JP2007016172A - Lubricant base oil, method for producing the same and lubricant oil composition containing the base oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant base oil having a high viscosity index, excellent in fluidity at low temperatures, low evaporativity and low traction coefficient, a method for producing the same and a lubricant oil composition. <P>SOLUTION: The lubricant base oil comprises hydrocarbon-based oil, has ≥130 viscosity index, ≥90% paraffin (%Cp) by cyclic analysis and ≤0.04 traction coefficient at 20°C. The lubricant oil composition contains the lubricant base oil. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lubricating base oil, a process for producing the same, and a lubricating oil composition containing the base oil. More specifically, the present invention relates to a high viscosity index, excellent low-temperature fluidity, low evaporability, and a traction coefficient. The present invention relates to a low lubricating base oil, a method for producing the same, and a lubricating oil composition excellent in fuel economy using the base oil.

In general, lubricating oils are used in various fields for the purpose of essentially maintaining viscosity and preventing wear of contact members to impart lubricity. It is important for the performance of this lubricating oil to maintain an appropriate viscosity at a high temperature and fluidity at a low temperature. Recently, there has been a demand for lubricating oil compositions to save energy and save fuel by further reducing viscosity in a region where friction is not generated and reducing stirring resistance.
In recent years, high-viscosity index base oils having a viscosity index of 120 or more have been used as base oils for such energy-saving engine oils. It has been conventionally known that if the viscosity index is high, the oxidation stability is relatively improved. However, the high viscosity index base oil is generally manufactured by a solvent dewaxing method and is inferior in low-temperature fluidity. There were drawbacks. For example, Patent Document 1 discloses a high viscosity index base oil having a viscosity index of 120 or more, preferably 140 or more, but it is described that it is difficult to achieve a low pour point. When lubricating oil with inferior low-temperature fluidity is used as, for example, engine oil, the fuel efficiency at the time of low-temperature start is deteriorated. It becomes difficult to increase. Therefore, a lubricating base oil having a high viscosity index and excellent low temperature fluidity has been demanded.

The engine valve system (especially the cam-follower) is in a lubrication state in which a mixed lubrication state in which some metals are in contact and a boundary lubrication state are mixed. In this lubricated state, the oil film is exposed to high pressure, and it is desirable from the viewpoint of fuel saving to reduce the traction coefficient in this portion. However, since the high viscosity index base oil as described above contains a naphthene ring or an aromatic ring in the base oil, the traction coefficient is high, and it is difficult to improve fuel economy.
Furthermore, in order to reduce friction loss due to engine oil and to save fuel, it is an effective method to reduce the viscosity of engine oil. However, simply lowering the viscosity of the lubricating oil may increase the wear at the sliding portion and may cause environmental problems such as increased evaporation loss of the lubricating oil and deterioration of the exhaust gas properties. In addition, there are problems such as a decrease in the amount of oil and an increase in the deterioration rate of the lubricating oil.
As described above, it is not easy to obtain a lubricating base oil having high environmental performance and high fuel efficiency.

JP-A-54-70305

  The present invention has been made under such circumstances, a lubricating base oil having a high viscosity index, excellent low-temperature fluidity, low evaporability, and low traction coefficient, a method for producing the same, and the base oil. It is an object of the present invention to provide a lubricating oil composition.

