DETERGENT COMPOSITIONS AND COPOLYMERS FOR INHIBITING DYE TRANSFER

Abstract: A detergent composition comprising a copolymer and at least one component selected from surface active agents and fabric softening compounds, the copolymer comprising at least one dye binding monomer and at least one anionic or nonionic monomer, with the proviso that the copolymer is not poly(1-vinylpyrrolidone-co-acrylic acid). Also a method of mitigating dye transfer in a detergent composition in the presence of typically encountered soils is provided. A dye binding copolymer comprising at least one anionic monomer selected from acrylic acid, methacrylic acid, vinyl sulphonic acid, itaconic acid, octanoic acid, hexanoic, hydroxy acetic acid or mixtures thereof or at least one nonionic monomer selected from polyethylene glycols and at least one dye binding monomer selected from vinyl imidazole, methyl vinyl imidazole, vinyl pyridine-N-oxide, vinyl pyrrolidone and mixtures thereof is also disclosed.

Description: DETERGENT COMPOSITIONS AND COPOLYMERS FOR INHIBITING DYE TRANSFER Technical Field The present invention relates to a detergent composition and to a process for inhibiting dye transfer between fabrics during washing. In particular, the invention relates to detergent compositions containing novel dye-transfer inhibition copolymers . Background of the Invention There is a tendency during the laundering of fabrics for coloured fabrics to release dye into the wash solution. This is a most persistent and troublesome problem as this released dye can then be transferred onto other fabrics . A fabric treatment composition comprising an agent which could prevent the transfer of dye would therefore prove useful . EP 62 806 (Unilever) discloses a domestic treatment of a fabric with a cationic dye fixing agent to reduce the amount of dye released from the fabric . Suitable cationic dye fixing agents include the dimethyldiallyl ammonium chloride polymer. Surfactant-containing dye transfer inhibiting compositions are disclosed in EP 0 587 550 (Procter and Gamble) . The dye transfer inhibition agent is a polymer selected from polyamine N-oxide containing polymers. EP 0 327 927 (Procter and Gamble) describes a granular detergent additive comprising water-soluble polymeric compounds based on N-vinylpyrrolidone and/or N-vinylimidazole and/or N-vinyloxazolidine and cationic compounds . Detergent compositions comprising a N-vinylimidazole N- vinylpyrolidone copolymer are disclosed in EP 0 635 566 and EPO 635 565 (Procter and Gamble) . DE 42 24 762A (BASF AG) discloses the use of nitrogen- containing polymers as dye-transfer inhibitors in textile washing, the polymers contain a carbonyl or ester group with the esters being neutral in the co-polymer. EP-A-0-631-008 (Ciba-Geigy AG) relates to an after-washing process for a dyeing operation in which a polyvinyl pyrrolidone homo or co-polymer, and, a water softener are used in the absence of a surfactant. The copolymer can contain comonomers such as those containing carboxyl groups, sulpho groups, phosphorous based groups or other ethylenically unsaturated monomers. Such non-surfactant dyeing after washing processes and compositions used in them are outside the scope of the present invention. EP-0-100-890-A (BASF AG) discloses co-polymers obtained by the radical copolymerisation of monomers of C 3 -C 20 alkyl ester of (meth) acrylic acid N-containing neutrally reacting water- soluble compounds, compounds containing cationic groups and olefinically unsaturated C 3 -C 5 carboxylic acids. The polymers are used in hair treatment compositions . WO 95/27759 discloses ink compositions comprising network forming or cross-linked polymers or resins, where the polymers may include a dye-binding copolymer. EP 687 694 (BASF) discloses a process for the preparation of polymers based on vinyl imidazoles. The process relates to vinyl imidazole co-polymers and homopolymers . WO 91 00302 (GAF) discloses terpolymers which are insoluble in heptane and which are produced from a reaction mixture of a vinyl lactam, a polymersible carboxylic acid and a hydrophobic monomer. WO 95/00611 discloses floor cleaners comprising a copolymer of vinyl pyrrolidone and acrylic acid, dimethylaminoethyl methacrylate, vinyl acetate or methaminopropyl trimethyl ammonium chloride . The copolymers are used as shine boosters . We have found that whilst these polymers of the prior art when used for dye transfer mitigation can be effective in preventing dye transfer under model conditions, in the presence of soil under normal laundering conditions they become ineffective, and can even lead to additional dye transfer. Compositions of the present invention are directed towards overcoming this problem by using co-polymers which even in the presence of soil, retain their dye transfer inhibition properties. Definition of the Invention Accordingly the present invention provides a detergent composition comprising a co-polymer and at least one component selected from surface active agents and fabric softening compounds, the co-polymer comprising at least one dye binding monomer and at least one anionic or nonionic monomer, with the proviso that the co-polymer is not poly (1-vinylpyrrolidone-co- acrylic acid) . The invention further provides a dye binding co-polymer comprising at least one anionic monomer selected from acrylic acid, methacrylic acid, vinyl sulphonic acid, itaconic acid, octanoic acid, hexanoic acid, hydroxy acetic acid or mixtures thereof or at least one nonionic monomer selected from polyethylene glycols, and at least one dye binding monomer selected from vinyl imidazole, methyl vinyl imidazole, vinyl pyridine-N-oxide, vinyl pyrrolidone and mixtures thereof. Of particular interest are dye binding co-polymers of poly (vinylpyrrolidone-co-polyvinylimidazole-co-acrylic acid) or a co-polymer of poly (vinylpyrrolidone-co- polyvinylimidazole-co-methacrylic acid) or a co-polymer of poly (vinylpyrrolidone-co-polymethylvinylimidazole-co-acrylic acid) or a co-polymer of poly (vinylpyrrolidone-co- polymethylvinylimidazole-co-methacrylic acid) . The invention also relates to use of a co-polymer comprising at least one dye binding monomer and at least one anionic or nonionic monomer in a laundry treatment composition to mitigate dye transfer between fabrics. In particular co-polymers of the immediately preceding paragraph comprising 1-10% by weight acrylic acid or