Patent Application
20110143990
The present disclosure relates to laundry detergent compositions, including but not limited to those in liquid and gel forms, containing amphiphilic graft polymers based upon water-soluble polyalkylene oxides.
Consumers desire laundry detergents including, but not limited to those in liquid and gel forms, that provide excellent overall cleaning. The detergent industry typically utilizes surfactants, among other things, to deliver this benefit. Due to increasing environmental sensitivity, as well as rising cost, the wide spread use of surfactants may be losing favor. Consequently, detergent manufacturers are examining ways to reduce the dosage of surfactant in the wash liquor, while still providing the consumer with excellent overall cleaning.
One approach for reducing surfactant dosage is to formulate laundry detergents with polymers. Like surfactants, polymers may be useful as releasers of soil from fabric. In addition, or in the alternative, some polymers may provide for suspension of soils dispersed in the wash liquor, which in turn may prevent their deposition back onto the fabrics being washed. However, some of these polymers may lose at least a portion of their efficacy when combined with the surfactants that they are meant to, at least in part, replace.
It would therefore be desirable to provide laundry detergent compositions comprising polymers that provide for good suspension of soils, such as greasy soils and the like, even in the presence of surfactants. Such laundry detergent compositions would provide for good cleaning even when formulated with low levels of surfactants and organic solvents. It would be also desirable to provide such laundry detergent compositions with multiple polymer systems that further provide for both good soil suspension and soil removal. Such a detergent composition would particularly be desirable if used in conjunction with fabric softeners, such as cationic coacervating polymers for example, which may drive deposition of soils onto fabrics. Moreover, it would also be desirable to provide these laundry detergent compositions in forms such as liquids, gels and combinations thereof.
Graft copolymers based on polyalkylene oxides and vinyl esters have previously been described in, for example, EP 0219048A, EP 0358474B1, WO 2006/130442A1, WO 2007/138054A1. These amphiphilic graft polymers provide hydrophobic soil suspension which provides a cleaning benefit for laundry detergents. Surprisingly, it has been found that by incorporating these polymers into laundry detergent compositions, overall surfactant levels may be reduced, yet the general cleaning capability of the resulting detergent is substantially the same, if not better. This may particularly be the case in detergent compositions comprising surfactant systems having high levels of anionic surfactant including, but not limited to, linear alkylbenzene sulfonic acid. Without wishing to be bound by theory, it is believed that the amphiphilic graft polymers may disrupt micelles and/or vesicles that are formed in the wash liquor between calcium ions and anionic surfactant; the anionic surfactant that would otherwise be “bound” within the micelle/vesicles is thereby made available for cleaning. It has also been surprisingly found that levels of organic solvent may also be reduced, without negatively impacting general cleaning capability. The resulting laundry detergent compositions are disclosed in detail below.
It has also been found that the use of the amphiphilic graft polymers provide further improved cleaning performance when they are incorporated in a multiple polymer system. Polymers such as ethoxysulfated hexamethylene diamine dimethyl quat and the like may be utilized in laundry detergent compositions as hydrophilic stain or soil removers. However, their efficacy may be reduced due to the presence (in the wash liquor and/or on fabric surfaces) of fabric softeners and/or perfume adjuncts including, but not limited to, cationic coacervating polymers. Without being bound by theory, it is believed that the cationic coacervating polymers act as deposition aids and thereby can interfere and/or negate the affects of the hydrophilic stain removers. Yet it has surprisingly been found that by utilizing the aforementioned, new amphiphilic graft polymers in conjunction with polymeric, hydrophilic soil removers, little or no reduction in hydrophilic stain removal is observed. In some embodiments, the optimal weight percentage ratio of amphiphilic graft polymer to ethoxylated hexamethylene diamine dimethyl quat is from about 95:5 to about 10:90, from about 90:10 to about 20:80, or from about 80:20 to about 50:50.
Thus in some embodiments, the present laundry detergent compositions comprise copolymers obtainable by grafting a polyalkylene oxide of number average molecular weight from about 2,000 to about 100,000 with vinyl acetate, which may be partially saponified, in a weight ratio of polyalkylene oxide to vinyl acetate of 1:0.2 to 1:10.
In other embodiments, the present laundry detergent compositions comprise: (a) amphiphilic graft polymer based on water-soluble polyalkylene oxides as a graft base and side chains formed by polymerization of a vinyl ester component; this polymer has an average of less than or equal to one graft site per 50 alkylene oxide units and a mean molar mass of from about 3,000 to about 100,000 and may have a polydispersity of less than or equal to about 3; (b) from about 0.2% to about 8% by weight of organic solvent; and (c) from about 2% to about 40% of a surfactant system.
