COMPOSITE PARTICLES, METHOD FOR PRODUCING COMPOSITE PARTICLES, AND USE THEREOF

1 . A method for producing composite particles containing polymer particles and silica particles that adhere to the polymer particles, comprising a polymerization step of subjecting a polymerizable monomer to aqueous suspension polymerization in a presence of silica particles and a water-soluble cellulose compound adsorbing onto surfaces of the silica particles, so as to obtain the composite particles.

2 . The method for producing composite particles according to claim 1 ,

wherein at least one of hydroxypropyl cellulose and hydroxypropyl methylcellulose is used as the water-soluble cellulose compound.

3 . The method for producing composite particles according to claim 1 , further comprising, before the polymerization step, an adsorption step of treating the silica particles with the water-soluble cellulose compound so as to adsorb the water-soluble cellulose compound onto the surfaces of the silica particles.

4 . The method for producing composite particles according to claim 3 ,

wherein, in the adsorption step, the water-soluble cellulose compound is adsorbed onto the surfaces of the silica particles by making the silica particles coexist with the water-soluble cellulose compound under a temperature condition where the water-soluble cellulose compound has a temperature of (T-15)° C. or more (where T represents a lower critical solution temperature (° C.) or a cloud point (° C.) of the water-soluble cellulose compound).

5 . The method for producing composite particles according to claim 1 ,

wherein an amount of the silica particles is from 0.022 to 0.15 g/m 2 per unit surface area of the composite particles.

6 . Composite particles obtainable by the method for producing composite particles according to claim 1 ,

wherein at least part of surfaces of the polymer particles is covered by a layer of the silica particles.

7 . Composite particles comprising polymer particles, silica particles that adhere to surfaces of the polymer particles, and water-soluble cellulose compound.

8 . The composite particles according to claim 7 ,

wherein an adhesion amount of the silica particles to the surfaces of the polymer particles is from 0.010 to 0.10 g/m 2 per unit surface area of the composite particles.

9 . The composite particles according to claim 7 ,

wherein at least part of the surfaces of the polymer particles is covered by a layer of the silica particles.

10 . An external preparation comprising the composite particles according to claim 7 .

11 . A coating agent comprising the composite particles according to claim 7 .

12 . An optical film obtainable by applying the coating agent according to claim 11 onto a base material.

13 . A resin composition comprising: the composite particles according to claim 7 ; and a base resin.

14 . A molded product obtainable by molding the resin composition according to claim 13 .