methacrylic acid monomers are of use. The invention also relates to the use of co-polymer as according to the present invention to prevent anti-redeposition of soil in washing conditions. The term dye-binding monomer as used herein is used in relation to monomers which have a dye-binding capability when in their polymerised form i.e. the co-polymer comprising the polymerised dye-binding monomers has dye binding characteristics resulting from said monomer. More specifically in the context of the present invention a dye binding monomer is defined as a monomer the homopolymer (mwt of 40,000-100,000) of which binds dye in water at pH 9 at a temperature from 5°C to 60°C, preferably at a temperature of 20°C. However, with this proviso the dye binding homopolymer can bind dye under other conditions. Detailed Description of the Invention The copolymers of the invention contain at least one dye binding monomer and at least one anionic or nonionic monomer. Any dye binding monomer (as defined above) is suitable for use according to the present invention, however it is preferred if the dye binding monomer (s) comprise (s) a nitrogen containing heterocycle. Preferred dye binding monomers include vinyl azlactone, vinyl azlactam, more preferred polymers include vinyl pyrrolidone (VP) , vinyl imidazole (VI), methyl vinyl imidazole (MeVI) vinyl pyridine, vinyl pyridine-N-oxide (VPy-N-O) , vinyl oxazolidone. Especially preferred are vinyl imidazole, methyl vinyl imidazole (meVI) and vinyl pyridine-N-oxide, used alone or in combination with vinyl pyrrolidone and combinations thereof . Any anionic monomer is suitable for use with the invention. However it is preferred if the anionic moiety is based on a carboxy, sulphonate, sulphate, phosphate or phosponate containing material, especially preferred are short chain, poly erisable group carboxy containing material having at least one double bond. Preferred anionic monomers are itaconic acid, aconitic acid, mesaconic acid, citraconic acid, acrylic acid (AA) , methacrylic acid (MA) , octanoic acid, hexanoic acid, vinyl acetic acid, vinyl benzoic acid, vinyl sulphonic acid, vinyl benzene sulphonic acid, vinyl phosphoric acid and hydroxy acrylic oracetic acid. Especially preferred are AA, MA and vinyl sulphonic acid Examples of preferred copolymers are described below. For (ii) it is preferred that R' is H so that the polymer is poly (acrylic acid/VI/VP) . It is possible that VI may have R 1 as CH 3 i.e. be methyl vinyl imidazole which is another preferred co-polymer. This applies for each of (i) - (iii) above . Any nonionic monomer is suitable for use in the present invention. Preferred nonionic monomers are C 1 -C 22 alkyl ketones, Ci. 22 alkyl vinyl ethers, olefins, 1, 2-dimethoxyethylene, styrene derivatives, hydroxyethyl , propyl, butyl (meth) crylates, (meth) acrylic acid Cι-C 22 alkyl esters, (meth) acrolein, (meth) acrylonitrile, (meth) acrylamide, esters or substituted amides of monomers with a carboxy functional group, N- mono/disubstitued (meth) acrylamide (C1-C 22 ) , alkoxy (meth) acrylates, EO x -PO Vj But O z with x, y, z = 0-250, dimethyl/diethyl amino ethyl/propyl/ butyl (methacrylates) . Especially preferred nonionic monomers are polyethylene glycols of molecular weight 100-10,000, preferably 200-8,000. The weight ratio of anionic or nonionic monomer (s) to the dye binding monomer (s) within the co-polymer is preferably from 1:200 to 1:1, more preferably 1:150 to 1:2, most preferably 1:100 to 1:3. It may be desirable to include additional monomers in these dye binding polymer. Examples of these additional monomers include vinyl alcohol, vinyl acetate, vinyl styrene, acrylamide, methyl methacrylate, hydroxyethyl acrylate/methacrylate, IEG acrylate/ ethacrylate, glycidyl acrylate/methacrylate. The addition of these third monomers can cause changes in the properties of these polymers such as solubility, compatibility with liquid products and redeposi ion performance or sequestration ability. However, such further monomers may be included if the properties of the co-polymers are not adversely affected. Additional monomers may also be present for cost minimalisa ion, as a cross-linking moiety or to impart biodegradability. However, non-crosslinked co-polymers are preferred. The co-polymers of the present invention most preferably retain the anionic or nonionic nature of the monomers within the co-polymer. It is preferred if the co-polymer has an average molecular weight range from 2,000 to 200,000 more preferably from 5,000 to 100,000, most If the detergent composition is in liquid form it is preferred if the co-polymer has a molecular weight range from 5,000 to 30,000. If the detergent composition is granular the preferred molecular weight is from 10,000 to 50,000. The detergent compositions may comprise 0.001-5% w/w of the copolymer, preferably 0.1-3%, e.g. 0.1-2%, such as 0.1-1%. In the context of the present invention the most preferred co-polymers are selected from the group consisting of: a) co-polymers of PVP/PVI/AA, PVP/PVI/MA especially where the ratio of PVI/PVP is from 2:1 to 0.2:1, most preferably 1:1 to 0.3:1 b) co-polymers of PVI/AA, PVI/MA and: c) co-polymers of PVPy-N-O/AA, PVPy-N-O/MA. d) co-polymers of PVP/MePVI/AA, PVP/MePVI/MA especially where the weight ratio of PVP:PVI/MePVI is from 90:10 to 10:90, especially 75:25 to 25:75, e.g. 50:50. Co-polymers comprising at least one dye-binding monomer selected from VI, MeVI and VP where the anionic monomer is AA are especially preferred. The ratio of VP/meVI or VI when two dye binding monomers are use d together is preferably in the weight ratio range stated above in a) or d) . It is also advantageous, especially for VP/meVI co-polymers if the anionic monomer, which is preferably AA or MA represents 1- 10% w/w of the copolymer, especially 2-8%, most especially 2.5%- 7% w/w. Excellent results for both the mitigation of dye transfer and anti-redeposition have been obtained with VP/meVI co-polymers containing around 3% MA or AA, particularly when the ratio of the VP/meVI is within the range 90:10 to 10:90, preferably 75:25 to 25:75 e.g. 50:50. In addition to dye transfer inhibition properties the compositions of the invention also exhibit excellent redeposition of soil properties . This is especially advantageous for the co-polymers of VP, with VI or MeVI , and AA or MA. The compositions of the invention comprise a component selected from