JP5968273B2 - Lubricating oil composition for continuously variable transmission - Google Patents

Description

  The present invention relates to a lubricating oil composition for a continuously variable transmission, and more particularly to a lubricating oil composition that is highly fuel efficient and suitable for a metal belt type continuously variable transmission for automobiles.

  In recent years, there has been an urgent need to save energy in automobiles, construction machinery, agricultural machinery, etc., that is, to save fuel, in response to environmental issues such as reducing carbon dioxide emissions. Engines, transmissions, final reduction gears, compression Devices such as machines and hydraulic devices are strongly required to contribute to energy saving.

As for transmissions, the use of continuously variable transmissions is being expanded as one of the means for reducing fuel consumption. This is to maximize fuel efficiency by operating the device under the most efficient operating conditions of the internal combustion engine.
Further, the continuously variable transmission has also been improved in efficiency by being lighter and smaller. With this increase in efficiency, fuel consumption is also required for the lubricating oil used. On the other hand, in general, means for reducing agitation resistance and friction resistance of a torque converter, a wet clutch, a gear bearing mechanism, an oil pump, etc. by lowering the viscosity of the lubricating oil or suppressing an increase in viscosity at a low temperature Has been taken.

  However, the lubricating oil used in these is also used as a medium for hydraulic control devices, and excessively low viscosity results in poor lubrication such as wear and seizure due to insufficient oil film thickness, oil pumps and control valves. Due to oil leakage from the etc., there is a problem that sufficient hydraulic pressure cannot be generated. In particular, in order to suppress the increase in viscosity at low temperatures, it is usual to add a polymer additive, that is, a viscosity index improver, to the base oil, but even if the new oil has an appropriate viscosity, As the polymer additive is used, the viscosity of the polymer additive decreases due to shearing, so that the proper viscosity cannot be maintained.

  For this reason, the conventional technology maintains performance such as shear stability and lubricating oil life by increasing the viscosity of the base oil while reducing the viscosity of the lubricating oil composition to improve fuel efficiency. By increasing the shear (HTHS) viscosity, it was decided to provide an automatic transmission fluid with improved oil film retention performance, excellent wear resistance, pitting resistance, etc., good shear stability, and excellent low-temperature viscosity characteristics. (For example, refer to Patent Document 1). However, this makes it impossible to fully meet the recent demand for further fuel saving.

JP 2009-096925 A

  The present invention has been made in view of such circumstances, and its purpose is to maintain the necessary viscosity of the lubricating oil composition throughout the period in which the device is used, while being low viscosity that exhibits fuel economy. In addition, by maintaining a high coefficient of friction between metals, it has a high power transmission force and has the friction characteristics and shudder prevention properties of a wet clutch required for a transmission, while realizing low fuel consumption with a low traction coefficient. A lubricating oil composition for a step transmission is provided.

  As a result of investigations to solve the above problems, the present inventors have found that a lubricating oil composition in which a specific base oil and a specific additive are selected can solve the above problems, thereby completing the present invention. It came.

That is, in the present invention, the product (EC × V40) of the weight percent (EC (% by weight)) of the saturated cyclic component and the kinematic viscosity (V40 (mm ² / s)) at 40 ° C. based on the total amount of the base oil is 500 or less. Yes, a base oil whose kinematic viscosity at 100 ° C. is adjusted to 3.6 to 4.1 mm ² / s, (B) 0.01 to 0.03% by mass with phosphorus compound as the amount of phosphorus element, (C ) Calcium salicylate and / or calcium sulfonate is contained in an amount of 0.03 to 0.05% by mass as the amount of calcium element, and the elemental ratio (P / Ca) of phosphorus and calcium in the lubricating oil composition is 0.3 to 0.00. (D) 0.001 to 0.008% by mass of boron-modified ashless dispersant as the amount of boron element, and (E) 0.01 to 2% by mass of a friction modifier based on the total amount of the composition, 100 ° C. of the lubricating oil composition Viscosity of 5.2~5.6mm ² / s, the continuously variable transmission lubricating oil composition characterized by a viscosity index of 165 or more.

  The lubricating oil composition for continuously variable transmissions of the present invention can maintain the required viscosity of the lubricating oil composition throughout the period in which the equipment is used, while maintaining a low viscosity, and also maintains a high coefficient of friction between metals. Therefore, it has a high power transmission force, has the wet clutch friction characteristics and anti-shudder properties necessary for the transmission, and can realize further fuel saving by a low traction coefficient.

The present invention will be described below.
The base oil in the present invention has a product (EC × V40) of 500% or less of the weight percent (EC (% by weight)) of the saturated cyclic component on the basis of the total amount and the kinematic viscosity (V40 (mm ² / s)) at 40 ° C. The base oil is prepared by adjusting the kinematic viscosity at 100 ° C. to 3.6 to 4.1 mm ² / s, and mineral oil base oil, synthetic base oil, and mixtures thereof can be used.

  As a mineral oil base oil, a lubricating oil fraction obtained by subjecting crude oil to atmospheric distillation and vacuum distillation is subjected to solvent removal, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining. In addition, paraffinic and naphthenic mineral oil base oils, normal paraffins, isoparaffins, and the like, which are refined alone or in appropriate combination of two or more purification treatments such as sulfuric acid washing and clay treatment, can be mentioned. These base oils may be used alone or in combination of two or more at any ratio.

Preferred mineral oil base oils include the following base oils.
(1) Distilled oil obtained by atmospheric distillation of paraffin-based crude oil and / or mixed-base crude oil;
(2) Vacuum distillation distillate (WVGO) of paraffinic base oil and / or mixed base oil of atmospheric distillation residue;
(3) Fischer-Tropsch wax produced by a wax and / or GTL process obtained by a lubricant dewaxing step;
(4) Mild hydrocracking treatment oil (MHC) of one or more mixed oils selected from (1) to (3);
(5) A mixed oil of two or more oils selected from (1) to (4);
(6) Dried oil (DAO) of (1), (2), (3), (4) or (5);
(7) Mild hydrocracking treatment oil (MHC) of (6);
(8) A mixed oil of two or more kinds of oils selected from (1) to (7) is used as a raw oil, and this raw oil and / or a lubricating oil fraction recovered from this raw oil Lubricating oil obtained by refining by the refining method and collecting the lubricating oil fraction

  The normal refining method here is not particularly limited, and a refining method used in the production of the lubricating base oil can be arbitrarily employed. Examples of conventional purification methods include (a) hydrorefining such as hydrocracking and hydrofinishing, (b) solvent purification such as furfural solvent extraction, and (c) dewaxing such as solvent dewaxing and catalytic dewaxing. And (d) white clay refining with acid clay and activated clay, and (e) chemical (acid or alkali) purification such as sulfuric acid washing and caustic soda washing. In the present invention, one or more of these can be used in any combination and in any order.