In further embodiments, the present laundry detergent compositions may comprise a multiple polymer system comprising only two polymers. The two polymer system may in turn comprise a first polymer which acts as a hydrophilic soil remover and a second polymer which acts as a hydrophobic soil suspender. The hydrophobic soil suspender may be an amphiphilic graft polymer as described above. The hydrophilic soil remover may be a polyalkoxylated cationic or zwitterionic polymer having a backbone comprising oligoamine, polyamine, or polyimine; and at least one polyalkoxylated side chain.
Any of the presently disclosed laundry detergent compositions may be in a form selected from: liquid; gel; and mixtures thereof. Moreover, the compositions may be isotropic, anisotropic or combinations thereof.
“Soil” and “stain” are used interchangeably herein.
“Fabric’ and “textile” are used interchangeably herein.
“Liquid detergent composition” as used herein, refers to compositions that are in a form selected from the group of: “pourable liquid”; “gel”; “cream”; and combinations thereof. The liquid detergent compositions may be anisotropic, isotropic and combinations thereof.
“Pourable liquid” as defined herein refers to a liquid having a viscosity of less than about 2000 mPa*s at 25° C. and a shear rate of 20 sec-1. In some embodiments, the viscosity of the pourable liquid may be in the range of from about 200 to about 1000 mPa*s at 25° C. at a shear rate of 20 sec-1. In some embodiments, the viscosity of the pourable liquid may be in the range of from about 200 to about 500 mPa*s at 25° C. at a shear rate of 20 sec-1.
“Gel” as defined herein refers to a transparent or translucent liquid having a viscosity of greater than about 2000 mPa*s at 25° C. and at a shear rate of 20 sec-1. In some embodiments, the viscosity of the gel may be in the range of from about 3000 to about 10,000 mPa*s at 25° C. at a shear rate of 20 sec-1 and greater than about 5000 mPa*s at 25° C. at a shear rate of 0.1 sec-1.
“Cream” and “paste” are used interchangeably and as defined herein refer to opaque liquid compositions having a viscosity of greater than about 2000 mPa*s at 25° C. and a shear rate of 20 sec-1. In some embodiments, the viscosity of the cream may be in the range of from about 3000 to about 10,000 mPa*s at 25° C. at a shear rate of 20 sec-1, or greater than about 5000 mPa*s at 25° C. at a shear rate of 0.1 sec-1.
“Liquid matrix” and “liquid carrier” are used interchangeably herein.
The articles “a”, “an” and “the” as used herein refer to “one or more”, unless otherwise indicated.
Markush language as used herein encompasses combinations of the individual Markush group members, unless otherwise indicated.
All percentages, ratios and proportions used herein are by weight percent of the composition, unless otherwise specified. All average values are calculated “by weight” of the composition or components thereof, unless otherwise expressly indicated.
Mole percent (mol %) as used herein may mean either the percent of a monomeric unit in relation to all monomeric units of the polymer; or the mole fraction of reagents or reactants based upon other reagents or reactants.
All numerical ranges disclosed herein, are meant to encompass each individual number within the range and to encompass any combination of the disclosed upper and lower limits of the ranges.
The present laundry detergent compositions address the aforementioned problems, among others, through the selection of: (1) amphiphilic graft polymer; (2) a surfactant system; (3) liquid matrix (organic solvent). Additional components may be added to the laundry detergent compositions including, but not limited to: (4) structurant; (5) hydrotrope; (6) soil suspension and/or release polymer; and (7) fabric softener.
The graft copolymers useful in the compositions of the present invention are described and claimed in EP 0219048A. They are obtainable by grafting a polyalkylene oxide of number average molecular weight from about 2,000 to about 100,000 with vinyl acetate, which may be partially saponified, in a weight ratio of polyalkylene oxide to vinyl acetate of about 1:0.2 to about 1:10. The vinyl acetate may, for example, be saponified to an extent of up to 15%. The polyalkylene oxide may contain units of ethylene oxide, propylene oxide and/or butylene oxide. Selected embodiments comprise ethylene oxide.
