WO1996028529A1 - Detergent composition comprising nonionic polysaccharide ether and non-soap anionic surfactant - Google Patents

Abstract

Detergent composition comprising a nonionic polysaccharide ether and a non-soap anionic surfactant, with the ether and the surfactant being in close physical proximity in the detergent composition.

Description

DETERGENT COMPOSITION COMPRISING NONIONIC POLYSACCHARIDE ETHER AND NON-SOAP ANIONIC SURFACTANT.

Field of the Invention

The present invention relates to detergent compositions providing improved soil release performance.

Background of the Invention

During the fabric laundering operation it is highly desirable to provide the fabrics, particularly man-made fabrics produced from synthetic fibres, with soil release properties.

Due to the hydrophobic nature of fabrics composed of partially or completely of synthetic fibres, the removal of greasy soils and stains therefrom is particularly difficult. In order to address this problem, soil release polymers may be incorporated into the detergent composition. During laundering the soil release agents are adsorbed onto the surface of the fabric, thereby reducing the hydrophobicity of the fabric surface. Once the fabric is treated with a soil release agent, the ease of removal of soils and stains from the surface of the fabric is considerably improved.

The main types of soil release agents incorporated into detergent compositions, which provide benefits to primarily hydrophobic synthetic fabrics include synthetic soil release agents, preferably terephthalate based, and polysaccharide ethers. Polysaccharide ether may conventionally characterised by one or more of molecular weight, degree of polymerisation (dp) and degree of substitution (ds). Polysaccharide ethers such as cellulose ethers have been described for example in GB 1 534 641 , which discloses nonionic surfactant detergent compositions comprising cellulose ether soil release agents such as alkyl and hydroxyalkyl cellulose ethers.

Numerous disclosures of detergent compositions comprising cellulose ethers and optionally anionic surfactants exist in the prior art. For example EPO 320296 relates to fabric softening additives for detergent compositions which soften natural fibres without causing redeposition problems on synthetics. An intimate mixture of cellulose ethers (0.5-3%, ds up to 3, dp=50-1200) and fabric softener at a ratio of 1:1 to 0.06:1 is disclosed. The fabric softener may be an alkali metal soap.

EPO 213730 relates to detergent compositions for treating fabrics which soften natural fibres without causing redeposition problems. The compositions comprise 0.5-3% nonionic cellulose ethers (HLB 3.1-4.3, ds up to 3, dp 50-1200), a non-soap anionic detergent (2-50%) and a fabric softening agent. The composition is prepared by dry mixing, co- agglomeration or spray drying.

EPO 213729 discloses detergent compositions comprising soap, nonionic surfactants and cellulose ether which exhibits improved low temperature solubility and low level soil redeposition. Anionic surfactants are disclosed as optional surfactants. EPO 256696 discloses a detergent composition for improved soil suspension comprising anionic surfactants (5- 90%), vinyl pyrrolidone polymer and nonionic cellulose ether.

US 4 100 094 discloses a detergent composition containing novel cellulose ethers having a molecular weight of 3000 to 10000 and a ds of 1.8-2.7 as soil release agents. Organic surfactants including anionic surfactants are disclosed (5-60%). The compositions are formulated by dry mixing or spray drying.

US 136 038 discloses detergent compositions comprising 0.1-3% cellulose ether and 5-50% C10-C12 alkyl benzene sulphonate, preferably having a ratio of from 1:5 to 1:50. The granular compositions are prepared by combining all the components except the cellulose ether in an aqueous crutcher slurry and spray drying. The cellulose ether is added dry to the mix.

However, it has been observed that the fabric soil release performance attributable to the incorporation of the nonionic polysaccharide ether in a detergent composition may be significantly reduced due to the dispersal problems of the polysaccharide ether in the wash liquor. As a consequence of the tendency of the polysaccharide ethers to aggregate in the wash, their rate of diffusion is reduced in the vicinity of the fabric and subsequently maximum adsorption on the fabric is not achieved. This problem is further exacerbated under stressed washing conditions, in particular, the utilisation of short washing machine programme cycles or high temperature cycles and the presence of heavily soiled fabrics hinders the performance of the polysaccharide. Furthermore, the development of high density detergent formulations has also served to magnify these problems.

Accordingly, there exists a need to provide a detergent composition comprising a nonionic polysaccharide ether which reduces the tendency of the polysaccharide to aggregate, whilst still providing acceptable soil release performance.

It has now been surprisingly found that this problem may be addressed by the use of a detergent composition comprising a nonionic polysaccharide ether in combination with an anionic surfactant in close physical proximity within said detergent composition.

None of the above identified prior art documents however address the problem of cellulose ether dispersion during the wash. Moreover, the identified prior art does not recognise that these problems may be addressed by the use of polysaccharide ethers in combination with an anionic surfactant in close physical proximity within a detergent composition.

Summary of the Invention

The present invention is a detergent composition comprising a nonionic polysaccharide ether and a non soap anionic surfactant, wherein said polysaccharide ether and said anionic surfactant are in close physical proximity within said detergent composition.

All weights, ratios, amounts and percentages are given as a % weight of the detergent composition unless otherwise stated Detailed Description of the Invention

According to the present invention the detergent composition comprises as essential components a nonionic polysaccharide ether and a non soap anionic surfactant. It has been found that the soil release performance of a nonionic polysaccharide ether may be improved by its use in combination with said anionic surfactant in close physical proximity within said detergent composition. Furthermore the ability of the nonionic polysaccharide ether to disperse in the wash liquor may be improved by the close physical proximity of an anionic surfactant.

Close physical proximity

According to the present invention the anionic surfactant and the nonionic polysaccharide ether are in close physical proximity within said detergent composition. Close physical proximity as used herein encompasses particulates, granulates, flakes, noodles and extrudates containing said anionic surfactant and said nonionic polysaccharide ether. In a preferred embodiment of the present invention said surfactant and said ether are in intimate admixture within said composition such that they are adjacent within said paniculate, granulate, flake, noodle and extrudate. In another embodiment of the present invention the polysaccharide ether and said anionic surfactant are present in the same paniculate, granulate, flake, noodle or extrudate, but are not adjacent and are separated by one or more of the optional additional components of the paniculate, flake, granulate, noodle or extrudate, for example by means of at least one layer.

Nonionic Polysaccharide ethers

According to the present invention an essential component of the intimate mix is a nonionic polysaccharide ether. Chemically, the polysaccharides are composed of pentoses or hexoses. Suitable polysaccharide ethers for use herein are selected from cellulose ethers, starch ethers, dextran ethers and mixtures thereof. Preferably said nonionic polysaccharide ether is a cellulose ether. Cellulose ethers are generally obtained from vegetable tissues and fibres, including cotton and wood pulp. The hydroxy group of the anhydro glucose unit of cellulose can be reacted with various reagents thereby replacing the hydrogen of the hydroxyl group with other chemical groups. Various alkylating and hydroxyalkylating agents can be reacted with cellulose ethers to produce either alkyl-, hydroxyalkyl- or alkylhydroxyalkyl-cellulose ethers or mixtures thereof. The most preferred for use in the present invention are C1-C4 alkyl cellulose ether or a C1-C4 hydroxyalkyl cellulose ether or a C1-C4 alkylhydroxy alkyl cellulose ether or mixtures thereof. Preferably the polysaccharides of the present invention have a degree of substitution of from 0.5 to 2.8, preferably from 1 to 2.5, most preferably from 1.5 to 2 inclusive.

