| 摘要 |
PURPOSE: To suppress dispersion and gradient in electrification in the thickness direction of a developer layer on the surface of a developing roll,to suppress the occurrence of a ghost image, and to obtain good picture quality in a excel lent density by using a polyvinylbutyral-phenol resin blend as a film forming resin material to form a semiconducting coating layer. CONSTITUTION: A polyvinyl butyral-phenol resin blend is used as a film forming resin material which constitutes a semiconducting coating layer 22 of a developer roll 2 used for a one-component developing method. This resin blend is a thermosetting resin prepared by blending a phenol resin and polyvinyl butyral which is one kind of adhesive to form a vinyl phenol resin structure. Generally, 1-20 pts.wt. of phenol resin is compounded to 10 pts.wt. of polyvinyl butyral. It is advantageous to incorporate >=2% polyvinyl butyral-phenol resin blend having >=1.64×10mol.wt. measured by gel permeation chromatography. |
