GB1454030A - Dual-nature screen process - Google Patents

Abstract

1454030 Colour screen containing colour coupler GAF CORP 21 Feb 1974 [2 March 1973] 8036/74 Heading G2C A colour screen of one to three colours comprises an array of red or green or blue coloured oil droplets each droplet containing a non-diffusing filter dye having one of the primary colours and a colourless colour coupler fast to diffusion in aqueous gelatine matrices having a pH of 6À0 to 7À0 but diffusible through such aqueous gelatine matrices at a pH higher than 7À0 and capable of forming non- diffusing cyan or magenta or yellow dyes, respectively, on coupling with oxidized p-phenylenediamine colour developing agent, the micro areas possessing red or green or blue filtering action being exactly those containing cyan or magenta or yellow colour couplers, respectively. The colour screen may comprise an adjacent panchromatic silver halide emulsion layer and an image may be formed by exposing the emulsion through the screen, developing the emulsion with an appropriate colour developer of alkaline pH while the emulsion is in contact with a receiving element to which the colour couplers in the screen in the unexposed areas transfer and forming indoaniline or azomethine dyes in the receiving layer from the transferred colour coupler, by coupling with a paraphenylene diamine colour developer in the presence of an oxidizing agent. The receiving element may be separated from the panchromatic emulsion and screen or may remain intact for viewing. The screen and panchromatic emulsion may form part of a film unit which also comprises a rupturable container containing processing composition, an image-receiving layer and optionally an opaque layer or layers see Figs. 8-15 (not shown). The yellow, cyan and magenta couplers specified are x-benzoyl-o-methoxyacetanilide, N-(α-acetamido-phenethyl)-1-hydroxy- 2-naphthamide and 1-(2,4,6-trichlorophenyl)-3-pnitroanilino-2-pyrazolin-5-one, respectively.