenyl succinic acid and citric acid.
[0075] If detergency builder salts are included, they will be included in amounts of from
0.5 % to 50 % by weight of the composition preferably from 5% to 30% and most usually
from 5% to 25% by weight.
Enzymes
[0076] Detergent compositions of the present invention may further comprise one or more
enzymes which provide cleaning performance benefits. Said enzymes include enzymes
selected from cellulases, hemicellulases, peroxidases, proteases, gluco-amylases,
amylases, lipases, cutinases, pectinases, xylanases, reductases, oxidases, phenoloxidases,
lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, β-glucanases,
arabinosidases or mixtures thereof. A preferred combination is a detergent composition
having a cocktail of conventional applicable enzymes like protease, amylase, lipase,
cutinase and/or cellulase. Enzymes when present in the compositions, at from 0.0001%
to 5% of active enzyme by weight of the detergent composition. Preferred proteolytic
enzymes, then, are selected from the group consisting of Alcalase
® (Novo Industri A/S), BPN', Protease A and Protease B (Genencor), and mixtures thereof.
Protease B is most preferred. Preferred amylase enzymes include TERMAMYL
®, DURAMYL
® and the amylase enzymes those described in
WO 9418314 to Genencor International and
WO 9402597 to Novo.
[0077] Further non-limiting examples of suitable and preferred enzymes are disclosed in
the copending application: "Dishwashing Detergent Compositions Containing Organic
Diamines for Improved Grease Cleaning, Sudsing, Low temperature stability and Dissolution",
having P & G Case No. 7167P and application serial no. 60/087,693, which is hereby
incorporated by reference.
[0078] Because hydrogen peroxide and builders such as citric acid and citrates impair the
stability of enzymes in LDL compositions, it is desirable to reduce or eliminate the
levels of these compounds in compositions which contain enzymes. Hydrogen peroxide
is often found as an impurity in surfactants and surfactant pastes. As such, the preferred
level of hydrogen peroxide in the amine oxide or surfactant paste of amine oxide is
0-40 ppm, more preferably 0-15 ppm. Amine impurities in amine oxide and betaines,
if present, should be minimized to the levels referred above for hydrogen peroxide.
Magnesium ions
[0079] While it is preferred that divalent ions be omitted from compositions prepared according
to the present invention, alternate embodiments of the present invention may include
magnesium ions.
[0080] If they are to be included in an embodiment of the present compositions, then the
magnesium ions are present at an active level of from 0.01 % to 1.5 %, preferably
from 0.015 % to 1%, more preferably from 0.025 % to 0.5 %, by weight.
[0081] Preferably, the magnesium ions are added as a hydroxide, chloride, acetate, sulfate,
formate, oxide or nitrate salt to the compositions of the present invention. Because
during storage, the stability of these compositions becomes poor due to the formation
of hydroxide precipitates in the presence of compositions containing moderate concentrations
of hydroxide ions, it may be necessary to add certain chelating agents. Suitable chelating
agents are discussed further below and in
U.S. Pat. No. 5,739,092, issued April 14, 1998, to Ofosu-asante, incorporated herein by reference.
Chelating Agents
[0082] 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.
[0083] Amino carboxylates useful as optional chelating agents include ethylenediaminetetrace-tates,
N-hydroxyethylethylenediaminetriacetates, nitrilo-tri-acetates, ethylenediamine tetrapro-prionates,
triethylenetetraaminehexacetates, diethylenetriaminepentaacetates, and ethanoldi-glycines,
alkali metal, ammonium, and substituted ammonium salts therein and mixtures therein.
[0084] Amino phosphonates are also suitable for use as chelating agents in the compositions
of the invention when at lease low levels of total phosphorus are permitted in detergent
compositions, and include ethylenediaminetetrakis (methylenephosphonates) as DEQUEST.
Preferred, these amino phosphonates to not contain alkyl or alkenyl groups with more
than 6 carbon atoms.
