A negative planographic printing plate precursor for heat-mode exposure systems, which has, on a support, a photosensitive layer containing: (A) a light-to-heat conversion agent; (B) a polymerizable unsaturated group-having compound; and (C) an onium salt having a counter anion with a valency of at least 2. The precursor is capable of being exposed with an IR laser for image formation thereon. The onium salt may be, for example, a diazonium salt, iodonium salt or sulfonium salt. The counter anion has at least two anionic sites which may be the same or different, and the anionic structure is preferably divalent to hexavalent.
一种负性平版印刷版前体,适用于热模式曝光系统,其在支撑体上具有一层光敏层,包含:(A)光热转换剂;(B)可聚合不饱和基化合物;和(C)带有价态至少为2的阴离子盐。该前体能够通过红外激光曝光形成图像。阴离子盐可以是重氮盐、
碘盐或
硫鎓盐。计数器离子具有至少两个离子位点,可以相同或不同,并且阴离子结构最好是二价到六价的。