Fine resin particle and application thereof

Abstract

The invention has a problem of providing a fine resin particle that is useful as an anti-blocking agent or other agents, has sufficient resistance to the thermal load applied when compounded with resins, shows sufficiently lowered residual amount of unreacted monomers in the fine resin particle, and, furthermore, has a color tone that does not affect optical properties even when used in optical members, to which very high optical characteristics (colorless transparency) are required, or other members. As means for solving this problem, the present invention provides a fine resin particle including a copolymer of at least one monofunctional vinylic monomer (A) unit with a cyclic structure in a molecular structure, at least one monofunctional alkyl (meth)acrylate-based monomer (B) unit, at least one multifunctional (meth)acrylate-based monomer (C) unit, and at least one multifunctional thiol (D) unit, wherein a polymer consisting only of the monofunctional alkyl (meth)acrylate-based monomer (B) has a glass transition temperature of 50° C. or lower.