Patent ID: 8143327

Claim:
A method for producing a core-shell fine particle, the method comprising: preparing a monomer mixture containing 15 to 99% by mass of a crosslinkable monomer having a plurality of vinyl groups and 1 to 85% by mass of a monomer having an atom transfer radical polymerization initiating group; allowing the monomer mixture to be absorbed in organic monodispersed seed particles, which are slightly-crosslinked particles that are obtained by polymerization of a crosslinkable monomer having a plurality of vinyl groups added in an amount of not more than 2% by mass, dispersed in an aqueous medium; thereafter polymerizing the monomer mixture using a polymerization initiator to produce a core layer formed of monodispersed crosslinked fine particles containing atom transfer radical polymerization initiating groups and having an average particle size, measured by dynamic light scattering, of 50 to 900 nm and having a CV value, which represents the percentage of a particle size standard deviation to the average particle size, of 20% or less, wherein the monomer having the atom transfer radical polymerization initiating group is a compound represented by the following general formula (1): where X is an atom transfer radical polymerization initiating group represented by any one of the following general formulas (2) to (4): where: R 1 is an alkylene group having 1 to 4 carbon atoms or R 1 may not be present, R 2 and R 3 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 8 carbon atoms, an alkylaryl group having 6 to 8 carbon atoms, in which R 2 and R 3 in formula (3) are not both hydrogen atoms, and Y is a halogen atom; and performing graft polymerization of a monomer onto the resulting core layer to form a shell layer.