Patent ID: 7575841

Claim:
A toner for electrophotography having a capsule structure comprising a core and a shell that covers the core, wherein the core contains a colorant, a releasing agent, an amorphous resin, and a block polymer containing a crystalline part and an amorphous part, the weight-average molecular weight of the block polymer is 10,000 or more, the weight-average molecular weight of the resin used in formation of the amorphous part of the block polymer is 1000 to 5000, and the weight-average molecular weight of the resin used in formation of the crystalline part of the block polymer is at least 2 times the weight-average molecular weight of the resin used in formation of the amorphous part of the block polymer, and wherein the resin used in formation of the crystalline part of the block copolymer is an aliphatic crystalline polyester having an ester concentration of 0.12 or less as expressed in formula (1): Ester concentration( M )= K/A (Formula (1)) wherein K is a number of ester groups in a polymer, and A is a number of atoms composing a polymer chain of the polymer.