Lubricant and functional fluid compositions containing viscosity index improver

Patent metadata

Field	Value
Publication number	US-9528069-B2
Application number	US-201213978604-A
Country	US
Kind code	B2
Filing date	Jan 9, 2012
Priority date	Jan 10, 2011
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

The disclosed invention relates to lubricant or functional fluid compositions containing viscosity index improvers in the form of self-healing polymers. The polymers may comprise one or more cleavable linkages, such as one or more disulfide bonds and/or one or more diene/dienophile linkages, to permit the polymer to reform if cleaved during use.

First claim

The invention claimed is:

1. A method of restoring viscosity or viscosity index to a lubricating composition that has degraded during operation of a mechanical device, comprising including within said lubricating composition a viscosity improving amount of about 0.5 to about 20 weight percent of a self-healing polymer consisting of a poly(meth)acrylate which comprises from about 50 to about 90 weight percent monomer units derived from C 12 to C 18 alkyl (meth)acrylate monomer units and one or more linkages comprising one or more disulfide bonds which permit the polymer to reform if cleaved during use.

2. The method of claim 1 wherein the poly(meth)acrylate comprises from about 50 to about 90 weight percent monomer units derived from C 12 to C 15 alkyl (meth)acrylate monomer units and one or more linkages comprising one or more disulfide bonds which permit the polymer to reform if cleaved during use.

3. The method of claim 1 wherein the poly(meth)acrylate further comprises a nitrogen-containing monomer.

4. The method of claim 1 wherein the self-healing polymer comprises a star polymer with a core and a disulfide bond located at the core.

5. The method of claim 1 wherein the self-healing polymer comprises a backbone containing one or more disulfide bonds.

6. The method of claim 1 wherein the self-healing polymer comprises a branched polymer with a backbone and one or more branches which themselves are branched; and containing one or more disulfide bonds in the backbone, in one or more branches, or at one or more branching points.

7. The method of claim 1 wherein the lubricating composition further comprises an overbased metal-containing detergent.

8. The method of claim 1 wherein the lubricating composition further comprises a dispersant.

9. The method of claim 1 wherein the lubricating composition further comprises an antiwear agent.

10. The method of claim 1 wherein the lubricating composition further comprises an antioxidant.

11. The method of claim 1 wherein the lubricating composition further comprises a friction modifier.

12. The method of claim 1 wherein the lubricating composition further comprises a pour point dispersant.

13. The method of claim 1 wherein the lubricating composition further comprises an anti-foam agent.

14. The method of claim 1 wherein the lubricating composition further comprises one or more of phosphorus acids, phosphorus acid salts, phosphorus acid esters, derivative of one or more thereof, or a mixture of two or more thereof.

15. The method of claim 1 wherein the lubricating composition further comprises one or more metal deactivators, supplemental viscosity modifiers, supplemental detergents, corrosion inhibitors, supplemental dispersant viscosity modifiers, extreme pressure agents, demulsifiers, seal swelling agents, or a mixture of two or more thereof.

16. The method of claim 1 wherein the lubricating composition is an engine oil, an automatic transmission fluid, a traction fluid, a continuously variable transmission fluid, a dual clutch automatic transmission fluid, a farm tractor fluid, a manual transmission fluid, a fluid for hybrid vehicle transmissions, or a gear oil.

17. The method of claim 1 wherein the mechanical device comprises an automatic transmission, a continuously variable transmission, a dual clutch automatic transmission, a farm tractor, a manual transmission, a hybrid vehicle transmission, or a gear.

Assignees

• Price David
• Barton William R S
• Lubrizol Corp

Inventors

• Price David
• Barton William R S

Classifications

• C10N2030/02

  Pour-point; Viscosity index · CPC title

• C10N2020/04

  Molecular weight; Molecular weight distribution · CPC title

• C10N2040/046

  for traction drives · CPC title

• C10M161/00

  Lubricating compositions characterised by the additive being a mixture of a macromolecular compound and a non-macromolecular compound, each of these compounds being essential · CPC title

• C10M151/02 Primary

  Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds · CPC title