| 摘要 |
PROBLEM TO BE SOLVED: To provide a developer and a developing method for giving a printing plate excellent in image quality, not causing surface stain in printing and excellent in printing resistance without heating a plate material before development when a negative type photosensitive planographic printing plate sensitive to infrared laser light is developed. SOLUTION: When a negative type photosensitive planographic printing plate sensitive to infrared laser light is developed with an alkaline developing solution, the developing solution for a negative type photosensitive planographic printing plate containing an alkali metal silicate, an alkali metal hydroxide and a tetraalkylammonium hydroxide is used as the alkaline developing solution. |