surface active agents and fabric softening compounds . Typically at least one of the two aforementioned components will be present dependent upon the application. The compositions of the present invention are preferably laundry compositions, especially main wash compositions or rinse-added softening compositions. The main wash compositions may include a fabric softening agent. Surface Active Compounds The detergent compositions of the invention may contain a surface-active compound (surfactant) which may be chosen from soap and non-soap anionic, cationic, nonionic, amphoteric and zwitterionic surface-active compounds and mixtures thereof. Many suitable surface-active compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch. The preferred detergent-active compounds that can be used are soaps and synthetic non-soap anionic and nonionic compounds . It is preferred if the compositions of the invention contain linear alkylbenzene sulphonate, particularly linear alkylbenzene sulphonates having an alkyl chain length of C 8 -C 15 . It is preferred if the level of alkylbenzene sulphonate is from 0 wt% to 30 wt%, more preferably 1 wt% to 25 wt%, most preferably from 2 wt% to 15 wt%. The detergent compositions of the invention may contain other anionic surfactants in amounts additional to the percentages quoted above. Suitable anionic surfactants are well-known to those skilled in the art . Examples include primary and secondary alkyl sulphates, particularly C 8 -Cι 5 primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates. Sodium salts are generally preferred. The compositions of the invention may also contain nonionic surfactant . Nonionic surf ctants that may be used include the primary and secondary alcohol ethoxylates, especially the C 8 _C U aliphatic alcohols ethoxylated with an average of from l to 20 moles of ethylene oxide per mole of alcohol, and more especially the C 10 -C 15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkylpolyglycosides, glycerol monoethers, and polyhydroxyamides (glucamide) . It is preferred if the level of nonionic surfactant is from 0 wt% to 30 wt%, preferably from 1 wt% to 25 wt%, most preferably from 2 wt% to 15 wt%. The choice of surface-active compound (surfactant) , and the amount present, will depend on the intended use of the detergent composition. In fabric washing compositions, different surfactant systems may be chosen, as is well known to the skilled formulator, for handwashing products and for products intended for use in different types of washing machine . The total amount of surfactant present will also depend on the intended end use and may be as high as 60 wt%, for example, in a composition for washing fabrics by hand. In compositions for machine washing of fabrics, an amount of from 5 to 40 wt% is generally appropriate. Typically the compositions will comprise at least 2 wt% surfactant e.g. 2- 60%, preferably 15-40% most preferably 5-35%. Detergent compositions suitable for use in most automatic fabric washing machines generally contain anionic non-soap surfactant, or nonionic surfactant, or combinations of the two in any ratio, optionally together with soap. Fabric Softening Compounds Any conventional fabric softening compound may be used in the compositions of the present invention. The softening compounds may be cationic or nonionic. If the fabric softening compound is to be employed in a main wash detergent composition the compound will typically be nonionic. The fabric softening compound is suitably a substantially water insoluble quaternary ammonium material comprising a single alkyl or alkenyl long chain having an average chain length greater than or equal to C 20 or, more preferably, a compound comprising a polar head group and two alkyl or alkenyl chains having an average chain length greater than or equal to C 14 . Preferably the fabric softening compound has two long chain alkyl or alkenyl chains each having an average chain length greater than or equal to C 16 . Most preferably at least 50% of the long chain alkyl or alkenyl groups have a chain length of C 18 or above It is preferred if the long chain alkyl or alkenyl groups of the fabric softening compound are predominantly linear. The fabric softening compounds used in the compositions of the invention are preferably compounds that provide excellent softening, and characterised by a chain melting beta to L alpha transition temperature greater than 25°C, preferably greater than 35°C, most preferably greater than 45°C. This L beta to L alpha transition can be measured by DSC as defined in " Handbook of Lipid Bilayers, D Marsh, CRC Press, Boca Raton, Florida, 1990 (pages 137 and 337) . Substantially insoluble fabric softening compounds in the context of this invention are defined as fabric softening compounds having a solubility less than 1 xlO "3 wt % in deminerailised water at 20°C. Preferably the fabric softening compounds have a solubility less than l xlO "4 wt %. Most preferably the fabric softening compounds have a solubility less than 1 xlO "8 to l xlO "6 . Preferred fabric softening compounds are quaternary ammonium compounds . It is especially preferred if the fabric softening compound is a water insoluble quaternary ammonium material which comprises a compound having two C 12-ι8 alkyl or alkenyl groups connected to the molecule via at least one ester link. It is preferred if the quaternary ammonium material has two ester links present. An especially preferred ester-linked quaternary ammonium material can be represented by the formula,- R 1 R' N (CH 2 ) n -T-R' (CH 2 ) n -T-R 2 Wherein each R 1 group is independently selected from C 1-4 alkyl, hydroxyalkyl or C 2-4 alkenyl groups; and wherein each R 2 group is independently selected from C 8-28 alkyl or alkenyl groups; 0 0 T is -O-C- or -C-0-; and N is an integer from 0-5. Di (tallowowyloxyethyl) dimethyl ammonium chloride is especially preferred. A second preferred type of quaternary ammonium material can be represented by the formula; CR 2 CH 2 OOCR 2 wherein R 1 , n and R 2 are as defined above. It is advantageous if the quaternary ammonium material is biologically biodegradable. Preferred materials of this class such as 1,2 bis (hardened tallowoyloxy) -3- trimethylammonium propane chloride and their method of preparation are, for example, described in US 4 137 180 (lever Brothers) . Preferably these materials comprise small amounts of the corresponding