Machine dishwashing compositions containing an oxygen bleach and a bismuth salt to reduce silver tarnishing
AssigneeThe Procter & Gamble Company
InventorsJohn Scott Park, Elizabeth Ann Shaw, Barry Stoddart
Life of this patent
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Abstract
There is provided a composition adapted for use in machine dishwashing having reduced silver-tarnishing, as well as good cleaning performance. The composition contains an oxygen bleach and a water-soluble bismuth compound.
Claims13
A composition, adapted for use in a machine dishwashing method, and having silver anti-tarnishing properties, comprising:
- (a) an oxygen-releasing bleaching system;
- (b) from 0.1% to 5% by weight of the composition of a water soluble bismuth compound;
- and
- (c) said composition being free of a chlorine bleach.
A method for preventing tarnishing of silverware in machine dishwashing using an oxygen bleach-containing detergent composition, comprising the steps of:
- adding from 0.1% to 5% by weight of the compostion of a water-soluble bismuth compound for the pretreatment of silverware to said oxygen bleach-containing detergent composition;
- and
- submitting said silverware to machine dishwashing thereafter.
A method for preventing tarnishing of silverware in machine dishwashing using an oxvgen bleach-containing detergent composition, comprising the steps of:
- delivering from 0.1% to 5% by weight of the composition of bismuth ions to a machine dishwashing solution containing an oxygen bleach by means other than said oxygen bleach-containing detergent composition, said means consisting of a water-soluble bismuth compound.
A method for preventing tarnishing of silverware in machine dishwashing using an oxygen bleach-containing composition, comprising the steps of:
- pretreating said silverware with from 0.1% to 5% by weight of the compostion of a water-soluble bismuth compound prior to submitting said silverware to machine dishwashing using said oxygen bleach-containing composition.
Dependencies are inferred from the claim text.