Abstract: There is provided a charging member cleaning roller including: a core body; and an elastic layer that is provided on a peripheral surface of the core body and includes a polyurethane foam obtained from at least a polyester polyol, a foam stabilizer, and a catalyst. Moreover, there is provided a charging member cleaning roller including: a core body; and an elastic layer that is provided on a peripheral surface of the core body and includes a urethane foam having an open-cell structure, a resilience of approximately 15% to 30%, and a hardness of approximately 150N to 230N.

Abstract: A toner for electrophotography contains a binder resin and a coloring agent, and is characterized in that the binder resin contains a crystalline polyester resin, and a low-molecular compound having at least one of a naphthalene skeleton and a biphenyl skeleton, and the crystalline polyester resin contains 0.5 to 30 construction mole % of an aromatic dicarboxylic acid-derived constitutional component. Further, a developer for electrophotography and an image forming method using the toner for electrophotography are disclosed.

Abstract: There is provided a charging member cleaning roller including: a core body; and an elastic layer that is provided on a peripheral surface of the core body and includes a polyurethane foam obtained from at least a polyester polyol, a foam stabilizer, and a catalyst. Moreover, there is provided a charging member cleaning roller including: a core body; and an elastic layer that is provided on a peripheral surface of the core body and includes a urethane foam having an open-cell structure, a resilience of approximately 15% to 30%, and a hardness of approximately 150N to 230N.

Abstract: A toner for electrophotography contains a binder resin and a coloring agent, and is characterized in that the binder resin contains a crystalline polyester resin, and a low-molecular compound having at least one of a naphthalene skeleton and a biphenyl skeleton, and the crystalline polyester resin contains 0.5 to 30 construction mole % of an aromatic dicarboxylic acid-derived constitutional component. Further, a developer for electrophotography and an image forming method using the toner for electrophotography are disclosed.

Abstract: A novel titanyl phthalocyanine crystal, a photoconductive material comprising the same, and an electrophotographic photoreceptor using the same are disclosed. The titanyl phthalocyanine crystal has a primary particle diameter ranging from 0.03 to 0.15 &mgr;m, shows a maximum X-ray diffraction peak at a Bragg angle (2&thgr;±0.2°) of 27.3°, has a ellipsoidal tabular form, and has a BET specific surface area of not less than 35 m2/g. The crystal has improved crystal form stability against solvents and holds its crystal form for an extended period of time in a dispersed and coated state. An electrophotographic photoreceptor using the crystal as a photoconductive material is excellent in sensitivity, stability, and durability.

Abstract: An electrophotographic photoreceptor comprising an electrically-conductive substrate having thereon at least a photosensitive layer and a surface protective layer: wherein the surface protective layer has a network structure formed by the reaction of hydroxyl group-containing compounds with an isocyanate group-containing compound; and wherein at least one of the hydroxyl group-containing compounds is an electric charge-transporting material containing a hydroxyl group. Also disclosed are a preparation process of the electrophotographic photoreceptor and an image forming apparatus comprising the electrophotographic photoreceptor.

Abstract: An electrophotographic photoreceptor excellent in wear resistance and low in residual potential comprising a conductive support, and a photoconductive layer and a protective layer formed on the conductive support. The protective layer contains a finely divided metal oxide powder and a binder resin composed of a polymer containing an acrylate or a methacrylate having at least one silicon-containing functional group as a monomer component, the polymer being crosslinked with said silicon-containing functional group. Also disclosed is an image forming method using the electrophotographic photoreceptor.

Abstract: An improved electrophotographic photosensitive material having a photosensitive layer on a conductive support.

Abstract: In a method for making an image comprising the steps of forming an electrostatic image on a photosensitive body having a photosensitive layer and forming a visible image by means of a liquid development utilizing a developing liquid for electrostatic charge, the photosensitive layer comprises, as an electric charge transporting material, an electric charge transporting polymeric compound which contains as a partial moiety of repeating units the structures represented by the following general formulas 1-1 and/or 1-2, ##STR1## where R.sub.1 -R.sub.4 are each independently hydrogen, an alkyl radical that may have a substituent, or the like, X is a substituted or unsubstituted divalent aryl radical, k and l are each an integer of 0 or 1, and T is a divalent hydrocarbon radical of 1-10 carbon atoms that may be branched.

Abstract: An organic electronic device comprises a layer containing a charge-transporting polyester comprising a repeating unit comprising at least one of partial structural units represented by the following formulae (I-a) and (I-b) as a partial structure of repeating unit: ##STR1## where the symbols in the above formulae are defined in the specification.

Abstract: In an electrophotographic process including an image forming process comprising a charging step of bringing a conductive charging member into contact with a surface of a photoreceptor and applying a superimposed voltage of a direct current voltage and an alternating current voltage to said conductive charging member to directly charge the surface of the photoreceptor, an image exposing step, and a developing step, the application of the voltage to said conductive charging member is stopped for every cycle of the image forming process, whereby the wear of the photoreceptive layer can be reduced and the life of the photoreceptor can be extremely improved.

Abstract: An electrophotographic photoreceptor is disclosed which comprises an electroconductive substrate and a photosensitive layer formed thereon, said photosensitive layer containing as a binder resin a copolycarbonate resin comprising a structural unit represented by formula (I) ##STR1## and a structural unit represented by formula (II) ##STR2## wherein X and X' each is hydrogen, a halogen, or methyl; R, a substituent, is hydroxyl, carboxyl, acetyl, or a C.sub.1-4 alkyl; and j is 0 to 3 and further containing as a charge transport material a triarylamine compound represented by formula (III) ##STR3## wherein R.sub.1 is hydrogen or methyl; k is 1 or 2; and Ar.sub.1 and Ar.sub.2 each is an optionally substituted aryl.

