Patent ID: 9069270
Filing Date: 2015-06-30
Classification: C09B,G03G

Abstract:
1. A toner for electrostatic latent image development, wherein the toner is prepared by aggregating at least fine particles comprising a binder resin, pigment fine particles, and fine particles comprising a release agent, to thereby obtain fine particle aggregates and then coalescing the fine particle aggregates, the binder resin is an amorphous a copolyester of 25 mole % of polyoxypropylene (2,2)-2,2-bis(4-hydroxyphenyl)propane 25 mole % of polyoxyethylene (2,0)-2,2-bis(4-hydroxyphenyl)propane, 46 mole % of fumaric acid and 4 mole % of trimellitic acid, a number average molecular mass of the amorphous copolyester is 2,500, a mass average molecular mass of the amorphous copolyester is 6,500, a softening point of the amorphous copolyester is 91° C., glass transition point of the amorphous copolyester is 51° C., an acid value of the amorphous copolyester is 15.5 mg KOH/g, the fine particles comprising the binder resin are fine particles prepared by microparticulation of the binder resin together with a polyoxyethylene alkylether sulfate, and the pigment fine particles have an average primary particle diameter of 50 nm or less, a Cv value of less than 20%, and an average circularity of from 0.94 to 0.97.