WO2013092052A1 - Isotropic liquid detergents comprising soil release polymer - Google Patents

Abstract

An isotropic liquid detergent composition with an in-bottle pH in the range 6.0 to less than 7, the composition comprising, in addition to water: a) up to 60 wt% detersive surfactant including at least 5 wt% anionic sulphonate and /or sulphate surfactant comprising surfactant acid neutralised with one or more materials the pKa of whose conjugate acid(s) lies more than 2 units higher than the in-bottle pH of the detergent liquid composition b) at least 0.3 wt% fatty acid partially neutralised with one or more materials the pKa of whose conjugate acid(s) lies more than 2 units higher than the in-bottle pH of the detergent liquid composition c) at least 1.0 wt%, preferably at least 1.8 wt%, Triethanolamine (TEA); and d) at least 0.5 wt% soil release polymer (SRP).

Description

ISOTROPIC LIQUID DETERGENTS COMPRISING SOIL RELEASE POLYMER

TECHNICAL FIELD

This invention relates to isotropic liquid detergent compositions comprising water, hydrotrope, anionic sulphonate or sulphate surfactant and a polyester based soil release polymer. BACKGROUND

WO09153184 suggests that a laundry detergent liquid concentrate may be designed by replacing surfactant with a mixture of more weight efficient ingredients selected from polymers and enzymes. A preferred composition uses a combination of ethoxylated polyethylene imine (EPEI) and a polyester soil release polymer (SRP) to achieve excellent oily soil and particulate detergency at significantly lower in-wash surfactant levels than would normally be delivered from a high performance liquid. The exemplified compositions comprise anionic surfactant comprising linear alkyl benzene sulphonate neutralised with sodium hydroxide and further comprise soap formed by neutralisation of fatty acid by sodium hydroxide. The compositions are alkaline. It has been found that the SRP used for the examples suffers from alkaline hydrolysis and that this is catalysed by the use of triethanolamine (TEA) in the compositions. One obvious solution to the problem of the hydrolytic instability of the SRP is to divide the composition up and store it in separate compartments so the SRP does not come into contact with the TEA or alkalinity. Such acid based partial formulations could be based on the teaching in EP294893, US2010229313, and US3893929. However, the use of split compositions is not desirable as it adds cost and complexity. Consumers wish to have all the cleaning delivered from a single main wash liquid. There is considerable technical prejudice against formulating main wash liquids to be acidic. It is widely believed that they will produce acidic washing conditions which will lead to inadequate cleaning due to reduced performance of the surfactant system and possibly some of the enzymes. US5290475 (Colgate) is a document showing the technical prejudice against formulating under acidic conditions in order to increase the stability of the SRP. A liquid softening and antistatic nonionic detergent composition comprises as essential ingredients a nonionic detergent an anionic detergent a cationic fabric softener-anti-static agent and a soil release promoting polymer of a water-soluble fraction of the

polyethylene terephthalate-polyoxyethylene terephthalate type. To assist in the solubilising of the detergents and optical brighteners which may be present in the liquid detergents a small proportion of alkaline material or a mixture of such materials is often included. Suitable alkaline materials include mono-, di- and trialkanolamines, alkyl amines, ammonium hydroxide and alkali metal hydroxides. Of these the preferred materials are the alkanolamines, preferably the

trialkanolamines and of these especially triethanolamine. The pH of the final liquid detergent, containing such a basic material will usually be neutral or slightly basic. Satisfactory pH ranges are from 7 to 10, preferably about 7.5 to 9.5. WO9742286 (P&G) teaches on p3 that laundry detergents typically have a pH greater than 7.5. According to p9 SRP containing compositions it discloses have a pH of from about 7.2 to about 8.9 when measured as a 10% solution in water.

US4785060 (Colgate) discloses PET POET SRPs of high molecular weight made using a mixed catalyst system. These SRPs are said to retain their performance at high in wash pH in the presence of a detergency builder. They are taught to be included in both solid and liquid detergent compositions. The disclosure teaches to minimise the inclusion of alkanolamines such as TEA and ionisable salts such as Na. It is taught at column 10 lines 13 to 15 that it is preferred that the neutralizing agent employed, usually to increase the pH of the liquid detergent mixture, will be sodium hydroxide. At lines 17 to 18 it continues that "Triethanolamine salts and free triethanolamine should generally be avoided". The pH will be in the range of 6 to 10, preferably 6.1 to 8.9 and often more preferably 6.5 to 7.5. US4759876 (Colgate) discloses a soil release promoting liquid detergent composition comprising SRP The composition further comprises a stabilizing proportion of a stabilizer for enzyme(s) which also acts as a buffer for the liquid detergent composition to maintain the pH in a certain neutral or slightly acidic range to stabilize the SRP and the fluorescent brightener. It is said that the composition "substantially retains" its soil hydrolyzing fluorescent brightening and soil release promoting characteristics on storage so that laundry washed with it is effectively cleaned brightened and treated. However, US51 10506, from the same assignee, shows that the performance was not as good as suggested by '876. Furthermore it is clear from the disclosure in '876 that the pH drifts to acid on storage. We have determined that this is likely to be due to the breakdown of the SRP as it hydrolyses over a month of storage. No soap was included. The enzyme stabiliser/ buffer is said to keep the pH at 6.2 or higher. A pH range of 6.2 to 6.5 after storage is given. However, a further range of pH 5.8 to 7 is also given as one that does not destabilise the polymer.

In US51 10506 (Colgate) in addition to the revelation that the liquid of '876 gave poor soil release performance after storage it is taught that a small improvement in soil release performance after storage may be achieved by changing the nonionic to a special very expensive one which minimises 2EO and 3EO content. The liquid detergent is taught to have a pH in the range of 7.3 to 8.1 . This indicates that the pH is still drifting due to hydrolysis. The alleged improvement in cleaning is probably due to the switch to the more effective type of nonionic surfactant. GB1466639 (P&G) discloses detergent liquids with ethanolamine neutralised surfactant and SRP. Some free TEA is included to keep the wash water alkaline. Two different types of liquids are disclosed. In the first type the specific nonionic surfactant selected gives sufficient physical stability of the composition. In the second type fatty acid (soap) is included to provide long term storage stability. Example 1 appears to be an example of the second type of composition. It comprises oleic acid TEA salt 1 .5% and SRP 5% (from table 1 ). This is found to be an alkaline composition.

