Patent ID: 6967227

Claim:
A method for producing carboxyester-modified vinylic polymeric compositions which comprises reacting in a free-radical addition polymerization reaction: (A) about 40.0% to about 80.0% by total weight of the reactants of a monomer mixture comprising: (1) about 15.0% to about 45.0% by total weight of the monomer 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 monomer 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 monomer mixture of chain transfer agent; and (B) about 20.0% to about 60.0% by total weight of the reactants of a mixture comprising: (1) about 40.0% to 100.0% of at least one carboxyester formed by the condensation of at least one hydroxyl-substituted fatty acid and at least one carboxylic anhydride; and (2) up to about 60.0% of at least one rosin; at a temperature in the range of about 135° C. to about 240° C. to produce a carboxyester-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 300.