Lost Azochrome

pearl harbored: USP 2,322,084

Azochrome was an early dye destruction(Ciba type) process. Kodak patented the bleaches but never released the product. WWII came to the world as this was being finalized. Patented, but never produced. The patent remains a rich source of information about ‘BLIX’ and dyes that could serve as the foundation to homebrew, low technology “chrome” prints.

The inventors: Richard Young and Merrill Seymour worked at Kodak.

This invention relates to improvements in color photography and mor particularly in processes wherein dyes present in a silver halide emulsion are bleached in the vicinity of a ilver’image.

It is known that the bleaching of dyes selectively in the neighborhood of a silver image can be accomplished by reagents such as acid thiourea. It is possible’to control the contrast of the dye images by the addition of azo dyes or other mild oxidizing agents to the bleaching solutions which cause less image-forming dye to be reduced by a given amount of silver for the available reducing agent because they compete with the azo dyes present in the emulsion, as described in our application Serial No. 355,098 filed August 31, 1940.

It is cited by the Ilford patent US4304846A of Marthaler, and Jan

Processing of exposed silver dye-bleach materials is in general effect in four consecutive steps:

1. Silver developing

2. Dye bleaching

3. Silver bleaching

4. Fixing.

for the class of these type patents see: G03C5/44 Bleaching; Bleach-fixing

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