| 摘要 |
PROBLEM TO BE SOLVED: To provide an offset printing method satisfying a simple plate-making property using no developing soln., printing image quality backed by the discrimination property of the image part and non-image part of a printing surface and sufficient printing durability. SOLUTION: In an offset printing method, a printing original plate having a metal, which has high temp. hydrophilicity developing characteristics, formed on its surface is made hydrophobic and the surface thereof is subsequently imagewise heated at a high temp. hydrophilicity developing temp. to form a hydrophilic/hydrophobic region imagewise distribution and an electroless plating aq. soln. containing a water soluble metal compd. an a reducible compd. and prepared so that the oxidation potential of the reducible compd. is baser (lower) than the reduction potential of the water soluble metal compd. is brought into contact with the printing original plate. A metal thin layer is imagewise formed on a hydrophilic region by electroless plating and hydrophilizing treatment is further applied to a hydrophobic region and the printing original plate is brought into contact with ink to form a printing surface receiving ink on the region having the metal thin layer to perform printing. |
