Stabilized bleaching compositions and method of processing color elements
First Claim
Patent Images
1. A photographic bleaching composition comprising:
- a) at least 0.01 mol/l of a bleaching agent that comprises ferric ion chelated with a first chelating ligand comprising an aromatic nitrogen heterocycle, andb) at least 0.01 mol/l of an organic amine base,said bleaching composition being substantially free of inorganic bases and the molar ratio of said organic amine base to said first chelating ligand being at least 1;
1, said organic amine base is ethanolamine, triethanolamine, ethylenediamine, diethylamine, triethylamine, morpholine, tetramethylethylenediamine, piperazine, diethanolamine or 2-methylaminoethanol.
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Abstract
Color photographic elements can be effectively processed to provide color images using biodegradable bleaching compositions in which the bleaching agent includes a pyridinecarboxylic acid or 2,6-pyridinedicarboxylic acid chelating ligand. The bleaching composition is stabilized by incorporation of an organic amine base instead of the conventional inorganic base.
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Citations
21 Claims
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1. A photographic bleaching composition comprising:
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a) at least 0.01 mol/l of a bleaching agent that comprises ferric ion chelated with a first chelating ligand comprising an aromatic nitrogen heterocycle, and b) at least 0.01 mol/l of an organic amine base, said bleaching composition being substantially free of inorganic bases and the molar ratio of said organic amine base to said first chelating ligand being at least 1;
1, said organic amine base is ethanolamine, triethanolamine, ethylenediamine, diethylamine, triethylamine, morpholine, tetramethylethylenediamine, piperazine, diethanolamine or 2-methylaminoethanol. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 20, 21)
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18. A photographic bleaching composition comprising:
- a) at least 0.1 mol/l of a bleaching agent that comprises ferric ion chelated with a first chelating ligand that is unsubstituted 2-pyridinecarboxylic acid or 2,6-pyridinedicarboxylic acid, and a second chelating ligand that is methyliminodiacetic acid or nitrilotriacetic acid, the molar ratio of said first chelating ligand to ferric ion being from about 0.8;
1 to about 2;
1, and the molar ratio of said second chelating ligand to ferric ion being from about 0.5;
1 to about 2;
1, andb) at least 0.1 mol/l of ethanotamine, diethanolamine or triethanolamine, or a mixture of any of these, said bleaching composition being substantially free of inorganic bases and the molar ratio of ethanolamine, diethanolamine or triethanolamine, or a mixture of any of these, to said second chelating ligand being at least 1;
1. - View Dependent Claims (19)
- a) at least 0.1 mol/l of a bleaching agent that comprises ferric ion chelated with a first chelating ligand that is unsubstituted 2-pyridinecarboxylic acid or 2,6-pyridinedicarboxylic acid, and a second chelating ligand that is methyliminodiacetic acid or nitrilotriacetic acid, the molar ratio of said first chelating ligand to ferric ion being from about 0.8;
Specification