Acrylamide copolymer thickener for aqueous systems

Claim 2

A nonionic or anionic water-soluble addition copolymer of monomers comprising, by weight, (A) at least 50% of acrylamide; (B) 0.01 to 50% of a compound having the formula ##STR5## wherein R 1 is ##STR6## R 2 is H or ##STR7## R 3 and R 5 are H or methyl, independently, R 4 and R 6 are hydrocarbyl having 6 or more carbons, independently, and m and n are zero or a positive integer, independently; and (C) 0 to 49.99% one or more other olefinically unsaturated monomers; the copolymer having a weight average molecular weight greater than 30,000.

Claim 3

The copolymer of claim 1 wherein R 4 is C 6 to C 36 alkyl.

Claim 4

The copolymer of claim 2 wherein R 2 is H.

Claim 5

The copolymer of claim 3 wherein the monomers comprise 0.05 to 40% (B) and the average molecular weight is about 50,000 to about 1 million.

Claim 6

The copolymer of claim 4 wherein R 4 is C 8 to C 18 alkyl.

Claim 7

The copolymer of claim 5 wherein at least 50%, by weight, of the other olefinically unsaturated monomers are water-soluble monomers.

Claim 8

The copolymer of claim 6 wherein R 4 is R 7 R 8 CH-- wherein R 7 and R 8 are alkyl, and n is zero.

Claim 9

The copolymer of claim 1 wherein R 2 is H, n is 1 to 50, and the monomers comprise 0.2 to 20% (B).

Claim 10

The copolymer of claim 8 wherein R 4 is C 6 to C 36 alkyl or aralkyl and wherein the averge molecular weight is from 50,000 to 1,000,000.

Claim 11

The copolymer of claim 4 or claim 8 prepared in the presence of a mercaptan chain transfer agent having 8 or more carbon atoms.

Claim 12

The copolymer of claim 6 or claim 9 prepared in the presence of an alkyl mercaptan chain transfer agent having 12 to 22 carbon atoms.

Claim 13

The copolymer of claim 4 or claim 8 wherein up to 30% by weight of the monomers are water-soluble other olefinically unsaturated monomers.

Claim 14

The copolymer of claim 6 or claim 9 wherein up to 30% by weight of the monomers are other olefinically unsaturated monomers selected from N-vinylpyrrolidone, hydroxyethyl methacrylate, hydroxyethyl acrylate, acrylic acid or methacrylic acid.

Claim 15

The copolymer of claim 7 the monomers consisting essentially of (A) acrylamide; (B) 0.05 to 40% of a compound having the formula ##STR8## (C) 0 to 30% N-vinylpyrrolidone, hydroxyethyl acrylate, hydroxyethyl methacrylate, methacrylic acid, acrylic acid, or a mixture of these; having a weight average molecular weight between 100,000 and 700,000.

Claim 16

The copolymer of claim 7 the monomers consisting essentially of (A) acrylamide and (B) Y to Z% of a compound having the formula ##STR9## wherein Y and Z are: ______________________________________ Number of Effective Carbons in R.sub.4 Y Z ______________________________________ 6 to 9 2 40 over 9 to 12 0.5 30 over 12 to 15 0.4 20 over 15 to 18 0.2 10 over 18 0.05 8 ______________________________________

Claim 17

The copolymer of claim 14 wherein monomer (B) is 0.2 to 20% and (C) is 0 to 20%, by weight.

Claim 18

The copolymer of claim 15 wherein Y and Z are ______________________________________ Number of Effective Carbons in R.sub.4 Y Z ______________________________________ 6 to 9 4 20 over 9 to 12 1 15 over 12 to 15 0.5 10 over 15 to 18 0.4 8 over 18 0.2 5 ______________________________________