Electrophotographic photosensitive member containing disazo compound

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.sub.1, R.sub.1 ', R.sub.2 and R.sub.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.sub.3 and R.sub.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.sub.5 and R.sub.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.sub.7 and R.sub.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.sub.9 and R.sub.10 represent hydrogen, alkyl, aralkyl, aryl or heterocyclic group which may have a substituent.