PURPOSE: To obtain an abrasive which has improved impact resistance and can effectively remove resin flash without impairing the appearance of a molded article, etc., by the suspension polymerization of an unsaturated polyester resin in an aqueous medium in the presence of a rubbery polymer.
CONSTITUTION: An unsaturated dibasic acid and a glycol compound are esterified to give an unsaturated ester, which is then dissolved in a polymerizable vinyl monomer. A rubbery polymer is sufficiently dispersed in this solution, and the dispersion is made to undergo suspension polymerization in an aqueous medium in the presence of a polymerization initiator to five a slurry containing spherical polyester resin. This slurry is filtered to give a synthetic resin abrasive. The abrasive thus obtained can effectively remove resin flash from a molded article to give molded material almost free from surface roughening.
WATABE KATSUSHI
OISHI IWAO
