POLYMER PARTICLE, PROCESS FOR PRODUCTION THEREOF, AND EXTERNAL ADDITIVE FOR TONER

摘要

PROBLEM TO BE SOLVED: To provide a polymer particle which is used as an external additive for a toner capable of imparting sufficient fluidity to electrophotographic toner, and a process for production thereof. SOLUTION: The polymer particle is derived from a monomer mixture comprising a monofunctional vinyl monomer and urethane poly(meth)acrylate. The polymer particle has an average particle size of 0.05-1μm. The percentage of the monofunctional vinyl monomer and the urethane poly(meth)acrylate which may be used is 60-95 wt.% and 40-5 wt.%, respectively. The urethane poly(meth)acrylate comprises a urethane moiety having a molecular weight of 200-5,000 and two or more (meth)acrylate groups. COPYRIGHT: (C)2011,JPO&INPIT