JP4810492B2 - 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 used for a push belt type continuously variable transmission. In particular, in a push belt type continuously variable transmission, the present invention relates to a lubricating oil composition having a high coefficient of friction between metals and excellent wear prevention performance.

  The number of push belt type continuously variable transmissions (hereinafter sometimes referred to as belt type CVTs) has been increasing rapidly in recent years because it is effective in improving fuel efficiency and drivability of automobiles. However, since it is difficult to obtain a large transmission torque capacity, the belt type CVT can be conventionally mounted only on a small vehicle having a displacement of 1600 cc or less. Improvement of the transmission torque capacity is an important issue for the belt type CVT.

In the belt type CVT, torque is transmitted by the frictional force between the belt element and the pulley. Therefore, the transmission torque capacity is determined by the friction coefficient between the belt element and the pulley and the pressing force of the pulley. This inter-metal friction coefficient depends on the performance of the lubricating oil. If the inter-metal friction coefficient is insufficient, there is a possibility that a slip occurs between the belt and the pulley or the belt breaks.
On the other hand, an electromagnetic clutch has been conventionally used for the starting mechanism of the belt type CVT. However, a torque converter with a wet clutch or a lock-up clutch has been used to cope with an increase in transmission torque due to a large displacement and to improve drivability. Are beginning to be used. Since these wet clutches, torque converters, and CVTs use a common lubricant, continuously variable transmission lubricants (CVT oils) are also important for compatibility with these wet clutches and torque converters. ing.

  Under these circumstances, automatic transmission oil (hereinafter sometimes referred to as ATF) has often been used as conventional CVT oil. This is because the transmission torque is small and the required level of friction coefficient between metals is not so high in a conventional small displacement vehicle, so performance can be improved by selecting an ATF with a relatively high friction coefficient between metals. It was because I was satisfied. An advantage of diverting ATF is that it has a track record in compatibility with wet friction materials and compatibility with other materials. However, when the belt type CVT is installed in a car with a large displacement, the required level of friction coefficient between metals becomes high, and the performance cannot be satisfied with the diversion of ATF. Oil is needed.

  Furthermore, in order to efficiently transmit the engine output with the belt type CVT, it is necessary to prevent slipping between the belt and the pulley. However, if the pressure for sandwiching the belt is increased to prevent slipping, the belt will be easily worn. . For this reason, not only the improvement of the apparatus surface but also the lubricating oil is required to prevent slippage between the belt and the pulley and to prevent the belt and the pulley from being worn.

Conventionally, in a continuously variable transmission lubricating oil, for example, in Patent Document 1, a lubricating oil composition in which an antiwear agent, a metal detergent, and a friction modifier having a carboxyl group are blended, and in Patent Document 2, a sulfur-based electrode is used. A continuously variable transmission composition containing a pressure agent, a phosphorus-based extreme pressure agent, and a metal detergent, Patent Document 3 discloses a continuously variable transmission containing an ashless dispersant, a sulfur-based extreme pressure agent, and a phosphorus-based extreme pressure agent. Lubricating oil composition for machinery, Patent Document 4 describes a lubricating oil composition for a belt-type CVT automatic transmission in which a total base number is blended with Ca sulfonate and phosphites having a specific range, Patent Document 5 discloses a specific range. And a lubricating oil composition for belt type continuously variable transmissions that contains a metal detergent and zinc dialkyldithiophosphate, and in Patent Document 6, imide compound and zinc alkyldithiophosphate are blended in Patent Document 6. Invariant Such as machine oil compositions have been proposed. However, in spite of these proposals, there is still nothing satisfying a sufficient high level of intermetal friction coefficient and excellent wear resistance for belts and pulleys. In particular, a lubricant for belt type continuously variable transmissions (CVT oil) is required to have a high coefficient of friction between metals, so a metal detergent is blended. However, some anti-wear agents blended to improve anti-wear properties have insufficient anti-wear properties due to interactions with metal detergents if the amount is too small. If the blending amount is too large, there is a problem that the coefficient of friction between metals decreases.
JP-A-2-175794 Japanese Patent Application Laid-Open No. 9-1000048 Japanese Patent Laid-Open No. 10-8081 Japanese Patent Laid-Open No. 10-306292 JP-A-11-80772 JP-A-11-181464

  In view of the development situation as described above, the object of the present invention is to provide a lubricating oil composition for a continuously variable transmission that satisfies both a high intermetal friction coefficient required for a belt-type CVT oil and an excellent anti-wear property for a belt and a pulley. Is to provide things.

