GB513234A - Bi-pack for colour photography - Google Patents

Abstract

513,234. Colour photography. I. G. FARBENINDUSTRIE AKT.-GES. April 4, 1938, No. 10247. Convention date, April 5, 1937. [Class 98 (ii)] A bipack for colour photography comprises one support bearing two differently sensitized silver halide emulsion layers and another support bearing a single silver halide emulsion layer, the light sensitive layers being in contact and the two sensitive layers carried on the same support contairing a colour former which has been made fast to diffusion in known manner, e.g., as described in Specifications 436,587, 458,400, 465,823, 479,838, 483,000, 484,698, 488,048, 488,853, 489,093, 489,161 and 489,274. In one example, a support carries a blue-sensitive and a green-sensitive layer containing palmitoyl aminobenzoyl acetic acid carboxyphenylamide and the pyrazolone from a - hydrazinostearic acid and ethyl aceto-acetate respectively; a second support carries a red sensitive layer without a colour former. After exposure the two layer film is subjected to reversal and colour development to obtain a colour positive. The single layer is developed and fixed or alternatively developed by reversal and converted by iron blue toning. The two layer film may also be processed by black and white development, fixed, the silver converted to silver chloride and after further exposure, converted into a colour picture by colour development. In a second example the double layer contains a pyrazolone and erucayl-1:8-aminonaphthol-4:6- disulphonic acid as colour formers and is processed by the silver antidiazotate coupling process. The silver bromide may be caused to react with the antidiazotate from paramethoxy - ortho - aminophenylethinylcarbinol, the compounds diazotized and simultaneously coupled to give the dyestuff. In further examples, one support carries the blue-sensitive and red-sensitive layers, and the other support carries the green-sensitive layer, one of the layers in each bipack not containing a colour former. The colour formers specified are (4<1> stearyl - aminobenzoyl - acetanilide - 4 - carboxylic acid, the anisidide of 1:naphthol-2:carboxylic acid and a derivative of pyrazolone.