Toner, process cartridge, developer, and image forming apparatus

摘要

A toner including a polyester resin having an amorphous polyester segment is provided. The amorphous polyester segment includes a condensation polymerization product between a carboxylic acid and an alcohol. The carboxylic acid includes both aliphatic and aromatic dicarboxylic acids. The toner deforms with a deformation rate of from 1.0% to 5.0% under a pressure of 100 gf at 40° C. and 80% RH. In a binarized image of an AFM phase image of the toner, first phase-contrast images serving as large-phase-difference portions are dispersed in second phase-contrast images serving as small-phase-difference portions, and the first phase-contrast images have a dispersion diameter of 100 nm or less. An endothermic quantity Q1 obtained in a first heating of DSC is from 10 to 50 J/g, and a ratio of an endothermic quantity obtained in the second heating Q2 to that in first heating Q1 is 0.65 or less.

主权项

1. A toner, comprising:
a binder resin comprising a polyester resin, wherein the polyester resin is a copolymer having an amorphous polyester segment and a crystalline segment, the amorphous polyester segment being obtained by condensation polymerization of an alcohol and a carboxylic acid including an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid, when the toner is subjected to a pressure of 100 gf at a temperature of 40° C. and a relative humidity of 80%, the toner deforms with a deformation rate of from 1.0% to 5.0%, when the toner is observed with an atomic force microscope in tapping mode to obtain a phase image and the phase image is binarized by using an intermediate value between maximum and minimum phase difference values to obtain a binarized image, the binarized image consists of first phase-contrast images serving as large-phase-difference portions and second phase-contrast images serving as small-phase-difference portions with the first phase-contrast images dispersed in the second phase-contrast images and the first phase-contrast images having a dispersion diameter of 100 nm or less, and when the toner is subjected to a differential scanning calorimetric measurement, an endothermic quantity Q1 measured in a first heating is from 10 to 50 J/g, and a ratio Q2/Q1 of an endothermic quantity Q2 measured in a second heating to the endothermic quantity Q1 measured in the first heating is 0.65 or less.