Magenta toner for electrophotography, developer, toner cartridge, process cartridge, image forming apparatus, and image forming method
View Patent ↗A magenta toner for electrophotography, including: toner particles containing, a polyester resin, a coloring agent containing a solid solution of C.I. Pigment Violet 19 and C.I. Pigment Red 122, a release agent, and inorganic particles; and an external additive, wherein an average particle diameter of the inorganic particle is 0.75 times or more the average particle diameter of the coloring agent.
1. A magenta toner for electrophotography, comprising:
toner particles containing:
a polyester resin,
a coloring agent containing a solid solution of C.I. Pigment Violet 19 and C.I. Pigment Red 122,
a release agent, and
inorganic particles; and
an external additive,
wherein:
an average particle diameter of the inorganic particles is 0.75 times or more the average particle diameter of the coloring agent;
the inorganic particles have an average particle diameter of from 105 nm to 310 nm;
the inorganic particles are silica; and
the inorganic particles are present in an amount of from 0.3% by mass to 10% by mass in the toner particles.
2. The magenta toner for electrophotography of claim 1 , wherein the release agent has a melting temperature of from 70° C. to 100° C.
3. The magenta toner for electrophotography of claim 1 , wherein the release agent is Fischer-Tropsch wax.
4. The magenta toner for electrophotography of claim 1 , wherein an amount of the release agent is from 1 part by mass to 15 parts by mass based on 100 parts by mass of the polyester resin.
5. The magenta toner for electrophotography of claim 1 , wherein an amount of the solid solution is from 2% by mass to 30% by mass in the toner particles.
6. The magenta toner for electrophotography of claim 1 , wherein a ratio by mass of C.I. Pigment Violet 19 and C.I. Pigment Red 122 is 80:20 to 20:80.
7. The magenta toner for electrophotography of claim 1 , further comprising C.I. Pigment Red 238 or C.I. Pigment Red 269.
8. The magenta toner for electrophotography of claim 7 , wherein a ratio of the C.I. Pigment Red 238 and the C.I. Pigment Red 269 is from 30 parts by mass to 500 parts by mass based on 100 parts by mass of the solid solution.
9. The magenta toner for electrophotography of claim 1 , wherein the external additive contains silica.
10. The magenta toner for electrophotography of claim 9 , wherein the silica has a primary particle diameter of from 0.01 μm to 0.5 μm.
11. The magenta toner for electrophotography of claim 9 , wherein the external additive further contains a lubricant.
12. The magenta toner for electrophotography of claim 11 , wherein the lubricant has a primary particle diameter of from 0.5 μm to 8.0 μm.
13. A magenta developer for electrophotography, comprising the magenta toner for electrophotography of claim 1 .
14. An image forming method, comprising:
charging a surface of the latent image holding member,
forming an electrostatic latent image on the surface of the latent image holding member,
developing the electrostatic latent image with the developer of claim 13 to form a toner image,
transferring the toner image onto a recording medium, and
fixing the toner image onto the recording medium.
15. The image forming method of claim 14 , wherein a fixing pressure in the fixing process is 4.0 kgf/cm 2 or more.
16. The image forming method of claim 14 , wherein a process speed is 300 mm/sec or more.
17. The magenta toner for electrophotography of claim 1 , wherein the inorganic particles have an average particle diameter of from 125 nm to 290 nm.