As a result of intensive studies to achieve the above object, the present inventors use a hydrocarbon-based lubricating base oil having a specific viscosity index, composition, and traction coefficient. It has been found that the above problem can be solved. The present invention has been completed based on such findings.
That is, the present invention
(1) Hydrocarbon base oil having a viscosity index of 130 or more, a paraffin content (% C _P ) by ring analysis of 90% or more, and a traction coefficient at 20 ° C. of 0.04 A lubricating base oil characterized by:
(2) The method for producing a lubricating base oil according to (1) above, wherein a wax fraction having a viscosity index of 180 or more is treated in the order of an isomerization dewaxing step, a hydrofinishing step, and a vacuum distillation step. ,
(3) The method for producing a lubricating base oil according to (2), further comprising a vacuum distillation step between the isomerization dewaxing step and the hydrofinishing step,
(4) A lubricating oil composition comprising the lubricating base oil according to (1) above and the lubricating base oil produced by the method according to (2) or (3) above,
(5) The lubricating oil composition according to (4), wherein the CCS viscosity at −35 ° C. is 6200 mPa · s or less,
(6) The lubricating oil composition according to (5), wherein the NOACK value is 15% by mass or less,
(7) The lubricating oil composition according to the above (5) or (6), wherein the kinematic viscosity at 40 ° C is 35 mm ² / sec or less and the high-temperature high shear viscosity at 150 ° C is 2.6 mPa · s or more,
(8) The lubricating oil composition according to (5) or (6), wherein the kinematic viscosity at 40 ° C. is 31 mm ² / sec or less, and the high temperature high shear viscosity at 150 ° C. is 2.0 mPa · s or more,
(9) The lubricating oil composition according to any one of (4) to (8), which is for an internal combustion engine,
Is to provide.

  According to the present invention, it is possible to obtain a lubricating base oil having a high viscosity index, excellent low-temperature fluidity, low evaporability, and low traction coefficient, a method for producing the same, and a lubricating oil composition. The lubricating oil composition of the present invention includes automotive engine oil, power steering oil, automatic transmission oil (ATF), continuously variable transmission oil (CVTF), hydraulic fluid, turbine oil, compressor oil, machine tool lubricating oil, cutting. Although it can be widely applied to oil, gear oil, fluid bearing oil, rolling bearing oil, etc., it is particularly suitable for engine oil for automobiles.

The lubricating base oil of the present invention is a hydrocarbon-based lubricating base oil having a viscosity index of 130 or more, a paraffin content (% C _P ) by ring analysis of 90% or more, and at 20 ° C. The traction coefficient is 0.04 or less.
When the viscosity index is less than 130, the low temperature fluidity is lowered and the object of the present invention cannot be achieved. A preferred viscosity index is 140 or more. The above viscosity index is measured according to JIS K 2283.
The paraffin content (% C _P ) by ring analysis is 90% or more. If% _CP is less than 90%, the oxidation stability decreases. Note that the% C _P is a value measured in accordance with ASTM D-3238.
Regarding the naphthene content by ring analysis (% C _n), it is not particularly limited, is preferably 7% or less, and more preferably 3% or less. % C If _n is less than 7%, it is possible to obtain better oxidation stability.
Furthermore, the traction coefficient at 20 ° C. is 0.04 or less. The traction coefficient was measured by a two-cylinder friction test described in detail later.

The density of the lubricating base oil of the present invention varies depending on the (dynamic) viscosity of the base oil, but is lower than that of conventionally known base oils. For example, in the case of a kinematic viscosity equivalent to 100 neutral, the density of the lubricating base oil of the present invention is preferably 0.83 g / cm ³ or less, more preferably 0.82 g / cm ³ or less.
The lubricating base oil of the present invention having the above-described properties can satisfy the API (American Petroleum Institute) Group III standard.

Next, a method for producing the lubricating base oil will be described.
The method for producing the lubricating base oil in the present invention is not particularly limited, but preferably, a wax having a viscosity index of 180 or more is (a) an isomerization dewaxing step as described below, if necessary. (B) It can manufacture by processing in order of a vacuum distillation process, (c) hydrofinishing process, and (d) vacuum distillation process.
(A) Isomerization dewaxing step Wax having a viscosity index of 180 or more is used as a raw material. Furthermore, it is preferable that the kinematic viscosity at 100 ° C. is 4 to ²⁰ mm ² / s and the 10% distillation temperature in the distillation test is 380 ° C. or higher. Specifically, a wax fraction obtained by dewaxing a bottom oil obtained by hydrocracking a vacuum gas oil, a product obtained by Fischer-Tropsch synthesis, or the like can be used.
This isomerization dewaxing is performed by performing a hydrogenation treatment in the presence of a hydroisomerization catalyst in which a noble metal such as Pt or Pd is supported on a support such as SAPO (silica aluminophosphate) or zeolite.
About hydrogen partial pressure, it is 1 MPa or more normally, Preferably it is 2-22 MPa, More preferably, it is 3-21 MPa. About reaction temperature, it is 250-500 degreeC normally, Preferably it is 280-480 degreeC, More preferably, it is 300-450 degreeC. About liquid hourly space velocity (LHSV), it is 0.1-10 hr < ^-1 > normally, Preferably it is 0.3-8 hr < ^-1 >, More preferably, it is 0.5-2 hr < ^-1 >. The ratio of feed hydrogen gas, the supply Oil 1 kiloliter, usually 100 to 1000 nm ^3, preferably 200 to 800 nm ^3, more preferably 250~650Nm ^3.

