| 摘要 |
Photopolymeric letterpress printing plates which are to be developed with water or water/alcohol mixtures after imagewise exposure and have, arranged one on top of the other on a dimensionally stable substrate, a layer (A) which may be bonded to the dimensionally stable substrate by an adhesion-promoting layer and is crosslinkable by actinic radiation, a layer (B) which is sensitive to IR radiation and, if required, a parting layer arranged between layer (A) and layer (B), and a peelable protective film applied to the layer (B), are produced by a process in which the layer (A) contains a mixture of at least one polymeric binder which is soluble or dispersible in water or water/alcohol mixtures, copolymerizable ethylenically unsaturated organic compounds which are compatible with the polymeric binder and a photoinitiator, the layer (B) sensitive to IR radiation has an optical density >=2.5 in the actinic range and contains a film-forming polymeric binder which is soluble or dispersible in water or water/alcohol mixtures and a substance which is finely distributed in this binder and absorbs IR radiation, and the layer (B) sensitive to IR radiation is structured by laser ablation and is then exposed uniformly to actinic radiation, developed and dried in a conventional manner.The novel process is suitable for the production of letterpress printing plates.
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