| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain an alkali-soluble polymer which is suitable as a binder polymer for an image recording layer of a negative lithographic printing original plate generating no development dregs in a developer after developing; and a polymerizable composition using the polymer. <P>SOLUTION: The alkali-soluble polymer has structural units each represented by formula (1) and having a side chain having a carboxyl group or groups. When dissolved in an aqueous alkali solution with a pH of 10 or higher and left as it is at ordinary temperature for 60 days, the alkali-soluble polymer does not cause precipitation. Preferably, the polymer has side chains each having a functional group represented by formula (2) and capable of changing into an acid group by alkali hydrolysis. In formula (1), R<SP>1</SP>is H or methyl; and R<SP>2</SP>is an (n+1)-valent organic linking group having an ester group represented by -O(C=O)-. In formula (2), X<SP>1</SP>is a protective group hydrolyzable by an aqueous alkali solution with a pH of 10 or higher. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
