The present invention relates to deflocculating polymers and liquid detergent compositions comprising such polymers, in particular to liquid detergent compositions that comprise a dispersion of lamellar droplets in an aqueous continuous phase.

Background & Prior art Several types of deflocculating polymers are described in the art. EP 346 995 describes deflocculating polymers having a hydrophilic backbone and one or more hydrophobic side-chains, WO 91/06622 describes deflocculating polymers being a block copolymer consisting of alternating hydrophobic and hydrophilic groups, WO 91/06623 describes deflocculating polymers consisting of nonionic monomers and ionic monomers and GB 2 237 813 describes deflocculating polymers consisting of a hydrophobic backbone and one or more hydrophilic side-chains.

Deflocculating polymers have been used in liquid detergents, in particular in liquid detergent compositions that comprise a dispersion of lamellar droplets in an aqueous continuous phase, as for example described in EP 346 995, WO/91/06622, WO/91/06623 and GB 2 237 813. Other applications for deflocculating polymers in general purpose cleaners, liquid abrasive cleaners, liquid bleach compositions are disclosed in WO/91/09108, in fabric softening compositions in EP 415698 and the use in granular detergent compositions is disclosed in WO/91/09932.

WO/91/09109 discloses liquid detergent compositions comprising deflocculating polymers that are biodegradable.

As a consequence of consumers\' and manufacturers\' awareness for environmental issues, a trend can be seen to more development and more appreciation of "green" products, i.e.

products with ingredients that are biodegraded quicker and easier, i.e. to search for ingredients that will result in an improved biodegradability of products.

Surprisingly, applicants have found a way to improve the biodegradability of deflocculating polymers.

These improved polymers do not suffer from loss of the beneficial deflocculating effects in liquid or granular detergent compositions. The improvement can be established by inclusion of a particular group in the hydrophilic backbone of the polymer, resulting in the polymers becoming better biodegradable.

Definition of the invention

The present invention relates to a deflocculating polymer having a hydrophilic backbone and one or more hydrophobic side-chains, or being a block copolymer having alternating hydrophobic and hydrophilic groups, or having nonionic monomers and ionic monomers characterised in that the deflocculating polymer comprises from 1 to 30 mole % of monomer

O

I) units containing a ketone - C - group.

A second aspect of the invention relates to a liquid detergent composition comprising a dispersion of lamellar droplets of detergent active material in an aqueous continuous phase, characterised in that the composition comprises deflocculating polymer comprising from 1 to 30 mole %

0 /I of monomer units containing a ketone - C - group.

In general, the monomer units having a ketone group are of the formula:

O l! - CH2 - C - CH2 -

The deflocculating polymer comprises from 1 to 30 mole % of

O l\ monomer units containing a ketone - C - group, preferably 2-20 mole % of ketone groups, more preferably 5-10 mole % of ketone groups.

Deflocculating polvmer with hydrophilic backbone and one or more hydrophobic side-chains

Generally the hydrophilic backbone of the polymer is predominantly linear; the main chain or the backbone constitutes at least 50%, preferably more than 75%, most preferred more than 90% by weight of the polymer. Monomer units suitable for incorporation in the hydrophilic backbone are for example unsaturated C ₂ _ ₆ acids, ethers, alcohols, aldehydes or esters, sugar units, alkoxy units, maleic anhydride and saturated polyalcohols such as glycerol. Examples of suitable monomer units are acrylic acid, alpha hydroxy acrylic acid, alpha hydroxy methyl acrylic acid, methacrylic acid, maleic acid, vinyl acetic acid, itaconic acid, polyethoxy groups preferably comprising from 4 to 50 ethylene oxide groups, polyglycerol, condensation polymers of polyglycerol and citric acid anhydride and condensation polymers of alpha- hydroxy acids or polyacetals.

Each of the above monomers can be present in the hydrophilic backbone in random order, in block arrangement or in mixtures thereof.

The hydrophilic backbone made from the backbone constituents in the absence of hydrophobic side-groups is relatively water-soluble at ambient temperature and a pH of between 6.5 and 14.0. Preferably the solubility is more than 1 g/1, more preferred more than 5 g/1 most preferred more than 10 g/1.

Preferably the hydrophobic side chains are part of a monomer unit which is incorporated in the polymer by copolymerising hydrophobic monomers and the hydrophilic monomers making up the backbone of the polymer. The hydrophobic side chains for this use preferably include those which when isolated from their linkage are relatively water insoluble, i.e. preferably less than 1 g/1, more preferred less than 0.5 g/1, most preferred less than 0.1 g/1 of the hydrophobic monomers, will dissolve in water at ambient temperature and a pH of 3.0 to 12.5.

Examples of relatively hydrophobic groups are butylene oxide and/or propylene oxide and/or alkyl or alkenyl chains. The hydrophobic groups may be connected to the hydrophilic backbone directly or via relatively hydrophilic linkages for example a polyethoxy linkage.

