| 摘要 |
PURPOSE:To effectively prevent the influence of oxygen in the image exposing stage without providing an oxygen barrier layer on the surface of a photosensitive layer and to obtain high printing resistance power of a lithographic printing plate by forming a photopolymn. initiator of a combination of respectively specific S-triazine trihalomethyl compd. and thioxanthone compd. CONSTITUTION:The photopolymn initiator of the photosensitive compsn. contg. (1) an ethylenic unstad. polymerizable compd., (2) alkaline water soluble or swellable and film formable polymer, (3) photopolymn. initiator and (4) diazo resin is constituted of the combination of the S-triazine trihalomethyl compd. expressed by formula (I) and the thioxanthone compd. expressed by formula (II). The amt. of the component (1) to be used is made 5-50wt% by the weight of the total compsn. and the amt. of the component (2) to be used is made 10-90%. The component (1) and the component (2) is used in a 0.5/9.5-5/5 range by weight. The ratios of the formula (I) and the formula (II) with regard to the total weight of the photopolymn. initiator are respectively made 80-20wt% and 20-80wt%. |
