DISPERSION, ELECTROPHOTOGRAPHIC PHOTORECEPTOR, ELECTROPHOTOGRAPHIC PROCESS, ELECTROPHOTOGRAPHIC APPARATUS, AND PROCESS CARTRIDGE FOR ELECTROPHOTOGRAPHIC APPARATUS

摘要

PROBLEM TO BE SOLVED: To obtain a dispersion desirable for making stable electrophotographic photoreceptors by adding a polyvinyl acetal to a dispersion containing titanyl phthalocyanine which has a specified maximum diffraction peak to the characteristic X rays of CuKα. SOLUTION: A polyvinyl acetal having a degree of acetylation of 4 mol.% or above is added to a dispersion containing titanyl phthalocyanine which has a maximum diffraction peak at a Brag angle 2θof 27.2±0.2 deg. to the characteristic X-rays (at a wavelength of 1.541Å) of CuKαto make a dispersion for making a photographic photoreceptor. The polyvinyl acetal used is represented by formula I (wherein R is a 1-5C alkyl; and l, m and n are each the number of the units in the parentheses). The titanyl phthalocyanine has a basic structure represented by formula II (wherein X1 to X4 are various halogens; and p, q, r and k are each a number of 0-4). The combination of this titanyl phthalocyanine with the dispersion containing the polyvinyl acetal as a specified binder gives a photoreceptor which exhibits excellent electrostatic characteristics in repeated use.