ELECTROPHOTOGRAPHIC TONER AND ITS MANUFACTURING METHOD, ELECTROPHOTOGRAPHIC DEVELOPER, AND IMAGE FORMING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an electrophotographic toner capable of low temperature fixing and having sufficient charging property (particularly under high temperature and high humidity conditions). SOLUTION: The electrophotographic toner is characterized in that: the toner has a structure including a core particle containing a crystalline resin and a shell layer covering the core particle; the storage modulus of the toner at 30°C is 1×108Pa; the mass of the shell layer is 10 to 60% of the mass of the core particle; and the toner satisfies the following conditions (1) and (2). Herein, (1) the resin of the shell layer consists of a copolymer obtained by polymerizing monomers containing an aromatic vinyl monomer and an aliphatic unsaturated carboxylate monomer, wherein the copolymer partially has a carboxyl group and the amount of the copolymer portion derived from the monomer having the carboxyl group is 0.04 mol% to 4.5 mol% of the entire resin components of the shell layer; and (2) such toner particles that at least 80% of the surface area thereof is coated with the shell layer having≥0.05μm thickness account at least 80% of the entire surface of toner particles. COPYRIGHT: (C)2006,JPO&NCIPI