Deflocculating polymer being a block copolymer having alternating hydrophobic and hydrophilic groups These polymers have one of the following general structures:

A -4B—. A-j— B— A or B — B-l-* A -*•-•B

wherein A represents a hydrophobic group, B a hydrophilic group and z is an integer which is preferably zero.

The hydrophilic groups of the polymer are preferably composed of hydrophilic monomer units, which can be

selected from a variety of units available for the preparation of polymers. Suitable hydrophilic monomer units are for instance described in the paragraph on deflocculating polymer with hydrophilic backbone and one or more hydrophobic side-chains. Particularly preferred hydrophilic groups are polyethoxy groups preferably comprising from 4 to 50 ethylene oxide groups, polyglycerol, condensation polymers of polyglycerol and citric acid anhydride and condensation polymers of alpha- hydroxy acids or polyacetals.

The hydrophobic groups of the polymer are preferably selected from saturated and unsaturated alkyl chains, e.g. having from 5 to 24 carbon atoms, preferably from 6 to 18, most preferred from 8 to 16 carbon atoms, and are optionally bonded to the adjacent hydrophilic groups via an alkoxylene or polyoxyalkylene linkage, for example a polypropoxy or butyloxy linkage having from 1 to 50 alkoxylene groups. Other suitable hydrophobic groups are polyoxyalkylene groups comprising from 4 to 50 propylene oxide and/or butylene oxide groups.

The hydrophilic groups may be linked to the hydrophobic groups by any possible chemical link, although the following types of linkages are preferred: -C-0-, -CO-O- or -0-.

Deflocculating polvmer with ionic and nonionic groups The ionic-nonionic deflocculating polymer comprises a monomer A which is independently selected from the group of monomer units which are nonionic under the conditions in the liquid detergent product and a monomer B which is ionic under the conditions of the product.

Embraced in the definition of nonionic monomer A units for use in compositions of the invention are monomers which are nonionic of character under most circumstances and monomer

units which are anionic or cationic of character, but which are at the conditions such as pH of the product neutralised such that they have an appreciable nonionic character. Preferably the pH of the product differs at least one unit, more preferred at least two units with the pK _a value corresponding to the neutralisation of the monomer unit in the polymer.

Suitable monomer units which are nonionic per se are for example ethylenically unsaturated amides such as acrylamide, methacrylamide and fumaride and their N- substitued derivatives such as N-(dimethyl amino ethyl)- acrylamide, vinyl alcohol, vinyl acetate, vinyl heterocyclic amides such as vinyl pyrrolidone, acrolein, allyl alcohol, hydroxy ethyl ( eth) acrylate, hydroxy propyl (meth)acrylate, sugar units such as saccharides and glucosides, glycerol or other polyalcohols.

Suitable monomer units which are anionic at certain conditions, but which have an appreciable nonionic character at relatively low pH values of the product are for example: ethylenically unsaturated carboxylic acids, dicarboxylic acids such as acrylic acid, maleic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, aconitic acid and citraconic acid.

Suitable monomer units which are cationic under certain conditions, but which have an appreciable nonionic character at relatively high pH values are for example: amino alkyl esters of unsaturated carboxylic acids such as 2-amino ethyl ( etha)crylate, dimethyl amino ethyl (meth)acrylate, diethyl amino ethyl (meth)acrylate, dimethyl amino methyl (meth) acrylate, diethyl amino ethyl (meth)acrylate, vinyl or alkyl amines such as vinyl pyridine, vinyl morpholine or allylamine.

Also mixtures of nonionic monomers may be used.

The ionic monomer B may be ionic under most circumstances, but also possible is the use of monomer units which only become ionised under the pH conditions of the product. If such ionisable monomer units are used, then preferably the pH of the product should differ at least one unit, more preferred at least two units with the pK _a corresponding to the ionisation of the monomer in the polymer.

Examples of generally ionised monomer units are N(trimethylammoniumethyl) acrylamide chloride or sulphate, N(trimethyl ammonium propyl) acrylamide chloride or sulphate, 2-suphato ethyl (meth)acrylate and its ammonium, alkali metal or alkali earth metal salts, or can be obtained by conversion reactions of monomers A such as the cationisation of sugar units with 2,3 epoxypropyl trimethyl ammonium chloride, other ethylenically unsaturated quaternary ammonium compounds such as vinyl benzyl trimethyl ammonium chloride, the quaternary ammonium salts of di methyl/ethyl amino methyl/ethyl (meth)acrylate, vinyl aryl sulphonates such as vinyl benzyl sulphonate, sodium vinyl sulphonate, sodium alkyl sulphonate, beta-styrene phosphonic acid, sodium-p styrene sulphonate and vinyl phosphonic acid. Examples of monomer units which have an appreciable ionised character at relativly high pH values are ethylenically unsaturated carboxylic acids, dicarboxylic acids such as acrylic acid, maleic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, aconitic acid and citralinic acid.

