GB803783A - Photographic materials - Google Patents

Abstract

803,783. Photographic materials and processes. IMPERIAL CHEMICAL INDUSTRIES, Ltd. Oct. 19, 1956 [Nov. 1, 1955], No. 31179/55. Class 98(2) A photographic gelatino - silver halide emulsion containing a compound of the general formula : wherein R 1 and R 2 are substituted or unsubstituted alkyl groups or are joined together or each or both are joined to the benzene ring to form a heterocyclic ring, X is hydrogen, alkyl, substituted alkyl, alkoxy, substituted alkoxy, amino or substituted amino, and Y is a solubilizing group such as carboxy or sulpho, is developed in an alkaline solution of hydroxylamine or hydrazine. The emulsions may contain sensitizing dyes and colour couplers. The phthalimide derivative may be one wherein R 1 and R 2 are ethyl, X is H, NH 2 , C 2 H 5 O or CH 3 and the phthalimide ring contains a -COOH or -SO 3 H group. In an example, a paper coated with a gelatine silver iodo-bromide emulsion containing 3 : 3<SP>1</SP>-diethyl-5:5<SP>1</SP>-diphenyl-9-ethyloxacarbocyanine iodide and sodium. 4- (omega - cyanacetyl) - octadecenyl - succinanilide coupler and to which (has been added an aqueous gelatin dispersion containing 4(4<SP>1</SP>-carboxy-phthalimido)-3-ethoxy. N : N-diethylaniline and sodium dioctylsulphosuocinate, is exposed and developed in aqueous hydroxylamino solution containing sodium carbonate. The paper is then immersed in a hypo/acetic acid stop bath and the silver bleached in a hypo bath containing sodium carbonate, sulphite, bromide and the sodium and ferric salts of ethylenediamine tetra-acetic acid. Specification 775,692 is referred to.