ELECTROPHOTOGRAPHIC PHOTOSENSITIVE BODY

• US 20090081569A1
• Filed: 03/15/2006
• Published: 03/26/2009
• Est. Priority Date: 03/16/2005
• Status: Active Grant

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Hikosaka, Takaaki, Miyamoto, Hideyuki
• Granted Patent: US 8,043,775 B2
• Time in Patent Office: Days
• US Class Current: 430/66
• CPC Class Codes: G03G 5/147 Cover layers
• CPC Class Codes: G03G 5/14704 comprising inorganic material
• CPC Class Codes: G03G 5/14708 comprising organic material
• 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

Provided is an electrophotographic photosensitive body having a photosensitive layer on a conductive base, in which at least the outermost layer thereof contains particles having a double structure composed of a core member and a shell member having a lager rubber hardness than the core member. The electrophotographic photosensitive body has excellent mechanical strength such as wear resistance, abrasion resistance, and scratch resistance as well as excellent electrophotographic characteristics such as cleaning property for a long time period.

Claims

1. An electrophotographic photosensitive body having a photosensitive layer on a conductive base, the electrophotographic photosensitive body being characterized in that at least an outermost layer of the electrophotographic photosensitive body contains particles each having a double structure composed of a core member and a shell member having a larger rubber hardness than that of the core member.

2. An electrophotographic photosensitive body according to claim 1, wherein the outermost layer contains the particles each having a double structure at a content of 1 to 30 mass % with respect to a total amount of a binder resin, and other functional materials or a material for a protective layer.

3. An electrophotographic photosensitive body according to claim 1, wherein the particles each having a double structure have an average particle diameter of 10 μ

m or less.

4. An electrophotographic photosensitive body according to claim 1, wherein the particles each having a double structure comprise particles each obtained by coating a rubber spherical particle with a resin, or microcapsules each including a fluid.

5. An electrophotographic photosensitive body according to claim 4, wherein a material for the rubber spherical particle comprises at least one kind selected from a natural rubber, a synthetic natural rubber, a styrene-butadiene rubber, a butadiene rubber, a butyl rubber, a chloroprene rubber, a nitrile rubber, an acrylic rubber, an epichlorohydrin rubber, a urethane rubber, a polysulfide rubber, a fluoro rubber, at least one kind of a rubber-like polymer obtained from a monomer mainly composed of an alkyl acrylate, an alkyl methacrylate, or dimethylsiloxane, and a silicone rubber, and the resin comprises at least one kind selected from a polystyrene resin, a polyvinyl chloride resin, a polyvinyl acetate resin, a vinyl chloride-vinyl acetate copolymer, a polyvinyl acetal resin, an alkyd resin, an acrylic resin, a polyacrylonitrile resin, a polycarbonate resin, a polyamide resin, a butyral resin, a polyester resin, a vinylidene chloride-vinyl chloride copolymer, a methacrylic resin, a styrene-butadiene copolymer, a vinylidene chloride-acrylonitrile copolymer, a vinyl acetate resin, a vinyl chloride-vinyl acetate-maleic anhydride copolymer, a silicone-alkyd resin, a phenol-formaldehyde resin, a styrene-alkyd resin, a melamine resin, a polyether resin, a benzoguanamine resin, an epoxy acrylate resin, a urethane acrylate resin, a poly-N-vinylcarbazole resin, a polyvinyl butyral resin, a polyvinyl formal resin, a polysulfone resin, casein, gelatin, a polyvinyl alcohol resin, ethylcellulose, nitrocellulose, carboxy-methylcellulose, a vinylidene chloride-based polymer latex, an acrylonitrile-butadiene copolymer, a vinyl toluene-styrene copolymer, a soybean oil-modified alkyd resin, a polystyrene nitrate resin, a polymethylstyrene resin, a polyisoprene resin, a polythiocarbonate resin, a polyarylate resin, a polyhaloarylate resin, a polyarylether resin, a polyvinyl acrylate resin, a polyester acrylate resin, and a silicone resin.

6. An electrophotographic photosensitive body according to claim 5, wherein the rubber spherical particle is made of a silicone rubber, and the resin comprises a silicone resin.

7. An electrophotographic photosensitive body according to claim 4, wherein the fluid comprises at least one kind selected from a mineral oil, a polyolefin, a polyalkylene glycol, a monoester, a diester, a polyol ester, a phosphate, a silicate, polyphenyl ether, a perfluoroalkyl ether, a fluorine-based oil, a silicone oil, a silicone gel, and water, and a shell member of each of the microcapsules comprises at least one kind selected from gum arabic, gelatin, collagen, casein, polyamino acid, agar, sodium alginate, carrageenan, konjakmannan, a dextran sulfate, ethylcellulose, nitrocellulose, carboxymethylcellulose, acetylcellulose, a formalin naphthalenesulfonate condensate, a polyamide resin, a polyurethane resin, a polyester resin, a polycarbonate resin, an alkyd resin, an amino resin, a silicone resin, a maleic anhydride-based copolymer, an acrylate-based copolymer, a methacrylate-based copolymer, a polyvinyl chloride resin, a polyvinylidene chloride resin, a polyethylene resin, a polystyrene resin, a polyvinyl acetal resin, a polyacrylamide resin, polyvinylbenzene sulfonate, a polyvinyl alcohol resin, a urea-formaldehyde resin, and a melamine-formaldehyde resin.

8. An electrophotographic photosensitive body according to claim 7, wherein the fluid comprises a mineral oil, and the shell member of each of the microcapsules comprises a melamine-formaldehyde resin.