Patent ID: 6011119
Filing Date: 2000-01-04
Classification: G03G,Y10S

Abstract:
A resin composition for an electrophotographic charge control agent-free toner, comprising:5to 95 parts by weight of a high molecular weight vinyl copolymer having a weight average molecular weight of from 200,000 to 1,000,000 and a ratio of the weight average molecular weight to a number average molecular weight of from 8 to 300, and95 to 5 parts by weight of a low molecular weight vinyl copolymer having a weight average molecular weight of from 3,000 to 20,000; andat least one of said high molecular weight vinyl copolymer and said low molecular weight vinyl copolymer being a vinyl copolymer which has been obtained by conducting polymerization in the presence of a monomer (M) wherein said monomer (M) is contained in an amount of from 8 to 45 parts by weight in 100 parts by weight of monomers which make up said high molecular weight vinyl copolymer and wherein said monomer (M) is, in combination, 1 to 20 parts by weight of at least one monomer selected from the group consisting of maleic anhydride, itaconic anhydride, glutaconic anhydride and 2-carboxycinnamic anhydride the balance of monomer (M) being at least one of (meth) acryloyloxyalkyl dicarboxylic acid esters represented by the formula (1): ##STR2## wherein m stands for an integer of from 1 to 7, n stands for an integer of from 1 to 3, X represents H or CH.sub.3, and Y represents H, an alkyl group having 1 to 8 carbon atoms or a benzyl group wherein said polymerization is conducted in the presence of at least one polyfunctional monomer and polyfunctional initiator.