To obtain composite particles composed of a polymer and spherical particles having a controlled particle diameter and contained within the polymer dissolving a substance which forms spherical particles in a monomer containing a crosslinking agent and subjecting the entire mixture to an aqueous suspension polymerization.
This composite particle is composed of a crosslinked polymer 1 and at least one kind of spherical particles 2 contained within the polymer 1. The monomer used to form the crosslinked polymer comprises a monofunctional vinyl compound having one vinyl group in the molecule and a crosslinking agent having at least two vinyl groups in the molecule. It is desirable that the monofunctional vinyl compound contains at least 20wt.% styrene or at least 5wt.% trifluoroethyl methacrylate. The substance which forms spherical particles is desirably a silicone oil. The composite particles are produced by dissolving 1-30 pts.wt. substance which forms spherical particles in 100 pts.wt. monomer containing a crosslinking agent and subjecting the entire mixture to aqueous suspension polymerization.
TOKUI MASAKI
SASAKI SHIGEAKI
