| 摘要 |
PURPOSE:To improve contamination resistance, printing resistance and build-up property by developing a photosensitive material with an alkali aq. soln. substantially containing no org. solvent. CONSTITUTION:A photosensitive planographic printing board consists of a supporting body and a photosensitive layer containing a diazo compd. and an oleophilic polymer compd. having acid value between >=30 and <=250 formed on the supporting body. This planographic printing board is exposed to light for a picture image and then developed with an alkali aq. soln. between PH>=7 and pH<12 which substantially contains no org. solvent. The diazo compd. is, for example, a diazo resin which is a condensate of an aromatic diazonium salt with an active carbonyl-contg. compd., especially with formaldehyde. The diazo resin is, for example, a diazo resin inorg. salt which is the reaction product, soluble in an org. solvent, of a condensate of p-diazodiphenylamine and formaldehyde or acetoaldehyde with hexafluoro phosphate or tetrafluoro borate. |