Suitable monomer units which which have an appreciable ionised character at relatively low pH values are for example: amino alkyl esters of unsaturated carboxylic acids such as 2-amino ethyl (metha)crylate, dimethyl amino ethyl (meth)acrylate, diethyl amino ethyl (meth)acrylate, dimethyl amino methyl (meth) acrylate, diethyl amino ethyl (meth)acrylate, vinyl or alkyl amines such as vinyl pyridine, vinyl morpholine or allylamine.

Also mixtures of monomer units may be used.

Preferably the monomers for use in ionic-nonionic polymers are sufficiently hydrophilic to form at least a 1 % by weight solution when dissolved in water of ambient temperature and of the pH of the final product.

Preferably ionic-nonionic polymers contain at least two different monomers. The first of these monomers is preferably of nonionic character as defined hereinabove, the second monomer is preferably ionic under most circumstances as defined hereinabove. Most preferably the ionic monomer is a cationic monomer. Preferably the amount of ionic monomers in the polymer is from 0.1 to 50 % by weight of the polymer, more preferred from 1 to 25%, most preferred from 4 to 15%.

Summary of the invention

A first group of preferred deflocculating polymers according to the present invention, having hydrophilic backbone and one or more hydrophobic side-chains, has the formula (I) :

wherein: the monomer units may be in random order; z is 1; k is at least 1; y preferably being from 0 up to the value of x; n is at least 1 (and can be determined by the molecular weight) ; the ratio of (k + x + y) : z is from 4 : 1 to 1,000 : 1, preferably from 6 : 1 to 250 : 1; the ratio of k : (x + y + z) is from 1:99 to 30:70, preferably from 2:98 to 20:80, more preferably from 5:95 to 10:90;

R ¹ represents -C0-0-, -0-, -0-C0-, -CH ₂ -, -CO-NH- or is absent;

R ² represents from 1 to 50 independently selected alkyleneoxy groups (preferably ethylene oxide or propylene oxide groups) , or is absent, provided that when R ³ is absent and R ⁴ represents hydrogen or contains no more than 4 carbon atoms, then R ² contains at least 1 alkyleneoxy group, preferably more than 3, more preferably more than 5 alkyleneoxy groups, the alkyleneoxy groups preferably having at least 3 carbon atoms;

R ³ represents a phenylene linkage, or is absent;

R ⁴ represents hydrogen or a C ₁ _ ₂₄ alkyl or C ₂ _ ₂₄ alkenyl group, with the provision that when R ² is absent, then R ⁴ is not hydrogen and when also R ³ is absent, then R ⁴ contains at least 2, preferably at least 3, more preferably at least 4, most preferably at least 5 carbon atoms. More preferably R ⁴ represents hydrogen or a C _j _ ₂₄ alkyl or ^c ₂ - ₂₄ alkenylk group, with the provisos that:

a) when R ¹ represents -0-CO-, R ² and R ³ must be absent and R4 must contain at least 5 carbon atoms;

b) when R ² is absent, R ⁴ is not hydrogen and when R ³ is absent, then R ⁴ must contain at least 5 carbon atoms.

R ⁵ represents hydrogen or a group of formula -C00A ⁴ ;

R ⁶ represents hydrogen or C*-^ alkyl; and

A ¹ , A ² , A ³ and A ⁴ are independently selected from hydrogen, alkali metals, alkaline earth metals, ammonium and a ine bases and C _± _ ₄ , or (C ₂ H ₄ 0) _t H wherein t is from 1-50, and wherein the monomer units may be in random order.

Each B ¹ is independently selected from -CH ₂ OH, -OH or -H;

For each monomer unit R ¹ -R ⁶ , A ¹ -A ⁴ and B ¹ may independently be selected from the groups mentioned above.

A second group of preferred deflocculating polymers of the present invention, having hydrophilic backbone and one or more hydrophobic side-chains, is of the formula (II) :

1Ϊ wherein: Q ² is a molecular entity of formula (Ila)

wherein: the monomer units may be in random order; z and v are 1; n is at least 1 (and can be determined from the molecular weight) ; k is at least 1; at least 1 of the monomer units p, q or r is present; the ratio of (k + x + y + p + q + r) : z is from 4 : 1 to

1,000 : 1, preferably from 6 : 1 to 250 : 1; the ratio of k : (x + y + p + q + r + z) is from 1:99 to 30:70, preferably from 2:98 to 20:80, more preferably from

5:95 to 10:90;

R ¹ -R ⁶ , A ¹ -A ⁴ and B ¹ are as defined as for formula I.

