Back to results
US 2004/0110647 A1Published application
All-weather tractor hydraulic fluid using a mixture of viscosity modifier types to meet shear-stable multigrade viscosity requirements
AssigneeThe Lubrizol Corporation
InventorRichard E Gapinski
Life of this patent
Estimating the term…
Abstract
A composition of the following components: an oil of lubricating viscosity; a polymethacrylate viscosity modifier; an ester of a maleic acid/styrene copolymer; and optionally, an additive package that imparts to the fluid the capacity to meet bench and dynamometer tests specified by an equipment manufacturer, is suitable for use as a functional fluid such as a tractor hydraulic fluid, under a wide variety of climatic conditions.
Claims10
A composition suitable for use as a functional fluid in a variety of climatic conditions, comprising the following components:
- (a) an oil of lubricating viscosity;
- (b) about 2 to about 30 percent by weight of a viscosity modifier having a weight average molecular weight of about 10,000 to about 60,000;
- and
- (c) about 1 to about 6 percent by weight of a second viscosity modifier having a weight average molecular weight greater than that of component (b) and being about 50,000 to about 200,000;
- wherein one of (b) and (c) is a polyacrylate or polymethacrylate and the other of (b) and (c) is a polymer comprising vinyl aromatic units and esterified carboxyl-containing units.
2 more elements
A concentrate comprising:
- (a) about 10 to about 70 percent by weight of an oil of lubricating viscosity;
- (b) about 20 to about 80 percent by weight of a viscosity modifier having a weight average molecular weight of about 10,000 to about 60,000;
- and
- (c) about 10 to about 60 percent by weight of a second viscosity modifier having a weight average molecular weight greater than that of component (b) and being about 50,000 to about 200,000;
- wherein one of (b) and (c) is a polyacrylate or polymethacrylate and the other of (b) and (c) is a polymer comprising vinyl aromatic units and esterified carboxyl-containing units.
2 more elements
Dependencies are inferred from the claim text.