Acrylate-olefin copolymers as high viscosity base fluids

Patent metadata

Field	Value
Publication number	US-11981877-B2
Application number	US-202318200043-A
Country	US
Kind code	B2
Filing date	May 22, 2023
Priority date	May 24, 2022
Publication date	May 14, 2024
Grant date	May 14, 2024

Abstract

Acrylate-olefin copolymers and a method for the preparation of these copolymers are provided. Lubricant compositions can contain the aforementioned copolymers. The copolymers are useful as a lubricant additive or a synthetic base fluid in a lubricating oil composition, preferably in a gear oil composition, a transmission oil composition, a hydraulic oil composition, an engine oil composition, a marine oil composition, an industrial lubricating oil composition or in grease.

First claim

The invention claimed is:

1. A copolymer, comprising:
a) 70 to 95% by weight, based on a total weight of the copolymer, of monomer units derived from an acrylate of formula (I),

wherein R 1 means a linear or branched alkyl group having from 4 to 18 carbon atoms and is selected from the group consisting of a C 4 linear alkyl group, a C 6 -C 10 linear alkyl group, a C 8 -C 18 branched alkyl group, a C 11 -C 18 linear alkyl group, and a mixture thereof, and
wherein the monomer units derived from the acrylate of formula (I) comprises
0 to 45% by weight of an acrylate of formula (I) wherein R 1 is a C 4 linear alkyl group;
0 to 95% by weight of an acrylate of formula (I) wherein R 1 is a C 6 -C 10 linear alkyl group;
0 to 95% by weight of an acrylate of formula (I) wherein R 1 is a C 8 -C 18 branched alkyl group;
0 to 45% by weight of an acrylate of formula (I) wherein R 1 is a C 11 C 18 linear alkyl group; or
a mixture thereof, based on the total weight of the copolymer,

b) 5 to 30% by weight, based on the total weight of the copolymer, of monomer units derived from at least one non-functionalized alpha-olefin of formula (II),

wherein R 2 means a linear alkyl group having from 2 to 4 carbon atoms, and wherein the copolymer has a weight-average molecular weight from 5,000 to 35,000 g/mol according to DIN 55672-1.

2. The copolymer according to claim 1 , wherein the copolymer comprises from 75 to 95% by weight of monomer units a) derived from the acrylate of formula (I), based on the total weight of the copolymer.

3. The copolymer according to claim 1 , wherein the copolymer comprises from 5 to 25% by weight of monomer units b) derived from the at least one non-functionalized alpha-olefin of formula (II), based on the total weight of the copolymer.

4. The copolymer according to claim 1 , wherein the copolymer has a kinematic viscosity from 100 to 1,000 mm 2 /s at 100° C. according to ASTM D 445.

5. The copolymer according to claim 1 , wherein the at least one non-functionalized alpha-olefin of formula (II) is selected from the group consisting of butene, hexene, and a mixture thereof.

6. The copolymer according to claim 1 , wherein the amount of the acrylate of formula (I) wherein R 1 is a C 4 linear alkyl group is 0 to 40% by weight, based on the total weight of the copolymer.

7. The copolymer according to claim 1 , wherein the acrylate of formula (I) is selected from the group consisting of butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, 2-propylheptyl acrylate, isononyl acrylate, lauryl acrylate, and a mixture thereof.

8. The copolymer according to claim 1 , wherein the copolymer further comprises 0 to 20% by weight of monomer units derived from monomer c) selected from the group consisting of methacrylamides, fumarates, maleates, (meth)acrylates other than the acrylate of formula (I), and a mixture thereof, based on the total weight of the copolymer.

9. The copolymer according to claim 1 , wherein the total amount of monomer units derived from monomers a) and b) in the copolymer sums up to 80% by weight or more, based on the total weight of the copolymer.

10. The copolymer according to claim 8 , wherein the total amount of monomer units derived from monomers a), b), and c) in the copolymer sums up to 90% by weight or more, based on the total weight of the copolymer.

11. The copolymer according to claim 1 , wherein the copolymer has a weight-average molecular weight from 7,000 to 25,000 g/mol, according to DIN 55672-1.

12. The copolymer according to claim 1 , wherein the copolymer has a polydispersity index from 1.0 to 3.5.

13. A method for the preparation of the copolymer as defined in claim 1 , the method comprising:
i) providing a monomer composition, and
ii) initiating radical polymerization in the monomer composition to obtain the copolymer.

14. A lubricant composition, comprising:
one or more base oil, and
at least one copolymer according to claim 1 .

15. A method, comprising:
adding the copolymer according to claim 1 , as a lubricant additive or synthetic base fluid, to a lubricating oil composition.

16. The method according to claim 15 , wherein the lubricating oil composition is a gear oil composition, a transmission oil composition, a hydraulic oil composition, an engine oil composition, a marine oil composition, an industrial lubricating oil composition, or grease.

17. The copolymer according to claim 4 , wherein the copolymer has a kinematic viscosity from 100 to 500 mm 2 /s at 100° C. according to ASTM D 445.

18. The copolymer according to claim 8 , wherein the copolymer comprises 0 to 10% by weight of the monomer units derived from monomer c), based on the total weight of the copolymer.

19. The copolymer according to claim 9 , wherein the total amount of monomer units derived from monomers a) and b) in the copolymer sums up to 90% by weight or more, based on the total weight of the copolymer.

20. The copolymer according to claim 10 , wherein the total amount of monomer units derived from monomers a), b), and c) in the copolymer sums up to 100% by weight, based on the total weight of the copolymer.

21. A method according to claim 13 , wherein a total amount of radical initiator used relative to the total weight of the monomer composition is 0.01 to 1% by weight.

22. The lubricant composition of claim 14 , comprising 1 to 95% of the at least one base oil and 5 to 99% by weight of the at least one copolymer.

Assignees

• Evonik Operations Gmbh

Inventors

• Schweissinger Emily Clare
• Maier Stefan Karl
• Nothdurft Katja
• Gross-Onnebrink Yvonne
• Janssen Dieter
• Pletsch Holger
• Hilf Stefan
• Kleinschmidt Denise
• Babik Sebastian

Classifications

• C10M145/14 Primary

  Acrylate; Methacrylate · CPC title

• C08F220/1808

  C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate · CPC title

• C08F220/1809

  C9-(meth)acrylate · CPC title

• C10M169/041

  the additives being macromolecular compounds only · CPC title

• C08F2800/20

  as weight or mass percentages · CPC title