Patent ID: 8419976

Claim:
A polyelectrolyte complex composition capable of viscosifying or thickening an aqueous high salt-containing system, which comprises a mixture of at least one anionic polymer and at least one cationic polymer in an inorganic salt-containing aqueous medium, wherein the anionic polymer has a charge density of greater than 50% of the anionic monomer used to make the anionic polymer or >2.4 meq/g active copolymer, and the cationic polymer has a charge density of greater than 35% of the cationic monomer used to make the cationic polymer or >1.6 meq/g active polymer and the anionic polymer is a weak polyelectrolyte and the cationic polymer is a strong polyelectrolyte or the anionic polymer is a strong polyelectrolyte and the cationic polymer is a weak polyelectrolyte.