Shell Oil Comapny

Robert J Sutherland

Donn A DuBois

Carl Lesley Willis

Dale Lee Handlin, Jr

James R Erickson

Steven H Dillman

Robert B Rhodes

Dean A DuBois

A lubricating oil composition comprising: (a) from 0.01 to 10 percent by weight of a dispersant viscosity index improver linear diblock copolymer or a radial or star copolymer with each arm having an overall number average molecular weight of 7500 to 250,000 and comprising a block of a conjugated diene having a number average molecular weight of 5000 to 200,000 and a block of a vinyl aromatic hydrocarbon having a number average molecular weight of 2500 to 100,000, and a vinyl aromatic hydrocarbon content of 5 to 50 weight percent, wherein from 5 to 10 N-vinyl imidazole functional groups per molecule have been grafted onto the copolymer; (b) from 5 to 20 percent by weight of a dispersant inhibitor package containing 40 percent by weight less ashless dispersant than is required for use with a non-dispersant viscosity index improver; and (c) from 80 to 95 percent by weight of a base oil.

Dispersant viscosity index improvers

Block polymers of the star type contain a central core of crosslinked bisunsaturated compound and a plurality of functionalized branches attached to the core, each branch containing at least a terminal portion of polymerized alkyl methacrylate, polymerized through the ethylenic unsaturation of the methacrylate moiety. The polymers are useful in adhesive formulations and as viscosity index improvers for hydrocarbon fluids.

Functionalized star polymers

An oil composition containing a hydrogenated radial polymer having three rubbery diene arms and one block copolymer arm having a terminal resinous block is provided. It has been found that these asymmetric radial components impart a disproportionately good high temperature/high shear rate viscosity, thus enhancing oil performance under the severe conditions encountered in many modern internal combustion engines.

Oil with asymmetric radial polymer having block copolymer arm

Star polymers having first polymeric arms comprising a hydrogenated conjugated diene and smaller second polymeric arms of a methacrylate resist coupling of methacrylate blocks attached to different cores and have improved performance as viscosity index improvers. The polymerized methacrylate units are converted to amide or imide groups by reaction with a primary or secondary amine to give the viscosity index improver dispersant properties.

Star polymers of dienes, vinylarenes and alkyl methacrylates as modified

Star polymers having polymeric arms of a hydrogenated conjugated diene and substantially smaller polymeric arms of an alkyl methacrylate are efficiently reacted with amines after preparation of a concentrate of the polymer in a lubricating oil to form a dispersant viscosity index improver.

Process for making dispersant viscosity index improvers

An epoxidized diene star polymer having greater than 4 arms and comprising from 0.05 to 5 Meq of di-, tri- and tetra-substituted olefinic epoxides and the molecular weights of the arms are from 1,500 to 15,000.

Randomly epoxidized small star polymers

The present invention provides grafted polymers that have pendent functional groups on the core of the polymer wherein the core is a polymerized alkylmethacrylate having a number average molecular weight from 500 to 1,000,000. The arms of the grafted polymer comprise anionically polymerized segments that have number average molecular weights from 1,000 to 300,000.

Grafted polymers having reactive groups at the base

An engine oil formulation comprising of a pour point depressant, a dispersant inhibitor package containing a reduced amount of ashless dispersant, a synthetic or mineral based oil or mixtures thereof, and a modified hydrogenated star polymer of a conjugated diolefin and a modified hydrogenated copolymer of conjugated diolefins and monoalkenyl arenes is disclosed. The engine oil has and exhibits improved dispersancy and rheological properties which is attributable to the presence therein of the modified hydrogenated star polymer of a conjugated diolefin and a modified hydrogenated copolymer of conjugated diolefins and monoalkenyl arenes. A process of producing the inventive engine oil composition is also disclosed.

Star polymers of dienes, vinylarenes and alkyl methacrylates as modiied

Polymers comprising anionically polymerized conjugated dienes or vinylarenes and adjacent units of (1-methyl-1-alkyl)alkyl esters such as t-butylmethacrylate or (1-aryl-1-alkyl)alkyl esters, as well as selectively hydrogenated derivatives thereof, are heated to at least 170.degree. C. in the presence of an amine to convert the polymerized ester to amide and imide groups.

Low temperature conversion of polymerized esters

Polymers comprising blocks of a hydrogenated conjugated diene (B), a vinylarene (A), and an alkyl methacrylate (M), are readily prepared as a mixture of molecules having the structures B-A-M and B-A-M-A-B wherein both structures are effective as viscosity index improvers for oil compositions. Reaction of the polymers with a primary or secondary amine results in a dispersant viscosity index improver.

Growing community of inventors

Houston, TX, United States of America

Robert J Sutherland