(B) Vacuum distillation step This is a step of removing light fractions so that the oil produced in the previous step has a flash point of 200 to 210 ° C. by vacuum distillation, and is performed as necessary.
(C) Hydrofinishing step This hydrofinishing is carried out by using Ni / Mo, Co / Mo, Ni, etc. on the amorphous oil such as silica / alumina and alumina and the crystalline carrier such as zeolite. This is carried out by performing a hydrogenation treatment in the presence of a hydrogenation catalyst carrying a metal oxide such as / W or a noble metal such as Pt or Pd.
About hydrogen partial pressure, it is 10 MPa or more normally, Preferably it is 13-22 MPa, More preferably, it is 15-21 MPa. About reaction temperature, it is 200-350 degreeC normally, Preferably it is 250-330 degreeC, More preferably, it is 280-320 degreeC. About liquid hourly space velocity (LHSV), it is 0.1-10 hr < ^-1 > normally, Preferably it is 0.2-5 hr < ^-1 >, More preferably, it is 0.4-2 hr < ^-1 >. The ratio of feed hydrogen gas, the supply oil 1 kl, usually 100 to 1000 nm ^3, preferably 200 to 800 nm ^3, more preferably 250~650Nm ^3.
(D) Vacuum distillation step The oil produced in the previous step is adjusted by vacuum distillation so that the kinematic viscosity at 100 ° C. is 2.0 to 10.0 mm ² / s.
Through the above three or four steps, the lubricating base oil having the preferred properties in the present invention can be produced efficiently and at low cost.
The lubricating base oil of the present invention can be used in combination with other lubricating base oils and various additives depending on the purpose, including the use of engine oil, ATF, and hydraulic fluid.

  The lubricating oil composition in the present invention is a lubricating oil composition containing the lubricating base oil. This lubricating oil can provide a lubricating oil composition having the characteristics of the lubricating base oil, that is, having a high viscosity index, low temperature fluidity, and high oxidation stability.

The lubricating oil composition of the present invention preferably has a CCS viscosity at −35 ° C. (cold cranking simulator viscosity by SAE) of 6200 mPa · s or less. When the CCS viscosity at −35 ° C. is 6200 mPa · s or less, it has sufficient low-temperature fluidity, and for example, the engine startability at low temperatures is good. In addition, said CCS viscosity is measured according to JISK2010.
Further, the lubricating oil composition of the present invention preferably has a NOACK value (250 ° C.) of 15% by mass or less. If it is 15% by mass or less, the evaporation resistance is remarkably improved. The NOACK value is an index indicating evaporability and is measured according to ASTM D-5800.

The lubricating oil composition of the present invention preferably has a kinematic viscosity at 40 ° C. of 35 mm ² / sec or less and a high temperature high shear viscosity at 150 ° C. of 2.6 mPa · s or more. By satisfying this condition, fluid friction can be reduced and fuel saving performance can be improved. Further, the kinematic viscosity at 40 ° C. is preferably 31 mm ² / sec or less, and the high temperature high shear viscosity at 150 ° C. is preferably 2.0 mPa · s or more. By satisfying this condition, fluid friction can be further reduced, and fuel efficiency can be improved.

