Ricoh Company, Ltd.

Akio Kozima

Mitsuru Hashimoto

Masafumi Ohta

Masaomi Sasaki

Kiyoshi Sakai

Kyoji Tsutsui

Eiichi Akutsu

Akihiro Yamaguchi

Takamichi Enomoto

Mitsuo Okazaki

Zenjiro Okuno

Tatuya Katoh

Kiyomi Ichizuka

Tatsumi Satoh

The present invention provides disazo compounds expressed by the general formula ##STR1## [wherein A represents ##STR2## (wherein R represents alkyl radical, alkoxy radical, nitro radical, dialkylamino radical or halogen, n is 0 or an integer ranging from 1 to 3, and R may be identical or different when n is an integer of 2 or 3)]; a process for the preparation of said compounds; and photosensitive materials having a high sensitivity as well as a high flexibility which comprises a conductive support and a photosensitive layer formed thereon, said photosensitive layer containing a disazo pigment, as an effective ingredient, which is expressed by the general formula ##STR3## [wherein R' represents a member selected from the group consisting of hydrogen, ethyl radical, chloroethyl radical and hydroxyethyl radical, A' represents a member selected from the group consisting of ##STR4## (wherein X represents a member selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc., heterocyclic rings such as indole ring, carbazole ring, benzofuran ring, etc. and their substituents, Ar.sub.1 represents a member selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc., heterocyclic rings such as dibenzofuran ring, etc. and their substituents, Ar.sub.2 and Ar.sub.3 represent respectively a member selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc. and their substituents, R.sub.1 and R.sub.3 represent respectively a member selected from the group consisting of hydrogen, lower alkyl radical or phenyl radical and their substituents, and R.sub.2 represents a member selected from the group consisting of lower alkyl radical, carboxyl radical and their esters)].

3,6-Disazo-9-ethyl carbazole compounds

The present invention provides an electrophotographic element which comprises a charge generating layer and a charge transport layer formed, in order, on an electroconductive substrate, said charge generating layer comprising a disazo pigment expressed by the general formula: ##STR1## [wherein A represents ##STR2## represents a member selected from the group consisting of benzene ring, naphthalene ring, indole ring, carbazole ring, benzofuran ring and their substitutes; Ar.sub.1 represents a member selected from the group consisting of benzene ring, naphthalene ring, dibenzofuran ring, carbazole ring and their substitutes; each of Ar.sub.2 and Ar.sub.3 represents a member selected from the group consisting of benzene ring, naphthalene ring and their substitutes; each of R.sub.1 and R.sub.3 represents a member selected from the group consisting of hydrogen, lower alkyl radical, phenyl radical and their substitutes; and R.sub.2 represents a member selected from the group consisting of lower alkyl radical, carboxyl radical and alkyl ester thereof)] and a mixture of binder materials comprising polyvinyl butyral and acrylic resin.

Electrophotographic element containing disazo compounds

The present invention provides electrophotographic sensitive materials having a high sensitivity as well as a high flexibility which comprise a conductive support and a photosensitive layer formed thereon, said photosensitive layer containing one disazo pigment, as an effective ingredient, which is selected from the group consisting of disazo pigments expressed by the following general formulas I, II, III, and IV, ##STR1## [(wherein A is selected from the group consisting of ##STR2## is selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as indole ring, carbazole ring, benzofuran ring, etc. and their substituents, Ar.sub.1 is selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as dibenzofuran, etc. and their substituents, Ar.sub.2 and Ar.sub.3 are selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc. and their substituents, R.sub.1 and R.sub.3 are selected from the group consisting of hydrogen, lower alkyl radical or phenyl radical and their substituents and R.sub.2 is selected from the group consisting of lower alkyl radical, carboxyl radical and their esters)].

Electrophotographic sensitive materials containing disazo compounds

An electrophotographic element comprising, in successive layers; a conductive substrate, a charge generation layer and a charge transport layer, the charge generation layer being formed by the steps of; adding to a dispersion comprising a photoconductive organic pigment, a solvent and a resin being superior in mutual solubility with said solvent a resinous solution comprising said solvent and a resin being relatively inferior in mutual solubility with said solvent to the former resin; dispersing (or stirring) the resulting mixture again, thereby obtaining a photoconductive organic pigment-dispersed resinous solution; and applying said resinous solution onto the conductive substrate and drying.

Electrophotographic element with a combination of binder resins

The present invention provides electrophotographic sensitive materials having a high sensitivity as well as a high flexibility which comprise a conductive support and a photosensitive layer formed thereon, said photosensitive layer containing one disazo pigment, as an effective ingredient, which is selected from the group consisting of disazo pigments expressed by the following general formulas I, II, III, and IV, ##STR1##

Electrophotographic sensitive materials containing a disazo pigment

Electrophotographic elements containing disazo compounds

The present invention provides trisazo compounds expressed by the general formula I ##STR1## [wherein A represents ##STR2## (wherein R represents hydrogen, alkyl radical, alkoxy radical, nitro radical, dialkylamino radical or halogen, and n is an integer of 1, 2 or 3, R may be either identical or different when n is an integer of 2 or 3)]; a process for the preparation of said trisazo compounds; and electrophotographic sensitive materials having a high sensitivity as well as a high flexibility which comprise a conductive support and a photosensitive layer containing a trisazo compound, as an effective ingredient thereof, which is expressed by the general formula II ##STR3## [wherein A' represents ##STR4## (wherein Z represents aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as indole ring, carbazole ring, benzofuran ring, etc. or their substituents, Ar.sub.1 represents aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as dibenzofuran ring, etc. or their substituents, Ar.sub.2 and Ar.sub.3 represent aromatic rings such as benzene ring, naphthalene ring, etc. or their substituents, R.sub.1 and R.sub.3 represent hydrogen, lower alkyl radical, phenyl radical or their substituents, and R.sub.2 represents lower alkyl radical, carboxyl radical or their esters)].

