| 摘要 |
PROBLEM TO BE SOLVED: To obtain a planographic printing plate having high ink repellency, ensuring a wide acceptable range of dampening water and having high durability in printing by containing titanium dioxide whose surface is made hydrophilic into a hydrophilic swellable layer. SOLUTION: The planographic printing plate has at least a hydrophilic swellable layer on the substrate and the hydrophilic swellable layer contains titanium dioxide whose surface is made hydrophilic. The titanium dioxide is titanium dioxide granulated by a sulfuric acid method, a chlorine method, etc., or titanium dioxide produced by pulverizing and classifying the granulated titanium dioxide. Specifically, the titanium dioxide is, e.g., anatase type or rutile type titanium dioxide. The pref. average primary particle diameter of the titanium dioxide is 0.005-5μm, in particular 0.007-1μm. The pref. amt. of the titanium dioxide is 5-60 pts.wt., in particular 10-40 pts.wt., based on 100 pts.wt. solid content of the hydrophilic swellable layer. |