The mineral oil base oil used in the present invention is particularly preferably a base oil obtained by further subjecting the base oil selected from the above (1) to (8) to the following treatment.
That is, the base oil selected from the above (1) to (8) is used as it is or the lubricating oil fraction recovered from this base oil is hydrocracked or wax isomerized, and the product is used as it is or from now on. Collect the fraction, and then perform dewaxing treatment such as solvent dewaxing or contact dewaxing, and then solvent refining treatment, or after solvent refining treatment, dewaxing such as solvent dewaxing or contact dewaxing Hydrocracked mineral oil and / or wax isomerized isoparaffinic base oil produced by treatment is preferably used.

  Synthetic lubricating base oils include poly α-olefins or hydrides thereof, isobutene oligomers or hydrides thereof, isoparaffins, alkylbenzenes, alkylnaphthalenes, diesters (for example, ditridecyl glutarate, di-2-ethylhexyl adipate, Diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, etc.), polyol esters (eg, trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, etc.), Polyoxyalkylene glycol, dialkyl diphenyl ether, polyphenyl ether and the like can be mentioned.

  Preferable synthetic lubricating base oils include poly α-olefins. The poly α-olefin is typically an α-olefin oligomer or co-oligomer having 2 to 32 carbon atoms, preferably 6 to 16 (eg, 1-octene oligomer, 1-decene oligomer, ethylene-propylene co-oligomer). And hydrides thereof.

Kinematic viscosity at 100 ° C. of the lubricating base oil of the component (A) in the present invention is 3.6~4.1mm ² / s, preferably 3.8 mm ² / s or more, or less 4.0 mm ² / s is there. By setting the kinematic viscosity at 100 ° C. to 4.1 mm ² / s or less, it is possible to obtain a lubricating oil composition having a smaller frictional resistance at a lubricated portion because the fluid resistance is reduced. In addition, by setting the kinematic viscosity at 100 ° C. to 3.6 mm ² / s or more, the oil film formation is sufficient, the lubricity is excellent, and the lubricating oil composition has a smaller base oil evaporation loss under high temperature conditions. Can be obtained.

One of the effects of improving fuel economy in the present invention is achieved by reducing the traction coefficient. One major factor affecting this traction coefficient is the saturated cyclic component of the base oil. The more this is, the higher the traction coefficient tends to be. Another major factor is base oil viscosity.
A lower base oil viscosity is more advantageous for fuel saving, but if it is too low, various adverse effects appear, so it is desirable that the base oil viscosity be within the range described above. However, as described above, since the traction coefficient is greatly influenced by the viscosity of the base oil and the amount of the saturated cyclic component of the base oil, the lubricating base oil in the present invention lowers the traction coefficient. It is necessary that the product (EC × V40) of the weight percent of the saturated cyclic component (EC (wt%)) and the kinematic viscosity (V40 (mm ² / s)) at 40 ° C. is 500 or less. Preferably it is 470 or less, More preferably, it is 450 or less, Especially preferably, it is 400 or less, Most preferably, it is 350 or less.
Here, the saturated cyclic component is a value measured according to the test method of ASTM D2786, and is converted so that the unit is weight percent.

  Further, the viscosity index of the lubricating base oil in the present invention is not particularly limited, but the viscosity index is preferably 100 or more, more preferably 110 or more, particularly preferably 130 or more, and most preferably 135 or more. Moreover, it is preferable that it is 160 or less. By setting the viscosity index to 100 or more, it is possible to obtain a composition exhibiting good viscosity characteristics from low temperature to high temperature, and to obtain a low traction coefficient. On the other hand, if the viscosity index exceeds 160, the viscosity characteristics at low temperatures may be deteriorated, which is not preferable.

  Further, the sulfur content of the lubricating base oil in the present invention is not particularly limited, but is preferably 100 ppm by mass or less, more preferably 10 ppm by mass or less, and particularly preferably 1 ppm by mass or less. By reducing the sulfur content of the component (A), it is possible to obtain a composition that is more excellent in oxidative stability of the composition.

As the (A) lubricating base oil in the present invention, (A1) a base oil alone obtained by hydrocracking and dewaxing a feedstock containing 50% by mass or more of wax, or (A1) a base oil and (A2) hydrogenated Particularly preferred is a mixture of base oil that has been cracked and contact-dewaxed.
In addition, as the base oil obtained by hydrocracking and dewaxing a raw material oil containing 50% by mass or more of (A1) wax, the wax content of the raw material oil is preferably 60% by mass or more, particularly preferably 80% by mass or more.

The mixing ratio of the (A1) base oil and the (A2) base oil is preferably 20% by mass or more, more preferably 40% by mass or more, particularly preferably 70% by mass or more of the (A1) base oil based on the total amount of the base oil. It is desirable to use 90% by mass or more most preferably. (A1) By mixing the base oil ratio of 20% by mass or more, the viscosity index of the composition can be made 175 or more, and the traction coefficient can be reduced, so that excellent fuel economy can be exhibited.
When (A1) base oil is compared with (A2) base oil in the structure of the molecules constituting each base oil, the length of the methylene chain is longer in (A1) base oil when comparing branches with the same number of carbon atoms. This is because the viscosity index is high and the traction coefficient is low. This feature is superior to the aforementioned poly α-olefin synthetic oil.

The (A) lubricating base oil in the lubricating oil composition of the present invention is a lubricating base oil whose kinematic viscosity at 100 ° C. is adjusted to 3.6 to 4.1 mm ² / s, preferably (Aa 1 type or 2 types or more selected from (Ab) or (Ab).
(Aa) Mineral oil having a kinematic viscosity at 100 ° C. of less than 1.5 to 3.5 mm ² / s, preferably 1.9 to 3.2 mm ² / s, more preferably 2.2 to 2.9 mm ² / s. Base oil (Ab) Mineral oil base oil having a kinematic viscosity at 100 ° C. of less than 3.5 to 7 mm ² / s, preferably 3.6 to 4.5 mm ² / s
Of course, these (Aa) base oil and (Ab) base oil are either (A1) base oil or (A2) base oil, respectively.

  By using a mixture of base oils having different viscosities, the viscosity index of the composition can be increased while maintaining the same base oil viscosity, so that the fuel economy of the composition can be improved.

