Electrostatic charge image developing toner, electrostatic charge image developer, and toner cartridge
An electrostatic charge image developing toner includes toner particles including an amorphous resin and a crystalline resin, wherein, when the toner particles are subjected to a measurement by differential scanning calorimetry before and after being heated at a temperature of 50° C. and a humidity of 50% RH for a week, a relationship between an endothermic amount x (J/g) derived from the crystalline resin with respect to the toner particles before being heated and an endothermic amount y (J/g) derived from the crystalline resin with respect to the toner particles after being heated satisfies Expression (1): x/y<0.3.
1. An electrostatic charge image developing toner comprising:
toner particles including an amorphous polyester resin and a crystalline polyester resin,
wherein:
the toner particles have been subjected to an annealing treatment in which the toner particles are heated to an elevated temperature that is equal to or higher than a glass transition temperature of the amorphous polyester resin, maintained at the elevated temperature for 1 to 24 hours, and then cooled to room temperature at a rate of 1° C./min to 30° C./min, and
when the toner particles are subjected to a measurement by differential scanning calorimetry before and after being heated at a temperature of 50° C. and a humidity of 50% RH for a week, a relationship between an endothermic amount x (J/g) derived from the crystalline resin with respect to the toner particles before being heated and an endothermic amount y (J/g) derived from the crystalline resin with respect to the toner particles after being heated satisfies Expression (1): x/y<0.3.
2. The electrostatic charge image developing toner according to claim 1 ,
wherein a weight ratio between the amorphous polyester resin and the crystalline polyester resin (amorphous polyester resin/crystalline polyester resin) is from 50/50 to 97/3.
3. The electrostatic charge image developing toner according to claim 1 , wherein:
a glass transition temperature of the amorphous polyester resin is from 50° C. to 65° C., and
a melting temperature of the crystalline polyester resin is from 60° C. to 85° C.
4. The electrostatic charge image developing toner according to claim 1 ,
wherein the amorphous polyester resin is a urea-modified polyester resin.
5. The electrostatic charge image developing toner according to claim 1 ,
wherein the crystalline polyester resin is a polycondensate prepared by using a polymerizable monomer having a straight aliphatic group.
6. An electrostatic charge image developer comprising:
the electrostatic charge image developing toner according to claim 1 .
7. A toner cartridge comprising:
a container that contains the electrostatic charge image developing toner according to claim 1 ,
wherein the toner cartridge is detachable from an image forming apparatus.
8. The electrostatic charge image developing toner according to claim 1 , wherein the elevated temperature is higher than the glass transition temperature of the amorphous polyester resin by 10° C. or more.
9. The electrostatic charge image developing toner according to claim 1 , wherein the elevated temperature is higher than the glass transition temperature of the amorphous polyester resin by 20° C. or more.
10. The electrostatic charge image developing toner according to claim 1 , wherein in the annealing treatment, the toner particles are maintained at the elevated temperature for 2 to 10 hours.
11. The electrostatic charge image developing toner according to claim 1 , wherein in the annealing treatment, the toner particles are cooled at a rate of 10° C./min to 30° C./min.
12. The electrostatic charge image developing toner according to claim 1 , wherein in the annealing treatment, the toner particles are cooled at a rate of 1° C./min to 20° C./min.