monoester as described in US 4 137 180 for example 1- hardened tallowoyloxy-2 -hydroxy-3- trimethylammonium propane chloride. Lecithins are also suitable softening compounds . Detergency Builders The detergent compositions of the invention will generally also contain one or more detergency builders if they are for use in the main wash of a laundering process . The total amount of detergency builder in the compositions will typically suitably range from 5 to 80 wt%, preferably from 10 to 60 wt%. Inorganic builders that may be present include sodium carbonate, if desired in combination with a crystallisation seed for calcium carbonate, as disclosed in GB 1 437 950 (Unilever) ; crystalline and amorphous aluminosilicates, for example, zeolites as disclosed in GB 1 473 201 (Henkel) , amorphous aluminosilicates as disclosed in GB 1 473 202 (Henkel) and mixed crystalline/amorphous aluminosilicates as disclosed in GB 1 470 250 (Procter & Gamble) ; and layered silicates as disclosed in EP 164 514B (Hoechst) . Inorganic phosphate builders, for example, sodium orthophosphate, pyrophosphate and tripolyphosphate are also suitable for use with this invention. The detergent compositions of the invention preferably contain an alkali metal, preferably sodium, aluminosilicate builder. Sodium aluminosilicates may generally be incorporated in amounts of from 10 to 70% by weight (anhydrous basis) , preferably from 25 to 50 wt%. The alkali metal aluminosilicate may be either crystalline or amorphous or mixtures thereof, having the general formula: 0.8-1.5 Na 2 0. A1 2 0 3 . 0.8-6 Si0 2 These materials contain some bound water and are required to have a calcium ion exchange capacity of at least 50 mg CaO/g. The preferred sodium aluminosilicates contain 1.5-3.5 Si0 2 units (in the formula above) . Both the amorphous and the crystalline materials can be prepared readily by reaction between sodium silicate and sodium aluminate, as amply described in the literature. Suitable crystalline sodium aluminosilicate ion-exchange detergency builders are described, for example, in GB l 429 143 (Procter & Gamble) . The preferred sodium aluminosilicates of this type are the well-known commercially available zeolites Aand X, and mixtures thereof. The zeolite may be the commercially available zeolite 4Anow widely used in laundry detergent powders. However, according to a preferred embodiment of the invention, the zeolite builder incorporated in the compositions of the invention is maximum aluminium zeolite P (zeolite MAP) as described and claimed in EP 384 070A (Unilever) . Zeolite MAP is defined as an alkali metal aluminosilicate of the zeolite P type having a silicon to aluminium ratio not exceeding 1.33, preferably within the range of from 0.90 to 1.33, and more preferably within the range of from 0.90 to 1.20. Especially preferred is zeolite MAP having a silicon to aluminium ratio not exceeding 1.07,more preferably about 1.00. The calcium binding capacity of zeolite MAP is generally at least 150 mg CaO per g of anhydrous material. Organic builders that may be present include polycarboxylate polymers such as polyacrylates, acrylic/maleic copolymers, and acrylic phosphinates; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates , glycerol mono-, di and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates , dipicolinates , hydroxyethyliminodiacet ates, alkyl- and alkenylmalonates and succinates; and sulphonated fatty acid salts . This list is not intended to be exhaustive . Especially preferred organic builders are citrates, suitably used in amounts of from 5 to 30 wt%, preferably from 10 to 25 wt%; and acrylic polymers, more especially acrylic/maleic copolymers, suitably used in amounts of from 0.5 to 15 wt%, preferably from 1 to 10 wt%. Builders, both inorganic and organic, are preferably present in alkali metal salt, especially sodium salt, form. Bleach Components Detergent compositions according to the invention may also suitably contain a bleach system. Fabric washing compositions may desirably contain peroxy bleach compounds, for example, inorganic persalts or organic peroxyacids, capable of yielding hydrogen peroxide in aqueous solution. Suitable peroxy bleach compounds include organic peroxides such as urea peroxide, and inorganic persalts such as the alkali metal perborates, percarbonates , perphosphates, persilicates and persulphates . Preferred inorganic persalts are sodium perborate monohydrate and tetrahydrate, and sodium percarbonate . Especially preferred is sodium percarbonate having a protective coating against destabilisation by moisture. Sodium percarbonate having a protective coating comprising sodium metaborate and sodium silicate is disclosed in GB 2 123 044B (Kao) . C3757 The peroxy bleach compound is suitably present in an amount of from 0.1 to 35 wt%, preferably from 0.5 to 25 wt%. The peroxy bleach compound may be used in conjunction with a bleach activator (bleach precursor) to improve bleaching action at low wash temperatures. The bleach precursor is suitably present in an amount of from 0.1 to 8 wt%, preferably from 0.5 to 5 wt%. Preferred bleach precursors are peroxycarboxylic acid precursors, more especially peracetic acid precursors and pernoanoic acid precursors. Especially preferred bleach precursors suitable for use in the present invention are N,N,N* ,N. -tetracetyl ethylenediamine (TAED) and sodium noanoyloxybenzene sulphonate (SNOBS) . The novel quaternary ammonium and phosphonium bleach precursors disclosed in US 4 751 015 and US 4 818 426 (Lever Brothers Company) and EP 402971A (Unilever), and the cationic bleach precursors disclosed in EP 284 292A and EP 303 520A (Kao) are also of interest . The bleach system can be either supplemented with or replaced by a peroxyacid. Examples of such peracids can be found in US 4 686 063 and US 5 397 501 (Unilever) . A preferred example is the imido peroxycarboxylic class of peracids described in EP A 325 288, EP A 349 940, DE 382 3172 and EP 325 289. A particularly preferred example is phtalimido peroxy caproic acid (PAP) . Such peracids are suitably present at 0.1 - 12% preferably 0.5 - 10%. A bleach stabiliser (heavy metal sequestrant) may also be present. Suitable bleach stabilisers include ethylenediamine tetraacetate (EDTA) , the polyphosphonates such as Dequest (Trade Mark) and non-phosphate stabilisers such as EDDS (ethylene diamine di-succinic acid) . These Bleach stabilisers