As a result of intensive studies on the above problems, the present inventors have found that (A) at least one of phosphoric acid esters or phosphites, (B) thiophosphoric acid esters or thiophosphorous acids. By blending at least one ester, (C) a specific polyamine compound , and (D) oleylamine as an essential component as a friction modifier, a high intermetallic friction coefficient and excellent required as a lubricating oil for continuously variable transmissions It has been found that a lubricating oil composition for continuously variable transmissions having both excellent wear prevention properties can be obtained. The present invention has been completed based on this finding.

（式中、Ａは、ＮＨ _２ であり、Ｒ ^１ は、アルキレン基であり、Ｒ ^２ は、Ｈであり、ｎは、２〜２０の整数である。）
また、本発明の第２の発明によれば、第１の発明において、さらに、（Ｅ）金属清浄剤を配合することを特徴とする無段変速機用潤滑油組成物が提供される。
さらに、本発明の第３の発明によれば、第２の発明において、（Ｅ）金属清浄剤が、アルカリ土類金属のスルホネートであることを特徴とする無段変速機用潤滑油組成物が提供される。
さらに、本発明の第４の発明によれば、第１乃至第３のいずれかの発明において、さらに、（Ｆ）オレフィンコポリマーを配合することを特徴とする無段変速機用潤滑油組成物が提供される。 That is, according to the first invention of the present invention, at least one of (A) an acidic phosphate ester, (B) a thiophosphate ester or a thiophosphite ester is added to the lubricating base oil composed of mineral oil and / or synthetic oil. There is provided a lubricating oil composition for a continuously variable transmission, comprising (C) a polyamine compound represented by the following general formula (9) , and (D) oleylamine as a friction modifier .

(In the formula, A is NH ₂ , R ¹ is an alkylene group, R ² is H, and n is an integer of 2 to 20.)
According to a second aspect of the present invention, there is further provided a lubricating oil composition for continuously variable transmission, characterized in that, in the first aspect, (E) a metal detergent is further blended.
Further, according to a third invention of the present invention, there is provided the lubricating oil composition for continuously variable transmission according to the second invention, wherein (E) the metal detergent is an alkaline earth metal sulfonate. Provided.
Furthermore, according to the fourth aspect of the present invention, there is provided a lubricating oil composition for continuously variable transmissions according to any one of the first to third aspects, further comprising (F) an olefin copolymer. Provided.

As described above, the present invention relates to a lubricating oil composition in which at least three kinds of specific compounds are blended with a lubricating base oil. Preferred embodiments thereof include the following.
(I) The continuously variable transmission is a push belt type continuously variable transmission, the lubricating oil composition for a continuously variable transmission described above.
(Ii) (B) Said lubricating oil composition for continuously variable transmissions, wherein the thiophosphate or thiophosphite is a short-chain alkylthiophosphate or a short-chain alkylthiophosphite.
(Iii) The lubricating oil composition for a continuously variable transmission, wherein the (B) thiophosphate is a bisdithiophosphate.
(Iv) The above-mentioned lubricating oil composition for continuously variable transmission, wherein the (D) olefin copolymer is non-dispersed.

The lubricating oil composition for continuously variable transmissions of the present invention, particularly the lubricating oil composition for push belt type continuously variable transmissions, contains a specific additive, that is, (A) acidic phosphate ester, B) At least one kind of thiophosphate ester or thiophosphite ester, (C) a specific polyamine compound , and (D) oleylamine as a friction modifier , or (E) a metal detergent, preferably By blending an alkaline earth metal sulfonate , or by further blending (F) an olefin copolymer, the high intermetallic friction coefficient and excellent wear resistance required for continuously variable transmission lubricants can be obtained. There is a remarkable effect that it can be obtained.

