Radiation-curable copolymers of monoethylenic monomers

Abstract

Radiation-curable linear addition polymers or copolymers are disclosed having a weight average molecular weight of from about 1,500 to about 15,000 of polymerized monoethylenically unsaturated monomers, which may include up to 25% by weight of an hydroxy-functional monomer, and which carries an hydroxyl group at most of its ends, reacted with a monoethylenically unsaturated monomer carrying a single functional group reactive with the hydroxyl group, so that the polymer carries monoethylenically unsaturated groups bonded to an average of from 1.6 to 5 of the hydroxyl groups per polymer molecule. The preferred radiation-curable polymers are liquid to slowly flowable at room temperature in the absence of organic solvent, and the monoethylenically unsaturated groups are preferably acrylate groups to enable an ultraviolet cure. The terminal hydroxyl groups and the unusually low molecular weight are provided using a bis hydroxyorganic xanthogen disulfide as a chain terminating catalyst when the polymers are formed, and a small proportion of additional hydroxy functionality can be incorporated into the polymers using a hydroxyl functional monomer.

Dependencies are inferred from the claim text.