Lubricating oil

• US 20060105921A1
• Filed: 10/31/2003
• Published: 05/18/2006
• Est. Priority Date: 11/05/2002
• Status: Abandoned Application

• Current Assignee: Nippon Oil Corporation (ENEOS Holdings, Inc.)
• Original Assignee: Nippon Oil Corporation (ENEOS Holdings, Inc.)
• Inventors: Arimoto, Naozumi, Okawa, Tetsuo
• Application Number:
  US10/533,710
• Publication Number:
  US 20060105921A1
• Time in Patent Office: Days
• US Class Current: 508/189
• CPC Class Codes: C10M 161/00 Lubricating compositions characterised by the additive being a mixture of a macromolecular compound and a non-macromolecular compound, each of these compounds being essential
• CPC Class Codes: C10M 169/044 the additives being a mixture of non-macromolecular and macromolecular compounds
• CPC Class Codes: C10M 2203/1006 used as base material
• CPC Class Codes: C10M 2209/084 Acrylate; Methacrylate
• CPC Class Codes: C10M 2209/086 polycarboxylic, e.g. maleic acid
• CPC Class Codes: C10M 2215/04 having amino groups bound to acyclic or cycloaliphatic carbon atoms
• CPC Class Codes: C10M 2215/28 Amides; Imides
• CPC Class Codes: C10N 2020/02 Viscosity; Viscosity index
• CPC Class Codes: C10N 2030/02 Pour-point; Viscosity index
• CPC Class Codes: C10N 2030/06 Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2040/042 for automatic transmissions
• CPC Class Codes: C10N 2040/045 for continuous variable transmission [CVT]
• CPC Class Codes: C10N 2060/14 by boron or a compound containing boron

Abstract

The present invention provides a lubricating oil composition which has a low viscosity and is capable of maintaining an anti-wear characteristic at the initial use thereof and after the long-term use thereof, in particular, a lubricating oil composition suitable for automatic transmissions or continuously variable transmissions by incorporating, into (A) a lubricant base oil comprising a mineral oil, a synthetic oil or a mixture thereof, (B) a nitrogen-containing compound having at least one alkyl group or alkenyl group having a number-average molecular weight of 900 or more and/or a derivative thereof in an amount of 0.01 to 0.20% by mass in terms of the content of nitrogen of the total of the composition, and (C) a viscosity index improver having a weight-average molecular weight of 40,000 or less, so as to set the viscosity index of the composition to 160 or more and set the kinematic viscosity of the composition into the range of 20 to 30 mm²/s at 40° C.

Claims

1. A lubricating oil composition which is obtained by incorporating, into (A) a lubricant base oil comprising a mineral oil, a synthetic oil or a mixture thereof,

(B) a nitrogen-containing compound having at least one alkyl group or alkenyl group having a number-average molecular weight of 900 or more and/or a derivative thereof in an amount of 0.01 to 0.20% by mass in terms of the content of nitrogen of the total of the composition, and

(C) a viscosity index improver having a weight-average molecular weight of 40,000 or less, so as to set the viscosity index of the composition to 160 or more and set the kinematic viscosity of the composition into the range of 20 to 30 mm²/s at 40°

C.

2. The lubricating oil composition according to claim 1, wherein the (B) component is a nitrogen-containing compound having two alkyl groups or alkenyl groups having a number-average molecular weight of 1200 or more and/or a derivative thereof.

3. The lubricating oil composition according to claim 1 or 2, which essentially comprises, as the (B) component, a boron-modified compound of a nitrogen-containing compound having at least one alkyl group or alkenyl group having a number-average molecular weight of 900 or more in an amount of 0.002% or more by mass in terms of the content of boron of the total of the composition.

4. The lubricating oil composition according to claim 3, wherein the boron-modified compound is a boron-modified compound of a nitrogen-containing compound having at least one alkyl group or alkenyl group having a number-average molecular weight of 1200 or more.

5. The lubricating oil composition according to claim 3, wherein the boron-modified compound is a boron-modified compound of a nitrogen-containing compound having two alkyl groups or alkenyl groups having a number-average molecular weight of 1200 or more.

6. The lubricating oil composition according to claim 3, wherein the boron-modified compound is a boron-modified compound of a nitrogen-containing compound having two alkyl groups or alkenyl groups having a number-average molecular weight of 1700 or more.

7. The lubricating oil composition according to any one of claims 3 to 6, wherein the ratio by mass of boron to nitrogen (B/N ratio) in the boron-modified compound is from 0.01 to 3.

8. The lubricating oil composition according to claim 1, wherein the (B) component comprises a boron-modified compound of a bis type succinimide having a poly(iso)butenyl group having a number-average molecular weight of 2000 or more.

9. The lubricating oil composition according to claim 1, wherein the (B) component comprises both of a bis type succinimide having a poly(iso)butenyl group having a number-average molecular weight of 900 or more and less than 2000 and boron-modified compounds of a bis type succinimide having a poly (iso) butenyl group having a number-average molecular weight of 2000 or more.

10. The lubricating oil composition according to any one of claims 1 to 9, which is used in an automatic transmission or a continuously variable transmission.

11. Use of the lubricating oil composition according to any one of claims 1 to 9 in an automatic transmission or a continuously variable transmission.

12. A method for maintaining the anti-wear characteristic of an automatic transmission or a continuously variable transmission by use of the lubricating oil composition according to any one of claims 1 to 9.