Hereinafter, the present invention will be described in detail.
(1) Lubricating base oil The base oil used in the lubricating oil composition for continuously variable transmissions of the present invention is not particularly limited, and any base oil that is generally used as a lubricating base oil can be used. be able to. That is, those corresponding to these include mineral oil, synthetic oil, or a mixed oil thereof.
The base oil used in the present invention has a kinematic viscosity of 0.5 to ²⁰⁰ mm ² / s at 100 ° C., and a preferable kinematic viscosity is in the range of ^{2 to} 25 mm ² / s, and more preferable kinematic viscosity. Is in the range of 2.5-8 mm ² / s. If the kinematic viscosity of the base oil is too high, the low-temperature viscosity deteriorates. Conversely, if the kinematic viscosity is too low, there is a problem that the sliding portion of the continuously variable transmission is worn or the flash point is lowered.
Mineral oil is a hydrocarbon oil fraction having a lubricating oil viscosity. For example, raffinate obtained by treating a vacuum distillation distillate with an aromatic extraction solvent such as phenol, furfural, N-methylpyrrolidone, propane, After dewaxing with a solvent such as methyl ethyl ketone, if necessary, hydrocarbon oil obtained by further hydrorefining, or this hydrocarbon distillate and solvent extraction, solvent dewaxing and solvent dewaxing Mixtures with residual oil can be used. From the viewpoint of oxidative stability, the ratio of aromatic carbon number to total carbon,% C _A (ASTM D3238 method) is preferably 20 or less, particularly preferably 10 or less. From the viewpoint of the pour point, those having a pour point of −10 ° C. or lower are preferred, and those having a −15 ° C. or lower are particularly preferred. These refined mineral oils are paraffinic or naphthenic in composition, and may be single or mixed hydrocarbons thereof. Specific examples of the mineral oil include light neutral oil, medium neutral oil, heavy neutral oil, bright stock, and the like, and the base oil can be adjusted by appropriately mixing so as to satisfy the required performance.

Examples of the synthetic oil used in the present invention include olefin oligomers, dibasic acid esters, polyol esters, polyalkylene glycols, polyethers, alkylbenzenes, and alkylnaphthalenes.
The olefin oligomer is obtained by copolymerizing any one kind selected from linear or branched olefin hydrocarbons having 2 to 14 carbon atoms, preferably 4 to 12 carbon atoms, or two or more kinds. Selected from products having an average molecular weight of 100 to about 3,000, preferably 200 to about 1,000, but those having unsaturated bonds removed by hydrogenation are particularly preferred. Preferred specific olefin oligomers include, for example, polybutene, α-olefin oligomers, ethylene / α-olefin oligomers, and the like.
Examples of the dibasic acid ester include esters of an aliphatic dibasic acid having 4 to 14 carbon atoms and an aliphatic alcohol having 4 to 14 carbon atoms. Examples of the polyol ester include esters of polyhydric alcohols such as neopentyl glycol, trimethylolpropane, pentaerythritol, and fatty acids having 4 to 18 carbon atoms. Also, esters of hydroxy acids such as hydroxypivalic acid, fatty acids and alcohols can be used.
As an example of polyoxyalkylene glycol, a polymer of alkylene oxide having 2 to 4 carbon atoms can be used, and the alkylene oxide may be a single polymerization or a mixture polymerization. Moreover, the polymer by the mixture of alkylene oxides may be a block polymer or a random polymer. Further, the terminal group of alkylene glycol may be ether-blocked or ester-blocked at one or both ends. As the polyether, phenyl ether or the like can be used.
These base oils can be used alone or in combination of two or more kinds, and mineral oil and synthetic oil may be used in combination.

(2) Additive component Next, the essential components (A), (B) , (C) and (D) used in the base oil used in the lubricating oil composition for continuously variable transmission of the present invention. The components (E) and (F) that are preferably further blended will be described.

