| 摘要 |
PURPOSE:To obtain a diazo copying developing soln. capable of reducing fading of an image and retaining color tone at the time of copying for a long period by incorporating an alkali agent, a neutral diluent, thiourea and a specified compd. as a photofading inhibitor, each in a specified proportion. CONSTITUTION:An org. base, such as monoethanolamine, morpholine, or guanidine, is suitable for an alkali agent to be used. One or a mixture of optional combination of polyol, such as ethylene glycol or diethylene glycol, ether, such as ethylene glycol monomethyl ether, are used for a neutral diluent. Further, thiourea and a compd. represented by the formula (Y is S, alkylene, or methylene; R1 is 1-6C alkyl; and R2 is 1-5C alkyl) are used as a photofading inhibitor for the present developing soln. each in an amt. of 0.01-20wt% of the total amt. and an a thiourea to said compd. ratio of 4:6-1:9. As a result, fading of both of image parts and nonimage parts can be restrained. |