The lubricating oil composition of the present invention contains a phosphorus compound as the component (B).
The phosphorus compound is not particularly limited as long as it contains phosphorus in the molecule. For example, phosphate monoesters, phosphate diesters and phosphate triesters having a hydrocarbon group having 1 to 30 carbon atoms. , Phosphorous acid monoesters, phosphorous acid diesters, phosphorous acid triesters, thiophosphoric acid monoesters, thiophosphoric acid diesters, thiophosphoric acid triesters, thiophosphorous acid monoesters, thiophosphorous acid Acid diesters, thiophosphite triesters, salts of these esters with amines or alkanolamines, metal salts such as zinc salts, and the like can be used.

  Specific examples of the hydrocarbon group having 1 to 30 carbon atoms include an alkyl group, a cycloalkyl group, an alkenyl group, an alkyl-substituted cycloalkyl group, an aryl group, an alkyl-substituted aryl group, and an arylalkyl group. One type or two or more types can be arbitrarily blended. The hydrocarbon group may be a hydrocarbon group containing sulfur in the main chain.

In the present invention, among the phosphorus compounds, phosphites or phosphates having an alkyl group having 4 to 20 carbon atoms or an (alkyl) aryl group having 6 to 12 carbon atoms are preferable.
Moreover, the 1 type, or 2 or more types of mixture chosen from the phosphite which has a C4-C20 alkyl group, and the phosphite which has a C6-C12 (alkyl) aryl group is more preferable.
Furthermore, phosphites having a C6-C7 (alkyl) aryl group such as phenyl phosphite and / or phosphites having a C4-C8 alkyl group are more preferred. Of these, dibutyl phosphite is most preferred.
The alkyl group may be linear, but is more preferably branched. This is because the friction coefficient between metals is higher when the number of carbon atoms is smaller and when it is branched.

  The phosphorus compound as the component (B) in the present invention is preferably (B-1) a phosphorus compound represented by the following general formula (1).

Here, in Formula (1), X ¹ , X ² and X ³ each independently represent an oxygen atom or a sulfur atom, and R ²⁰ , R ²¹ and R ²² each independently represent a hydrogen atom, a carbon number of 1 to 30 hydrocarbon group or a C3-C30 hydrocarbon group containing at least one sulfur is shown.

In the formula (1), it is preferable that X ¹ , X ² and X ³ are all oxygen atoms. Moreover, it is preferable that at least one of R ²⁰ , R ²¹ and R ²² is a hydrogen atom. Furthermore, it is preferable that at least one of R ²⁰ , R ²¹ and R ²² is a hydrogen atom, and the other one or both is a linear hydrocarbon group containing sulfur in the main chain. In particular, it is preferable that one of R ²⁰ , R ^21, and R ²² is a hydrogen atom, and the remaining both are linear hydrocarbon groups containing sulfur in the main chain. Thereby, the wear resistance and the friction coefficient between metals can be improved.
In addition, it is preferable that the linear hydrocarbon group containing sulfur in the main chain has a different carbon number.

Here, the linear hydrocarbon group containing sulfur in the main chain represents a group represented by the following formula.
_{- (CH 2) n -S-} C m H 2m + 1

When one of R ²⁰ , R ^21, and R ²² is a hydrogen atom and the remaining both are linear hydrocarbon groups containing sulfur in the main chain, oxygen bonded to phosphorus and the main chain of the hydrocarbon group The number n of carbon atoms of the alkylene group between the contained sulfur is preferably 4 or less, and more preferably 2 or less. Further, at least one of the alkyl groups bonded to sulfur in the main chain of the hydrocarbon group is preferably 8 or more, and more preferably 10 or more. The other is preferably 4 or less, and more preferably 2 or less. The alkyl group having 4 or less carbon atoms is most preferably substituted at the terminal hydrogen with a hydroxyl group. This can further improve the wear resistance and the friction coefficient between metals.

When all of R ²⁰ , R ²¹ and R ²² are linear hydrocarbon groups containing sulfur in the main chain, an alkylene group between oxygen bonded to phosphorus and sulfur contained in the main chain of the hydrocarbon group The carbon number n of each is preferably 4 or less, more preferably 2 or less. Further, the carbon number m of the alkyl group bonded to sulfur in the main chain of the hydrocarbon group is preferably 8 or more, and more preferably 10 or more. This can further improve the wear resistance and the friction coefficient between metals.

The phosphorus compound of the component (B) in the lubricating oil composition of the present invention may be further used by mixing (B-2) a phosphorus compound represented by the following general formula (2).

In formula (2), R ²³ , R ²⁴ and R ²⁵ each independently represent a hydrogen atom or a hydrocarbon group having 3 to 30 carbon atoms.

  When the component (B-1) and the component (B-2) are mixed and used, the ratio of the component (B-2) and the component (B-1) on the basis of the amount of phosphorus element (B-2) / (B -1) is preferably 0 to 2, and more preferably 0 to 0.5. This can further improve wear resistance and metal fatigue durability.

  The content of the phosphorus compound as the component (B) in the lubricating oil composition of the present invention is 0.01% by mass as the phosphorus element amount, based on the total amount of the lubricating oil composition, and preferably is 0.00%. On the other hand, the upper limit is 0.03% by mass, preferably 0.025% by mass. By setting the content of the component (B) within the above range, it is possible to obtain a lubricating oil composition having excellent torque transmission force and transmission characteristics and excellent anti-shudder performance.

  The lubricating oil composition of the present invention contains calcium salicylate and / or calcium sulfonate as the component (C).

  The calcium salicylate is not particularly limited in its structure, but a calcium salt of salicylic acid having 1 to 2 alkyl groups having 1 to 30 carbon atoms is used.

  In the present invention, calcium salicylate has a monoalkyl salicylic acid calcium salt composition ratio of 85 to 100 mol%, a dialkyl salicylic acid calcium salt composition ratio of 0 to 15 mol%, and a 3-alkyl salicylic acid calcium salt composition ratio of 40 to Alkyl salicylic acid calcium salt and / or its (over) basic salt, which is 100 mol%, is preferred in that it can further improve the anti-shudder lifetime.

  The alkyl group in the alkyl salicylic acid calcium salt has 10 to 40 carbon atoms, preferably 10 to 19 carbon atoms or 20 to 30 carbon atoms, more preferably an alkyl group having 14 to 18 carbon atoms or 20 to 26 carbon atoms, Particularly preferred is an alkyl group having 14 to 18 carbon atoms. These alkyl groups may be linear or branched, and may be a primary alkyl group or a secondary alkyl group.

  As calcium salicylates, basic salts obtained by heating an alkali metal salt or a neutral salt of calcium and an excess calcium salt in the presence of water, carbon dioxide, boric acid or borate salts. Also included are overbased salts obtained by reacting the neutral salt with a base such as calcium hydroxide in the presence.

