POSITIVE TYPE PHOTOSENSITIVE MIXTURE AND PHOTOSENSITIVE COPYING MATERIAL AND MAKING OF RELIEF IMAGE

PURPOSE: To make it possible to obtain high sensitivity, good resolution and good developer resistance by incorporating compds. (coupling agents) which can form azo coupling with oquinonediazide into a photosensitive mixture. CONSTITUTION: The photosensitive mixture contains the compds. (coupling agents) which can form the azo coupling with the oquinonediazide. The methylene active compds. having at least one piece of substituents to accelerate electrophilic substitution on a ring and/or arom. and heteroarom. compds. are used as the compds. which generate the azo coupling with the o-quinonediazide. Then, the coupled o-quinonediazide is made into a soln. to the sufficient extent in the actually exposed parts and, on the other hand, the product thereof has no possibility of being flushed away in such a manner that the resolution and developer resistance of the non-exposed coating are not substantially lessened by a developer in the non-exposed parts. As a result, the photosensitive mixture used for production of offset printing plates is obtd.