Grafted viscosity index improver
US5167848A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1989 |
| Grant date | Dec 1, 1992 |
| Priority date | — |
| Expiry date | May 30, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10N2070/02
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Oil soluble grafted ethylene-alpha-olefin copolymer useful as a viscosity modifier for oleaginous compositions comprising: PA1 (i) backbone copolymer of ethylene and at least one other alpha-olefin monomer, said copolymer comprising intramolecularly heterogeneous copolymer chains containing at least one crystallizable segment of methylene units and at least one low crysallinity ethylene-alpha-olefin copolymer segment, wherein said at least one crystallizable segment comprises at least about 10 weight percent of said copolymer chain and contains at least about 57 weight percent ethylene, wherein said low crystallinity segment contains not greater than about 53 weight percent ethylene, and wherein said copolymer has a molecular weight distribution characterized by at least one of a ratio of M.sub.w /M.sub.n of less than 2 and a ratio of M.sub.w /M.sub.w of less than 1.8, and wherein at least two portions of an individual intramolecularly heterogeneous chain, each portion comprising at least 5 weight percent of said chain, differ in composition from one another by at least 7 weight percent ethylene; having grafted on said backbone copolymer PA1 (ii) residue of ethylenically unsaturate…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.