TONER AND METHOD FOR MANUFACTURING TONER

摘要

To provide a toner from which an image having a stable image density can be obtained with reduced occurrence of pollution of members, even when a toner container is filled with a larger amount of toner than a conventional amount for long-term use. A toner including a toner particle and an external additive containing an organic-inorganic composite fine particle and an inorganic fine particle A; wherein the organic-inorganic composite fine particle includes a resin particle and an inorganic fine particle B, the resin particle has a surface with a convex derived from the inorganic fine particle B; has a specific number average particle diameter (D1) and a specific shape factor SF-2; and has a specific fixed state to the toner particle; the organic-inorganic composite fine particle has a specific unit diffusion index on the toner particle surface; the inorganic fine particle A has a specific BET specific surface area.

主权项

1. A toner comprising a toner particle containing a binder resin, a colorant and a releasing agent, and an external additive containing an organic-inorganic composite fine particle and an inorganic fine particle A;
wherein the organic-inorganic composite fine particle: (1) comprises a resin particle and an inorganic fine particle B which is embedded in the resin particle, and has a surface with a convex portion derived from the inorganic fine particle B; (2) has a number average particle diameter (D1) of 50 nm or more and 500 nm or less; (3) has a shape factor SF-2 of 103 or more and 120 or less as measured at a magnification of 200000; and (4) has a proportion Y (parts by mass) of a particle firmly fixed to the toner particle of 0.45 parts by mass or more and 3.00 parts by mass or less with respect to 100 parts by mass of the toner particle; when a content proportion of the organic-inorganic composite fine particle is X parts by mass with respect to 100 parts by mass of the toner particle, the X and the Y satisfy the following expression:
X−Y≦0.30; the organic-inorganic composite fine particle has a unit diffusion index of 0.75 or more on the toner particle surface calculated from the following formula:
unit diffusion index=(organic-inorganic composite fine particle coverage ratio on toner particle surface obtained from measurement)/(organic-inorganic composite fine particle coverage ratio on toner particle surface for ideal diffusion of organic-inorganic composite fine particle); the inorganic fine particle A has a BET specific surface area of 50 m2/g or more and 400 m2/g or less.