High molecular weight polyacrylates for aluminum protection in warewash applications
AssigneeEcolab USA Inc.
InventorsErik C. Olson, Devon Beau Hammel
Life of this patent
Estimating the term…
Abstract
A warewashing detergent composition is provided for use for in cleaning of alkaline sensitive metals such as aluminum or aluminum containing alloys. The compositions include alternatives to sodium tripolyphosphate and/or other phosphorous containing raw materials, while retaining cleaning performance and corrosion prevention. According to the invention, high molecular weight polyacrylates (polyacrylic acid homopolymers) with a molecular weight of at least about 5000 are used as corrosion inhibitors and can be included for aluminum protection in a number of different detergent compositions.
Claims14
A detergent composition comprising:
- (a) an alkaline source in an amount effective to provide a use composition having a pH of at least about 8 and obtained by diluting the detergent composition with water;
- and
- (b) from about 10 wt. % to about 50 wt. % of a corrosion inhibitor component capable of reducing corrosion of aluminum or aluminum containing alloys, the corrosion inhibitor component comprising one or more polyacrylic acid homopolymers having a molecular weight of at least about 10,000 daltons;
- (c) from about 0.5 wt. % to about 20 wt. % of a surfactant;
- wherein the composition comprises less than 0.1 wt. % phosphorous, sodium tripolyphosphate, or 1-hydroxy ethylidene 1-1-diphosphonic acid;
- and
- wherein the composition does not include sodium carbonate, and wherein the composition is substantially free of calcium salts.
A method for protecting aluminum or aluminum-containing alloys from corrosion comprising:
- (a) providing aluminum or aluminum-containing alloys;
- and
- (b) contacting a surface of the alloys with a use solution of a composition, wherein the composition comprises from about 10 wt. % to about 50 wt. % of a corrosion inhibitor, from about 0.5 wt. % to about 20 wt. % of a surfactant, and an alkaline source in an amount effective to provide a use composition having a pH of at least about 8;
- wherein the corrosion inhibitor comprises one or more polyacrylic acid homopolymers having a molecular weight of at least about 10,000 daltons, and having less than 0.1 wt. % phosphorous, sodium tripolyphosphate, and 1-hydroxy ethylidene 1-1-diphosphonic acid, and
- wherein the composition does not include sodium carbonate and wherein the composition is substantially free of calcium salts.
Dependencies are inferred from the claim text.