Suitable nonionic cellulose ethers include methyl- and ethyl-cellulose ether, hydroxypropyl-, hydroxybutyl- and hydroxyethyl- methylcellulose ether, hydroxypropyl and hydroxyethyl- cellulose ether, hydroxybutyl methylcellulose ether, ethylhydroxy ethylcellulose ether, hydroxy ethylcellulose ether, methylhydroxy ethyl carboxy methyl cellulose and carboxymethyl hydroxyethyl cellulose. Most preferably said polysaccharide is a methylcellulose ether commercially available such as Methocel (Dow Chemicals), methylhydroxy ethylcellulose ether and mixtures thereof.

According to the present invention said polysaccharide ether preferably has a molecular weight from 10000 to 200000, most preferably from 30000 to 150000. The weight average molecular weight is obtained by standard analytical methods as described in Polymer handbooks. A preferred method is light scattering from polymer solutions as originally defined by Debye.

The compositions of the present invention comprise from 0.01 % to 10%, preferably from 0.01% to 3%, most preferably from 0.1% to 2% of said nonionic polysaccharide ethers.

Non soap Anionic surfactants

According to the present invention the other essential component of the intimate mix is a non soap anionic surfactant. Anionic surfactants useful herein include the conventional primary, branched-chain and random C10-C20 alkyl sulphates ("AS"), the C10-C18 secondary (2,3) alkyl sulphates of the formula CH3(CH2)χ(CHOSθ3^_M⁺) CH3 and CH3 (CH2)_y(CHOSθ3^"M⁺) CH2CH3 where x and (y + 1) are integers of at least about 7, preferably at least about 9, and M is a water-solubilizing cation, especially sodium, unsaturated sulphates such as oleyl sulphate, the C10-C18 alkyl alkoxy sulphates ("AE_XS"; especially EO 1-7 ethoxy sulphates), C-jo-C-jβ alkyl alkoxy carboxylates (especially the EO 1-5 ethoxycarboxylates), sulphated C10-C18 alkyl polyglycosides, and C12-C18 alpha-sulphonated fatty acid esters.

According to the present invention suitable alkyl or hydroxyalkyl alkoxylated sulphates for use herein are of the formula RO(A)_mSθ3M, wherein R is an unsubstituted C11-C24 alkyl or hydroxyalkyl component, preferably a C12-C20 - alkyl or hydroxyalkyl, more preferably a C12-C18 alkyl or hydroxyalkyl component, A is an ethoxy or propoxy group, m is from 1 to 15, more preferably from 1 to 10, and M is H or a cation which may be selected from metal cations such as sodium, potassium, lithium, calcium, magnesium, ammonium or subsituted ammonium. Specific examples of substituted ammonium cations include methyl-, dimethyl-, trimethyl- ammonium and quaternary ammonium cations such as tetramethyl- ammonium, dimethyl piperidium and cations derived from alkanolamines, e.g. monoethanolamine, diethanolamine and triethanolamine and mixtures thereof. Exemplary surfactants are C12-C18 alkyl polyethoxylate (2.25) sulphate, C12-C18 alkyl polyethoxylate (3) sulphate, C14-C15 alkylpolyethoxylate (0.6) and C12-C18 alkyl polyethoxylate (4) sulphate wherein M is selected from sodium or potassium. C12-C14 alkyl sulphate which has been ethoxylated with an average of from 0.5 to 4 moles of ethylene oxide per molecule is especially preferred.

Other suitable anionic surfactants for use herein include salts (e.g. alkali metal and ammonium salts) of C-J 1-C24, preferably C12-C20 linear alkylaryl sulphonates, particularly linear alkyl benzene sulphonates, primary or secondary alkane sulphonates, alkene sulphonates such as α-olefin sulphonates, ether sulphonates, sulphonated polycarboxylic acids, oxyalkane sulphonates (fatty acid isethionates), alkyl sarcosinates, acylamino alkane sulphonates (taurides), alkyl glycerol sulphonates, fatty acyl glycerol sulphonates, fatty oleyl glycerol sulphonates, and any mixtures thereof.

According to the present invention the compositions comprise from 1 % to 80%, preferably from 2% to 50%, most preferably from 5% to 40% of said non soap anionic surfactant.

The intimate mix preferably comprises said polysaccharide ether and said non soap anionic surfactant at a ratio of from 1:1000 to 1:1, preferably from 1:500 to 1:5, more preferably from 1:100 to 1:10.

According to the present invention the anionic surfactant and nonionic polysaccharide paniculate may comprise a number of additional components commonly employed in the formulation composite particles. Suitable components include absorbant builders such as zeolites, chelants, structurant materials such as acrylic/maleic acid based copolymers and inorganic fillers such as sulphates and carbonates. A full description of such components is given in the following detergent composition description herein.

Detergent composition

According to the present invention the detergent composition may comprise a number of optional ingredients commonly employed for detergent applications such as surfactants, builders, chelants, polymers, antiredeposition agents and the like.

Optional surfactants

If desired, the conventional nonionic and amphoteric surfactants such as the C12-C18 alkyl ethoxylates ("AE") including the so-called narrow peaked alkyl ethoxylates and CQ-C-\2 alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), C12-C18 betaines and sulphobetaines ("sultaines"), C*|n-C-i8 amine oxides, and the like, can also be included in the overall compositions. The CiQ-C-jβ N-alkyl polyhydroxy fatty acid amides can also be used. Typical examples include the C12- 18 N-methylglucamides. See WO 9,206,154. Other sugar-derived surfactants include the N-alkoxy polyhydroxy fatty acid amides, such as Cio-C-jβ ^N_(^3_ methoxypropyl) glucamide. The N-propyl through N-hexyl C12-C18 glucamides can be used for low sudsing. C10-C2O ∞^nventional soaps may also be used. If high sudsing is desired, the branched-chain C10- 16 soaps may be used. In addtion to being in close proximity to the nonionic polysaccharide ether, anionic surfactants may be present in the detergent composition as a component of the surfactant system.

Cationic surfactant

Cationic detersive surfactants suitable for use herein are those having one long chain hydrocarbyl group. Examples of such cationic surfactants include the ammonium surfactants such as alkyldimethylammonium halogenides and surfactants having the formula:

[R2(OR³)y][R⁴(OR3)_y]₂R⁵N⁺X-

wherein R² is an alkyl or alkyl benzyl group having from about 8 to about 18 carbon atoms in the alkyl chain, each R³ is selected from the group consisting of CH₂CH₂-, -CH₂CH(CH₃)-, -CH₂CH(CH2θH)-, -CH₂CH2CH₂-, and mixtures thereof; each R⁴ is selcted from the group consisting of C1-C4 alkyl, C1-C4 hydroxyalkyl, benzyl ring structures formed by joining the two R⁴ groups, -CH2CHOH-CHOHCOR⁶CHOHCH₂OH wherein R⁶ is any hexose or hexose polymer having a molecular weight less than about 1000 and hydrogen when y is not 0; R$ is the same as R⁴ or is an alkyl chain wherein the total number of carbon atoms of R2 plus R5 is not more than about 18; each y is from about 0 to about 10 and the sum of the y values is from 0 to about 15; and X is any compatible anion.

