Light-sensitive 1,2 quinone diazide containing mixture and light- sensitive copying material prepared therefrom wherein imaged produced therein is visible under yellow safety light

摘要

Disclosed is a light-sensitive mixture comprising (a) a 1,2- quinonediazide or a mixture of (a.sup.1) a compound forming an acid on exposure and (a.sup.2) a compound having at least one C--O--C bond cleavable by acid; (b) a water-insoluble binder soluble in aqueous- alkaline solutions; (c) an organic compound forming an acid on exposure of the general formula I ##STR1## in which X is a single bond or one of the groups CO, SO.sub.2, N=N or CR.sup.7 R.sup.8, R.sup.1, R.sup.2, R.sup. 3 and R.sup.4 are hydrogen atoms, halogen atoms or nitro groups, with not more than two of these radicals being hydrogen atoms and at least one thereof being a nitro group, R.sup.5 and R.sup.6 are hydrogen atoms or 1, 2-naphthoquinone-2-diazide-4-sulfonyloxy radicals, with R.sup.5 and R.sup. 6 being always different from each other, and R.sup.7 and R.sup.8 are hydrogen atoms or lower alkyl radicals, and (d) an azo dyestuff containing at least one nitro group in the molecule. Also disclosed are printing plates and photoresists prepared with the light-sensitive mixtures.