GB481699A - Improvements in fog inhibitors for photographic silver salt emulsions - Google Patents

Abstract

481,699. Photographic emulsions. KODAK, Ltd. May 7, 1937, No. 13082. Convention date, May 7, 1936. [Class 98 (ii)] Photographic silver salt emulsions are stabilized by the incorporation therein of a compound whose formula comprises two simple substituted or unsubstituted benzene nuclei each containing an amino group, a carbon atom of each of which is linked together by means of a single bond or by one or more atoms linked by single bonds. The use of benzidine, tetramethylbenzidine, diacetylbenzidine, o-tolidine, dianisidine, p : p<1> : diamin.odiphenylmethane, p : p<1>-tetramethyldiaminodiphenylmethane, p : p<1>-tetramethyldiaminodiphenylmethane, and 2 : 2<1> : 4: 4<1>-tetra-amino- 5 : 5<1>-dimethyldiphenylmethane is referred to. The compounds may be incorporated by mixing with water, methyl alcohol, ethyl alcohol or acetone, and may be added before or after colour-sensitizing dyes. The emulsion may be silver bromide, chloride or iodide or mixtures thereof dispersed in gelatine, collodion, albumen, cellulose organic derivatives or artificial resins.