PHOTOSENSITIVE LITHOGRAPHIC PLATE

PURPOSE:To obtain the titled lithographic plate having superior chemical resistance and superior printing resistance and developable in a weak alkaline water, by forming on a support a photosensitive layer composed of a specified compsn. of photocross-linkable polyester, an ethylenically unsatd. compd., a photopolymn. initiator, and an aliphatic carboxylic acid. CONSTITUTION:The photocross-linkable polyester is prepared having (A) aromatic dicarboxylic acid units each having formula I [(m), (n) are each 0 or 1], (B) dicarboxylic acid units each having sulfonate salt, and (C) diol units having formula II (formula III is a hydrogenated benzene ring; R , R are each 2-4C alkylene; R , R are each 1-6C alkyl; (r), (s) are each 0-3; and (t) is 0 or 1). The intended photosensitive lithographic plate is obtained by forming on a support a photosensitive layer consisting of said photocross-linkable polyester, an ethylenically unsatd. compd. having plural additionally polymeriable terminal unsatd. double bonds, a photopolymn. initiator, and aliphatic carboxylic acid or acid anhydride contg. plural carboxylic acids.