Electrostatic charge image developing toner and method of manufacturing the same
Provided is a method of manufacturing toner by which the toner capable of forming high quality images and reproducing high density gradation, which exhibits an excellent high-temperature offsetting property together with excellent low-temperature fixability, and provides appropriate gloss with respect to images to be formed, can be stably prepared; and also provided is the toner. After conducting a step in which particles made of at least a crystalline polyester resin are coagulated to form core coagulated particles, and an unsaturated amorphous polyester resin particle is attached onto the surface of each of the core coagulated particles to form core-shell type coagulated particles, radical polymerization reaction is conducted by acting a radical polymerization initiator on the foregoing core-shell type coagulated particles to conduct a step in which a layer made of a crosslinking amorphous polyester resin is formed on the surface of each of the core coagulated particles.
1. A method of manufacturing an electrostatic charge image developing toner comprising a toner particle containing a binder resin comprising an amorphous polyester resin having a crosslinking structure and a crystalline polyester resin, comprising the steps of:
(a-1) preparing an aqueous medium dispersion of crystalline polyester resin particles;
(a-2) preparing another aqueous medium dispersion of amorphous polyester resin particles, the amorphous polyester resin comprising a polymerizable unsaturated bond;
(b) coagulating at least the crystalline polyester resin particles in an aqueous medium to form core coagulated particles;
(c) attaching the amorphous polyester resin particles onto a surface of each of the core coagulated particles to form core-shell type coagulated particles; and
(d) subsequently conducting radical polymerization reaction via a radical polymerization initiator on the core-shell type coagulated particles to form a layer made of the amorphous polyester resin having a crosslinking structure on the surface of each of the core coagulated particles.
2. The method of claim 1 , further comprising the step of:
(e) adding a coagulation-termination agent between the steps (c) and (d).
3. The method of claim 2 , wherein
the radical polymerization in the step (d) is conducted at a temperature of not less than 50° C. and not more than a melting point of the crystalline polyester resin.
4. The method of claim 3 ,
wherein the crystalline polyester resin in the toner particle has a content of 20-70% by weight.
5. The method of claim 2 ,
wherein the amorphous polyester resin comprising a polymerizable unsaturated bond has a content of 10-60% by weight, based on a total weight of toner particles.
6. The method of claim 2 ,
wherein the amorphous polyester resin comprising a polymerizable unsaturated bond has a softening point of 80-180° C.
7. The method of claim 2 ,
wherein a part of the amorphous polyester resin is the amorphous polyester resin
comprising a polymerizable unsaturated bond.
8. The method of claim 2 ,
wherein the toner has a softening point of 80-110° C.
9. The method of claim 2 , wherein all of the amorphous polyester resin is the amorphous polyester resin comprising a polymerizable unsaturated bond.