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Charging member, manufacturing method of charging member, electrophotographic apparatus, and process cartridge

  • US 10,558,136 B2
  • Filed: 04/02/2019
  • Issued: 02/11/2020
  • Est. Priority Date: 04/18/2018
  • Status: Active Grant
First Claim
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1. A charging member comprising:

  • an electro-conductive support; and

    an elastic layer,wherein the elastic layer is a surface layer of the charging member, and is constituted by a mono layer,the elastic layer includes domains and a matrix, the domains each containing carbon black and rubber, the matrix containing rubber and having an electrical resistance higher than that of the domains,an outer surface of the charging member is constituted by a surface of the matrix and surfaces of the domains, and the charging member has concave portions on the outer surface,the domains exist at bottom portions of the respective concave portions and are exposed to the outer surface of the charging member only at the bottom portions of the respective concave portions,the elastic layer has a volume resistivity of 1×

    105 Ω

    cm or more and 1×

    108 Ω

    cm or less, andwhen A1 is defined as a current value at the time of applying a direct current (DC) voltage of 80 V between the electro-conductive support and a cantilever of an atomic force microscope in contact with a surface of the matrix constituting the outer surface of the charging member and A2 is defined as a current value at the time of applying a DC voltage of 80 V between the electro-conductive support and a cantilever of an atomic force microscope in contact with surfaces of the respective domains constituting the outer surface of the charging member, A2 is 20 times or more of A1.

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