Lubricating oil composition

• US 7,838,470 B2
• Filed: 07/30/2004
• Issued: 11/23/2010
• Est. Priority Date: 08/07/2003
• Status: Active Grant

• Current Assignee: Infineum International Limited (Infineum)
• Original Assignee: Infineum International Limited (Infineum)
• Inventors: Robson, Robert, Shaw, Robert W., Bell, Ian A. W.
• Primary Examiner(s): Caldarola; Glenn
• Assistant Examiner(s): GOLOBOY, JAMES C
• Application Number:
  US10/909,141
• Publication Number:
  US 20050070444A1
• Time in Patent Office: 2,307 Days
• Field of Search: 508/110, 508/291, 508/591
• US Class Current: 508/110
• CPC Class Codes: C10M 167/00 Lubricating compositions characterised by the additive being a mixture of a macromolecular compound, a non-macromolecular compound and a compound of unknown or incompletely defined constitution, each of these compounds being essential
• CPC Class Codes: C10M 2203/065 used as base material

Abstract

A multigrade crankcase lubricating oil composition comprising a mineral oil-based basestock of lubricating viscosity in a major amount and a non-hydrogenated olefin polymer in a minor amount. The lubricating oil composition also comprises a dispersant, a metal detergent, one or more other additives, and a viscosity modifier.

Claims

1. A multigrade crankcase lubricating oil composition having a sulfated ash content of at least 0.2 mass %, comprising, or made by admixing:

(A) a major amount of oil of lubricating viscosity, at least 50% by mass of which is Group III mineral oil, and no greater than 25% by mass of which is a Group I, Group II or Group IV basestock; and

minor amounts of;

(B) a non-hydrogenated olefin polymer in an amount of 1 to 15 mass %, based on the mass of the oil composition, said polymer having a number average molecular weight in the range of 100 to 5,000;

(C) a dispersant;

(D) a metal detergent;

(E) one or more other lubricant additive components selected from anti-oxidants, anti-wear agents and friction modifiers, and

(F) a viscosity modifier.

2. The composition as claimed in claim 1 wherein the non-hydrogenated olefin polymer has at most 10% of the polymer chains possessing a terminal double bond.

3. The composition as claimed in claim 1 wherein the number average molecular weight of the non-hydrogenated olefin polymer is in the range of 300 to 3000.

4. The composition as claimed in claim 1 wherein the non-hydrogenated olefin polymer is derived from C3 to C8 olefins.

5. The composition as claimed in claim 1 wherein the non-hydrogenated olefin polymer has a kinematic viscosity at 100°

C. of at least 9 mm²s<sup>−

1</sup>.

6. The composition as claimed in claim 1 wherein the composition has a phosphorus content of 0.005 to 0.08 mass %;

a sulfur content of 0.05 to 0.4 mass %; and

gives a sulfated ash content of at most 1.0 mass %, each based on the mass of the oil composition.

7. A method of lubricating a compression-ignited internal combustion engine comprising operating the engine and lubricating the engine with a lubricating oil composition as claimed in claim 1.

8. A method of improving piston cleanliness of a compression-ignited internal combustion engine comprising adding to the engine a lubricating oil composition as claimed in claim 1.

9. A compression-ignited internal combustion engine, lubricated with a lubricating oil composition as claimed in claim 1.

10. The composition as claimed in claim 1 comprising 3 to 8 mass % of said non-hydrogenated olefin polymer.

11. The composition as claimed in claim 2 wherein 5 to 10% of the polymer chains of said non-hydrogenated olefin polymer possess a terminal double bond.

12. The composition as claimed in claim 3 wherein the number average molecular weight of the non-hydrogenated olefin polymer is in the range of 800 to 2500.

13. The composition as claimed in claim 4 wherein the non-hydrogenated olefin polymer is derived from butane or iso-butene.

14. The composition as claimed in claim 5 wherein the non-hydrogenated olefin polymer has a kinematic viscosity at 100°

C. of at 150 to 3000 mm²s<sup>−

1</sup>.

15. The composition as claimed in claim 1 wherein the composition has a phosphorus content of 0.01 to 0.07 mass %;

a sulfur content of 0.1 to 0.3 mass %; and

gives a sulfated ash content of 0.2 to 0.8 mass %, each based on the mass of the oil composition.

16. The composition as claimed in claim 1 wherein the composition has a phosphorus content of 0.03 to 0.06 mass %;

a sulfur content of 0.15 to 0.2 mass %; and

gives a sulfated ash content of 0.3 to 0.6 mass %, each based on the mass of the oil composition.