| 摘要 |
PURPOSE: To obtain the solution for surface treating of the planographic printing plate superior in ink receptivity and solution stability by containing at least one kind of polystyrenesulfonic acid having an average molecular weight less than a specified value. CONSTITUTION: The surface treating solution for the planographic printing plate having an anodized and roughened aluminum support and a physical development nucleus layer and a photosensitive silver halide emulsion layer formed on the support contains at least one kind of polystyrenesulfonic acid having an average molecular weight of <=20000, preferably, 1000 to <=20000. This printing plate surface treating solution can contains a salt having a buffering effect, such as phosphates, carbonates, citrates, or nitrates, and a viscosity increasing agent, such as carboxymethyl cellulose or hydroxymethylcellulose, alone or in combination of 2 or more kinds. It is necessary that an organic compound having a mercapto or thione group is used for this solution in order to promote the ink receptivity of an image silver. |