Preferred cationic surfactants are the water soluble quaternary amonium compounds useful in the present composition have the formula:

Rl R2^R3R4^N+x"

wherein R-* is a CQ-C-\Q alkyl, each of R2_ R3 and R4 is independently C*|- C4 alkyl, C1-C4 hydroxy alkyl, benzyl and (C2H4O.XH where x has a value of from 1 to 5 and X is an anion. Not more than one of the R2, R3 or R4 should be benzyl.

The preferred alkyl chain length for R-* is from C12-C15, particularly where the alkyl group is a mixture of chain lengths derived from coconut or palm kernel fat or is derived from synthetically by olefin build up or OXO alcohols synthesis. Preferred groups for the R2R3 and R4 are methyl and hydroxyethyl groups and the anion X may be selected from halide, methosulphate, acetate and phosphate ions.

Examples of suitable quaternary ammonium compounds for use herein are: coconut trimethyl ammonium chloride or bromide; coconut methyl dihydroxyethyl ammonium chloride or bromide; decyl trimethyl ammonium chloride; decyl dimethyl hydroxyethyl ammonium chloride or bromide; C12- C*i5 dimethyl hydroxyethyl ammonium chloride or bromide; coconut dimethyl hydroxyethyl ammonium chloride or bromide; myristyl trimethyl ammonium methyl sulphate; lauryl dimethyl benzyl ammonium chloride or bromide; lauryl dimethyl (ethoxy)4 ammonium chloride or bromide and choline esters.

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 paniculate 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 1% builder. Liquid formulations typically comprise from 5% to 50%, more typically about 5% to 30%, by weight, of detergent builder. Granular formulations typically comprise from 10% to 80%, more typically from 15% to 50% by weight, of the detergent builder. Lower or higher levels of builder, however, are not meant to be excluded. Inorganic or P-containing detergent builders include, but are not limited to, the alkali metal, ammonium and alkanolammonium salts of polyphosphates (exemplified by the tripolyphosphates, pyrophosphates, orthophosphates and glassy polymeric meta-phosphates), phosphonates, phytic acid, silicates, carbonates (including bicarbonates and sesquicarbonates), sulphates, and aluminosilicates (see, for example, U.S. Patents 3,159,581 ; 3,213,030; 3,422,021 ; 3,400,148 and 3,422,137).

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.

Examples of silicate builders are the alkali metal silicates, particularly those having a Siθ2:Na2θ 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- Na2Si2θ5 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 NaMSi_xθ2χ+ -y^O 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-Na2Si2θs (NaSKS-6 form) is most preferred for use herein. 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 useful in the present invention. Aluminosilicate builders are of great importance in most currently marketed heavy duty granular detergent compositions, and can also be a significant builder ingredient in liquid detergent formulations. Aluminosilicate builders include those having the empirical formula:

M₂[(Si0₂)w(zAlθ2)y] xH2θ wherein w, 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), Zeolite MAP and Zeolite X. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material has the formula:

Na₁₂[(Alθ2)i2(Si0₂)i2] H2θ wherein x is from about 20 to about 30, especially about 27. This material is known as Zeolite A. Dehydrated zeolites (x = 0 - 10) may also be used herein. 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. 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 ^■TMSTDS" 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 hydroxypolycarboxylates, 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-thcarboxylic 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 liquid detergent formulations due to their availability from renewable resources and their biodegradability. Citrates can also be used in granular compositions, especially 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.

Chelatino 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 ethylenediaminetetracetates, N-hydroxyethylethylenediaminetriacetates, nitrilotriacetates, ethylenediamine tetraproprionates, triethylenetetraamine- hexacetates, diethylenetriaminepentaaceta.es, 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) as DEQUEST. Preferred, these amino phosphonates to 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 ethylenediamine disuccinate ("EDDS"), especially the [S,S] isomer 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 0.1% to 10% more preferably, from 0.1% to 3.0% by weight of such compositions.

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, or (iii) poly (vinyl ester) segments, preferably polyvinyl acetate), having a degree of polymerization of at least 2.

Typically, the polyoxyethylene segments of (a)(i) will have a degree of polymerization of from 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 copolymeric blocks of ethylene terephthalate or propylene terephthalate with polyethylene oxide or polypropylene oxide terephthalate, and the like.

Soil release agents characterized by poly(vinyl ester) hydrophobe segments include graft copolymers of poly(vinyl ester), e.g., C-j-Cβ 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 (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 contains 10-15% by weight of ethylene terephthalate units together with 90-80% by weight of polyoxyethylene terephthalate units, derived from a polyoxyethylene glycol of average molecular weight 300-5,000. 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 sulfoaroiyl, 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%. Still another preferred soil release agent is an oligomer with repeat units of terephthaloyl units, sulfoisoterephthaloyl units, oxyethyleneoxy and oxy-1 ,2-propylene units. The repeat units form the backbone of the oligomer and are preferably terminated with modified isethionate end-caps. A particularly preferred soil release agent of this type comprises about one sulfoisophthaloyl unit, 5 terephthaloyl units, oxyethyleneoxy and oxy-1 ,2- propyleneoxy units in a ratio of from about 1.7 to about 1.8, and two end-cap units of sodium 2-(2-hydroxyethoxy)-ethanesulfonate. Said soil release agent also comprises from about 0.5% to about 20%, by weight of the oligomer, of a crystalline-reducing stabilizer, preferably selected from the group consisting of xylene sulfonate, cumene sulfonate, toluene sulfonate, and mixtures thereof.

As a practical matter, and not by way of limitation, the compositions and processes herein can be adjusted to provide on the order of at least one part per ten million of the active bleach catalyst species in the aqueous washing liquor, and will preferably provide from about 0.1 ppm to about 700 ppm, more preferably from about 1 ppm to about 500 ppm, of the catalyst species in the laundry liquor.

Bleaching Compounds - Bleaching Agents and Bleach Activators

The detergent compositions herein may optionally contain bleaching agents or bleaching compositions containing a bleaching agent and one or more bleach activators. When present, bleaching agents will typically be at levels of from 1% to 40%, more typically from 5% to 30%, of the detergent composition, especially for fabric laundering. If present, the amount of bleach activators will typically be from 0.1% to 60%, more typically from 0.5% to 40% of the bleaching composition comprising the bleaching agent- plus-bleach activator.

The bleaching agents used herein can be 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. Peroxygen bleaching agents can also be used. Suitable peroxygen bleaching compounds include sodium carbonate peroxyhydrate 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.

A preferred percarbonate bleach comprises dry particles having an average particle size in the range from about 500 micrometers to about 1 ,000 micrometers, not more than about 10% by weight of said particles being smaller than about 200 miαometers and not more than about 10% by weight of said particles being larger than about 1,250 micrometers. Optionally, the percarbonate can be coated with silicate, borate or water- soluble surfactants. Preferred coatings are based on carbonate/sulphate mixtures. Percarbonate is available from various commercial sources such as FMC, Solvay and Tokai Denka.

Another category of bleaching agent that can be used without restriction encompasses percarboxylic acid bleaching agents and salts thereof. Suitable examples of this class of agents include magnesium monoperoxyphthalate hexahydrate, the magnesium salt of metachloro perbenzoic acid, 4-nonylamino-4-oxoperoxybutyric acid and diperoxydodecanedioic acid. Such bleaching agents are disclosed in U.S. Patent 4,483,781 , Hartman, issued November 20, 1984, U.S. Patent Application 740,446, Burns et al, filed June 3, 1985, European Patent Application 0,133,354, Banks et al, published February 20, 1985, and U.S. Patent 4,412,934, Chung et al, issued November 1 , 1983. Highly preferred bleaching agents also include 6-nonylamino-6-oxoperoxycaproic acid as described in U.S. Patent 4,634,551 , issued January 6, 1987 to Burns et al.

