Patent ID: 8354164

Claim:
A developing roll for developing an electrostatic latent image into a toner image, comprising: a core shaft; and a surface layer comprising a semiconductive member on a surface of the core shaft, the semiconductive member comprising an alkali metal salt having the following formula (1) in a surface layer thereof: (M) n .X (1) wherein: M represents a member selected from the group consisting of Na + , K + , and Li + ; X represents a member selected from the group consisting of Cl − , Br − , I − , F − , CH 3 COO − , CF 3 COO − , CH(COOH)CHCOO − , (CHCOO − ) 2 , CH 2 (COOH)CH 2 COO − , (CH 2 COO − ) 2 , (HOOC)Ar(COO − ), Ar(COO − ) 2 , (HOOC) 2 Ar(COO − ), (HOOC)Ar(COO − ) 2 , Ar(COO − ) 3 , (HOOC) 3 Ar(COO − ), (HOOC) 2 Ar(COO − ) 2 , (HOOC)Ar(COO − ) 3 , Ar(COO − ) 4 , Ar—SO 3 − , Ar(SO 3 −) 2 , an oligomer or a polymer having an acrylic acid anion unit, and an oligomer or a polymer having an methacrylic acid anion unit; Ar represents a member selected from the group consisting of a benzene ring, a naphthalene ring, and a biphenyl ring; n is a numeral equivalent to the anionic valence of X; fine particles having an average particle diameter of from 0.05 to 1.0 μm are fixed on a surface of the developing roll; the fine particles are fine particles of a carbon black; and the carbon black comprises at least one of an alkali metal salt of a carboxylic acid and an alkali metal salt of a sulfonic acid on a surface thereof.