In some embodiments the polyalkylene oxide has a number average molecular weight of from about 4,000 to about 50,000, and the weight ratio of polyalkylene oxide to vinyl acetate is from about 1:0.5 to about 1:6. A material within this definition, based on polyethylene oxide of molecular weight 6,000 (equivalent to 136 ethylene oxide units), containing approximately 3 parts by weight of vinyl acetate units per 1 part by weight of polyethylene oxide, and having itself a molecular weight of about 24,000, is commercially available from BASF as Sokalan™ HP22. The polymers are present in the compositions of the invention in amounts of from about 0.1% to about 3%, by weight of the compositions.
Selected embodiments of the graft copolymer amphiphilic graft polymers for use in the present invention as well as methods of making them are described in detail in PCT Patent Application No. WO 2007/138054. They may be present in the liquid detergent compositions at weight percentages of from about 0.05% to about 10%, from about 0.1% to about 5%, from about 0.2% to about 3%, or from about 0.3% to about 2%. The amphiphilic graft polymers are found to provide excellent hydrophobic soil suspension even in the presence of cationic coacervating polymers.
The amphiphilic graft polymers are based on water-soluble polyalkylene oxides as a graft base and side chains formed by polymerization of a vinyl ester component. These polymers having an average of less than or equal to one graft site per 50 alkylene oxide units and mean molar masses (Mw) of from about 3000 to about 100,000.
One method of preparing the amphiphilic graft polymers comprises the steps of: polymerizing a vinyl ester component (B) composed of vinyl acetate and/or vinyl propionate (B1) and, if desired, a further ethylenically unsaturated monomer (B2), in the presence of a water-soluble polyalkylene oxide (A), a free radical-forming initiator (C) and, if desired, up to 40% by weight, based on the sum of components (A), (B) and (C), of an organic solvent (D), at a mean polymerization temperature at which the initiator (C) has a decomposition half-life of from 40 to 500 min, in such a way that the fraction of unconverted graft monomer (B) and initiator (C) in the reaction mixture is constantly kept in a quantitative deficiency relative to the polyalkylene oxide (A).
Selected embodiments of the graft polymers are characterized by their low degree of branching (degree of grafting); they have, on average, based on the reaction mixture obtained, not more than 1 graft site, preferably not more than 0.6 graft site, more preferably not more than 0.5 graft site and most preferably not more than 0.4 graft site per 50 alkylene oxide units. They comprise, on average, based on the reaction mixture obtained, preferably at least 0.05, in particular at least 0.1 graft site per 50 alkylene oxide units. The degree of branching can be determined, for example, by means of 13C NMR spectroscopy from the integrals of the signals of the graft sites and the —CH2— groups of the polyalkylene oxide.
In accordance with their low degree of branching, the molar ratio of grafted to ungrafted alkylene oxide units in the inventive graft polymers is from about 0.002 to about 0.05, or from about 0.002 to about 0.035, or from about 0.003 to about 0.025, or from about 0.004 to about 0.02.
In some embodiments of the inventive graft polymers feature a narrow molar mass distribution and hence a polydispersity Mw/Mn of generally less than or equal to about 3, or less than or equal to about 2.5, or less than or equal to about 2.3. In some embodiments, their polydispersity Mw/Mn is in the range from about 1.5 to about 2.2. The polydispersity of the graft polymers can be determined, for example, by gel permeation chromatography using narrow-distribution polymethyl methacrylates as the standard.
The mean weight average molecular weight Mw of the inventive graft polymers is from about 3000 to about 100,000, or from about 6000 to about 45,000, or from about 8000 to about 30,000.
Other embodiments of the inventive graft polymers may also have only a low content of ungrafted polyvinyl ester (B). In general, they comprise less than or equal to about 10% by weight, or less than or equal to about 7.5% by weight, or less than or equal to about 5% by weight of ungrafted polyvinyl ester (B).
Owing to the low content of ungrafted polyvinyl ester and the balanced ratio of components (A) and (B), the inventive graft polymers are soluble in water or in water/alcohol mixtures (for example a 25% by weight solution of diethylene glycol monobutyl ether in water). They have pronounced, low cloud points which, for the graft polymers soluble in water at up to 50° C., are generally less than or equal to about 95° C., or less than or equal to about 85° C., or less than or equal to about 75° C., and, for the other graft polymers in 25% by weight diethylene glycol monobutyl ether, generally less than or equal to about 90° C., or from about 45 to about 85° C.