Mixtures of bleaching agents can also be used. Peroxygen bleaching agents, the perborates, e.g., sodium perborate (e.g., mono- or tetra-hydrate) , the percarbonates, etc., are preferably combined with bleach activators, which lead to the in situ production in aqueous solution (i.e., during the washing process) of the peroxy acid corresponding to the bleach activator. Various nonlimiting examples of activators are disclosed in U.S. Patent 4,915,854, issued April 10, 1990 to Mao et al, and U.S. Patent 4,412,934. The nonanoyloxybenzene sulfonate (NOBS) and tetraacetyl ethylene diamine (TAED) activators are typical, and mixtures thereof can also be used. See also U.S. 4,634,551 for other typical bleaches and activators useful herein. It has also been observed that the incorporation of nonanoyloxybenzene sulphonate in a nonionic polysaccharide ether containing composition (as illustrated in Example 4, C-F) provides an additional colour care performance benefit. It appears that the colour fidelity of certain coloured fabrics when subjected to repetitive washing with a composition comprising NOBS in combination with polysaccharide ethers improves the colour fidelity of the fabrics versus a composition without polysaccharide ether.

Highly preferred amido-derived bleach activators are those of the formulae:

R1 N(R5)C(0)R2C(0)L or R1 C(0)N(R5)R2C(0)L

wherein R¹ is an alkyl group containing from about 6 to about 12 carbon atoms, R is an alkylene containing from 1 to about 6 carbon atoms, R⁵ is H or alkyl, aryl, or alkaryl containing from about 1 to about 10 carbon atoms, and L is any suitable leaving group. A leaving group is any group that is displaced from the bleach activator as a consequence of the nucleophilic attack on the bleach activator by the perhydroxyl anion. A preferred leaving group is phenol sulfonate.

Preferred examples of bleach activators of the above formulae include (6-octanamido-caproyl)oxybenzenesulfonate, (6- nonanamidocaproyl)- oxybenzenesulfonate, (6-decanamido- caproyl)oxybenzenesulfonate, and mixtures thereof as described in U.S. Patent 4,634,551, incorporated herein by reference.

Another class of bleach activators comprises the benzoxazin-type activators disclosed by Hodge et al in U.S. Patent 4,966,723, issued October 30, 1990, incorporated herein by reference. A highly preferred activator of the benzoxazin-type is:

Still another class of preferred bleach activators includes the acyl lactam activators, especially acyl caprolactams and acyl valerolactams of the formulae:

wherein R⁶ is H or an alkyl, aryl, alkoxyaryl, or alkaryl group containing from 1 to about 12 carbon atoms. Highly preferred lactam activators include benzoyl caprolactam, octanoyl caprolactam, 3,5,5-trimethylhexanoyl caprolactam, nonanoyl caprolactam, decanoyl caprolactam, undecenoyl caprolactam, benzoyl valerolactam, octanoyl valerolactam, decanoyl valerolactam, undecenoyl valerolactam, nonanoyl valerolactam, 3,5,5- trimethylhexanoyl valerolactam and mixtures thereof. See also U.S. Patent 4,545,784, issued to Sanderson, October 8, 1985, incorporated herein by reference, which discloses acyl caprolactams, adsorbed into sodium perborate. Other preferred activators are cationic bleach activators.

Bleaching agents other than oxygen bleaching agents are also known in the art and can be utilized herein. One type of non-oxygen bleaching agent of particular interest includes 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. If used, detergent compositions will typically contain from 0.025% to 1.25%, by weight, of such bleaches, especially sulfonate zinc phthalocyanine.

If desired, the bleaching compounds can be catalyzed by means of a manganese compound. Such compounds are well known in the art and include, for example, the manganese-based catalysts disclosed in U.S. Pat. 5,246,621 , U.S. Pat. 5,244,594; U.S. Pat. 5,194,416; U.S. Pat. 5,114,606; and European Pat. App. Pub. Nos. 549,271 A1, 549.272A1, 544.440A2, and 544.490A1 ; Preferred examples of these catalysts include Mn'^V2(u- 0)3(1 ,4,7-trimethyM ,4,7-triazacyclononane)2(PF6)2, Mn'*-2(u-0)ι(u-

0Ac)2(1 ,4,7-trimethyl-1 ,4,7-triazacyclononane)2-(Clθ4)2, Mn^,V4(u-

0)6(1 ,4,7-triazacyclononane)4(CI04)4, Mn Mn^|V₄(_u-0)ι(u-OAc)2-(1 ,4,7- thmethyl-1 ,4,7-triazacyclononane)2(CI04)3, Mn^,v(1 ,4,7-trimethyl-1 ,4,7- triazacyclononane)- (0CH3)3(PF5), and mixtures thereof. Other metal- based bleach catalysts include those disclosed in U.S. Pat. 4,430,243 and U.S. Pat. 5,114,611. The use of manganese with various complex ligands to enhance bleaching is also reported in the following United States Patents: 4,728,455; 5,284,944; 5,246,612; 5,256,779; 5,280,117; 5,274,147; 5,153,161; 5,227,084;

Polymeric Dispersing Agents

Polymeric dispersing agents can advantageously be utilized at levels from 0.1% to 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 or 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 90,000, most preferably from about 7,000 to 80,000. 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 70:30 to 30:70. 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, as well as in EP 193,360, published September 3, 1986, which also describes such polymers comprising hydroxypropylacrylate. Still other useful dispersing agents include the maleic/acrylic/vinyl alcohol or acetate terpolymers. Such materials are also disclosed in EP 193,360, including, for example, the 45/45/10 terpolymer of acrylic maleic vinyl alcohol.

Another polymeric material which can be included is polyethylene glycol (PEG). PEG can exhibit dispersing agent performance 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. Polyamino acid dispersing agents such as polyaspartate and polyglutamatemay also be used, especially in conjunction with zeolite builders. Dispersing agents such as polyaspartate preferably have a molecular weight (avg.) of about 10,000.

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 antire- deposition properties. Granular detergent compositions which contain these compounds typically contain from about 0.01% to about 10.0% by weight of the water-soluble ethoxylates amines; liquid detergent compositions typically contain about 0.01% to about 5%.

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 antiredeposition agent includes the carboxy methyl cellulose (CMC) materials. These materials are well known in the art.

Dve Transfer Inhibiting Agents

The compositions of the present invention may also include one or more materials effective for inhibiting the transfer of dyes from one fabric to another during the cleaning process. Generally, such dye transfer inhibiting agents include polyvinyl pyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, manganese phthalocyanine, peroxidases, and mixtures thereof. If used, these agents typically comprise from 0.01% to 10% by weight of the composition, preferably from 0.01% to 5%, and more preferably from 0.05% to 2%.

