Electrophotographic photosensitive member, manufacturing method of electrophotographic photosensitive member, process cartridge and electrophotographic apparatus, and phthalocyanine crystal and manufacturing method of phthalocyanine crystal

Abstract

The present invention provides: an electrophotographic photosensitive member which reduces image defects due to ghosting not only under a normal temperature and normal humidity environment but also even under a low temperature and low humidity environment; and a novel phthalocyanine crystal. The electrophotographic photosensitive member of the present invention comprises a photosensitive layer which comprises a phthalocyanine crystal in which a N,N-dimethylformamide is contained. The content of the N,N-dimethylformamide is 0.1% by mass or more and 1.5% by mass or less based on the phthalocyanine crystal.

What is claimed is: 
     
         1 . An electrophotographic photosensitive member comprising:
 a support; and   a photosensitive layer on the support,   wherein the photosensitive layer comprises:   a phthalocyanine crystal in which a N,N-dimethylformamide is contained, and   wherein the content of the N,N-dimethylformamide is 0.1% by mass or more and 1.5% by mass or less based on a phthalocyanine in the phthalocyanine crystal.   
     
     
         2 . The electrophotographic photosensitive member according to  claim 1 , wherein
 the phthalocyanine crystal is a hydroxygallium phthalocyanine crystal having peaks at Bragg angles 2θ of 7.5°±0.2°, 9.9°±0.2°, 25.2°±0.2° and 28.3°±0.2° in CuKα characteristic X-ray diffraction; and   the intensity of a peak emerging at 9.9°±0.2° is 2.0 or more times the intensity on a side 2.8° wider from the angle of the peak emerging at 9.9°±0.2°.   
     
     
         3 . The electrophotographic photosensitive member according to  claim 1 , wherein
 the content of the N,N-dimethylformamide is 0.8% by mass or more and 1.3% by mass or less based on the phthalocyanine in the phthalocyanine crystal.   
     
     
         4 . A process cartridge which integrally supports: an electrophotographic photosensitive member according to  claim 1 ; and at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit, the cartridge being detachably mountable to a main body of an electrophotographic apparatus. 
     
     
         5 . An electrophotographic apparatus comprising:
 an electrophotographic photosensitive member according to  claim 1 ; and   a charging unit, an exposing unit, a developing unit and a transferring unit.   
     
     
         6 . A phthalocyanine crystal in which a N,N-dimethylformamide is contained,
 wherein the content of the N,N-dimethylformamide is 0.1% by mass or more and 1.5% by mass or less based on a phthalocyanine in the phthalocyanine crystal.   
     
     
         7 . The phthalocyanine crystal according to  claim 6 , wherein the phthalocyanine crystal is obtained by performing a crystal transformation by milling a mixture of the phthalocyanine and the N,N-dimethylformamide, wherein a time period for the milling is 250 hours or more. 
     
     
         8 . The phthalocyanine crystal according to  claim 7 , wherein the phthalocyanine is obtained by an acid pasting method prior to the step of performing the crystal transformation.