Some embodiments or the inventive amphiphilic graft polymers have:
(A) from about 20 to about 70% by weight of a water-soluble polyalkylene oxide as a graft base and
(B) side chains formed by free-radical polymerization of from about 30 to about 80% by weight of a vinyl ester component composed of:
(B1) from about 70 to 100% by weight of vinyl acetate and/or vinyl propionate and
(B2) from 0 to about 30% by weight of a further ethylenically unsaturated monomer in the presence of (A).
Other embodiments comprise from about 25 to about 60% by weight of the graft base (A) and from about 40 to about 75% by weight of the polyvinyl ester component (B).
Water-soluble polyalkylene oxides suitable for forming the graft base (A) are in principle all polymers based on C2-C4-alkylene oxides which comprise at least about 50% by weight, or at least about 60% by weight, or at least about 75% by weight of ethylene oxide in copolymerized form.
Some embodiments of the polyalkylene oxides (A) may have a low polydispersity, Mw/Mn. In some embodiments the polydispersity is less than or equal to about 1.5.
The polyalkylene oxides (A) may be the corresponding polyalkylene glycols in free form, i.e. with OH end groups, but they may also be capped at one or both end groups. Suitable end groups are, for example, C1-C25-alkyl, phenyl and C1-C14-alkylphenyl groups.
Non-limiting examples of particularly suitable polyalkylene oxides (A) include:
(A1) polyethylene glycols which may be capped at one or both end groups, especially by C1-C25-alkyl groups, but are preferably not etherified, and have mean molar masses Mn of preferably from about 1500 to about 20,000, or from about 2500 to about 15,000;
(A2) copolymers of ethylene oxide and propylene oxide and/or butylene oxide with an ethylene oxide content of at least about 50% by weight, which may likewise be capped at one or both end groups, for example by C1-C25-alkyl groups, but are not etherified, and have mean molar masses Mn of from about 1500 to about 20,000, or from about 2500 to about 15,000;
(A3) chain-extended products having mean molar masses of from about 2500 to about 20,000, which are obtainable by reacting polyethylene glycols (A1) having mean molar masses Mn of from about 200 to about 5000 or copolymers (A2) having mean molar masses Mn of from about 200 to about 5000 with C2-C12-dicarboxylic acids or -dicarboxylic esters or C6-C18-diisocyanates. In some embodiments, the graft bases (A) are polyethylene glycols (A1). The side chains of the inventive graft polymers are formed by polymerization of a vinyl ester component (B) in the presence of the graft base (A).
The vinyl ester component (B) may comprise of (B1) vinyl acetate or vinyl propionate or of mixtures of vinyl acetate and vinyl propionate. In some embodiments some preference may be given to vinyl acetate as the vinyl ester component (B).
However, the side chains of the graft polymer can also be formed by copolymerizing vinyl acetate and/or vinyl propionate (B1) and a further ethylenically unsaturated monomer (B2). The fraction of monomer (B2) in the vinyl ester component (B) may be up to about 30% by weight, which corresponds to a content in the graft polymer of (B2) of about 24% by weight.
Suitable comonomers (B2) are, for example, monoethylenically unsaturated carboxylic acids and dicarboxylic acids and their derivatives, such as esters, amides and anhydrides, and styrene. It is of course also possible to use mixtures of different comonomers.
Specific, non-limiting examples include (meth)acrylic acid, C1-C12-alkyl and hydroxy-C2-C12-alkyl esters of (meth)acrylic acid, (meth)acrylamide, N—C1-C12-alkyl(meth)acrylamide, N,N-di(C1-C6-alkyl)(meth)acrylamide, maleic acid, maleic anhydride and mono(C1-C12-alkyl)esters of maleic acid.
Some monomers (B2) are the C1-C8-alkyl esters of (meth)acrylic acid and hydroxyethyl acrylate. In some embodiments particular preference may be given to C1-C4-alkyl esters of (meth)acrylic acid. Some embodiment may use methyl acrylate, ethyl acrylate, or n-butyl acrylate. When the inventive graft polymers comprise the monomers (B2) as a constituent of the vinyl ester component (B), the content of graft polymers in (B2) may be from about 0.5 to about 20% by weight, or from about 1 to about 15% by weight, or from about 2 to about 10% by weight.
Without intending to be limited by theory, it is believed that the amphiphilic graft polymers operate by co-micellization with the surfactants.
