Lubricant composition containing copolymers of polyisobutylenemethacrylate

Patent metadata

Field	Value
Publication number	US-11214752-B2
Application number	US-201816622474-A
Country	US
Kind code	B2
Filing date	Jul 19, 2018
Priority date	Jul 28, 2017
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

The present invention is directed to the use of poly(polyisobutylenemethacrylate) as viscosity index improving component in lubricating oil compositions. The invention is further related to lubricating oil compositions comprising poly(polyisobutylenemethacrylate) with enhanced shear stability.

First claim

The invention claimed is:

1. A lubricating oil composition comprising:
(a) a base oil,
(b) a poly(polyisobutylenemethacrylate) copolymer (polyPIBMA) comprising polyisobutylene macromonomers (PIBMA) of formula (I)

wherein
R 1 to R 5 independently from each other are selected from the group consisting of hydrogen, C 1 -C 20 -alkyl, C 1 -C 20 -alkyloxy and C 8 -C 7500 -polyisobutyl C 8 -C 7500 -polyisobutenyl,
R is an alkylene group comprising 2 to 10 carbon atoms,

R 6 is hydrogen or methyl,
R 7 is hydrogen or methyl, or COOR 8 ,
R 8 is hydrogen or C 1 -C 20 -alkyl and
n is a number from 1 to 50,
characterized in that at least one of R 1 to R 5 is a C 8 -C 7500 -polyisobutyl or C 8 -C 7500 -polyisobutenyl,
and
(c) additives.

2. The lubricating oil composition of claim 1 , comprising
a) 70 to 99.9 weight percent base oil,
b) 0.1 to 50 weight percent of a poly(polyisobutylenemethacrylate) copolymer,
c) 0.05 to 20 weight percent of additives.

3. The lubricating oil composition according to claim 1 , comprising polyPIBMA, which has a number average of carbon atoms on the side chains of at least 6.

4. The lubricating oil composition according to claim 1 , comprising at least one additive selected from the group consisting of antioxidants, oxidation inhibitors, corrosion inhibitors, friction modifiers, metal passivators, rust inhibitors, anti-foamants, viscosity index enhancers, additional pour-point depressants, dispersants, detergents, further extreme-pressure agents and/or anti-wear agents.

5. The lubricating oil composition according to claim 1 , having a viscosity loss as measured according to ASTM D6278 of less than 15%.

6. The lubricating oil composition according to claim 1 , having a cold crankcase viscosity measured according to ASTM D2293 at −35° C. of less than 6500 mPas.

7. The lubricating oil composition according to claim 1 , having a viscosity index of at least 180.

8. The lubricating oil composition according to claim 1 , where the poly(polyisobutylenemethacrylate) copolymer comprises 5-50% PIBMA according to formula (I) by weight, 0-50% of methyl(meth)acrylate and 0-80% (meth)acrylate with C 2 -C 22 alkyl chains.

9. The lubricating oil composition according to claim 1 , where the poly(polyisobutylenemethacrylate) copolymer comprises 10-35% PIBMA according to formula (I) by weight, 20-40% methyl (meth)acrylate, and 25-70% (meth)acrylate with C 2 -C 22 alkyl chains.

10. The lubricating oil composition according to claim 1 , where exactly one of R 1 to R 5 is a C 8 -C 7500 -polyisobutyl or C 8 -C 7500 -polyisobutenyl.

11. The lubricating oil composition according to claim 1 , where the residues R 1 to R 5 , which are not the C 8 -C 7500 -polyisobutyl or C 8 -C 7500 -polyisobutenyl, are selected from the group of hydrogen, methyl and tert-butyl.

12. The lubricating oil composition according to claim 1 , where R is selected from 1,2-ethylene, 1,2-propylene, 1,2-butylene, 1-phenyl-1,2-ethylene, 2-phenyl-1,2-ethylene.

13. The lubricating oil composition according to claim 1 , where n is 1.

14. The lubricating oil composition according to claim 1 , wherein the composition is used in an automatic transmission fluid, a manual transmission fluid, a hydraulic fluid, a grease, a gear fluid, a metal-working fluid, a crankcase engine oil or shock absorber fluid.

15. A method for improving the shear stability of a lubricating oil composition, wherein said method comprises the step of adding to a base oil, and an additive, a poly(polyisobutylenemethacrylate) copolymer (polyPIBMA) of formula (I)

wherein
R 1 to R 5 independently from each other are selected from the group consisting of hydrogen, C 1 -C 20 -alkyl, C 1 -C 20 -alkyloxy and C 8 -C 7500 -polyisobutyl and C 8 -C 7500 -polyisobutenyl,
R is an alkylene group comprising 2 to 10 carbon atoms,

R 6 is hydrogen or methyl,
R 7 is hydrogen or methyl, or COOR 8 ,
R 8 is hydrogen or C 1 -C 20 -alkyl and
n is a number from 1 to 50,
characterized in that at least one of R 1 to R 5 is a C 8 -C 7500 -polyisobutyl or C 8 -C 7500 -polyisobutenyl.

16. The lubricating oil composition according to claim 1 , wherein R is an alkyl group comprising 2 to 6 carbon atoms.

17. The lubricating oil composition according to claim 1 , wherein R is an alkyl group comprising 2 to 4 carbon atoms.

Assignees

• Basf Se

Inventors

• Csihony Szilard
• Thomas Anja
• Desantis Kevin J
• Rabbat Philippe
• Misske Andrea
• Barth Johannes
• Ranft Meik
• Mueller Peter
• Grabarse Wolfgang
• Fleckenstein Christoph

Classifications

• C10M2209/084

  Acrylate; Methacrylate · CPC title

• C10N2040/08

  Hydraulic fluids, e.g. brake-fluids · CPC title

• C10N2030/68

  Shear stability · CPC title

• C10N2040/042

  for automatic transmissions · CPC title

• C10N2030/02

  Pour-point; Viscosity index · CPC title