GB454088A - Improvements relating to colour photography - Google Patents

Abstract

454,088. Colour photography. GROVES, W. W., 30, Southampton Buildings, Chancery Lane, London.-(I. G. Farbenindustrie Akt.- Ges.; Frankfort-on-Main, Germany) Dec. 21, 1934, No. 36693. [Class 98 (ii)] A copying material for colour photography comprises a plurality of silver halide emulsion layers arranged on one or both sides of a support, one or more layers containing the dyestuffs for the finished pictures and the other layers which serve also to produce colour component pictures, , do not contain such dyestuffs or substances capable of conversion into such dyestuffs. In one example, a support is coated on one side with an emulsion coloured blue green with Chicago Blue, and on the other side with an emulsion dyed with Sirius Ruby and sensitized to red, and an uncoloured layer which is not specially colour-sensitized. After copying, the layers are developed, and the uncoloured layer is dyed by a suitable yellow solution, e.g. of Chrysophenine Yellow and the silver parts bleached out as in the process described in Specification 133,034, [Class 98 (ii)], or Specification 401,340. The layers may also be arranged on one side of the support. In another example the support is coated on one face with a red-sensitized emulsion coloured purple, and a yellowcoloured emulsion not specially colour-sensi. tized, and on the other face with an uncoloured green-sensitized emulsion. The two coloured layers are exposed behind intermediate positives while the back face is exposed behind a negative, and they are converted to the appropriate colour images by a bleaching out process and a ferrocyanide bath respectively. The green-sensitized layer may be dyed yellow as by Korallin yellow in order to obtain a gradation adapted to the other sensitive layers. Specification 395,124 also is referred to.