R ⁷ and R ⁸ represent -CH ₃ or -H;

R ⁹ and R ¹⁰ represent substituent groups such as amino, amine, amide, sulphonate, sulphate, phosphonate, phosphate, hydroxy, carboxyl and oxide groups, preferably they are selected from -S0 ₃ Na, -C0-0-C ₂ H ₄ -0S0 ₃ Na, -CO-O-NH-C(CH ₃ ) ~- S0 ₃ Na, -C0-NH ₂ , -0-CO-CH ₃ , -OH;

For each monomer unit R ¹ -R ¹² , A ¹ -A ⁴ and B ¹ may independently be selected from the groups mentioned above.

Q ¹ is a multifunctional monomer, allowing the branching of the polymer, wherein the monomers of the polymer may be connected to Q ¹ in any direction, in any order, therewith possibly resulting in a branched polymer. Preferably Q ¹ is trimethyl propane triacrylate (TMPTA) , methylene bisacrylamide or divinyl glycol.

A third group of preferred deflocculating polymers of the present invention, having hydrophilic backbone and one or more hydrophobic side-chains, and being especially suitable for fabric softening compositions comprising an aqueous base and one or more fabric-softening materials, is of the formula (III) :

wherein ³ is derived from a onomeric unit Ilia

X- - co prismg:

*

Q ⁴ is derived from the molecular entity Illb:

and Q ^b is derived from a monomeric unit IIIc:

wherein: n is at least 1; k is at least 1;

w is 0 to 4 ; the ratio of (a + b + c + k) : d is from 5 : 1 to 500 : 1, in which the monomer units may be in random order, a, b, c, d, e, f, g, h may be integer or zero; the ratio of k : (a + b + c + d) is from 1:99 to 30:70, preferably from 2:98 to 20:80, more preferably from 5:95 to 10:90;

R ¹ -R ⁶ are defined as in formula I;

R ¹¹ and R ^11* are independently selected from hydrogen or C _λ - C ₄ alkyl;

R ¹² is independently selected from C ₅ to C ₂₄ alkyl or alkenyl, aryl cycloalkyl, hydroxyalkyl or alkoxyalkyl; and

B ¹ , B ² , B ³ , B ⁴ are organic or inorganic anions; the anions represented by B ¹ , B ² , B ³ , B ⁴ are exemplified by the halide ions, sulphate, sulphonate, phosphate, hydroxide, borate, cyanide, carbonate, bicarbonate, thiocyanate, sulphide, cyanate, acetate and the other common inorganic and organic ions. Preferred anions are chloride and methosulphate.

A fourth group of preferred deflocculating polymers of the present invention, having hydrophilic backbone and one or more hydrophobic side-chains and being especially suitable for fabric softening compositions comprising an aqueous base and one or more fabric-softening materials, is of the formula (IV) :

wherein: z is 1; n is at least 1; k is at least 1; the ratio of (j + k) : z is from 5 : 1 to 500 : 1; the ratio of k : (j + z) is from 1 : 99 to 30 : 70, preferably from 2 : 98 to 20 : 80, more preferably from 5 :

95 to 10 : 90; in which the monomer units may be in random order;

R _> l_-*Ro6° are defined as in formula I;

R >13 ^J represents -CH ₂ ~, -C ₂ H ₄ -, ^_ C ₃ H ₆ or is absent;

R _> 14 represents from 1 to 50 independently selected alkyleneoxy groups, preferably ethylene oxide groups, or is

absent .

R ¹⁵ represents -H or -OH.

A fifth group of preferred deflocculating polymers of the present invention, having nonionic monomers and ionic monomers, is of the formula (V) :

H. CH-,—C* ■CH- CH-

wherein: the monomer units may be in random order; z is 1; k is at least 1; n is at least 1 (and can be determined from the molecular weight) ; the ratio of (k + x) : z is from 1 : 1 to 2,000 : 1, preferably from 4 : 1 to 1,000 : 1 more preferably from

6 : 1 to 250 : 1; the ratio of k : (x + z) is from 1:99 to 30:70, preferably from 2:98 to 20:80, more preferably from 5:95 to 10:90;

R ¹ represents -C ₃ H ₆ -N ⁺ -(CH ₃ ) ₃ (Cl ^~ * , -C ₂ H ₄ -0S0 ₃ ^~( Na ⁺ ) , -S0 ₃ ^~( Na ⁺ ), -C ₂ H ₄ N ⁺ (CH ₃ ) ₃ Cl ^" \' -C ₂ H ₄ N ⁺ (C ₂ H ₆ ) ₂ Cl ^" , -CH ₂ N ⁺ (CH ₃ ) ₃ Cl ^" \' -CH ₂ N ⁺ (C ₂ H ₆ ) ₂ Cl ^" or benzyl-S0 ₃ ^~ (Na ⁺ ) ;

^l represents -C0-0-, -0-, -0-C0-, -CH ₂ -, -C0-NH-, or is

absent ;

R ³ and R ⁴ represent hydrogen or C _λ _ ₄ alkyl,

R ^a is CH ₂ , C ₂ H ₄ , C ₃ H ₆ or is absent;

R ^D represents form 1 to 50 independently selected alkylene oxide groups, preferably ethylene oxide groups or is absent;

R ^c represents -OH or -H;

and wherein if R ² , R ^a and R ^b are absent, then R ^c is not -H.

