| 摘要 |
PROBLEM TO BE SOLVED: To obtain a printing plate protective agent capable of rendering a nonimaging part insensitive to greases and free from occurrence of dropout of prints even in the case of a long time storage and kept high in stability by incorporating an aliphatic saturated chain hydrocarbon having branched hydrocarbons specified in a carbon number range in the emulsified printing plate protective agent for the lithographic printing plate. SOLUTION: The emulsified printing plate protective agent for the lithographic printing plate contains one or more kinds of combinations of the aliphatic saturated chain hydrocarbon with the branched hydrocarbons in the range of 18-36 carbon number in an oil phase. These branched hydrocarbons are embodied by methyl, ethyl, n-propyl, and isopropyl groups and the like, thus permitting the obtained plate protective agent for the lithographic printing plate to render a nonimaging part insensitive to greases and to be free from occurrence of drop-out of prints even in the case of a long time storage and kept high in stability. When a sponge or cotton tampon or the like is used for this agent, the printing plate can be easily subjected to this agent, and it can be used, while maintaining stability for a long period against mixing of the component of the developing solution. |
