GB485862A - Improvements in colour photography - Google Patents

Abstract

485,862. Colour photography. I. G. FARBENINDUSTRIE AKT.-GES. Nov. 25, 1936, No. 32273. Convention date, Dec. 7, 1935. [Class 98 (ii)] Separate colour-record images are produced from material having three superimposed layers containing latent colour-record images on a single support, or two superimposed records on one support and a single layer on a second support, the superimposed layers being separated by intermediate layers impermeable to some developers and permeable to other developers or capable of being rendered permeable to other developers by subsequent treatment, by separately developing the several colour-record images and producing the separate colour-records therefrom. For example, if a three layer material is provided with intermediate layers impermeable to alkaline and acid developers respectively, the top layer may bo developed by means of an alkaline developer, copied, and stripped off with its intermediate layer, the second layer then developed with an acid developer, copied and stripped off, and the bottom layer finally developed. Alternatively, the three layers may be separately developed and toned or coloured, copying being effected by coloured lights. In an example, a support carries superimposed blue- and green-sensitive layers separated by a layer impermeable to an acid developer. A red-sensitive layer is provided on a separate support. After exposure, the image in the green-sensitive layer is developed with an acid developer, e.g. a ferrous oxalate developer and copied by light having no blue component onto red- or green-sensitive material. The upper layer is then removed mechanically or chemically and the image in the blue-sensitive layer is developed with an alkaline developer. The image in the red-sensitive layer is developed in the ordinary way. Specification 461,559 is referred to.