Asymmetrical radial polymer and composition of matter comprising the same
US5302667A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1993 |
| Grant date | Apr 12, 1994 |
| Priority date | — |
| Expiry date | Oct 1, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10M2205/20
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An improved VI improver and a fluid composition comprising the VI improver. The VI improver is an asymmetric radial polymer comprising a plurality of arms having at least two distinctly different peak molecular weights, which arms are chemically the same. The weight ratio of a longest set of arms and a first set of shorter arms will vary within the range from about 1.2:1 to about 8.0:1. If more than one set of shorter arms is used the ratio of adjacent arms molecular weights will vary within the same range. While the arm might be essentially any polymer, polymers of conjugated diolefins and copolymers of at least one monoalkenyl aromatic hydrocarbon and at least one conjugated diolefin are preferred. Conjugated diolefin homopolymers are preferred and polyisoprene is most preferred.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.