are also useful for stain removal especially in products containing low levels of bleaching species or no bleaching species. An especially preferred bleach system comprises a peroxy bleach compound (preferably sodium percarbonate optionally together with a bleach activator) , and a transition metal bleach catalyst as described and claimed in EP 458 397A, EP 458 398A and EP 509 787A (Unilever) . The Enzyme The detergent compositions according to the invention may also contain an enzyme . Suitable enzymes include the proteases, amylases, cellulases, oxidases, peroxidases and lipases usable for incorporation in detergent compositions. Preferred proteolytic enzymes (proteases) are, catalytically active protein materials which degrade or alter protein types of stains when present as in fabric stains in a hydrolysis reaction. They may be of any suitable origin, such as vegetable, animal, bacterial or yeast origin. Proteolytic enzymes or proteases of various qualities and origins and having activity in various pH ranges of from 4-12 are available and can be used in the instant invention. Examples of suitable proteolytic enzymes are the stabilisins which are obtained from particular strains of B. subtilis B. licheniformis , such as the commercially available subtilisins Maxatase (Trade Mark) , as supplied by Gist Brocades N.V. , Delft, Holland, and Alcalase (Trade Mark), as supplied by Novo Industri A/S, Copenhagen, Denmark. Particularly suitable is a protease obtained from a strain of Bacillus having maximum activity throughout the pH range of 8-12, being commercially available, e.g. from Novo Industri A/S under the registered trade-names Esperase (Trade Mark) and Savinase (Trade-Mark) . The preparation of these and analogous enzymes is described in GB 1 243 785. Other commercial proteases are Kazusase (Trade Mark) (obtainable from Showa-Denko of Japan) , Optimase (Trade Mark) (from Miles Kali-Chemie, Hannover, West Germany) , and Superase (Trade Mark) (obtainable from Pfizer of U.S.A.). Detergency enzymes are commonly employed in granular form in amounts of from about 0.1 to about 3.0 wt%. Other ingredients The compositions of the invention may contain alkali metal, preferably sodium carbonate, in order to increase detergency and ease processing. Sodium carbonate may suitably be present in amounts ranging from 1 to 60 wt%, preferably from 2 to 40 wt%. However, compositions containing little or no sodium carbonate are also within the scone of the invention. Powder flow may be improved by the incorporation of a small amount of a powder structurant, for example, a fatty acid (or fatty acid soap) , a sugar, an acrylate or acrylate/maleate copolymer, or sodium silicate. One preferred powder structurant is fatty acid soap, suitably present in an amount of from 1 to 5 wt%. Other materials that may be present in detergent compositions of the invention include sodium silicate; antiredeposition agents such as cellulosic polymers,- inorganic salts such as sodium sulphate; lather control agents or lather boosters as appropriate; proteolytic and lipolytic enzymes,- dyes,- coloured speckles; perfumes,- foam controllers,- fluorescers and decoupling polymers. This list is not intended to be exhaustive. It is advantageous if soil release polymers are present as they enhance the dye transfer inhibition. Particularly preferred are soil release polymers based disclosed in WO 95/32997 A (Rhone Poulenc) ) , EP 219 048 (BASF) , GB 2 208 515 (Colgate) , EP 253 567 (P~G) The detergent composition when diluted in the wash liquor (during a typical wash cycle) will typically give a pH of the wash liquor from 7 to 10.5 for a main wash detergent. The detergent components of the present invention may be incorporated in detergent compositions of all physical types, for example, powders, liquids, gels and solid bars. Detergent compositions of the invention may be prepared by any suitable method. Particulate detergent compositions are suitably prepared by spray-drying a slurry of compatible heat-insensitive ingredients, and then spraying on or postdosing those ingredients unsuitable for processing via the slurry, skilled detergent formulator will have no difficulty in deciding which ingredients should be included in the slurry and which should not . Particulate detergent compositions of the invention preferably have a bulk density of at least 400 g/1, more preferably at least 500 g/1. Especially preferred compositions have bulk densities of at least 650 g/litre, more preferably at least 700 g/litre. Such powders may be prepared either by post-tower densification of spray-dried powder, or by wholly non-tower methods such as dry mixing and granulation; in both cases a hiqh-speed mixer/granulator may advantageously be used. Processes using high-speed mixer/granulators are disclosed, for example, in EP 340 013A, EP 367 339A, EP 390 251A and EP 420 317A (Unilever) . Liquid detergent compositions can be prepared by admixing the essential and optional ingredients thereof in any desired order to provide compositions containing components in the requisite concentrations. Liquid compositions according to the present invention can also be in compact form which means it will contain a lower level of water compared to a conventional liquid detergent. Examples The invention will now be illustrated by the following non- limiting examples. In the examples all percentages are expressed by weight. Further modifications within the scope of the present invention will be obvious to the skilled man. Comparative Examples are designated by letters, while Examples of the invention are designated by numbers. Preparation of Polymers The co-polymers of this invention can be produced by radical polymerisation of the appropriate monomers with or without a crosslinking agent. The polymerisation can be conducted in bulk, in solution (aqueous or organic media) also employing emulsion or suspension polymerisation techniques . Depending on the monomer reactivity ratios and their concentration, the co-polymers will have random or block nature. Example 1 Co-polymerisation of Vinylimidazole & Acrylic Acid (95:5) 1-Vinylimidazole 47g (0.5 mol) Acrylic Acid 1.8g(25 mol) 1,4-Dioxane 250 ml 4 , 4-Azobis (4-cyanovaleric) acid (ACVA) 0.14g The radical polymerisation of 1-Vinylimidazole (0.5 mol) and Acrylic Acid was carried out under nitrogen. After degassing for 30 minutes, the reaction mixture was heated to 70°C