| 摘要 |
PURPOSE:To obtain a printing plate capable of water development and having good reproducibility of minute picture lines by using a photosensitive composition consisting of the three components of specified polyamide, specifically saponified polyvinyl acetate and a monomer having >=1 acryloyl or methacryloyl group in a molecule. CONSTITUTION:A photosensitive composition consists of a homopolymer or a copolymer of amide having 50-100wt% unit shown in the formula I (where, R1, R2 are <=3C alkyls, (n) is an integer of 5-11) and 50-0wt% unit shown in the formula [(n) is the same as previously described], 30-80wt% partially saponified polyvinyl acetate having 60-99mol% saponification grade, and 15-70wt% compound having at least >=1 acryloyl or methacryloyl group and preferably OH group in a molecule. To the solution of said photosensitive composition, if necessary, additives such as photosensitizer, heat stabilizer or the like are added to form a photosensitive layer by casting on a polyester film or the like and drying. Using this photosensitive material, a relief printing form plate capable of reproducing sharply almost minute parts of halftone dot and fine lines in a copy film and having excellent printing resistance is obtd. by water development. |
