Patent ID: 6911299

Claim:
A method for preparing a lithographic printing plate comprising the steps of imagewise light-exposing to infrared radiation, a presensitized plate for use in making a lithographic printing plate, said presensitized plate having an image-forming layer which comprises an IR-absorbing agent, and developing the light-exposed plate with an alkaline liquid developer comprising at least one selected from the group consisting of the compound represented by the following formula (I), the compound represented by the following formula (II), acetylene alcohols and acetylene glycols R—OCH 2 —CH 2 O n H (I) wherein R represents an aromatic group or an aliphatic group represented by the formula: C p H 2p+1 or C p H 2p−1 (wherein p represents an integer from 6 to 20), and n represents an integer of 4 or more wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 may be the same or different, and each independently represents H or —CH 3 , and R 9 , R 10 , R 11 and R 12 may be the same or different, and each independently represents H, —CH 3 , —COR 13 or —CONHR 14 (wherein each of R 13 and R 14 represents an alkyl, aryl, alkenyl or alkynyl group), a represents an integer of from 2 to 12, b, c, d, e, f, g, h and i may be the same or different, and each independently represents 0 or an integer of from 1 to 300, and (b+f)(c+g)(d+h)(e+i)≠0.