| 摘要 |
PURPOSE:To obtain a lithographic plate prevented from background stains and superior in lipophilicness of image parts by coating a photosensitive lithographic plate material imagewise exposed and developed with an aqueous solution containing a copolymer comprising specified repeating units or its salt and phytinic acid and/or its salt, and subjecting it to burning treatment. CONSTITUTION:The processing solution to be applied to the exposed and developed lithographic plate material before the burning treatment is an aqueous solution comprising the copolymer composed of at least one of each of the repeating units represented by formulae I and II, and their salts, preferably, in a I/II repeating units weight ratio of 9:1-7:3, and phytinic acid and/or its salt. In these formulae, R1 is H or the like, and each of M1 and M2 is H or the like. The copolymer has a molecular weight of, preferably, 2,000-8,000. |
