| 摘要 |
PURPOSE:To obtain a lithographic plate not suffering background stains and superior in sensitivity to fat or grease on image parts by treating a lithographic plate material with an aqueous solution containing phytic acid and/or its water- soluble salt and aminobenzenesulfonic acid and/or its water-soluble salt, and subjecting the plate material to a burning treatment. CONSTITUTION:The photosensitive lithographic plate having a support of an Al plate or the like is treated between a development step and after the burning treatment step with a processing solution containing free phytic acid and/or its water-soluble salt, such as Na, K, NH4, or NH2 salt, in a amount of 1-40wt%, preferably, 3-30wt%, and aminobenzenesulfonic acid and/or its water-soluble salt in an amount of 0.1-20wt%, preferably, 0.3-10wt%, when needed, a surfactant, various salts, alkalis, and the like, and plate is subjected to patterning treatment in the presence of said compound, thus permitting the obtained lithographic plate not to suffer background stains and to be enhanced in fat and grease sensitivity of the image parts. |
