| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a photosensitive composition having high sensitivity and good preservability by using a specified polymer, a diazido compound and a near IR absorbing dye. SOLUTION: The photosensitive composition comprises a polymer having repeating units of the formula, a diazido compound and a near IR absorbing dye. In the formula, R1 is a substitutable arbitrary group or atom and (p) is an integer of 1-3. The polymer is easily synthesized by bringing partially or perfectly saponified polyvinyl alcohol into acetalizing reaction with hydroxybenzaldehydes only or these and other aldehydes in the presence of an acid catalyst. Though any dye may be used as the near IR absorbing dye when it has absorption in the near IR region, the sensitivity of the composition as a photosensitive material may largely depend on the dye. A high output semiconductor laser having oscillation wavelength in the near IR region is particularly preferable as a light source and the surface of a printing plate material is preferably exposed with light having more than several mW/cm2 energy.</p> |
