Photographic colour developers and processes of producing reversed colour developed photographic images

摘要

1,020,032. Photographic colour developers. EASTMAN KODAK CO. Sept. 7, 1962 [Sept. 11, 1961], No.34357/62. Heading G2C. Aqueous alkaline photographic silver halide colour developers include a thioether of formula wherein R 1 and R 2 each represent a C 2-10 alkylene group. They may be prepared as described in Specification 950,089 which relates to their use as sensitisers for silver halide emulsions. The aqueous alkaline developer may also contain colour couplers and various conventional ingredients and reference is made to numerous prior specifications to exemplify these and also the emulsions which may be developed. Particular reference is made to the use of such developers in reversal processes wherein an element having plural colour-sensitive silver halide emulsion layers containing colour couplers on a single support which has been exposed and developed to produce black and white negative images and the residual silver halide images in the layers are either selectively exposed and colour developed in succession or are made developable and are simultaneously colour developed.