Abstract: An electrophotographic photoreceptor comprising a conductive substrate having provided thereon a photosensitive layer, wherein said photosensitive layer contains, as charge transporting material (i) at least one triarylamine compound represented by formula (I) ##STR1## wherein the definition of Ar.sub.1, Ar.sub.2 are described in the present specification; and (ii) at least one benzidine compound represented by formula (II) ##STR2## wherein the definition of R.sub.1, R.sub.1 ', R.sub.2, R.sub.2 ', R.sub.3, R.sub.3 ', m and n is described in the specification. The photoreceptor maintains its electrical characteristics stably on repeated use.

Abstract: A novel titanyl phthalocyanine crystal, a photoconductive material comprising the same, and an electrophotographic photoreceptor using the same are disclosed. The titanyl phthalocyanine crystal has a primary particle diameter ranging from 0.03 to 0.15 .mu.m, shows a maximum X-ray diffraction peak at a Bragg angle (2.theta..+-.0.2.degree.) of 27.3.degree., has a ellipsoidal tabular form, and has a BET specific surface area of not less than 35 m.sup.2 /g. The crystal has improved crystal form stability against solvents and holds its crystal form for an extended period of time in a dispersed and coated state. An electrophotographic photoreceptor using the crystal as a photoconductive material is excellent in sensitivity, stability, and durability.

Abstract: An electrophotographic photoreceptor comprising a conductive substrate having formed thereon a photosensitive layer containing at least a charge generating material, a charge transporting material, and a binder resin, wherein said charge transporting material comprises a benzidine compound and/or a low-molecular weight charge transporting material having a molecular weight of from 200 to 400 and said binder resin mainly comprises a polycarbonate resin comprising a recurring unit represented by formula (I): ##STR1## and having a viscosity-average molecular weight ranging from 50,000 and 100,000, said charge transporting material and said binder resin being at a weight ratio of from 25:75 to 60:40. The photoreceptor exhibits improved abrasion resistance and improved peeling resistance while retaining excellent electrical and image characteristics.

Abstract: Crystals of hydroxygallium phthalocyanine, a method of preparing the crystals, a photoconductive material containing the crystals, and an electrophotographic photoreceptor having the material. The photoreceptor has excellent electrophotographic characteristics. The crystals of hydroxygallium phthalocyanine have distinct diffraction peaks at (i) 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.3.degree., or (ii) 7.7.degree., 16.5.degree., 25.1.degree. and 26.6.degree., or (iii) 7.9.degree., 16.5.degree., 24.4.degree. and 27.6.degree., or (iv) 7.0.degree., 7.5.degree., 10.5.degree., 11.7.degree., 12.7.degree., 17.3.degree., 18.1.degree., 24.5.degree., 26.2.degree. and 27.1.degree., or (v) 6.8.degree., 12.8.degree., 15.8.degree. and 26.0.degree. or (vi) 7.4.degree., 9.9.degree., 25.0.degree., 26.0.degree., and 28.2.degree. of the Bragg angle (2.theta..+-.0.2) in the X-ray diffraction spectrum.

Abstract: An electrophotographic photoreceptor comprising a conductive substrate having formed thereon a photosensitive layer containing, as binder resins, (A) a polycarbonate resin comprising a recurring unit represented by formula (I): ##STR1## and (B) a polycarbonate resin comprising a recurring unit represented by formula (II) or (III): ##STR2## wherein X.sub.1 and X.sub.2 each represent a hydrogen atom or an alkyl group, or (B') a copolycarbonate resin comprising a recurring unit represented by formula (II) and a recurring unit represented by formula (IV): ##STR3## said polycarbonate resin (B) or copolycarbonate resin (B') having a lower molecular weight than that of said polycarbonate resin (A). The photoreceptor had high film strength against abrasion and causes no toner filming or adhesion of any other foreign substances and is therefore excellent in electric characteristics and image characteristics.

Abstract: An electrophotographic photoreceptor is disclosed, which comprises an electrically conductive substrate having thereon a charge generating layer and a charge transporting layer, said charge generating layer containing a resin binder and a charge generating material (selenium or an alloy of selenium), and said resin binder being a polyvinyl acetal resin and preferably a partially acetallized polyvinyl butyral resin. The electrophotographic photoreceptor according to the present invention has a photosensitivity which is less dependent on surface voltage.

Abstract: An electrophotographic photoreceptor is disclosed, which comprises an electrically conductive substrate having thereon a photosensitive layer comprising a resin binder in which the following two kinds of charge generating materials are dispersed: (i) selenium or an alloy of selenium and (ii) a phthalocyanine derivative represented by the formula: ##STR1## wherein M represents AlCl, Mg, VO, InCl or H.sub.2. The electrophotographic photoreceptor exhibits a broad spectral sensitivity extending from the visible to the infrared regions of the spectrum and, therefore, can be suited for printers which utilize such light sources as semiconductor lasers, light emitting diodes, etc.

Abstract: An electrophotographic photoreceptor is disclosed, comprising a light-sensitive layer on an electrically conductive substrate, wherein the light-sensitive layer comprises particles of selenium or a selenium alloy as the charge generating material, and at least one compound represented by formula (I), ##STR1## wherein R.sub.1 represents a hydrogen atom, an alkyl group or an alkoxyl group; R.sub.2 and R.sub.3, which may be the same or different, represent each a hydrogen atom, an alkyl group, an alkoxyl group, a halogen atom, an alkoxycarbonyl group or a substituted amino group; and at least one compound represented by formula (II), ##STR2## wherein R.sub.4, R.sub.5 and R.sub.6, which may be the same or different, represent each a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, an alkoxycarbonyl group or a substituted amino group, as the charge transporting materials.