IP Library Granted Patent US 8,486,598
Granted Patent B2
US 8,486,598 · App. 12/950,158 · Granted Jul 16, 2013

Electrophotographic toner

Inventors: Takayasu Aoki (Shizuoka-ken, JP); Yasuhito Noda (Shizuoka-ken, JP); Koji Imamiya (Kanagawa-ken, JP); Tsuyoshi Itou (Shizuoka-ken, JP); Noboru Furuyama (Kanagawa-ken, JP)
Assignees: Kabushiki Kaisha Toshiba; Toshiba Tec Kabushiki Kaisha
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Quick Facts
Patent No.
US 8,486,598
App. No.
12/950,158
Granted
Jul 16, 2013
Kind
B2
Abstract

An electrophotographic toner contains an electron donating color former compound, an electron accepting color developing agent, and a polyester binder resin having a weight average molecular weight Mw of 6000 or more and 25000 or less, and the toner is decolorized by heating.

Claims (19)

1. An electrophotographic toner, which is decolorized by heating, comprising an electron donating color former compound, an electron accepting color developing agent, and a polyester binder resin having a weight average molecular weight Mw of 6000 or more and 25000 or less.

2. The toner according to claim 1 , wherein the toner has a glass transition point of 35° C. or higher and 65° C. or lower.

3. The toner according to claim 1 , wherein the toner has a softening point of 80° C. or higher and 120° C. or lower.

4. The toner according to claim 1 , wherein the toner has a toluene insoluble content of 10% by mass or more and 40% by mass or less.

5. The toner according to claim 1 , wherein the toner has an acid value of 25 mgKOH/g or less.

6. The toner according to claim 1 , further comprising a temperature control agent.

7. The toner according to claim 6 , wherein at least the electron donating color former compound, the electron accepting color developing agent, and the temperature control agent are microencapsulated.

8. The toner according to claim 1 , wherein the toner is decolorized at a temperature higher than the fixing temperature of the toner.

9. The toner according to claim 1 , further comprising at least one type of fine particles having an average primary particle diameter of 50 nm or more and 200 nm or less, wherein the coverage of toner particles of the toner with the fine particles having an average primary particle diameter of 50 nm or more and 200 nm or less is 30% or less per fine particles of one kind of substance, and the coverage of the toner particles with all of the fine particles is 50% or more and 150% or less.

10. The toner according to claim 9 , wherein the fine particles comprise any of silica, titania, alumina, strontium titanate, and tin oxide.

11. The toner according to claim 1 , wherein the electron donating color former compound is a leuco dye.

12. A toner cartridge containing the electrophotographic toner according to claim 1 .

13. An image forming apparatus comprising the electrophotographic toner according to claim 1 .

14. An electrophotographic toner, which is decolorizable with heat, comprising an electron donating color former compound, an electron accepting color developing agent, and a polyester binder resin having a weight average molecular weight Mw of 6000 or more and 25000 or less.

15. The toner according to claim 14 , further comprising a temperature control agent.

16. The toner according to claim 15 , wherein at least the electron donating color former compound, the electron accepting color developing agent, and the temperature control agent are microencapsulated.

17. The toner according to claim 14 , wherein the toner is decolorized with heat which make the temperature control agent heated to a temperature not lower than the melting point of the temperature control agent.

18. A toner cartridge containing the electrophotographic toner according to claim 14 .

19. An image forming apparatus comprising the electrophotographic toner according to claim 14 .

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 19, 2010
From: AOKI, TAKAYASU; NODA, YASUHITO; IMAMIYA, KOJI; ITOU, TSUYOSHI; FURUYAMA, NOBORU
To: TOSHIBA TEC KABUSHIKI KAISHA
Reel/Frame 025377/0526 →
Continuity (3)
Provisional Application 61263499 · Nov 23, 2009
Provisional Application 61323613 · Apr 13, 2010
Related Publication 20110123921A1 · May 26, 2011