GB431072A - Improvements in colour photography - Google Patents

Abstract

431,072. Colour photography. I. G. FARBENINDUSTRIE AKT.-GES., Frankfort-on-Main, Germany. Jan. 1, 1934, No. 79. Convention date, Dec. 30, 1932. Addition to 345,575. [Class 98 (ii)] Two-colour, or multicolour photographic pictures are produced by printing two component negatives, either simultaneously or consecutively, from opposite sides of a photographic material having two layers sensitized with colourless esters or ester salts of leucodyestuffs, the layers being superimposed on one face of a support or carried one on each face of a transparent support. In a modification, the layers are self-supporting and are united by adhesive or an intermediate adhesive layer. An absorbent of ultraviolet light, e.g. aesculin, may be incorporated in the support, or between the layers. Supports of gelatin, casein, cellulose or cellulose derivatives and glass are specified. Thus, sensitized gelatin layers may be applied to the same side or to opposite sides of a support of cellulose nitrate or acetate, or sensitized sheets of cellulose hydrate may be applied to one or both faces of a thin glass plate ; or a cellulose acetate sheet may be superficially saponified and impregnated with solutions of a suitable ester or ester salt of a leuco-dyestuff. After printing two component negatives from opposite sides and fixing the component pictures, one or both sides may be further sensitized, by impregnation or coating, to produce a third and fourth colour. Anaglyphs may be produced by the two-colour method. Examples of two- and three-colour processes and materials are given. The Specification as open to inspection under Sect. 91, refers also to the use of coloured esters or ester salts of leuco compounds. This subject-matter does not appear in the Specification as accepted.