  In the lubricating oil composition of the present invention, the lubricating base oil of the present invention is used as the lubricating base oil, but other lubricating base oils may be mixed and used depending on the purpose. In that case, in the lubricating base oil of the lubricating oil composition, the content of the lubricating base oil of the present invention is preferably 60% by mass or more based on the total amount of the lubricating base oil, and more preferably 80% by mass or more. In particular, it is preferably 90% by mass or more. When the lubricating base oil of the present invention is contained in an amount of 60% by mass or more of the entire lubricating base oil, a composition that makes full use of the characteristics of the lubricating base oil of the present invention can be obtained.

The lubricant base oil other than the lubricant base oil of the present invention is not particularly limited, and a conventionally used mineral oil or synthetic oil can be used, and may be appropriately selected according to the use.
Examples of mineral oils include paraffinic mineral oils, naphthenic mineral oils, intermediate base mineral oils, and specific examples include light neutral oil, medium neutral oil, heavy neutral oil, bright stock by solvent refining or hydrorefining. And so on. On the other hand, as synthetic oil, for example, poly-α-olefin, α-olefin copolymer, polybutene, alkylbenzene, polyol ester, dibasic acid ester, polyhydric alcohol ester, polyoxyalkylene glycol, polyoxyalkylene glycol ester, polyoxyalkylene Examples include glycol ethers and cycloalkane compounds.

  In the lubricating oil composition of the present invention, additives can be appropriately blended depending on the application. As additives, those commonly used in lubricating oil compositions can be used, specifically, viscosity index improvers, pour point depressants, antioxidants, ashless dispersants, friction modifiers, Examples include metal detergents, antiwear agents, rust inhibitors, metal deactivators, demulsifiers, and antifoaming agents.

  Examples of the viscosity index improver include non-dispersed polymethacrylates, dispersed polymethacrylates, olefin copolymers (for example, ethylene-propylene copolymers), dispersed olefin copolymers, styrene copolymers. (For example, styrene-diene hydrogenated copolymer). The weight average molecular weight of these viscosity index improvers is preferably from 5,000 to 1,000,000, and more preferably from 10,000 to 800,000, for example, in dispersed and non-dispersed polymethacrylates. Moreover, 800-300,000 are preferable in an olefin type copolymer, and 10,000-200,000 are further more preferable. These viscosity index improvers can be contained alone or in any combination of two or more kinds, but the content thereof is usually in the range of 0.1 to 20% by mass on the basis of the lubricating oil composition.

  Examples of the pour point depressant include ethylene-vinyl acetate copolymer, condensate of chlorinated paraffin and naphthalene, condensate of chlorinated paraffin and phenol, polymethacrylate, polyalkylstyrene, etc. Methacrylate is preferably used. These contents are usually in the range of 0.01 to 5 mass% based on the lubricating oil composition.

  Antioxidants include amine-based antioxidants such as alkylated diphenylamine, phenyl-α-naphthylamine, alkylated phenyl-α-naphthylamine, 2,6-di-t-butylphenol, 4,4′-methylenebis (2, 6-di-t-butylphenol), isooctyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, n-octadecyl-3- (3,5-di-t-butyl-4- Phenol-based antioxidants such as hydroxyphenyl) propionate, sulfur-based antioxidants such as dilauryl-3,3'-thiodipropionate, phosphorus-based antioxidants such as phosphite, and molybdenum-based antioxidants. . These antioxidants may be contained alone or in any combination of two or more, but usually two or more combinations are preferable, and the blending amount is 0.01 to 5% by mass based on the lubricating oil composition. Is preferable, and 0.2-3 mass% is still more preferable.

