Star shaped asymmetric block copolymer of monoalkenyl aromatic hydrocarbon and conjugated diene
US4849481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1987 |
| Grant date | Jul 18, 1989 |
| Priority date | — |
| Expiry date | Jul 10, 2007 |
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 conjugated 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 tow or more conjugated diolefin or a copolymer of two or more conjugated diolefins. Oil compositions comprising star-shaped VI improvers of this type exhibit relatively low HTHSR viscosities, and hence, improved fuel efficiencies 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.