(I) (A) component In the lubricating oil composition for continuously variable transmission of this invention, (A) component used as an essential component is at least 1 type of phosphate ester or phosphite.
As the phosphoric acid ester or phosphite ester of component (A), phosphoric acid ester, acidic phosphoric acid ester, phosphorous acid ester, acidic phosphorous acid ester, acidic phosphoric acid ester amine salt, acidic phosphorous acid ester amine Salt. In the present invention, these compounds can be used alone, or several of these compounds can be used in combination.
The phosphate ester or acidic phosphate ester is usually represented by the following general formula (1).

In the above formula, R ¹ is a hydrocarbon group having 1 to 24 carbon atoms, and may be the same or different in the formula. x is 1 or 2 . Preferred hydrocarbon groups are alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, aryl groups having 6 to 20 carbon atoms, alkylaryl groups, and arylalkyl groups, and particularly preferred are those having 1 to 1 carbon atoms. 8 short chain alkyl groups.

  Specifically, as the phosphate ester, there are triaryl phosphate, trialkyl phosphate, and the like, for example, compounds such as benzyl diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, tributyl phosphate, ethyl dibutyl phosphate, and triethyl phenyl phosphate. Can be mentioned.

  Examples of the acidic phosphate ester include methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, n-butyl acid phosphate, 2-ethylhexyl acid phosphate, di-2-ethylhexyl phosphate, isodecyl acid phosphate, lauryl acid phosphate, Mention may be made of compounds such as decyl acid phosphate, stearyl acid phosphate, and oleyl acid phosphate.

(A) As a compounding quantity of the acidic phosphoric acid ester of a component, 100-500 ppm is suitable as P amount on the composition whole quantity basis, and if it is less than 100 ppm, the improvement effect of the friction coefficient between metals will be small, and wear prevention property will also be sufficient as it. It is insufficient. On the other hand, if the blending amount exceeds 500 ppm, the material compatibility deteriorates.

(Ii) Component (B) In the lubricating oil composition for continuously variable transmission of the present invention, the component (B) used as an essential component is at least one of thiophosphates or thiophosphites.
As the thiophosphate ester or thiophosphite ester of component (B), thiophosphate ester, thioacid phosphate ester, thiophosphite ester, thioacid phosphite ester, thioacid phosphate ester amine salt, Acid phosphite amine salts are mentioned. In the present invention, these compounds can be used alone, or several of these compounds can be used in combination.
Examples of thiophosphates (thiophosphates) include thiophosphates and thioacid phosphates represented by the following general formula (5).

In the above formula, R ¹ is hydrogen or a hydrocarbon group having 1 to 24 carbon atoms, and may be the same or different in the formula, but at least one is a hydrocarbon group ( All are not hydrogen). X ¹ to X ⁴ represents an oxygen atom or a sulfur atom, at least one is a sulfur atom. Preferred hydrocarbon groups are alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, aryl groups having 6 to 20 carbon atoms, alkylaryl groups, and arylalkyl groups, and particularly preferred are those having 1 to 1 carbon atoms. 8 short chain alkyl groups.

  Examples of the thiophosphates include bisthiophosphates and bisdithiophosphates represented by the following general formula (6). In the present invention, bisdithiophosphates are preferred embodiments. Can be used as

In the above formula, R is hydrogen or a hydrocarbon group having 1 to 24 carbon atoms, and may be the same or different in the formula, but at least one is a hydrocarbon group (that is, All are not hydrogen). X ¹ to X ⁷ represents an oxygen atom or a sulfur atom, at least one is a sulfur atom. n is an integer of 1 or 2. Preferred hydrocarbon groups are alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, aryl groups having 6 to 20 carbon atoms, alkylaryl groups, and arylalkyl groups, and particularly preferred are those having 1 to 1 carbon atoms. 8 short chain alkyl groups.

  Examples of thiophosphites (thiophosphites) include thiophosphites and thioacid phosphites represented by the following general formula (7).

In the above formula, R ¹ is hydrogen or a hydrocarbon group having 1 to 24 carbon atoms, and may be the same or different in the formula, but at least one is a hydrocarbon group ( All are not hydrogen). X ¹ to X ³ represents an oxygen atom or a sulfur atom, at least one is a sulfur atom. Preferred hydrocarbon groups are alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, aryl groups having 6 to 20 carbon atoms, alkylaryl groups, and arylalkyl groups, and particularly preferred are those having 1 to 1 carbon atoms. 8 short chain alkyl groups.

