| 摘要 |
PURPOSE:To prevent deterioration in performance even after long-term storage under high temperature and high humidity, by adding a diazo compound and acid phosphite by 1 to 50 wt.% based on this compound. CONSTITUTION:A photosensitive diazo compound insoluble in water but soluble in usual organic solvents, preferably a diazo resin represented by a condensation product of p-diazodiphenylamine and HCHO, is dissolved in a proper solvent. To this solution is added phosphite acid in an amount of 1 to 50, preferably 4 to 30 % wt. based on the diazo compound directly or in the form of solution dissolved in solvent. To this photosensitive composition are added binder, and when needed, dye, pigment stabilizer, plasticizer, and filler. A photosensitive lithographic printing plate using this, on exposure to an active light through a transparent negative image film, undergoes change in its exposed portions, resulting in forming difference in a degree of swelling in a developing solution made of a weak alkaline water between the exposed and unexposed portions. |
