Lubricating oil composition for transmissions

Patent metadata

Field	Value
Publication number	US-2017145337-A1
Application number	US-201515319055-A
Country	US
Kind code	A1
Filing date	Apr 7, 2015
Priority date	Jun 16, 2014
Publication date	May 25, 2017
Grant date	—

Abstract

A lubricating oil composition for transmissions is provided which improves fuel saving properties and has excellent metal fatigue life and heat resistance. The composition contains 50 to 97 percent by mass of (A) a mineral base oil having a 100° C. kinematic viscosity of 1.5 mm 2 /s or higher and 3.5 mm 2 /s or lower, a pour point a −25° C. or lower, a viscosity index of 105 or greater, a % C p of 85 or greater, a % C N of 2 or greater and 20 or less and a % C A of 3 or less; 3 to 10 percent by mass of (B) a monoester-hased base oil having a 100° C. kinematic viscosity of 2 mm 2 /s or higher and 10 mm 2 /s or lower; and 150 to 400 ppm by mass as phosphorus of (C) a specific sulfur-containing phosphite ester. The composition has a 100° C. kinematic viscosity of 2.5 mm 2 /s or higher and 4.0 mm 2 /s or lower.

First claim

1 . A lubricating oil composition for transmissions comprising:
a lubricating base oil comprising:
(A) a mineral base oil having a 100° C. kinematic viscosity of 1.5 mm 2 /s or higher and 3.5 mm/s or lower, a pour point of −25° C. or lower, a viscosity index of 105 or greater, a % C 2 of 85 or greater, a % C N of 2 or greater and 20 or less and a % C A of 3 or less in an amount of 50 to 97 percent by mass on the total base oil composition mass basis; and
(B) a monoester-based base oil having a 100° C. kinematic viscosity of 2 mm 2 /s or higher and 10 mm 2 /s or lower in an amount of 3 to 10 percent by mass on the total base oil composition mass basis; and
(C) a sulfur-containing phosphite ester represented by formula (1) below in an amount of 150 to 400 ppm by mass as phosphorus on the total lubricating oil composition mass basis and the composition having a 100° C. kinematic viscosity of 2.5 mm 2 /s or higher and 4.0 mm 2 /s or lower:

wherein R is a sulfur-containing hydrocarbyl group having 4 to 20 carbon atoms, and R 1 is hydrogen, a hydrocarbyl group having 4 to 20 carbon atoms or a sulfur-containing hydrocarbyl group having 4 to 20 carbon atoms.

2 . The lubricating oil composition for transmissions according to claim 1 further comprising (D) a polysulfide and/or a thiadiazole.

Assignees

• Jx Nippon Oil & Energy Corp

Inventors

• Masuda Kohei
• Komatsubara Hitoshi
• Nakao Hajime

Classifications

• C10N2030/08

  Resistance to extreme temperature · CPC title

• C10N2040/044

  for manual transmissions · CPC title

• C10N2030/06

  Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure · CPC title

• C10N2010/04

  Groups 2 or 12 · CPC title

• C10N2020/02

  Viscosity; Viscosity index · CPC title