Patent ID: 8076046

Claim:
An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer obtained by laminating at least a charge generation layer and a charge transport layer containing a charge transport material in this order on the conductive support, the photosensitive layer being provided with a surface protective layer on the surface thereof, wherein the protective layer contains at least filler particles which exhibit a dispersed state defined by Rf given by the following equations (1) and (2): Rf =( df×b 3 )/( dm×a 3 ) (1) 1.0×10 −3 ≦Rf≦ 2.5×10 −2 (2) wherein a is an average distance (nm) between fillers, b is an average particle diameter (nm) of fillers, df is a density (g/cm 3 ) of filler particles and dm is an average density (g/cm 3 ) of a solid in the surface protective layer, and a diamine compound represented by the following formula (I): wherein Ar 1 , Ar 2 , Ar 3 and Ar 4 , which may be the same or different, each represent an aryl group, cycloalkyl group or monovalent heterocyclic residue which may have a substituent; Ar 5 represents an arylene group or a divalent heterocyclic residue; and Y 1 , Y 2 , Y 3 , Y 4 , Y 5 and Y 6 , which may be the same or different, each represent a chain alkylene group which may have a substituent.