| 摘要 |
PROBLEM TO BE SOLVED: To stably prepare a printed article of a high grade by using a water- soluble printing ink when a printing is performed by a lithographic printing plate equipped with at least a hydrophilic swelling layer on a base. SOLUTION: When a printing is performed by a lithographic printing plate wherein a hydrophilic swelling layer is made an ink repelling layer, the printing is performed by using a water-soluble printing ink. Thus, a sufficient ink repelling property is manifested, and also, even when water existing on the plate surface is excessive, the ink repelling layer can be swollen with water, and a sufficient water holding property can be ensured, and a printed article of a high grade can be produced. For the water-soluble printing ink, an ink composition which contains 5 wt.% or higher of a water-soluble organic solvent, and 30 wt.% or lower of a water-insoluble organic solvent is suitable, and especially preferably, no water-insoluble organic solvent is contained in the water-soluble printing ink. Also, a non-picture line section comprising the hydrophilic swelling layer preferably has a water absorption amount of 1-50 g/m2, and a water swelling rate of 50-2000%. |
