| 摘要 |
PURPOSE:To enhance printing resistance of a letterpress and to facilitate its manufacture by using a parabanic acid copolymer to manufacture the letterpress. CONSTITUTION:The letterpress is formed with a film of the parabanic acid copolymer having repeating units each represented by formula I or II in which R1 is a divalent group, preferably, having at least >=2 optionally substituted phenylene units on the main chain, and R2 is a divalent group, preferably, having at least one optionally substituted phenylene group on the main chain. The letterpress is manufactured by forming an alkali-resistant photosensitive resin layer (B) on a film A, patternwisely exposing the layer B, developing it to disclose a part of the surface of the film A, etching said disclosed surface of the film A with a liquid mixture containing an alkaline component and hydrazine, and peeling the remaining layer B. |
