Photoimaging systems with cyclic hydrazides

U.S. 4,247,618. Photoimaging Systems with Cyclic Hydrazides. Dessauer, Rolf Firmani, Raymond A. (E. I. Du Pont de Nemours and Company). January 27, 1981 (Cl. 430/342 430/33). Appl. 

In DuPont s eyes, this appeared to conflict with the Dessauer patent U.S. 4,247,618 (Photoimaging Systems With Cyclic Hydrazides), which issued in 1/27/1981, since that clearly described the remarkable deactivation effect of this class of compounds, of which phenidone is the best known. In hme this possible interference was settled, and Fuji s Copiart-3 proof paper came onto the market. It had many attractive attributes speed, appearance, more versatility due to the lack of restricted imaging/fixing wavelengths, but it did not greatly impact the market for DYLUX proof paper. 

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