Toner, image forming apparatus, process cartridge, and developer

Patent metadata

Field	Value
Publication number	US-9618865-B2
Application number	US-201414771309-A
Country	US
Kind code	B2
Filing date	Mar 13, 2014
Priority date	Mar 15, 2013
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A toner, including: a colorant; and a binder resin, wherein a spreadability of the toner under a non-pressurized condition is 1.20 to 2.50, wherein a common logarithm of a storage modulus at 100° C. (G′) of the toner is 4.0 [log Pa] to 5.0 [log Pa], and wherein a ratio of a loss modulus at 100° C. (G″) to the storage modulus at 100° C. (G′) of the toner (G″/G′=tan δ) is 1.1 to 2.2.

First claim

The invention claimed is:

1. A toner, comprising:
toner base particles having a core-shell structure and comprising:
a colorant; and
a binder resin,

wherein an average value of ratios of particle areas at 100° C. to particle areas at 25° C. when the toner is heated from 25° C. to 100° C. at a rate of 10° C./min under a non-pressurized condition is 1.20 to 2.50,
wherein a common logarithm of a storage modulus at 100° C. (G′) of the toner is 4.0 [log Pa] to 5.0 [log Pa], and
wherein a ratio of a loss modulus at 100° C. (G″) of the toner to the storage modulus at 100° C. (G′) of the toner, which is expressed by G″/G′ equal to tan δ, is 1.1 to 2.2.

2. The toner according to claim 1 , wherein a degree of crystallinity of the toner is 10% or more.

3. The toner according to claim 1 , further comprising ethyl acetate, wherein a content of the ethyl acetate is 1 μg/g to 30 μg/g.

4. The toner according to claim 1 , wherein the binder resin comprises polyester.

5. The toner according to claim 4 , wherein the polyester comprises a urea-modified polyester.

6. The toner according to claim 4 , wherein the polyester comprises a crystalline polyester.

7. The toner according to claim 1 , wherein an average circularity of the toner is 0.93 to 0.99.

8. The toner according to claim 1 , wherein a weight average particle diameter of the toner is 2 μm to 7 μm, and wherein a ratio of the weight average particle diameter to a number average particle diameter of the toner is 1.00 to 1.25.

9. The toner according to claim 1 , wherein the toner is produced by dispersing a solution or dispersion liquid into an aqueous medium in which a vinyl-based resin is dispersed, and wherein the solution or dispersion liquid is produced by dissolving or dispersing a composition containing an isocyanate group-containing polyester prepolymer, amines, polyester, the colorant, and a releasing agent into an organic solvent.

10. An image forming apparatus, comprising:
a photoconductor;
a charging unit configured to charge the photoconductor;
an exposing unit configured to expose the photoconductor charged to light, to thereby form an electrostatic latent image;
a developing unit containing the toner according to claim 1 , and configured to develop the electrostatic latent image which has been formed on the photoconductor with the toner, to thereby form a toner image;
a transfer unit configured to transfer the toner image which has been formed on the photoconductor onto a recording medium; and
a fixing unit configured to fix the toner image which has been transferred onto the recording medium.

11. A process cartridge, comprising:
a photoconductor; and
a developing unit containing the toner according to claim 1 , and configured to develop the electrostatic latent image which has been formed on the photoconductor with the toner;
wherein the photoconductor and the developing unit are integrally supported, and
wherein the process cartridge is attachable to and detachable from a main body of an image forming apparatus.

12. A developer, comprising:
the toner according to claim 1 ; and
a carrier.

13. The toner according to claim 1 , wherein an average value of ratios of particle areas at 100° C. to particle areas at 25° C. when the toner is heated from 25° C. to 100° C. at a rate of 10° C./min under a non-pressurized condition is 1.30 to 2.20.

14. The toner according to claim 1 , further comprising ethyl acetate, wherein a content of the ethyl acetate is 5 μg/g to 17 μg/g.

15. The toner according to claim 1 , wherein a degree of crystallinity of the toner is 30% or more.

16. The toner according to claim 1 , wherein:
an average circularity of the toner is 0.93 to 0.99;
a weight average particle diameter of the toner is 2 μm to 7 μm;
a ratio of the weight average particle diameter to a number average particle diameter of the toner is 1.00 to 1.25;
an average value of ratios of particle areas at 100° C. to particle areas at 25° C. when the toner is heated from 25° C. to 100° C. at a rate of 10° C./min under a non-pressurized condition is 1.30 to 2.20; and
a degree of crystallinity of the toner is 30% or more.

17. An image forming apparatus, comprising:
a photoconductor;
a charging unit configured to charge the photoconductor;
an exposing unit configured to expose the photoconductor charged to light, to thereby form an electrostatic latent image;
a developing unit containing the toner according to claim 16 , and configured to develop the electrostatic latent image which has been formed on the photoconductor with the toner, to thereby form a toner image;
a transfer unit configured to transfer the toner image which has been formed on the photoconductor onto a recording medium; and
a fixing unit configured to fix the toner image which has been transferred onto the recording medium.

18. A process cartridge, comprising:
a photoconductor; and
a developing unit containing the toner according to claim 16 , and configured to develop the electrostatic latent image which has been formed on the photoconductor with the toner;
wherein the photoconductor and the developing unit are integrally supported, and
wherein the process cartridge is attachable to and detachable from a main body of an image forming apparatus.

19. A developer, comprising:
the toner according to claim 16 ; and
a carrier.

Assignees

• Sugiura Hideki
• Kumai Mio
• Ricoh Co Ltd

Inventors

• Sugiura Hideki
• Kumai Mio

Classifications

• G03G9/0825

  characterised by their structure; characterised by non-homogenuous distribution of components (microcapsular toners G03G9/093) · CPC title

• G03G9/08755 Primary

  Polyesters · CPC title

• G03G9/08795

  characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants · CPC title

• G03G9/08797

  characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature · CPC title

• G03G9/09371

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds · CPC title