Kyocera Mita Corporation

Kyocera Document Solutions Inc.

Mita Industrial Co., Ltd.

Yoshio Inagaki

Daisuke Kuboshima

Keiji Maruo

Kazunari Hamasaki

Tetsuya Ichiguchi

Jun Azuma

Eiichi Miyamoto

Hideki Okada

Yukimasa Watanabe

Hirofumi Kawaguchi

Junichiro Otsubo

Norio Nakai

Fumio Sugai

Mikio Kakui

Akihiko Kawahara

Ayako Yashima

Hideaki Fukunaga

The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electrophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor. The oxo-titanylphthalocyanine crystal has predetermined optical characteristics and thermal properties and is produced by a production method including the following steps (a) to (d): (a) a step of dissolving a crude oxo-titanylphthalocyanine crystal in an acid to obtain an oxo-titanylphthalocyanine solution; (b) a step of adding the oxo-titanylphthalocyanine solution dropwise in a poor solvent to obtain a wet cake; (c) a step of washing the wet cake with an alcohol having 1 to 4 carbon atoms; and (d) a step of stirring the washed wet cake under heating in a nonaqueous solvent to obtain an oxo-titanylphthalocyanine crystal.

Oxo-titanylphthalocyanine crystal, method for producing the same and electrophotographic photoreceptor

The present invention provides an electrophotographic photoreceptor comprising a photosensitive layer that contains at least a charge generating agent, a hole transport agent and a prede mulas (A) and (B). The electrophotographic photoreceptor prevents image defect termined additive. The hole transport agent satisfies the following for from occurring and can meet the demand for higher speed image forming apparatuses, by reducing the adhesion of paper dust and preventing the occurrence of cracks. 

Electrophotographic photoreceptor and image forming apparatus

Oxo-titanylphthalocyanine crystal, method for producing the same, and electrophotographic photoreceptor

An electrophotographic photoconductor having an excellent crack resistance and wear resistance as well as excellent sensitivity characteristics, while keeping good image characteristics of the photoconductor is provided. In addition, an image-forming apparatus equipped with such an electrophotographic photoconductor is also provided. The electrophotographic photoconductor includes a photosensitive layer containing at least a charge-generating agent, a hole-transfer agent, and a binder resin on a conductive substrate. The hole-transfer agent has a solubility of 5 to 35% by weight with respect to triglyceride oleate and the photosensitive layer contains a compound represented by the following general formula (1) as an additive: 

Electrophotographic photoconductor and image-forming apparatus

A stilbene derivative compound having a specific substituent at the specific position thereof to exert good compatibility with a binder resin and to tend to be uniformly dispersed in a photoconductive layer so as to allow prolonged specified sensitive property, a process for the production thereof, and an electrophotographic photoconductor containing the stilbene derivative compound are provided. For preparing a stilbene derivative compound represented by the general formula (1), a specified formylated triphenylamine derivative compound and a specified diphosphate ester derivative compound are allowed to be reacted with each other in the presence of a catalyst. (wherein 'A' is a divalent organic group having aromatic hydrocarbon as a basic skeleton, each of the plural Rto Ris a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or the like, each of the plural Arand Aris a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, each of repeating numbers a and b is an integer of 0 to 4, and c is an integer of 1 to 3.)

Stilbene derivative compound, process for producing the same, and electrophotographic photoconductor

Stilbeneamine derivative and electrophotosensitive material using the same

Electrophotosensitive material

The present invention relates to a novel stilbene derivative, which is a stilbene compound wherein molecular structures of triphenylamino groups located at both sides of a benzene ring in a molecular center are unsymmetric, and an electrophotosensitive material having high sensitivity and improved repeatability, comprising a conductive substrate and a photosensitive layer formed on the substrate, the photosensitive layer containing the derivative.

Stilbene derivative, method of producing the same, and electrophotosensitive material using the same

Electrophotographic photoreceptor

The present invention provides a novel stilbene derivative represented by the general formula (1): ##STR1## wherein R.sup.1 and R.sup.3 represent an alkyl group, an aryl group, an aralkyl group or an alkoxy group which are optionally substituted; and R.sup.2 and R.sup.4 represent a hydrogen atom, an alkyl group or an alkoxy group which are optionally substituted, provided that when the substitution position of R.sup.2 and R.sup.4 is the 4-(para) position, R.sup.2 and R.sup.4 are hydrogen atoms, a method for producing the same and use thereof. The above stilbene derivative (1) is useful as an electric charge transferring material, particularly hole transferring material.

Stilbene derivative and method for producing the same

Growing community of inventors

Osaka, Japan

Yoshio Inagaki