FREMGANGSMADE TIL FREMSTILLING AF MONSTERTRYK OG EMNER FREMSTILLET EFTER DENNE FREMGANGSMADE

1519332 Photographic processes KOLLMORGEN CORP 7 July 1975 [11 July 1974] 28498/75 Addition to 1394889 Heading G2C Metal images are produced by imagewise exposing a material comprising a support coated with a solution of pH between 2 and 4À1 containing (a) copper halide in an amount of between 0À9 and 25 milliequivalents of halogen per litre (i.e. 0À1- 2À5 g.p.l. of copper halide), (b) a reducible salt of a non-noble metal containing anions other than halide ions, (c) a secondary reducer which alone is incapable of reducing (b); and (d) a radiationsensitive compound which alone or with (c) is capable of reducing (b) on exposure, the exposure producing nuclei and applying a physical developer to deposit a metal image on the nuclei. Specified compounds (d) are ferric salts, dichromates and preferably anthraquinone disulphonic acid disodium salt. Copper acetate is the preferred reducible salt (b) and sorbitol is the preferred reducer (c) but other reducible salts and secondary reducers specified in Parent Specification may be used. The use of copper halide in the specified amount and at the specified pH range produces more stable metal images than Parent Specification. The metal image may be reinforced by subsequent electrolytic metal deposition.