Claims
- 1. A lubricant suitable for use in a diesel engine, comprising:(a) a synthetic base oil composition, said base oil overall having a kinematic viscosity of at least about 4.8×10−6m2/s (4.8 cSt) at 100° C. and a viscosity index of at least about 110; (b) a dispersant-viscosity modifier; and (c) a saligenin derivative represented by the formula wherein X comprises —CHO or —CH2OH, provided that when m is 1 or greater, one of the X groups c an be hydrogen; Y comprises —CH2— or —CH2OCH2—, and wherein such —CHO groups comprise at least about 10 mole percent of the X and Y groups; M is hydrogen, ammonium, or a valence of a metal ion, R1 is a hydrocarbyl group containing 1 to about 60 carbon atoms, m is 0 to about 10, and each p is independently 0, 1, 2, or 3, provided that at least one aromatic ring contains an R1 substituent and that the total number of carbon atoms in all R1 groups is at least 7.
- 2. The lubricant of claim 1 wherein said synthetic base oil composition comprises a polyalphaolefin oil, a synthetic ester, an alkylbenzene, or mixtures thereo.
- 3. The lubricant of claim 1 wherein the synthetic base oil composition comprises a mixture of at least one polyalphaolefin of about 4 to about 8×10−6m2/s (4-8 cSt) viscosity at 100° C., at least one C10-13 alkyl-substituted benzene, and optionally at least one synthetic monoester.
- 4. The lubricant of claim 1 wherein the synthetic base oil composition comprises multiple components and any such components individually having viscosity indices of less than 120 comprise in total no more than about 20 percent by weight of said base oil composition.
- 5. The lubricant of claim 1 wherein the synthetic base oil composition has a viscosity index of about 120 to about 160.
- 6. The lubricant of claim 1 wherein the dispersant viscosity modifier is a functionalized polymethacrylate or a functionalized olefin copolymer.
- 7. The lubricant of claim 1 wherein the amount of the dispersant viscosity modifier is about 0.5 to about 3 percent by weight of the lubricant.
- 8. The lubricant of claim 1 wherein m is 1 or greater and one of the X groups is hydrogen.
- 9. The lubricant of claim 1 wherein in (c), R1 is an alkyl group containing about 9 to about 18 carbon atoms.
- 10. The lubricant of claim 1 wherein in (c), m is about 3 to about 8.
- 11. The lubricant of claim 1 wherein in (c) the —CHO groups comprise about 20 to about 60 mole percent of the X and Y groups.
- 12. The lubricant of claim 1 wherein M is calcium or magnesium.
- 13. The lubricant of claim 1 wherein the saligenin derivative of (c) is a magnesium saligenin derivative represented by the formula wherein n in each case is 0 or 1 and is on average at least about 0.1 in the composition.
- 14. The lubricant of claim 13 wherein the saligenin derivative is an overbased salt.
- 15. The lubricant of claim 13 wherein the amount of the saligenin derivative is about 0.5 to about 4 percent by of the lubricant.
- 16. The lubricant of claim 1 further comprising at least one additive for diesel engine lubricants selected from the group consisting of dispersants, antiwear agents, detergents other than the saligenin derivative of (c), and antioxidants.
- 17. The lubricant of claim 16 wherein said lubricant contains less than about 50 parts per million by weight of chlorine.
- 18. The lubricant of claim 17 wherein said additive comprises a calcium phenate or a calcium sulfonate.
- 19. A lubricant prepared by admixing the components of claim 1.
- 20. A method for lubricating a crankcase-lubricated diesel engine comprising supplying the lubricant of claim 1 to the crankcase thereof.
Parent Case Info
This is a continuation-in-part Ser. No. 09/782,127 now U.S. Pat. No. 6,331,510 filed on Feb. 13, 2001.
US Referenced Citations (10)
Foreign Referenced Citations (5)
Number |
Date |
Country |
0 119 069 |
Sep 1984 |
EP |
0 323 086 |
Jul 1989 |
EP |
0 987 311 |
Mar 2000 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
09/782127 |
Feb 2001 |
US |
Child |
09/981057 |
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US |