A sixth group of preferred deflocculating polymers of the present invention, being a block copolymer having alternating hydrophobic and hydrophilic groups is represented by the formulae (VI) :

wherein: the monomer units may be in random order; x is from 4 to 1,000, preferably from 6 to 250; k is at least 1; the ratio of k : x is from 1:99 to 30:70, preferably from

2:98 to 20:80, more preferably from 5:95 to 10:90;

R ¹ represents a C ₂ _ ₂₄ alk(en)yl group, preferably C ₃ _ ₂₄ alk(en)yl, more preferably C ₅ _ ₂₄ alk(en)yl group, most preferably a C ₆ _ ₂₄ alk(en)yl group, and/or from 4 to 50 propylene oxide or butylene oxide;

R ² represents -CO-;

R ³ represents -CO-O- or -O-

The general formulae I-VI are to be construed as including those mixed copolymer forms wherein, within a particular polymer molcule where n is 2 or greater, R ¹ -R ¹⁵ differ beetween individual monomer units therein.

Molecular weight

Polymers for use in compositions may have a molecular weight between 500 and 1,000,000. The molecular weight is measured by GPC using polyethyleneglycol standards. For the purposes of this definition, the molecular weight of the standards are measured by the absolute intrinsic viscosity method described by Noda, Tsoge and Nagasawa in Journal of Physical Chemistry, Volume 74, (1970), page 710-719. Polymers according to the invention, preferably have molecular weights of from 750-100,000, more preferably of from 1,000 to 30,000, most preferably of from 2,000 to 10,000.

Ketone group incorporation in the polymer The polymers for use in detergent compositions of the invention may be prepared by using conventional polymerization procedures, such as radical polymerization, cationic-anionic polymerization or a combination thereof.

The ketone-group can be incorporated in the deflocculating polymer as described in our co-pending application GB

9207795.7 filed on 9 April 1992. The ketone groups can for example be derived from a compound of the formula (X) :

wherein each of R4 and R5, which may be the same or different, represents a group capable of stabilising a free radical.

Preferably, one of R4 and R5 represents an aryl or cyano group, and the other represents an aryl, alkyl or cyano group. Preferably at least one of R4 and R5 is a phenyl group, and the compound in which R4 and R5 both represent phenyl groups is especially preferred. This compound is 2,2-diphenyl-4-methylene-l,3-dioxolane.

On heating and in the presence of a free radical initiator, the ring of the monomer of the formula (X) opens. This product can be utilised to introduce a ketone functionality into the polymer by reaction with co-monomers.

Biodegradability tests

Suitable tests for determining biodegradability are given in the OECD Guidelines. Other suitable tests involve the detection of released C0 ₂ upon decomposition of the polymer material, in these tests sometimes ¹⁴ C labelled polymers may be used.

Preferably polymers for use in compositions of the invention satisfy one or more of the following tests:

(a) Modified SCAS test as described in OECD Guideline 302a. This test measures removal of test material by dissolved organic carbon analysis. It is believed that a 80 % removal is a reasonable indication of biodegradability or adsorption.

(b) Modified Sturm test as described in OECD Guideline 301b. This test measures C0 ₂ production from the test material under standard conditions, the polymer being enclosed in a sealed vessel inoculated with bacteria acclimatised to the test polymer in a sewage enrichment study. Values of 25 to 35% conversion to C0 ₂ in the modified Sturm test and similar tests have frequently been reported for polymers, but that can be attributed to the presence of monomers and low- molecular-weight oligo ers. Values of 50% and above in this type of test are an indication of superior biodegradability. A 60 % conversion to C0 ₂ in the

Sturm test is an indication of ready biodegradability.

Although it is preferred that polymers for use in composition of the invention satisfy both tests, applicants have found that polymers satisfying one biodegradability tests is suitable for use in the present invention.

Product forms

Deflocculating polymers according to the invention can for example be used in liquid detergent composisitons, general purpose cleaners, liquid abrasive cleaners, liquid bleach compositions as disclosed in WO/91/09108 and also in granular detergent compositions as disclosed in WO/91/09932.

Deflocculating polymers can in particular be used in liquid detergent compositions that comprise a dispersion of

lamellar droplets in an aqueous continuous phase.

Lamellar droplets are a particular class of surfactant structures which, inter alia, are already known from a variety of references, e.g. H.A.Barnes, \'Detergents\', Ch.2. in K.Walters (Ed), \'Rheometry: Industrial Applications\', J. Wiley & Sons, Letchworth 1980.

