Solvent resistent acrylic resin and process for producing the same

Claim 1

A process for producing an acrylic resin having an intrinsic viscosity of about 0.028 to about 0.117 l/g and a weight-average molecular weight to number-average molecular weight ratio, measured by gel permeation chromatography, of about 2.3 to about 6.0, which process comprises polymerizing at a temperature range of from 40° C. to 170° C., using a polymerization initiator: A. about 50 to 100 wt. % of methyl methacrylate, and B. 0 to about 50 wt. % of at least one monomer selected from the group consisting of acrylic ester monomer and methacrylic ester monomer, said acrylic ester monomer comprising the reaction product of an alkyl alcohol having 1 to 8 carbon atoms and acrylic acid and said methacrylic ester comprising the reaction product of an alkyl alcohol having 2 to 12 carbon atoms and methacrylic acid; and adding, after initiation of polymerization, about 0.01 to about 5 wt. %, based on the weight of monomer, of a chain transfer agent comprising at least one compound selected from the group consisting of alkylmercaptans containing 4 to 18 carbon atoms; esters of thioglycolic acid and an alkyl alcohol having 1 to 12 carbon atoms; said chain transfer agent being added at a stage where the degree of conversion to the polymer is about 10 to about 60%.