G03G5/061443

Method of producing an electrophotographic photoreceptor

A method of producing an electrophotographic photoreceptor composed of a photosensitive layer provided on a conductive substrate, includes, in the formation of an outermost layer, controlling slope k of a straight line obtained by plotting the average film density of outermost layer and boiling point of solvent used for the formation of the outermost layer along the ordinate and the abscissa, respectively, to be 1.50E-4 (g/cm.sup.3.Math. C.) or greater, and adjusting the difference in film density of the outermost layer between the surface side and the side close to the conductive substrate to be 0.030 g/cm.sup.3 or less. The electrophotographic photoreceptor has reduced image defects even after long-term use and has excellent wear performance.

Electrophotographic photosensitive member, process cartridge, and image forming apparatus

An electrophotographic photosensitive member (1) includes a conductive substrate (2) and a photosensitive layer (3). The photosensitive layer (3) is a single-layer photosensitive layer containing at least a charge generating material, an electron transport material, a hole transport material, and a binder resin. The electron transport material includes a naphthoquinone derivative represented by general formula (1). An amount of triboelectric charge of calcium carbonate as measured by charging the calcium carbonate through friction with the photosensitive layer (3) is at least +7 C/g. In general formula (1), R.sup.11 and R.sup.12 are respectively the same as R.sup.11 and R.sup.12 described in the description. ##STR00001##

PHOTOSENSITIVE BODY FOR ELECTROPHOTOGRAPHY, METHOD FOR PRODUCING THE SAME, AND ELECTROPHOTOGRAPHIC DEVICE INCLUDING THE SAME

The present invention provides an electrophotographic photoreceptor including a photosensitive layer containing an electron transport material, and having high pressure resistance and suppressed occurrence of a leak phenomenon, a method for producing the same, and an electrophotographic device using the same. The electrophotographic photoreceptor includes an electrically conductive support containing an aluminum alloy; an anodic oxide film formed on a surface of the electrically conductive support; and a photosensitive layer formed on the anodic oxide film. The photosensitive layer contains an electron transport material having an electron mobility of 10.sup.7 cm.sup.2/V/sec or more when field intensity is set to 20 V/m. The surface of the electrically conductive support having the anodic oxide film formed thereon has an admittance value that is 25 S or more and 60 S or less.

POSITIVE CHARGING ELECTROPHOTOGRAPHIC PHOTORECEPTOR, ELECTROPHOTOGRAPHIC CARTRIDGE AND IMAGE FORMING APPARATUS
20190384189 · 2019-12-19 · ·

The object of the present invention is to provide a positive charging electrophotographic photoreceptor having high sensitivity, low residual potential, and excellent chargeability, and relates to a positive charging electrophotographic photoreceptor including a conductive support, a photosensitive layer, and a protective layer in this order, the photosensitive layer containing a charge generation substance, a positive hole transport substance, and an electron transport substance in the same layer, in which the positive hole transport substance includes at least one of the compounds represented by any one of the following formulas (1) to (5), and a binder resin of the protective layer is an alcohol-soluble thermoplastic resin, providing that the symbols in the formula are defined in the specification.

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Polyarylate resin and electrophotographic photosensitive member
10509309 · 2019-12-17 · ·

A polyarylate resin is represented by general formula (1) shown below. In general formula (1), R.sup.1 represents a hydrogen atom or methyl group. R.sup.2 and R.sup.3 each represent a hydrogen atom or an alkyl group having a carbon number of at least 1 and no greater than 4. R.sup.2 and R.sup.3 are not the same as one another. When R.sup.1 represents a hydrogen atom, R.sup.2 and R.sup.3 are not bonded to one another. When R.sup.1 represents a methyl group, R.sup.2 and R.sup.3 are optionally bonded to one another to form a ring. r and s each represent a number greater than or equal to 0 and less than or equal to 49. t and u each represent a number greater than or equal to 1 and less than or equal to 50. r+s+t+u=100. r+t=s+u. ##STR00001##

ELECTROPHOTOGRAPHIC PHOTORECEPTOR, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

An electrophotographic photoreceptor includes a conductive substrate, and a lamination type photosensitive layer including a charge generation layer and a charge transport layer or a single layer type photosensitive layer that is a photosensitive layer disposed on the conductive substrate, in which the charge transport layer or the single layer type photosensitive layer is an outermost layer and contains a charge transport material and a binder resin containing a polyester resin having an aromatic ring, the charge transport layer or the single layer type photosensitive layer has an average thickness of 28 ?m or greater and 50 ?m or less, and a weight reduction ratio of the charge transport layer or the single layer type photosensitive layer from 30? C. to 175? C. in thermogravimetric analysis is 0.1% by mass or less.

Electrophotographic photosensitive member, process cartridge, and image forming apparatus
10509337 · 2019-12-17 · ·

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer having a single-layer structure. The photosensitive layer contains a charge generating material, an electron transport material, a polycarbonate resin, and a hole transport material. The electron transport material includes a compound having a halogen atom and represented by general formula (1), (2), (3), (4), or (5). The hole transport material includes a compound represented by general formula (20), (21), (22), (23), (24), (25), (26), or (27). A charge of calcium carbonate as measured by charging the calcium carbonate through friction with the photosensitive layer is at least +6.5 C/g. A Vickers hardness of the photosensitive layer at 45 C. is at least 17.0 HV. ##STR00001## ##STR00002## ##STR00003##

ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER AND METHOD FOR PRODUCING ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER

A method for producing an electrophotographic photosensitive member having a photosensitive layer and a protective layer above a support in this order includes: forming a coating film for a protective layer by coating a coating liquid for the protective layer for forming the protective layer on the photosensitive layer and curing the coating film for the protective layer, in which the coating liquid for the protective layer contains a solvent, a compound represented by a general formula (1), a compound represented by a general formula (2), and a compound represented by a general formula (3) at a specific ratio. In addition, in an electrophotographic photosensitive member having a photosensitive layer and a protective layer above a support in this order, the protective layer is obtained by curing a coating liquid for the protective layer.

PRODUCTION METHOD FOR ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER

A method for producing an electrophotographic photosensitive member includes an electrically conductive substrate and a photosensitive layer. The method includes applying an application liquid for photosensitive layer formation containing a solvent, a binder resin, and a hole transport material directly or indirectly onto the electrically conductive substrate, and removing a portion of the solvent, to form the photosensitive layer. The solvent contains a first solvent that is an alcohol having a carbon number of at least 1 and no greater than 3, and a second solvent other than the first solvent. The binder resin includes a polyarylate resin that is a polymerization product of monomers including a first monomer represented by general formula (1) and a second monomer represented by general formula (2),

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Electrophotographic photosensitive member, process cartridge, and image forming apparatus

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single-layer photosensitive layer and contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The binder resin has a viscosity average molecular weight of at least 25,000 and no greater than 50,000. A strain at break of the photosensitive layer is at least 4.9% and no greater than 13.0%. A scratch resistant depth of the photosensitive layer is no greater than 0.50 m.