Lubricant base oil, method for production thereof, and lubricant oil composition
The lubricating base oil of the invention is characterized by having an urea adduct value of not greater than 4% by mass and a viscosity index of 100 or greater. The process for production of a lubricating base oil according to the invention is characterized by comprising a step of hydrocracking/hydroisomerization of a stock oil containing normal paraffins, until the obtained treatment product has an urea adduct value of not greater than 4% by mass and a viscosity index of 100 or greater. A lubricating oil composition according to the invention is characterized by comprising the lubricating base oil of the invention.
1. A lubricating base oil having an urea adduct value of not greater than 4% by mass and a viscosity index of 100 or greater, and comprising a saturated component that contains cyclic and acyclic components, wherein the saturated component content is 90 wt % or greater based on the total weight of the lubricating base oil, and wherein the proportion of cyclic saturated components among the saturated components is 0.1-50 wt %.
2. A lubricating oil composition comprising the lubricating base oil according to claim 1 .
3. The lubricating base oil according to claim 1 , wherein the urea adduct value is not greater than 3.5% by mass.
4. The lubricating base oil according to claim 1 , wherein the urea adduct value is not greater than 3% by mass.
5. The lubricating base oil according to claim 1 , wherein the urea adduct value is not greater than 2.5% by mass.
6. The lubricating base oil according to claim 1 , wherein the viscosity index is 110 or greater.
7. The lubricating base oil according to claim 1 , wherein the viscosity index is 120 or greater.