Additive system and method for extending the service life of petroleum based hydraulic fluids
US5700765A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 3, 1995 |
| Grant date | Dec 23, 1997 |
| Priority date | — |
| Expiry date | Aug 3, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10N2070/02
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An additive system and method of use that significantly extend the service life of petroleum based hydraulic fluids, improve antiwear properties, improve demulsibility, condition and swell seals to prevent leaking, increase oxidation life, improve thermal stability, improve corrosion resistance, improve antifoam characteristics, reduce the acid number of used hydraulic oils, and exhibit improved shelf stability and improved low temperature performance when compared to additive systems previously known, the additive system containing as essential elements a stabilized zinc dialkyldithiophosphate, a substituted sulfolane, an alkyl phenol and an effective amount of a solvent alcohol component selected from C.sub.9 -C.sub.11 or C.sub.12 -C.sub.13 alcohols, or other suitable alcohol blends, with or without other suitable adjunctive solvents such as aromatics or aromatic/ketone blends. Where the solvent alcohol component does not include an aromatic, the amount of alcohol preferably ranges from about 5 to about 20 percent by weight of the additive. Where the alcohol component is used in combination with about 5 percent by weight of the additive of an aromatic or with an aromatic/ketone b…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.