Developing roller, and developing device, process cartridge and image forming method and apparatus using the developing roller

Patent metadata

Field	Value
Publication number	US-9026015-B2
Application number	US-201414160652-A
Country	US
Kind code	B2
Filing date	Jan 22, 2014
Priority date	Jan 30, 2013
Publication date	May 5, 2015
Grant date	May 5, 2015

Abstract

A developing roller to bear toner thereon is provided. The developing roller includes a cylindrical electroconductive substrate; an electroconductive elastic layer located on a peripheral surface of the cylindrical electroconductive substrate; and a toner bearing layer located on a peripheral surface of the electroconductive elastic layer. The toner bearing layer includes a polyurethane resin, which is a reaction product of at least an isocyanate compound having an isocyanurate structure and a polyol at a NCO/OH molar ratio of from 90 to 110. The toner bearing layer has a water contact angle of from 135° to 155°, and a static friction coefficient of from 0.10 to 0.15.

First claim

What is claimed is:

1. A developing roller comprising:
a cylindrical electroconductive substrate;
an electroconductive elastic layer located on a peripheral surface of the cylindrical electroconductive substrate; and
a toner bearing layer located on a peripheral surface of the electroconductive elastic layer,
wherein the toner bearing layer includes a polyurethane resin which is a reaction product of at least an isocyanate compound having an isocyanurate structure and a polyol at a NCO/OH molar ratio of from 90 to 110, and the toner bearing layer has a water contact angle of from 135° to 155°, and a static friction coefficient of from 0.10 to 0.15.

2. The developing roller according to claim 1 , wherein the polyurethane resin is a reaction product of a polyisocyanurate prepolymer having an isocyanurate structure, a polyol, and at least one of a compound having a fluorine-containing group or a silicone-based functional group, and a compound having an alkyl group in a side chain thereof.

3. The developing roller according to claim 2 , wherein the compound having a fluorine-containing group or a silicone-based functional group is a compound selected from fluoroethylene vinyl ether copolymers, carboxylic acids having a perfluoroalkyl group, alcohols having a perfluoroalkyl group, amines having a perfluoroalkyl group, and silane coupling agents having a perfluoroalkyl group.

4. The developing roller according to claim 2 , wherein the compound having an alkyl group in a side chain thereof is a compound selected from alcohols having an alkyl group, and amines having an alkyl group.

5. The developing roller according to claim 2 , wherein the polyisocyanate prepolymer having an isocyanurate structure includes at least one of isocyanurate of hexamethylene diisocyanate and isocyanurate of tolylene diisocyanate.

6. The developing roller according to claim 1 , wherein the polyurethane resin is a reaction product of a poly isocyanate prepolymer having an isocyanurate structure, and a polyol having at least one of a fluorine-containing group, a silicone-based functional group, and an alkyl group, which is included in a side chain thereof.

7. A developing device comprising:
the developing roller according to claim 1 to bear a developer including a toner on a surface thereof to supply the developer to a latent image bearing member;
a developer container to contain the developer;
a developer supplying member to supply the developer in the developer container to a surface of the developing roller; and
a developer regulating member to form a layer of the developer on the developing roller.

8. A process cartridge comprising:
a latent image bearing member to bear an electrostatic latent image on a surface thereof; and
the developing device according to claim 7 to develop the electrostatic latent image on the surface of the latent image bearing member with a developer including a toner to form a toner image on the surface of the latent image bearing member,
wherein the latent image bearing member and the developing device are integrated as a unit.

9. An image forming apparatus comprising:
a latent image bearing member to bear an electrostatic latent image on a surface thereof;
a charger to charge the surface of the latent image bearing member;
an irradiator to irradiate the charged surface of the latent image bearing member with light based on image data to form the electrostatic latent image on the surface of the latent image bearing member;
the developing device according to claim 7 to develop the electrostatic latent mage with a developer including a toner to form a toner image on the surface of the latent image bearing member;
a transferring device to transfer the toner image onto a recording medium; and
a fixing device to fix the toner image to the recording medium.

10. An image forming method comprising:
charging a surface of a latent image bearing member;
irradiating the charged surface of the latent image bearing member with light based on image data to form an electrostatic latent image on the surface of the latent image bearing member;
forming a developer layer with a predetermined thickness on the developing roller according to claim 1 ;
developing the electrostatic latent image with the developer layer on the developing roller to form a toner image on the surface of the latent image bearing member;
transferring the toner image onto a recording medium; and
fixing the toner image to the recording medium.

Assignees

• Juri Keiichiro
• Yasunaga Hideaki
• Nozaki Chiyoshi
• Ricoh Co Ltd

Inventors

• Juri Keiichiro
• Yasunaga Hideaki
• Nozaki Chiyoshi

Classifications

• G03G15/0818 Primary

  characterised by the structure of the donor member, e.g. surface properties · CPC title