Examples of the ashless dispersant include polybutenyl succinimide having a polybutenyl group having a number average molecular weight of 900 to 3,500, polybutenylbenzylamine, polybutenylamine, and derivatives thereof such as boric acid-modified products. Can be mentioned. These ashless dispersants can be contained alone or in any combination of two or more kinds, but the content is usually in the range of 0.1 to 20% by mass on the basis of the lubricating oil composition.
Examples of the friction modifier include organic molybdenum compounds, fatty acids, higher alcohols, fatty acid esters, fats and oils, amines, amides, sulfurized esters, phosphate esters, phosphite esters, phosphate ester amine salts, and the like. These viscosity index improvers can be contained alone or in any combination of two or more, but the content is usually in the range of 0.05 to 4% by mass based on the lubricating oil composition.
Examples of metal detergents include sulfonates, phenates, salicylates and naphthenates of alkali metals (sodium (Na), potassium (K), etc.) or alkaline earth metals (calcium (Ca), magnesium (Mg), etc.). Can be mentioned. These can be used alone or in combination. The total base number and the addition amount of these metal detergents can be arbitrarily selected according to the required performance of the lubricating oil, and the total base number is usually 0 to 500 mgKOH / g, preferably 20 by the perchloric acid method. -400 mgKOH / g, The compounding quantity is the range of 0.1-10 mass% normally on the basis of lubricating oil composition.

  Examples of the antiwear agent include dithiophosphate metal salts (Zn, Pb, Sb, Mo, etc.), dithiocarbamic acid metal salts (Zn, Pb, Sb, Mo, etc.), naphthenic acid metal salts (Pb, etc.), and fatty acid metal salts. (Such as Pb), boron compounds, phosphate esters, phosphites, alkyl hydrogen phosphites, phosphate ester amine salts, phosphate ester metal salts (such as Zn), disulfides, sulfurized fats and oils, sulfurized olefins, dialkyl polysulfides, diaryls Examples thereof include alkyl polysulfide and diaryl polysulfide. These antiwear agents can be contained alone or in any combination of two or more, but the content is usually in the range of 0.1 to 5% by mass based on the lubricating oil composition.

  Examples of the rust preventive agent include fatty acid, alkenyl succinic acid half ester, fatty acid soap, alkyl sulfonate, polyhydric alcohol fatty acid ester, fatty acid amine, oxidized paraffin, alkyl polyoxyethylene ether, etc. Is the range of 0.01-3 mass% on the basis of the lubricating oil composition.

Examples of the metal deactivator include benzotriazole, triazole derivatives, benzotriazole derivatives, thiadiazole derivatives and the like, and the content thereof is usually in the range of 0.01 to 3% by mass on the basis of the lubricating oil composition.
Examples of the antifoaming agent include dimethylpolysiloxane and polyacrylate.

  The lubricating oil composition of the present invention is most suitable for automobile engine oil, and is particularly suitable for 0W-20 grade in the classification system SAE (J300) of The Society of Automotive Engineers, and further for multi-grade oil with reduced viscosity, It is expected that the viscous resistance applied to the engine can be lowered and the fuel efficiency can be improved.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
Evaluation Method (1) Density: The density at 15 ° C. was measured according to JIS K2249.
(2) Kinematic viscosity: Kinematic viscosity at 40 ° C. and 100 ° C. was measured according to JIS K2283.
(3) Viscosity index: The viscosity index was measured according to JIS K2283.
(4) Noack value: The Noack value was measured according to ASTM D-5800. The measurement was performed at 250 ° C. for 1 hour.
(5) CCS viscosity: Based on JIS K2010, the CCS viscosity at −35 ° C. was measured.
(6) Traction coefficient: The traction coefficient was measured with a two-cylinder friction tester. That is, one of the cylinders of the same size in contact (diameter 40 mm, thickness 20 mm, driven type is a flat type with a curvature radius of 20 mm, and the driving side is a flat type without crowning) is continuously constant at the other rotation speed. The tangential force generated between the two cylinders, that is, the traction force, was measured by applying a weight of 147.1 N to the contact portion of both cylinders with a weight, and the traction coefficient was obtained. This cylinder was made of a mirror finish of chromium molybdenum steel SCM420, with an average weekly speed of 6.8 m / s and a maximum Hertz contact pressure of 1.24 GPa. In measuring the traction coefficient at a fluid temperature (oil temperature) of 20 ° C., the oil temperature of the oil tank was cooled to 20 ° C. with a circulating cooling device, and the traction coefficient at a slip rate of 5% was determined.
(7) Paraffin content by ring analysis; measured according to ASTM D-3238.
(8) High-temperature high-shear viscosity: High-temperature high-shear viscosity at 150 ° C. was measured in accordance with the Japan Petroleum Institute Petroleum Test Related Standard JPI-5S-36-91.
(9) Driving torque improvement rate (%) (30 ° C.): The cam shaft of a 2 liter SOHC engine was driven by a motor, and the torque applied to the cam shaft at that time was measured. The rotational speed of the camshaft was 750 rpm, and the engine oil temperature was 30 ° C. As reference oil, commercially available SL 5W-20 engine oil (kinematic viscosity (40 ° C.); 41.45 mm ² / s, kinematic viscosity (100 ° C.); 8.383 mm ² / s, viscosity index; 184, CCS viscosity (−35 ° C); 6900 mPa · s, high temperature and high shear viscosity (150 ° C); 2.62 mPa · s, Noack value: 13.0 mass%) at 30 ° C, the driving torque was measured, and Examples 4 to 7 and Comparative Example 3 And the lubricating oil composition of No. 4 was evaluated by the driving torque improvement rate (%). The larger the number, the better the driving torque and the higher fuel efficiency.