and ACVA (0.5 mol) was added. The polymerisation reaction was stirred overnight under a nitrogen atmosphere until the reaction mixture turned cloudy. The bulk of the dioxane was removed and sodium hydroxide solution was added to neutralise the acrylic acid. The remaining dioxane/water was removed, the sample was redissolved in water and freeze dried. NMR Analysis indicate that the co-polymer contains between 4-8% of acrylic acid monomer. GPC Molecular weights against polyethylene glycol standards are: Mn 40970, Mw 137900, D3.366. Example 2 Co-Polymerisation of Vinyli idazole & Acrylic Acid (50:50) 1-Vinylimidazole 18.8g (0.2 mol) Acrylic Acid 14.4g (0.2 mol) 1,4-Dioxane 300 ml 4,4-Azobis (4-cyanovaleric) acid (ACVA) 0.5g The polymerisation was carried out as example 1, but with different monomer ratios. After the polymerisation completed, sodium hydroxide solution was added to the stirred reaction product and the polymer precipitated out . The polymer was redissolved in water and freeze dried or precipitated out using methanol (three times) . NMR spectrum shows that the copolymer contains about 75 % acrylic acid monomer. Example 3 Co-Polymerisation of Vinylimidazole & Acrylic Acid (80 : 20) 1 -Vinylimidazole 25 . 8g ( 0 . 274 mol) Acrylic Acid 3.95g(55 mol) 1,4-Dioxane 250 ml 4,4-Azobis (4-cyanovaleric) acid (ACVA) 0.2g The polymerisation was carried out as example 1, but with different monomer ratios. After the polymerisation completed, sodium hydroxide solution was added to the stirred reaction product and the polymer precipitated out. The polymer was redissolved in water and freeze dried or precipitated out using methanol (three times) . NMR analysis indicate that the co-polymer contains about 18 % of acrylic acid monomer. Dye Transfer Performance Conditions: Shakerbath, 40°C, 30 mins, 100 rpm lOOmls solution made with 26.4°FH water lg/1 total surfactant (combinations of LAS and E07) 0.522g/l NaC0 3 0.87g/l STP lOuM Direct Red 80 dye 13x13cm white mercerised cotton 0.0435q/l polymer After washing, the cloths were rinsed and tumble dried. Their reflectances were measured on a ICS Texicon Spectraflash 500, and the results are given in Table 1 below as delta E values, calculated from the reflectance values. The delta E values shown in the table are differences between washed and unwashed cotton. A high value of delta E corresponds to more dye transfer than a low value. Table 1 In addition to the above it was found that a simple test using soiled fabrics predicts negative interactions between the formulation, dye transfer polymer and soil, but it does not predict positive benefits. It can therefore be used as a gross negative test to distinguish polymers which can give a negative in machine tests (worse than the control in the model test), from those which will either have no effect, or have benefits in the machine tests (equal to or better than the control) at the higher anionic ratios. White cotton monitors were washed together with a piece of dyed test cloth and a piece of soiled test cloth for 30 mins at 40°C in a solution containing lg/1 active (80:20 LAS/NI) , STP and NaC03 made with Prenton water (26.4°FH) . Polymer was added at 0.0218g/l. The delta E values were calculated from the reflectance values of the white monitors and the results compared to the control (no polymer present) . Table 2 The results for PVP, PVI and PVP/PVI are significantly worse than the control, and this correlates with the relatively poor Performance of PVP and PVP/PVI in the washing machine. In accordance with the invention the inclusion of anionic monomers in the co-polymer of PVI has significantly reduced its tendency to interact with soil, whilst not affecting its ability to bind dyes in solution. Redeposition performance The redeposition performance of the polymers of the invention was investigated by evaluating their ability to prevent the transfer of iron oxide form prestained fabric on to clean cotton monitor cloths. (0.5 mis of a 1% dispersion of iron ( III ) oxide was pipetted onto each monitor cloth and allowed to dry overnight) . Experiments were conducted in a tergotometer at 60rpm, 40 c, lO in using demineralised water. The reflectance of the monitor cloths was measured as in Example 1 and delta E values calculated. The formulation was : lg/1 nonionic surfactant (E07) 0.87g/L STP 0.522g/L sodium carbonate 0.l305g/L g co-polymer (absent for the control] Table 3 There is thus a clear benefit for PVI/AA polymers. Example 5 - Dye solubilisation Without wishing to be bound by theory, it is desirable for the polymers of the invention to have lower solubilising capacities compared to the homopolymers of the dye scavenging monomers. Orange OT, a sparingly water soluble dye from Aldrich, was purified by recrystalising twice from a water/ethanol mixture. This purified dye was then dissolved in acetone (lOmg/ml) . 30ul (=0.3mg dye) of this solution was added to a vial containing water. The other components were then added: 0 . 2 5g/l active (a combination of LAS and non-ionic) , 0.522g/l Na 2 C0 3 , 0.87g/l STP and 0.1088g/l polymer (absent for the control). T he total solution was lOmls made with demin water. The vials containing the solutions were then shaken for 24 hours at 30°C. They were then centrifuged at 13,000 rpm for 10 mins to separate out the undissolved dye. The absorbance of the solutions was measured on a Perkin-Elmer Lambda 16 spectrophotometer at 492nm. In the table below Dye solubilised refers to the increase in absorbance of solutions (492nm) due to additional dye solubilised compared to the control without polymer. Table 4 The results clearly show that the incorporation of anionic groups in the polymer has depressed the ability of the polymer-surfactant complexes to solubilise the water insoluble dye. Examples 11 and 12 A liquid detergent composition was prepared having the following composition. Table 5 -31 - Example 13 Table 6 The following powdered compositions were prepared. Table 7 The formulations of Tables 5,6 and 7 had excellent cleaning and detergency performances with outstanding colour: care performance on coloured fabrics and mixed loads of coloured and white fabrics. Example (14) ,- Anti redeposition results for a copolymer of MeVI/VP/AA. The anti-redeposition properties of co-polymers comprising 50/50 MeVI/PVP dye-binding monomers and between 1 and 10% AA was tested following the method used above under the