Such lamellar dispersions are used to endow properties such as consumer-preferred flow behaviour and/or turbid appearance. Many are also capable of suspending particulate solids such as detergency builders or abrasive particles. Examples of such structured liquids without suspended solids are given in US patent 4 244 840, whilst examples where solid particles are suspended are disclosed in

EP-A-160 342; EP-A-38 101; EP-A-140 452 and also in the aforementioned US 4 244 840. Others are disclosed in EP-A- 151 884, where the lamellar droplet are called \'spherulites\' .

The presence of lamellar droplets in a liquid detergent product may be detected by means known to those skilled in the art, for example optical techniques, various rheometrical measurements, X-ray or neutron diffraction, and electron microscopy.

The droplets consist of an onion-like configuration of concentric bi-layers of surfactant molecules, between which is trapped water or electrolyte solution (aqueous phase) . Systems in which such droplets are close-packed provide a very desirable combination of physical stability and solid- suspending properties with useful flow properties.

The viscosity and stability of the liquid product depend on the volume fraction of the liquid which is occupied by the droplets. Generally speaking, when the volume fraction is around 0.6, the droplets are just touching (space-filling).

This allows reasonable stability with an acceptable viscosity and endows useful solid-suspending properties.

Problems in formulating liquid detergent compositions of high lamellar phase volume are possible instability and/or high viscosity of the product, as described in our patent application EP 346 995. Compositions of the invention preferably have a viscosity of less than 2,500 mPas at 21 s-1, more preferred less than 1,500 mPas, most preferred less than 1,000 mPas, especially preferred between 100 and 750 mPas at 21 s-1.

Liquid compositions according to the invention are physically stable and have a relatively low viscosity, i.e. a corresponding composition minus the deflocculating polymer is less stable and/or has a higher viscosity. In the context of the present invention, physical stability for these systems can be defined in terms of the maximum separation compatible with most manufacturing and retail requirements. That is, the \'stable\' compositions will yield no more than 10 %, preferably no more than 5 %, most preferred no more than 2% by volume phase separation as evidenced by appearance of 2 or more separate phases when stored at 25°C for 21 days from the time of preparation.

Preferably, liquid compositions of the invention comprising polymers according to formulae I, II, 2V and VI have a pH of between 6 and 14, more preferred from 6.5 to 13, especially preferred from 7 to 12. Preferably, liquid compositions of the invention comprising polymers according to formulae III and IV have a pH of less than 6.0, more preferred less than 5.0, especially from 1.5 to 4.5, most preferred from 2.0 to 4.0. Liquid compositions of the invention comprising polymers according to formulae I and II may also have low pH, i.e. more preferred less than 5.0, especially from 1.5 to 4.5, most preferred from 2.0 to 4.0.

The amount of the deflocculating polymer to be used is dependent on the product form in which it is used, as well as on the function in the product. In general the deflocculating polymer will be used at levels of from 0.01 to 5 % by weight of the composition, more preferably from 0.1 to 3.0, especially preferred from 0.25 to 2.0 %.

Other ingredients

Compositions of the invention also comprise detergent active materials, preferably at a level of from 1 to 70% by weight of the composition, more preferred a level of 5 to 40 % by weight, most preferred from 10 to 35 % by weight.

In the case of blends of surfactants, the precise proportions of each component which will result in lamellar structures will depend on the type(s) and amount(s) of the electrolytes, as is the case with conventional structured liquids.

In the widest definition the detergent-active material in general, may comprise one or more surfactants, and may be selected from anionic, cationic, nonionic, zwitterionic and amphoteric species, and (provided mutually compatible) mixtures thereof. For example, they may be chosen from any of the classes, sub-classes and specific materials described in \'Surface Active Agents\' Vol.I, by Schwartz & Perry, Interscience 1949 and \'Surface Active Agents\' Vol.II by Schwartz, Perry & Berch (Interscience 1958), in the current edition of "McCutcheon\'s Emulsifiers & Detergents" published by the McCutcheon division of Manufacturing

Confectioners Company or in \'Tensid-Taschenbuch\' , H.Stache, 2nd Edn., Carl Hanser Verlag, Mϋnchen & Wien, 1981.

Suitable nonionic surfactants include, in particular, the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example aliphatic alcohols, acids, amides or alkyl phenols with alkylene

oxides, especially ethylene oxide, either alone or with propylene oxide. Specific nonionic detergent compounds are alkyl (C ₆ -C ₁₈ ) primary or secondary linear or branched alcohols with ethylene oxide, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenedia ine. Other so-called nonionic detergent compounds include long chain tertiary amine oxides, long-chain tertiary phosphine oxides and dialkyl sulphoxides.

Preferably the level of nonionic surfactant materials is from 1 to 40 % by weight of the composition, more preferred from 2 to 20%.

