Mita Industrial Co., Ltd.

Kyocera Document Solutions Inc.

Kyocera Mita Corporation

Daikin Industries, Ltd.

Eiichi Miyamoto

Hiroki Tsurumi

Yasufumi Mizuta

Yasuyuki Hanatani

Hiroaki Iwasaki

Hideo Nakamori

Jun Azuma

Fumio Sugai

Ichiro Yamazato

Yohei Yamamoto

Hideki Okada

Mikio Kakui

Yukimasa Watanabe

Nariaki Tanaka

Toshiyuki Fukami

Akihiko Kawahara

Maki Uchida

Yukikatsu Imanaka

Nariaki Muto

Tatsuo Maeda

Nariaki Mutou

Tooru Nakazawa

Yuji Tanaka

Keisuke Sumida

Tomofumi Shimizu

Kazunari Hamasaki

Sakae Saito

Hirofumi Kawaguchi

Kensuke Kojima

Takashi Terada

Daisuke Kuboshima

Yoshio Inagaki

Atsushi Fujii

Hiroaki Sakai

Akiyoshi Urano

Hisakazu Honma

Tadashi Sakuma

Tsuneo Oki

Takahiko Murata

Keiji Maruo

Susumu Hiroshima

Hiroyuki Hazama

Masaya Nishimura

Mitsuo Ihara

Mitsuji Tsujita

Ayako Yashima

Tetsuya Ichiguchi

Masaaki Yokoyama

Makoto Shishido

Yuka Nakamura

Masayuki Ishii

Takuji Terada

Norio Nakai

Hiroshi Mishima

Tohru Ueno

Shiho Okawa

Hideaki Fukunaga

Yasuhiro Yamaguchi

An electrophotographic photosensitive member () includes a conductive substrate () and a photosensitive layer (). The photosensitive layer () is a single-layer photosensitive layer. The photosensitive layer () contains at least a charge generating material, a hole transport material, an electron transport material, and a binder resin. The charge generating material includes a metal-free phthalocyanine. The hole transport material includes a triphenylamine derivative represented by general formula (1) shown below. The electron transport material includes a quinone derivative represented by general formula (2) shown below. In general formula (1), R, R, R, m1, m2, k, p, and q are the same as those described in the description. In general formula (2), R, R, and Rare the same as those described in the description. 

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. A hole mobility &#x3bc;is at least 1.00&#xd7;10cm/V/second and an electron mobility &#x3bc;is at least 4.00&#xd7;10cm/V/second in the photosensitive layer as measured under conditions of a temperature of 23&#xb0; C. and an electric field intensity of 1.50&#xd7;10V/cm. A ratio (&#x3bc;/&#x3bc;) of the hole mobility &#x3bc;to the electron mobility &#x3bc;is at least 1.0 and no greater than 50.0.

Electrophotographic photosensitive member

A photosensitive member () includes a conductive substrate () and a photosensitive layer (). The photosensitive layer is a single-layer photosensitive layer (). The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The hole transport material includes a triphenylamine derivative represented by general formula (HT). The electron transport material includes a compound represented by general formula (ET1), (ET2), (ET3), (ET4), or (ET5). The binder resin includes a polyarylate resin represented by general formula (1) 

A positively chargeable single-layer electrophotographic photosensitive member is used as an image bearing member in an image forming apparatus including a charging section configured to be in contact with the image bearing member to apply a voltage thereto. The positively chargeable single-layer electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer contains at least a charge generating material, a hole transport material, an electron transport material, and a binder resin. The hole transport material contains a triarylamine derivative represented by the following general formula (I). In general formula (I), R, R, m and n have the same meaning as R, R, m, and n defined in the description. 

Positively chargeable single-layer electrophotographic photosensitive member, process cartridge, and image forming apparatus

In a positively chargeable single-layer electrophotographic photosensitive member, a photosensitive layer contains at least a hole transport material, and particles of a first resin. A compound represented by general formula (1) is contained as the hole transport material. In the general formula (1), Rrepresents an alkyl group having a carbon number of at least 2 and no greater than 4. R, R, R, R, and Reach represent, independently of one another, a hydrogen atom or an alkyl group having a carbon number of at least 1 and no greater than 4. Arand Areach represent, independently of each other, a hydrogen atom or an optionally substituted aryl group having a carbon number of at least 6 and no greater than 20. At least one of Arand Arrepresents an optionally substituted aryl group having a carbon number of at least 6 and no greater than 20. 