Any suitable surfactant system may be of use in the present invention. The surfactant system may be present in the liquid detergent compositions at weight percentages of from about 2% to about 40%, from about 5% to about 30%, or from about 10% to about 25%. Surfactant that may be used for the present invention may comprise a surfactant or surfactant system comprising surfactants selected from nonionic, anionic, cationic surfactants, ampholytic, zwitterionic, semi-polar nonionic surfactants, other adjuncts such as alkyl alcohols, or mixtures thereof.
Nonlimiting examples of anionic surfactants useful herein include: C8-C18 alkyl benzene sulfonates (LAS); C10-C20 primary, branched-chain and random alkyl sulfates (AS); C10-C18 secondary (2,3) alkyl sulfates; C10-C18 alkyl alkoxy sulfates (AExS) wherein preferably x is from 1-30; C10-C18 alkyl alkoxy carboxylates preferably comprising 1-5 ethoxy units; mid-chain branched alkyl sulfates as discussed in U.S. Pat. No. 6,020,303 and U.S. Pat. No. 6,060,443; mid-chain branched alkyl alkoxy sulfates as discussed in U.S. Pat. No. 6,008,181 and U.S. Pat. No. 6,020,303; modified alkylbenzene sulfonate (MLAS) as discussed in WO 99/05243, WO 99/05242, and WO 99/05244; methyl ester sulfonate (MES); and alpha-olefin sulfonate (AOS).
Non-limiting examples of nonionic co-surfactants include: C12-C18 alkyl ethoxylates, such as, NEODOL® nonionic surfactants from Shell and LUTENSOL® XL and LUTENSOL® XP from BASF; C6-C12 alkyl phenol alkoxylates wherein the alkoxylate units are a mixture of ethoxy and propoxy units; C12-C18 alcohol and C6-C12 alkyl phenol condensates with ethylene oxide/propylene oxide block alkyl polyamine ethoxylates such as PLURONIC® from BASF; C14-C22 mid-chain branched alcohols, BA, as discussed in U.S. Pat. No. 6,150,322; C14-C22 mid-chain branched alkyl alkoxylates, BAEx, wherein x is from 1-30, as discussed in U.S. Pat. No. 6,153,577, U.S. Pat. No. 6,020,303 and U.S. Pat. No. 6,093,856; Alkylpolysaccharides as discussed in U.S. Pat. No. 4,565,647 Llenado, issued Jan. 26, 1986; specifically alkylpolyglycosides as discussed in U.S. Pat. No. 4,483,780 and U.S. Pat. No. 4,483,779; Polyhydroxy fatty acid amides as discussed in U.S. Pat. No. 5,332,528; and ether capped poly(oxyalkylated) alcohol surfactants as discussed in U.S. Pat. No. 6,482,994 and WO 01/42408.
Non-limiting examples of semi-polar nonionic co-surfactants include: water-soluble amine oxides containing one alkyl moiety of from about 10 to about 18 carbon atoms and 2 moieties selected from the group consisting of alkyl moieties and hydroxyalkyl moieties containing from about 1 to about 3 carbon atoms; water-soluble phosphine oxides containing one alkyl moiety of from about 10 to about 18 carbon atoms and 2 moieties selected from the group consisting of alkyl moieties and hydroxyalkyl moieties containing from about 1 to about 3 carbon atoms; and water-soluble sulfoxides containing one alkyl moiety of from about 10 to about 18 carbon atoms and a moiety selected from the group consisting of alkyl moieties and hydroxyalkyl moieties of from about 1 to about 3 carbon atoms. See WO 01/32816, U.S. Pat. No. 4,681,704, and U.S. Pat. No. 4,133,779.
In some embodiments, surfactant of the detergent products of the present invention includes at least one anionic surfactant and at least one nonionic surfactant. In some embodiments, the detergent products of the present invention may also include other surfactants such as zwitterionic, ampholytic or cationic type or can comprise compatible mixtures of these types in conjunction with the anionic surfactant and nonionic surfactant.
Non-limiting examples of suitable anionic surfactants are selected from: linear alkylbenzene sulfonic acid; branched alkylbenzene sulfonic acid; C12 to C18 alkylsulfate; C12-C18 alkyl alkoxy sulfate; C12-C18 alkyl methyl ester sulfonate and combinations thereof.
Further surfactants useful herein include those described in U.S. Pat. No. 3,664,961, Norris, issued May 23, 1972, U.S. Pat. No. 3,919,678, Laughlin et al., issued Dec. 30, 1975, U.S. Pat. No. 4,222,905, Cockrell, issued Sep. 16, 1980, and in U.S. Pat. No. 4,239,659, Murphy, issued Dec. 16, 1980.
