PRODUCTION OF DISPERSION OF FINE HEAT-RESISTANT RESIN PARTICLE

PURPOSE:To obtain the titled dispersion, having improved solvent resistance, slipperiness, electrical characteristic, etc., and useful as an improver for heat resistance, moldability, etc., by polymerizing a polymerizable monomer containing a maleimide compound in an aqueous medium containing a water- miscible organic solvent. CONSTITUTION:A polymerizable monomer containing a maleimide compound expressed by the formula [R1 and R2 are H, halogen, 1-15C alkyl or (substituted) aryl; R3 is H, 1-15C alkyl, cycloalkyl or (substituted) aryl, e.g. N-ethylmaleimide, etc., is reacted in the presence of a polymerization initiator in an aqueous medium containing a water-miscible organic solvent, e.g. butyl cellosolve, etc., normally in an inert gas atmosphere to afford the aimed dispersion having normally 0.01-100mu resin particle diameter. The above-mentioned polymerizable monomer preferably contains a compound expressed by the formula as a principal component together with another monomer, e.g. methyl methacrylate, etc.