In the lubricating oil composition of the present invention, calcium sulfonate can also be used as the component (C), and the structure thereof can be used without any particular limitation. For example, the molecular weight is 100 to 1500, preferably 200. A calcium salt of alkyl aromatic sulfonic acid obtained by sulfonating ˜700 alkyl aromatic compounds is preferably used.

In addition, as calcium sulfonate, the above alkyl aromatic sulfonic acid is directly reacted with an oxide or hydroxide of calcium, or once converted to an alkali metal salt such as sodium salt or potassium salt and then replaced with calcium salt. Neutral alkaline earth metal sulfonate obtained by the above, or basic calcium obtained by heating the above neutral calcium sulfonate and excess calcium salt or calcium base (hydroxide or oxide) in the presence of water Carbonate overbased calcium sulfonate, borate overbased calcium sulfonate obtained by reacting the neutral metal sulfonate with a calcium base in the presence of sulfonate, carbon dioxide and / or boric acid or borate Is also included.
In the present invention, the above neutral calcium sulfonate, basic calcium sulfonate, overbased calcium sulfonate, and a mixture thereof can be used.

  The base number of the calcium salicylate and / or calcium sulfonate as the component (C) used in the present invention is arbitrary and is usually 0 to 500 mgKOH / g, but the base number is 100 to 450 mgKOH / g, preferably 200-400 mg KOH / g. In addition, the base number here means the base number by the perchloric acid method measured based on JIS K2501.

  In the lubricating oil composition of the present invention, the content of the component (C) is 0.03 to 0.05% by mass as the amount of calcium element based on the total amount of the composition. Preferably it is 0.035 mass% or more, More preferably, it is 0.04 mass% or more. Moreover, Preferably it is 0.045 mass% or less. By setting the content of the component (C) within the above range, it is possible to obtain a lubricating oil composition having excellent torque transmission force and transmission characteristics and excellent anti-shudder performance.

  In the lubricating oil composition of the present invention, the ratio (P / Ca) of the phosphorus element mass content of the component (B) and the calcium mass content of the component (C) in the lubricating oil composition is 0.3-0. 0.7, preferably 0.4 to 0.6, particularly preferably 0.45 to 0.55. By setting the content of the component (C) within the above range, it is possible to obtain a lubricating oil composition having excellent torque transmission force and transmission characteristics and excellent anti-shudder performance.

  The lubricating oil composition of the present invention contains a boron-modified ashless dispersant as the component (D).

  In the present invention, as the ashless dispersant, any ashless dispersant used for lubricating oils can be used. For example, a linear or branched alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule. Examples thereof include at least one nitrogen-containing compound or derivative thereof, or a modified product of alkenyl succinimide. One type or two or more types arbitrarily selected from these can be blended.

  The alkyl group or alkenyl group has 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms. When the carbon number of the alkyl group or alkenyl group is less than 40, the solubility of the compound in the lubricating base oil decreases, whereas when the carbon number of the alkyl group or alkenyl group exceeds 400, the lubricating oil composition Since low temperature fluidity deteriorates, it is not preferable respectively. The alkyl group or alkenyl group may be linear or branched, but specifically, preferred are derived from olefin oligomers such as propylene, 1-butene and isobutylene, and co-oligomers of ethylene and propylene. And a branched alkyl group and a branched alkenyl group.

Specific examples of the ashless dispersant include, for example, the following compounds, and one or more compounds selected from these can be used.
(I) Succinimide having at least one alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule, or a derivative thereof (II) At least one alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule Benzylamine or derivative thereof (III) Polyamine or derivative thereof having at least one alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule.

  More specifically, examples of (I) succinimide include compounds represented by the following general formula (3) or (4).

In the general formula (3), R ¹ represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350, and a represents an integer of 1 to 5, preferably 2 to 4.

In the general formula (4), R ² and R ³ each independently represent an alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms, more preferably a polybutenyl group, and b is 0 to 4, Preferably the integer of 1-3 is shown.

  The succinimide is represented by the general formula (3) in which succinic anhydride is added to one end of the polyamine, and the general formula in which succinic anhydride is added to both ends of the polyamine. Although the so-called bis-type succinimide represented by (4) is included, the lubricating oil composition of the present invention may include only one of them or a mixture thereof. Also good.

  The method for producing the succinimide is not particularly limited. For example, an alkyl or alkenyl succinic acid obtained by reacting a compound having an alkyl group or alkenyl group having 40 to 400 carbon atoms with maleic anhydride at 100 to 200 ° C. is a polyamine. It can obtain by making it react. Specific examples of polyamines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine.

More specifically, examples of (II) benzylamine include compounds represented by the following general formula (5).

In the general formula (5), R ⁴ represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350, and c represents an integer of 1 to 5, preferably 2 to 4.

  Although the manufacturing method of the said benzylamine is not limited at all, For example, after making polyolefin, such as a propylene oligomer, polybutene, and an ethylene-alpha-olefin copolymer, react with phenol to make alkylphenol, this is made into formaldehyde and It can be obtained by reacting polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine by Mannich reaction.

More specifically, examples of the (III) polyamine include compounds represented by the following general formula (6).
R ⁵ —NH— (CH ₂ CH ₂ NH) _d —H (6)
In the general formula (6), R ⁵ represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350, and d represents an integer of 1 to 5, preferably 2 to 4.

  The method for producing the polyamine is not limited in any way. For example, after chlorinating a polyolefin such as propylene oligomer, polybutene, and ethylene-α-olefin copolymer, ammonia, ethylenediamine, diethylenetriamine, and triethylene are added thereto. It can be obtained by reacting polyamines such as tetramine, tetraethylenepentamine, and pentaethylenehexamine.

  In the present invention, a so-called boron-modified ashless dispersant in which boric acid is allowed to act on the above ashless dispersant to neutralize part or all of the remaining amino group and / or imino group is used as the component (D). To do. This boron-modified ashless dispersant is excellent in heat resistance and oxidation resistance, and is particularly effective for improving oxidation stability and corrosion resistance even in the continuously variable transmission lubricating oil composition of the present invention.

  In general, the boron-modified compound is produced by allowing a boron compound to act on the above-described ashless dispersant to neutralize part or all of the remaining amino group and / or imino group. For example, as a method for producing boric acid-modified succinimide, JP-B-42-8013, JP-B-42-8014, JP-A-51-52381, JP-A-51-130408, etc. The disclosed method etc. are mentioned. Specifically, boron compounds such as boric acid, boric acid esters, or boric acid salts are added to polyamines and polyalkenyl succinic acid (anhydrides) to organic solvents such as alcohols, hexane and xylene, light lubricating base oils, and the like. It can be obtained by mixing and heat-treating under appropriate conditions.

