Patent GB-522611-A (GB)
Title: Photographic multilayer material
IPC: G03C7/28
Filed: 1938-12-12
Abstract: 522,611. Colour photography, GASPAR, B. Dec. 12, 1938, No. 36170. [Class 98 (ii)] [Also in Group IV] Light-sensitive multilayer material for the preparation of multicolour images by the local reductive destruction of azo-dyes contains in at least one silver halide emulsion layer a catalyst for the dye destruction. The catalyst may preferably be present in that silver halide emulsion layer containing the dye with the lowest bleaching speed. The catalyst may be precipitated as an insoluble compound by a precipitating agent that also precipitates the dye or dye-former present in the layer or may undergo mutual precipitation with the dye or dyeformer. Alternatively the catalyst may be insoluble or may be such that it is washed out from the emulsion binder only with difficulty. The property of insolubility or fastness may be imparted by chemical substitution. The emulsion binder may be gelatin, a cellulose derivative, an artificial resin, or an albuminoid. A silver halide emulsion may contain Supranolbrillantrot B, the acetate of the dibiguanide derived from mm'- dichlorbenzidine, and sulphonated 3 : 3'-carbonylbis-2-hydroxy-3-aminophenazine. The dye destruction solution may be hydrochloric acid solution containing potassium iodide. The emulsion may be employed in the production of multilayer material having several differentially colour sensitized emulsion layers on one or both sides of a support. Intermediate plain colloid layers may be provided. A silver halide emulsion without a catalyst that may be used in such material contains Brillantbenzoechtgr³n GL. The third layer may be coloured or colourless, and in the latter case the dye is incorporated or the dye-former transformed into the dye before dye-destruction. Dye-destruction may be effected in an acid fixing bath. An additional catalyst may be employed in the dye-destruction bath. Catalysts suitable for incorporation in the emulsion are 2-lauroylamino and 2-stearoylamino - 3 - aminophenazine, tetrabromodimethylquinoxaline, tetrabromodimethylquinoxaline sulphonic acid, #-phenylnaphthoquinoxaline, #-phenylnapthoquinoxaline sulphonic acid, pamino-#-phenylnaphthoquinoxaline, the condensation product from 2-hydroxy-3-aminophenazine sulphonic acid and cyanuric chloride, the condensation product from 2:3-diaminophenezine and m-aminobenzaldehyde, naphthophenazine-#- sulphonic or -5-carboxylic or -2-carboxylic acid, dimethylquinoxaline carboxylic acid anilide, and the condensation product of 2:3-diaminophenazinesulphonic acid and formaldehyde. Specifications 397,159, 408,991, 415,040, 421,534, 450,685, and 490,451, are referred to. Tetrabromodimethylquinoxaline is prepared by the condensation of tetrabromodiacetyl and o-phenylenediamine in boiling glacial acetic acid. Tetrabromodimethylquinoxalinesulphonic acid is similarly prepared using 1:2-phenylenedramine-4-sulphonic acid. 3 : 3<SP>1</SP>-Dichloro - 4 .4<SP>1</SP> - diphenyldibiguanide is prepared by condensing mm<SP>1</SP>-dichlorbenzidine and dicyandiamide in the presence of hydrochloric acid, and may be crystallised as the acetate. P-amino-#-phenylnaphthoquinoxaline is prepared by hydrolysing p-acetoaminophenynapththoquinaxaline, which is prepared by condensing p-acetoaminoacetophenone and benzene azo-# naphthylamine by means of hydrochloric acid in boiling xylene. 2:3-Diaminophenazine may be condensed with m-aminobenzaldehyde or 2:3-diaminophenazinesulphonic acid with formaldehyde in the presence of hydrochloric acid. Dimethylquinoxaline carboxylic acid anilide is prepared by condensing 3: 4-diaminobenzoic acid with diacetyl, boiling with excess thionyl chloride and distilling off the excess, and heating with excess aniline. Sulphonated 3: 3<SP>1</SP>-carbonyl-bis-2-hydroxy-3- aminophenezine is prepared by sulphonating 2-hydroxy-3-aminophenazine and reacting the product with phosgene. A condensation product is prepared from 2- hydroxy-3-aminophenazinesulphonic acid and cyanuric chloride in a solution containing sodium hydroxide and carbonate at OC. Naphthophenazine-2-carboxylic acid is prepared by the condensation of 3 :4-diaminobenzoic acid and α-nitroso-#-naphthol. #-Phenylnaphthoquinoxalinesulphonic acid is prepared by sulphonating #-phenylnaphthoquinoxaline.