US441 1831 (Purex) discloses a stable aqueous detergent composition having enhanced soil release properties and consisting essentially of SRP (with LAS and nonionic and a buffer sufficient to maintain the pH of the aqueous composition within the range of 5.0 to 9.0.pref 6.5 to 7.5. The examples used Zelcon 4780 SRP in a main wash composition comprising LAS and nonionic and pH adjusted to 7. SXS was used as hydrotrope. No TEA or soap is used in the examples. The disclosure teaches that the comparative liquids without buffer generate an acid pH on storage. The acid pH is said to be detrimental to brighteners. We understand that the acid pH is generated due to decomposition of the SRP. The solution adopted is to add a buffer to stabilise the pH. This will result in increased SRP decomposition due to the pH being more alkaline. The brightener may be protected and this seems to be the real aim of this disclosure. Suitable buffers are taught to include bicarbonates, orthophosphate borates and alkanolamine hydrochlorides.

US4713194 (P&G) discusses the vulnerability of SRP to degradation in alkaline environments and proposes to protect the SRP by enrobing if it is to be used in granular compositions, or by adjusting the product pH to be between 7.0 and 8.5 if it is to be used in liquid compositions. The examples contain coco fatty acid at high levels.

US6262007 (P&G) describes acidic detergent liquids which include SRP to reduce the increase of viscosity as the temperature drops. Some examples include TEA but not with hydrotrope or fatty acid. There is a need for concentrated liquid detergent compositions comprising SRP that give excellent cleaning even after prolonged storage.

SUMMARY OF THE INVENTION

According to the present invention there is provided an isotropic liquid detergent composition with an in-bottle pH in the range 6.0 to less than 7, the composition comprising, in addition to water:

a) up to 60 wt% detersive surfactant including at least 5 wt% anionic sulphonate and /or sulphate surfactant comprising surfactant acid neutralised with one or more materials the pKa of whose conjugate acid(s) lies more than 2 units higher than the in-bottle pH of the detergent liquid composition

b) at least 0.3 wt% fatty acid partially neutralised with one or more materials the pKa of whose conjugate acid(s) lies more than 2 units higher than the in-bottle pH of the detergent liquid composition

c) at least 1 .0 wt%, preferably at least 1 .8 wt%, Triethanolamine (TEA); and d) at least 0.5 wt% soil release polymer (SRP) Preferably the composition has an in-bottle pH of 6.3 to 6.7. By in-bottle we mean in whatever container or pack the liquid is stored. It could be a plastic pack in the form of a bottle, squeezable or rigid, stored upright or inverted, or a unit dose format such as a soluble pouch, or a sachet. Fatty acid provides buffering capacity but its inclusion leads to phase separation of acidic compositions at low temperature. Thus it can only be included at relatively low levels. It cannot be totally removed as material used to neutralise the anionic surfactant a), preferably sodium hydroxide or monsethanolamine (MEA), cannot stabilise the composition on its own. Preferably the fatty acid is saturated. Most preferably it is used in an amount of from 0.5 to 1 .5 wt%. Use of TEA aids the stability of the fatty acid and TEA is therefore included at as high a level as can be tolerated by the SRP. The amount of TEA is preferably up to 3.7 wt%, and most preferably lies in the range 2.0 to 3.5 wt%. Advantageously the one or more materials the pKa of whose conjugate acid(s) lies more than 2 units higher than the in-bottle pH of the detergent liquid

composition comprises 0.08 to 0.25 wt% NaOH and/or monoethanolamine (MEA), preferably 0.1 to 0.23 wt% (or MEA). This definition of the non-buffering component is intended to cover all common weak and strong bases which lie outside the buffering region of interest (mildly acidic: 6.0 to less than 7). Thus, the material used to neutralise anionic surfactant acid to make anionic surfactant a), which material the pKa of whose conjugate acid(s) lies more than 2 units higher than the in-bottle pH of the detergent liquid composition, does not act significantly as a buffer at the in-bottle pH at which the composition is stored. In contrast the TEA does act as a buffer at the mildly acidic in-bottle pH.

The SRP is of the type that deposits from a wash solution onto polyester. It preferably has a polyester substantive part formed by condensation of terephthalic acid ester and diol, preferably 1 ,2 propanediol, and further comprises an end cap hydrophilic part comprising repeat units of ethylene oxide capped with an alkyl group. It may be used in an amount of more than 0.5 wt% and may be present up to a level of 15 wt%. Mixtures of different SRPs may be used.

The liquid will typically comprise a hydrotrope. When used, the level of hydrotrope will be at least 5 wt%, preferably at least 9 wt%, more preferably at least 14 wt%. For cost reasons the amount of hydrotrope is preferably less than 25 wt% and most preferably less than 20 wt% of the compositions. A preferred hydrotrope is 1 ,2 propanediol (MPG). Advantageously the composition comprises at least 3, preferably at least 5 wt% ethoxylated polyethylene imine (EPEI) to improve particulate soil removal. DETAILED DESCRIPTION OF THE INVENTION

In addition to the essential features the compositions of the invention may contain other ingredients. Such ingredients include viscosity modifiers, foam boosting agents, preservatives (e.g. bactericides), pH buffering agents, polyelectrolytes, anti-shrinking agents, anti-wrinkle agents, anti-oxidants, sunscreens, anti- corrosion agents, drape imparting agents, anti-static agents and ironing aids, colorants, pearlisers and/or opacifiers, and shading dye. Aspects of the essential and optional aspects of the compositions are further described below.

The isotropic liquids The amount of detersive surfactant makes up at least 10 wt% of the total liquid composition, preferably it makes up from 12 to 60 wt%. The compositions according to the invention most preferably have total active detersive surfactant levels of at least 15 wt%. The compositions may be concentrated compositions designed to be added to a 10 litre wash in small doses that require them to be diluted in at least 500 times their own volume of water to form a main wash liquor comprising at most 0.5 g/l surfactant. They may also be concentrated compositions designed for hand wash or top loading automatic washing machines. In hand wash less water may be used and in top loading automatic washing machines a higher amount of water would normally be used. The dose of detergent liquid is adjusted accordingly to give similar wash liquor concentrations. Surfactants

Surfactants assist in removing soil from the textile materials and also assist in maintaining removed soil in solution or suspension in the wash liquor. Anionic or blends of anionic and nonionic surfactants are a preferred feature of the present invention. The amount of anionic surfactant is preferably at least 5 wt%.

