Patent GB-1335189-A (GB)
Title: Photographic silver halide products and diffusion transfer  processes
IPC: G03C8/08
Filed: 1970-11-26
Abstract: 1335189 Photographic silver halide products and diffusion transfer processes INTERNATIONAL POLAROID CORP 26 Nov 1970 [26 Nov 1969] 56270/70 Heading G2C A photographic product comprises a photosensitive element comprising a support carrying on one side at least two selectively sensitized silver halide layers each having associated therewith a compound providing as a function of development a dye image forming material and, between a pair of adjacent silver halide layers, an interlayer comprising a continuous matrix of synthetic polymeric material that is impermeable to aqueous alkaline processing composition and that has been obtained from an aqueous dispersion of the polymeric material and, as a discontinuous phase within the matrix, a compatible synthetic polymeric material that is permeable and hydratable by aqueous alkaline processing composition to render the interlayer permeable to dye image-forming material that has been solubilized by the processing composition. The synthetic polymeric material of the discontinuous phase may be a synthetic polymer that is hydratable upon contact with aqueous alkaline processing composition at a rate which renders the intermediate layer permeable to the solubilized dye image-forming material subsequent to development of the silver halide layer possessing the slowest development rate and preceding substantial fogging of the silver halide layer having the fastest fogging rate. The synthetic polymeric material may be hydratable as an inverse function of temperature. The polymeric material forming the continuous matrix is preferably a 60-38-2 terpolymer of methylmethacrylate, butylacrylate and acrylic acid but may also be polyvinylidene chloride, lightly carboxylated styrene-butadiene copolymers, polyvinyl chloride, vinyl chloridevinyl acetate copolymers or acrylic polymers and copolymers. The polymeric material of the discontinuous phase may be isopropyl cellulose, hydroxypropyl cellulose, a copolymer of acrylonitrile and acrylic acid, a copolymer of methyl acrylate and acrylic acid, polyacrylamide, poly-N-ethyl acrylamide, polyethylene oxide, terpolymers of N-ethyl acrylamide, methacrylamide and acrylamide, copolymers of N-ethyl acrylamide and 2-vinyl pyridine, copolymers of N-isopropyl acrylamide and N-vinyl-pyrrolidone, copolymers of N-isopropyl acrylamide and dimethylaminoethyl acrylate or a graft copolymer e.g. a polyvinyl amide graft copolymer. The interlayer may contain a material e.g. succindialdenhyde to prevent exudation of the polymeric discontinuous phase from the layer. The product may comprise an image-receiving element comprising a support and a dyeable polymeric layer either superposed or capable of being superposed on the photo-sensitive element with the two supports outermost. The support of the image-receiving element may be transparent and a reflecting layer comprising an opacifying agent may be present between the dyeable polymeric layer and the nearest silver halide layer or means for forming such a layer may be present in the product. The product may contain a rupturable container containing an aqueous alkaline processing composition and a polymeric acid layer which layer is normally, between the dyeable polymeric layer and the image-receiving element support. Specification 1, 125, 922 is referred to.