TONER, IMAGE FORMING METHOD, AND PROCESS CARTRIDGE

• US 20120237868A1
• Filed: 02/24/2012
• Published: 09/20/2012
• Est. Priority Date: 03/14/2011
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Yamada, Saori, Aoki, Mitsuo, Nakajima, Hisashi, Nagayama, Masashi, Yaguchi, Shigenori
• Granted Patent: US 8,728,696 B2
• Time in Patent Office: Days
• US Class Current: 430/108.21
• CPC Class Codes: G03G 21/18 using a processing cartridge , whereby the process cartridge comprises at least two image processing means in a single unit
• CPC Class Codes: G03G 9/0821 characterised by physical parameters magnetic parameters G03G9/083
• CPC Class Codes: G03G 9/08755 Polyesters
• CPC Class Codes: G03G 9/08782 Waxes
• CPC Class Codes: G03G 9/08795 characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants
• CPC Class Codes: G03G 9/08797 characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature
• CPC Class Codes: G03G 9/0902 Inorganic compounds
• CPC Class Codes: G03G 9/0906 Organic dyes
• 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

Abstract

A toner including a binder resin, a colorant, and a release agent is provided. The toner has a peak loss tangent (tan δ) value of 3 or more within a temperature range of 80 to 160° C. Here, the loss tangent (tan δ) is a ratio (G″/G′) of a loss elastic modulus (G″) to a storage elastic modulus (G′). The toner provides a good combination of low-temperature fixability, hot offset resistance, storage stability, coloring power and/or opacifying power, and gloss.

Claims

1. A toner, comprising:

a binder resin;

a colorant; and

a release agent,

wherein the toner has a peak loss tangent (tan δ

) value of 3 or more within a temperature range of 80 to 160°

C., the loss tangent (tan δ

) being a ratio (G″

/G′

) of a loss elastic modulus (G″

) to a storage elastic modulus (G′

).

2. The toner according to claim 1, wherein the binder resin includes a crystalline polyester resin.

3. The toner according to claim 1, wherein the release agent includes a fatty acid amide.

4. The toner according to claim 3, wherein the fatty acid amide includes N,N′

-ethylene-bis stearic acid amide.

5. The toner according to claim 1, wherein the colorant is a white pigment.

6. The toner according to claim 5, wherein the white pigment is an organic white pigment.

7. The toner according to claim 6, wherein the organic white pigment is N,N-bis(4,6-1,3,5-triazine-2-yl)ethylenediamine.

8. The toner according to claim 5, wherein the toner includes the white pigment in an amount of 10 to 70% by weight.

9. The toner according to claim 1, wherein the colorant is a magenta pigment.

10. The toner according to claim 1, wherein the colorant is a cyan pigment.

11. The toner according to claim 1, wherein the colorant is a yellow pigment.

12. The toner according to claim 1, wherein the colorant is a black pigment.

13. The toner according to claim 1, wherein the colorant is a metallic pigment.

14. The toner according to claim 13, wherein the metallic pigment is a gold bronze pigment.

15. The toner according to claim 13, wherein the metallic pigment is an aluminum pigment.

16. The toner according to claim 13, wherein the metallic pigment is a mica pigment covered with a metal oxide.

17. The toner according to claim 1, wherein the colorant is a fluorescent colorant.

18. An electrophotographic image forming method, comprising:

charging an image bearing member;

irradiating the charged image bearing member with light containing image information to form an electrostatic latent image is thereon;

developing the electrostatic latent image into a toner image with the toner according to claim 1;

transferring the toner image from the image bearing member onto a recording medium; and

fixing the toner image on the recording medium.

19. A process cartridge detachably attachable to image forming apparatus, comprising:

an image bearing member to bear an electrostatic latent image; and

a developing device to develop the electrostatic latent image into a toner image with the toner according to claim 1.