Patent ID: 7252770

Claim:
A process for inhibiting calcium carbonate and calcium phosphate scale formation comprising adding to an aqueous system an effective amount of a polymer comprising a multifunctional polymer composition formed from a monomer mixture comprising: at least one dicarboxylic acid present in an amount of 15 to 40 mole percent, wherein the dicarboxylic acid monomer is 10 to 95 percent neutralized; at least one monocarboxylic acid present in an amount of 37 to 79 mole percent; at least one non-ionic monomer present in an amount of 1 to 8 mole percent, wherein the at least one non-ionic monomer is selected from the group consisting of C 1 -C 6 alkyl esters of (meth)acrylic acid and the alkali or alkaline earth metal or ammonium salts thereof, acrylamide and the C 1 -C 6 alkyl-substituted acrylamides, the N-alkyl substituted acrylamides, the N-alkanol-substituted acrylamides and combinations thereof; and at least one sulfonated or sulfated monomer present in an amount of 5 to 15 mole percent; wherein the polymer composition has a weight average molecular weight of from 2,500 to 6,000, and wherein the polymer composition inhibits calcium scale formation in an aqueous system having a Langelier Saturation Index greater than 2.0.