A triarylamine derivative is represented by general formula (I). In general formula (I), Rand Reach represent, independently of one another, a chemical group selected from the group consisting of a halogen atom, an optionally substituted alkyl group having a carbon number of 1-6, an optionally substituted alkoxy group having a carbon number of 1-6, and an optionally substituted aryl group having a carbon number of 6-12. In general formula (I), k and l each represent an integer of at least 0 and no greater than 4. When k and l represent integers greater than 1, chemical groups Rbonded to the same aromatic ring and chemical groups Rbonded to the same aromatic ring may be the same or different to one another. In general formula (I), m and n each represent a different integer of at least 1 and no greater than 3. 

Triarylamine derivative, electrophotographic photosensitive member, and image forming apparatus

A triphenylamine derivative is represented by general formula (1). In general formula (1), Rto Reach represent, independently of one another, a chemical group selected from the group consisting of a halogen atom, an optionally substituted alkyl group having a carbon number of at least 1 and no greater than 6, an optionally substituted alkoxy group having a carbon number of at least 1 and no greater than 6, and an optionally substituted aryl group having a carbon number of at least 6 and no greater than 12. Also, k, l, m, n, o, and p each represent, independently of one another, an integer of at least 0 and no greater than 4. When any of k, l, m, n, o, or p represents an integer greater than 1, chemical groups R, R, R, R, or Rbonded to the same aromatic ring may be the same or different. 

Triphenylamine derivative, electrophotographic photosensitive member, and image forming apparatus

A positively chargeable single-layer electrophotographic photosensitive member includes a single-layer photosensitive layer. The single-layer photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The electron transport material contains two or more compounds selected from the group consisting of compounds represented by the chemical formulas (1) to (4) below. 

Positively chargeable single-layer electrophotographic photosensitive member and image forming apparatus

A positively chargeable monolayer electrophotographic photosensitive member includes a photosensitive layer provided on a conductive substrate and having a monolayer structure containing at least a charge generating material, a hole transport material, an electron transport material, and a binder resin. The photosensitive layer contains a hole transport material containing a triarylamine derivative represented by a formula (1) below and an electron transport material containing a compound selected from the group consisting of quinone compounds having a predetermined structure. 

Positively chargeable monolayer electrophotographic photosensitive member and image forming apparatus

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

An image forming apparatus which can exhibit an excellent charge eliminating effect by erasing a transfer memory using a precharging device with optimized conditions even when a positively-charged single-layer-type electrophotographic photoconductor is used as a photoconductor. In the image forming apparatus which sequentially arranges a charging device, a developing device, a transfer device, and a charge eliminating device around a single-layer-type electrophotographic photoconductor, the charging device charges a surface of the single-layer-type electrophotographic photoconductor with a positive polarity, a precharging device having a conductive member is arranged on an upstream side of the charge eliminating device, the conductive member is brought into contact with the electrophotographic photoconductor, and a current density I(&#x3bc;A/m) of the injected current into the photoconductor from the conductive member is set to a value of 700 (&#x3bc;A/m) or more.

Image forming device using a single-layer-type electrophotographic photoconductor and image forming method using the same

The present invention relates to a novel titanyl phthalocyanine crystal which can prepare a coating solution having excellent storage stability because it satisfies both of the following two characteristics (a) and (b), a method of producing the same, an electrophotosensitive material using the above crystal as an electric charge generating material.

Titanyl phthalocyanine crystal and production method of the same, and electrophotosensitive material

An electrophotographic photoreceptor is disclosed which includes a conductive resin substrate and a resin layer. The resin layer includes a binding resin and is formed on the conductive resin substrate. The difference between the solubility parameter of the conductive resin substrate and the solubility parameter of the resin layer of the photoreceptor is 2.5 (J/cm)or less.

Electrophotographic photoreceptor

Disclosed is a single-layer type electrophotosensitive material comprising a conductive substrate and a photosensitive layer made of a binder resin containing at least an electric charge generating material and an electric charge transferring material, which is formed on the conductive substrate, wherein an oxygen transmission rate of the binder resin is not more than 35 cc&middot;mm/m &middot;day&middot;atom, wherein it is preferred that a mobility at an electric field strength of 5&times;10 V/cm of the hole transferring material is not less than 5&times;10 cm /V/sec and a solid content of the electric charge transferring material is not less than 30% by weight and not more than 50% by weight based on the whole solid content; said electrophotosensitive material has good ozone resistance and does not cause defects such as image black belt due to lowering of the charge capability, an ozone of which is 5.0 ppm at most, and is also superior in sensitivity and wear resistance.

Single-layer type electrophotosensitive material

Electrophotosensitive material

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Osaka, Japan

Eiichi Miyamoto