Preferably, the anionic surfactant forms the majority of the non soap surfactant (a). Anionic

Preferred alkyi sulphonates are alkylbenzene sulphonates, particularly linear alkylbenzene sulphonates having an alkyi chain length of C₈-C-|₅. The counter ion for anionic surfactants is generally an alkali metal, typically sodium, although other counter-ions such as MEA, TEA or ammonium can be used.

Preferred linear alkyi benzene sulphonate surfactants are Detal LAS with an alkyi chain length of from 8 to 15, more preferably 12 to 14.

It is further desirable that the composition comprises an alkyi polyethoxylate sulphate anionic surfactant of the formula (I):

RO(C₂H₄0)_xS0₃ ^"M⁺ (I) where R is an alkyi chain having from 10 to 22 carbon atoms, saturated or unsaturated, M is a cation which makes the compound water-soluble, especially an alkali metal, ammonium or substituted ammonium cation, and x averages from 1 to 15.

Preferably R is an alkyi chain having from 12 to 16 carbon atoms, M is Sodium and x averages from 1 to 3, preferably x is 3; This is the anionic surfactant sodium lauryl ether sulphate (SLES). It is the sodium salt of lauryl ether sulphonic acid in which the predominantly C12 lauryl alkyl group has been ethoxylated with an average of 3 moles of ethylene oxide per mole.

Nonionic

Nonionic surfactants include primary and secondary alcohol ethoxylates, especially C₈-C₂o aliphatic alcohol ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the C10-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 alkyl polyglycosides, glycerol monoethers and polyhydroxy amides (glucamide). Mixtures of nonionic surfactant may be used. When included therein the composition contains from 0.2 wt% to 40 wt%, preferably 1 wt% to 20 wt%, more preferably 5 to 15 wt% of a non-ionic surfactant, such as alcohol ethoxylate, nonylphenol ethoxylate, alkylpolyglycoside, alkyldimethylamineoxide, ethoxylated fatty acid monoethanolamide, fatty acid monoethanolamide, polyhydroxy alkyl fatty acid amide, or N-acyl N-alkyl derivatives of glucosamine ("glucamides"). Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the C8-C20 aliphatic alcohols ethoxylated with an average of from 1 to 35 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.

Amine Oxide

The composition may comprise up to 10 wt% of an amine oxide of the formula:

R¹ N(O)(CH₂ R²)₂ In which R¹ is a long chain moiety each CH₂R² are short chain moieties. R² is preferably selected from hydrogen, methyl and -CH₂OH. In general R¹ is a primary or branched hydrocarbyl moiety which can be saturated or unsaturated, preferably, R¹ is a primary alkyl moiety. R¹ is a hydrocarbyl moiety having chain length of from about 8 to about 18.

Preferred amine oxides have R¹ is C₈-C ₈ alkyl, and R² is H. These amine oxides are illustrated by C12-14 alkyldimethyl amine oxide, hexadecyl dimethylamine oxide, octadecylamine oxide.

A preferred amine oxide material is Lauryl dimethylamine oxide, also known as dodecyldimethylamine oxide or DDAO. Such an amine oxide material is commercially available from Hunstman under the trade name Empigen® OB. Amine oxides suitable for use herein are also available from Akzo Chemie and Ethyl Corp. See McCutcheon's compilation and Kirk-Othmer review article for alternate amine oxide manufacturers.

Whereas in certain of the preferred embodiments R² is H, it is possible to have R² slightly larger than H. Specifically, R² may be CH₂OH, such as: hexadecylbis(2- hydroxyethyl)amine oxide, tallowbis(2-hydroxyethyl)amine oxide, stearylbis(2- hydroxyethyl)amine oxide and oleylbis(2- hydroxyethyl)amine oxide.

Preferred amine oxides have the formula:

O^" - N⁺(Me)₂R¹ (3) where R¹ is C ₂-ie alkyl, preferably C _2-14 alkyl; Me is a methyl group. Zwitterionic

Nonionic-free systems with up to 95 %wt LAS can be made provided that some zwitterionic surfactant, such as carbobetaine, is present. A preferred zwitterionic material is a carbobetaine available from Huntsman under the name Empigen® BB. Carbobetaines, improve particulate soil detergency in the compositions of the invention.

Preferred compositions comprise at least 1 wt% of amine oxide or carbobetaine or mixtures thereof.

Additional surfactants

Other surfactants than the preferred LAS, SLES, nonionic and amphoteric

(betaine and / or amine oxide) may be added to the mixture of detersive

surfactants. However cationic surfactants are preferably substantially absent.

Although less preferred, some alkyl sulphate surfactant (PAS) may be used, especially the non-ethoxylated C-12-15 primary and secondary alkyl sulphates. A particularly preferred material, commercially available from Cognis, is Sulphopon 1214G.

Other Polymer EPEI

A particularly preferred class of polymer for use in combination with the polyester soil release polymer (SRP) is ethoxylated polyethyleneimine (EPEI). Polyethylene imines are materials composed of ethylene imine units -CH2CH2NH- and, where branched, the hydrogen on the nitrogen is replaced by another chain of ethylene imine units. These polyethyleneimines can be prepared, for example, by polymerizing ethyleneimine in the presence of a catalyst such as carbon dioxide, sodium bisulphite, sulphuric acid, hydrogen peroxide, hydrochloric acid, acetic acid, and the like. Specific methods for preparing these polyamine backbones are disclosed in U.S. Pat. No. 2,182,306, Ulrich et al., issued Dec. 5, 1939; U.S. Pat. No. 3,033,746, Mayle et al., issued May 8, 1962; U.S. Pat. No. 2,208,095,

Esselmann et al., issued Jul. 16, 1940; U.S. Pat. No. 2,806,839, Crowther, issued Sep. 17, 1957; and U.S. Pat. No. 2,553,696, Wilson, issued May 21 , 1951 .

Preferably, the EPEI comprises a polyethyleneimine backbone of about 300 to about 10000 weight average molecular weight; wherein the modification of the polyethyleneimine backbone is intended to leave the polymer without

quaternisation and nonionic. Such nonionic EPEI may be represented as

PEI(X)YEO where X represents the molecular weight of the unmodified PEI and Y represents the average moles of ethoxylation per nitrogen atom in the

polyethyleneimine backbone. The ethoxylation may range from 9 to 40 ethoxy moieties per modification, preferably it is in the range of 16 to 26, most preferably 18 to 22.

