Concentrates of a highly branched polymer and functional fluids prepared therefrom
US5484866A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 9, 1993 |
| Grant date | Jan 16, 1996 |
| Priority date | — |
| Expiry date | Nov 9, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10N2070/02
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of a polymer concentrate which is a relatively concentrated solution in a base stock oil, e.g., a mineral oil or synthetic hydrocarbon oil, of a highly branched polymer having segments of a polymer of p-tert-butylstyrene (t-BS), comprising the free radical solution polymerization in the base stock oil of t-BS and optionally, one or more additional polymerizable monoethylenically unsaturated (monofunctional) monomers together with a small amount of a multiethylenically unsaturated (multifunctional) cross-linking agent, e.g., divinylbenzene (DVB). Optionally, the polymer solution obtained from the polymerization may be diluted with an additional amount of the base stock oil employed in the polymerization to obtain a polymer concentrate having a lower polymer concentration and viscosity than the polymerization solution. The polymer concentrate may then be mixed with an additional a amount of base stock oil which may be the same or different from the base stock oil present in the polymer concentrate to obtain a functional fluid, e.g., a lubricating oil, having improved viscometric properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.