Controlled radical acrylic copolymer thickeners
View Patent ↗The present invention relates to acrylic block copolymers synthesized by a controlled radical process, and their use as thickeners in oil-based compositions. The acrylic copolymers are especially useful as viscosity index improvers in lubricating oil.
1. A thickened oil composition comprising
a) from 99.95 to 60 weight percent of one or more oils; and
b) from 0.05 to 40 weight percent of a block copolymer, having at least one acrylic block, synthesized by controlled radical polymerization.
2. The thickened oil composition of claim 1 comprising from 0.01 to 20 weight percent of said block copolymer.
3. The thickened oil composition of claim 1 wherein said oil composition is a lubricating oil composition.
4. The thickened oil composition of claim 1 wherein said block copolymer is an amphiphilic block copolymer.
5. The thickened oil of claim 4 wherein said amphiphilic block copolymer comprises:
1) at least one oil-soluble polymer block having a solubility parameter of from 14 to 18 (J/m 3 ) 1/2 ; and
2) at least one non-oil soluble polymer block having a solubility parameter of greater than 18 (J/m 3 ) 1/2 .
6. The thickened oil composition of claim 5 wherein said non-oil soluble block has a solubitity parameter of greater than 20 (J/m 3 ) 1/2 .
7. The thickened oil of claim 1 wherein said block copolymer is formed by a nitroxide-mediated, controlled radical polymerization process.
8. The thickened oil of claim 1 wherein said acrylic block polymer is formed from all acrylic monomers.
9. The thickened oil of claim 5 wherein said non-oil soluble polymer block comprises poly(methyl aerylate) or polystyrene.
10. The thickened oil composition of claim 1 , wherein said block copolymer comprises micelles of block copolymers.
11. The thickened oil composition of claim 2 wherein said oil composition has a viscosity index of greater than 150.
12. The thickened oil composition of claim 9 wherein said viscosity index is greater than 200.
13. The thickened oil composition of claim 10 wherein said viscosity index is greater than 250.
14. The thickened oil of claim 1 wherein said oil composition comprises a hydraulic fluid, a transmission fluid, a gear oil, a motor oil, a cosmetic formulation, or a personal care formulation.
15. The thickened oil of claim 1 wherein said block copolymers comprise at least 90 mole percent of one or more acrylic monomers.
16. The thickened oil of claim 1 wherein said acrylic block comprises at least 95 mole percent of one or more acrylic monomers.
17. The thickened oil composition of claim 3 further comprising detergents, anti-foaming agents, and anti-corrosion agents.
18. The thickened oil composition of claim 1 wherein said block copolymer is multifunctional.
19. A thickened oil composition comprising
a) from 99.95 to 60 weight percent of one or more oils; and
b) from 0.05 to 40 weight percent of a block copolymer, having at least one block consisting essentially of acrylic monomers synthesized by controlled radical polymerization.
20. The thickened oil composition of claim 19 wherein said one block consisting essentially of acrylic monomers comprises at least 90 mole percent acrylic monomers.
21. The thickened oil composition of claim 19 wherein said oil composition is a lubricating oil composition.
22. The thickened oil composition of claim 19 wherein said block copolymer is an amphiphilic block copolymer.
23. The thickened oil of claim 22 wherein said amphiphilic block copolymer comprises:
1) at least one oil-soluble polymer block having a solubility parameter of from 14 to 18 (J/m 3 ) 1/2 ; and
2) at least one non-oil soluble polymer block having a solubility parameter of greater than 18 (J/m 3 ) 1/2 .
24. The thickened oil composition of claim 23 wherein said non-oil soluble block has a solubility parameter of greater than 20 (J/m 3 ) 1/2 .
25. The thickened oil of claim 19 wherein said block copolymer is formed by a nitroxide-mediated, controlled radical polymerization process.
26. The thickened oil of claim 19 wherein said one block consisting essentially of acrylic block polymer is formed from all acrylic monomers.
27. The thickened oil of claim 23 wherein said non-oil soluble polymer block comprises poly(methyl acrylate) or polystyrene.
28. The thickened oil composition of claim 19 , wherein said block copolymer comprises micelles of block copolymers.
29. The thickened oil composition of claim 20 wherein said oil composition has a viscosity index of greater than 150.
30. The thickened oil composition of claim 27 wherein said viscosity index is greater than 200.
31. The thickened oil composition of claim 28 wherein said viscosity index is greater than 250.
32. The thickened oil of claim 19 wherein said oil composition comprises a hydraulic fluid, a transmission fluid, a gear oil, a motor oil, a cosmetic formulation, or a personal care formulation.
33. The thickened oil of claim 19 wherein said one block consisting essentially of acrylic monomers comprise at least 90 mole percent of one or more acrylic monomers.
34. The thickened oil composition of claim 19 further comprising detergents, anti-foaming agents, and anti-corrosion agents.
35. The thickened oil composition of claim 19 wherein said block copolymer is multifanctional.
36. The thickened oil of claim 19 wherein said one block consisting essentially of acrylic monomers comprises at least 95 mole percent of one or more acrylic monomers.