| 摘要 |
PURPOSE:To obtain the planographic printing plate having an excellent plate inspecting property at all times by incorporating water, dye and chelate agent into the dyeing liquid for dyeing image parts after developing of the waterless planographic printing plate thereby maintaining the dyeing concn. at the time of running. CONSTITUTION:The water, dye and chelate agent are incorporated into the dyeing liquid for dyeing the image parts obtd. after the development of the waterless planographic printing plate. A triphenyl methane system, xanthene system, oxadine system, thazine system, monoazo system, and quinoneimide system are preferably as the dye and the amt. of the dye to be added is 0.05 to 3wt.%, mor preferably 0.1 to 1wt.% of the weight of the dyeing liquid. The chelating agent to be used here is preferably a compd. which forms a chelate compd. by making coordinate bond with the metallic ions, prescribed polysulfones, polyphosphates, oxyacid, and aminopolycarboxylic acids. The printing plate which obviates the degradation in the dye density during running and has the always stable dyeing density is obtd. in this way. |
