Acrylic-methylene succinic ester emulsion copolymers for thickening aqueous systems

Claim 1

A copolymer obtained by aqueous emulsion copolymerization of a monomer system comprising (A) about 1 to about 25 percent of at least one substituted monomer of the formula: ##STR11## in which x is an integer from 1 to 150, and y is an integer from 0 to 50, where R is alkoxy, alkylphenoxy, dialkylphenoxy, or alkyl carbonyloxy having 5 to 30 carbon atoms, or a sorbitan fatty ester of the formula ##STR12## where each of p, q, r and s is an integer and the sum of said integers is from 0 to 100, R 1 is H or --COR 2 and R 2 is alkyl, alkylphenyl, or dialkylphenyl having 5 to 30 carbon atoms; (B) about 5 to about 70 percent of a copolymerizable α, β-ethylenically unsaturated carboxylic acid monomer of the formula ##STR13## where R is H and R 1 is H, an alkyl group containing from 1 to 4 carbon atoms, or --CH 2 COOX; R is --COOX and R 1 is H, and X is H or an alkyl group containing from 1 to 4 carbon atoms, (C) about 10 to about 90 percent of at least one nonionic, copolymerizable α, β-ethylenically unsaturated monomer of the formula CH.sub.2 ═CYZ where Y is H and Z is CN, Cl, --COOR, --C 6 H 4 R, ##STR14## or --CH═CH 2; Y and Z are Cl, and Y is CH 3 and Z is CN, ##STR15## --CH═CH 2 , --C 6 H 4 R, or --COOR 1 , and R is H, Cl, Br or alkyl containing from 1 to 4 carbon atoms; R 1 is alkyl containing from 1 to 12 carbon atoms, or hydroxyalkyl containing from 2 to 8 carbon atoms, and R 2 is alkyl containing from 1 to 8 carbon atoms; and (D) up to 1 percent of a copolymerizable polyethylenically unsaturated cross-linking monomer, said percentages being by weight, based on the total weight of said monomers.