ELASTOMER CONSTITUENT AND PHOTOSENSITIVE COMPOSITION MAKING USE OF THE SAME

摘要

An elastomer constituent that is suitable for use in a printing plate material; and a photosensitive composition making use of the elastomer constituent that excels in laser workability performance, image developability, clear printing even with respect to small letters and, with a hydrophilic polymer added thereto, water developability. There is provided an elastomer constituent comprised mainly of a block (co)polymer containing as indispensable components a polymer block composed mainly of at least two aromatic vinyl compounds, a copolymer block of specified structure consisting of a polymer block composed mainly of at least one conjugated diene and a polymer block composed mainly of one or more conjugated dienes wherein one or more aromatic vinyl compound polymer blocks may be contained. Further, there is provided a photosensitive composition comprising the above elastomer constituent, a photopolymerizable unsaturated monomer and a photopolymerization initiator.