  Furthermore, as the component (B), a thioacid phosphate amine salt or a thioacid phosphate amine amine salt is also used. These are expressed by, for example, the following general formula (8).

In the above formula, R ¹ is hydrogen or a hydrocarbon group having 1 to 24 carbon atoms, and may be the same or different in the formula, but at least one is a hydrocarbon group ( All are not hydrogen). Preferred hydrocarbon groups are alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, aryl groups having 6 to 20 carbon atoms, alkylaryl groups, and arylalkyl groups, and particularly preferred are those having 1 to 1 carbon atoms. 8 short chain alkyl groups. X ¹ and X ² represent an oxygen atom or a sulfur atom, and at least one is a sulfur atom. R ² is an alkyl group or alkylene group having 4 to 20 carbon atoms, an alkanol group having 2 to 12 carbon atoms, or an aryl group or alkyl-substituted aryl group having 6 to 20 carbon atoms, and R ³ is a hydrogen atom, carbon These are an alkyl group or alkylene group having 4 to 20 carbon atoms, an alkanol group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an alkyl-substituted aryl group.

  (B) As a compounding quantity of the thiophosphate ester or thiophosphite ester of a component, 100-500 ppm is suitable as P amount on the composition whole quantity basis, and if it is less than 100 ppm, the effect of improving the friction coefficient between metals will be achieved. It is small and wear resistance is insufficient. On the other hand, if the blending amount exceeds 500 ppm, the material compatibility deteriorates.

(Iii) Component (C) In the lubricating oil composition of the present invention, the component (C) used as an essential component is a polyamine compound and is represented by the following general formula (9). The structural feature of this polyamine compound is that it has a polyalkylamine structure in the molecule.

In the general formula (9), A is NH ₂ . R ¹ is an alkylene group, preferably an ethylene group, a propylene group, or a butylene group. R ² is H. n is an integer of 2-20.

(C) The compounding quantity of the polyamine compound of a component is the range of 0.01-10 weight% on the composition whole quantity basis. If the blending amount is less than 0.01% by weight, the effect of improving the friction coefficient between metals is small, whereas if it exceeds 10% by weight, the friction coefficient between metals corresponding to the blending amount is not improved, but rather oxidation stability. There is a risk of worsening.
(Iv) Component (D)
The (D) component friction modifier is oleylamine. The blending amount of the friction modifier is preferably 0.01 to 5% by weight based on the total amount of the composition. If the blending amount is less than 0.01% by weight, the desired effect is not exhibited, while 5% by weight. If it exceeds%, the friction coefficient between metals decreases.

(V) Component (E)
In the lubricating oil composition for continuously variable transmission of the present invention, a metal detergent is preferably used as the component (E). The metal detergent has an alkaline earth metal or alkali metal in the molecule, and is dissolved or uniformly dispersed in the lubricating base oil, for example, at least one chain hydrocarbon group of the alkaline earth metal A salicylate, a carboxylate, a sulfonate, a phenate or a phosphonate having, specifically, an alkaline earth metal salt of alkyl salicylic acid, or an alkaline earth metal salt of naphthenic acid or phthalic acid having a substituent such as alkyl Or alkaline earth metal salts of petroleum sulfonic acids or alkylbenzene or alkylnaphthalene sulfonic acids, alkaline earth metal salts of sulfurized alkylphenols, or alkaline earth metal salts of thiophosphonic acid or phosphonic acid having a hydrocarbon group Calcium (Ca) salt, magnesium (Mg) salt, barium Ba) salt is preferably used. Alkali metal salicylates, carboxylates, sulfonates, phenates or phosphonates are also used, and examples of the alkali metals include sodium (Na) and potassium (K). Of these, alkaline earth metal sulfonates are preferably used. The metal detergent usually has a total base number (TBN) [JIS K2501 (perchloric acid method)] in the range of 10 to 450 mgKOH / g, preferably in the range of 20 to 400 mgKOH / g. A soap content of 20 to 50% by weight can be used, but a soap content of 30 to 45% by weight is particularly preferred. When these are used alone or in combination, the friction characteristics with the wet friction material may be more preferable than when used alone. As a compounding quantity of a metal detergent, 100-1000 ppm is used suitably as a metal quantity on the composition whole quantity basis.
(Vi) Component (F) In the lubricating oil composition for continuously variable transmission of the present invention, an olefin copolymer is preferably used as the component (F) .

