| abstract |
A polyester polymer comprising repeating units (I), or repeating units (I) and (II), and having a reduced viscosity ( eta sp/c) of 0.2 to 10.0 dl/g, measured at 20 DEG C. as a 0.5 g/dl solution dissolved in methylene chloride is prepared by allowing a dihydric phenol (III), or dihydric phenols (III) and (IV), to react with a carbonate precursor or a dibasic acid. An electrophotographic photoreceptor which comprises an electroconductive substrate and a photosensitive layer disposed on the electroconductive substrate and containing the polyester polymer as a charge transporting material or a binder resin. (WXOCO) (I) <IMAGE> (II) HOXOH (III) <IMAGE> (IV) wherein, W is -O- or single bond, X is a divalent group which is derived from a dihydric phenol containing a hydrazine structure, each of R25 and R26 is a halogen atom, an alkyl group, a cycloalkyl group or an aryl group, each of m and n is an integer of 0 to 4, Y is single bond, -O-, -S-, -SO-, -SO2-, -CR27R28-, a 1,1-cycloalkylene group or an alpha , omega -alkylene group. |