Patent GB-1345071-A (GB)
IPC: G03C8/08
Filed: 1971-07-22
Abstract: 1345071 Photographic dye diffusion transfer EASTMAN KODAK CO 22 July 1971 [24 July 1970] 34476/71 Heading G2C  A photographic assemblage comprises a transparent support coated with an imagereceiving layer having thereon a photo-sesitive element comprising at least one photo-sensitive silver halide emulsion layer, each said silver halide emulsion layer having associated therewith a non-diffusible dye image-providing material capable of reacting with oxidized developing agent to produce a diffusible dye, a top sheet superposed over the outermost layer of the photo-senstive element i.e. farthest from the transparent support, a first rupturable container positioned in the assemblage so that when a compressive force is applied to it discharge of its contents between the top sheet and the outermost layer of the photo-sensitive element is effected, and a second rupturable container positioned in the assemblage so that when a compressive force is applied to it discharge of its contents between the image-receiving layer and the innermost layer of the photo-sensitive element (i.e. nearest the transparent support) is effected, the assemblage containing a developing agent; one of the rupturable containers containing an opacifying agent and the other rupturable container containing an alkaline aqueous processing composition. The developing agent may be an aromatic primary amine colour developing agent and the photo-sensitive element may comprise red-, green- and blue-sensitive silver halide emulsion layer having associated therewith cyan, magenta and yellow non-diffusible couplers respectively, which produce diffusible dyes on coupling. These couplers may be in contiguous layers to their respective silver halide emulsions. The top sheet may be transparent and one rupturable container may contain an alkaline aqueous processing composition containing an opacifying agent and the other rupturable container an opacifying agent or the first rupturable container may contain an opacifying agent and the second rupturable container an alkaline aqueous processing composition, the assemblage containing an opaque reflecting layer between the image-receiving layer and the photo-sensitive element. The top sheet may be opaque, the first rupturable container contain an alkaline aqueous processing composition and the second rupturable container an opacifying agent. The assemblage may contain a pH-lowering layer. The silver halide emulsion layers may be direct positive. The silver halide emulsion layers may contain non-diffusible development-inhibitor-releasing (DIR) couplers and have contiguous hydrophilic colloid layers containing a water-insoluble metal salt which is developable by an aromatic primary amino colour developing agent without exposure to light and a non-diffusible coupler which produces a diffusible dye on coupling. The developable layer may contain silver thiocyanate and physical development nuclei. In another embodiment the silver halide emulsion layers contain colour couplers which form immobile products on coupling and adjacent each silver halide emulsion layer a hydrophilic polymer spacer layer and a nuclei layer containing physical development nuclei and a non-diffusible coupler which produces a diffusible dye on coupling, the assemblage containing an aromatic primary amino colour developing agent and a silver halide solvent. The rupturable containers may have a common wall.