Claims
- 1. A method of photographic processing comprising bleaching or bleach-fixing an imagewise exposed and color developed color negative photographic silver halide element with a photographic bleaching or bleach-fixing composition that in aqueous form has a pH of at least 4 and comprises:
a) at least 0.01 mol/l of a bleaching agent that comprises ferric ion chelated with 1,3-propylenediaminetetraacetic acid or a salt thereof, and b) at least 0.005 mol/l of an organic polyphosphonic acid, an aminopolysuccinic acid, or a polycarboxylic acid containing at least one hydroxy group as a compound to prevent bleaching agent precipitation.
- 2. The method of claim 1 wherein said bleaching agent precipitation prevention compound is present in an amount of from about 0.01 to about 0.5 mol/l.
- 3. The method of claim 1 wherein said bleaching agent precipitation prevention compound is an amninopolyphosphonic acid or a hydroxy-substituted polyphosphonic acid, or a salt of any of these.
- 4. The method of claim 1 wherein said bleaching agent precipitation prevention compound is 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra(methylenephosphonic acid), morpholinomethanediphosphonic acid, hexamethylenediaminetetra-(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), 2-hydroxy-1,3-propylenediaminetetraacetic acid, hydroxyaspartic acid, citric acid, tartaric acid, malic acid, citramalic acid, hydroxymalonic acid, iminodisuccinic acid, ethylenediaminedisuccinic acid, or dihydroxyfumaric acid, a salt of any of these, or mixtures of any two or more of these.
- 5. The method of claim 1 wherein said bleaching agent precipitation prevention compound is iminodisuccinic acid.
- 6. The method of claim 1 comprising ferric ions in an amount of from about 0.01 to about 1 mol/l.
- 7. The method of claim 1 further comprising a buffer and has a pH of from about 4 to about 8.
- 8. The method of claim 1 further comprising at least 0.0005 mol/l of inorganic phosphate ions.
- 9. A method of photographic processing comprising bleaching an imagewise exposed and color developed color negative photographic silver halide film with photographic bleaching composition that in aqueous form has a pH of from about 5 to about 7 and comprises:
a) from about 0.1 to about 0.4 mol/l of a bleaching agent that comprises ferric ion chelated with 1,3-propylenediaminetetraacetic acid or a salt thereof, and b) from about 0.01 to about 0.5 mol/l of a bleaching agent precipitation prevention agent that is 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra-(methylenephosphonic acid), morpholinomethanediphosphonic acid, hexamethylenediaminetetra-(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), 2-hydroxy-1,3-propylenediaminetetraacetic acid, hydroxyaspartic acid, citric acid, tartaric acid, malic acid, citramalic acid, hydroxymalonic acid, iminodisuccinic acid, ethylenediaminedisuccinic acid, or dihydroxyfumaric acid, a salt of any of these, or mixtures of any two or more of these.
- 10. The method of claim 9 wherein said bleaching agent precipitation prevention agent is iminodisuccinic acid, or a salt thereof.
- 11. The method of claim 1 wherein said bleaching of at least 95 % of the silver is carried out for from about 60 to about 360 seconds at from about 25 to about 50° C.
- 12. The method of claim 1 wherein said imagewise exposed and color developed color negative photographic silver halide element is processed using said photographic bleaching composition after color development and then said element is fixed using a photographic fixing composition.
- 13. The method of claim 1 wherein said bleaching is carried out for from about 30 to about 90 seconds at from about 25 to about 50° C.
RELATED APPLICATIONS
[0001] This is a Continuation-in-part application of U.S. Ser. No. 09/657,022 filed Sep. 7, 2000, by Price and Henry.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09657022 |
Sep 2000 |
US |
Child |
09777112 |
Feb 2001 |
US |