| 摘要 |
PURPOSE:To obtain a high-fineness pattern securely, by alternately stack a plurality of copper layers and a plurality of nickel layers on a base layer. CONSTITUTION:A plate material 1 for intaglio offset printing comprises an iron layer 2 as a base, on which a plurality of copper layers 2 and a plurality of nickel layers 4 are alternately stack. The upper copper layer 3 and the upper nickel layer 4 constitute a plate face forming layer part 5. The copper layer 3 constituting the uppermost layer is subjected to the first etching, after a layer of a resist agent 6 is patterned into a predetermined pattern. The etching produces plate face areas 7 a alignment mark areas 8 in the uppermost copper layer 3. The face area 7 are protected with a protective coating agent 9, and the nickel layer 4 in the alignment mark areas 8 is etched with an etching solution containing sulfuric acid as a main constituent. Then, the copper layer 3 exposed upon this etching is etched with a ferric chloride solution, to obtain a printing plate 10 in which ink cells 8a in the alignment mark areas 8 are deeper than ink cells 7a in the plate face areas 7. |
