Abstract: A novel disazo compound is provided which is represented by the general formula (I): ##STR1## (wherein, R.sub.1 and R.sub.2 each stands for hydrogen, a lower alkyl group with 1-4 carbon atoms, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted hetero ring group. R.sub.1 and R.sub.2 may be the same or different. And, R.sub.1 and R.sub.2 may mutually bond to form a ring).This disazo compound may be obtained by diazotating 2,6-diaminoanthraquinone and reacting the same with a coupler represented by the general formula (IV): ##STR2## (wherein, R.sub.1 and R.sub.2 are the same as defined above). Further, a multilayer type electrophotographic element is provided which comprises a charge carrier generating layer and a charge transfer layer and uses, as a charge carrier generating substance, a disazo compound represented by the general formula (I).

Abstract: A novel tetrazonium salt compound having the general formula (II), namely an intermediate useful for synthesis of a wide scope of disazo compounds, was obtained: ##STR1## wherein Y is an anion functional group. A novel disazo compound is further disclosed having the general formula (I): ##STR2## wherein X is a substituted or unsubstituted aromatic ring or hetero ring, and Ar is a substituted or unsubstituted aromatic ring or hetero ring, together with a method for making said disazo compound which comprises using, as a starting material, 2,7-diaminoanthraquinone having the formula (III): ##STR3## and a coupler having the general formula (IV): ##STR4## wherein X and Ar are the same as defined above. Further, a multilayer type electrophotographic element comprising a charge carrier generating layer and a charge transfer layer and using, as a charge carrier generating substance, said disazo compound having the general formula (I), was provided.

Abstract: A layered electrophotographic photoconductor whose charge generation layer comprises a bisazo pigment selected from the group consisting of the bisazo pigments represented by the following general formula (I) and whose charge transport layer contains a charge transport material selected from the group consisting of the hydrazone compounds represented by the following general formula (2): ##STR1## wherein A represents --C.sub.6 H.sub.4 --Cl(o), --C.sub.6 H.sub.4 --Cl(m), --C.sub.6 H.sub.4 --Br(o), --C.sub.6 H.sub.4 --Br(m), --C.sub.6 H.sub.4 --F(o), --C.sub.6 H.sub.4 --F(m), --C.sub.6 H.sub.4 --F(p), or --C.sub.6 H.sub.4 --I(m), ##STR2## wherein R.sup.

Abstract: An electrophotographic photoconductor is prepared by forming a photoconductive layer containing a hydrazone compound therein on an electroconductive support member. The hydrazone compounds represented by the following general formula, are useful as photoconductive materials and as charge transport materials for use in electrophotography: ##STR1## wherein R.sub.1 represents a methyl group, an ethyl group, a 2-hydroxyethyl group, or a 2-chloroethyl group, and R.sub.2 represents a methyl group, an ethyl group, a benzyl group or a phenyl group.

Abstract: An electrophotographic element comprising an electrically conductive substrate and a photosensitive layer, superposed thereon, containing a carbazole derivative compound having the following general formula (I): ##STR1## (wherein R is a lower alkyl group or a benzyl group; X is a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, an amino group or a lower alkyl group- or benzyl group-substituted amino group; and n is an integer such as 1 or 2).

Abstract: A disazo compound having the general formula (1) ##STR1## (wherein X represents a substituted or unsubstituted aromatic ring or hetero ring, and Ar represents a substituted or unsubstituted aromatic ring or hetero ring);a method of making said disazo compound which comprises using, as a starting material, couplers having the general formula (2) ##STR2## and the general formula (4) ##STR3## (wherein X and Ar are the same as defined above); and a multilayer type electrophotographic element using said disazo compound as a charge transfer substance.

