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AssigneeRicoh Company, Ltd.
InventorsMasaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Kyoji Tsutsui
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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.2 represents a member selected from the group consisting of lower alkyl radical, carboxyl radical and their esters)]; 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 said disazo compound as an effective ingredient.
An electrophotographic material which comprises an electrically conductive support and a photosensitive layer formed thereon, said photosensitive layer consisting essentially of a disazo pigment having a particle size of 5 microns or less, said disazo pigment having the formula ##STR43## wherein A is a member selected from the group consisting of ##STR44## wherein the molecular fragment ##STR45## is a fused polycyclic ring system in which the segment ##STR46## is selected from the group consisting of benzene ring, halobenzene ring, naphthalene ring, indole ring, carbazole ring and benzofuran ring;
An electrophotographic material which comprises an electrically conductive support and a photosensitive layer formed thereon, said photosensitive layer consisting essentially of a disazo pigment having a particle size of 5 microns or less, said disazo pigment having the formula ##STR62## wherein A is a member selected from the group consisting of ##STR63## wherein the molecular fragment ##STR64## is a fused polycyclic ring system in which the segment ##STR65## is selected from the group consisting of benzene ring, halobenzene ring, naphthalene ring, indole ring, carbazole ring and benzofuran ring;
An electrophotographic material which comprises an electrically conductive support and a charge-carrier generating layer formed thereon, said charge-carrier generating layer consisting essentially of a disazo compound having a particle size of 5 microns or less, said disazo pigment having the formula ##STR81## wherein A is a member selected from the group consisting of ##STR82## wherein the molecular fragment ##STR83## is a fused polycyclic ring system in which the segment ##STR84## is selected from the group consisting of benzene ring, halobenzene ring, naphthalene ring, indole ring, carbazole ring and benzofuran ring;
An electrophotographic material which comprises an electrically conductive support, a charge-transfer layer on said support, said charge-transfer layer consisting essentially of a charge-transfer substance and a resinous binder, and a charge-carrier generating layer on said charge-transfer layer, said charge-carrier generating layer consisting essentially of a disazo compound having a particle size of 5 microns or less, said disazo pigment having the formula ##STR100## wherein A is a member selected from the group consisting of ##STR101## wherein the molecular fragment ##STR102## is a fused polycyclic ring system in which the segment ##STR103## is selected from the group consisting of benzene ring, halobenzene ring, naphthalene ring, indole ring, carbazole ring and benzofuran ring;
Dependencies are inferred from the claim text.