| 摘要 |
PURPOSE: To enhance adhesive properties of a supporting body and a hydrophilic layer by incorporating a hydrophilic binder and silica into an undercoating layer. CONSTITUTION: The lithographic base comprises an undercoating layer contiguous to a hydrophilic layer which contains a hydrophilic (co)polymer or (co)polymer mixture and is hardened with a hydrolyzed tetraalkyl orthosilicate crosslinking binder, on a hydrophobic supporting body. The undercoating layer contains a hydrophilic binder and silica in a weight ratio of the hydrophilic binder to silica less than 1. As the hydrophilic binder contained in the undercoating layer, protein is generally used and gelatin can be suitably used. But, a synthetic, semisynthetic or natural polymer is substituted for a part or the whole of gelatin. Suitable silica in the undercoating layer is anion-type silicon dioxide and colloidal silica has surface area of at least 300 m<2> /g. The weight ratio of the hydrophilic binder to silica is less than 1 and suitably is 0.25-0.5. |
