Patent ID: 8722296

Claim:
A toner for electrostatic image development having a binder resin comprising an amorphous polyester resin and a crystalline polyester resin, and a coloring agent, and the binder resin satisfies the following relationship (1): SP ( L )> SP ( H )> SP ( C ) (1) wherein SP(H) is the solubility parameter of the binder resin contained in an elution fraction F (0-10) from the beginning of elution of W 1 until 10% of the elution of W 1 when W 1 is the whole area of an elution curve on a gel permeation chromatograph measured for an acetone-soluble fraction of the toner; SP(L) is the solubility parameter of the binder resin contained in an elution fraction F (80-100) from 80% to 100% of the elution of W 1 ; SP(C) is the solubility parameter of the crystalline polyester resin, the crystalline polyester resin has a weight-average molecular weight of from about 6,000 to about 35,000, and a melting point of from about 60° C. to about 120° C., a content of the crystalline polyester resin in the toner is from 15.7 wt % to 33.5 wt % based on a weight of the toner, the amorphous polyester resin comprises an amorphous polyester resin (1) having a weight-average molecular weight of from 8,000 to 25,000 and an amorphous polyester resin (2) having a weight-average molecular weight of from 30,000 to 200,000, the solubility parameter of the amorphous polyester resin (1) is larger than the solubility parameter of the amorphous polyester resin (2), and the toner is produced by an emulsification aggregation method.