Viscosity index improving additives for phosphate ester-containing hydraulic fluids
US5817606A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1997 |
| Grant date | Oct 6, 1998 |
| Priority date | — |
| Expiry date | Jul 24, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10N2040/135
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Polymer compositions derived from selected alkyl (meth)acrylate ester monomers used in certain weight ratios to provide improved viscosity control and low temperature performance characteristics in phosphate ester aircraft hydraulic fluids is disclosed. Polymer compositions for use as viscosity index improving additives in aircraft hydraulic fluids contain from 40 to 100 weight percent (C.sub.1 -C.sub.10)alkyl (meth)acrylate and zero to 60 weight percent (C.sub.11 -C.sub.20)alkyl (meth)acrylate monomer units. Preferred polymer compositions based on 40 to 70 weight percent (C.sub.1 -C.sub.10)alkyl (meth)acrylate and 30 to 60 weight percent (C.sub.11 -C.sub.15)alkyl (meth)acrylate monomer units combine good solubility in the phosphate ester hydraulic fluids with good viscosity control at low and high temperatures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.