| 摘要 |
PURPOSE:To maintain a favorable ink-adhering property, by a method wherein a layer comprising an organic substance with lower limits of molecular weight and boiling point thereof specified is provided on a printing surface of a planographic printing plate not requiring damping water which plate has a silicone rubber layer backed with a base as a non-image part. CONSTITUTION:A layer comprising an organic substance having a molecular weight of not smaller than 100 and a boiling point of not lower than 200 deg.C is provided on the printing surface of the planographic printing plate not requiring damping water which plate has the silicone rubber layer backed with the base as the non-image part. The silicone rubber layer has a thickness of about 0.5- 100mum, preferably about 0.5-10mum, consisting mainly of a linear organic polysiloxane having a molecular weight of several thousands to several hundreds of thousands, and a cross-linking agent ordinary used in a so-called cold-curing type silicone rubber, such as acetoxysilane, is incorporated therein. The molecular weight of the organic substance is not lower than 100, preferably 10<3>-10<6>, and the boiling point must be not lower than 200 deg.C, and is preferably not lower than 300 deg.C. High polymer such as a (meth)acrylic acid base polymer may be mentioned as an example of the organic substance. |
