Method and composition to inhibit staining of porcelain surfaces by manganese
AssigneeThe Procter & Gamble Company
InventorJames L. Kurtz
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Abstract
Method and composition to inhibit the staining of water-contacting surfaces, such as those in a toilet bowl, which is caused by manganese present in household water in the presence of an oxidizing material. Manganese staining is inhibited by supplying to the water 0.1 to 10 ppm of a partially hydrolyzed polyacrylamide material. Compositions are also described in the context of an automatic toilet tank dispenser which provides sufficient quantities of the above material in solution to inhibit manganese staining of toilet bowl surfaces.
Claims7
A method of inhibiting the staining of surfaces in contact with water which contains at least about 50 ppb of manganese II ions and an oxidizing agent which would oxidize said manganese (II) ions to form staining manganese (IV) ions;
- said method comprising the step of independently dispensing into said water which contains said manganese (II) ions and said oxidizing agent, from about 0.1 ppm to about 10 ppm of water-soluble, partially hydrolyzed polyacrylamide material having an average molecular weight of from 2000 to 10,000 atomic mass units, and wherein the polyacrylamide contains amide groups which were hydrolyzed to carboxylate/carboxylic acid moieties.
Dependencies are inferred from the claim text.