DAMPENING-WATERLESS PHOTOSENSITIVE PLANOGRAPHIC PRINTING PLATE

摘要

PURPOSE:To obtain the dampening-waterless planographic printing plate which has a primer layer and exhibits an excellent exposing visible image property by incorporating a specific dye into a photosensitive layer. CONSTITUTION:The primer layer, the photosensitive layer and silicone rubber layer are formed in this order on a base and the dye changing in hue angle (H) by >=20 deg. with a change in pH by >=1 is incorporated into the photosensitive layer. Since the hue angle changes largely in this case, the easily visible and sufficient exposing visible image property is exhibited. This effect is particularly remarkable with the negative type dampening waterless planographic printing plate which is particularly small in pH change. The dampening-waterless planographic printing plate which has the primer layer and is good in the exposing visible image property is obtd. in such a manner.