IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

• US 20150253720A1
• Filed: 03/09/2015
• Published: 09/10/2015
• Est. Priority Date: 03/10/2014
• Status: Abandoned Application

• Current Assignee: Konica Minolta Inc.
• Original Assignee: Konica Minolta Inc.
• Inventors: KURIMOTO, Kazunori, KURACHI, Masahiko, ISHIDA, Takeshi, HATANO, Hokuto
• Application Number:
  US14/641,891
• Publication Number:
  US 20150253720A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G03G 15/75 Details relating to xerographic drum, band or plate, e.g. replacing, testing electrographic recording members per se G03G5/00
• CPC Class Codes: G03G 21/0005 for removing solid developer or debris from the electrographic recording medium
• CPC Class Codes: G03G 5/14704 comprising inorganic material
• CPC Class Codes: G03G 5/14734 Polymers comprising at least one carboxyl radical, e.g. polyacrylic acid, polycrotonic acid, polymaleic acid; Derivatives thereof, e.g. their esters, salts, anhydrides, nitriles, amides
• CPC Class Codes: G03G 5/14769 Other polycondensates comprising nitrogen atoms with or without oxygen atoms in the main chain
• CPC Class Codes: G03G 5/14773 Polycondensates comprising silicon atoms in the main chain
• CPC Class Codes: G03G 5/14791 Macromolecular compounds characterised by their structure, e.g. block polymers, reticulated polymers, or by their chemical properties, e.g. by molecular weight or acidity

Abstract

An image forming apparatus includes an electrophotographic photoreceptor, a proximity-type charging unit to negatively charge the surface of the photoreceptor, an exposing unit to form an electrostatic latent image on the surface of the photoreceptor, a developing unit to develop the electrostatic latent image with a toner to form a toner image, a transferring unit to transfer the toner image onto a transfer medium, a fixing unit to fix the transferred toner image on the transfer medium, and a cleaning unit to remove residual toner on the photoreceptor. The photoreceptor comprises a conductive support, a photosensitive layer formed over the conductive support, and a protective layer formed over the photosensitive layer. The protective layer of the photoreceptor contains a binder resin, a particulate P-type semiconductor, and a particulate cross-linked resin composed of an insulating cross-linked polymer.

Claims

1. An image forming apparatus comprising:

an electrophotographic photoreceptor;

a proximity-type charging unit to negatively charge a surface of the electrophotographic photoreceptor;

an exposing unit to form an electrostatic latent image on the surface of the electrophotographic photoreceptor;

a developing unit to develop the electrostatic latent image with a toner to form a toner image;

a transferring unit to transfer the toner image onto a transfer medium;

a fixing unit to fix the transferred toner image on the transfer medium; and

a cleaning unit to remove residual toner on the electrophotographic photoreceptor, wherein

the electrophotographic photoreceptor comprises a conductive support, a photosensitive layer formed over the conductive support, and a protective layer formed over the photosensitive layer; and

the protective layer of the electrophotographic photoreceptor contains a binder resin, a particulate P-type semiconductor, and a particulate cross-linked resin composed of an insulating cross-linked polymer.

2. The image forming apparatus according to claim 1, wherein the particulate P-type semiconductor is composed of a compound represented by Formula (1):

CuMO₂  

 

Formula (1);

where M represents an element belonging to Group 13 of a periodic table.

3. The image forming apparatus according to claim 1, wherein the particulate cross-linked resin is selected from a particulate silicone resin, a particulate melamine-formaldehyde condensation resin, and a particulate cross-linked polymer containing poly(methyl methacrylate).

4. The image forming apparatus according to claim 1, wherein a ratio A/B of a number average primary particle size A of the particulate cross-linked resin to a number average primary particle size B of the particulate P-type semiconductor satisfies Formula (2):

2≦

A/B≦

10.  

 

Formula (2);

5. The image forming apparatus according to claim 1, wherein the binder resin contained in the protective layer of the electrophotographic photoreceptor is a cured resin prepared through photopolymerization of a compound having two or more radically polymerizable functional groups.

6. The image forming apparatus according to claim 1, wherein the proximity-type charging unit is a charging roller.

7. The image forming apparatus according to claim 1, wherein the particulate P-type semiconductor has a number average primary particle size of 0.02 to 0.1 μ

m.

8. The image forming apparatus according to claim 1, wherein the particulate P-type semiconductor is contained in an amount of 50 to 150 parts by mass relative to 100 parts by mass of the binder resin in the protective layer.

9. The image forming apparatus according to claim 1, wherein the particulate cross-linked resin has a number average primary particle size of 0.1 to 1.0 μ

m.

10. An image forming method to form an image using an electrophotographic photoreceptor, the method comprising:

negatively charging a surface of the electrophotographic photoreceptor;

forming an electrostatic latent image on the surface of the electrophotographic photoreceptor;

developing the electrostatic latent image with a toner to form a toner image;

transferring the toner image onto a transfer medium;

fixing the transferred toner image on the transfer medium; and

removing residual toner on the electrophotographic photoreceptor, wherein

the electrophotographic photoreceptor comprises a conductive support, a photosensitive layer formed over the conductive support, and a protective layer formed over the photosensitive layer; and

the protective layer of the electrophotographic photoreceptor contains a binder resin, a particulate P-type semiconductor, and a particulate cross-linked resin composed of an insulating cross-linked polymer.