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AssigneeRicoh Company, Ltd.
InventorsMasafumi Ohta, Kiyoshi Sakai, Mitsuru Hashimoto, Akio Kozima, Masaomi Sasaki
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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)].
An electrophotographic material which comprises an electrically conductive support and a photosensitive layer formed thereon, said photosensitive layer consisting essentially of fine particles of a trisazo compound having the formula ##STR52## is a fused ring selected from the group consisting of benzene ring, bromobenzene 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 fine particles of a trisazo compound having the formula ##STR73## is a fused ring selected from the group consisting of benzene ring, bromobenzene ring, naphthalene ring, indole ring, carbazole ring and benzofuran ring;
An electrophotographic material which comprises a charge-carrier generating layer and a charge-transfer layer as formed on an electrically conductive support, said charge-carrier generating layer consisting essentially of fine particles of a trisazo compound having the formula ##STR94## is a fused ring selected from the group consisting of benzene ring, bromobenzene ring, naphthalene ring, indole ring, carbazole ring and benzofuran ring;
Dependencies are inferred from the claim text.