Lubricant oil compositions for automotive gears
AssigneeMitsui Chemicals, Inc.
InventorsShota Abe, Terufumi Suzuki
Life of this patent
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Abstract
A lubricant oil composition for automotive gears includes a lubricant base oil including a mineral oil having a kinematic viscosity at 100° C. of 2.0 to 6.5 mm2/s, a viscosity index of not less than 105 and a pour point of not more than −10° C., and/or a synthetic oil having a kinematic viscosity at 100° C. of 1.0 to 6.5 mm2/s, a viscosity index of not less than 120 and a pour point of not more than −30° C.; and an ethylene/α-olefin copolymer having an ethylene content of 55 to 85 mol %, a kinematic viscosity at 100° C. of 10 to 200 mm2/s, a molecular weight distribution of not more than 2.2, and a melting point in the range of −30° C. to −60° C. The lubricant oil composition for automotive gears has a kinematic viscosity at 100° C. of 4.0 to 9.0 mm2/s.
Claims5
A lubricant oil composition for automotive gears, comprising:
- a lubricant base oil comprising a mineral oil (A) having characteristics (A1) to (A3) described below, and/or a synthetic oil (B) having characteristics (B1) to (B3) described below;
- and an ethylene/α-olefin copolymer (C) having characteristics (C1) to (C5) described below, the lubricant oil composition having a kinematic viscosity at 100° C. of 4.0 to 9.0 mm2/s,
- (A1) the kinematic viscosity at 100° C. is 2.0 to 6.5 mm2/s,
- (A2) the viscosity index is not less than 105,
- (A3) the pour point is not more than −10° C.,
- (B1) the kinematic viscosity at 100° C. is 1.0 to 6.5 mm2/s,
- (B2) the viscosity index is not less than 120,
- (B3) the pour point is not more than −30° C.,
- (C1) the ethylene content is in the range of 55 to 85 mol %,
- (C2) the kinematic viscosity at 100° C. is 10 to 200 mm2/s,
- (C3) the molecular weight distribution (Mw/Mn) for the molecular weight measured by gel permeation chromatography (GPC) with reference to polystyrene is not more than 2.2,
- (C4) the pour point is not more than −10° C.,
- (C5) the melting point has a peak in the range of −30° C. to −60° C. and gives a heat of fusion (ΔH) of not less than 9.1 J/g and not more than 25 J/g as measured by differential scanning calorimetry (DSC).
Dependencies are inferred from the claim text.