Polymeric thickeners, processes for their preparation and uses thereof

A process for preparing a polymer useful as a thickening agent in aqueous polymeric latices comprising:

• (a) adding to a reaction zone a portion of the monomers and sufficient ethylene glycol or propylene glycol, with 0 to about 50% by weight of water based on the weight of glycol, to give a final product having a solids content less than about 50% by weight, said monomers consisting essentially of (i) about 10 to 98% by weight of at least one unsaturated carboxylic acid of 3 to 6 carbon atoms, (ii) about 1 to 50% by weight of at least one alkyl acrylate or alkyl methacrylate wherein the alkyl group is from 1 to 30 carbon atoms, and (iii) about 1 to 85% by weight of at least one ester of the formula ##STR14## wherein R and R.sub.2 are each hydrogen or methyl,
• x is a positive integer of 5 to 80,
• y is an integer of 0 to 20, and
• R.sub.1 is alkyl of 1 to 20 carbon atoms or alkyl phenyl where the alkyl group is from 1 to 20 carbon atoms;
• (b) heating the mixture of (a) to a temperature of at least about 50.degree. C.;
• (c) adding to the reaction zone a portion of a free-radical polymerization catalyst;
• and
• (d) feeding to the reaction zone the remainder of the monomers and catalyst;
• and
• (e) adding ammonia or a water-soluble organic amine after the polymerization is complete to adjust the pH to about 7 to 10.

A process for preparing a polymer useful as a thickening agent in aqueous polymeric latices comprising:

• (a) adding to a reaction zone about 10 to 50% by weight of the total of the monomers and sufficient ethylene glycol or propylene glycol, with 0 to about 30% by weight of water based on the weight of glycol, to give a final product having a solids content less than about 35% by weight, said monomers consisting essentially of (i) about 20 to 93% by weight of acrylic acid or methacrylic acid, (ii) about 2 to 30% by weight of an alkyl acrylate or alkyl methacrylate where the alkyl group is from 10 to 30 carbon atoms and (iii) about 5 to 50% by weight of an ester of the formula ##STR15## wherein R is hydrogen or methyl,
• x is a positive integer of 5 to 80, and
• R.sub.1 is alkyl of 1 to 15 carbon atoms or alkyl phenyl where the alkyl group is from 8 to 20 carbon atoms;
• (b) heating the mixture of (a) to a temperature in the range of about 70 to 110.degree. C.;
• (c) adding to the reaction zone about 2 to 50% by weight of the total of a free-radical polymerization catalyst;
• (d) continuously feeding to the reaction zone the remainder of the monomers and catalyst;
• and
• (e) adding ammonia or a water-soluble organic amine after the polymerization is complete to adjust the pH to about 7 to 10.

A process for preparing a polymer useful as a thickening agent in aqueous polymeric latices comprising:

• polymerizing monomers consisting essentially of (i) about 10 to 98% by weight of at least one unsaturated carboxylic acid of 3 to 6 carbon atoms, (ii) about 1 to 50% by weight of at least one alkyl acrylate or alkyl methacrylate wherein the alkyl group is from 1 to 30 carbon atoms, and (iii) about 1 to 85% by weight of at least one ester of the formula ##STR17## wherein R and R.sub.2 are each hydrogen or methyl,
• x is a positive integer of 5 to 80,
• y is an integer of 0 to 20, and
• R.sub.1 is alkyl of 1 to 20 carbon atoms or alkyl phenyl where the alkyl group is from 1 to 20 carbon atoms
• with a free-radical catalyst in sufficient glycol, with 0 to 50% by weight of water based on the weight of glycol, to give a final polymer solids concentration less than about 50% by weight.