Filter dyes photography

Field desorption mass spectrometry radiopharmacological agents, 6,976 Filter dyes photography, 6, 104 Fissile material criticality... 

Acid Yellow 23 (Tartrazine) contains the pyrazolone nucleus. It is prepared by coupling diazotized sulfanilic acid with 5-oxo-l-(4-sulfophenyl)-2-pyrazoline-3-carboxylic acid or by heating oxidized tartaric acid (1 mole) with phenylhydrazinesulfonic acid (2 moles). Acid Yellow 23 is useful as a dye for basic fibers, paper, and leather. It also is used as a filter dye in photography. The purified dye is used in food coloring as FD C Yellow 5. 

A review on image stability in colour photography has been published (79MI11401). Ultraviolet filters which absorb harmful radiation have been used for the protection of image dyes. These are exemplified by the benzotriazole (98) (72GEP2036719) and the pyrrolidine (99) (81BRP1592742). 

Heat-bleachable composition useful in photography. Levinson, Steven Roy Adin, Anthony (Eastman Kodak Co.) Brit. UK Pat. Appl. 2,004,380 (Cl. G03C1/76), 28 Mar 1979, US Appl. 834,587, 19 Sep 1977 15 pp. Heat-bleachable antihalation or filter layers for photog. films are manufd. from an oxidative aryli-midazolyl dimer, e.g. I dimer (R and R = H or Q.4 alkyl), and a formazan dye in a polymeric binder. Thus, 35 mg, 2,4,5-triphenylimidazole dimer was dissolved in 1 g... 

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