| 摘要 |
PURPOSE:To improve density of picture image by using a specified copolymer resin layer contg. fine silica particles and polyvinyl alcohol as precoating layer. CONSTITUTION:At least one kind of vinyl chloride/acrylic ester copolymer resin, polyvinyl alcohol, and fine silica particles are incorporated in a precoating layer, and simultaneously, the proportion of the acrylic ester in the copolymer compsn. is regulated to 20-70wt% expressed in terms of monomer unit. If the content of the acrylic ester in the copolymer resin is <20wt%, the density of the picture image is reduced. If the content of the acrylic ester exceeds 70wt%, scumming during dry development becomes remarkably heavier. It is preferred that the amt. of the fine silica particles to be used is regulated to 0.1-5pts.wt. basing on 1pt.wt. resin. The density of picture image is improved by using the precoating resin and fine silica particles. |
