ELECTROPHOTOGRAPHIC PHOTOCONDUCTOR, ELECTROPHOTOGRAPHIC PROCESS CARTRIDGE INCORPORATING THE SAME, AND IMAGE FORMING APPARATUS INCORPORATING THE SAME

• US 20080199217A1
• Filed: 02/21/2008
• Published: 08/21/2008
• Est. Priority Date: 02/21/2007
• Status: Abandoned Application

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Ikuno, Hiroshi, Fujiwara, Yukio, Kami, Hidetoshi, Suzuki, Tetsuro, Tamura, Hiroshi, IWAMOTO, Takafumi
• Application Number:
  US12/035,016
• Publication Number:
  US 20080199217A1
• Time in Patent Office: Days
• US Class Current: 399/159
• CPC Class Codes: G03G 5/0764 triarylamine
• CPC Class Codes: G03G 5/0766 benzidine
• CPC Class Codes: G03G 5/14704 comprising inorganic material
• CPC Class Codes: G03G 5/14708 comprising organic material
• CPC Class Codes: G03G 5/14786 Macromolecular compounds characterised by specific side-chain substituents or end groups
• 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
• CPC Class Codes: G03G 5/14795 Macromolecular compounds characterised by their physical properties

Abstract

An object is to provide an electrophotographic photoconductor which prevents an increase in the friction coefficient of the photoconductor surface caused when printing takes place for a long period of time or in large amounts, which has sustainability of the low photoconductor surface friction coefficient, low wear properties and high durability, and which is particularly superior in polymerized toner (or spherical toner) cleaning capability; a process cartridge incorporating the electrophotographic photoconductor; and an image forming apparatus incorporating the electrophotographic photoconductor. There is an electrophotographic photoconductor including: a photoconductor substrate, a photosensitive layer over the photoconductor substrate, and a protective layer over the photoconductor substrate, wherein the protective layer is formed by curing together at least a trifunctional or more radical polymerizable monomer having no charge transporting structure, a fluorine-based UV-curable hard coat agent and a monofunctional radical polymerizable compound having a charge transporting structure, and contains lubricant fine particles.

Claims

1. An electrophotographic photoconductor comprising:

a photoconductor substrate,

a photosensitive layer over the photoconductor substrate, and

a protective layer over the photoconductor substrate,

wherein the protective layer is formed by curing together at least a trifunctional or more radical polymerizable monomer having no charge transporting structure, a fluorine-based UV-curable hard coat agent and a monofunctional radical polymerizable compound having a charge transporting structure, and contains lubricant fine particles.

2. The electrophotographic photoconductor according to claim 1, wherein the lubricant fine particles contain at least one selected from fluorine resin fine particles, a silicone compound and polyethylene wax.

3. The electrophotographic photoconductor according to claim 1, wherein the fluorine-based UV-curable hard coat agent has a urethane bond in its molecule.

4. The electrophotographic photoconductor according to claim 1, wherein the content of the fluorine-based UV-curable hard coat agent and the lubricant fine particles in the protective layer is equal to or greater than 5% by mass and less than 60% by mass with respect to the total weight of the protective layer, and the fluorine-based UV-curable hard coat agent and the lubricant fine particles are mixed together with a mass ratio of 3:

7 to 7;

3.

5. The electrophotographic photoconductor according to claim 1, wherein the monofunctional radical polymerizable compound having a charge transporting structure is represented by the following structural formula.

where R₁ denotes a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, an aralkyl group that may have a substituent, an aryl group that may have a substituent, a cyano group, a nitro group, an alkoxy group, a —

COOR₇ group (R₇ denotes a hydrogen atom, an alkyl group that may have a substituent, an aralkyl group that may have a substituent, or an aryl group that may have a substituent), a carbonyl halide group or a —

CONR₈R₉ group (R₈ and R₉ each denote a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, an aralkyl group that may have a substituent, or an aryl group that may have a substituent, and they may be identical or different from each other);

Ar₁ and Ar₂ each denote a substituted or unsubstituted arylene group, and they may be identical or different from each other;

Ar₃ and Ar₄ each denote a substituted or unsubstituted aryl group, and they may be identical or different from each other;

X denotes a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom or a vinylene group;

Z denotes a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether divalent group, or an alkyleneoxycarbonyl divalent group; and

“

m”

denotes an integer of 0 to 3.

6. The electrophotographic photoconductor according to claim 1, wherein the components of the protective layer are cured by any one of heating and irradiation with light energy.

7. A process cartridge for an image forming apparatus, comprising:

an electrophotographic photoconductor, and

at least one selected from the group consisting of a charging unit, a developing unit, a transfer unit, a cleaning unit and a charge-eliminating unit,

wherein the electrophotographic photoconductor includes a photoconductor substrate, a photosensitive layer over the photoconductor substrate, and a protective layer over the photoconductor substrate; and

the protective layer is formed by curing together at least a trifunctional or more radical polymerizable monomer having no charge transporting structure, a fluorine-based UV-curable hard coat agent and a monofunctional radical polymerizable compound having a charge transporting structure, and contains lubricant fine particles, and wherein the process cartridge is detachably mountable to an image forming apparatus main body.

8. An image forming apparatus comprising:

any one of an electrophotographic photoconductor, and

a process cartridge,

wherein the electrophotographic photoconductor includes a photoconductor substrate, a photosensitive layer over the photoconductor substrate, and a protective layer over the photoconductor substrate;

the protective layer is formed by curing together at least a trifunctional or more radical polymerizable monomer having no charge transporting structure, a fluorine-based UV-curable hard coat agent and a monofunctional radical polymerizable compound having a charge transporting structure, and contains lubricant fine particles; and

the process cartridge includes the electrophotographic photoconductor, and one or more selected from the group consisting of a charging unit, a developing unit, a transfer unit, a cleaning unit and a charge-eliminating unit.