Metal corrosion inhibition in closed cooling systems
US4728452A · kind A · utility
40Cited by
7References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 17, 1986 |
| Grant date | Mar 1, 1988 |
| Priority date | — |
| Expiry date | Jan 17, 2006 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K5/20
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The corrosion of metals in closed, aqueous cooling systems having a pH of 7.5 to 10.5 is inhibited by adding to the system a coolant concentrate comprising water, at least 10% by weight of a water soluble nitrite or a mixture of a water soluble nitrite and a water soluble nitrate, 0.2 to 2.0% by weight of at least one water soluble azole, and 0.1 to 1.0% by weight of a water soluble molybdate, to provide in the system concentrations of at least 200 ppm of the nitrite or nitrite/nitrate mixture, 2 to 20 ppm of the azole and 1 to 10 ppm of the molybdate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.