Abstract: A copolymer obtained by copolymerizing at least one monomer selected from specific acrylate or methacrylate monomers, at least one monomer selected from specific amino group-containing monomers and at least one monomer selected from specific polar group-containing monomers. A resin for electrophotographic functional component parts, which contains this copolymer, a developing roller in which a cover layer serving as a surface layer contains the copolymer as a positive charge control resin, and an electrophotographic apparatus that includes the developing roller.

Abstract: To provide a positive charge control resin with which an electrophotographic functional component part coming into contact with a toner can be made chargeable in a polarity reverse to the polarity of the toner, and which has superior dispersibility in, and compatibility with, a main binder. The present invention is a positive charge control resin having a copolymer obtained by polymerizing specific acrylate or methacrylate monomer, amino-group-containing monomer(s) and carboxyl-group-containing monomer(s) as copolymerization components.

Abstract: A copolymer obtained by copolymerizing at least one monomer selected from specific acrylate or methacrylate monomers, at least one monomer selected from specific amino group-containing monomers and at least one monomer selected from specific polar group-containing monomers. A resin for electrophotographic functional component parts, which contains this copolymer, a developing roller in which a cover layer serving as a surface layer contains the copolymer as a positive charge control resin, and an electrophotographic apparatus that includes the developing roller.

Abstract: To provide a positive charge control resin with which an electrophotographic functional component part coming into contact with a toner can be made chargeable in a polarity reverse to the polarity of the toner, and which has superior dispersibility in, and compatibility with, a main binder. The present invention is a positive charge control resin having a copolymer obtained by polymerizing specific acrylate or methacrylate monomer, amino-group-containing monomer(s) and carboxyl-group-containing monomer(s) as copolymerization components.

Abstract: A negative-chargeability control resin containing a specific vinyl copolymer imparts stable chargeability to toner. The vinyl copolymer is obtainable by copolymerizing a monomer composition which contains at least i) a vinyl monomer (A) as exemplified by N-acryloylmorpholine, N-isopropylacrylamide, N-methylmethacrylamide, N-butoxymethylacrylamide or N-t-butylacrylamide, or a vinyl monomer (B) as exemplified by vinyl butyrate, vinyl 2-ethylhexanoate, vinyl benzoate, vinyl monochloroacetate pivarate, and ii) a vinyl monomer (C) having as a functional group a carboxyl group or a carboxyl group made into salt structure.

Abstract: A negative-chargeability control resin containing a specific vinyl copolymer imparts stable chargeability to toner. The vinyl copolymer is obtainable by copolymerizing a monomer composition which contains at least i) a vinyl monomer (A) as exemplified by N-acryloylmorpholine, N-isopropylacrylamide, N-methylmethacrylamide, N-butoxymethylacrylamide or N-t-butylacrylamide, or a vinyl monomer (B) as exemplified by vinyl butyrate, vinyl 2-ethylhexanoate, vinyl benzoate, vinyl monochloroacetate pivarate, and ii) a vinyl monomer (C) having as a functional group a carboxyl group or a carboxyl group made into salt structure.

Abstract: A semiconducting member has a water-soluble polyaniline having an acidic group, and an aqueous polymeric compound. The semiconducting member has a volume resistivity of from 104 &OHgr;·cm to 1012 &OHgr;·cm.

Abstract: Fluorine-containing polyfunctional (meth)acrylate represented by the formula (1), a monomer composition containing the (meth)acrylate, a low refractivity material prepared by curing the monomer composition, and a reflection reducing film provided with the low refractivity material. wherein R1, R2, R3, and R4 are the same or different groups, and each stands for a hydrogen atom, an acryloyl group, or a methacryloyl group, at least one of R1 and R2 and at least one of R3 and R4 stand for an acryloyl group or a methacryloyl group, R stands for a fluoroalkylene group having 2 to 12 carbon atoms and 2 or more fluorine atoms.

Abstract: Fluorine-containing polyfunctional (meth)acrylate represented by the formula (1), as well as a composition, a low refractivity material and a reflection reducing film in which the (meth)acrylate is utilized: ##STR1## wherein X stands for a fluoroalkyl group of C1-14 having 3 or more F, or a fluorocycloalkyl group of C3-14 having 4 or more F; Y.sup.1, Y.sup.2, and Y.sup.3 stand for H, an acryloyl group or a methacryloyl group, and at least two of Y.sup.1, Y.sup.2, and Y.sup.3 stand for an acryloyl group or a methacryloyl group; Z stands for H or an alkyl group of C1-3; and n and m is an integer of 0 or 1, and n+m=1.