Anionic surfactants which are suitable for use herein include the water-soluble salts, preferably the alkali metal, and ammonium salts, of organic sulfuric reaction products having in their molecular structure an alkyl group containing from about 10 to about 20 carbon atoms and a sulfonic acid or sulfuric acid ester group. (Included in the term “alkyl” is the alkyl portion of acyl groups.) Examples of this group of synthetic surfactants are a) the sodium, potassium and ammonium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C8-C18 carbon atoms) such as those produced by reducing the glycerides of tallow or coconut oil; b) the sodium, potassium and ammonium alkyl polyethoxylate sulfates, particularly those in which the alkyl group contains from about 10 to about 22, or from about 12 to about 18 carbon atoms, and wherein the polyethoxylate chain contains from 1 to about 15, or 1 to about 6 ethoxylate moieties; and c) the sodium and potassium alkylbenzene sulfonates in which the alkyl group contains from about 9 to about 15 carbon atoms, in straight chain or branched chain configuration, e.g., those of the type described in U.S. Pat. Nos. 2,220,099 and 2,477,383. Also useful are linear straight chain alkylbenzene sulfonates in which the average number of carbon atoms in the alkyl group is from about 11 to about 13, abbreviated as C11-13 LAS.
In one embodiment, nonionic surfactants useful herein include those of the formula R1(OC2H4)nOH, wherein R1 is a C10-C16 alkyl group or a C8-C12 alkyl phenyl group, and n is from 3 to about 80. In one embodiment, the nonionic surfactants are condensation products of C12-C15 alcohols with from about 5 to about 20 moles of ethylene oxide per mole of alcohol, e.g., C12-C13 alcohol condensed with about 6.5 moles of ethylene oxide per mole of alcohol.
Additional suitable nonionic surfactants include polyhydroxy fatty acid amides of the formula:
wherein R is a C9-17 alkyl or alkenyl, R1 is a methyl group and Z is glycidyl derived from a reduced sugar or alkoxylated derivative thereof. Examples are N-methyl N-1-deoxyglucityl cocoamide and N-methyl N-1-deoxyglucityl oleamide. Processes for making polyhydroxy fatty acid amides are known and can be found in Wilson, U.S. Pat. No. 2,965,576 and Schwartz, U.S. Pat. No. 2,703,798, the disclosures of which are incorporated herein by reference.
The liquid detergent compositions according to the present invention also contain an aqueous liquid matrix. Generally the amount of the liquid matrix employed in the compositions herein will be relatively large, often comprising the balance of the detergent composition, but can comprise from about 5 wt % to about 85 wt % by weight of the detergent composition. Preferably, the compositions of the present invention comprise from about 20% to about 80% of an aqueous liquid matrix.
The most cost effective type of aqueous, non-surface active liquid matrix is, of course, water itself. Accordingly, the aqueous, non-surface active liquid matrix component will generally be mostly, if not completely, comprised of water. While other types of water-miscible liquids, such as C1-C3 alkanolamines such as mono-, di- and triethanolamines, and the like, have been conventionally been added to liquid detergent compositions as neutralizers, hydrotropes, or stabilizers. Thickeners, if desired, may also be utilized, such as Polygel DKP®, a polyacrylate thickener from ex 3V Co. If utilized, phase stabilizers/co-solvents can comprise from about 0.1% to 5.0% by weight of the compositions herein.
C1-C3 lower alkanols may also be used as organic solvents in the liquid matrices of use in the present invention. The organic solvents that may be used include, but are not limited to, organic solvents that are liquid at room temperature and consist essentially of atoms selected from carbon; hydrogen; oxygen; and combinations thereof. Non-limiting examples of suitable organic solvents include ethanol; 1,2 propanediol; glycerol; diethylene glycol; 2-methyl 1,3 propanediol; and combinations thereof. When used, the solvent may comprise from about 0.2% to about 8%, preferably from about 0.5% to about 5%, by weight of the laundry detergent composition, of an organic solvent
Any suitable structurant may be utilized in the liquid detergent compositions of the present invention. In some embodiments, structurant(s) may be present in the compositions at a weight percentage of from about 0.05% to about 0.8%, or from about 0.1% to about 0.4%.