When used the EPEI polymer is present in the composition preferably at a level of up to 25 wt%, and preferably at a level of at least 3 wt% more preferably from 4 to 15 wt% and most preferably at least 5 wt%. The ratio of non-soap surfactant to EPEI is from 2:1 to 7:1 , preferably from 3:1 to 6:1 , or even to 5:1 .

Other polymer types

In addition to the polyester soil release polymer there may be used dye transfer inhibition polymers, anti redeposition polymers and cotton soil release polymers, especially those based on modified cellulosic materials. Hydrotrope

In the context of this invention a hydrotrope is a solvent that is neither water nor conventional surfactant that aids the solubilisation of the surfactants and other components in the aqueous liquid to render it isotropic. Among suitable hydrotropes there may be mentioned as preferred: MPG (monopropylene glycol), glycerol, sodium cumene sulphonate, ethanol, other glycols, e.g. di propylene glycol, diethers and urea. In addition to a drift to a more acidic composition pH on storage, which we attribute to the hydrolysis of the SRP, we have also observed that the physical stability of the composition seems also to be improved when it contains a SRP that is susceptible to alkaline hydrolysis; in particular we have found that the SRP sold by Clariant under the trade name Texcare SRN170 is not stable when stored in an alkaline detergent composition and furthermore the inclusion of this polymer into a surfactant containing alkaline detergent composition provides a surprising reduction in composition viscosity. Even with freshly manufactured polymer we observed this effect. We believe that the SRP acts as a hydrotrope in the isotropic detergent liquid

Enzymes

It is preferable that at least one or more enzymes may be present in the compositions. Preferably at least two, more preferably at least three different classes of enzymes are used in combination.

Lipase

Lipase is a particularly preferred enzyme. The composition may comprise from about 50 to about 20000 LU/g of a lipase. Preferably at least 800LU/g. Preferred lipase enzymes include those of bacterial or fungal origin. Chemically modified or protein engineered mutants are included. Examples of useful lipases include lipases from Humicola, more preferably ones which comprise a polypeptide having an amino acid sequence which has at least 90% sequence identity with the wild-type lipase derived from Humicola lanuginose, most preferably strain DSM 4109. The amount in the composition is higher than typically found in liquid detergents. This can be seen by the ratio of non-soap surfactant to lipase enzyme, in particular. A particularly preferred lipase enzyme is available under the trademark Lipoclean™ from Novozymes. As noted above, suitable lipases include those of bacterial or fungal origin.

Chemically modified or protein engineered mutants are included. Examples of useful lipases include lipases from Humicola (synonym Thermomyces), e.g. from H. lanuginosa (T. lanuginosus) as described in EP 258 068 and EP 305 216 or from H. insolens as described in WO 96/13580, a Pseudomonas lipase, e.g. from P. alcaligenes or P. pseudoalcaligenes (EP 218 272), P. cepacia (EP 331 376), P. stutzeri (GB 1 ,372,034), P. fluorescens, Pseudomonas sp. strain SD 705 (WO 95/06720 and WO 96/27002), P. wisconsinensis (WO 96/12012), a Bacillus lipase, e.g. from B. subtilis (Dartois et al. (1993), Biochemica et

Biophysica Acta, 1 131 , 253-360), B. stearothermophilus (JP 64/744992) or B. pumilus (WO 91 /16422). As noted above the preferred ones have a high degree of homology with the wild-type lipase derived from Humicola lanuginose.

Other examples are lipase variants such as those described in WO 92/05249, WO 94/01541 , EP 407 225, EP 260 105, WO 95/35381 , WO 96/00292, WO 95/30744, WO 94/25578, WO 95/14783, WO 95/22615, WO 97/04079 and WO 97/07202.

Preferred commercially available lipase enzymes include Lipolase™ and Lipolase Ultra™, Lipex™ and Lipoclean™ (Novozymes A/S). In addition to, or as an alternative to, lipase one or more other enzymes may be present. Advantageously, the presence of relatively high levels of calcium in the

compositions of the invention has a beneficial effect on the turnover of certain enzymes, particularly lipase enzymes and preferably lipases from Humicola. The preferred lipases include first wash lipases derived from Humicola lanuginosa strain DSM 4109 available under the Lipex™ brand from Novozymes. A similar enzyme from Novozymes but believed to fall outside of the above definition is sold by Novozymes under the name Lipoclean™ and this is also preferred. Phospholipase:

The method of the invention may be carried out in the presence of phospholipase classified as EC 3.1 .1 .4 and/or EC 3.1 .1 .32. As used herein, the term

phospholipase is an enzyme which has activity towards phospholipids.

Phospholipids, such as lecithin or phosphatidylcholine, consist of glycerol esterified with two fatty acids in an outer (sn-1 ) and the middle (sn-2) positions and esterified with phosphoric acid in the third position; the phosphoric acid, in turn, may be esterified to an amino-alcohol. Phospholipases are enzymes which participate in the hydrolysis of phospholipids. Several types of phospholipase activity can be distinguished, including phospholipases A and A₂ which hydrolyze one fatty acyl group (in the sn-1 and sn-2 position, respectively) to form

lysophospholipid; and lysophospholipase (or phospholipase B) which can hydrolyze the remaining fatty acyl group in lysophospholipid. Phospholipase C and phospholipase D (phosphodiesterases) release diacyl glycerol or

phosphatidic acid respectively.

Protease:

Suitable proteases include those of animal, vegetable or microbial origin. Microbial origin is preferred. Chemically modified or protein engineered mutants are included. The protease may be a serine protease or a metallo protease, preferably an alkaline microbial protease or a trypsin-like protease. Preferred commercially available protease enzymes include Alcalase™, Savinase™, Primase™,

Duralase™, Dyrazym™, Esperase™, Everlase™, Polarzyme™, and Kannase™, (Novozymes A/S), Maxatase™, Maxacal™, Maxapem™, Properase™,

Purafect™, Purafect OxP™, FN2™, and FN3™ (Genencor International Inc.).

Cutinase:

The method of the invention may be carried out in the presence of cutinase.

classified in EC 3.1 .1 .74. The cutinase used according to the invention may be of any origin. Preferably cutinases are of microbial origin, in particular of bacterial, of fungal or of yeast origin.