heading "Redeposition Performance" . The tests were repeated to check the accuracy (Rep 1 and Rep 2) . This time carbon black, not an iron compound, was used. Tests A, B and C below refer to the formulation in which the anti-redeposition properties of the polymer was tested. The control was the formulation in the absence of polymer. The MeVI/PVP/AA polymers were prepared following the method of Example 1. The method of EP-100-890 may also be used to produce the polymers. Tergotometer, 40°C, 10 mins, 60 rpm. Liquor: cloth 25:1 (270 mls:10.8g) Demin water 4 13x13 cm white mercerised cotton pieces l g/1 synperonic A7 (Syn A7) 0.87 g/1 zeolite A24 (MAP) 1.5 mis 1% dispersion of carbon black in 1 g/1 synperonic A7 The water and carbon black dispersion were placed in the tergo pot and agitated. The active and zeolite were then added followed by the cloth. They were washed for 10 mins and then rinsed twice in demin. They were then spun and tumble dried and their reflectance values measured as above. A) 1 g/1 Svn A7, 0.522 g/1 Na.CO-, , 0.87 g/1 zeolite 5.56 mls/1, 1% carbon black suspension, 25:1 liquor: cloth Polymer Delta E value of white monitor Rep 1 Rep 2 Control 1.4 1.26 MeVI/VP 50:50 1.32 1.14 MeVI/VP/AA 50 50 3 1.14 0.84 MeVI/VP 50:50 5 1.34 0.95 MeVI/VP/AA 50 50 7 0.98 0.71 MeVI/VP/AA 50 50 10 1.08 0.59 B) 1 g/1 Syn A7, 0.522 g/1 Na ^ CO-,, no builder Polymer Delta E value of white monitor Rep 1 Rep 2 Control 6.81 5.09 MeVI/VP 50:50 2.42 2.08 MeVI/VP/AA 50:50:1 2.47 2.07 MeVI/VP/AA 50:50:3 0.96 1.25 C) 1 g/1 Syn A7, 0.522 g/1 Na ^ CO, , no builder Polymer Delta E value of white monitor Rep 1 Control 7.54 MeVI/VP 50:50 5.65 MeVI/VP/AA 50:50:1 5.96 MeVI/VP/AA 50:50:3 0.36 Tests A, B and C all show the benefits for anti-redeposition achieved by the MeVI/VP/AA co-polymers. In particular the 3% and 7% AA exhibit excellent results. The anti-redeposition effect is achieved over a range of wash concentrations and both in the presence and absence of builder. (ii) Redeposition Screen The 50/50 MeVI/VP/AA co-polymers above were also tested as below. Shakerbath, 40°C 30 mins, 100 rpm. 100 mis wash solution prepared with Prenton water (26.4°F) . 150 mis HDPE bottles. 1 6x6cm Direct Red 80 test cloth. 2 lOxlOcm WFK10D test cloths . 1 13x13 cm white mercerised cotton. l g/1 80:20 LAS:NI (Petrelab 550:Synperonic A7) 0.522 g/1 Na2C03 0.87 g/1 STP 0.0218 g/1 polymer (=0.5% on formulation) The cloths, water, active and then polymer were placed in the poly bottle and then shaken for 30 mins. When the wash was complete the cloths were rinsed twice, spun dried and then tumbled. The reflectance values were measured on an ICS texicon Spectraflash 500 using the flash 500 programme. These were converted to Delta E values using the 4Optspec programme. Each wash was carried out in triplicate to minimise any experimental variation. Polymer E values of white monitors Rep 1 Rep 2 Rep 3 Average Control 14.81 12.66 10.23 12.57 MeVI/VP 15.74 14.88 15.18 15.27 50:50 MeVI/VP/AA 14.21 11.98 15.22 13.80 50:50:3 MeVI/VP/AA 10.96 12.96 13.63 12.52 50:50:5 MeVI/VP/AA 13.06 10.71 13.83 12.53 50:50:7 MeVI/VP/AA 8.94 13.99 12.83 11.92 50:50:10 The above table shows the good results for the anti- redeposition properties of the co-polymers. Example 15; MeVI/VP with AA in the presence of anionic and nonionic surfactants; dye transfer performance. MeVI/VP/AA polymers of varying MeVI/VP ratios and AA concentrations were tested in a surfactant active system of varying anionic/nonionic ratios (LAS:N1 ratio) . Conditions: Shakerbath, 40°C, 30 mins, 100 rpm. 100 mis solution made with 26.4°F water in 150 HDPE bottle. 1 g/1 total active (combination of LAS and nonionic) 0.52 g/1 NaC03 0.87 g/1 STP 10 uM Direct Red 80 dye 0.0435 g/1 polymer 13x13cm piece white mercerised cotton sheeting. The dye transfer performance was tested as detailed above under the heading "Dye Transfer Performance" . Polymer Delta E values of white monitors LAS:NI ratio 100:0 90:10 75:25 60:40 0:100 Control 39.8 41.18 40.11 40 39.44 MeVI/VP/AA 39.6 38.8 32.5 22.6 9.4 50:50:1 MeVI/VP/AA 38.9 37.52 30.75 21.88 15.73 50:50:3 MeVI/VP/AA 38.28 38.13 32.35 25.43 22.91 33:66:3 MeVI/VP/AA 38.32 36.23 32.22 29.05 29.73 25:75:3 The MeVI/VP/AA polymers containing 3% AA were found to give higher ΔE values and hence better performance across the range of anionic:nonionic (NI) ratios. In the predominantly nonionic surfactant systems particularly good results were obtained. Example 16; MeVI/VP with nonionic monomers. The dye transfer performance when PEG nonionic monomers were used was tested as for Example 15. Polymer Delta E values of white monitors LAS:NI ratio 100:0 90:10 75:25 60:40 0:100 Control 40.54 40.33 41.10 40.06 38.4 MeVI/VP/PEG (MW 40.35 38.13 34.77 25.67 7.85 300)50:50:5 MeVI/VP/PEG (MW 39.73 38.14 34.10 24.60 9.76 6000) 50:50:5 The two examples showed good results for dye transfer performance especially in the presence of larger ratios of nonionic surfactant ratios. Example 17,- VI copolymers with other anionic monomers. The dye transfer performance of co-polymers of VI with either octanioic acid or hexanoic acid monomers was tested using the method of Example 15 and following the method detailed under the heading "Dye Transfer Performance" . The control contained no co-polymer. Polymer Delta E values of white monitors LAS:NI ratio 100:0 90:10 75:25 60:40 0:100 Control 41.31 41.84 41.39 41.37 40.92 PVI/Octanoic 32.06 29.43 22.34 15.52 8.67 (94.4:5.6) PVI/Hexanoic 34.61 28.89 23.23 16.09 9.12 (92:8) Again the copolymers showed good dye-transfer inhibition performance especially in the presence of predominantly nonionic surfactant . Example 18; MeVI/VP with AA (50:50 with 3% AA) in a fabric softening composition. The following fabric softening composition was prepared. w/w Di -hardened tallow 5. .7 6 dimethyl ammonium chloride Varisoft 460 18 di (hardened 13.5 tallowoyloxy) eithyl dimethyl ammonium chloride Fatty acid 2 Perfume 0 .3 0.7 1.0 Co-polymer 0, .25 0.5 0.75 Water added balance balance balance Example 19; Granular Main Wash Detergent Compositions Comprising the Co-polymer Hand Wash Top ] Loading Front Loading %w/w %w/w %w/w NaLas 28 22 7 NI 0 2 3 Soap 0 2 4 STP 24 32 30 Carbonate 15 15 15 Zeolite 0 0 0 Sulphate 15.8 5.8 21.2 Silicate 8 8 8 Enzyme 0.6 1.0 0.6 Fluorescer 0.2 0.2 0.2 SCMC 1 1 1 Co-polymer 0.5 0.75 0.25 The VP/MeVI/AA (50:50 with 3% AA) was included in various washing compositions as above.