One type of structuring agent which is especially useful in the compositions of the present invention comprises non-polymeric (except for conventional alkoxylation), crystalline hydroxy-functional materials which can form thread-like structuring systems throughout the liquid matrix when they are crystallized within the matrix in situ. Such materials can be generally characterized as crystalline, hydroxyl-containing fatty acids, fatty esters or fatty waxes. Such materials will generally be selected from those having the following formulas:
wherein:
R1 is
R2 is R1 or H;
R3 is R1 or H;
R4 is independently C10-C22 alkyl or alkenyl comprising at least one hydroxyl group;
wherein:
R4 is as defined above in i);
M is Na+, K+, Mg++ or Al3+, or H; and
Z—(CH(OH))a-Z′ III)
where a is from 2 to 4, preferably 2; Z and Z′ are hydrophobic groups, especially selected from C6-C20 alkyl or cycloalkyl, C6-C24 alkaryl or aralkyl, C6-C20 aryl or mixtures thereof. Optionally Z can contain one or more nonpolar oxygen atoms as in ethers or esters.
Materials of the Formula I type are preferred. They can be more particularly defined by the following formula:
wherein:
(x+a) is from between 11 and 17;
(y+b) is from between 11 and 17; and
(z+c) is from between 11 and 17.
Preferably, in this formula x=y=z=10 and/or a=b=c=5.
Specific examples of preferred crystalline, hydroxyl-containing structurants include castor oil and its derivatives. Examples include mixtures of hydrogenated castor oil and its hydrolysis products, e.g. hydroxy stearic acid. Especially preferred are hydrogenated castor oil derivatives such as hydrogenated castor oil and hydrogenated castor wax. Commercially available, castor oil-based, crystalline, hydroxyl-containing structurants include THIXCIN® from Rheox, Inc. (now Elementis).
Alternative commercially available materials that are suitable for use as crystalline, hydroxyl-containing structurants are those of Formula III hereinbefore. An example of a structurant of this type is 1,4-di-O-benzyl-D-Threitol in the R,R, and S,S forms and any mixtures, optically active or not.
All of these crystalline, hydroxyl-containing structurants as hereinbefore described are believed to function by forming thread-like structuring systems when they are crystallized in situ within the aqueous liquid matrix of the compositions herein or within a pre-mix which is used to form such an aqueous liquid matrix. Such crystallization is brought about by heating an aqueous mixture of these materials to a temperature above the melting point of the structurant, followed by cooling of the mixture to room temperature while maintaining the liquid under agitation.
Under certain conditions, the crystalline, hydroxyl-containing structurants will, upon cooling, form the thread-like structuring system within the aqueous liquid matrix. This thread-like system can comprise a fibrous or entangled thread-like network. Non-fibrous particles in the form of “rosettas” may also be formed. The particles in this network can have an aspect ratio of from 1.5:1 to 200:1, more preferably from 10:1 to 200:1. Such fibers and non-fibrous particles can have a minor dimension which ranges from 1 micron to 100 microns, more preferably from 5 microns to 15 microns.
These crystalline, hydroxyl-containing materials are especially preferred structurants for providing the detergent compositions herein with shear-thinning rheology. They can effectively be used for this purpose at concentrations which are low enough that the compositions are not rendered so undesirably opaque that bead visibility is restricted. These materials and the networks they form also serve to stabilize the compositions herein against liquid-liquid or solid-liquid (except, of course, for the beads and the structuring system particles) phase separation. Their use thus permits the formulator to use less of relatively expensive non-aqueous solvents or phase stabilizers which might otherwise have to be used in higher concentrations to minimize undesirable phase separation. These preferred crystalline, hydroxyl-containing structurants, and their incorporation into aqueous shear-thinning matrices, are described in greater detail in U.S. Pat. No. 6,080,708 and in PCT Publication No. WO 02/40627.
Other types of organic external structurants, besides the non-polymeric, crystalline, hydroxyl-containing structurants described hereinbefore, may be utilized in the liquid detergent compositions herein. Polymeric materials which will provide shear-thinning characteristics to the aqueous liquid matrix may also be employed.
Suitable polymeric structurants include those of the polyacrylate, polysaccharide or polysaccharide derivative type. Polysaccharide derivatives typically used as structurants comprise polymeric gum materials. Such gums include pectine, alginate, arabinogalactan (gum Arabic), carrageenan, gellan gum, xanthan gum and guar gum.
If polymeric structurants are employed herein, a preferred material of this type is gellan gum. Gellan gum is a heteropolysaccharide prepared by fermentation of Pseudomonaselodea ATCC 31461. Gellan gum is commercially marketed by CP Kelco U.S., Inc. under the KELCOGEL tradename. Processes for preparing gellan gum are described in U.S. Pat. Nos. 4,326,052; 4,326,053; 4,377,636 and 4,385,123.
