Mineral oil-based base oil, lubricating oil composition, equipment, lubricating method, and grease composition
AssigneeIdemitsu Kosan Co., Ltd.
InventorsShinji Aoki, Moritsugu Kasai, Asami Koga
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Abstract
The present invention provides a mineral base oil having a kinetic viscosity at 100° C. of 7 mm2/s or more and less than 10 mm2/s, a viscosity index of 100 or more, and a temperature gradient Δ|η*| complex viscosity between two temperature points of −5° C. and −15° C. of 240 mPa·s/° C. or less as measured with a rotary rheometer at an angular velocity of 6.3 rad/s. The use of the mineral base oil enables easy preparation of a lubricating oil composition and a grease composition having excellent oxidation stability while ensuring the freedom of selection of additives.
Claims6
A grease composition, comprising:
- a mineral base oil having:
- a kinetic viscosity at 100° C. of 7 mm2/s or more and less than 10 mm2/s;
- a viscosity index of 100 or more;
- a temperature gradient Δ|η*| of complex viscosity between two temperature points of −5° C. and −15° C. of 10 to 240 mPa·s/° C. or less as measured with a rotary rheometer at an angular velocity of 6.3 rad/s;
- and
- a naphthene content (% CN) of 16 to 30;
- and
- a thickener,
- wherein the grease composition comprises, based on a total mass of the grease composition:
- from 70-97% by mass of the mineral base oil;
- and
- from 3-30% by mass of the thickener, and
- wherein the mineral base oil is obtained by refining a feedstock oil comprising a petroleum-derived wax and a bottom oil, and
- wherein the thickener is one or more selected from a metal soap and a urea compound.
Dependencies are inferred from the claim text.