Compositions of the present invention may contain synthetic anionic surfactant ingredients, which are preferably present in combination with the above mentioned nonionic materials. Suitable anionic surfactants are usually water- soluble alkali metal salts of organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher acyl radicals. Examples of suitable synthetic anionic detergent compounds are sodium and potassium alkyl sulphates, especially those obtained by sulphating higher (C ₈ -C ₁₈ ) alcohols produced, for example, from tallow or coconut oil, sodium and potassium alkyl (C ₉ -C ₂₀ ) benzene sulphonates, particularly sodium linear secondary alkyl (C ₁₀ -C ₁₅ ) benzene sulphonates; sodium alkyl glycerol ether sulphates, especially those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum; sodium coconut oil fatty monoglyceride sulphates and sulphonates; sodium and potassium salts of sulphuric acid esters of higher (C ₈ -C ₁₈ ) fatty alcohol-alkylene oxide, particularly ethylene oxide, reaction products; the reaction products of fatty acids such as coconut fatty acids esterified with isethionic acid and neutralized with

sodium hydroxide; sodium and potassium salts of fatty acid amides of methyl taurine; alkane monosulphonates such as those derived by reacting alpha-olefins (C ₈ - ₂₀ ) with sodium bisulphite and those derived from reacting paraffins with S0 ₂ and Cl ₂ and then hydrolyzing with a base to produce a random sulphonate; and olefin sulphonates, which term is used to describe the material made by reacting olefins, particularly C ₁₀ -C ₂₀ alpha-olefins, with S0 ₃ and then neutralizing and hydrolyzing the reaction product. The preferred anionic detergent compounds are sodium (C- _L - _j .-C- _Lg ) alkyl benzene sulphonates and sodium (C ₁₆ -C ₁₈ ) alkyl sulphates.

Generally the level of the above mentioned non-soap anionic surfactant materials is from 1-40 % by weight of the composition, more preferred from 2 to 25 %. It is also possible, and sometimes preferred, to include an alkali metal soap of a mono- or di-carboxylic acid, especially a soap of an acid having from 12 to 18 carbon atoms, for example oleic acid, ricinoleic acid, alk(en)yl succinate for example dodecyl succinate, and fatty acids derived from castor oil, rapeseed oil, groundnut oil,coconut oil, palmkernel oil or mixtures thereof. The sodium or potassium soaps of these acids can be used. Preferably the level of soap in compositions of the invention is from 1-35% by weight of the composition, more preferred from 5-25%. Also possible is the use of salting out resistant active materials such as for example described in EP 328 177, especially the use of alkyl poly glycoside surfactants such as for example disclosed in EP 70 074. Also alkyl mono glucosides may be used.

The compositions optionally also contain electrolyte in an amount sufficient to bring about lamellar structuring of the detergent-active material. Preferably the compositions contain from 1% to 60%, especially from 10 to 45% of a salting-out electrolyte. Salting-out electrolyte has the

meaning ascribed to in specification EP-A-79 646. Optionally, some salting-in electrolyte (as defined in the latter specification) may also be included.

In any event, it is preferred that compositions according to the present invention include detergency builder material, some or all of which may be electrolyte. In this context it should be noted that some detergent active materials such as for example soaps, also have builder properties.

Examples of phosphorous containing inorganic detergency builders include the water-soluble salts, especially alkali metalpyrophosphates, orthophosphates, polyphosphates and phosphonates. Specific examples of inorganic phosphate builders include sodium and potassium tripolyphosphates, phosphates and hexametaphosphates. Phosphonate sequestrant builders may also be used. Sometimes it is however preferred to minimise the amount of phosphate builders.

Examples of non-phosphorus-containing inorganic detergency builders, when present, include water-soluble alkali metal carbonates, bicarbonates, silicates and crystalline and amorphous aluminosilicates. Specific examples include sodium carbonate (with or without calcite seeds) , potassium carbonate, sodium and potassium bicarbonates, silicates and zeolites.

In the context of inorganic builders, we prefer to include electrolytes which promote the solubility of other electrolytes, for example use of potassium salts to promote the solubility of sodium salts. Thereby, the amount of dissolved electrolyte can be increased considerably (crystal dissolution) as described in UK patent specification GB 1 302 543.

Examples of organic detergency builders, when present,

include the alkaline metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates, polyacetyl carboxylates and polyhydroxysulphonates. Specific examples include sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylenediaminetetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid, melitic acid, benzene polycarboxylic acids, CMOS, tartrate mono succinate, tartrate di succinate and citric acid. Citric acids or salts thereof are preferred builder materials for use in compositions of the invention.

In the context of organic builders, it is also desirable to incorporate polymers which are only partly dissolved, in the aqueous continuous phase as described in EP 301 882.

This allows a viscosity reduction (due to the polymer which is dissolved) whilst incorporating a sufficiently high amount to achieve a secondary benefit, especially building, because the part which is not dissolved does not bring about the instability that would occur if substantially all were dissolved. Typical amounts are from 0.5 to 4.5% by weight.

