Patent ID: 9611416
Date: 2017-04-04
CPC Classifications: C04B,C08F,C09K,E21B

Claim:
1. A salt-tolerant, thermally-stable rheology modifier comprising a terpolymer of acrylamide, 2-acrylamido-2-methyl-propanesulfonic acid (AMPS) and a long-chain alkyl acrylate having a chain length for the alkyl group of from 12-25 wherein the long-chain alkyl acrylate is stearyl acrylate, wherein said terpolymer is made through a dispersion polymerization process and a saturated KCl or NaCl solution containing 1% by weight of the terpolymer has a Brookfield viscosity of about 400 cps or more at 20° C.