| 摘要 |
PURPOSE:To obtain a lithographic original plate capable of both of positive and negative workings and superior in stability with the lapse of time by using a photosensitive layer contg. an o-quinonediazide compd., a spiropyran compd., and a benzothiazole deriv. CONSTITUTION:A lithographic original plate is obtained by forming a potosensitive layer on a support by coating it with a styrene-maleic acid copolymer or the like as a binder, when needed, and a mixture of (A) 1pt.wt. o-quinonediazide compd., such as 2,2'-dihydroxydiphenyl-bis(naphthoquinone-1,2-diazide-5- sulfonic acid ester, (B) 0.005-1pt.wt. spiropyran compd. represented by formula I , and (C) 0.01-0.5pt.wt. benzothiazole deriv. represented by formul II. In formulae I and II, X is formula III, -S-, or -Se-, and R1-R4 are each H, -CH3, -OCH3, -Cl, or the like. |
