| 摘要 |
PURPOSE:To provide a desensitizing agent for use in planography which is free of toxicity or other defects of a conventional desensitizing agent and the quantity of which can be easily controlled, by incorporating a water-soluble surface-active organometallic compound into the desensitizing agent. CONSTITUTION:The water-soluble surface-active organometallic compound used as an effective component is a water-soluble surface-active organic compound containing a metal such as Si, Ti, Ce, Zr and Sn. The organometallic compound is used in an amount of 0.0005-5wt% based on the amount of the desensitizing agent, preferably, 0.001-2.0wt%, and such compound may be used either singly or in combination. Further, a water-soluble high molecular weight compound may be added, and if required, a wetting agent for suppressing drying and providing a favorable usability may be added. Where calcium ion or the like contained in city water or well water used for diluting the desensitizing agent has an adverse effect on printing, the problem can be solved by adding a chelate compound to the desensitizing agent. Further, a coloring agent, a preservative or the like is added. |
