Compositions and methods for inhibiting corrosion in aqueous media
View Patent ↗Methods and compositions are provided for corrosion inhibition treatment of aqueous systems such as cooling water systems. The methods include conjoint use of a polyvalent metal ion, such as Al or Mn and a corrosion inhibitor/deposit control agent (DCA) to the water system. The corrosion inhibitor DCA agent may be an organic compound such as a hydroxyacid, phosphonocarboxylic acid, polyhydroxysuccinic acid, or polymaleic acid or anhydride.
1. In a water system having a total amount of from about 0.1-1.0 ppm of orthophosphate therein, an improved corrosion inhibition method comprising adding to said system:
a) from about 0.3-0.5 ppm of a polyvalent metal ion selected from Al and Mn; and
b) polymaleic acid or anhydride in an amount of about 1-25 ppm, said polymaleic acid or anhydride being water based.
2. A method as recited in claim 1 further comprising from about 2-25 ppm of c) a polymeric dispersant selected from acrylic acid, acrylic acid copolymers, acrylamides and N-alkylacrylamide polymers and copolymers.
3. A method for inhibiting the corrosion of metals in contact with an aqueous system comprising adding to said aqueous system a) from about 0.1-1.0 ppm of a polyvalent metal ion selected from the group of Al and Mn, and b) from about 1 to less than 50 ppm of a corrosion inhibitor compound selected from the group consisting of saccharic acid, polyepoxysuccinic acid, ammonia hydroxysuccinic acid, p-xylene hydroxysuccinic acid, phosphono-carboxylic acid/phosphonosuccinic acid mixture, phosphonosuccinic oliglomer, and water based polymaleic acid or polymaleic anhydride.
4. A method as recited in claim 3 wherein said saccharic acid is present.
5. A method as recited in claim 3 wherein said phophonosuccinicacid oligomer is present.
6. A method as recited in claim 3 wherein said a mixture of said phosphonosuccinic acid and said phosphono polycarboxylic acid is present.
7. A method as recited in claim 3 wherein said polyethoxysuccinic acid is present.
8. A method as recited in claim 3 wherein said ammonia hydroxysuccinic acid is present.
9. A method as recited in claim 3 wherein said p-xylylene hydroxysuccinic acid is present.
10. A method as recited in claim 3 wherein said water based polymaleic acid or polymaleic anhydride is present.
11. A method as recited in claim 7 further including saccharic acid.
12. A method as recited in claim 7 further including phosphonosuccinic acid oligomer.
13. A method as recited in claim 7 further including a mixture of phosphonosuccinic acid and phosphono polycarboxlic acid.
14. A method as recited in claim 7 further including ammonia hydroxysuccinic acid.
15. A method as recited in claim 7 further including p-xylene hydroxysuccinic acid.
16. A method as recited in claim 7 further including water based polymaleic acid or water based polymaleic anhydride.