Photosensitive planographic printing plate precursor

摘要

A photosensitive planographic printing plate precursor comprising an aluminum substrate surface treated such that the center line surface roughness thereof (Ra) is in a range of from 0.30 mum or more to 0.55 mum or less and a photosensitive layer provided on the substrate and comprised of a photosensitive composition containing (a) a water-soluble or water-dispersible polymer, (b) a monomer or oligomer having at least one ethylenically unsaturated double bond capable of photopolymerization, and (c) a photopolymerization initiation system having lambdmax in a range of from 330 nm or more to 375 nm or less such that the light absorbance A at lambdmax and the absorbance B at 400 nm fulfill a relationship of B/A<0.1. A preferred example of (a) the water-soluble polymer is a polymer containing a sulfonic acid (salt) group.