Mita Industrial Co., Ltd.

Kyocera Mita Corporation

Masato Katsukawa

Masashi Tanaka

Toshiyuki Fukami

Hideo Nakamori

Ichiro Yamazato

Yuka Nakamura

Akiyoshi Urano

Mitsuo Ihara

Ayako Sugase

Yasufumi Mizuta

Hiroaki Iwasaki

Keizo Kimoto

Mitsuji Tsujita

Tatsuo Maeda

Satoru Miura

The present invention provides an electrophotosensitive material comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, the photosensitive layer comprising a specific hole transferring material and/or electron transferring material and a binding resin of a polyester resin which is a substantially linear polymer obtained by using a specific dihydroxy compound represented by the general formula (1):

Electrophotosensitive material

The present invention provides an electrophotosensitive material comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, the photosensitive layer comprising a specific hole transferring material and/or electron transferring material and a binding resin of a polyester resin which is a substantially linear polymer obtained by using a specific dihydroxy compound represented by the general formula (1): ##STR1## wherein R.sup.1 is an alkylene group having 2 to 4 carbon atoms; and R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are the same or different and indicate a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aryl group or an aralkyl group or the like. This photosensitive material is improved in sensitivity, and is also superior in adhesion to conductive substrate as well as mechanical strength such as wear resistance, etc.

There is disclosed an electrophotosensitive material using a binding resin of a bisphenol C type, bisphenol Z type, bisphenol Z type containing a substituent or bisphenol C-copolymer type polycarbonate in combination with a hole transferring material of a specific benzidine or phenylenediamine derivative. This photosensitive material is superior in mechanical strength and repeat characteristics and has a high glass transition temperature and a high sensitivity.

An image-forming apparatus employing a reversal developing system and using a photosensitive material capable of being charged into both positive and negative polarities and further using a transfer roller made of an electrically conducting sponge rubber. The photosensitive material and the transfer roller are press-contacted to each other with a suitable force, and a DC voltage is applied to the transfer roller, the DC voltage having a polarity opposite to the polarity of the potential created by the main charger and having a value larger than a charge start voltage of the photosensitive material but being so set that the potential on the surface of the photosensitive material after discharged is not larger than 50 V in an absolute value. This apparatus permits a toner image formed on the surface of the photosensitive material to be transferred at a high efficiency and enables the photosensitive material to be uniformly charged in a next cycle of forming image.

Image-forming apparatus employing a reversal developing system

An electrophotographic photoconductor includes: a conductive substrate and a photosensitive layer formed on the conductive substrate, wherein the photosensitive layer includes charge generating particles, a charge transporting material, and a binder resin, and the charge generating particles are made of a composition including a charge generating material dispersed in a binding medium.

Electrophotographic photoconductor having a photosensitive layer with

Disclosed is an organic photosensitive material for electrophotography which is characterized by containing a specific diphenoquinone derivative in an organic photosensitive layer of the material. The diphenoquinone derivative is a compound represented by the following general formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are alkyl groups, alkoxy groups, aryl groups or aralkyl groups, and at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is an aryl group or an aralkyl group, and at least 2 of the remaining R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are alkyl groups or alkoxy groups, the organic photosensitive material mentioned above has excellent sensitivity and residual potential.

Organic photosensitive material for electrophotography

A process for producing an organic photosensitive material preventing brushing by applying an organic solvent solution or a dispersion of an organic photosensitive material onto the surface of a blank tube consisting of an electrically conducting substrate such as of aluminum, wherein when the thickness of the blank tube is denoted as t (cm) and the thickness of the photosensitive material layer as d (cm), the thickness of said photosensitive material layer is so set as to satisfy the following equation, d=kt, wherein k is a number which is 0.13 or smaller. The brushing can be effectively prevented by controlling only the thickness of the blank tube which is forming the photosensitive layer and the thickness of said photosensitive layer.

Process for producing an organic photosensitive material preventing

The present invention provides an electrophotosensitive material having a layer containing a binding resin, a charge transferring material and a biphenyl derivative of the following formula [I], or a compound of which energy level in a triplet state is not more than the energy level in an excited state of the charge transferring material. The present invention prevents the charge transferring material from being decreased in charge amount and sensitivity due to light irradiation: ##STR1## wherein R.sup.1 is an aryl or aralkyl group.

Electrophotosensitive material containing p-benzylbiphenyl

The electrophotosensitive material in accordance with the present invention containing a layer which contains polycarbonate as a binding resin and of which glass transition temperature is not lower than 62.degree. C. This layer is excellent in adhesion to the foundation. This layer may be a photosensitive layer containing a m-phenylenediamine compound as a charge transferring material, or a photosensitive layer containing a m-phenylenediamine compound and a perylene compound as a charge generating material. The present invention also provides a photosensitive layer of which the amount of residual tetrahydrofuran is adjusted to a predetermined value or less, thereby to prevent the photosensitive layer from being decreased in sensitivity due to ultraviolet rays or visible ray.

Growing community of inventors

Osaka, Japan

Masato Katsukawa