PROCESS FOR MAKING VINYL PYRROLIDONE/VINYL ACETATE COPOLYMERS WITHIN A SHORT PRODUCTION CYCLE

摘要

Vinyl pyrrolidone/vinyl acetate copolymers having a very low residual vinyl pyrrolidone monomer level, i.e. < 100 ppm, preferably only 50 ppm, are made within an advantageously short production cycle, by post-treating an aqueous solution of the copolymer at an elevated temperature of about 120-150 °C, preferably about 130 °C, under pressure, in the presence of a high temperature initiator, for a period of about 1-4 hours, preferably 2 hours.