Amylase:

Suitable amylases (alpha and/or beta) include those of bacterial or fungal origin. Chemically modified or protein engineered mutants are included. Amylases include, for example, alpha-amylases obtained from Bacillus, e.g. a special strain of B. licheniformis, described in more detail in GB 1 ,296,839, or the Bacillus sp. strains disclosed in WO 95/026397 or WO 00/060060. Commercially available amylases are Duramyl™, Termamyl™, Termamyl Ultra™, Natalase™,

Stainzyme™, Fungamyl™ and BAN™ (Novozymes A/S), Rapidase™ and

Purastar™ (from Genencor International Inc.). Cellulase:

Suitable cellulases include those of bacterial or fungal origin. Chemically modified or protein engineered mutants are included. Suitable cellulases include cellulases from the genera Bacillus, Pseudomonas, Humicola, Fusarium, Thielavia, Acremonium, e.g. the fungal cellulases produced from Humicola insolens,

Thielavia terrestris, Myceliophthora thermophila, and Fusarium oxysporum disclosed in US 4,435,307, US 5,648,263, US 5,691 ,178, US 5,776,757, WO 89/09259, WO 96/029397, and WO 98/012307. Commercially available cellulases include Celluzyme™, Carezyme™, Endolase™, Renozyme™ (Novozymes A/S), Clazinase™ and Puradax HA™ (Genencor International Inc.), and KAC-500(B)™ (Kao Corporation).

Peroxidases/oxidases :

Suitable peroxidases/oxidases include those of plant, bacterial or fungal origin. Chemically modified or protein engineered mutants are included. Examples of useful peroxidases include peroxidases from Coprinus, e.g. from C. cinereus, and variants thereof as those described in WO 93/24618, WO 95/10602, and WO 98/15257. Commercially available peroxidases include Guardzyme™ and

Novozym™ 51004 (Novozymes A/S).

Pectate Lyases:

Pectate lyases (also called polygalacturonate lyases): Examples of pectate lyases include pectate lyases that have been cloned from different bacterial genera such as Erwinia, Pseudomonas, Klebsiella and Xanthomonas, as well as from Bacillus subtilis (Nasser et al. (1993) FEBS Letts. 335:319-326) and Bacillus sp. YA-14 (Kim et al. (1994) Biosci. Biotech. Biochem. 58:947-949). Purification of pectate lyases with maximum activity in the pH range of 8-10 produced by Bacillus pumilus (Dave and Vaughn (1971 ) J. Bacteriol. 108:166-174), B. polymyxa (Nagel and Vaughn (1961 ) Arch. Biochem. Biophys. 93:344-352), B. stearothermophilus (Karbassi and Vaughn (1980) Can. J. Microbiol. 26:377-384), Bacillus sp.

(Hasegawa and Nagel (1966) J. Food Sci. 31 :838-845) and Bacillus sp. RK9 (Kelly and Fogarty (1978) Can. J. Microbiol. 24:1 164-1 172) have also been described. Any of the above, as well as divalent cation-independent and/or thermostable pectate lyases, may be used in practicing the invention. In preferred embodiments, the pectate lyase comprises the pectate lyase disclosed in Heffron et al., (1 995) Mol. Plant-Microbe Interact. 8: 331 -334 and Henrissat et al., (1 995) Plant Physiol. 1 07: 963-976. Specifically contemplated pectate lyases are disclosed in WO 99/27083 and WO 99/27084. Other specifically contemplated pectate lyases (derived from Bacillus licheniformis) are disclosed in US patent no. 6,284,524 (which document is hereby incorporated by reference). Specifically contemplated pectate lyase variants are disclosed in WO 02/006442, especially the variants disclosed in the Examples in WO 02/006442 (which document is hereby incorporated by reference). Examples of commercially available alkaline pectate lyases include BIOPREP™ and SCOURZYME™ L from Novozymes A/S, Denmark.

Mannanases: Mannanase: Examples of mannanases (EC 3.2.1 .78) include mannanases of bacterial and fungal origin. In a specific embodiment the mannanase is derived from a strain of the filamentous fungus genus Aspergillus, preferably Aspergillus niger or Aspergillus aculeatus (WO 94/25576). WO 93/24622 discloses a mannanase isolated from Trichoderma reseei. Mannanases have also been isolated from several bacteria, including Bacillus organisms. For example, Talbot et al., Appl. Environ. Microbiol., Vol.56, No. 1 1 , pp. 3505-3510 (1 990) describes a beta-mannanase derived from Bacillus stearothermophilus. Mendoza et al., World J. Microbiol. Biotech., Vol. 1 0, No. 5, pp. 551 -555 (1 994) describes a beta- mannanase derived from Bacillus subtilis. JP-A-03047076 discloses a beta- mannanase derived from Bacillus sp. JP-A-63056289 describes the production of an alkaline, thermostable beta-mannanase. JP-A-63036775 relates to the Bacillus microorganism FERM P-8856 which produces beta-mannanase and beta- mannosidase. JP-A-08051 975 discloses alkaline beta-mannanases from

alkalophilic Bacillus sp. AM-001 . A purified mannanase from Bacillus

amyloliquefaciens is disclosed in WO 97/1 1 1 64. WO 91 Ιλ 8974 describes a hemicellulase such as a glucanase, xylanase or mannanase active. Contemplated are the alkaline family 5 and 26 mannanases derived from Bacillus agaradhaerens, Bacillus licheniformis, Bacillus halodurans, Bacillus clausii, Bacillus sp., and Humicola insolens disclosed in WO 99/64619. Especially contemplated are the Bacillus sp. mannanases concerned in the Examples in WO 99/64619.

Examples of commercially available mannanases include Mannaway™ available from Novozymes A/S Denmark. The enzyme and any perfume/fragrance or pro-fragrance present may show some interaction and should be chosen such that this interaction is not negative. Some negative interactions may be avoided by encapsulation of one or other of enzyme and pro-fragrance and/or other segregation within the product. Enzyme Stabilizers:

Any enzyme present in the composition may be stabilized using conventional stabilizing agents, e.g., a polyol such as propylene glycol or glycerol, a sugar or sugar alcohol, lactic acid, boric acid, or a boric acid derivative, e.g., an aromatic borate ester, or a phenyl boronic acid derivative such as 4-formylphenyl boronic acid, and the composition may be formulated as described in e.g. WO 92/19709 and WO 92/19708.

