Photographic bleach composition
AssigneeEastman Kodak Company
InventorJohn Richard Fyson
Life of this patent
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Abstract
A photographic bleach solution contains hydrogen peroxide, or a compound capable of releasing hydrogen peroxide, and two or more sequestering agents capable of complexing with a transition metal. The bleach solution ha a pH in the alkaline range. A method of using such a photographic bleach solution is also disclosed.
Claims16
A photographic bleach solution, comprising hydrogen peroxide, or a compound capable of releasing hydrogen peroxide, and two or more sequestering agents capable of complexing a transition metal ion, wherein said bleach solution has a pH in the alkaline range, wherein each sequestering agent is selected from the group consisting of a polyalkylcarboxylic, polyalkylphosphonic or polyalkylsulphonic acid of formula (I) ##STR6## wherein X.sup.1 and X.sup.2 may be the same or different and each is a hydrogen atom, a straight or branched chain alkyl group having 1 to 6 carbon atoms, a hydroxyl, carboxyl, sulphonyl or phosphonyl group or the group Z, wherein group Z is ##STR7## wherein a, b, c and d are the same or different and each is a hydrogen atom, a straight or branched chain alkyl group having 1 to 6 carbon atoms, a hydroxyl, carboxyl, sulphonyl or phosphonyl group or one or both of X.sup.1 and X.sup.2 may be repeat units of group A or group B, wherein group A is ##STR8## and group B is ##STR9## Y is the same as a, b, c, and d or is the group Z or the group B, wherein X.sup.3 and X.sup.4 are the same or different and the same as X.sup.1 and X.sup.2,
- wherein the sum of m, n and r is an integer from 1 to 10, and
- wherein one or both of the hydrogen atoms in each of the (CH.sub.2).sub.m, (CH.sub.2).sub.n or (CH.sub.2).sub.r groups may be replaced by a straight or branched chain alkyl group having 1 to 6 carbon atoms, with the proviso that at least one of X.sup.1, X.sup.2, X.sup.3 and X.sup.4 comprises a sulphonyl or phosphonyl group or a salt thereof, or at least three of X.sup.1, X.sup.2, X.sup.3 and X.sup.4 comprise a carboxylic group or a salt thereof;
- a diphosphonic acid of formula (II) ##STR10## wherein X is a hydrogen atom, a halogen atom or a hydroxyl group and n is an integer from 0 to 12;
- a polyhydroxyphenyl compound of formula (III) ##STR11## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are the same or different and each is a hydrogen atom, a straight or branched chain alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a sulphonyl group or a carboxyl group;
- and
- a polyphosphate of formula (IV)
- HO(P(O)(OH)O--).sub.n H (IV)
- wherein n is from 4 to 12
- or an alkali metal salt thereof.
A method of processing a color material, comprising:
- providing an exposed and developed color silver halide photographic material, and
- contacting said developed color photographic material with a bleach solution comprising hydrogen peroxide, or a compound capable of releasing hydrogen peroxide, and two or more sequestering agents capable of forming a complex with a transition metal ion, wherein said bleach solution has a pH in the alkaline range
- wherein each sequestering agent is selected from the group consisting of a polyalkylcarboxylic, polyalkylphosphonic or polyalkylsulphonic acid of formula (I) ##STR12## wherein X.sup.1 and X.sup.2 may be the same or different and each is a hydrogen atom, a straight or branched chain alkyl group having 1 to 6 carbon atoms, a hydroxyl, carboxyl, sulphonyl or phosphonyl group or the group Z, wherein group Z is ##STR13## wherein a, b, c and d are the same or different and each is a hydrogen atom, a straight or branched chain alkyl group having 1 to 6 carbon atoms, a hydroxyl, carboxyl, sulphonyl or phosphonyl group or one or both of X.sup.1 and X.sup.2 may be repeat units of group A or group B, wherein group A is ##STR14## and group B is ##STR15## Y is the same as a, b, c, and d or is the group Z or the group B, wherein X.sup.3 and X.sup.4 are the same or different and are the same as X.sup.1 and X.sup.2
- wherein the sum of m, n and r is an integer from 1 to 10 and
- wherein one or both of the hydrogen atoms in each of the (CH.sub.2).sub.m, (CH.sub.2).sub.n or (CH.sub.2).sub.r groups may be replaced by a straight or branched chain alkyl group having 1 to 6 carbon atoms, with the proviso that at least one of X.sup.1, X.sup.2, X.sup.3 and X.sup.4 comprises a sulphonyl or phosphonyl group or a salt thereof, or at least three of X.sup.1, X.sup.2, X.sup.3 and X.sup.4 comprise a carboxylic group or a salt thereof;
- a diphosphonic acid of formula (II) ##STR16## wherein X is a hydrogen atom, a halogen atom or a hydroxyl group and n is an integer from 0 to 12;
- a polyhydroxyphenyl compound of formula (III) ##STR17## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are the same or different and each is a hydrogen atom, a straight or branched chain alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a sulphonyl group or a carboxy group;
- and
- a polyphosphate of formula (IV)
- HO(P(O)(OH)O--).sub.n H (IV)
- wherein n is from 4 to 12
- or an alkali metal salt thereof.
Dependencies are inferred from the claim text.