GB1378172A - Radiographic silver halide elements - Google Patents

Abstract

1378172 Photographic silver halide material AGFA-GEVAERT 20 Dec 1971 [5 Jan 1971] 30814/74 Divided out of 1378171 Heading G2C A radiographic silver halide element comprises a support bearing at each side thereof a lightsensitive layer containing a colour coupler which upon coupling with an oxidized aromatic primary amino colour developer forms a dye mainly absorbing in the green and red spectral regions; wherein the light-sensitive layers are composed of a mixture of two independently prepared silver halide emulsions one of which is capable of producing a visible image by an exposure and subsequent development as above and the other of which is a silver chloride containing emulsion whose speed is so low that no visible image is produced therein by the said exposure and development. The colour coupler may be a phenol or α-naphthol type. The image forming emulsion may be silver chloride, silver bromide, silver chlorobromide, silver bromoiodide or silver chlorobromoiodide. The low speed emulsion may be silver chloride or silver chlorobromide. Development is carried out at a temperature of at least 30‹C . The low speed emulsion prevents the gradation being reduced by rapid development at elevated temperatures.