IP Library Granted Patent US 8,974,998
Granted Patent B2
US 8,974,998 · App. 13/232,021 · Granted Mar 10, 2015

Method of image forming with a photoreceptor and toner

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 8,974,998
App. No.
13/232,021
Granted
Mar 10, 2015
Kind
B2
Abstract

A method of forming an image including an electrophotographic photoreceptor and a toner, wherein a photosensitive layer in the electrophotographic photoreceptor includes an undercoat layer including metal oxide particles, a charge generation layer including hydroxygallium phthalocyanine, and a charge transport layer, and the toner contains toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 μm to 7.0 μm; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 μm to 3.56 μm satisfies—0.0517EXP(22.4/Dv50)≦Dns≦0.233EXP(17.3/Dv50) where Dv50 is the volume median diameter (μm) of the toner, and Dns is the percentage in number of toner particles having a particle diameter of from 2.00 μm to 3.56 μm.

Claims (22)

1. A method, comprising electrostatically charging an electrophotographic photoreceptor with a contact type charging device, exposing the electrostatically charged electrophotographic photoreceptor to form a latent image, developing the latent image with a toner, and transferring the developed image to a recording paper, wherein a photosensitive layer in the electrophotographic photoreceptor comprises an undercoat layer, a charge generation layer, and a charge transport layer, wherein the undercoat layer comprises metal oxide particles and the charge generation layer comprises hydroxygallium phthalocyanine having strong peaks at Bragg angles 2θ±0.2° of 7.4° and 28.2° in CuKα characteristic X-ray diffraction; the toner for developing an electrostatic charge image is a toner for developing an electrostatic charge image containing toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 μm to 7.0 μm; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 μm to 3.56 μm satisfies

0.0517EXP(22.4 /Dv 50)≦ Dns≦ 0.233EXP(17.3 /Dv 50)

where Dv50 is the volume median diameter (μm) of the toner, and Dns is the percentage in number of toner particles having a particle diameter of from 2.00 μm to 3.56 μm.

2. The method claim 1 , wherein the volume median diameter (Dv50) of the toner for developing an electrostatic charge image, is at least 5.4 μm.

3. The method of claim 1 , wherein in the toner for developing an electrostatic charge image, the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 μm to 3.56 μm is at most 6% in number.

4. The method of claim 1 , wherein the toner for developing an electrostatic charge image is one having toner matrix particles produced by radical polymerization in an aqueous medium.

5. The method of claim 4 , wherein the toner for developing an electrostatic charge image is one having toner matrix particles produced by an emulsion polymerization aggregation method.

6. The method of claim 1 , wherein the toner for developing an electrostatic charge image is one having toner matrix particles produced by fixing or depositing fine resin particles on core particles.

7. The method of claim 6 , wherein the fine resin particles contain wax.

8. The method of claim 1 , wherein the undercoat layer further comprises an electroconductive layer and an interlayer.

9. The method of claim 1 , wherein the undercoat layer is formed on an electroconductive substrate and wherein the electroconductive substrate comprises an aniodic oxide coating applied thereon.

10. A method, comprising electrostatically charging an electrophotographic photoreceptor with a contact type charging device, exposing the electrostatically charged electrophotographic photoreceptor to form a latent image, developing the latent image with a toner, and transferring the developed image to a recording paper, wherein the electrophotographic photoreceptor comprises an undercoat layer; the undercoat layer comprises a binder resin and metal oxide particles having a refractive index of at most 2.0; the volume average particle diameter of secondary particles of metal oxide aggregated in a liquid having the undercoat layer dispersed in a solvent having methanol and 1-propanol mixed in a weight ratio of 7:3, is at most 0.1 μm, and the cumulative 90% particle diameter is at most 0.3 μm; the toner for developing an electrostatic charge image is a toner for developing an electrostatic charge image containing toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 μm to 7.0 μm; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 μm to 3.56 μm satisfies

0.0517EXP(22.4 /Dv 50)≦ Dns≦ 0.233EXP(17.3 /Dv 50)

where Dv50 is the volume median diameter (μm) of the toner, and Dns is the percentage in number of toner particles having a particle diameter of from 2.00 μm to 3.56 μm.

11. The method claim 10 , wherein the volume median diameter (Dv50) of the toner for developing an electrostatic charge image, is at least 5.4 μm.

12. The method of claim 10 , wherein in the toner for developing an electrostatic charge image, the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 μm to 3.56 μm is at most 6% in number.

13. The method of claim 10 , wherein the toner for developing an electrostatic charge image is one having toner matrix particles produced by radical polymerization in an aqueous medium.

14. The method of claim 13 , wherein the toner for developing an electrostatic charge image is one having toner matrix particles produced by an emulsion polymerization aggregation method.

15. The method of claim 10 , wherein the toner for developing an electrostatic charge image is one having toner matrix particles produced by fixing or depositing fine resin particles on core particles.

16. The method of claim 15 , wherein the fine resin particles contain wax.

17. The method of claim 10 , wherein the undercoat layer further comprises an electroconductive layer and an interlayer.

18. The method of claim 10 , wherein the undercoat layer is formed on an electroconductive substrate and wherein the electroconductive substrate comprises an aniodic oxide coating applied thereon.

Assignments (2)
CHANGE OF NAME Recorded Sep 5, 2017
From: MITSUBISHI RAYON CO., LTD.
To: MITSUBISHI CHEMICAL CORPORATION
Reel/Frame 043750/0834 →
MERGER Recorded Sep 4, 2017
From: MITSUBISHI CHEMICAL CORPORATION
To: MITSUBISHI RAYON CO., LTD.
Reel/Frame 043750/0207 →