More specifically, the polyamine N-oxide polymers preferred for use herein contain units having the following structural formula: R-A_χ-P; wherein P is a polymerizable unit to which an N-0 group can be attached or the N-0 group can form part of the polymerizable unit or the N-0 group can be attached to both units; A is one of the following structures: -NC(O)-, -C(0)0-, -S-, -0-, -N=; x is 0 or 1 ; and R is aliphatic, ethoxylated aliphatics, aromatics, heterocyclic or alicyclic groups or any combination thereof to which the nitrogen of the N-0 group can be attached or the N-0 group is part of these groups. Preferred polyamine N-oxides are those wherein R is a heterocyclic group such as pyridine, pyrrole, imidazole, pyrrolidine, piperidine and derivatives thereof.

The N-0 group can be represented by the following general structures:

wherein R*| , R2, R3 are aliphatic, aromatic, heterocyclic or alicyclic groups or combinations thereof; x, y and z are 0 or 1 ; and the nitrogen of the N-0 group can be attached or form part of any of the aforementioned groups. The amine oxide unit of the polyamine N-oxides has a pKa <10, preferably pKa <7, more preferred pKa <6.

Any polymer backbone can be used as long as the amine oxide polymer formed is water-soluble and has dye transfer inhibiting properties. Examples of suitable polymeric backbones are polyvinyls, polyalkylenes, polyesters, polyethers, polyamide, polyimides, polyacrylates and mixtures thereof. These polymers include random or block copolymers where one monomer type is an amine N-oxide and the other monomer type is an N- oxide. The amine N-oxide polymers typically have a ratio of amine to the amine N-oxide of 10:1 to 1:1,000,000. However, the number of amine oxide groups present in the polyamine oxide polymer can be varied by appropriate copolymerization or by an appropriate degree of N-oxidation. The polyamine oxides can be obtained in almost any degree of polymerization. Typically, the average molecular weight is within the range of 500 to 1 ,000,000; more preferred 1,000 to 500,000; most preferred 5,000 to 100,000. This preferred class of materials can be referred to as "PVNO".

The most preferred polyamine N-oxide useful in the detergent compositions herein is poly(4-vinylρyridine-N-oxide) which as an average molecular weight of about 50,000 and an amine to amine N-oxide ratio of about 1 :4.

Copolymers of N-vinylpyrrolidone and N-vinylimidazole polymers (referred to as a class as "PVPVI") are also preferred for use herein. Preferably the PVPVI has an average molecular weight range from 5,000 to 1,000,000, more preferably from 5,000 to 200,000, and most preferably from 10,000 to 20,000. (The average molecular weight range is determined by light scattering as described in Barth, et al., Chemical Analysis. Vol 113. "Modern Methods of Polymer Characterization", the disclosures of which are incorporated herein by reference.) The PVPVI copolymers typically have a molar ratio of N-vinylimidazole to N-vinylpyrrolidone from 1:1 to 0.2:1, more preferably from 0.8:1 to 0.3:1, most preferably from 0.6:1 to 0.4:1. These copolymers can be either linear or branched. It has also been observed that additional dye transfer inhibition benefits are provided by compositions comprising nonionic polysaccharide ethers and dye transfer inhibitors such as PVNO and PVPVI such as illustrated in Example 1 , formulation B, C and D. It is believed that a synergic effect due to the combination of polysaccharides and dye transfer inhibitors provides the unexpected whiteness maintainance performance benefits to white fabrics which have been subjected to repetitive washing.

The present invention compositions also may employ a polyvinylpyrrolidone ("PVP") having an average molecular weight of from about 5,000 to about 400,000, preferably from about 5,000 to about 200,000, and more preferably from about 5,000 to about 50,000. PVP's are known to persons skilled in the detergent field; see, for example, EP-A- 262,897 and EP-A-256,696, incorporated herein by reference. Compositions containing PVP can also contain polyethylene glycol ("PEG") having an average molecular weight from about 500 to about 100,000, preferably from about 1,000 to about 10,000. Preferably, the ratio of PEG to PVP on a ppm basis delivered in wash solutions is from about 2:1 to about 50:1 , and more preferably from about 3:1 to about 10:1.

The detergent compositions herein may also optionally contain from 0.005% to 5% by weight of certain types of hydrophilic optical brighteners which also provide a dye transfer inhibition action. If used, the compositions herein will preferably comprise from 0.01% to 1% by weight of such optical brighteners.

The hydrophilic optical brighteners useful in the present invention are those having the structural formula:

wherein R-* is selected from anilino, N-2-bis-hydroxyethyl and NH-2- hydroxyethyl; R2 is selected from N-2-bis-hydroxyethyl, N-2-hydroxyethyl-N- methylamino, morphilino, chloro and amino; and M is a salt-forming cation such as sodium or potassium.

When in the above formula, R-* is anilino, R2 is N-2-bis-hydroxyethyl and M is a cation such as sodium, the brightener is 4,4',-bis[(4-anilino-6-(N- 2-bis-hydroxyethyl)-s-triazine-2-yl)amino]-2,2'-stilbenedisulfonic acid and disodium salt. This particular brightener species is commercially marketed under the tradename Tinopal-UNPA-GX by Ciba-Geigy Corporation. Tinopal-UNPA-GX is the preferred hydrophilic optical brightener useful in the detergent compositions herein.

When in the above formula, R** is anilino, R2 is N-2-hydroxyethyl-N- 2-methylamino and M is a cation such as sodium, the brightener is 4,4'- bis[(4-anilino-6-(N-2-hydroxyethyl-N-methylamino)-s-triazinβ-2-yl)amino]2,2'- stilbenedisulfonic acid disodium salt. This particular brightener species is commercially marketed under the tradename Tinopal 5BM-GX by Ciba- Geigy Corporation.

When in the above formula, R*j is anilino, R2 is morphilino and M is a cation such as sodium, the brightener is 4,4^,-bis[(4-anilino-6-morphilino-s- triazine-2-yl)amino]2,2'-stilbenedisulfonic acid, sodium salt. This particular brightener species is commercially marketed under the tradename Tinopal AMS-GX by Ciba Geigy Corporation.

The specific optical brightener species selected for use in the present invention provide especially effective dye transfer inhibition performance benefits when used in combination with the selected polymeric dye transfer inhibiting agents hereinbefore described. The combination of such selected polymeric materials (e.g., PVNO and/or PVPVI) with such selected optical brighteners (e.g., Tinopal UNPA-GX, Tinopal 5BM-GX and/or Tinopal AMS- GX) provides significantly better dye transfer inhibition in aqueous wash solutions than does either of these two detergent composition components when used alone. Without being bound by theory, it is believed that such brighteners work this way because they have high affinity for fabrics in the wash solution and therefore deposit relatively quick on these fabrics. The extent to which brighteners deposit on fabrics in the wash solution can be defined by a parameter called the "exhaustion coefficient". The exhaustion coefficient is in general as the ratio of a) the brightener material deposited on fabric to b) the initial brightener concentration in the wash liquor. Brighteners with relatively high exhaustion coefficients are the most suitable for inhibiting dye transfer in the context of the present invention.

Of course, it will be appreciated that other, conventional optical brightener types of compounds can optionally be used in the present compositions to provide conventional fabric "brightness" benefits, rather than a true dye transfer inhibiting effect. Such usage is conventional and well-known to detergent formulations.

According to the present invention the detergent composition may comprise any other ingredients commonly employed in conventional detergent compositions such as soaps, suds suppressors, softeners, brighteners, additional enzymes and enzyme stabilisers.

