Patent ID: 7723013

Claim:
A negative-acting photolithographic printing plate precursor comprising: a substrate having a surface; and a negative-acting photosensitive composition on the surface, wherein the photosensitive composition comprises an acetal polymer, an infrared absorbing dye or pigment, a crosslinking agent comprising amino compounds having at least two functional groups for the acetal resin and a photosensitive chemical acid progenitor, and the acetal polymer has within its backbone a structure comprising a moiety of the formula: wherein: R 1 is —C n H 2N+1 where n=1-12; R 2 is wherein R 4 =—OH; R 5 =—OH or —OCH 3 or —Br or —O—CH 2 —C═CH; and R 6 =Br or —NO 2 ; R 3 =—(CH 2 ) a —COOH or —C═CH or where R 7 =COOH, —(CH 2 ) a COOH or —O—(CH 2 ) a COOH, and a =0 or 1, and m=about 5-40 mol %, g=about 10-60 mole %, o=0-20 mole %, p=1-20 mole %, and q=5-50 mole %, preferably 15 to 40 mole %.