Patent ID: 6849681

Claim:
A method for producing carboxylic acid-modified vinylic polymeric compositions which comprises reacting in a free-radical addition polymerization reaction: (A) About 40% to about 80% by total weight of the reactants of a monomer mixture comprising: (1) about 15.0% to about 45.0% by total weight of the mixture of a member selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic anhydride, itaconic acid, and combinations thereof, (2) about 55.0% to about 85.0% by total weight of the mixture of a member selected from the group consisting of non-carboxylic acid-containing vinylic monomers and combinations thereof, (3) a catalytic amount of polymerization initiator, and (4) up to about 4.0% by total weight of the mixture of chain transfer agent, and (B) about 20% to about 60% by total weight of the reactants of a carboxylic acid mixture comprising: (1) about 20.0% to about 100.0% by total weight of the mixture of a member selected from the group consisting of dimer acids, trimer acids, functional equivalents of dimer acid, functional equivalents of trimer acid, dimerized rosins, and combinations thereof; (2) up to about 80.0% by total weight of the mixture of a member selected from the group consisting of rosins, unsaturated fatty acids, and combinations thereof; and (3) up to about 0.1% by total weight of the mixture of bleaching agent, at a temperature in the range of about 135° C. to about 220° C. to produce a carboxylic acid-modified vinylic polymeric composition having a weight average molecular weight in the range of about 4,000 to about 20,000 and an acid number in the range of about 160 to about 260.