Dry positive photopolymer imaging process involving heating and application of toner

Copolymers of glycidyl acrylate and allyl glycidyl ether and terpolymers derived from addition of glycidyl methacrylate to the polymerizable mixture, having an inherent viscosity within the range of about 0.09 to 0.28 and an epoxy equivalent of at least about 0.64 per 100 g. of polymer are provided which upon admixture with a catalyst which is a radiation-sensitive aryldiazonium salt of a complex halogenide, provides compositions suitable for use in a dry photopolymer positive imaging process. In the process, the polymer which is non-tacky at room temperature, together with the catalyst is applied to a substrate and exposed to an energy source for example, electromagnetic radiation through a transparency or mask. Following exposure, the coating is heated to the softening point of the unexposed portion of the coating and a powder or toner is applied thereto, the toner being adhered to only the tacky, non-exposed area of the coating, resulting in a pigmented image.