Non-dispersant, shear-stabilizing, and wear-inhibiting viscosity index improver
US5112509A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1988 |
| Grant date | May 12, 1992 |
| Priority date | — |
| Expiry date | Dec 22, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10N2070/02
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method of making a methyl methacrylate-lauryl methacrylate copolymer for use as a non-dispersant, shear stabilizing, wear inhibiting and VI-improving additive in hydraulic fluids and lubricating oils comprises: PA1 (a) first reacting a weight ratio of 10-20 parts methyl methacrylate to 80-90 parts lauryl methacrylate in the presence of 1.0-2.0 weight percent of an alkyl mercaptan at a temperature of 150.degree.-200.degree. F.; PA1 (b) further reacting the reaction product of step (a) in the presence of 0.01-1.0 weight percent of azobis (isobutyronitrile) catalyst at a temperature of 150.degree.-200.degree. F.; and PA1 (c) thereafter heating the reaction product of step (b) at a temperature of 200.degree.-300.degree. F. A concentrate composition comprising a base oil and an effective amount of the methyl methacrylate-lauryl methacrylate copolymer is particularly useful as an additive for use in high-VI hydraulic fluids and lubricating oils.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.