Kyocera Document Solutions Inc.

Kenji Kitaguchi

Jun Azuma

Tomofumi Shimizu

Keiji Maruo

Kensuke Okawa

Hideki Okada

Fumio Sugai

Kensuke Kojima

Akihiko Ogata

Seiki Hasunuma

Kiichiro Oji

A polyarylate resin includes repeating units (1), (2), and (4). The polyarylate resin further includes a repeating unit (3) and a percentage of the number of repeats of the repeating unit (3) relative to the total number of repeats of each of the repeating units (1) and (3) is greater than 0% and less than 50%. Alternatively, the polyarylate resin does not include the repeating unit (3).

Polyarylate resin and electrophotographic photosensitive member

A polyarylate resin includes repeating units represented by formulas (1), (2), (3), and (4). A third percentage is greater than 0% and less than 50%. The third percentage is a percentage of the number of repeats of the repeating unit represented by formula (3) relative to the total of the number of repeats of the repeating unit represented by formula (1) and the number of repeats of the repeating unit represented by formula (3). A fourth percentage is at least 35% and less than 70%. The fourth percentage is a percentage of the number of repeats of the repeating unit represented by formula (4) relative to the total of the number of repeats of the repeating unit represented by formula (2) and the number of repeats of the repeating unit represented by formula (4).

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), 

Production method for electrophotographic photosensitive member

A polyarylate resin includes at least one type of repeating unit represented by a general formula (1), at least one type of repeating unit represented by a general formula (2), and a terminal group represented by a general formula (3). R, R, R, and Reach represent, independently of one another, a hydrogen atom or a methyl group. Rand Reach represent, independently of each other, a hydrogen atom or a Calkyl group. Rand Rmay bond together to represent a Ccycloalkylidene group. Xrepresents a divalent group represented by a chemical formula (2A), (2B), (2C), or (2D) with the proviso that when only one type of repeating unit represented by the general formula (2) is included, Xdoes not represent a divalent group represented by the chemical formula (2D). Rrepresents a chain aliphatic group having at least one fluoro group. 

A polyarylate resin is represented by general formula (1) shown below. In general formula (1), Rand Reach represent, independently of one another, a hydrogen atom or a methyl group. r and s each represent an integer of at least 0 and no greater than 49. t and u each represent an integer of at least 1 and no greater than 50. r+s+t+u=100. r+t=s+u. X and Y each represent, independently of one another, a divalent group represented by chemical formula (1-1), chemical formula (1-2), chemical formula (1-3), or chemical formula (1-4). X and Y are different from one another. 

A triphenylamine derivative is represented by General Formula (1). In General Formula (1), ORrepresents an alkoxy group having 2 to 8 carbon atoms. Rto Reach independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Arand Areach independently represent a hydrogen atom, an aryl group having 6 to 20 carbon atoms and optionally substituted with an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 20 carbon atoms and optionally substituted with an alkoxy group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or a 3- to 10-membered heterocyclic group. Note that the case where Arand Arare both a hydrogen atom is excluded.

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Kenji Kitaguchi