Viscosity index improvers for lubricating oil compositions
US9133413B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2011 |
| Grant date | Sep 15, 2015 |
| Priority date | — |
| Expiry date | Aug 15, 2032 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10N2070/02
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Polymers suitable for use as a viscosity index improver for lubricating oil compositions including linear polymers characterized by the formula:D′-PA-D″;and star polymers characterized by the formula:(D′-PA-D″)n-X;wherein D′ represents an “outer” block derived from diene having a number average molecular weight of from about 10,000 to about 120,000 daltons; PA represents a block derived from monoalkenyl arene having a number average molecular weight of from about 10,000 to about 50,000 daltons; D″ represents an inner random derived from diene having a number average molecular weight of from about 5,000 to about 60,000 daltons; n represents the average number of arms per star polymer formed by the reaction of 2 or more moles of a polyalkenyl coupling agent per mole of arms; and X represents a nucleus of a polyalkenyl coupling agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.