  The olefin copolymer (or olefin copolymer) is an oil-soluble one obtained by random copolymerization of two or more olefin monomers, and examples thereof include an ethylene-α-olefin copolymer. As the ethylene-α-olefin copolymer, a copolymer of ethylene and a linear or branched α-olefin having 3 to 20 carbon atoms is preferable. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, Examples thereof include 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene and branched olefins thereof. In particular, an ethylene-propylene copolymer using propylene is present. This is effective for achieving the object of the invention.

In the present invention, an olefin copolymer having a weight average molecular weight of 3.0 × 10 ^{4 to} 1.0 × 10 ⁵ is preferably used. When the weight average molecular weight of the olefin copolymer is less than 3.0 × 10 ⁴ , the effect of increasing the viscosity is small, while when it exceeds 1.0 × 10 ⁵ , the shear stability is inferior, resulting in a decrease in viscosity and an intermetallic friction coefficient. affect. The weight average molecular weight of the olefin copolymer is measured by gel permeation chromatography and expressed in terms of polystyrene.

  As the olefin copolymer, either a dispersion type or a non-dispersion type can be used, and is not particularly limited. However, in terms of the coefficient of friction between metals, a non-dispersion type having no polar group in the molecule is preferable. preferable. One olefin copolymer may be used, or two or more olefin copolymers may be mixed and used. In addition to ethylene and α-olefin, a copolymer using a diolefin as a third component of the copolymerization can also be used. Examples of the diolefin include bicyclic, alicyclic or aliphatic conjugated diolefins having 6 to 12 carbon atoms such as 1,5-cyclooctadiene, 1,4-cyclohexadiene, dicyclopentadiene, 2-norbornene and the like. be able to.

As a method for producing an olefin copolymer, a conventionally known method can be employed. For example, an ethylene-propylene copolymer is prepared by using ethylene and propylene in a solvent in the presence of a Ziegler-Natta catalyst soluble in the solvent. Can be used as monomers. The molecular weight of the olefin copolymer, which is essential as the component (F) of the lubricating oil composition for continuously variable transmission of the present invention, is secured by selecting the polymerization conditions, that is, the type of solvent, the proportion of monomer, the catalyst concentration, the temperature, and the like. be able to.

In the present invention, the olefin copolymer having a weight average molecular weight of the component (F) of 3.0 × 10 ^{4 to} 1.0 × 10 ⁵ may be used singly or in combination of two or more. The blending amount is selected in the range of 0.5 to 10.0% by weight based on the total amount of the composition. The blending amount is particularly preferably in the range of 1.0 to 9.0% by weight. When the blending amount is less than 0.5% by weight, the effect of improving the viscosity index is small, and when it exceeds 10.0% by weight, it is difficult to adjust the viscosity as a lubricating oil composition for continuously variable transmission.

CVT lubricating oil composition of the present invention, the above (A), (B), by containing as the component (C) and (D) the coexistence of components, essential components, or further By including the component (E) and the component (F) as essential components, there is a remarkable effect that a high intermetal friction coefficient required for a continuously variable transmission lubricating oil can be obtained.

(3) Other additive components The lubricating oil composition of the present invention comprises the above compound as an essential component or a more preferable component in a lubricating base oil. Various additives as shown below, that is, friction modifier excluding oleylamine , ashless dispersant, metal deactivator, antioxidant, viscosity index improver, pour point depressant, antifoaming agent, Corrosion inhibitors, colorants, and the like can be added as appropriate within a range that does not impair the object of the present invention.