Of course, any other structurants besides the foregoing specifically described materials can be employed in the aqueous liquid detergent compositions herein, provided such other structurant materials produce compositions having the selected rheological characteristics hereinbefore described. Also combinations of various structurants and structurant types may be utilized, again so long as the resulting aqueous matrix of the composition possesses the hereinbefore specified pour viscosity, constant stress viscosity and viscosity ratio values.
In some embodiments the structurants include, but are not limited to, those organic external structurant selected from the group consisting of
Any suitable hydrotrope may be of use in the present detergent compositions. In some embodiments, anionic hydrotropes are utilized and are present at from about 0.1% to about 5%, or from about 0.2% to about 3%, or from about 0.5% to about 2%, by weight of the detergent composition. Suitable anionic hydrotropes may be selected from a sulfonic acid or sodium sulfonate salt of toluene, cumene, xylene, napthalene or mixtures thereof.
Any suitable hydrophilic soil removal polymer or polymers may be of use in the present invention. By hydrophilic soil removal polymer it is meant a polymer which is hydrophilic itself and which acts to help removal and suspension of hydrophilic soils from fabrics. One class of preferred soil removal polymers as used herein are polyalkoxylated, cationic or zwitterionic, polymers having a backbone comprising oligoamine, polyamine, or polyimine; and at least one polyalkoxylated side chain. A suitable soil removal polymer, preferred for the present invention may be selected from the group consisting of:
Another hydrophilic soil removal polymer which may be used in the present invention are polymers comprising polyacrylic acid monomers having a number average molecular weight of from about 1000 to about 10,000 and a polydispersity of less than about 5 as disclosed in PCT Patent Application No. WO2007/149806.
The detergent compositions of the present invention may further comprise fabric softeners. In some embodiments, the fabric softener may comprise cationic coacervating polymers. Cationic coacervating polymers of use in the present invention are selected from: cationic hydroxylethyl cellulose; polyquaternium polymers; and combinations thereof.
The present detergent compositions may have any suitable overall pH. Non-limiting examples of suitable overall pH ranges include from about 6.5 to about 11 or from about 7.5 to about 10. Buffers and neutralizing agents may be utilized in the detergent compositions of the present invention in varying proportions to achieve the desired overall pH. Non-limiting examples of buffers and neutralizers of use include NaOH and lower alkanolamines. Non-limiting examples of useful lower alkanolamines include: monoethanolamine; diethanolamine; and triethanolamine. Note that although the lower alkanolamines could generally be considered as “organic solvents,” for the purpose of clarity in the presently disclosed detergent formulations, all such materials are NOT to be counted as “organic solvents”.
For the purposes of illustration only, and not be construed as limiting, the following examples of the liquid laundry detergent compositions of the present invention are provided below. The laundry detergent compositions may made using any suitable method.
1PEG-PVA graft copolymer is a polyvinyl acetate grafted polyethylene oxide copolymer having a polyethylene oxide backbone and multiple polyvinyl acetate side chains. The PEG-PVA graft copolymer is either Sokalan ™ HP22 or a copolymer where the molecular weight of the polyethylene oxide backbone is about 6000 and the weight ratio of the polyethylene oxide to polyvinyl acetate is about 40 to 60 and no more than 1 grafting point per 50 ethylene oxide units.
2Polyethylenimine (MW = 600) ethoxylated 20 times.
3Reversible Protease inhibitor of structure
1PEG-PVA graft copolymer is a polyvinyl acetate grafted polyethylene oxide copolymer having a polyethylene oxide backbone and multiple polyvinyl acetate side chains. The PEG-PVA graft copolymer is either Sokalan ™ HP22 or a copolymer where the molecular weight of the polyethylene oxide backbone is about 6000 and the weight ratio of the polyethylene oxide to polyvinyl acetate is about 40 to 60 and no more than 1 grafting point per 50 ethylene oxide units.
2Alco 725 (styrene/acrylate)
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. To the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
This application is a continuation of and claims priority under 35 U.S.C. §120 to U.S. application Ser. No. 12/147,886 filed on Jun. 27, 2008. This application claims priority to U.S. Provisional Application Ser. No. 60/937,818, filed Jun. 29, 2007.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12147886 | Jun 2008 | US |
| Child | 13032183 | US |
