| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a negative type CTP (Computer to Plate) having the excellent resolution and plate wear in the printing area of a press plate obtained by forming a picture latent image by the heat generated by irradiation of a thermosensitive layer with a laser beam, then by developing the image by an alkaline-soluble developing solution with a thermosensitive planographic printing plate formed with the thermosensitive layer consisting of an alkaline-soluble polymer on the surface of a support having a hydrophilic surface. <P>SOLUTION: The thermosensitive planographic printing plate formed with the thermosensitive layer consisting of the alkaline-soluble polymer on the surface of the support having the hydrophilic surface is characterized by the advance contact angle (θ<SP>f1</SP>) of the surface of the thermosensitive layer and water of 25°C ranging from 70 to 110°, the retreat contact angle (θ<SP>b2</SP>) of the surface of the thermosensitive layer after heating for 3 minutes at 150°C and the water of 25°C greater than the retreat contact angle (θ<SP>b1</SP>) of the surface of the thermosensitive layer prior to the heating and the water of 25°C, and the difference (θ<SP>b2</SP>-θ<SP>b1</SP>) of the retreat contact angle before and after the heating greater than 1° and smaller than 40°. <P>COPYRIGHT: (C)2004,JPO |