[0087] The compositions herein may also contain water-soluble methyl glycine diacetic acid
(MGDA) salts (or acid form) as a chelant or co-builder. Similarly, the so-called "weak"
builders such as citrate can also be used as chelating agents.
[0088] If utilized, these chelating agents will generally comprise from 0.00015% to 15%
by weight of the detergent compositions herein. More preferably, if utilized, the
chelating agents will comprise from 0.0003% to 3.0% by weight of such compositions.
[0089] Other Ingredients - The detergent compositions will further preferably comprise one or more detersive
adjuncts selected from the following: soil release polymers, polysaccharides, abrasives,
bactericides and other antimicrobials, tarnish inhibitors, builders, enzymes, dyes,
buffers, antifungal or mildew control agents, insect repellents, perfumes, hydrotropes,
thickeners, processing aids, suds boosters, brighteners, anti-corrosive aids, stabilizers
antioxidants and chelants. A wide variety of other ingredients useful in detergent
compositions can be included in the compositions herein, including other active ingredients,
carriers, hydrotropes, antioxidants, processing aids, dyes or pigments, solvents for
liquid formulations, solid fillers for bar compositions, etc. If high sudsing is desired,
suds boosters such as the C
10-C
16 alkanolamides can be incorporated into the compositions, typically at 1%-10% levels.
The C
10-C
14 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.
[0090] An antioxidant can be optionally added to the detergent compositions of the present
invention. They can be any conventional antioxidant used in detergent compositions,
such as 2,6-di-tert-butyl-4-methylphenol (BHT), carbamate, ascorbate, thiosulfate,
monoethanolamine(MEA), diethanolamine, triethanolamine, etc. It is preferred that
the antioxidant, when present, be present in the composition from 0.001% to 5% by
weight.
[0091] 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.
[0092] 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 C
13-15 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,
including liquid laundry detergent compositions.
[0093] Further, these hand dishwashing detergent embodiments preferably further comprises
a hydrotrope. Suitable hydrotropes include sodium, potassium, ammonium or water-soluble
substituted ammonium salts of toluene sulfonic acid, naphthalene sulfonic acid, cumene
sulfonic acid, xylene sulfonic acid.
Non-Aqueous Liquid Detergents
[0094] The manufacture of liquid detergent compositions which comprise a non-aqueous carrier
medium can be prepared according to the disclosures of
U.S. Patents 4,753,570;
4,767,558;
4,772,413;
4,889,652;
4,892,673;
GB-A-2,158,838;
GB-A-2,195,125;
GB-A-2,195,649;
U.S. 4,988,462;
U.S. 5,266,233;
EP-A-225,654 (6/16/87);
EP-A-510,762 (10/28/92);
EP-A-540,089 (5/5/93);
EP-A-540,090 (5/5/93);
U.S. 4,615,820;
EP-A-565,017 (10/13/93);
EP-A-030,096 (6/10/81), incorporated herein by reference. Such compositions can contain various particulate
detersive ingredients stably suspended therein. Such non-aqueous compositions thus
comprise a LIQUID PHASE and, optionally but preferably, a SOLID PHASE, all as described
in more detail hereinafter and in the cited references.
Process of Cleaning Dishware
[0095] The dishware is contacted with a composition as described above. The composition
may be applied to the dishware neat or in dilute form. Thus the dishware may be cleaned
singly by applying the composition to the dishware or the cleaning implement e.g.
sponge or cloth, and optionally, but preferably, subsequently rinsing before drying.
Alternatively, the composition can be mixed with water in a suitable vessel, for example
a basin, sink or bowl and thus a number of dishes can be cleaned using the same composition
and water (dishwater). In a further alternative process the product can be used in
dilute form in a suitable vessel as a soaking medium for, typically extremely dirty,
dishware. As before the dishware can be optionally, although preferably, rinsed before
allowing to dry. Drying make take place passively by allowing for the natural evaporation
of water or actively using any suitable drying equipment, for example a cloth or towel.