Patent GB-467380-A (GB)
Title: Photographic material for colour photography or kinematography
IPC: G03C1/83
Filed: 1936-07-29
Abstract: 467,380. Colour photography. TRUECOLOUR FILM, Ltd., and DOLGORUKI, E. SANDERS-. July 29, 1936, No. 20943. Drawings to Specification. [Class 98 (ii)] Multilayer sensitive material for direct exposure in a camera, or for printing, comprises a transparent support as of celluloid, two superimposed emulsion layers on one side, a single emulsion layer or two superimposed emulsion layers on the other side, and decolourable filter layers between some or all of the emulsion layers. For three-colour work, the material may comprise, in order from front to rear a blue-sensitive layer, a gelatine layer containing a yellow filter dye (e.g. Orange 2), a greensensitive layer, a gelatine layer containing a minus-green filter dye (e.g. Phloxine), the support, and a red-sensitive layer. The filter layer adjacent the support may be on either side, or there may be a similar layer on each side, or the dye may be included in the material of the support. The order of the layers may be modified by interchanging the green and red-sensitive layers, and replacing the minus-green filter by a minus-red filter (e.g. Patent Blue 5). The same material may be adapted for four-colour work, or for three-colour work with a grey-key fourth image, by coating a second emulsion layer on the rear side, and if necessary interposing a filter layer between the two emulsion layers. In another form for four-colour &c. work, the order of the layers is, from front to rear, panchromatic or infra-red sensitive emulsion, blue sensitive emulsion, yellow filter, support, redsensitive emulsion, minus-red filter, and green sensitive emulsion ; and as before the disposition of the yellow filter may be altered, and the red and green sensitive emulsions may be interchanged. In any of the forms, the second filter may be dispensed with if the yellow filter alone provides sufficient correction. The filter dyes may be incorporated in the substratum layers. After exposure, the layers may be processed to colours in known manner, as by dye-toning or colour development, or by the selective destruction of dyestuffs present in or formed in the emulsion layers, and the filter dyestuffs are eliminated at any desired stage, e.g. in the developing bath. To facilitate differential processing of the layers, the material may be provided on the back with an outer layer of waterproof varnish which may be removed or rendered permeable after the layers on the front have been processed in order to permit processing of the rear layers ; and this varnish layer may contain dye or lamp black so that it may serve as an anti-halation layer. When used as printing material, copies may be made upon it from masters made on multilayer material of the same kind, or on lenticular or multicolourscreen material, or from separate components taken on packs. Reference is made to the multilayer sensitive material described in Specification 444,198. Reference has been directed by the Comptroller to British Specifications 415,040, 427,472, 440,089, 440,422, 441,325, 446,234, and U.S.A. Specifications 1,954,346 and 2,010,459.