Use of manganese oxalates as bleach catalysts
The invention relates to the use of manganese oxalates in detergents and cleaning agents, in particular in cleaning agents containing peroxy compounds for hard surfaces.
1. A process for enhancing the bleaching action of an inorganic peroxygen compound in the bleaching of colored stains comprising the step of adding a bleach catalyst, wherein the bleach catalyst is a manganese(II) oxalate dihydrate or a manganese(II) oxalate trihydrate, to a washing and/or cleaning composition comprising the inorganic peroxygen compound wherein the inorganic peroxygen compound is hydrogen peroxide, alkali metal perborate mono- or tetrahydrate and/or alkali metal percarbonate, and wherein bleaching components of the washing and/or cleaning composition consist of: said inorganic peroxygen compounds; from 0.025 to 2.5% by weight of manganese (II) oxylate dihydrate or a manganese (II) oxylate trihydrate; and optionally (i) a bleach stabilizer selected from phosphonates, borates, metaborates, metasilicates and magnesium salts and/or (ii) a bleaching activator which releases an optionally substituted perbenzoic acid and/or peroxocarboxylic acid under perhydrolysis conditions.
2. A process as claimed in claim 1 , wherein the alkali metal is sodium.
3. A process as claimed in claim 1 , further comprising the step of adding free oxalic acid to the washing and/or cleaning composition.
4. A process as claimed in claim 1 , wherein said bleach activator is tetraacetylethylenediamine.
5. A process as claimed in claim 1 , wherein the manganese oxalate is present in an amount between 0.05 to 1.5% by weight.
6. A process as claimed in claim 1 , wherein the washing and cleaning composition is a cleaning composition for hard surfaces.
7. A process as claimed in claim 1 , wherein the washing and cleaning composition is a dishwashing detergent.
8. A process as claimed in claim 1 , wherein the amount of peroxygen composition is selected such that between 50 ppm and 5,000 ppm of active oxygen is present in the washing or cleaning composition.