  The boron content of the boron-containing ashless dispersant such as the boron-containing succinimide is not particularly limited, and is usually 0.1 to 3% by mass, preferably 0.3% by mass or more, and preferably It is 2 mass% or less, More preferably, it is 1.7 mass% or less, Most preferably, it is 1.5 mass% or less. As the boron-containing ashless dispersant, it is preferable to use a boron-containing succinimide having a boron content within this range, and it is particularly preferable to use a boron-containing bissuccinimide. In addition, when boron content exceeds 3 mass%, there is a concern about stability.

  Further, the boron / nitrogen mass ratio (B / N ratio) of the boron-containing ashless dispersant such as boron-containing succinimide is not particularly limited, but is usually 0.05 to 5, preferably 0.2 or more. Also, it is preferably 2 or less, more preferably 1.5 or less, still more preferably 1.0 or less, and particularly preferably 0.9 or less. As the boron-containing ashless dispersant, it is preferable to use a boron-containing succinimide having a B / N ratio within this range, and it is particularly preferable to use a boron-containing bissuccinimide. When the B / N ratio exceeds 5, there is a concern about stability.

In the lubricating oil composition of the present invention, the content of the component (D) boron-modified ashless dispersant is 0.001% by mass or more, preferably 0.003% by mass or more, based on the total amount of the composition, as the amount of boron element. Moreover, it is 0.008 mass% or less, Preferably it is 0.006 mass% or less.
If the boron content in the composition exceeds 0.008% by mass, the friction characteristics of the wet friction clutch deteriorate, which is not preferable. If it is less than 0.001% by mass, as described above, no effect is observed in the improvement of oxidation stability and corrosion resistance, which are one of the performances of the lubricating oil composition for continuously variable transmissions.

The lubricating oil composition of the present invention contains a friction modifier as the component (E).
The friction modifier is preferably a fatty acid ester friction modifier and / or a fatty acid amide friction modifier.
The fatty acid used as a raw material for the fatty acid ester compound and fatty acid amide compound blended as a friction modifier preferably has a straight chain structure, and the hydrocarbon group may be an alkyl group or an alkenyl group. The carbon number is 10 to 30, preferably 12 or more, and more preferably 16 or more. Moreover, 26 or less is preferable and 24 or less is more preferable. When the number of carbon atoms is less than 10, the effect as a friction modifier is poor, and when the number of carbon atoms exceeds 30, the low-temperature viscosity characteristics as the composition may be deteriorated.

  Moreover, as alcohol used as the raw material of the fatty acid ester type compound mix | blended as a friction modifier, a monohydric alcohol or a polyhydric alcohol may be sufficient, but a polyhydric alcohol is preferable. As the polyhydric alcohol, those having 2 to 10 valences, preferably 2 to 6 valences are usually used. Specific examples of the divalent to 10-valent polyhydric alcohol include, for example, ethylene glycol, diethylene glycol, polyethylene glycol (3 to 15 mer of ethylene glycol), propylene glycol, dipropylene glycol, and polypropylene glycol (3 to 3 of propylene glycol). 15-mer), 1,3-propanediol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,2-propanediol, 2-methyl-1, Dihydric alcohols such as 3-propanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, neopentylglycol, glycerin, polyglycerin (glycerin 2 ~ Octamer, eg diglycerin, trig Serine, tetraglycerin, etc.), trimethylol alkanes (trimethylol ethane, trimethylol propane, trimethylol butane, etc.) and their 2-to 8-mer, pentaerythritol and their 2-to 4-mer, 1,2,4- Butanetriol, 1,3,5-pentanetriol, 1,2,6-hexanetriol, 1,2,3,4-butanetetrol, sorbitol, sorbitan, sorbitol glycerin condensate, adonitol, arabitol, xylitol, mannitol, etc. Polyhydric alcohols, xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, saccharides such as isomaltose, trehalose, sucrose, and mixtures thereof And the like. Among these polyhydric alcohols, ethylene glycol, diethylene glycol, polyethylene glycol (ethylene glycol 3-10 mer), propylene glycol, dipropylene glycol, polypropylene glycol (propylene glycol 3-10 mer), 1,3- Propanediol, 2-methyl-1,2-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, glycerin, diglycerin, triglycerin, trimethylolalkane (trimethylolethane, trimethylolpropane, trimethylol Methylol butane and the like, and dimers and tetramers thereof, pentaerythritol, dipentaerythritol, 1,2,4-butanetriol, 1,3,5-pentanetriol, 1,2,6-hexanetrio Le, 1,2,3,4 butane tetrol, sorbitol, sorbitan, sorbitol glycerin condensate, adonitol, arabitol, xylitol, divalent to hexavalent polyhydric alcohols, and mixtures thereof, such as mannitol and the like are preferable. Furthermore, ethylene glycol, propylene glycol, neopentyl glycol, glycerin, trimethylol ethane, trimethylol propane, and a mixture thereof are more preferable. Among these, glycerin is particularly preferable.

  Moreover, as an amine used as the raw material of the fatty acid amide compound compounded as a friction modifier, either ammonia, primary amine, or secondary amine may be used, but ammonia or primary amine is preferable. Specific examples of the primary amine include monoalkylamines, monoalkanolamines, aromatic amines, and diamines typified by ethylenediamine. Among these, ammonia is particularly preferable.

  Specific examples of the (E) fatty acid ester friction modifier used in the present invention include, for example, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, eicosanoic acid, behen. Examples include esters obtained by reacting fatty acids selected from acids, lignoceric acids or mixtures thereof with alcohols selected from ethylene glycol, propylene glycol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane or mixtures thereof. be able to. The ester structure may be a complete ester in which all the hydroxyl groups in the polyhydric alcohol are esterified, or a partial ester in which a part of the hydroxyl groups are not esterified and remain as hydroxyl groups. Of these, the partial esters of fatty acids having 16 to 20 carbon atoms and glycerin described above are preferred.

  Specific examples of the (E) fatty acid amide friction modifier used in the present invention include, for example, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, eicosanoic acid, behen. Mention may be made of amides obtained by reacting fatty acids selected from acids, lignoceric acids or mixtures thereof with ammonia, methylamine, ethylamine, ethanolamine, aniline, ethylenediamine or mixtures thereof. The amide structure may be any of primary amide, secondary amide, and tertiary amide, but primary amide or secondary amide is preferred. Of these, the primary amides of fatty acids having 16 to 20 carbon atoms and ammonia are preferable.

  In the lubricating oil composition of the present invention, by using a fatty acid ester compound and / or a fatty acid amide friction modifier as a friction modifier, it is possible to ensure anti-shudder properties without reducing the friction coefficient between metals. it can.

