Photographic elements and photopolymerization therewith

984,456. Photographic elements and photopolymerization therewith. GENERAL ANILINE & FILM CORPORATION. July 13, 1961 [Aug. 10, 1960], No. 25473/61. Heading G2C. The elements comprise a support bearing a coating of colloidal carrier containing an ethylenically unsaturated monomer, a radiation-sensitive ferric salt and a photopolymerization speed increasing reducing agent readily oxidized by hydrogen peroxide. The elements are similar to those of Specification 883,811 except for the presence of this agent,the effect of which is to give a speed increase of up to ten times. Thirteen examples are provided the first of which is a control, not an example of the elements claimed, in which aqueous gelatin with acrylamide, N, N1- methylenebis-acrylamide, glycerin and ferric ammonium citrate are formed into a coating on a paper base, exposed and processed in 1% hydrogen peroxide to give a resist;and then other examples describe the inclusion of sodium-sulphite,-bisulphite,- hydrosulphite, -thiosulphate, glyoxylic acid, glyoxalsodium bisulphite, glycine,mercapto-acetic acid sodium salt as speed increasing reducing agents to the formulation of the control. Example X varies the procedure by including cumene hydroperoxide in the element and omitting hydrogen peroxide from the processing liquid. Extensive lists of alternative materials for use in the procedure are provided,and the final products may be black and white prints, dyed prints or printing plates of various types.