Lexmark International, Inc.

Edward Wayne Weidert

Ronald Lloyd Roe

Johnny Dale Massie, Ii

Scott Daniel Reeves

Roger Nicholas Thompson

Angela Rachele Perruzza

A polyurethane-silica hybrid, or polyurethane-silica/silsesquioxane hybrid overcoat improves the life of the photoconductor drum without significantly altering the electrophotographic properties of the PC drum. Wear can be caused by a variety of factors, which include contact with the cleaner blade, paper, or intermediate transfer member or by erosion or scratching from toner components. The combination of hard and soft segments allows for a tough, wear resistant material with the added flexibility to prevent erosion from toner particles that are swept along the surface of the drum by the cleaner blade. A benzophenone ultraviolet absorber chemically linked to the silsesquioxane appears to inhibit room light fatigue and improve the electrostatic cycling of the PC drum. The overcoat also inhibits crazing.

Photoconductor with ceramer overcoat

Inserts ( ) to reduce noise from photoconductor drums during use are molded by thermal injection to have a bridge ( ) across the longitudinal gap ( ) of the insert. In the preferred embodiment the bridge is centered with respect to the long dimension of the insert and the bridge is in the form of a rectangle and thin. The bridge holds the shape of the insert during cooling after molding. Subsequently, the bridge may be severed or cut out, but that is generally unnecessary.

Fabrication of photoconductor drum insert

A roller for electrophotography is made from a mixture of polyurethane, polydiene, polyether diol, a first conductive filler and a second conductive filler which catalyzes oxidation of the polydiene. The first conductive filler comprises hexahalogenated acetylacetonates. The roller has a very high outer surface electrical resistance from baking the roller to oxidize the polybutadiene. The charge roller is achieved at low production cost and functions well with charging by a DC potential and AC overlay.

Polyurethane roller with high surface resistance

A charge roller made from a mixture of urethane, polybutadiene, a polyether diol, ferric chloride, and antimony doped tin oxide with or without carbon black. The roller has a very high outer surface electrical resistance from baking the roller to oxidize the polybutadiene. The charge roller is achieved at low production cost and functions well even with charging by a DC potential with an AC overlay.

A primary charge roller configuration with an annular lip protruding from the roll core prevents wear of the roller edges into the photoconductive drum. The gap between the lip and the shaft created by the lip can be void or can be filled with a soft material, such as EPDM or SBR.

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Superior, CO, United States of America

Edward Wayne Weidert