To obtain the subject emulsion having excellent storage stability, providing a coated film having excellent hardness and flexibility, especially water resistance, useful for a coating material, etc., by polymerizing a radical- polymerizable monomer and an a colloidal metal oxide under specific conditions.
A mixture comprising (A) a radical-polymerizable monomer, (B) an oil-soluble radical polymerization initiator and (C) a colloidal metal oxide (preferably colloidal silica) is emulsified and dispersed in an aqueous medium in the presence of (D) a surfactant to produce an emulsified dispersion and the dispersion is dripped into a heated aqueous medium to polymerize the component A. Preferably the component A is a monomer mixture composed of 0.5-50 wt.% of an alkoxysilyl group-containing radical-polymerizable monomer and 99.5-50 wt.% of a radical-polymerizable monomer copolymerizable with the monomer.
TSUDA TAKASHI
YAMAMURA TAKENAO
