Polymeric viscosity index additive and oil composition comprising the same
US4900875A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 1989 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Jan 23, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10M2205/06
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A star-shaped polymer useful as a polymeric VI improver comprising at least one arm which is a block copolymer containing a cunjugated diolefin block and a monoalkenyl aromatic hydrocarbon block and a plurality of arms which are either a homopolymer of a conjugated diolefin or a copolymer of two or more conjugated diolefin or a copolymer of two or more conjugated diolefins. Oil compositions comprising star-shaped VI improvers of this type exhibit relativelylow HTHSR viscosities, and hence, improved fuel efficients when used in automotive applications. Oil compositions comprising star-shaped VI improvers of this type also exhibit improved low temperature pumpability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.