GB500945A - Improvements relating to colour photography - Google Patents

Abstract

500,945. Colour photography. GROVES, W. W. (I. G. Farbenindustrie Akt.-Ges.) May 13, 1937, No. 13540. [Class 98 (ii)] In the production of multicolour copies on multilayer photographic material from subtractive multi-colour negatives or positives, the layers of the multilayer copying material are so sensitized that the sensitization maxima coincide or approximately coincide with the absorption maxima of the dyestuffs of the negative or positive which is copied. The copying may be performed with light from which is excluded the spectral region or regions corresponding with the overlapping portions of the absorption zones of the dyestuffs of the negative or positive copied. The filters may comprise dyestuff solutions or coloured gelatine layers, and may comprise several filters for the individual overlapping regions arranged one behind the other. Several dyestuffs may be used in solution or in a layer. A three-layer original has a yellow image produced in the top layer using diethyl-pphenylene diamine as colour developer and pÀundecylaminobenzoylacetanilide -p<1>-carboxylie acid as colour former, a purple image in the middle layer using diethyl-p-phenylenediamine as colour developer and 1-(m-palmitylaminophenyl)-5-pyrazolone-3-carboxylic acid as colour former, and a blue-green image in the bottom layer using diethyl-p-phenylenediamine as colour developer and 2-stearylamino-5- (1-hydroxy-4-sulpho-3-naphthoyl) - aminobenzoic acid as colour former. The copying filter uses a mixture of Crystal Violet and #-naphthoxocarbocyanine. The copying material contains in the middle layer as sensitizer 1:1<1>-diethylbenzthio-# : #<1>-naphthoxy-mesomethylcarbocyanine and in the lower layer the dicyanine dyestuff of formula The colour pictures may be produced in the copying material by colour development, the silver dyestuff bleaching-out process or the anti-diazotate process. Specifications 436,687, 468,400, 466,823, 476,191, 479,838, 483,000, 484,698, 488,853, 489,093, 489,161, 489,164, and 489,274 are referred to.