Bleach-fixing concentrate

Abstract

A one-part photographic bleach-fixing concentrate containing an iron(III) complex salt, a thiosulphate and a sulphite, a disulphite or a sulphinic acid, remains stable if a phosphate, polyphosphate or polyphosphonate, or a nitrate or bromide is added thereto.

1 . A one-part photographic bleach-fixing concentrate containing an iron(III) complex salt, a thiosulphate and a sulphite, a disulphite or a sulphinic acid, characterised in that it additionally contains at least one compound from the series comprising a phosphate, polyphosphate or polyphosphonate, or a nitrate or bromide.  
     
     
         2 . A one-part bleach-fixing concentrate according to  claim 1 , characterised in that its content of thiosulphate is 0.5 to 5 mol/liter, its content of sulphite is 0.2 to 4 mol/liter and its content of Fe(III) complex salt is 0.1 to 1 mol/liter.  
     
     
         3 . A one-part bleach-fixing concentrate according to  claim 1  or  2 , characterised in that its pH is 4 to 9.  
     
     
         4 . A one-part bleach-fixing concentrate according to  claim 1  or  2 , characterised in that its pH is 4 to 6.5.  
     
     
         5 . A one-part bleach-fixing concentrate according to any of  claims 1  to  4 , characterised in that the amount of phosphate, polyphosphate, polyphosphonate, nitrate or bromide is 0.01 to 2.5 mol/liter.  
     
     
         6 . A one-part bleach-fixing concentrate according to any of  claims 1  to  5 , characterised in that it additionally contains one or more complexing agents.  
     
     
         7 . A one part bleach-fixing concentrate according to  claim 6 , characterised in that the additional complexing agent is a polycarboxylic acid or a (poly)hydroxy polycarboxylic acid.  
     
     
         8 . A one part bleach-fixing concentrate according to  claim 6 , characterised in that the additional complexing agent is citric acid.  
     
     
         9 . A one-part photographic bleach-fixing concentrate containing an iron(III) complex salt, a thiosulphate, and a sulphite, a disulphite or a sulphinic acid, characterised in that it additionally contains a phosphate, polyphosphate or polyphosphonate.  
     
     
         10 . A ready-to-use bleach-fixing bath containing an iron(III) complex salt, a thiosulphate, and a sulphite, a disulphite or a sulphinic acid, characterised in that it additionally contains a phosphate and a polycarboxylic acid or a (poly)hydroxycarboxylic acid.  
     
     
         11 . A ready-to-use bleach-fixing bath according to  claim 10 , characterised in that the phosphate is contained in an amount from 0.01 to 0.6 mol and the polycarboxylic acid or (poly)hydroxycarboxylic acid is contained in an amount from 0.5 to 50 mmol per liter.  
     
     
         12 . A ready-to-use bleach-fixing bath according to claims  10  and  11 , characterised in that it is produced from a concentrate according to any of  claims 1  to  9 .