  The content of the component (E) is 0.01 to 2% by mass, preferably 0.05% by mass or more, and preferably 1.0% by mass or less, more preferably 0.5% by mass based on the total amount of the composition. % Or less, more preferably 0.2% by mass or less. If it is less than 0.01% by mass, the effect of the friction modifier is not exhibited, and if it exceeds 2% by mass, there is a concern about solubility at low temperatures.

The lubricating oil composition of the present invention preferably contains a viscosity index improver as the component (F).
The viscosity index improver used in the lubricating oil composition of the present invention is a poly (meth) acrylate-based additive substantially containing a structural unit derived from a monomer represented by the following general formula (7). Is preferred.

In the general formula (7), R ¹ is hydrogen or a methyl group, preferably a methyl group, and R ² is a hydrocarbon group having 1 to 30 carbon atoms.
Specific examples of the hydrocarbon group having 1 to 30 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, Chain or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched Decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear Or a branched hexadecyl group, a linear or branched heptadecyl group, a linear or branched octadecyl group, a linear or branched nonadecyl group, a linear or branched icosyl group, a linear or branched heicosyl group Group, straight chain or branched docosyl group, straight chain The branched tricosyl group, and an alkyl group having 1 to 30 carbon atoms, such as straight-chain or branched tetracosyl groups.

The poly (meth) acrylate-based additive of the component (F) in the present invention is represented by the following general formulas (8) and (9) in addition to the structural unit derived from the monomer represented by the general formula (7). Structural units derived from the monomers represented can also be included.

In the general formula (8), R ³ is hydrogen or a methyl group, preferably a methyl group, R ⁴ is an alkylene group having 1 to 30 carbon atoms, E ¹ is ¹ to 2 nitrogen atoms, and 0 to 2 oxygen atoms. An amine residue or a heterocyclic residue to be contained is shown, and a represents an integer of 0 or 1.

In the general formula (9), R ⁵ is hydrogen or a methyl group. E ² represents an amine residue or a heterocyclic residue containing 1 to 2 nitrogen atoms and 0 to 2 oxygen atoms.

Specific examples of the group represented by E ¹ and E ² include a dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, an anilino group, a toluidino group, a xylidino group, an acetylamino group, and a benzoylamino group. Morpholino group, pyrrolyl group, pyrrolino group, pyridyl group, methylpyridyl group, pyrrolidinyl group, piperidinyl group, quinonyl group, pyrrolidonyl group, pyrrolidono group, imidazolino group, pyrazino group and the like.

  Specific examples of this include dimethylaminomethyl methacrylate, diethylaminomethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-methyl-5-vinylpyridine, morpholinomethyl methacrylate, morpholinoethyl methacrylate, N-vinylpyrrolidone. And a mixture thereof.

Specifically, the viscosity index improver (component (F)) includes the monomer of general formula (7) consisting of the following (Fa) to (Fd), and general formula (8) and / or Or it is a copolymer with the polar group containing monomer of (Fe) represented by (9).
(Fa) R ² is an alkyl group having 1 to 4 carbon atoms (meth) acrylate (Fb) R ² is an alkyl group having 5 to 10 carbon atoms (meth) acrylate (Fc) R ² is 12 to 12 carbon atoms (Meth) acrylate (Fe) polar group-containing monomer wherein 18 (meth) acrylate (Fd) R ² is an alkyl group having 20 or more carbon atoms

In the present invention, the constituent ratio of the monomer in the component (F) is preferably as follows on the basis of the total amount of monomers constituting the poly (meth) acrylate.
(Fa) component: preferably 10 to 60% by mass, more preferably 20 to 50% by mass,
Component (Fb): preferably 0 to 50% by mass, more preferably 0 to 20% by mass
(Fc) component: preferably 10 to 60% by mass, more preferably 20 to 40% by mass,
(Fd) component: preferably 1 to 20% by mass, more preferably 5 to 10% by mass,
(Fe) component: preferably 0 to 20% by mass, more preferably 0 to 10% by mass, particularly preferably 0% by mass

  By setting it as this composition, the low-temperature viscosity characteristic of a composition and the fatigue life extension effect can be made compatible.

  The method for producing the poly (meth) acrylate is arbitrary, but for example, it is easily obtained by radical solution polymerization of a mixture of monomers (Fa) to (Fe) in the presence of a polymerization initiator such as benzoyl peroxide. be able to.

  The weight average molecular weight of the (F) component poly (meth) acrylate-based additive is 60,000 or less, preferably 50,000 or less, more preferably 40,000 or less, and 5,000 or more, preferably 10,000. As mentioned above, More preferably, it is 20,000 or more. If it exceeds 60,000, the shear stability is too low, and the required viscosity as the lubricating oil composition cannot be maintained. On the other hand, if it is less than 5,000, the effect of improving the viscosity index is reduced, so that the fuel efficiency is deteriorated.

The blending amount of the poly (meth) acrylate additive of the component (F) in the lubricating oil composition of the present invention is such that the kinematic viscosity at 100 ° C. of the lubricating oil composition is 5.2 to 5.6 mm ² / s, and It is added so that the viscosity index of the lubricating oil composition is 165 or more.
More specifically, the blending amount is 15% by mass or less, preferably 10% by mass or less, more preferably 6% by mass or less, and 2% by mass or more, preferably 3% by mass based on the total amount of the lubricating oil composition. As mentioned above, More preferably, it is 4 mass% or more. If it exceeds 15% by mass, the viscosity drop due to shear becomes too large, and if it is less than 2% by mass, a sufficient composition viscosity cannot be ensured.

The lubricating oil composition of the present invention has a kinematic viscosity at 100 ° C. of 5.2 to 5.6 mm ² / s and a viscosity index of 165 or more.
When the kinematic viscosity at 100 ° C. is less than 5.2, there is a concern that the reliability of the apparatus may be reduced due to the decrease in extreme pressure property or the fatigue life of the bearing, and when the viscosity exceeds 5.6 mm ² / s, or the viscosity When the index is less than 165, the fuel saving effect is reduced.

  The lubricating oil composition of the present invention preferably has a viscosity reduction rate at 100 ° C. after 20 hours of a sonic shear test of 8% or less. The sonic shear test here is based on the test method specified in JASO M347.