Form of the compositions

The compositions of the present invention may be used in laundry detergent compositions, fabric treatment compositions and fabric softening compositions in addition to hard surface cleaners. The compositions may be formulated as conventional granules, bars, pastes or powders. The detergent compositions are manufactured in conventional manner, for example in the case of powdered detergent compositions, spray drying, spray mixing or agglomeration processes may be utilised.

Preferably granular detergent compositions according to the present invention have a density of from 400g/l to 1200g/l, preferably from 500g/l to 1000g/l, more preferably from 600g/l to 1000g/l.

The mean particle size of the components in accordance with the invention should preferably be such that no more than 5% of the particles are greater than 1.7mm in diameter and not more than 5% are less than 0.15mm in diameter.

The intimate mix of the polysaccharide ether and the anionic surfactant of the present invention are present at at least 10ppm in the aqueous wash solution having a pH of from 7 to 11, preferably from 9 to 10.5.

Method of laundering

The present invention also relates to a method of laundering fabrics which comprises contacting said soiled fabric with an aqueous laundry liquor containing conventional detersive ingredients described herein in addition to the intimate mix paniculate of nonionic polysaccharide ether and anionic surfactant of the present invention. In a preferred method polyester and polyester-cotton blends fabrics are used. Processing

According to the present invention the intimate admix of nonionic surfactant and nonionic polysaccharide ether may be prepared by agglomeration and spray drying techniques.

Accordingly, the agglomeration process steps of the present invention comprise:

1. Mixing a surfactant premix of optional chelant and polymer

2. Drying (optional)

3. Transferring to a high speed mixer, preferably by means of a twin screw extruder.

4. Agglomerating surfactant paste with an effective amount of powder comprising nonionic polysaccharide ether.

It will be understood that any convenient order of the process steps listed above can be contemplated. Also it may be possible and even advantageous to carry out two or more of the above operations in a single piece of process equipment. Each of these operations will now be described in more detail.

Making a Paste Premix

The surfactant paste premix may be prepared by any method which is known to the man skilled in the art. Particularly useful methods include sulphation and/or sulphonation or other reactions to make the desired anionic surfactants e.g. in a falling film sulphonating reactors, digestion tanks, esterification reactors, etc.

It is particularly convenient to neutralise the acid precursors of anionic surfactants in a continuous neutralisation loop. In such a piece of equipment the acid precursor is fed into a loop together with a neutralising agent such as aqueous sodium hydroxide. The components are intimately mixed to promote neutralisation and then fed through a heat exchanger to be cooled. A proportion of the neutralised surfactant is removed from the loop, whilst the remainder is fed back to the point of injection of the acid and the alkali, and passes around the loop again.

In the present invention the surfactant paste is then mixed with the optional chelating agent and a solution of a polymer or co-polymer. This may be achieved in any convenient piece of mixing equipment, and may be carried out using any order of addition of the separate or pre-mixed components.

Paste Drying (in-line)

It is preferred that the moisture in the surfactant aqueous paste is as low as possible, while maintaining paste fluidity, since low moisture leads to a higher concentration of the surfactant in the finished particle. Preferably the paste after drying contains between 5 and 40% water, more preferably between 15 and 35% water and most preferably between 15% and 25% water. A highly attractive mode of operation for lowering the moisture of the paste is the installation, in line, of an atmospheric or a vacuum flash drier, or a scraped surface heat exchanger or a wiped film evaporator.

Twin Screw Extruder

The extruder fulfils the functions of pumping and mixing the viscous surfactant paste on a continuous basis. A basic extruder consists of a barrel with a smooth inner cylindrical surface. Mounted within this barrel is the extruder screw. There is an inlet port for the high active paste which, when the screw is rotated, causes the paste to be moved along the length of the barrel.

The detailed design of the extruder allows various functions to be carried out. Firstly additional ports in the barrel may allow other ingredients, including the chemical structuring agents to be added directly into the barrel. Secondly a vacuum pump and a seal around the shaft of the screw allows a vacuum to be drawn which enables the moisture level to be reduced. Thirdly means for heating or cooling may be installed in the wall of the barrel for temperature control. Fourthly, careful design of the extruder screw promotes mixing of the paste both with itself and with other additives. A preferred extruder is the twin screw extruder. This type of extruder has two screws mounted in parallel within the same barrel, which are made to rotate either in the same direction (co-rotation) or in opposite directions (counter-rotation). The co-rotating twin screw extruder is the most preferred piece of equipment for use in this invention.

An extruder is particularly useful in this invention because the paste can be effectively cooled by adding liquid nitrogen or solid carbon dioxide into the barrel (this may be considered surprising, because normally an extruder heats its contents as a result of the mechanical energy input to overcome viscous shear forces) and at the same time pumps the increasingly viscous (colder) paste out of the extruder and into the mixer/agglomerator were granulation takes place.

Suitable twin screw extruders for use in the present invention include those supplied by : APV Baker, (CP series); Werner and Pfleiderer, (Continua Series); Wenger, (TF Series); Leistritz, (ZSE Series); and Buss, (LR Series).

The extruder allows the paste to be conditioned by moisture and temperature reduction. Moisture may be removed under vacuum, preferably between 0 mmHg (gauge) and -55 mmHg (gauge), (0 - 7.3 kPa below atmospheric pressure).

Temperature may be reduced by the addition of solid carbon dioxide or liquid nitrogen directly into the extruder barrel. However, this is not a preferred mode of operation of the present invention.

Fine Dispersion Mixing and Granulation

Any apparatus, plants or units suitable for the processing of surfactants can be used for carrying out the process according to the invention. For mixing/ agglomeration any of a number of mixers/agglomerators can be used. In one preferred embodiment, the process of the invention is continuously carried out. Especially preferred are mixers of the Fukae^ FS-G series manufactured by Fukae Powtech Kogyo Co., Japan; this apparatus is essentially in the form of a bowl-shaped vessel accessible via a top port, provided near its base with a stirrer having a substantially vertical axis, and a cutter positioned on a side wall. The stirrer and cutter may be operated independently of one another and at separately variable speeds. The vessel can be fitted with a cooling jacket or, if necessary, a cryogenic unit.

Other similar mixers found to be suitable for use in the process of the invention include Diosna^R V series ex Dierks & Sόhne, Germany; and the Pharma Matrix^R ex T K Fielder Ltd., England. Other mixers believed to be suitable for use in the process of the invention are the Fuji^R VG-C series ex Fuji Sangyo Co., Japan; and the Roto^R ex Zanchetta & Co srl, Italy.

Other preferred suitable equipment can include Eirich^R, series RV, manufactured by Gustau Eirich Hardheim, Germany; L6dige^R, series FM for batch mixing, series Baud KM for continuous mixing/agglomeration, manufactured by Lόdige Machinenbau GmbH, Paderborn Germany; Drais^R T160 series, manufactured by Drais Werke GmbH, Mannheim Germany; and Winkworth^R RT 25 series, manufactured by Winkworth Machinery Ltd., Berkshire, England.

The Littleford Mixer, Model #FM-130-D-12, with internal chopping blades and the Cuisinart Food Processor, Model #DCX-Plus, with 7.75 inch (19.7 cm) blades are two examples of suitable mixers. Any other mixer with fine dispersion mixing and granulation capability and having a residence time in the order of 0.1 to 10 minutes can be used. The "turbine-type" impeller mixer, having several blades on an axis of rotation, is preferred. The invention can be practiced as a batch or a continuous process.

