Resin composition for toner, method of preparing the same and toner

摘要

Disclosed herein is a resin composition for toner mainly composed of a graft polymer which is formed by (a) 90 to 99.9 percent by weight of a copolymer formed by copolymerizing a styrene monomer and (meth)acrylic ester to contain at least 50 percent by weight of the styrene monomer and (b) 0.1 to 10 percent by weight of an ethylene-vinyl acetate copolymer having a saponification value of 10 to 30 and a softening point of 70 DEG to 200 DEG C. This resin composition is prepared by graft-polymerizing the copolymer (a) and the ethylene-vinyl acetate copolymer (b) under presence of a peroxide polymerization initiator. When a polyvalent metal compound (c) is employed, 85 to 99.9 percent by weight of the copolymer (a) and 0.1 to 10 percent by weight of the ethylene-vinyl acetate copolymer (b) are graft-polymerized under presence of 0.01 to 5 percent by weight of the polyvalent metal compound (c) and a peroxide polymerization initiator.