To perform lithographic printing having excellent ink repellency and high printing durability by introducing specific fine particles to a hydrophilic expansion layer on a base plate.
Surface hydrophilized fine particles are contained in a hydrophilic swelling layer formed on a base plate. As the particles, inorganic or organic fine particles are used. 5 to 60 pts.wt. of the particles having a mean primary particle size of 0.005 to 5 μm are preferably contained in 100 pts.wt. of solid content of the swelling layer. And, it is also preferable to contain both the organic particles having the mean primary particle size of 0.007 to 0.1 μm and the inorganic particles having the mean primary particle size of 0.1 to 1 μm. Thus, more excellent ink repellency and wider dampening water allowing range are not only obtained, but also inking properties of printing elements become higher, and wet, adhesive of interface between water swelled part and the particles is upgraded to improve printing durability.
GOTO KAZUOKI
FUJIMARU KOICHI
