Mita Industrial Co., Ltd.

Tatsuo Maeda

Eiichi Miyamoto

Nariaki Muto

Keisuke Sumida

Mikio Kakui

Toru Nakazawa

Nariaki Mutou

Tooru Nakazawa

Eiji Nimura

Yasufumi Mizuta

Hiroaki Iwasaki

Yumiko Sano

Masato Katsukawa

Toshihiko Nishiguchi

Hirotsugu Nishikawa

Teruyo Morimoto

Yuji Tomii

The electrophotographic photoconductor of the present invention includes a conductive substrate and a photosensitive layer containing perylene pigment as a charge generating material formed on the conductive substrate. The X-ray diffraction peak of the perylene pigment exhibits its peak when the value of 2.theta. is 14.degree.(.+-.0.3.degree.), and the half-width of the peak when the value of 2.theta. is 14.degree. (.+-.0.3.degree.) is 0.5 or more. This electrophotographic photoconductor has excellent qualities of low residual potential and stabilized quality.

Electrophotographic photoconductor and a method for preparing the same

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

This invention provides an electrophotosensitive material comprising a conductive substrate and a photosensitive layer formed thereon, the photosensitive layer includes a perylene compound (I) and an X-type metal-free phtalocyanine as a charge-generating ingredient and a diamine derivative (II) as a charge-transferring ingredient in the binding resin. This electrophotosensitive material is especially superior in sensitivity and reproductivity. Formulas (I) and (II) are defined as follows: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.9 l, m, n, o and p have the same meanings as defined in the text of the specification.

Electrophotosensitive material with x-type metal free phthalocyanine and

A stable .alpha.-type titanyl phthalocyanine composition including an .alpha.-type titanyl phthalocyanine and a metal-free phthalocyanine is disclosed having a wide range of absorption wavelengths and high in spectral sensitivity. The method for making the phthalocyanine composition is carried out by pigmenting a concentrated sulfuric acid solution containing at least titanyl phthalocyanine by an acid paste process. The concentrated sulfuric acid solution is poured into water to produce an .alpha.-type titanyl phthalocyanine composition which is stable to withstand the impact of aging. Also disclosed is an electrophotographic sensitive material which includes a sensitive layer having the .alpha.-type titanyl phthalocyanine composition superposed on an electroconductive substrate. This electrophotographic sensitive material excels in its charging property and its dark attenuation property and exhibits high sensitivity and low residual potential. The electrophotographic sensitive material having a sensitive layer comprising the .alpha.-type titanyl phthalocyanine composition and an electric charge transferring material can also be superposed on an electroconductive substrate. This electrophotographic photosensitive material exhibits an oxidation potential in the ranage of 0.45 to 0.65 eV, enjoys high sensitivity, and shows low residual potential.

.alpha.-type titanyl phthalocyanine composition, method for production

The present invention provides an electrophotosensitive material containing the diamine derivative represented by the following general formula (I) and at least one selected from the group consisting of the hydrazone compound, fluorene compound and m-phenylenediamine compound. ##STR1## wherein R.sup.5 to R.sup.9, l, m, n, o and p are as defined.

Electrophotosensitive material with combination of charge transfer

The first aspect of this invention resides in providing an .alpha.-type titanyl phthalocyanine composition comprising an .alpha.-type titanyl phthalocyanine and metal-free phthalocyanine. This .alpha.-type titanyl phthalocyanine composition is stable, wide in range of absorption wavelengths, and high in spectral sensitivity because it contains an .alpha.-type titanyl phthalocyanine in combination with metal-free phthalocyanine. The second aspect of this invention resides in providing a method for the production of an .alpha.-type titanyl phthalocyanine composition comprising an .alpha.-type titanyl phthalocyanine and a metal-free phthalocyanine, which method comprises pigmenting a concentrated sulfuric acid solution containing at least titanyl phthalocyanine by the acid paste process consisting in pouring said concentrated sulfuric acid solution into water. By this method, an .alpha.-type titanyl phthalocyanine composition stable to withstand the impact of aging can be easily produced.

Disclosed is a photoconductive toner comprising as a main component a photoconductive substance dissolved or dispersed in a binder resin medium, wherein when the photoconductive substance is a p-type semiconductor, it is combined with a binder resin having a positive tribochargeability and when the photoconductive substance is an n-type semiconductor, it is combined with a binder resin having a negative tribochargeability.

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Kobe, Japan

Tatsuo Maeda