Extended engine coolant lifetime through polymeric polycarboxylate secondary silicate stabilization
US6203719A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 1997 |
| Grant date | Mar 20, 2001 |
| Priority date | — |
| Expiry date | Jan 10, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K5/20
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention provides corrosion inhibition formulations and compositions for inhibiting mineral scale and the corrosion of metals particularly the cavitation corrosion of aluminum in the presence of aqueous liquids. The combination of a mixture of polymeric polycarboxylates, azoles, nitrate salts, phosphates, stabilized silicates and transition metal compounds provide a synergistic protective effect against the cavitation corrosion of aluminum in aqueous liquids reducing the corrosion rate and is effective at relatively low concentrations and varying pH ranges. The addition of selected polymeric polycarboxylates not only significantly reduces glycol based coolant cavitation erosion-corrosion, heat rejecting aluminum corrosion, and hard water precipitates and scale, it has been discovered that polymeric polycarboxylates in combination with siloxane stabilized silicates enhance secondary silicate stabilization leading to improvement in aluminum corrosion protection and coolant life when utilized with selected amounts of the above-identified additives. The formulations are particularly suitable for automotive applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.