Photographic reversal composition and method of use
AssigneeEastman Kodak Company
InventorsJohn S. Badger, Mary E. Craver
Life of this patent
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Abstract
Color reversal photographic films are processed using a reversal solution comprising stannous ion and a quaternary ammonium compound as the sole biocide, to reduce formation of biogrowth. The quaternary ammonium compound is present at very low concentrations of 1 to 20 ppm, and is preferably myristyltrimethyl ammonium bromide because it avoids precipitates with components that leach out of processed films.
Claims11
A precipitate-free photographic reversal composition comprising stannous ion at a concentration of from about 0.002 to about 0.02 mol/l, and myristyltrimethyl ammonium bromide as the sole biocide at a concentration of from about 5to about 20 ppm.
A photographic reversal composition having a pH of from about 4 to about 7 and comprising:
- a) stannous ion at a concentration of from about 0.004 to about 0.01 mol/l,
- b) a quaternary ammonium compound as the sole biocide at a concentration of from about 5 to about 20 ppm, said quaternary ammonium compound being myristyltrimethyl ammonium bromide,
- c) a stannous ion stabilizer, and
- d) an organic phosphonic or phosphinic acid chelating agent.
Dependencies are inferred from the claim text.