Example 1
A wax raw material A having the properties described in Table 1 obtained by Fischer-Tropsch synthesis was used, using a hydroisomerization catalyst in which platinum was supported on zeolite, a reaction temperature of 360 ° C., a pressure of 13 MPa, and LHSV of 1.0 hr. ^-1 , hydrodewaxing was performed under the conditions of a hydrogen / oil ratio of 800 NL / L. Next, it was hydrofinished under the conditions of a pressure of 13 MPa, a reaction temperature of 260 ° C., and LHSV of 1.0 hr ⁻¹ using a catalyst having Ni and W supported on an alumina support. The resulting product oil was subjected to distillation under reduced pressure into a light fraction and a base oil 1 having a target 100 ° C. viscosity of 4.5 to 5.0 mm ² / s and three fractions of a bottom fraction. The properties of the base oil 1 are shown in Table 2.

Example 2
The base oil 2 having a boiling point range narrowed and a viscosity at 100 ° C. of 4.0 to 4.5 mm ² / s was obtained by changing the vacuum distillation conditions of the product oil obtained in Example 1. The properties of the base oil 2 are shown in Table 2.

Example 3
Using a hydroisomerization catalyst, a wax raw material B having properties described in Table 1 obtained by Fischer-Tropsch synthesis was used, with a reaction temperature of 353 ° C., a pressure of 13 MPa, LHSV of 1.0 hr ⁻¹ , and a hydrogen / oil ratio. Hydrodewaxing was performed under conditions of 800 NL / L. Next, it was hydrofinished under the conditions of a pressure of 13 MPa, a reaction temperature of 260 ° C., and LHSV of 1.0 hr ⁻¹ using a catalyst having Ni and W supported on an alumina support. The resulting product oil was subjected to distillation under reduced pressure into a light fraction, a base oil 3 having a target 100 ° C. viscosity of 3.0 to 3.5 mm ² / s, and a bottom fraction and three fractions. The properties of the base oil 3 are shown in Table 2.

Comparative Example 1 and Comparative Example 2
Hydrocracking heavy vacuum oil obtained from an ordinary vacuum distillation apparatus, and wax obtained by solvent dewaxing of the bottom fraction obtained when producing naphtha to light oil; : The raw material C which has the property described in Table 1 was mixed by the ratio of 50. The raw material C was hydrodewaxed using a hydroisomerization catalyst under the conditions of a reaction temperature of 340 ° C., a pressure of 4 MPa, LHSV of 1.0 hr ⁻¹ , and a hydrogen / oil ratio of 500 NL / L. The dewaxed product oil was adjusted to 200 ° C. with a vacuum distillation apparatus, and then a catalyst having Ni and W supported on an alumina support under the conditions of a pressure of 21 MPa, a reaction temperature of 260 ° C., and LHSV 0.5 hr ⁻¹ . Hydrogenated. The obtained base oil was subjected to distillation under reduced pressure to obtain a target base oil 2 (Comparative Example 2) having a target 100 ° C. viscosity of 3.0 to 3.5 mm ² / s and a target 100 ° C. viscosity of 4.5 to 5.0 mm. ^It was fractionated into a comparative base oil 1 (Comparative Example 1) of ² / s and three fractions of a bottom fraction.

