GB984838A - A process for the production of positives by tanning development under heat - Google Patents

Abstract

984,838. Photographic transfer processes. AGFA A.G. Dec. 5,1962 [Dec. 8, 1961],No. 45976/62. Heading G2C. In a process wherein an exposed gelatine silver halide material containing a tanning developer is developed by heat, and the unhardened parts are transferred during or after development to a receiving sheet to give a positive image (see Specification 821, 506), the receiving sheet contains a thiosemicarbazide or an alkyl, aryl, aralkyl, acyl or substituted aryl derivative thereof. The thiosemicarbazide may be substituted in the 1- position by a phenyl,formyl, methyl or acetyl group or in the H-position by a methyl, ethyl, hexyl, dodecyl, cyclohexyl, 4-methylcyclohexyl, phenyl,p-tolyl,p-methoxyphenyl,benzyl or #- phenylethyl group. Moisture-providing substances may be included in the light-sensitive or transfer layer. These may be substances which split off water on heating such as sodium acetate, or compounds which increase the moisture content of the layer, such as sorbitol, glycerol or polyalkylene glycols. In the examples, the silver halide emulsion contains pyrocatechol, cyclohexanone bisulphite, sodium acetate and benztriazole.