PHOTOSENSITIVE STRUCTURAL BODY FOR FLEXOGRAPHIC PRINTING PLATE

摘要

A photosensitive structural body for a flexographic printing plate comprising a polyester film as a supporter (B), a photosensitive elastomer composition (C) and, placed between them, an adhesive layer (A), characterized in that the composition (C) comprises (a) 50 wt % or more of at least one thermoplastic elastomer comprising a monovinyl-substituted aromatic hydrocarbon and a conjugated diene, (b) 5 to 40 wt % of at least one diene-based liquid rubber, (c) 1 to 20 wt % of at least one ethylenically unsaturated compound having two unsaturated bonds in a molecule thereof, and (d) 0.1 to 3 wt % of at least one photopolymerization initiator, and further in that (1) the average proportion of vinyl bonds in the conjugated diene segments of the thermoplastic elastomer is 10 to 20 mole % and (2) the liquid rubber has a number average molecular weight of 500 to 5,000 and an average proportion of vinyl bonds of 50 to 70 mole %.