Toner, developer, process cartridge, and image forming apparatus

摘要

A toner, including: a binder resin; releasing agent-encapsulating capsules; and a colorant, wherein the releasing agent-encapsulating capsules each include: a capsule formed of a resin (I) which is different from the binder resin; and a releasing agent (RA) which is encapsulated in the capsule, and the releasing agent-encapsulating capsules exist in the binder resin, and wherein 50% to 100% of the releasing agent-encapsulating capsules exist in a region from a surface of the toner to a depth of 0.10 times a volume-average particle diameter of the toner.

主权项

1. A toner, comprising:
a binder resin comprising a non-crystalline resin (R), which comprises a polyester skeleton; releasing agent-encapsulating capsules; and a colorant, wherein the releasing agent-encapsulating capsules each comprise: a capsule formed of a resin (I) which is different from the binder resin and of a polyolefin resin (D) comprising a vinyl monomer; and a releasing agent (RA) which is encapsulated in the capsule, wherein an absolute value of a difference between a solubility parameter of the polyolefin resin (D) and a solubility parameter of the release agent (RA) is less than 2, wherein the releasing agent-encapsulating capsules exist in the binder resin, wherein 50% to 100% of the releasing agent-encapsulating capsules exist in a region from a surface of the toner to a depth of 0.10 times a volume-average particle diameter of the toner, wherein the vinyl monomer of the resin (D) comprises an ester group introduced in an oil-soluble component, wherein an average ester-group concentration of the vinyl monomer calculated by Formula (1) is from 13.2% by mass to 30% by mass:
Ester-group concentration=Σ(44/Mwi ×Wi)  Formula (1) wherein Mwi is a molecular weight of the vinyl monomer comprising the ester group, and wherein Wi is a charge ratio (% by mass) of the vinyl monomer comprising the ester group.