Electrophotographic photosensitive member containing disazo compound

Claim 1

An electrophotographic photosensitive member comprising a photosensitive layer on a substrate, said photosensitive layer comprising a disazo pigment represented by the formula: ##STR17## wherein R 1 , R 1 ', R 2 and R 2 ' represent hydrogen, halogen, nitro, cyano, or alkyl, aralkyl, alkoxy or aryl group which may have a substituent, A represents a coupler residue having a phenolic OH group, and B represents hydrogen or nitroso group, said A being selected from the formulas (2) to (8) shown below: ##STR18## wherein X represents a residue to be fused with a benzene ring to form a polycyclic aromatic ring of anthracene ring, or a heterocyclic ring; R 3 and R 4 represent hydrogen, alkyl, aralkyl, aryl or heterocyclic ring which may have a substituent, or taken together represent a residue to form a cyclic amino group together with nitrogen atom; R 5 and R 6 each represent alkyl, aralkyl, aryl which may have a substituent; Y represents a divalent aromatic hydrocarbon group or forms a divalent heterocyclic group together with nitrogen atom; Z represents a residue to be fused with a benzene ring to form a polycyclic aromatic ring or heterocyclic ring; R 7 and R 8 represent hydrogen, aryl or heterocyclic group which may have substituent or a residue which forms a 5- to 6-membered ring together with the center carbon atom, which 5- to 6-membered ring may have a fused aromatic ring; R 9 and R 10 represent hydrogen, alkyl, aralkyl, aryl or heterocyclic group which may have a substituent.