US Patent 9309349 Toner

A toner has toner particles containing a binder resin that comprises a block polymer as a main component, obtained by chemically bonding a crystalline polyester resin with an amorphous polyurethane resin, wherein the binder resin has a specific content of a crystalline polyester resin component, and has a concentration of ester bonds derived from the crystalline polyester resin component of not more than 5.2 mmol/g, and The maximum value EMAX of the flexural elasticity modulus E in a three-point bending test on the toner and the strain energy u for the toner satisfy specific values.