As described above, the lubricating oil composition of the present invention is also used as a medium for a hydraulic control device. When the viscosity decreases, sufficient oil pressure is generated due to oil leakage from an oil pump or a control valve. Inconveniences such as inability to occur. For this reason, it is necessary for the lubricating oil used to maintain the necessary viscosity until the end of the life of the machine.
For this reason, it is necessary to maintain a sufficient viscosity even when a shearing force is repeatedly applied to the lubricating oil composition of the present invention. The fact that the viscosity reduction rate at 100 ° C. after 20 hours of the sonic shear test of the lubricating oil composition of the present invention is 8% or less is a value that guarantees this.
On the other hand, by reducing the addition amount of the viscosity index improver, the viscosity reduction rate can be reduced. On the other hand, since the viscosity index is small, the fuel saving effect is small. Therefore, the range of the viscosity reduction rate in the lubricating oil composition of the present invention is preferably 2% or more and 8% or less, more preferably 3.5% or more and 7% or less.

  The lubricating oil composition of the present invention preferably has a traction coefficient of 0.02 or less at 40 ° C., an average speed of 3.0 m / s, a slip ratio of 10%, and a surface pressure of 0.4 GPa.

  This traction coefficient is measured with a steel ball-disk device. This was done by rotating a disk with a radius of 13 cm at 286.7 rpm, applying a 20 N load to a ball with a radius of 1.27 cm at a radius of 10 cm, an average speed of 3.0 m / s at 40 ° C., a slip rate of 10%, and surface pressure This is calculated from the rotational torque applied to the ball at 0.4 GPa.

  This condition does not reach the so-called perfect elastohydrodynamic lubrication condition, and is still in the middle region between the hydrodynamic lubrication condition and the elastohydrodynamic lubrication condition. In the conventional technology, the traction coefficient is measured at a high surface pressure, specifically, a surface pressure exceeding 1 GPa, and the ease of forming an oil film under a high surface pressure condition of the lubricating oil composition, that is, the traction coefficient is high. It was judged that the oil film was more easily formed as the composition, and the lubricity under severe conditions was better.

However, the measurement condition of the traction coefficient in the present invention is a measurement value under an intermediate surface pressure condition of 0.4 GPa as described above, and the traction coefficient is out of the lubrication region of the machine except for lubrication with a ball bearing or a roller bearing. It may be considered as a representative condition of a portion where the coefficient is a resistance related to lubrication. Therefore, reducing the traction coefficient under this condition reduces the resistance applied to the traction coefficient under the lubrication conditions of the machine. That is, in the present invention, the fuel efficiency can be further ensured by setting the traction coefficient to 0.02 or less at an average speed of 3.0 m / s at 40 ° C., a slip rate of 10%, and a surface pressure of 0.4 GPa. is there.

  The traction coefficient under these conditions is preferably 0.02 or less. The lower the better, the better. However, as described above, it is preferably 0.005 or more in order to ensure lubricity of ball bearings, roller bearings and the like under higher surface pressure.

  Further, the lubricating oil composition of the present invention is required to have a high coefficient of friction between metals as a lubricating oil composition for a continuously variable transmission. This is because the higher the coefficient of friction between the belt and pulley of the metal belt type continuously variable transmission, the same torque can be transmitted even if the belt pressing pressure is low, that is, high torque can be transmitted with low hydraulic pressure. is there.

The friction characteristics between the belt and pulley of the metal belt type continuously variable transmission are evaluated using a Falex Block-on-Ring Test Machine. Specific conditions are as follows.
(Test conditions)
Ring: Falex S-10 Test Ring (EAE 4620Steel)
Block: Falex H-60 Test Block
Oil temperature: 80 ° C
Load load: 445N
Sliding speed: 0.1 m / s

  Under the above conditions, the coefficient of friction between metals is preferably 0.115 or more. More preferably, it is 0.118 or more, Most preferably, it is 0.12 or more. Moreover, it is 0.14 or less. If it is less than 0.115, the fuel saving performance targeted by the present invention cannot be exhibited, and if it exceeds 0.14, it becomes difficult to satisfy the anti-shudder property. Further, since the friction of the bearing portion is increased, there is a concern that fuel efficiency is reduced.

The friction characteristics of the transmission clutch of the metal belt type continuously variable transmission are SAE No. It is evaluated using two testing machines. According to JASO M348: 2002, in the evaluation using SD-1777X as a friction plate, the coefficient of static friction (μ _t ) is 0.13 or more, 0.16 or less, μ ₀ / mu _d is 0.9 or more and 1.05 or less. If the coefficient of static friction is less than 0.13, there is a concern about the slippage of the speed change clutch. Further, if μ ₀ / μ _d exceeds 1.05, there is a concern about the occurrence of shock at the time of shifting, and if it is less than 0.9, it is difficult to ensure a static friction coefficient.

  The anti-shudder property in the lock-up clutch of the metal belt type continuously variable transmission is evaluated based on JASO M349: 2010 using a low speed slip tester (LVFA). In this evaluation, dμ / dv at 0.3 m / s is preferably a positive gradient. When dμ / dv has a negative slope, there is a concern about the generation of shudder.

  For the purpose of further improving the performance of the lubricating oil composition of the present invention or for imparting the necessary performance to the lubricating oil composition, a viscosity index improver other than the above-described additives, if necessary. , Extreme pressure agent, dispersant, metal detergent, antioxidant, corrosion inhibitor, rust inhibitor, demulsifier, metal deactivator, pour point depressant, seal swelling agent, antifoaming agent, colorant, etc. These various additives may be blended singly or in combination.

As the viscosity index improver, in addition to the poly (meth) acrylate of component (F) described above, non-dispersed or dispersed ethylene-α-olefin copolymer or hydride thereof, polyisobutylene or hydride thereof, styrene- Diene hydrogenated copolymer, styrene-maleic anhydride copolymer, polyalkylstyrene and (meth) acrylate monomer represented by the general formula (7) and ethylene / propylene / styrene / maleic anhydride A viscosity index improver such as a copolymer with a saturated monomer can be further used.
When blending a viscosity index improver (excluding the component (F)) in the lubricating oil composition of the present invention, the blending amount is not limited as long as the composition satisfies the kinematic viscosity and viscosity index specifications at 100 ° C, Usually, it is 0.1 to 15% by mass, preferably 0.5 to 5% by mass based on the total amount of the composition.
The lubricating oil composition has a viscosity index of 165 or more, but is preferably 175 or more, more preferably 180 or more, and most preferably 190 or more from the viewpoint of fuel saving effect.

  As the extreme pressure agent, in addition to the phosphorus compound of component (B), at least one sulfur-based electrode selected from sulfurized fats and oils, sulfurized olefins, dihydrocarbyl polysulfides, dithiocarbamates, thiadiazoles, and benzothiazoles A pressure agent can be blended.