It is further possible to include in the compositions of the present invention, alternatively, or in addition to the partly dissolved polymer, yet another polymer which is substantially totally soluble in the aqueous phase and has an electrolyte resistance of more than 5 grams sodium nitrilotriacetate in 100ml of a 5% by weight aqueous solution of the polymer, said second polymer also having a vapour pressure in 20% aqueous solution, equal to or less than the vapour pressure of a reference 2% by weight or greater aqueous solution of polyethylene glycol having an average molecular weight of 6000; said second polymer having a molecular weight of at least 1000. Use of such polymers is generally described in our EP 301,883. Typical levels are from 0.5 to 4.5% by weight.

Preferably the level of non-soap builder material is from 5-40 % by weight of the composition, more preferred from 5 to 25 % by weight of the composition.

Optional ingredients

Apart from the ingredients already mentioned, a number of optional ingredients may also be present, for example lather boosters such as alkanolamides, particularly the monoethanolamides derived from palm kernel fatty acids and coconut fatty acids, lather depressants, oxygen-releasing bleaching agents such as sodium perborate and sodium percarbonate, peracid bleach precursors, chlorine-releasing bleaching agents such as trichloroisocyanuric acid, inorganic salts such as sodium sulphate, and, usually present in very minor amounts, fluorescent agents, perfumes, enzymes such as proteases, amylases and lipases (including Lipolase (Trade Mark) ex Novo) , enzyme stabilizers, anti-redeposition agents, germicides and colorants.

Obviously in selecting the materials other than the polymer for use in compositions of the invention, also biodegradable materials are preferred for environmental reasons.

Preparation of liguid detergent composition

Liquid compositions of the invention may be prepared by any conventional method for the preparation of liquid detergent compositions. A preferred method involves the dispersing of the electrolyte ingredient (if present) together with the minor ingredients except for the temperature sensitive ingredients -if any- in water of elevated temperature, followed by the addition of the builder material- if any-, the detergent active material (possibly as a premix) under stirring and thereafter cooling the mixture and adding any temperature sensitive minor ingredients such as enzymes

perfumes etc. The deflocculating polymer may for example be added after the electrolyte ingredient or as the final ingredient. Preferably the deflocculating polymers are added prior to the formation of the lamellar structure.

In use the detergent compositions of the invention will be diluted with wash water to form a wash liquor for instance for use in a washing machine. The concentration of liquid detergent composition in the wash liquor is preferably from 0.1 to 10 %, more preferred from 0.1 to 3% by weight.

The invention will now be illustrated by way of the following non-limiting Examples.

EXAMPLE I

Synthesis of a deflocculating polymer :

¹ * ¹ 2,2-diphenyl-4-methylene-l,3-dioxolane

Procedure:

The water and isopropanol (IPA) was charged into a reaction vessel mounted in a heating bath thermostated at 100°C and degassed with oxygen free nitrogen. The DMD was dissolved in the acrylic acid-lauryl methacrylate by warming. The mixed monomer solution was then added dropwise over 3 hours to the stirred water/IPA solution. At the same time the persulphate initiator solution was fed in from another dropping funnel over a 4 hour period. After the addition was completed, the heating and stirring was continued for another 18 hours. This gave a sticky solid and an emulsion. 92 % of the theoretical amount of sodium hydroxide (in 30ml water) was added to achieve neutrality (pH 7) . The IPA was removed by distillation using a rotary evaporator and the concentrate poured into acetone to precipitate the polymer and remove benzophenone. The polymer was separated, dissolved in water and precipitated again into acetone and the process repeated. Finally, the polymer was redissolved in water, filtered through glass fibre to remove the last traces of benzophenone then freeze-dried. Polymer yield 29.4g (94.5%). The polymer was characterised by IH and 13C NMR, FT-IR and GPC. Molecular weights by aqueous GPC: Mn = 9,800 MW = 32,200 D= 3.3.

EXAMPLE 2

The following compositions were prepared by adding the citrate together with sufficient NaOH, to neutralise the active materials and to bring the pH of the final composition to 7, to water at a temperature of 30°C under stirring, followed by addition of the deflocculating polymer and a premix of the Synperonic and Dobs (in acid form) .

Basic composition 1: Ingredients (wt)

Na Dobs 24.5

Synperonic A7 9.9

Na-citrate 2aq 16.4

Water 49.2

Deflocculation polymer weights additional to basic formulation

Polymer A is of the basic structure of formula I, wherein x = 24, k = 1, y = 0, R ¹ is -CO-0-, R ² and R ³ are absent, R ⁴ is -C ₁₂ H ₂₅ , R ⁵ is -H, R ⁶ is -CH ₃ , A ¹ is Na and B ¹ is -H. The molecular weight is 32,200.

The following results were obtained:

No. Basic Polymer % Stability Viscosity Composition m Pa.s at 21s ^"1

1 1 - - Unstable 1750 - 2560 ^* > 2 1 A 1.0 Stable 60

*• ^■ Unreliable results due to rapid phase separation.

The polymer is also believe to have an acceptable biodegradability.