Examples 4-7, Comparative Examples 3 and 4
Lubricating oil compositions were prepared with the blending amounts shown in Table 3, and evaluated by the above evaluation methods. The results are shown in Table 3.

(note)
* 1 Viscosity index improver: Polymethacrylate (weight average molecular weight; 550,000)
* 2 Pour point depressant: polyalkyl methacrylate (weight average molecular weight; 6,000)
* 3 Antioxidant: Phenol type antioxidant (mixture of isooctyl-3- (4-hydroxy-3,5-di-t-butylphenylpropionate and dialkyldiphenylamine (nitrogen content; 4.62% by mass)) 4 Metal detergent: Calcium sulfonate (base number 300 mgKOH / g, calcium content; 12% by mass)
* 5 Ashless dispersant: polybutenyl succinimide (nitrogen content; 0.7 mass%) and boron-modified polybutenyl succinimide (boron content; 0.2 mass%, nitrogen content; 2.1) Mixture of anti-wear agent: zinc dialkyldithiophosphate (Zn content; 0.11% by mass, phosphorus content; 0.10% by mass, alkyl group; secondary butyl group and secondary hexyl group) A mixture of
* 7 Friction modifier: Molybdenum dithiocarbamate (Mo content; 4.5% by mass)
* 8 Other additives: A mixture of rust inhibitor, metal deactivator, demulsifier and antifoaming agent

  The lubricating base oil of the present invention and the lubricating oil composition using the same have a high viscosity index, excellent low-temperature fluidity, low evaporability, and a low traction coefficient. The lubricating oil composition of the present invention includes automotive engine oil, power steering oil, automatic transmission oil (ATF), continuously variable transmission oil (CVTF), hydraulic fluid, turbine oil, compressor oil, machine tool lubricating oil, cutting. Although it can be widely applied to oil, gear oil, fluid bearing oil, rolling bearing oil, etc., it is particularly suitable for engine oil for automobiles.

Claims (9)

A hydrocarbon-based lubricating base oil having a viscosity index of 130 or more, a paraffin content (% C _P ) by ring analysis of 90% or more, and a traction coefficient at 20 ° C. of 0.04 or less. A lubricating base oil characterized by that. The method for producing a lubricating base oil according to claim 1, wherein a wax fraction having a viscosity index of 180 or more is treated in the order of an isomerization dewaxing step, a hydrofinishing step, and a vacuum distillation step. The method for producing a lubricating base oil according to claim 2, further comprising a vacuum distillation step between the isomerization dewaxing step and the hydrofinishing step. A lubricating oil composition comprising the lubricating base oil according to claim 1 and the lubricating base oil produced by the method according to claim 2 or 3. The lubricating oil composition according to claim 4, wherein the CCS viscosity at −35 ° C. is 6200 mPa · s or less. The lubricating oil composition according to claim 5, wherein the NOACK value is 15% by mass or less. The lubricating oil composition according to claim 5 or 6, wherein the kinematic viscosity at 40 ° C is 35 mm ² / sec or less, and the high-temperature high shear viscosity at 150 ° C is 2.6 mPa · s or more. The lubricating oil composition according to claim 5 or 6, wherein the kinematic viscosity at 40 ° C is 31 mm ² / sec or less, and the high-temperature high shear viscosity at 150 ° C is 2.0 mPa · s or more. The lubricating oil composition according to any one of claims 4 to 8, which is used for an internal combustion engine.