Hydrogenated star-shaped polymer
AssigneeShell Oil Company
InventorRudolf J. A. Eckert
Life of this patent
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Abstract
A viscosity index-improver for lubricating oil compositions is disclosed. This viscosity index improver is a hydrogenated star-shaped polymer comprising a poly(poly-alkenyl coupling agent) nucleus and at least four polymeric arms linked to the nucleus wherein the arms are hydrogenated homopolymers and copolymers of conjugated dienes, hydrogenated copolymers of conjugated dienes and monoalkenyl arenes, or mixtures thereof.
Claims38
A lubricating oil composition comprising a major proportion of a lubricating oil and between 0.15 and 10.0% by weight of a hydrogenated star-shaped polymer wherein said polymer comprises a poly(poly-alkenyl coupling agent) nucleus and at least seven polymeric arms linked to said nucleus wherein said polymeric arms are hydrogenated copolymers of conjugated dienes and monoalkenyl arenes.
An oil concentrate comprising a major proportion of a lubricating oil and between about 10% and 30% by weight of a viscosity index improver comprising a hydrogenated star-shaped polymer having a poly(divinylbenzene) nucleus and at least seven polymeric arms linked to said nucleus wherein said polymeric arms are hydrogenated copolymers of monoalkenyl arenes and conjugated dienes.
Dependencies are inferred from the claim text.