Liqnin compounds:

When a lipase enzyme is included a lignin compound may be used in the composition in an amount that can be optimised by trial and error. Lignin is a component of all vascular plants, found mostly between cellular structures but also within the cells and in the cell walls. Preferably the lignin compound comprises a lignin polymer and more preferably it is a modified lignin polymer. A modified lignin polymer as used herein is lignin that has been subjected to a chemical reaction to covalently attach chemical moieties to the lignin. The attached chemical moieties are preferably randomly substituted.

Preferred modified lignin polymers are lignins that have been substituted with anionic, cationic or alkoxy groups, or mixtures thereof. Preferably the substitution occurs on the aliphatic portion of the lignin and is random. Preferably the modified lignin polymer is substituted with an anionic group, and preferably it is a sulfonate. A preferred cationic group is a quanternary amine. Preferred alkoxy groups are polyalkylene oxide chains having repeat units of alkoxy moieties in the range from 5 to 30, most preferably ethoxy. Preferably the modified lignin sulfonate is substituted with anionic or alkoxy groups. Modified lignin polymers are discussed in WO/2010/033743. Most preferably the modified lignin polymer is lignin sulfonate (lignosulfonate). Lignin sulfonate may be obtained by the Howard process.

Exemplary lignin sulfonate may be obtained from a variety of sources including hardwoods, softwoods and recycling or effluent streams. The lignin sulfonate may be utilized in crude or pure forms, e.g., in an "as is" or whole liquor condition, or in a purified lignin sulfonate form from which or in which sugars and other saccharide constituents have been removed or destroyed, or from which or in which inorganic constituents have been partially or fully eliminated. The lignin sulfonate may be utilized in salt forms including calcium lignin sulfonate, sodium lignin sulfonate, ammonium lignin sulfonate, potassium lignin sulfonate, magnesium lignin sulfonate and mixtures or blends thereof.

The lignin sulfonate preferably has a weight average molecular weight of from 2000 to 100000. Their basic structural unit is phenylpropane. The degree of sulfonation is preferably from 0.3 and 1 .0 sulfate groups per phenylpropane unit. Lignin sulfonate are available from a number of suppliers including Borregaard LignoTech, Georgia-Pacific Corporation, Lenzing AG and Tembec Inc.

Lignin sulfonates are discussed in Lauten, R. A., Myrvold, B. O. and Gundersen, S. A. (2010) New Developments in the Commercial Utilization of Lignosulfonates, in Surfactants from Renewable Resources (eds M. Kjellin and I. Johansson), John Wiley & Sons, Ltd, Chichester, UK.

Fluorescent Agents: It may be advantageous to include fluorescer in the compositions. Usually, these fluorescent agents are supplied and used in the form of their alkali metal salts, for example, the sodium salts. The total amount of the fluorescent agent or agents used in the composition is generally from 0.005 to 2 wt %, more preferably 0.01 to 0.5 wt %.

Preferred classes of fluorescer are: Di-styryl biphenyl compounds, e.g. Tinopal (Trade Mark) CBS-X, Di-amine stilbene di-sulphonic acid compounds, e.g. Tinopal DMS pure Xtra and Blankophor (Trade Mark) HRH, and Pyrazoline compounds, e.g. Blankophor SN.

Preferred fluorescers are: sodium 2 (4-styryl-3-sulfophenyl)-2H-napthol[1 ,2- d]triazole, disodium 4,4'-bis{[(4-anilino-6-(N methyl-N-2 hydroxyethyl) amino 1 ,3,5- triazin-2-yl)]amino}stilbene-2-2' disulfonate, disodium 4,4'-bis{[(4-anilino-6- morpholino-1 ,3,5-triazin-2-yl)]amino} stilbene-2-2' disulfonate, and disodium 4,4'- bis(2-sulfoslyryl)biphenyl.

Bleach Catalyst:

Detergent compositions according to the invention may comprise a weight efficient bleach system. Such systems typically do not utilise the conventional

percarbonate and bleach activator approach. The present invention may be used in a formulation that is used to bleach via air, or an air bleach catalyst system. Suitable complexes and organic molecule (ligand) precursors for forming complexes are available to the skilled worker, for example, from: WO 98/39098; WO 98/39406, WO 97/48787, WO 00/29537; WO 00/52124, and WO00/60045, incorporated by reference. An example of a preferred catalyst is a transition metal complex of MeN4Py ligand (N,N-bis(pyridin- 2-yl-methyl)-1 -,1 -bis(pyridin-2-yl)-1 -aminoethane). Suitable bispidon catalyst materials and their action are described in WO02/48301 . Photobleaches may also be employed. In the context of the present invention a "photobleach" is any chemical species that forms a reactive bleaching species on exposure to sunlight, and preferably is not permanently consumed in the reaction. Preferred photo-bleaches include singlet oxygen photo-bleaches and radical photo-bleaches. Suitable singlet oxygen photo-bleaches may be selected from, water soluble phthalocyanine compounds, particularly metallated phthalocyanine compounds where the metal is Zn or AI-Z1 where Z1 is a halide, sulphate, nitrate, carboxylate, alkanolate or hydroxyl ion. Preferably the phthalocyanin has 1 -4 SO₃X groups covalently bonded to it where X is an alkali metal or ammonium ion. Such compounds are described in WO2005/014769 (Ciba).

When present, the bleach catalyst is typically incorporated at a level of about 0.0001 to about 10wt%, preferably about 0.001 to about 5wt%.

To reduce or prevent unwanted interaction with other liquid ingredients the catalyst may be protected, for example by encapsulation.

Perfume

Given that the composition of the present invention is designed to be used at very low levels of product dosage, it is advantageous to ensure that perfume is employed efficiently. A particularly preferred way of ensuring that perfume is employed efficiently is to use an encapsulated perfume. Use of a perfume that is encapsulated reduces the amount of perfume vapour that is produced by the composition before it is diluted. This is important when the perfume concentration is increased to allow the amount of perfume per wash to be kept at a reasonably high level.

It is even more preferable that the perfume is not only encapsulated but also that the encapsulated perfume is provided with a deposition aid to increase the efficiency of perfume deposition and retention on fabrics. The deposition aid is preferably attached to the encapsulate by means of a covalent bond,

entanglement or strong adsorption, preferably by a covalent bond or

entanglement.