As a friction modifier excluding oleylamine , a boron-containing alcohol friction modifier can be preferably used. In addition, amide compounds, imide compounds, boron-containing cyclic carboxylic acid imides, and the like can also be suitably used. As the boron-containing alcohol friction modifier, aliphatic monoalcohol, aliphatic polyhydric alcohol, or a reaction product of alkylene glycol and boric acid can be used. The blending amount of the friction modifier is preferably 0.01 to 5% by weight based on the total amount of the composition. If the blending amount is less than 0.01% by weight, the desired effect is not exhibited, while 5% by weight. If it exceeds%, the friction coefficient between metals decreases.

  Examples of the ashless dispersant include imide compounds such as monoimide and bisimide, and those obtained by treating succinimide or succinimide with a boron compound are preferable, and a boron-containing material of polyalkyl or polyalkenyl succinimide Particularly preferred. These are usually used in a proportion of 0.1 to 10% by weight.

  As the metal deactivator, benzotriazole, thiadiazole and derivatives thereof can be suitably used, and the combined use of the benzotriazole type and the thiadiazole type is particularly preferable because it exhibits excellent oxidative stability when used in combination. These are usually used in a proportion of 0.001 to 3% by weight.

  As the antioxidant, hindered phenols and amines can be preferably used, and using them in combination is particularly preferable because the oxidation stability is remarkably improved. As the phenolic antioxidant, 4 methyl 2,6 ditertiary butylphenol, 4,4-methylenebis 2,6 ditertiary butylphenol, and the like can be suitably used. As the amine-based antioxidant, phenyl α-naphthylamine, alkylphenyl α-diphenylamine, diphenylamine, alkyldiphenylamine and the like can be suitably used. These are usually used in a proportion of 0.05 to 5% by weight.

  In the present invention, the above-mentioned olefin copolymer (component (D)) is preferably used as the viscosity index improver, but the viscosity index improver other than the olefin copolymer is appropriately added in an amount of 1 to 10 based on the total amount of the composition. It can be used in the range of wt%. Any type of viscosity index improver can be used. For example, a dispersion type polymethacrylate viscosity index improver having a number average molecular weight of 5,000 to 200,000 can be used, and an average molecular weight of 100,000 or less can be suitably used from the viewpoint of shear stability. In this case, the dispersion type polymethacrylate viscosity index improver preferably contains about 5 to 20 mol% of a polar monomer. Examples of the polar monomer include amines such as diethylaminoethyl methacrylate and 2-methyl-5-vinylpyridine, N -Nitrogen compounds such as vinylpyrrolidinone can be preferably used. Other examples include non-dispersed polyacrylates and polymethacrylate-based viscosity index improvers. From the viewpoint of low-temperature viscosity, combined use with non-dispersed polymethacrylate-based viscosity index improvers is preferred.

  Pour point depressants generally include ethylene-vinyl acetate copolymers, condensates of chlorinated paraffin and naphthalene, condensates of chlorinated paraffin and phenol, polymethacrylate, polyalkylstyrene, etc. Methacrylate is preferably used. These are usually used in a proportion of 0.01 to 5% by weight.

  As the antifoaming agent, silicone compounds such as dimethylpolysiloxane, ester compounds such as sorbitan monolaurate and alkenyl succinic acid derivatives can be used. These are usually used in a proportion of 0.0001 to 2% by weight.

  As an example of the belt type CVT in the present invention, there is a CVT using a metal belt manufactured by Van Doorne 'Transmissie BV, but the belt type CVT in the present invention is not necessarily manufactured by Van Doorne' Transmissie BV. However, the present invention is not limited to CVT using a belt, and can be used for a similar mechanism, that is, CVT that transmits power by utilizing friction between metals.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not particularly limited to these examples. In addition, the measurement of the friction coefficient between metals and evaluation of wear prevention property in an Example and a comparative example were measured and evaluated by the method shown next.

