BINDER FOR ELECTROPHOTOGRAPHIC TONER

摘要

PROBLEM TO BE SOLVED: To provide the electrophotographic toner binder capable of forming a sharp image even in a high-speed copying machine by using the toner binder made of a specified silicone type graft copolymer. SOLUTION: The electrophotographic toner binder is made of the silicone type graft copolymer obtained by copolymerizing an organopolysiloxane macromonomer represented by the formula with the other radically polymerizable monomer copolymerizable with this monomer. In the formula, R<1> is an oxygen atom or a methyl group; R<2> is a 1-6C univalent hydrocarbon group; (m) is an integer of 1-3; and (n) is an integer satisfying the following inequality: 20<=n<=200. As the monomer copolymerizable with this macromonomer, styrenes and their derivatives, acrylates and methacrylates are preferable from the view point of easiness in manufacture.