Electrophotographic elements containing trisazo compounds

The present invention provides disazo compounds expressed by the general formula I ##STR1## [wherein A represents ##STR2## (wherein R represents alkyl radical, alkoxy radical, nitro radical, dialkylamino radical or halogen, n is 0 or an integer of 1, 2 or 3, and R may be either identical or different when n is an integer of 2 or 3)]; a process for the preparation of said compounds; and electrophotographic sensitive materials having a high sensitivity as well as a high flexibility which comprise a conductive support and a photosensitive layer formed thereon, said photosensitive layer containing a disazo compound, as an effective ingredient, which is expressed by the general formula II ##STR3## [wherein A' represents ##STR4## (wherein X represents aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as indole ring, carbazole ring, benzofuran ring, etc. or their substituents, Ar.sub.1 represents aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as dibenzofuran, etc. or their substituents, Ar.sub.2 and Ar.sub.3 represent aromatic rings such as benzene ring, naphthalene ring, etc. or their substituents, R.sub.1 and R.sub.3 represent respectively hydrogen, lower alkyl radical, phenyl radical or their substituents, and R.sub.2 represents lower alkyl radical, carboxyl radical or their esters)].

Electrophotographic material containing disazo compounds

A photosensitive material for use in electrophotography which comprises a conductive support, a first layer consisting essentially of a substance capable of generating a conductive carrier through light absorption and an electron donor or an electron acceptor, and a second layer consisting essentially of an electron acceptor or an electron donor, to wit, a substance constituting the opposite party of the electron donor or the electron acceptor contained in the first layer, said first and second layers being formed in that order on said conductive support.

Electrophotographic photosensitive material with electron donors and

The present invention provides a layered electrophotographic element which comprises an electroconductive support on which there is a charge generating layer and a charge transfer layer in order, said charge generating layer being consisted essentially of a charge generating agent expressed by the general formula I ##STR1## [wherein A represents ##STR2## (wherein X is selected from the group consisting of benzene ring, naphthalene ring, indole ring, carbazole ring, benzofuran ring and substitutes thereof, Ar.sub.1 is selected from the group consisting of benzene ring, naphthalene ring, dibenzofuran ring, carbazole ring and substitutes thereof, Ar.sub.2 and Ar.sub.3 are selected from the group consisting of benzene ring, naphthalene ring and substitutes thereof, R.sub.1 and R.sub.3 are selected from the group consisting of hydrogen, lower alkyl group, phenyl group and substitutes thereof and R.sub.2 is selected from the group consisting of lower alkyl group, carboxyl group and alkyl esters thereof)], said charge transfer layer being consisted essentially of a charge transfer agent expressed by the general formula II ##STR3## (wherein R.sub.1 represents methyl, ethyl, 2-hydroxyethyl or 2-chloroethyl group and R.sub.2 represents methyl, ethyl, benzyl or phenyl group) and polycarbonate.

Electrophotographic element with carbazole-phenyhydrazone charge

The present invention provides disazo compounds expressed by the general formula I ##STR1## wherein A represents ##STR2## in which R represents alkyl radical, alkoxy radical, nitro radical, dialkylamino radical or halogen, n is 0 or an integer of 1, 2 or 3, and R may be either identical or different when n is an integer of 2 or 3. The disazo compounds are useful as photoconductive substances or charge-carrier generating substances in various kinds of electrophotographic elements.

2-Hydroxy-3-carbonylanilinonaphth-1-yl disazo derivatives and

A photoconductive sensitive material composed of a conductive support and a layer consisting essentially of charge-generating pigment, trinitro-11H-indeno[1,2-b]quinoxaline-11-one and binder resin formed on said support, and a photoconductive sensitive material composed of a conductive support, a thin layer consisting of charge-generating pigment alone or mixed with binder resin and a layer consisting essentially of trinitro-11H-indeno[1,2-b]quinoxaline-11-one and binder resin, said two layers being formed in that order on said support, possess high sensitivity and always give a clear-cut image even when used repeatedly.

Photoconductive sensitive material with a

Electrophotographic light-sensitive member carrying a layer on an electroconductive support, said layer comprising a charge generating substance, a binder and 7-nitro-2-aza-9-fluorenylidene-malonitrile.

Electrophotographic light-sensitive member

3-(-FLUORENYLIDENE)CARBAZOLE DERIVATIVES, PROCESS FOR PREPARING SAME AND ELECTROPHOTOGRAPHIC LIGHT-SENSITIVE MATERIAL CONTAINING 3-(9-FLUORENYLIDENE)CARBAZOLE DERIVATIVES.

3-(9-Fluorenylidene)carbazole derivatives and electrophotographic

A photoconductive sensitive material composed of a conductive support and a photoconductive layer formed thereon, said photoconductive layer consisting essentially of charge generating pigment(s), 2,4,7-trinitrothioxanthone and resinous binder.

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Yokohama, Japan

Akio Kozima