Abstract: 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.

Abstract: The present invention provides an electrophotographic element of a high sensitivity and a high flexibility comprising an electroconductive support and a photosensitive layer provided thereon and containing as an effective ingredient therein a disazo compound represented by the following general formula: ##STR1## wherein A is a radical selected from the group consisting of: ##STR2## in which X represents a ring selected from the group consisting of aromatic rings such as benzene ring and naphthalene ring, hetero rings such as indole ring, carbazole ring and benzofuran ring, and substituted derivatives thereof; Ar.sub.1 represents a radical selected from the group consisting of aromatic rings such as benzene ring and naphthalene ring, hetero rings such as dibenzofuran ring and substituted derivatives thereof; Ar.sub.2 and Ar.sub.3 represent radicals respectively selected from the group consisting of aromatic rings such as benzene ring and naphthalene ring, and substituted derivatives thereof; R.sub.1 and R.sub.

Abstract: The present invention provides disazo compounds expressed by the general formula: ##STR1## [wherein A represents a member selected from the group consisting of ##STR2## (wherein X represents a member 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 represents a member selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as dibenzofuran ring, etc. and their substituents, Ar.sub.2 and Ar.sub.3 represent 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 a member selected from the group consisting of hydrogen, lower alkyl radical or phenyl radical and their substituents and R.sub.

Abstract: The present invention provides disazo compounds expressed by the general formula I ##STR1## a process for the preparation of said compounds; and electrophotographic sensitive material 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 A'--N.dbd.N--Z--N.dbd.N--A'.

Abstract: The present invention provides an electrophotographic element which comprises some disazo pigment expressed by the general formula ##STR1## [wherein R.sub.1 represents a member selected from the group consisting of hydrogen atom, methyl radical, ethyl radical, methoxy radical, ethoxy radical, chlorine atom, bromine atom, nitro radical, dimethylamino radical, diethylamino radical and phenyl radical; A represents ##STR2## (wherein R.sub.2 represents hydrogen atom or chlorine atom) or ##STR3## and n is an interger of 1 or 2.] as effective component contained in the photosensitive layer thereof.

Abstract: An electrophotographic element according to the present invention exhibits an exceedingly high sensitivity and it comprises (1) an electroconductive support, a charge producing layer consisting essentially of a charge producing substance and a charge transport layer consisting essentially of a charge transport substance having the following general formula and a binder, the last-mentioned two layers being superposed in that order or vice versa on said support, or (2) an electroconductive support and a photosensitive layer, superposed thereon, and consisting essentially of a charge producing substance, a charge transport substance having said general formula and a binder: ##STR1## (wherein n is an integer of 1 or 2, R.sub.1 stands for hydrogen atom or an alkyl, nitro, dialkylamino, alkoxy, nitrile or carboxylic ester group, and R.sub.2 and R.sub.3 stand for hydrogen or halogen atom or nitro or dialkylamino group respectively).

Abstract: 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.

Abstract: The present invention provides an electrophotographic sensitive element which comprises an electroconductive support and a photosensitive layer formed thereon and containing some charge-carrier generating pigment and a specific charge transfer substance. Said specific charge transfer substance is just a substance selected from well-known photoconductive substances, but when it is applied in combination with a charge-carrier generating pigment, it renders a photosensitive element having a remarkably improved sensitivity.

Abstract: 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.

Abstract: The present invention provides 1,3,7-trinitrophenazine-5-oxide which has an excellent sensitization effect on organic photoconductors, as well as a photoconductive sensitive material comprising said compound and an organic photoconductor.

Abstract: 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.

Abstract: 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.

Abstract: Trinitro-11H-indeno[1,2-b]quinoxaline-11-one obtained by further nitrating 11H-indeno[1,2-b]quinoxaline-11-one, or mononitro- or dinitro-derivatives thereof, demonstrates a conspicuous sensitization effect with respect to organic photoconductors.

Abstract: The present invention provides 1,3,7-trinitrophenazine-5-oxide which has an excellent sensitization effect on organic photoconductors, as well as a photoconductive sensitive material comprising said compound and an organic photoconductor.