Claims: Claims 1. A detergent composition comprising a co-polymer and at least one component selected from surface active agents and fabric softening compounds, the co-polymer comprising at least one dye binding monomer and at least one anionic or nonionic monomer, with the proviso that the co-polymer is not poly (1-vinylpyrrolidone-co-acrylic acid). 2. A detergent composition according to claim 1 in which the anionic monomer of the copolymer is derived from acrylic acid, methacrylic acid, vinyl sulphonic acid, octanoic acid, hexanoic acid, itaconic acid, hydroxy acetic acid or mixtures thereof . 3. A detergent composition according to claim 1 in which the nonionic monomer is selected from polyethylene glycols. 4. A detergent composition according to any one of claims 1 to 3 in which the dye binding monomer (s) comprise (s) a nitrogen containing heterocycle. 5. A detergent composition according to claim 4 in which the dye binding monomer (s) is selected from vinyl imidazole, methyl vinyl imidazole, vinyl pyridine-N-oxide, vinyl pyrrolidone and mixtures thereof. 6. A detergent composition according to any preceding claim in which at least one dye binding monomer (s) are selected from vinyl imidazole, methyl vinyl imidazole and vinylpyrrolidone and the anionic monomer is acrylic acid. 7. A detergent composition according to any preceding clam in which the co-polymer is a co-polymer of poly (vinylpyrrolidone-co-polyvinylimidazole-co-acrylic acid) or a co-polymer of poly (vinylpyrrolidone-co- polyvinylimidazole-co-methacrylic acid) or poly ( vinylpyrrolidone-co-polymethylvinylimidazole-co- acrylic acid) or poly (vinylpyrrolidone-co-poly methyl vinyl imidazole-co-acrylic acid) . 8. A detergent composition according to claim 7 wherein the copolymer comprises 1-10% w/w acrylic acid or methacrylic acid and the weight ratio of vinyl pyrrolidone to vinylimidazole or methylvinylimidazole is within the range 90:10 to 10:90. 9. A detergent composition according to any preceding claim in which the molecular weight of the co-polymer is from 5,000 to 70,000. 10. A detergent composition according to any preceding claim in which the ratio of anionic monomer or nonionic monomer to the dye binding monomer within the co-polymer is from 1:100 to 1:3. 11. A detergent composition according to any preceding claim that comprises at least 2% w/w surface active agents and/or fabric softening agents. 12. A detergent composition according to any preceding claim wherein the surface active agent comprises a nonionic and/or anionic surfactant. 13. A detergent composition according to any preceding claim that further comprises a builder. 14. A dye binding co-polymer comprising at least one anionic monomer selected from acrylic acid, methacrylic acid, vinyl sulphonic acid, itaconic acid, octanoic acid, hexanoic, hydroxy acetic acid or mixtures thereof or at least one nonionic monomer selected from polyethylene glycols, and at least one dye binding monomer selected from vinyl imidazole, methyl vinyl imidazole, vinyl pyridine-N-oxide, vinyl pyrrolidone and mixtures thereof. 15. A dye binding co-polymer according to claim 14 wherein the co-polymer is a polymer of poly (vinylpyrrolidone-co- polyvinylimidazole-co-acrylic acid) or a co-polymer of poly (vinylpyrrolidone-co-polyvinylimidazole-co-methacrylic acid) or a co-polymer of poly (vinylpyrrolidone-co- polymethylvinylimidazole-co-acrylic acid) or a co-polymer of poly (vinylpyrrolidone-co-polymethylvinylimidazole-co- methacrylic acid. 16. Use of a co-polymer comprising at least one dye binding monomer and at least one anionic or nonionic monomer in a laundry treatment composition to mitigate dye transfer between fabrics . 17. Use according to claim 15 wherein the co-polymer is a dye binding co-polymer according to claim 14. 18. Use of a co-polymer as according to claim 14 to prevent anti-redeposition of soil in washing conditions wherein the polymer is of a type as according to claim 14..

Inventors: DIXON SARAH, KHOSHDEL EZAT, NEWGENT NICHOLAS, WARR JONATHAN FRANK, DIXON, SARAH, KHOSHDEL, EZAT, NEWGENT, NICHOLAS, WARR, JONATHAN, FRANK
Applicants: UNILEVER NV, UNILEVER PLC, UNILEVER N.V.
Application year: 1997
Main classification: C11D3
IPC codes: C08F226, C11D1, C11D3