GB510598A - Improved material for colour photography - Google Patents

Abstract

510,598. Colour photography. GROVES; W. W. (I. G. Farbenindustrie Akt.-Ges.). Jan. 31, 1938, No. 2985. [Class 98 (ii)] A material for colour photography comprises a support, one or more light sensitive layers and a separate light filter layer for use in projection of the colour picture and which is resistant to decolorizations by photographic treatment baths, the filter layer lying behind the light sensitive layer or layers during the exposure. In one example a layer coloured feebly blue with Brilliant Benzo Fast Green is cast on the emulsion layer of a multi-colour grain screen film or plate, or one coloured with Fulling Yellow and Methyl Blue is cast on the emulsion layer of a lenticular screen film, the latter dye being removed in the treatment baths. The layer which is of a neutral grey colour thus acts as an antihalation layer. A material comprising three superimposed emulsion layers each differently sensitized and on one side of the support, has on the other side of the support a red layer which contains a mixture of Supranol Red B and Supranol Red 3B. The tint of this filter is afterwards determined in accordance with its use, by immersion in a bath of thiourea. The two dyestuffs have a different resistance to the bleaching action of the bath and give a range of colour from blue to red. A material with two emulsion layers on one side and one emulsion layer on the other side of the support has a filter layer of Brilliant Cresyl Blue, the tint being determined by acid or alkaline treatment giving the colours blue or yellow respectively.