The paste can be introduced into the mixer at an initial temperature between its softening point (generally in the range of 40-60°C) and its degradation point (depending on the chemical nature of the paste, e.g. alkyl sulphate pastes tend to degrade above 75-85°C). High temperatures reduce viscosity simplifying the pumping of the paste but result in lower active agglomerates. The introduction of the paste into the mixer can be done in many ways, from simply pouring to high pressure pumping through small holes at the end of the pipe, before the entrance to the mixer. While all these ways are viable to manufacture agglomerates with good physical properties, it has been found that in a preferred embodiment of the present invention the extrusion of the paste results in a better distribution in the mixer which improves the yield of particles with the desired size. The use of high pumping pressures prior to the entrance in the mixer results in an increased activity in the final agglomerates. By combining both effects, and introducing the paste through holes (extrusion) small enough to allow the desired flow rate but that keep the pumping pressure to a maximum feasible in the system, highly advantageous results are achieved.

It is also within the scope of the present invention that the resulting detergent granules may be dried, cooled and/or dusted with a suitable surface coating agent.

Spray drying process

According to the present invention the intimate admixture of anionic surfactant and nonionic polysaccharide ether may be prepared using spray drying methods known in the art. Using such a process a mixture of Zeolite A, anionic surfactant, chelant and nonionic polysaccharide ether is mixed in a vessel with stirring. Water is added along with optional viscosity modifying agents. The pH is adjusted to be greater than 10 and additional water is added in order to provide the mixture with the desired flow characteristeics. The mixture is stirred for up to 1 hour. The mixture is then transferred to the top of a spray drying tower unit. The inlet temperature and the resonance time is varied to produce the desired particle size and moisture content. The resulting spray dried powder is collected at the base of the tower.

Examples

Abbreviations used in Examples

In the detergent compositions, the abbreviated component identifications have the following meanings: XYAS Sodium C*jχ - C*jγ alkyl sulphate

25EY A C12-15 predominantly linear primary alcohol condensed with an average of Y moles of ethylene oxide

XYEZ A C*i_x - C*|y predominantly linear primary alcohol condensed with an average of Z moles of ethylene oxide

XYEZS ClX - C-|γ sodium alkyl sulphate condensed with an average of Z moles of ethylene oxide per mole

TFAA C 18-C*| 8 alkyl N-methyl glucamide.

Silicate Amorphous Sodium Silicate (Siθ2:Na2θ ratio = 2.0)

NaSKS-6 Crystalline layered silicate of formula 5-Na2Si2θ5

Carbonate Anhydrous sodium carbonate

MA/AA Copolymer of 30:70 maleic/acrylic acid, average molecular weight about 70,000.

Zeolite A Hydrated Sodium Aluminosilicate of formula Na*i2(A1θ2Siθ2)i2- 27H20 having a primary particle size in the range from 1 to 10 micrometers

Citrate Tri-sodium citrate dihydrate

Percarbonate Anhydrous sodium percarbonate bleach coated with a coating of sodium silicate (Si2θ:Na2θ ratio = 2:1 ) at a weight ratio of percarbonate to sodium silicate of 39:1 CMC Sodium carboxymethyl cellulose

DETPMP Diethylene triamine penta (Methylene phosphonic acid), marketed by Monsanto under the Tradename Dequest 2060

PVNO Poly (4-vinylpyridine)-N-oxide copolymer of vinylimidazole and vinylpyrrolidone having an average molecular weight of 10,000.

Smectite Clay Calcium montmorillonite ex. Colin Stewart Minchem Ltd.

Granular Suds 12% Silicone/silica, 18% stearyl alcohol, 70% Suppressor starch in granular form

LAS Sodium linear C12 alkyl benzene sulphonate

TAS Sodium tallow alkyl sulphate

SAS C12-C14 secondary (2,3) alkyl sulfate in the form of the sodium salt.

SS Secondary soap surfactant of formula 2-butyl octanoic acid

Phosphate Sodium tripolyphosphate

TAED Tetraacetyl ethylene diamine

PVP Polyvinyl pyrrolidone polymer

HMWPEO High molecular weight polyethylene oxide MC Methyl cellulose ether with molecular weight from 110000 to 130000, available from Shin Etsu Chemicals under the tradename Metolose

MHEC Tylose MH300, available from Hoechst

TAE 25 Tallow alcohol ethoxylate (25)

PEO Polyethylene oxide

Sulphate Sodium sulphate

HEDP 1 ,1-hydroxyethane diphosphonic acid

EDDS [s,s] ethylene diamine disuccinate

DHAC : C12 C16 dimethyl hydroxyethyl ammonium chloride

Examples

According to the present invention the detergent composition may be manufactured using any of the methods known in the art such as spray drying, agglomeration, extrusion and pelletisation.

The particle 1 and 2 may be manufactured according to the following process. Similarly particles 11-12 and 25-28 may also be manufactured using a similar method wherein the chelant is omitted.

This example describes the process in batch mode in a lab scale high shear mixer (food processor manufactured by Braun [Trade Name]). Three hundred grams of powders, including nonionic polysaccharide ethers are added first to the mixer. In this particular case a 2:1 ratio of Zeolite A to finely divided light density sodium carbonate is used.

The surfactant is an aqueous paste of C45AS/AE3S (80:20) with a detergent activity of 78%, and a water content of 16%. In this example the paste is pre-mixed in a batch mixer with a 40% solution of the co-polymer of maleic and acrylic acid , sodium salt and a 20% solution of the sodium salt of the ethylene diamine-N,N-disuccinic acid. The weight ratio of paste : polymer : chelating agent was 1 : 0.64 : 0.09. The mixture is then dried to the original paste moisture of 16%. The paste mixture is placed into an oven at 60 °C until thermal equilibrium is reached. The mixer is then started and paste added at a rate of 500g/min until the onset of agglomeration and formation of granules. The end point is shaφ and easily recognized. It is characterized by an increased power draw by the mixer, and a change in the mixer contents from a mixture of finely divided powders and distributed surfactant paste, to agglomerates containing powders and paste having a mean particle size between 400 - 600 micrometers. The activity of the agglomerates formed is 51%.

Particles 13-24 are prepared according to the spray drying process described herein above.

Reference particle and particle 1 and 2

Example 1

The following laundry detergent compositions A, B, C, and D were prepared. Example formulations C and D represent embodiments of the invention.

A B C D

Reference particle 30 30 0 0

Particle 1 0 0 30 0

Particle 2 0 0 0 30

Soil removal testing, using a Hotpoint washing machine, short cycle, 40° C, Newcastle city water with hardness of 12dH, single (75g) dosage was used. The fabrics were first pretreated with each of the formulations A, B and C using the above described conditions. The staining mixtures were evenly spread over the fabric with a brush and left to dry over the bench overnight. The fabrics were then washed with the respective formulation again.

Differences in greasy soil removal performance are recorded in panel score units (psu), positive having a better performance than the reference product. The following grading scale (psu grading) was used:

0 = equal

1 = I think this one is better

2 = I know this one is a little better

3 = This one is a lot better

4 = This one is a whole lot better Grading was done under controlled light conditions by expert graders, The number of replicates used in this test was six.

's' denotes that the observed difference is statistically significant at a 95% confidence level. The significance of the differences between the formulations was obtained using a two way ANOVA calculation. Thus, the differences between the formulations and the differences between replicates were separately calculated using their corresponding variances and the difference was analysed using the F test.

