IP Library › Granted Patent US 9,618,864
Granted Patent B2
US 9,618,864 · App. 14/330,109 · Granted Apr 11, 2017

Toner, image forming apparatus, image forming method, process cartridge, and developer

Inventors: Hideki Sugiura (Shizuoka, JP); Yuka Mizoguchi (Shizuoka, JP); Mio Kumai (Shizuoka, JP)
Assignee: Ricoh Company, Ltd.
G03G9/08755G03G9/0806G03G9/0819G03G9/0825G03G9/0827G03G9/08795G03G9/08797G03G9/093G03G9/09392
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Quick Facts
Patent No.
US 9,618,864
App. No.
14/330,109
Granted
Apr 11, 2017
Kind
B2
Abstract

A toner comprised of mother toner particles each including a colorant, a resin A capable of forming a crystalline structure, and a resin B incapable of forming a crystalline structure is provided. The resin A is dispersed in the resin B in the state of phase separation. The long axis of each dispersed particle of the resin A has a length of from 30 to 200 nm and the length ratio of the long axis to the short axis is from 2 to 15. The DSC endothermic quantity attributable to the resin A is from 8 to 20 J/g.

Claims (29)

1. A toner, comprising mother toner particles including:

a colorant;

a crystalline resin A,

an amorphous resin B, and

ethyl acetate in an amount of from 1 to 30 μg per 1 gram of the toner;

wherein the crystalline resin A is dispersed in the amorphous resin B in the state of phase separation,

wherein a long axis of each dispersed particle of the crystalline resin A has a length of from 30 to 200 nm and a length ratio of the long axis to a short axis is from 2 to 15, and

wherein a DSC endothermic quantity attributable to the crystalline resin A is from 8 to 20 J/g.

2. The toner according to claim 1 , wherein each of the mother toner particles has a core-shell structure.

3. The toner according to claim 1 , wherein the toner includes a polyester resin.

4. The toner according to claim 1 , wherein the toner includes a modified polyester resin.

5. The toner according to claim 1 , wherein the mother toner particles have an average circularity E of from 0.93 to 0.99.

6. The toner according to claim 1 , wherein a weight average particle diameter D4 of the toner is from 2 to 7 μm and a ratio (D4/Dn) of the weight average particle diameter D4 to a number average particle diameter Dn of the toner is from 1.00 to 1.25.

7. The toner according to claim 1 , wherein the toner is produced by a process including granulating in a medium containing water and/or an organic solvent.

8. The toner according to claim 1 , wherein the mother toner particles are produced by a dissolution suspension method.

9. The toner according to claim 1 , wherein the mother toner particles are produced by a dissolution suspension method accompanied by an elongation reaction.

10. The toner according to claim 1 , wherein the mother toner particles are produced by dispersing and/or emulsifying an organic phase and/or monomer phase in an aqueous medium, the organic phase and/or monomer phase including raw materials and/or precursors of the mother toner particles.

11. The toner according to claim 1 , wherein the mother toner particles are produced by subjecting a toner composition to a cross-linking and/or elongation reaction in an aqueous medium in the presence of fine resin particles, the toner composition including a polymer having a site reactive with a compound having an active hydrogen group, a polyester, a colorant, and a release agent.

12. A process cartridge, comprising:

a latent image bearing member;

a developing device; and

the toner according to claim 1 ,

wherein the process cartridge integrally supports the latent image bearing member and the developing device and is detachably attachable to image forming apparatus.

13. A two-component developer, comprising:

the toner according to claim 1 ; and

a magnetic carrier.

14. The toner according to claim 1 , having an average circularity of from 0.93 to 0.98.

15. The toner according to claim 1 , wherein a long axis of the crystalline resin A is from 31 to 190 nm.

16. The toner according to claim 1 , the ethyl acetate is present in an amount of from 3 to 22 μg per 1 gram of the toner.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 14, 2014
From: SUGIURA, HIDEKI; MIZOGUCHI, YUKA; KUMAI, MIO
To: RICOH COMPANY, LTD.
Reel/Frame 033304/0420 →
Priority Claims (2)
JP 2013-185446 · Sep 6, 2013 · national
JP 2014-071853 · Mar 31, 2014 · national
Continuity (1)
Related Publication 20150072277A1 · Mar 12, 2015