Cooling water corrosion inhibition method
US4929425A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1988 |
| Grant date | May 29, 1990 |
| Priority date | — |
| Expiry date | Feb 12, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23F11/08
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for inhibiting corrosion in industrial cooling waters which contain hardness and a pH of at least 6.5, by dosing the water with a composition which comprises a water-soluble inorganic phosphate capable of inhibiting corrosion in an aqueous alkaline environment and a hydrocarbon polymer containing an N-substituted acrylamide polymers with an amide structure as follows: ##STR1## where R.sub.2 is hydrogen or methyl, where R.sub.1 is a hydrogen or an alkyl and R is alkylene or phenylene, and X is sulfonate, (poly)hydroxyl, (poly)carboxyl or carbonyl, and combinations thereof; or containing derivatized maleic anhydride homo-, co- and terpolymers having N-substituted maleamic acid units, N-substituted maleimide units and maleic acid (and salts) units having a structure as follows: ##STR2## where R.sub.1, R.sub.2 and R.sub.3 are each independently chosen from the group consisting of hydrogen, hydroxyl, carboxyalkyl, carboxyamide, phenyl, substituted phenyl, linear or branched alkyl of from one to ten carbon atoms, and substituted alkyl or from one to ten carbon atoms, where the substituent is phosphonic acid; phosphinic acid; phosphate ester; sulfonic acid; sulfate ester, carboxy…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.