Detergent Detergent Detergent

Panel score units composition A composition B composition

C

Average stains on polycotton

Chicken* 0 +1.0 +1.5

Pizza** 0 +0.9 +1.4

Indian^*** 0 -0.4 +0.4

Tuna^***^* 0 +0.8s +1.4s

Average on four 0 +0.6 +1.2s stains

Chicken^* : chicken casserole sauce Pizza**: pizza topping Indian**^*: Indian tikka massaia sauce. Tuna^***^* : Tuna mayonnaise sauce.

The results indicate that an improvement of stain removal was obtained using formulation C, which represents an embodiment of the present invention in comparison with formulation B wherein the polysaccharide is not in close physical proximity with the anionic surfactant.

Particle examples 3-10 for granular detergent compositions based on a tower process:

Particle 3 4 5 6 7 8

Blown Powder

Phosphate 45 45 - - 43 43

Zeolite A - - 50 50 - -

Sulphate 17 17 12 12 24 24

MA/AA 4 4 8 8 4 4 LAS 11 11 17 17 19 19

TAS 4 4 - - - -

Silicate 13 13 6 6 5.5 5.5

CMC 2 2 2 2 1 1

Brightener 0.4 0.4 .4 .4 0.4 0.4

DETPMP 0.8 0.8 1.3 1.3 0.4 0.4

MC 0.8 - 1.3 - 0.7 -

MHEC - 0.8 - 1.3 - 0.7

Total 100 100 100 100 100 100

Particles 9-12:

Particle 9 10 Particle 11 12

Blown Powder Agglomerates

Zeolite A 64 64 45AS 34 34

LAS 13 13 Zeolite A 38 38

DETPMP 2 2 CMC 1 1

CMC 2 2 MA/AA 6 6

MA/AA 17 17 Carbonate 20 20

MC 2 - MC 1 -

MHEC - 2 MHEC - 1

Total 100 100 100 100

Particles 13-18 produced using a tower process

Particle 13 14 15 16 17 18

Blown Powder

Zeolite A 35 35 30 30 8 8

Sulphate 23 23 14 14 9 9

MA/AA 3.7 3.7 4 4 8 8

LAS 17 17 17 17 28.4 28.4

45AS 10 10 10 10 9 9

Silicate - - 1 1 7 7

Brightener 0.3 0.3 0.3 0.3 0.3 0.3

Carbonate 10 10 22 22 26 26

DETPMP 1 1 0.7 0.7 0.5 0.5

MC 1 - 1 - 0.8 -

MHEC - 1 - 1 - 0.8

Blown Powder particles 19-24 for use in high density granular compositions.

Particle 19 20 21 22 23 24 Blown Powder

Zeolite A 64 64 55 55 65 65

Sulphate - - 18 18 - -

LAS 13 13 11 11 14 14

DHAC - - 5 5 7 7

DETPMP 2 2 1.5 1.5 2 2

CMC 2 2 1.5 1.5 2 2

MM/MA 17 17 7 7 8 8

MC 2 - 1 - 2 -

MHEC - 2 - 1 - 2

Total 100 100 100 100 100 100

Agglomerated particles 25-28.

Particle 25 26 27 28

Agglomerates

LAS 18 18 21 21

TAS 8 8 9 9

Silicate 12 12 17 17

Zeolite A 30 30 34 34

Carbonate 30 30 17 17

MC 2 - 2 -

HMEC - 2 - 2

Total 100 100 100 100

Example 2: Granular detergent compositions.

Composition A B C D E F

Particle 3 53 - - - - -

Particle 4 - 53 - - - -

Particle 5 - - 48 - - -

Particle 6 - - - 48 - -

Particle 7 - - - - 55 -

Particle 8 - - - - - 55

Spray on

AE7 2.5 2.5 2.5 2.5 2.0 2.0

AE3 2.5 2.5 2.5 2.5 2.0 2.0

Silicone antifoam 0.3 0.3 0.3 0.3 0.3 0.3

Perfume 0.3 0.3 0.3 0.3 0.3 0.3

Dry additives

Carbonate 6.0 6.0 13.0 13.0 15.0 15.0

PB4 18.0 18.0 18.0 18.0 10 10

PB1 4.0 4.0 4.0 4.0 0 0

TAED 3.0 3.0 3.0 3.0 1.0 1.0

Example 3: Granular detergent formulations:

sce aneous

Example 4:

Example 5: Compositions E and F represent softening through the wash type compositions

Example 6: Compositions E and F represent softening through the wash formulations

Claims

1. A detergent composition comprising a nonionic polysaccharide ether and a non soap anionic surfactant, wherein said polysaccharide ether and said anionic surfactant are in close physical proximity within said detergent composition.

2. A detergent composition according to claim 1, wherein said nonionic polysaccharide ether and said anionic surfactant are in close physical proximity within a particulate, granulate, flake, noodle or extrudate.

3. A detergent composition according to either of claims 1 or 2, wherein said polysaccharide ether and said anionic surfactant are in intimate admixture within said composition.

4. A detergent composition according to claim 2, wherein said polysaccharide ether and said anionic surfactant are separated from one another .

5. A detergent composition according to any one of the preceding claims, wherein the ratio of said non soap anionic surfactant to said nonionic polysaccharide ether is from 1000:1 to 1:1.

6. A granular detergent composition according to any one of the preceding claims, having a bulk density of from 400g/l to 1200g/l.

7. A granular detergent composition according to any one of the preceding claims, having a bulk density of from 500g/l to 1000g/l.

8. A detergent composition according to any one of the preceding claims, wherein said nonionic polysaccharide ether is a cellulose ether, a starch ether, a dextran ether or mixtures thereof.

9. A detergent composition according to claim 8, wherein said polysaccharide is a cellulose ether selected from nonionic C -C4 alkyl, C1-C4 hydroxyalkyl-, C1-C4 alkylhydroxyalkyl polysaccharide ethers and mixtures thereof.

10. A detergent composition according to any of the preceding claims, wherein said nonionic polysaccharide ether is a methyl cellulose ether, a methylhydroxyethyl cellulose ether or mixtures thereof.

11. A detergent composition according to any of the preceding claims, comprising from 0.01% to 10% of said nonionic polysaccharide ether.

12. A detergent composition according to any one of the preceding claims, wherein said non soap anionic surfactant is selected from alkyl sulphonates, alkyl sulphates, alkyl sarcosinates, alkyl alkoxylated sulphates, alkyl alkoxy carboxylates, sulphated alkyl polyglucosides, alkyl alpha sulphonated fatty acid esters and mixture thereof.

13. A detergent composition according to claim 12, wherein said anionic surfactant is a water soluble salt of a Cβ-Ciβ alkyl sulphate.

14. A detergent composition according to either of claims 12 or 13, comprising from 5% to 40% of said anionic surfactant.

15. A detergent composition according to claim 2, wherein said particulate further comprises detergent adjuncts selected from zeolite builders, chelants, carbonates, polycarboxylates and mixtures thereof.

16. A detergent composition according to any one of the preceding claims, further comprising detergent adjuncts selected from nonionic surfactants, builders, chelants, bleach and mixtures thereof.

17. A method of treating fabrics comprising contacting said fabrics with an aqueous solution comprising at least 10ppm of a detergent composition according to claim 1.