Charging roll or developing roll for electrophotographic device

Patent metadata

Field	Value
Publication number	US-11215937-B2
Application number	US-202117226057-A
Country	US
Kind code	B2
Filing date	Apr 8, 2021
Priority date	Jul 30, 2019
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

An elastic body layer is composed of a conductive rubber composition containing an isoprene rubber, a rubber other than the isoprene rubber, and carbon black. The elastic body layer is phase-separated into a first rubber phase containing the isoprene rubber and a second rubber phase containing the rubber other than the isoprene rubber; in the range of a 5 μm×5 μm square of an arbitrary cross section of the elastic body layer, the area ratio of the first rubber phase is within a range of 10 to 90%. The resistance value of the elastic body layer is within a range of 1.0×103 to 1.0×106Ω. A surface layer contains an electronic conductive agent and a crosslinked body of at least one polyurethane resin of an ether polyurethane resin and a carbonate polyurethane resin, and the glass transition point of the surface layer is within a range of −10 to −70° C.

First claim

What is claimed is:

1. A charging roll for an electrophotographic device, comprising:
a shaft body, an elastic body layer formed on the outer periphery of the shaft body, and a surface layer formed on the outer periphery of the elastic body layer;
wherein the elastic body layer is composed of a conductive rubber composition containing an isoprene rubber, a rubber other than the isoprene rubber, and carbon black;
the elastic body layer is phase-separated into a first rubber phase containing the isoprene rubber and a second rubber phase containing the rubber other than the isoprene rubber, wherein the rubber other than the isoprene rubber is an acrylonitrile butadiene rubber; in the range of a 5 μm×5 μm square of an arbitrary cross section of the elastic body layer, the area ratio of the first rubber phase with respect to a total of the first rubber phase and the second rubber phase is within a range of 10 to 90%, the carbon black is eccentrically located in the second rubber phase than in the first rubber phase;
the resistance value of the elastic body layer is within a range of 1.0×10 3 to 1.0×10 6 Ω, a surface roughness Sa of the elastic body layer is 0.05 to 1.6 μm;
the surface layer contains an electronic conductive agent, an associative thickener and a crosslinked body of at least one polyurethane resin of an ether polyurethane resin and a carbonate polyurethane resin, and the glass transition point of the surface layer is within a range of −10 to −70° C., the polyurethane resin of the surface layer is an aqueous polyurethane resin, the associative thickener has a nonionic hydrophilic group and a hydrophobic group consisting of alkyl group, a content of the associated thickener in the composition constituting the surface layer is in a range of 0.5 to 10 parts by mass with respect to 100 parts by mass of the aqueous polyurethane resin,
the surface layer contains particles for roughness formation, a line roughness Rz at a portion of the surface layer containing the particles for roughness formation is 5.0 to 15.0 μm, and a product Sz·Sm of the surface roughness Sz and the line roughness Sm at a portion of the surface layer that does not contain the particles for roughness formation is 7.5 to 250 μm.

2. A developing roll for an electrophotographic device, comprising:
a shaft body, an elastic body layer formed on the outer periphery of the shaft body, and a surface layer formed on the outer periphery of the elastic body layer;
wherein the elastic body layer is composed of a conductive rubber composition containing an isoprene rubber, a rubber other than the isoprene rubber, and carbon black;
the elastic body layer is phase-separated into a first rubber phase containing the isoprene rubber and a second rubber phase containing the rubber other than the isoprene rubber, wherein the rubber other than the isoprene rubber is an acrylonitrile butadiene rubber; in the range of a 5 μm×5 μm square of an arbitrary cross section of the elastic body layer, the area ratio of the first rubber phase with respect to a total of the first rubber phase and the second rubber phase is within a range of 10 to 90%, the carbon black is eccentrically located in the second rubber phase than in the first rubber phase;
the resistance value of the elastic body layer is within a range of 1.0×10 3 to 1.0×10 6 Ω, a surface roughness Sa of the elastic body layer is 0.05 to 1.6 μm;
the surface layer contains an electronic conductive agent, an associative thickener and a crosslinked body of at least one polyurethane resin of an ether polyurethane resin and a carbonate polyurethane resin, and the glass transition point of the surface layer is within a range of −10 to −70° C., the polyurethane resin of the surface layer is an aqueous polyurethane resin, the associative thickener has a nonionic hydrophilic group and a hydrophobic group consisting of alkyl group, a content of the associated thickener in the composition constituting the surface layer is in a range of 0.5 to 10 parts by mass with respect to 100 parts by mass of the aqueous polyurethane resin,
the surface layer contains particles for roughness formation, a line roughness Rz at a portion of the surface layer containing the particles for roughness formation is 5.0 to 15.0 μm, and a product Sz·Sm of the surface roughness Sz and the line roughness Sm at a portion of the surface layer that does not contain the particles for roughness formation is 7.5 to 250 μm.

Assignees

• Sumitomo Riko Co Ltd

Inventors

• Nakazato Kenta
• MIYAGAWA Shimpei
• Horiuchi Takeru
• Akira Naoki
• Saito Takenori
• Saito Yoshihiro

Classifications

• G03G15/16

  of a toner pattern, e.g. a powder pattern {, e.g. magnetic transfer} · CPC title

• C09D109/00

  Coating compositions based on homopolymers or copolymers of conjugated diene hydrocarbons · CPC title

• G03G15/0216 Primary

  by bringing a charging member into contact with the member to be charged, e.g. roller, brush chargers · CPC title

• G03G15/0808

  characterised by the developer supplying means, e.g. structure of developer supply roller · CPC title

• F16C13/00

  Rolls, drums, discs, or the like (guide rollers in feeding webs B65H27/00; calender rolls, bearings therefor D21G1/02; rotary drums or rollers for heat-exchange or heat-transfer apparatus F28F5/02); Bearings or mountings therefor · CPC title