Abstract: 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.

Abstract: An electrophotographic element utilizing as a charge generation material a disazo pigment having the following general formula: ##STR1## where R.sup.1 is hydrogen, chlorine, bromine, methyl, ethyl, methoxy, ethoxy, nitro, dimethylamino, diethylamino or phenyl; m and n are each an integer such as 1 or 2; and R.sup.2 is hydrogen or chlorine.

Abstract: A method of rendering a surface of substrate photoconduction comprising applying to the substrate a layer of N-vinyl carbazole and a prepolymer formed thereupon and completely polymerizing the monomer or prepolymer in situ on the substrate.

Abstract: This invention relates to an electrophotographic material comprising an electrically conductive support, a photoconductive layer based on at least one organic photoconductive substance on the support, and a protective layer composed of at least one polymeric substance covering the photoconductive layer, said protective layer containing at least one photoconductive organic compound in a quantity of about 0.1 to 30 percent by weight, based on the weight of polymeric substance.

Abstract: An electrophotographic element comprising a conductive substrate and a mono-layer type or multi-layer type photosensitive layer, superposed thereon, containing a photoconductive material in which said photoconductive material is a hydrazone compound having the following general formula (I) or an anile compound having the following general formula (II): ##STR1## [where R.sub.1 is a methyl, ethyl 2-hydroxyethyl or 2-chloroethyl group; R.sub.2 is a methyl, ethyl, benzyl or phenyl group; and R.sub.3 is chlorine, bromine, a C.sub.1 -C.sub.4 alkyl group, a C.sub.1 -C.sub.4 alkoxy group, a dialkylamino group with C.sub.1 -C.sub.4 alkyl or a nitro group.] ##STR2## [where R.sub.1 is the same as the said general formula (I); and R.sub.4 is a substituted or non-substituted phenyl, naphthyl, heterocyclic or C.sub.1 -C.sub.10 alkyl group.

Abstract: 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.

Abstract: For reversal development of an electrical potential pattern formed by imagewise exposure of a uniformly charged photoconductive layer, the charging of the layer is restricted to such a level below its breakdown voltage that the contact between the photoconductive layer and the toner powder used in the development step is insulating, and a magnetisable and inductively attractable toner powder is applied for the development. The toner powder is applied by means of a magnetic brush device comprising a conductive development roller which is provided with an electrical potential suited for reversal development. Preferably the photoconductive layer is charged to a level of at most 35-75% of its breakdown voltage, and a scorotron preferably is used for the charging. The photoconductive layer may comprise a photoconductive polymer and/or a bisazo pigment as photosensitive compound, or may be a layer of "pink" zinc oxide dispersed in a binder.

Abstract: An electrophotographic plate comprising a conductive substrate and a photosensitive layer containing an organic photoconductor layer composed of a hydrazone compound represented by the general formula (I): ##STR1## (wherein R.sup.1 and R.sup.2 are an alkyl, aralkyl or aryl group which may or may not have a substituent, n is a number of 1 or 2, and A is an aromatic hydrocarbyl group or aromatic heterocyclic group which may or may not have a substituent) and a binder.

Abstract: Electrophotosensitive materials having the structure ##STR1## wherein: Z.sup.1 and Z.sup.2 represent a basic type heterocyclic nucleus;Y represents N or a methine carbon C--G.sup.1 ;G.sup.1 and G.sup.2 may be the same or different and each is H, alkyl, or aryl or taken together complete a mononuclear or fused polynuclear carbocyclic ring;A.sup.1 and A.sup.2 represent alkyl, aryl, carboxy, alkoxycarbonyl, cyano, nitro or together form a heterocyclic nucleus;R.sup.1 and R.sup.2 may be the same or different and each may represent H, alkyl, aralkyl or aryl;R.sup.3 and R.sup.4 represent hydrogen, alkyl, aryl, cyano, or taken together with the atoms to which they are attached represent a 5 to 6 member carbocyclic ring;m and n may be the same or different and may be 0 or 1;p, q and r, which may be the same or different, represent 0, 1 or 2.

Abstract: 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.

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 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: Electrophotosensitive materials having the structure ##STR1## wherein: r and s may be zero, one two or three;R.sup.1 and R.sup.2 may be the same or different and each may represent hydrogen, alkyl, aryl, alkoxyalkyl or alkoxyaryl;Y represents O or S;L.sup.1, L.sup.2, L.sup.3, L.sup.4 and L.sup.5 may be the same or different, represent hydrogen, alkyl, aryl or aralkyl and in addition either L.sup.1 and L.sup.2 or any two of L.sup.3, L.sup.4 and L.sup.5, together with the atoms to which they are attached, may represent the elements needed to complete a carbocyclic ring;A.sup.1 and A.sup.2 represent a substituted or unsubstituted heterocyclic nucleus.