(1) Coefficient of friction between metals and wear resistance SRV friction tester (reciprocating friction tester) was used as a tester, and the test was conducted under the following test conditions. Friction coefficient maximum value) was measured. It was judged that the higher the friction coefficient between metals, the larger the transmission torque capacity, and those having a friction coefficient between metals of 0.19 or more were acceptable. The anti-wear property was evaluated by measuring the wear marks on the plate at the end of the test with a stylus type surface roughness meter. Those with clear wear marks are evaluated as having wear and are judged to be inferior in wear prevention.
[Test conditions]
-Test piece: Ball (SUJ2), plate (SUJ2)
Test temperature: 100 ° C
・ Load: 100N
・ Frequency: 50Hz
・ Stroke: 1mm

(2) Examples and Comparative Examples [Example 1]
As a base oil, a solvent-refined paraffinic mineral oil (kinematic viscosity at 100 ° C., 4 mm ² / s) is used. To this mineral oil, based on the total amount of the composition, (A) component phosphate ester or phosphite ester As an at least one kind, 0.3 wt% of an acidic phosphate ester (n-butyl acid phosphate: (C ₄ H ₉ O) _n P (O) (OH) _{3 -n} n = 1, 2), (B) As at least one of the component thiophosphates or thiophosphites, thiophosphates represented by the following structural formula (10), that is, in the above general formula (6), X ¹ , X ⁴ , X ⁷ is sulfur ^{(S), X 2, X} 3, X 5, X 6 is an oxygen (O), R is butyl radical, n is 0.3 wt% to Bisujichiorin ester is of 2, (C ) Component polyamine compounds include the following 0.1% by weight of the polyamine represented by the formula (11) and 5.0% by weight of the non-dispersed olefin copolymer having an average molecular weight of 40,000 as the olefin copolymer of the component (D) As the agent, 0.5% by weight of Ca sulfonate having a total base number (TBN) of 300 mgKOH / g, 0.02% by weight of oleylamine as a friction modifier, and antioxidant, ashless dispersant as other additives A lubricating oil composition containing 1.5% by weight in total of a certain amount of each of a metal deactivator and an antifoaming agent was prepared.

  The prepared lubricating oil composition was subjected to measurement and evaluation of a friction coefficient between metals and wear marks. The evaluation results are shown in Table 1. The friction coefficient between metals of Example 1 is 0.195, which is good, and wear marks are not recognized, and wear resistance is also good.

[Example 2]
Similarly to Example 1, the base oil component and additive component shown in Table 1 were blended in the proportions shown in the same table to prepare a lubricating oil composition. In particular, as the viscosity index improver, disperse type polymethacrylate was used in place of the olefin copolymer of component (D) of Example 1. The prepared lubricating oil composition was subjected to measurement and evaluation of a friction coefficient between metals and wear marks. These results are shown in Table 1. Similar to Example 1, the evaluation result of Example 2 is good.

[Comparative Examples 1-3]
A base oil component and various additive components shown in Table 1 were blended in the proportions shown in the same table to prepare a lubricating oil composition. The prepared lubricating oil composition was subjected to measurement and evaluation of a friction coefficient between metals and wear marks. These evaluation results are shown in Table 1.

From any of the above examples and comparative examples, in any of the examples, the additives (A), (B), (C) and (D) , which are essential components in the present invention, and (F) an olefin copolymer are blended. As a lubricant for continuously variable transmissions, it became clear that high-quality lubricants satisfying the goals of a high coefficient of friction between metals and excellent wear resistance were obtained.
On the other hand, among the components (A), (B) , (C) and (D) , although three types are blended, in Comparative Examples 1 to 3 where all the essential components are not blended, high intermetal friction The coefficient is not obtained.

Claims (4)

In a lubricating base oil composed of mineral oil and / or synthetic oil, at least one of (A) acidic phosphate ester, (B) thiophosphate ester or thiophosphite ester, (C) the following general formula (9) A lubricating oil composition for a continuously variable transmission comprising the polyamine compound shown and (D) oleylamine as a friction modifier .

(In the formula, A is NH ₂ , R ¹ is an alkylene group, R ² is H, and n is an integer of 2 to 20.) Furthermore, (E) Metal detergent is mix | blended, The lubricating oil composition for continuously variable transmissions of Claim 1 characterized by the above-mentioned. The lubricating oil composition for continuously variable transmission according to claim 2, wherein the metal detergent (E) is an alkaline earth metal sulfonate. The lubricating oil composition for a continuously variable transmission according to any one of claims 1 to 3, further comprising (F) an olefin copolymer.