Electrostatic-image developing toner, electrostatic image developer, and toner cartridge
An electrostatic-image developing toner contains toner particles, each including a core particle and a shell layer disposed on at least a portion of a surface of the core particle. The core particle contains a first amorphous polyester resin containing structural units derived from a polycarboxylic acid and structural units derived from a polyol. About 5% by mass or less of the structural units derived from the polyol are structural units derived from a polyol containing a bisphenol-A backbone. The shell layer contains a second amorphous polyester resin containing structural units derived from a polycarboxylic acid and structural units derived from a polyol. About 50% by mass or more of the structural units derived from the polyol are structural units derived from a polyol containing a bisphenol-A backbone. The electrostatic-image developing toner has a water content of about 2.0% to about 5.0% by mass.
1. An electrostatic-image developing toner comprising toner particles, each comprising:
a core particle comprising a first amorphous polyester resin comprising structural units derived from a polycarboxylic acid and structural units derived from a polyol, wherein about 5% by mass or less of the structural units derived from the polyol are structural units derived from a polyol containing a bisphenol-A backbone; and
a shell layer disposed on at least a portion of a surface of the core particle, the shell layer comprising a second amorphous polyester resin comprising structural units derived from a polycarboxylic acid and structural units derived from a polyol, wherein about 50% by mass or more of the structural units derived from the polyol are structural units derived from a polyol containing a bisphenol-A backbone,
the electrostatic-image developing toner having a water content of about 2.0% to about 5.0% by mass; wherein
the electrostatic-image developing toner has a melt viscosity A at 110° C. of about 1.0×10 4 to about 8.0×10 4 Pa·s.
2. The electrostatic-image developing toner according to claim 1 , wherein the electrostatic-image developing toner has a water content of about 2.4% to about 3.0% by mass.
3. The electrostatic-image developing toner according to claim 1 , wherein an ingredient composition for the first amorphous polyester resin includes an epoxy compound.
4. The electrostatic-image developing toner according to claim 1 , wherein an ingredient composition for the first amorphous polyester resin includes 1,5-pentanediol.
5. The electrostatic-image developing toner according to claim 1 , wherein an ingredient composition for the first amorphous polyester resin includes dodecenylsuccinic acid.
6. The electrostatic-image developing toner according to claim 1 , wherein the second amorphous polyester resin is present in an amount of about 50% to about 100% by mass in regions extending from surfaces of the toner particles to a depth of 1/10 of the volume average particle size of the toner particles.
7. The electrostatic-image developing toner according to claim 1 , wherein the toner particles have a glass transition temperature (Tg) of about 50° C. to about 70° C.
8. The electrostatic-image developing toner according to claim 1 , wherein the toner particles have an average circularity of about 0.94 to about 1.00.
9. The electrostatic-image developing toner according to claim 1 , wherein the first amorphous polyester resin has a glass transition temperature (Tg) of about 50° C. to about 80° C.
10. The electrostatic-image developing toner according to claim 1 , wherein the second amorphous polyester resin has a glass transition temperature (Tg) of about 50° C. to about 80° C.
11. The electrostatic-image developing toner according to claim 1 , wherein the first amorphous polyester resin has an ester group concentration M of about 0.01 to about 0.05, wherein the ester group concentration M is represented by equation 1:
Ester group concentration M = K/A equation 1
wherein K is the number of ester groups in the first amorphous polyester resin, and A is the number of atoms forming a polymer chain of the first amorphous polyester resin.
12. The electrostatic-image developing toner according to claim 1 , wherein the first amorphous polyester resin has a number average molecular weight of about 1,000 to about 10,000.
13. The electrostatic-image developing toner according to claim 1 , wherein the second amorphous polyester resin has a number average molecular weight of about 2,000 to about 100,000.
14. The electrostatic-image developing toner according to claim 1 , wherein the electrostatic-image developing toner has a ratio (A/B) of the melt viscosity A to a melt viscosity B of about 0.01 to about 0.5, wherein the melt viscosity B is measured at 110° C. after drying at 50° C. and 10% RH for 48 hours.
15. The electrostatic-image developing toner according to claim 1 , wherein the toner particles have a volume average particle size of about 5 to about 14 μm.
16. The electrostatic-image developing toner according to claim 1 , wherein the toner particles contain a release agent in an amount of about 1% to about 10% by mass.
17. An electrostatic image developer comprising the electrostatic-image developing toner according to claim 1 .
18. A toner cartridge attachable to and detachable from an image-forming apparatus, the toner cartridge containing the electrostatic-image developing toner according to claim 1 .