MAGENTA TONER FOR DEVELOPING ELECTROSTATIC IMAGE

• US 20080261141A1
• Filed: 03/07/2008
• Published: 10/23/2008
• Est. Priority Date: 04/17/2007
• Status: Active Grant

• Current Assignee: Konica Minolta Business Technologies Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Business Technologies Incorporated (Konica Minolta Inc.)
• Inventors: YASUKAWA, Hiroyuki, OBATA, Hiroaki, KOUYAMA, Mikio, HAYASHI, Kenji, KUSAKA, Natsuko
• Granted Patent: US 8,062,819 B2
• Time in Patent Office: Days
• US Class Current: 430/108.21
• CPC Class Codes: G03G 9/09 Colouring agents for toner particles
• CPC Class Codes: G03G 9/0908 Anthracene dyes
• CPC Class Codes: G03G 9/0912 Indigoid; Diaryl and Triaryl methane; Oxyketone dyes
• CPC Class Codes: G03G 9/0914 Acridine; Azine; Oxazine; Thiazine-;(Xanthene-) dyes
• CPC Class Codes: G03G 9/0916 Quinoline; Polymethine dyes
• CPC Class Codes: G03G 9/092 Quinacridones
• CPC Class Codes: G03G 9/0922 Formazane dyes; Nitro and Nitroso dyes; Quinone imides; Azomethine dyes
• CPC Class Codes: G03G 9/0926 characterised by physical or chemical properties
• CPC Class Codes: G03G 9/09378 Non-macromolecular organic compounds
• CPC Class Codes: G03G 9/09392 Preparation thereof

Abstract

A magenta toner for developing an electrostatic image composed of a binder and a colorant is disclosed. The toner contains a tone controlling agent having a peak of fluorescent spectrum from 380 to 500 nm. An image excellent in light fastness and durability can be obtained and high color reproducibility with sufficient transparency and chromaticness can be realized by the magenta toner.

Claims

1. A magenta toner for developing an electrostatic image comprising magenta color particles containing a binder and a magenta colorant, wherein the magenta color particles contain a tone controlling agent having a peak of fluorescent spectrum within the range of from 380 to 500 nm.

2. The magenta toner of claim 1, wherein the tone controlling agent is a compound represented by Formula 1, 2 or 3,

3. The magenta toner of claim 2, wherein the tone controlling agent is a compound represented by Formula 1,

4. The magenta toner of claim 3, wherein L is a group represented by one of the following formulas.

5. The magenta toner of claim 1, wherein the tone controlling agent is a compound represented by Formula 2,

6. The magenta toner of claim 5, wherein R³ is a mono-valent substituent containing a nitrogen atom-containing heterocyclic ring.

7. The magenta toner of claim 6, wherein R³ is a substituent containing a mono-valent triazine ring, triazole ring or pyrazole ring.

8. The magenta toner of claim 1, wherein an amount of the tone controlling agent is from 0.01 to 12% by weight of the magenta color particles.

9. The magenta toner of claim 8, wherein an amount of the tone controlling agent is from 1 to 8% by weight of the magenta color particles.

10. The magenta toner of claim 1, wherein the magenta colorant is an oil-soluble dye or a metal chalet dye.

11. The magenta toner of claim 1, wherein the oil soluble dye is a rhodamine compound.

12. The magenta toner of claim 1, wherein the magenta colorant is one selected from the group consisting of C. I. Pigment Reds 5, 48:

1, 53;

1, 57;

1, 122, 139, 144, 149, 166, 177 and 222, and C. I. Pigment Oranges 31 and 43.

13. The magenta toner of claim 1, wherein the magenta color particles has a core/shell structure.

14. The magenta toner of claim 13, wherein the core contains a binder resin and a magenta colorant and the shell contains a resin covering the core and substantially no magenta colorant.

15. The magenta toner of claim 13, wherein the core contains the tone controlling agent.

16. The magenta toner of claim 13, wherein the shell contains the tone controlling agent.

17. The magenta toner of claim 1, wherein a particle diameter of the magenta color particles is from 4 to 10 μ

m in volume-based median diameter.

18. The magenta toner of claim 1, wherein the magenta color particles contain magenta colorant fine particles dispersed in the magenta color particles.

19. The magenta toner of claim 18, wherein a volume-based median diameter of the magenta colorant fine particles is from 10 to 500 nm.

20. The magenta toner of claim 1, wherein a hue angle of a visible image formed by the magenta image represented by a L*a*b* system of color represention is from 320°

to 340°

, wherein L* is brightness, a* is hue in the green-red direction and b* is hue in the yellow-blue direction.