Shading dyes

Shading dye can be used to improve the performance of the compositions used in the method of the present invention. The deposition of shading dye onto fabric is improved when they are used in compositions of the invention and according to the process of the invention. Preferred dyes are violet or blue. It is believed that the deposition on fabrics of a low level of a dye of these shades, masks yellowing of fabrics. A further advantage of shading dyes is that they can be used to mask any yellow tint in the composition itself.

Suitable and preferred classes of dyes are as described in WO09/153184.

Shading dye can be used in the absence of fluorescer, but it is especially preferred to use a shading dye in combination with a fluorescer, for example in order to reduce yellowing due to chemical changes in adsorbed fluorescer. Builders and sequestrants

The detergent compositions may also optionally contain relatively low levels of organic detergent builder or sequestrant material. Examples include the alkali metal, citrates, succinates, malonates, carboxymethyl succinates, carboxylates, polycarboxylates and polyacetyl carboxylates. Specific examples include sodium, potassium and lithium salts of oxydisuccinic acid, mellitic acid, benzene

polycarboxylic acids, and citric acid. Other examples are DEQUEST™, organic phosphonate type sequestering agents sold by Thermphos and alkanehydroxy phosphonates. A particularly preferred sequestrant is HEDP sold by Thermphos as Dequest® 2010 and also known as 1 -Hydroxyethylidene -1 , 1 ,-diphosphonic acid. Also suitable, but less preferred is Dequest® 2066 (Diethylenetriamine penta(methylene phosphonic acid or Heptasodium DTPMP). Other suitable organic builders include the higher molecular weight polymers and copolymers known to have builder properties. For example, such materials include appropriate polyacrylic acid, polymaleic acid, and polyacrylic/polymaleic acid copolymers and their salts, such as those sold by BASF under the name

SOKALAN™.

If utilized, the organic builder materials may comprise from about 0.5% to 20 wt%, preferably from 1 wt% to 10 wt%, of the composition. The preferred builder level is less than 10 wt% and preferably less than 5 wt% of the composition. External Structurants

The compositions may have their rheology modified by use of a material or materials that form a structuring network within the composition. Suitable structurants include hydrogenated castor oil, microfibrous cellulose and natural based structurants such as citrus pulp fibre. Citrus pulp fibre is particularly preferred especially if lipase enzyme is included in the composition. Visual Cues

The compositions may, and preferably do, comprise visual cues of solid material that is not dissolved in the composition. Preferably they are used in combination with an external structurant to ensure that they remain in suspension. Preferred visual cues are lamellar cues formed from polymer film and possibly comprising functional ingredients that may not be as stable if exposed to the alkaline liquid. Enzymes and bleach catalysts are examples of such ingredients. Also perfume, particularly microencapsulated perfume.

Packaging and dosing

The liquids may be packaged as unit doses in polymeric film adapted to be insoluble until added to the wash water. More preferred the liquids are supplied in multiuse plastics packs with a top or bottom closure. A dosing measure may be supplied with the pack either as a part of the cap or as an integrated system.

Method of use Following the teaching in WO2009/153184 the liquids according to the invention are intended to be formulated to allow them to be dosed to a typical front loading automatic washing machine at a dosage level of 20ml. The low in wash surfactant level being compensated by the presence of enzymes, the stable soil release polymer and optional additional high efficacy cleaning ingredients, such as EPEI. However, the invention is also suitable for the more conventional dosage levels of about 35 ml. To obtain suitable liquids of this type all that is necessary is to add further water and possibly perfume to the 20ml type of liquid. The soil release polymers claimed are also stable in these more dilute compositions. The invention will now be further described with reference to the following non- limiting examples. EXAMPLES

In the following examples the key to the material abbreviations is as follows:

MPG is mono propylene glycol,

TEA is triethanolamine.

Nl 7EO is C12-15 alcohol ethoxylate 7EO nonionic

Neodol® 25-7 (ex Shell Chemicals).

LAS acid is C12-14 linear alkylbenzene sulphonic acid.

Prifac® 5908 is saturated lauric fatty acid ex Croda.

SLES 3EO is sodium lauryl ether sulphate with 3 moles EO.

Empigen® BB is an alkyl betaine ex Huntsman (Coco dimethyl

carbobetaine).

EPEI is Sokalan HP20 - ethoxylated polyethylene imine

cleaning polymer: PEI(600) 20EO ex BASF.

Perfume is free oil perfume.

SRP is soil release polymer.

Prifac® 5908 is saturated lauric fatty acid ex Croda.

MEA is Monoethanolamine.

NaOH is 47% sodium hydroxide solution.

Dequest® 2066 is Diethylenetriamine penta(methylene phosphonic acid

(or Heptasodium DTPMP).

Dequest® 2010 is HEDP (1 -Hydroxyethylidene -1 ,1 ,-diphosphonic acid). Lipex® is Lipex 100L ex Novozymes.

Carezyme® is a cellulase ex Novozymes.

Stainzyme 12L is an amylase formulated for liquids ex Novozymes.

Mann away is a mannanase ex Novozymes.

All tergo experiments have 2-prewashes and a main wash. The DMO stain is applied after the second prewash. The load is 50:50 knitted polyester / woven cotton at a liquor to cloth ratio of 25:1 . A 30 minute wash is conducted using an RPM of 100. · E ~ 5-10 is excellent removal of the DMO stain; · E ~ 37 is equivalent to performance in the absence of SRP; · E ~ 50 is equivalent to the stain before washing. SRP hydrolytic stability (based on cleaning performance of a DMO marker stain on polyester) of composition 1 given in Table 1 with variation of pH due to the dose of Sodium hydroxide is recorded in Table 2. A smaller value for · E means better stain removal. Before washing the compositions had been stored at 37°C for 8 weeks to give an indication of the resistance of the SRP to prolonged storage in-bottle.

Table 1 - Composition 1 - variation of pH

Raw Material % (as 100%)

Demin water to 100%

MPG 20

NaOH 0

TEA 2

Nl 7EO 12.74

LAS acid 8.49

Prifac 5908 1 .5

SLES 3EO 4.24

Empigen BB 1 .5

EPEI 5.5

SRP 3.75

Perfume 2.43

pH adjustment hole 10

Table 2- effect of storage H on cleaning

At pH 6.5 and 6.75 good performance is observed with 2 and 3.5 wt% TEA, suggesting acceptable SRP stability. So a target pH of 6.5 and upper limit of pH less than 7.0 with up to 3.5 wt% TEA is preferred for a composition as shown in table 1 . For a similar composition diluted with water to 1 .5 times the volume the same pH range is needed for stability and may be achieved with the

correspondingly lower level of 2 wt% TEA (i.e. pro rata).