As the dispersant, in addition to the boron-modified ashless dispersant of component (D), succinimide, benzylamine, polyamine, or their acid-modified compound or sulfur-modified compound having a hydrocarbon group having 40 to 400 carbon atoms, etc. An ashless dispersant can be blended.
In the present invention, one or two or more compounds arbitrarily selected from the above dispersants can be contained in any amount, but the content is usually 0.01 based on the total amount of the composition. -20% by mass, preferably 0.1-10% by mass. When the content of the ashless dispersant exceeds 20% by mass, the low temperature fluidity of the lubricating oil composition is greatly deteriorated, which is not preferable.

Examples of the metallic detergent include metallic detergents such as (C) component calcium salicylate and / or calcium sulfonate alkaline earth metal sulfonate, alkaline earth metal phenate, and alkaline earth metal salicylate.
In the present invention, one or two or more compounds arbitrarily selected from the above metal-based detergents can be contained in any amount, but the content is usually 0 based on the total amount of the composition. 0.01 to 10% by mass, preferably 0.1 to 5% by mass.

As the antioxidant, any phenolic compound or amine compound that is generally used in lubricating oils can be used.
Specifically, alkylphenols such as 2,6-di-tert-butyl-4-methylphenol and bisphenols such as methylene-4,4-bisphenol (2,6-di-tert-butyl-4-methylphenol) , Naphthylamines such as phenyl-α-naphthylamine, dialkyldiphenylamines, zinc dialkyldithiophosphates such as zinc di-2-ethylhexyldithiophosphate, (3,5-di-tert-butyl-4-hydroxyphenyl) fatty acid ( Propionic acid etc.) or (3-methyl-5-tertbutyl-4-hydroxyphenyl) fatty acid (propionic acid etc.) and mono- or polyhydric alcohols such as methanol, octanol, octadecanol, 1,6-hexadiol, Neopentyl glycol, thiodiethylene glycol Triethylene glycol, esters of pentaerythritol and the like.
One or two or more compounds arbitrarily selected from these can be contained in any amount, but usually the content is 0.01 to 5 mass based on the total amount of the lubricating oil composition. %, Preferably 0.1 to 3% by mass.

  Examples of the corrosion inhibitor include benzotriazole, tolyltriazole, thiadiazole, and imidazole compounds.

  Examples of the rust inhibitor include petroleum sulfonate, alkylbenzene sulfonate, dinonylnaphthalene sulfonate, alkenyl succinic acid ester, and polyhydric alcohol ester.

  Examples of the demulsifier include polyalkylene glycol nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene alkyl naphthyl ether.

  Examples of metal deactivators include imidazoline, pyrimidine derivatives, alkylthiadiazoles, mercaptobenzothiazoles, benzotriazoles or derivatives thereof, 1,3,4-thiadiazole polysulfide, 1,3,4-thiadiazolyl-2,5-bis. Examples include dialkyldithiocarbamate, 2- (alkyldithio) benzimidazole, and β- (o-carboxybenzylthio) propiononitrile.

  As the antifoaming agent, any compound usually used as an antifoaming agent for lubricating oil can be used, and examples thereof include silicones such as dimethyl silicone and fluorosilicone. One or two or more compounds arbitrarily selected from these can be blended in any amount.

  As the seal swelling agent, any compound usually used as a seal swelling agent for lubricating oil can be used, and examples thereof include ester-based, sulfur-based and aromatic-based seal swelling agents.

  As the colorant, any compound that is usually used can be used, and any amount can be blended. Usually, the blending amount is 0.001 to 1.0% by mass based on the total amount of the composition. is there.

  When these additives are contained in the lubricating oil composition of the present invention, the content is based on the total amount of the composition, and 0.005 to 5% by mass for each of the corrosion inhibitor, rust inhibitor, and demulsifier, metal It is usually selected in the range of 0.005 to 2% by mass for the deactivator, 0.01 to 5% by mass for the seal swelling agent, and 0.0005 to 1% by mass for the antifoaming agent.

  The lubricating oil composition of the present invention can be used in various applications such as a manual transmission for automobiles, an automatic transmission, a continuously variable transmission, a final reduction gear, an engine oil, an agricultural machine, and a construction machine. Most preferably used is a continuously variable transmission. This is because there are many places where shearing is applied in lubrication and the surface pressure is also high, so that the performance of the present invention can be used most effectively.

  Hereinafter, the content of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these.

(Examples 1-4, Comparative Examples 1-3)
About the lubricating oil composition of the present invention (Examples 1 to 4) and the comparative lubricating oil composition (Comparative Examples 1 to 3), viscosity temperature characteristics, EC × V40, shear test (JASO ultrasonic method, 20 hours) Table 1 shows the results of the viscosity reduction rate and the traction coefficient.

(Examples 5 to 12, Comparative Examples 4 to 10)
For the lubricating oil compositions (Examples 5 to 12) of the present invention and comparative lubricating oil compositions (Comparative Examples 4 to 10), the friction coefficient between metals, the speed change clutch characteristics (static friction coefficient, μ ₀ / μ _d ), Table 2 shows the results of shudder prevention.

  As shown in Tables 1 and 2, the lubricating oil composition of the present invention has a high coefficient of friction between metals, is excellent in transmission clutch characteristics and anti-shudder properties, and can achieve further fuel savings due to a low traction coefficient.

  The lubricating oil composition of the present invention is excellent in fuel economy and can be suitably used for a continuously variable transmission, and is also usefully used for a manual transmission, an automatic transmission, and a final reduction gear.

Claims (2)

The product (EC × V40) of the weight percent (EC (wt%)) of the saturated cyclic component and the kinematic viscosity (V40 (mm ² / s)) at 40 ° C. based on the total amount of the base oil is 500 or less, and the kinematic viscosity at 100 ° C. In a base oil whose viscosity is adjusted to 3.6 to 4.1 mm ² / s, (B) 0.01 to 0.03% by mass of phosphorus compound as phosphorus element amount, (C) calcium salicylate and / or Calcium sulfonate is contained in an amount of 0.03 to 0.05% by mass as the amount of calcium element, the elemental ratio (P / Ca) of phosphorus and calcium in the lubricating oil composition is 0.3 to 0.7, (D 100) of the lubricating oil composition containing 0.001 to 0.008% by mass of boron-modified ashless dispersant as the amount of boron element, and (E) 0.01 to 2% by mass of the friction modifier based on the total amount of the composition. The kinematic viscosity at 5 ° C is 5.2 to 5. mm 2 / ^s, the continuously variable transmission lubricating oil composition characterized by a viscosity index of 165 or more.   The lubricating oil composition for continuously variable transmission according to claim 1, wherein the component (E) is a fatty acid ester friction modifier and / or a fatty acid amide friction modifier.