Mitsubishi Paper Mills Limited

Makoto Okaji

Akira Itoh

Kazuhiro Emoto

Kozo Haino

Tamotsu Horiuchi

Kazuchiyo Takaoka

Hideki Nagamura

Tatsuya Kodera

Kazuyuki Suruga

Hideya Arisue

Michihiko Sato

Phthalocyanine composition, process for production thereof, and electrophotographic photoreceptor

Disclosed are a phthalocyanine composition having main diffraction peaks at 7.0&deg;, 9.0&deg;, 14.1&deg;, 18.0&deg;, 23.7&deg; and 27.3&deg; of Bragg angles (2&thgr;&plusmn;0.2&deg;) in an X-ray diffraction spectrum with Cu K&agr;, a process for producing the same and an electrophotographic photoreceptor using the same.

Phthalocyanine, process for producing the same and electrophotographic photoreceptor using the same

Oxytitanium phthalocyanine having a novel crystal form having excellent electrophotographic properties, such as a high charge potential, a high sensitivity and stable performances free from causing changes in various properties in repeated use, can be produced in the absence of a halogen substance, by carrying out the crystal transformation of amorphous oxytitanium phthalocyanine in a solvent comprising water and naphthalene.

Oxytitanium phthalocyanine process for the production thereof and electrophotographic photoreceptor to which the oxytitanium phthalocyanine is applied

The present invention provides an electrophotographic photoreceptor which comprises an electrically conductive support and a light-sensitive layer which contains an azo pigment represented by the following formula (I): ##STR1## wherein R.sub.1 represents an unsubstituted or substituted alkyl or alkoxy group having 3 to 8 carbon atoms, R.sub.2 represents a hydrogen atom, a halogen atom or an unsubstituted or substituted alkyl or alkoxy group having 1 to 3 carbon atoms and m and n each represent 1 or 2.

Electrophotographic photoreceptor containing an azo pigment

Disclosed is a double-layered type electrophotographic photoreceptor which comprises an electroconductive support and a carrier generation layer containing a pigment or a dye as a carrier generation material and a carrier transport layer which are provided on said support, wherein the carrier transport layer contains an organic low molecular weight carrier transport material, a binder resin, a hydroquinone compound represented by the following formula (II): ##STR1## wherein R.sup.7, R.sup.8, R.sup.9 and R.sup.10 each represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, a carbamoyl group or an alkylthio group, and a compound represented by the following formula (III): ##STR2## wherein R.sup.11, R.sup.12, R.sup.13 and R.sup.14 each represents a hydrogen atom, a hydroxyl group, an alkyl group or an alkoxy group with a proviso that at least one of R.sup.11 -R.sup.14 is hydroxyl group, R.sup.15 and R.sup.16 each represents a hydrogen atom, an alkyl group or an alkenyl group and Z represents a group of atoms necessary to form a 2H-chromene skeleton, chroman skeleton or dihydrobenzofuran skeleton together with the benzene ring in the formula and the group of atoms may be further substituted.

Electrophotographic photoreceptor with a carrier transport layer

Disclosed is an electrophotographic photoreceptor which is high in sensitivity and endurance and which comprises an electroconductive support and, provided thereon, a photosensitive layer which contains a hydrozone compound represented by the following formula [I], [II], or [III]: ##STR1## wherein the various subgroups designated by R or A are as described in the specification.

Novel hydrazone compound in an electrophotographic receptor

This invention provides an electrophotographic photoreceptor which is high in durability and high in sensitivity. This photoreceptor comprises an electroconductive support and, provided thereon, a photosensitive layer containing an azo pigment represented by the following formula [I] or [II]: ##STR1## wherein A represents a hydrogen atom, an alkyl group, a phenyl group or a heterocyclic ring group, m and n each represents 0 or 1, X represents a hydrogen atom, a lower alkyl group, a cyano group or a halogen atom and Cp represents a coupler residue, or ##STR2## wherein Z represents an alkyl group, a phenyl group or a heterocyclic ring group, X represents a hydrogen atom, a lower alkyl group, a cyano group or a halogen atom and Cp represents a coupler residue.

Electrophotographic disazo photoreceptor

Disclosed is an electrophotographic photoreceptor which is high is sensitivity and high in endurance and which contains in photosensitive layer a novel stilbene compound represented by the following formulas [I], [II], or [III]: ##STR1##

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Tokyo, Japan

Makoto Okaji