| 摘要 |
PURPOSE:To obtain a good offset master with a raw paper of supporting base which does not expand with water by forming an undercoated layer containing wax in the range of specific quantity on the surface of the raw paper of supporting base, and further providing a water- resistant layer and a photoconductive layer in turn, and providing a layer of conductive treatment on the reverse side of the raw paper. CONSTITUTION:The undercoated layer 2 containing 5-20wt% polyethylene wax and paraffin wax or the like is formed on the surface of the raw paper of supporting base 1. The layer 2 is formed in about 10g/m<2> by being coated with the mixture of the following; for instance, the mixture which wax is mixed with water-soluble resins like polyvinyl alcohol or the like and emulsion resins like polyvinyl chloride or the like, pigments like clay or the like as a binder, high-polymer electrolyte as a conductive agent and melamine resins or the like as a cross-linking agent. The water-resistant layer (isoprene maleic anhydride copolymer resins or the like) 3 is provided on the layer 2, and then the photoconductive layer 4 with sensitizing dye and photoconductive ZnO or the like dispersed in the resins is provided on the layer 3. The conductive layer 5 is formed with resins containing conductive material (quaternary ammonium high polymer or the like) on the reverse side of the raw paper and the original plate for lithophotography of dry electrophotography with superior resistance to printing is obtained. |