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: A layered electrophotographic photoconductor whose charge generation layer comprises a bisazo pigment selected from the group consisting of the bisazo pigments represented by the following general formula (1) and whose charge transport layer contains a charge transport material selected from the group consisting of the hydrazone compounds represented by the following general formula (2): ##STR1## wherein A represents --C.sub.6 H.sub.4 --Cl(o), --C.sub.6 H.sub.4 --Cl(m), --C.sub.6 H.sub.4 --Br(o), --C.sub.6 H.sub.4 --Br(m), --C.sub.6 H.sub.4 --F(o), --C.sub.6 H.sub.4 --F(m), --C.sub.6 H.sub.4 --F(p), or --C.sub.6 H.sub.4 --I(m); ##STR2## wherein R.sup.1 represents a methyl group, an ethyl group, a 2-hydroxyethyl group or a 2-chloroethyl group; R.sup.2 represents a methyl group, an ethyl group, a benzyl group or a phenyl group; and R.sup.3 represents hydrogen, chloride, bromide, an alkyl group with one to four carbon atoms, an alkoxy group with one to four carbon atoms, a dialkylamino group, or a nitro group.

Abstract: A layered electrophotographic photoconductor whose charge generation layer comprises a bisazo pigment selected from the group consisting of the bisazo pigments represented by formula (1) and whose charge transport layer contains a charge transport material selected from the group consisting of anthrancene compounds represented by formula (2) or from the group consisting of distyrylbenzene compounds represented by formula (3) ##STR1##

Abstract: An electrophotographic photoconductor is prepared by forming a photoconductive layer containing a hydrazone compound therein on an electroconductive support member. The hydrazone compounds represented by the following general formula, are useful as photoconductive materials and as charge transport materials for use in electrophotography: ##STR1## wherein R.sub.1 represents a methyl group, an ethyl group, a 2-hydroxyethyl group, or a 2-chloroethyl group, and R.sub.2 represents a methyl group, an ethyl group, a benzyl group or a phenyl group.

Abstract: An electrophotographic photoconductor comprising, on an electroconductive support material, a photoconductive layer containing a bisazo pigment having a phenanthrenequinone substituent, which electrophotographic photoconductor exhibits relatively high photosensitivity and usefullness for electrophotographic copying.

Abstract: An electrophotographic element is prepared by forming a photoconductive layer containing a hydrazone compound therein on an electroconductive support member. The hydrazone compounds represented by the following general formula, are useful as photoconductive materials and as charge transport materials for use in electrophotography: ##STR1## wherein Ar represents a substituted or unsubstituted condensed polycyclic group or heterocyclic group, and R represents a methyl group, an ethyl group, a benzyl group or a phenyl group. The condensed polycyclic group includes a naphthalene ring, and an anthracene ring. The heterocyclic ring includes nitrogen, oxygen and sulfur.

Abstract: Hydrazone compounds having the general formula ##STR1## wherein Ar is selected from the group consisting of a naphthalene ring radical, substituted naphthalene ring radicals, an anthracene ring radical, substituted anthracene ring radicals, styryl, substituted styryls, a pyridine radical, a furan ring radical and a thiophene ring radical.The hydrazone compounds can be prepared by allowing 1-methyl-1-phenylhydrazine having the formula ##STR2## to react with an aldehyde represented by the general formula Ar-CHO, wherein Ar is the same as mentioned above at a substantially equal molar ratio in an organic solvent selected from the group consisting of lower alcohols, cyclic ethers, cellosolves, N,N-dimethylforamide and acetic acid, in the presence of an acid catalyst, by heating and refluxing the reaction mixture.

Abstract: An electrophotographic element comprising an electrically conductive support and a mono-layer or multi-layer type photosensitive layer, superposed thereon, containing as an active ingredient a disazo pigment having the following general formula: ##STR1## where Ar is a substituted or non-substituted phenyl, substituted or non-substituted naphthyl, anthryl, pyrenyl, pyridyl, thienyl, furyl or carbazolyl group.

Abstract: A bis-azo compound of the formula ##STR1## wherein A represents ##STR2## wherein R represents alkyl, alkoxy, nitro, dialkylamino or halogen, and n represents an integer 0, 1, 2 or 3 and when n is 2 or 3, R represents identical or different substituents selected from the group of alkyl, alkoxy, nitro, dialkylamino and halogen. The bis-azo compound is useful as a photoconductive material for the preparation of electrophotographic photoconductors.

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: 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##

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 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.