Buffering control

A detergent liquid should be pH robust on a plus or minus 5 wt% ingredient to allow for manufacturing variability. To obtain that robustness it is necessary to include buffer into the liquid. The buffers used are TEA (pKa 7.8) and Prifac 5908 fatty acid (pKa unknown because it is a mixture).

In WO09153184 3% Prifac 5908 was used. At this level the fatty acid has a direct impact on low temperature instability, consequently the level of fatty acid has been reduced to improve the low temperature stability (in 20 ml liquid to 1 .71 % and correspondingly 0.85% for 35 ml compositions). The impact on antifoaming was checked and found to be acceptable. The impact of reduced Prifac 5908 on buffering and pH control was also checked with the 20ml compositions given in table 3 and found to be acceptable (table 4).

Table 3

Table 4 - pH robustness check for Table 3 liquid as a function of TEA level

Table 3 liquid with

3.5 wt% TEA 1 wt% TEA 0 wt% TEA 1.5% Prifac 5908

pH (target pH pH (target pH pH (target pH +/-5 wt% ingredient

= 6.5) = 6.5) = 6.5)

check

Target 6.51 6.54 6.50

+5% LAS acid 6.1 1 6.05 5.77

-5% LAS acid 6.63 6.75 6.68

+5% TEA 6.59 6.55 —

-5% TEA 6.28 6.34 —

+5% NaOH 6.66 6.66 6.69

-5% NaOH 6.35 6.18 5.85

+5% Prifac 5908 6.38 6.47 6.22

-5% Prifac 5908 6.5 6.47 6.33

Overall pH range 6.1 - 6.7 6.0 - 6.8 5.7 - 6.7 The liquid of table 3 has no pH control if there is no Prifac 5908 or TEA.

Acceptable pH control can be achieved with 1 .5% Prifac 5908 and at least 1 % TEA. With 0% TEA the upper pH region is controlled but the lower pH region drops to significantly below pH 6.0 which results in unacceptable low temperature stability performance.

Low temperature stability

The two low temperature criteria are robustness at 5°C (with recovery at ambient) for up to 12-weeks and freeze/thaw (with recovery at ambient) for 1 -week.

The level of fatty acid used is a key aspect of low temperature instability and this is made increasingly worse at lower pHs (as the ratio of fatty acid to soap is increased). The addition of TEA and MPG can overcome this instability if added at the required levels.

The starting point for the 20 ml liquid composition based on SRP hydrolytic stability and pH control is a target pH of 6.5 with a minimum of 1 % TEA and 1 .5% Prifac 5908. The actual TEA requirement is defined in table 5 and the MPG requirement is defined in table 6.

The preferred wt% TEA is 3.5% and the preferred wt% MPG is 20% for the liquid as defined in table 1 . The starting point for a more dilute 35ml composition is the same pH requirement and 2% TEA. The level of MPG required for low temperature stability is shown in table 7. The wt% MPG required is 15% for the 35 ml liquid. Table 5 - Composition 1 liquid low temperature stability with varying levels of TEA

F/T = freeze thaw

Table 6

Raw

%(as 100%)

Material

Demin water to 100%

MPG 10-25

NaOH to pH target

TEA 3.5

Nl 7EO 12.74

LAS acid 8.49

Prifac 5908 1.5

SLES 3EO 4.24

Empigen BB 1.5

EPEI 5.5

SRP 3.75

Perfume 1.39

Table 7 - Low temperature stability profile for Table 6 liquid as a function of pH and MPG level.

Table 8 - 35 ml isotropic liquid

pH range 6, 6.5, 7, 7.5, 8 Table 9 - stability data for composition of Table 8

P = Pass

F = Fail

R = Fail at 5°C, but becomes Isotropic on warming to RT

Claims

Claims

1 . An isotropic liquid detergent composition with an in-bottle pH in the range 6.0 to less than 7, the composition comprising, in addition to water:

a) up to 60 wt% detersive surfactant including at least 5 wt% anionic sulphonate and /or sulphate surfactant comprising surfactant acid neutralised with one or more materials the pKa of whose conjugate acid(s) lies more than 2 units higher than the in-bottle pH of the detergent liquid composition

b) at least 0.3 wt% fatty acid partially neutralised with one or more materials the pKa of whose conjugate acid(s) lies more than 2 units higher than the in-bottle pH of the detergent liquid composition

c) at least 1 .0 wt%, preferably at least 1 .8 wt%, Triethanolamine (TEA); and d) at least 0.5 wt% soil release polymer (SRP).

2. A composition according to claim 1 which has an in bottle pH of 6.3 to 6.7.

3. A composition according to any preceding claim in which the fatty acid is saturated.

4. A composition according to any preceding claim in which the fatty acid is used in an amount of from 0.5 to 1 .5 wt%.

5. A composition according to any preceding claim which comprises up to 3.7 wt% Triethanolamine (TEA), preferably 2.0 to 3.5 wt%.

6. A composition according to any preceding claim in which the one or more materials the pKa of whose conjugate acid(s) lies more than 2 units higher than the in-bottle pH of the detergent liquid composition comprises 0.08 to 0.25 wt% NaOH and or monoethanolamine (MEA), preferably 0.1 to 0.23 wt%.

7. A composition according to any preceding claim in which the SRP has a fabric substantive part formed by condensation of terephthalic acid ester and diol, preferably 1 ,2 propanediol, and further comprises an end cap hydrophilic part comprising repeat units of ethylene oxide capped with an alkyl group.

8. A composition according to any preceding claim in which the liquid comprises a hydrotrope in an amount of at least 5 wt%, preferably at least 9 wt% and more preferably at least 14 wt% and most preferably 1 ,2 propanediol (MPG).

9. A composition according to any preceding claim which comprises at least 5 wt% ethoxylated polyethylene imine (EPEI).

10. A composition according to any preceding claim in which the anionic surfactant a) comprises at least 5 wt% linear alkyl benzene sulphonate (LAS).