Random copolymers of acrylates as polymeric friction modifiers, and lubricants containing same
A random copolymer suitable for reducing friction in lubricant compositions is disclosed. The random copolymer can include a short chain acrylate, a long chain acrylate, and a polar acrylate. The random copolymer can have a ratio of short chain acrylate to long chain acrylate of 0 to 2, and a molecular weight number of 1000 to 10000. The disclosure can include a lubricant containing a base oil and the random copolymer. A process for preparing the random copolymer and polymeric friction modifiers is also disclosed.
1. A random copolymer obtained from polymerizing an acrylate monomer composition, wherein the monomer composition comprises:
a) from about 5 to about 55 mole % of at least one short chain acrylate of Formula (I),
in which R a is hydrogen or methyl, and R 1 is a linear or branched C 1 to C 10 alkyl radical;
b) from about 0 to less than about 75 mole % of at least one long chain acrylate of Formula (II),
in which R b is hydrogen or methyl, and R 2 is a linear or branched C 11 to C 15 alkyl radical;
c) from about 0 to less than about 75 mole % of at least one long chain acrylate of Formula (III),
in which R c is hydrogen or methyl, and R 3 is a linear or branched C 16 to C 30 alkyl radical; and
d) from about 5 to about 50 mole % of at least one polar acrylate of Formula (IV),
in which R d is hydrogen or methyl, A is a linear or branched C 2 to C 6 alkyl radical, aromatic radical, or a polyether of the formula (—CHR 4 CH 2 —O—) n where R 4 is hydrogen or methyl and n is from 1 to 10; and X is COOH or OH;
wherein,
at least one of R a , R b , R c , and R d is methyl;
the long chain acrylate of component b) and component c) together total from about 35 mole % to about 75 mole % of the acrylate monomers;
the ratio of short chain acrylate to long chain acrylate is from about 0.05 to about 2; and
the copolymer has an M n of 1000 to 8000 g/mol.
2. The random copolymer of claim 1 , where each of R a , R b , R c , and R d is methyl.
3. The random copolymer of claim 1 , wherein R 1 is methyl.
4. The random copolymer of claim 1 , comprising at least about 5 to about 45 mole % of the short chain acrylate.
5. The random copolymer of claim 1 , wherein M n is 2000 to 8000 g/mol.
6. The random copolymer of claim 1 , wherein R 2 is a linear or branched C 12 to C 14 alkyl radical, and R 3 is a linear or branched C 16 to C 20 alkyl radical.
7. The random copolymer of claim 1 , wherein A is a linear or branched C 2 to C 4 alkyl radical or a polyether of the formula (—CHR 4 CH 2 —O—) n where R 4 is hydrogen or methyl and n=1 to 4.
8. The random copolymer of claim 1 , wherein A is a —CH 2 CH 2 —.
9. The random copolymer of claim 1 , comprising from about 10 to about 50 mole % of the polar acrylate.
10. The random copolymer of claim 1 , comprising from about 35 to about 70 mole % of the long chain acrylate of component b) and component c) together.
11. The random copolymer of claim 1 , wherein the ratio of short chain acrylate to long chain acrylate is about 0.3 to about 1.5.
12. The random copolymer of claim 1 , wherein
R 1 is methyl or butyl;
R 2 is lauryl-myristyl or lauryl;
R 3 is cetyl-eicosyl; and
A-X is 2-hydroxyethyl.
13. The random copolymer of claim 12 , wherein the M n is 2000 to 8000 g/mol and the ratio of short chain acrylate to long chain acrylate is about 0.1 to about 1.5.
14. A lubricating oil composition, comprising:
a base oil, and
at least one additive having friction-modifying properties;
wherein the at least one additive having friction-modifying properties is a random copolymer obtained from polymerizing an acrylate monomer composition, the monomer composition comprising
a) from about 5 to about 55 mole % of at least one short chain acrylate of Formula (I),
in which R a is hydrogen or methyl, and R 1 is a linear or branched C 1 to C 10 alkyl radical;
b) from about 0 to less than about 75 mole % of at least one long chain acrylate of Formula (II),
in which R b is hydrogen or methyl, and R 2 is a linear or branched C 11 to C 15 alkyl radical;
c) from about 0 to less than about 75 mole % of at least one long chain acrylate of Formula (III),
in which R c is hydrogen or methyl, and R 3 is a linear or branched C 16 to C 30 alkyl radical; and
d) from about 5 to about 50 mole % of at least one polar acrylate of Formula (IV),
in which R d is hydrogen or methyl, A is a linear or branched C 2 to C 6 alkyl radical, aromatic radical, or a polyether of the formula (—CHR 4 CH 2 —O—) n where R 4 is hydrogen or methyl and n is from 1 to 10; and X is COOH or OH;
wherein,
at least one of R a , R b , R c , and R d is methyl;
the long chain acrylate of component b) and component c) together total from about 35 mole % to about 75 mole % of the acrylate monomers;
the ratio of short chain acrylate to long chain acrylate is from about 0.05 to about 2; and
the copolymer has an M n of 1000 to 8000 g/mol.
15. The lubricating oil composition of claim 1 , where each of R a , R b , R c , and R d is methyl.
16. The lubricating oil composition of claim 14 , wherein R 1 is methyl.
17. The lubricating oil composition of claim 14 , comprising at least about 5 to about 45 mole % of the short chain acrylate.
18. The lubricating oil composition of claim 14 , wherein M n is 2000 to 8000 g/mol.
19. The lubricating oil composition of claim 14 , wherein R 2 is a linear or branched C 12 to C 14 alkyl radical, and R 3 is a linear or branched C 16 to C 20 alkyl radical.
20. The lubricating oil composition of claim 14 , wherein A is a linear or branched C 2 to C 4 alkyl radical or a polyether of the formula (—CHR 4 CH 2 —O—) n , where R 4 is hydrogen or methyl and n=1 to 4.
21. The lubricating oil composition of claim 14 , wherein A is a —CH 2 CH 2 —.
22. The lubricating oil composition of claim 14 , comprising from about 10 to 50 mole % of the polar acrylate.
23. The lubricating oil composition of claim 14 , comprising from about 35 to about 70 mole % of the long chain acrylate of component b) and component c) together.
24. The lubricating oil composition of claim 14 , wherein the ratio of short chain acrylate to long chain acrylate is about 0.3 to about 1.5.
25. The lubricating oil composition of claim 14 , wherein
R 1 is methyl or butyl;
R 2 is lauryl-myristyl or lauryl;
R 3 is cetyl-eicosyl; and
A-X is 2-hydroxyethyl.
26. The lubricating oil composition of claim 25 , wherein the M n is 2000 to 8000 g/mol and the ratio of short chain acrylate to long chain acrylate is about 0.1 to about 1.5.
27. The random copolymer of claim 1 , wherein:
R 1 is a linear or branched C 1 to C 6 alkyl radical;
R 2 is a linear or branched C 12 to C 14 alkyl radical;
R 3 is a linear or branched C 16 to C 20 alkyl radical; and
A is a linear or branched C 2 to C 6 alkyl radical.
28. The random copolymer of claim 1 , wherein each of R 1 , R 2 , R 3 , and A are linear.
29. The lubricating oil composition of claim 14 , wherein:
R 1 is a linear or branched C 1 to C 6 alkyl radical;
R 2 is a linear or branched C 12 to C 14 alkyl radical;
R 3 is a linear or branched C 16 to C 20 alkyl radical; and
A is a linear or branched C 2 to C 6 alkyl radical.
30. The lubricating oil composition of claim 29 , wherein R 1 , R 2 , R 3 , and A are linear.