| 摘要 |
PURPOSE:To obtain a waterless planographic printing plate material enabling to erase an image, to form an image and to print an arbitrary number of times, by a method wherein a printing plate material having a silicone layer repellent to an ink and adhesive to a toner is used, and a specified organic solvent is used for erasing an image formed on the printing plate. CONSTITUTION:A material wherein a silicone layer repellent to an ink and adhesive to a toner is provided in a film thickness of 0.5-5mum is used as a waterless planographic printing plate material, and an image is formed thereon by using a toner such as a modified epoxy resin or a polyester to obtain a printing plate. The silicone layer may be formed of, e.g., a (metal-containing) silicone composition comprising a dimethylsiloxane bond as a main constituent and comprising a polar group or a phenyl group in a side chain. With the printing plate thus obtained, a part or the entire part of an image formed on the printing plate can be wiped away with an organic solvent having a carbonyl group, an ether group or a halogen atom, after or before printing. |
