Abstract: Disclosed are a phthalocyanine composition suitable for use in an electrophotographic photoreceptor that exhibits a high charge potential and a high sensitivity and which exhibits stable performances without causing a change in various properties in repeated use, a process for the production thereof, and an electrophotographic photoreceptor to which the above phthalocyanine composition is applied. The present invention provides a phthalocyanine composition comprising a oxytitanium phthalocyanine and a metal-free phthalocyanine and having a crystal form having peaks at Bragg angles (2&thgr;±0.2°) of 7.0°, 9.0°, 14.1°, 18.0°, 23.7° and 27.3°, and having no peak at a Bragg angle (2&thgr;±0.2°) of 9.5°, in CuK&agr; 1.

Abstract: Disclosed are a phthalocyanine composition having main diffraction peaks at 7.0°, 9.0°, 14.1°, 18.0°, 23.7° and 27.3° of Bragg angles (2&thgr;±0.2°) in an X-ray diffraction spectrum with Cu K&agr;, a process for producing the same and an electrophotographic photoreceptor using the same.

Abstract: Disclosed are a phthalocyanine composition suitable for use in an electrophotographic photoreceptor that exhibits a high charge potential and a high sensitivity and which exhibits stable performances without causing a change in various properties in repeated use, a process for the production thereof, and an electrophotographic photoreceptor to which the above phthalocyanine composition is applied.

Abstract: The present invention provides an electrophotographic photoreceptor high in sensitivity and endurance and highly resistant against oxidizing action with ozone or the like which comprises an electrically conductive support and, provided thereon, a light-sensitive layer which contains at least one azo compound containing a coupler component represented by the following formula [I] or [II]: ##STR1## wherein X represents a heterocyclic or aromatic ring residue which may have a substituent fusing with the benzene ring, Y represents a linkage group, R.sup.1 -R.sup.4 each represents a hydrogen atom or an alkyl group and R.sup.5 represents a hydrogen atom or an alkyl, aralkyl or acyl group which may have a substituent; ##STR2## wherein X and Y are as defined above and R.sup.6 and R.sup.7 each represents a hydrogen atom or an alkyl group which may have a substituent.

Abstract: The invention provides an electrophotographic photoreceptor of high sensitivity and high endurance which comprises a conductive support and a light-sensitive layer which contains at least one bis-azo compound selected from the group consisting of those represented by the following formulas (I)-(II): ##STR1## wherein n represents 0, 1, or 3; R.sup.1 represents a halogen atom, a hydroxyl group, or an alkyl, aralkyl, aryl, hyterocyclic or alkoxy group which may have a substituent and when n is 2 or 3, R.sup.1 may be identical or different; R.sup.2 represents a hydrogen atom, a halogen atom, a cyano group, or an ester, alkyl, aralkyl or aryl group which may have a substituent; R.sup.3 represents an alkyl, aralkyl, aryl or heterocyclic group which may have a substituent; Ar represents an arylene which may have a substituent; and A.sup.1 and A.sup.2 each represents an aryl or heterocyclic group which has a hydroxyl group and may be identical or different.

Abstract: The present invention provides an electro-photographic photoreceptor which is high in sensitivity and endurance which comprises an electroconductive support and, provided thereon, a photosensitive layer which contains a compound represented by the following formula [I]: ##STR1## wherein R.sup.1 and R.sup.2 each represents a hydrogen atom or an alkyl, aralkyl or aryl group which may have substituent: X represents ##STR2## in which R.sup.3 and R.sup.4 each represents an alkyl, aralkyl or aryl group which may have substituent and R.sup.5 and R.sup.6 each represents a hydrogen atom or an alkyl, aralkyl or aryl group which may have substituent and R.sup.5 and R.sup.6 may link to each other to form a ring; and Z represents a group of atoms necessary for forming a saturated 5-8 membered ring together with two carbon atoms of the indoline ring.