PURPOSE: To improve the electrostatic chargeability of the electrophotographic sensitive body provided with a photosensitive layer contg. a poly(biphenylyl) amine compd. having a specific structure and to lower the relative humidity at and under a high temp. and high humidity as well as to prevent the dew condensation on the photosensi tive body at the time of a low temp. by subjecting the photosensitive body to a heating treatment in an image forming device or on the outside of the image forming device.
CONSTITUTION: The delay in the rising of the electrostatic charge potential equal to the rise before repetitive use is eliminated and distinct copied images are obtd. in spite of the repetitive use if the poly(biphenylyl) amine compd. expressed by general formula (I) is incorporated into the photosensitive layer of the electrophotographic sensitive body and the photosensitive body is previously heated in the dark place in the image forming device or on the outside of the image forming device. (In the formula, Ar denotes a substd. or unsubstd. monocyclic arom. hydrocarbon group, substd. or unsubstd. non-condensed polycyclic arom. hydrocarbon group or substrate or unsubstd. heterocyclic group.) The stresses on the surface of the photosensitive body increase if the heating treatment temp. is increased too high and, therefore, the lower limit is preferably ≥40°C and the upper limit ≤100°C.
UMEDA MINORU
SASAKI MASAOMI
ARIGA TAMOTSU
SHIMADA TOMOYUKI
