| 摘要 |
PURPOSE:To favorably erase unnecessary image parts by using an erasing soln. composed of a water-soluble org. solvent contg. an alkali-soluble acidic substance and an anionic surfactant, as an erasing soln. for erasing unnecessary image parts. CONSTITUTION:A photosensitive lithographic plate obtained by forming a photosensitive layer contg. an o-quinonediazide compd. or the like on a support is imagewise exposed to form a printout image. A good image freed of unnecessary image parts is obtained by spreading an erasing soln. composed of an water- soluble org. solvent, such as ethanol, contg. an alkali-soluble acidic substance, such as lactic acid, in an amt. of 0.1-10wt% and an anionic surfactant, such as alkylbenzenesulfonate, in an amt. of 0.01-10wt% on unnecessary image parts, such as register marks, and developing them with a developing soln., such as an aq. soln. of NaOH. |
