| 摘要 |
PURPOSE:To enhance the printing resistance of a lithographic printing plate requiring no dampening water by forming a photoadhesive layer of lower sensitivity and that of higher sensitivity on the substrate side of a plate using a photosetting silicone layer and the separable sheet side, respectively. CONSTITUTION:On substrate 1 the first photoadhesive layer 2 of lower sensitivity and photosetting silicone layer 3 are laminated in this order, and the second photoadhesive layer 4 of higher sensitivity is laid on ultraviolet transmissive sheet 5 to form a separable sheet. This sheet and substrate 1 are closely contacted with layers 4, 3 inward and irradiated with light 7 through ultraviolet untransmissive image 6 to raise the bonding strength of the irradiated portion of layer 4, thereby bonding a layer 3 portion corresponding to the irradiated portion to the sheet 5 side. Sheet 5 is then separated from substrate 1 so that set silicone layer 3' and unset silicone layer 3 are left on sheet 5 and substrate 1, respectively, and substrate 1 is well irradiated with light to convert the unset silicone into set silicone layer 3' and bond layer 3' to substrate 1 very firmly. Thus, a printing plate is obtained. |
