Thickened aqueous surfactant compositions and their preparation

Claim 2

A thickened liquid composition comprising an acidic mixture of (a) water, (b) a thickening amount of alkali-soluble emulsion polymer thickener which has been at least partially neutralised in the presence or absence of, and subsequently acidified in the presence of, (c) anionic, nonionic and/or amphoteric surfactant in an amount of 5 to 40% by weight of (a), (b) and (c).

Claim 3

A composition according to Claim 1 having a pH from 1.2 to 7.0 preferably 1.2 to 6.5.

Claim 4

A composition according to Claim 1 having a pH from 3.5 to 7.0 preferably 5.0 to 6.5.

Claim 5

A composition according to any preceding claim containing 10% to 25% by weight of surfactant based on (a), (b) plus (c).

Claim 6

A composition according to any preceding claim wherein at least a part of the polymer thickener comprises emulsion copolymer obtained by aqueous emulsion copolymerization of (1) from 20% to 50% by weight of methacrylic acid and/or acrylic acid, (2) from 0.5% to 25% by weight of acrylic or methacrylic acid ester of CS-C30 alkyl, alkylaryl or polycyclic hydrocarbyl monoether of a polyethylene glycol having at least two oxyethylene units, this ester being defined by the following general formula: wherein R is H or CH 3 , n is 2 to 60, and may be an average number within that range, and R 0 is a hydrophobic alkyl, alkylaryl, or polycyclic alkyl group having 8 to 30 carbon atoms. (3) 40% to 60% by weight of (C I -C 4 )-alkyl, preferably ethyl, acrylate and/or methacrylate, and (4) optionally, a small amount of polyethylenically unsaturated monomer, the sum of the percentages of the copolymer components being 100%, and wherein the surfactant is compatible with the thickener(s).

Claim 7

A composition according to any preceding claim which also contains (d) from 0.5% to 5% by weight, based on (a), (b), (c) plus (d), as foam stabilizer, of dialkanol- amide in which the carboxyl group is substituted by C 12 -C 22 alkane, and wherein the liquid is free from turbidity.

Claim 8

A composition according to Claim 5 or 6 wherein in the thickener component 1) is methacrylic acid, R of component 2) is CH 3 -, n of component 2) is 20, R° of component 2) is mixed C 16 and C 18 alkyl, component 3) is ethyl acrylate, and component 4) is not present.

Claim 9

A process for preparing a thickened, acidic, aqueous liquid which comprises a) mixing, in aqueous medium, a thickening amount of ionic thickener with anionic nonionic and/or amphoteric surfactant, and b) before, during or after step (a), at least partially neutralizing the thickener; and subsequently c) acidifying the mixture; the amount of surfactant being 5 to 40% by weight of the total of surfactant,thickener and water.

Claim 10

A process for preparing a thickened, acidic, aqueous liquid which comprises a) mixing, in aqueous medium, a thickening amount of ionic thickener with anionic nonionic and/or amphoteric surfactant, and b) before, during or after step (a), at least partially neutralizing the thickener; and subsequently c) acidifying the mixture; the amount of surfactant being 5 to 40% by weight of the total of surfactant,thickener and water.

Claim 11

A process according to Claim 8 wherein the thickener is neutralized to a pH above 6.5, and the mixture is acidified to a p H below 6.5.

Claim 12

A process according to Claim 8 wherein the thickener is neutralized to a pH above 7.0, and the mixture is acidified to a pH below 7.0.

Claim 13

A process according to Claim 10 wherein the mixture is acidified to a pH of 1.2 to 7.0 preferably 3.5 to 7.0.

Claim 14

A process according to Claim 11 wherein the mixture is acidified to a pH of 5.0 to 6.5.

Claim 15

A process according to any of Claims 8 to 12 wherein at least a part of the thickener comprises thickener as defined in Claim 5 preferably as defined in Claim 7.

Claim 16

The use of partially neutralised alkali-soluble emulsion thickener as defined in Claim 1 in thickening an acidic aqueous mixture containing anionic, nonionic and/or amphoteric surfactant in an amount of 5 to 40 weight percent based on water, thickener and surfactant.