GB684541A - Process of inhibiting the degradation of color photographs - Google Patents

Abstract

684,541. Colour photography. GENERAL ANILINE & FILM CORPORATION. April 16, 1951, No. 8823/51. Class 98 (ii). Colour degradation and staining on storage of multi-colour photographic images are inhibited by rinsing, after the final washing operation, in an aqueous solution of an addition product of formaldehyde and a urea of formula wherein R, R 1 and R 2 each represent hydrogen or lower alkyl, and wherein R 2 is always hydrogen when both R 1 and R 2 are lower alkyl. The materials so treated may be multilayer negative, positive or reversible film or white printing material as on a paper base and may contain azo, azine, azomethine, indophenol or quinon- imine dyes produced as from colour formers in the emulsions or in developing solutions. Formaldehyde may be reacted with urea, N-methylurea, N-ethylurea, N-propylurea, N-butylurea, N,N-dimethylurea or N,N<SP>1</SP>-dimethylurea; and reaction products N-methylolurea, N,N<SP>1</SP>-dimethylolurea, N - methylolmethylenebismonoethylurea, N<SP>1</SP> - methylol - N,N - dimethylurea, N - methylol - N,N<SP>1</SP> - dimethylurea or N,N<SP>1</SP> - dimethyluron may be used as in 0.5 to 20 per cent solution for 1 to 10 minutes for rinsing these materials. Four examples are directed to the process as applied to multilayer positives on white opaque film and paper bases and give comparisons after heat, humidity and storage tests with similar but untreated specimens.