JP2011006705A - Lubricant composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricant composition for a stepless transmission making a high friction coefficient between metals required for belt type CVT oil and a shudder-preventing property to a slip control mechanism compatible with each other.SOLUTION: In the lubricant composition for the push belt type automatic stepless transmission obtained by compounding a metal salt of an organic acid (A), an abrasion inhibitor (B) and boron-containing succinimide (C) in lubricant base oil composed of mineral oil and/or synthetic oil, the metal salt of the organic acid (A) is sulfonate or phenate of Ca, Mg or Ba having at least one chain hydrocarbon group, linearity of the alkyl group in the chain hydrocarbon group obtained by a carbon nuclear magnetic resonance measurement (C-NMR) is 25 to 60%, and the abrasion inhibitor (B) is acidic phosphate or zinc dialkyldithio phosphate.

Description

  The present invention relates to a lubricating oil composition for an automatic transmission, and more particularly to a lubricating oil composition for a continuously variable transmission, and more particularly to a lubrication used in a push belt type continuously variable transmission having a torque converter with a lock-up clutch. It relates to an oil composition. In particular, in a push belt type continuously variable transmission having a torque converter with a lock-up clutch, the present invention relates to a lubricating oil composition that satisfies a large transmission torque capacity and excellent anti-shudder properties.

  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. In recent years, improvement of the belt has made it possible to mount it on a vehicle with a displacement of 2000 cc. However, improvement of the transmission torque capacity is still 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 intermetallic friction coefficient depends on the performance of the lubricating oil, and if the intermetallic friction coefficient is insufficient, there is a possibility that slipping may occur between the belt and the pulley or the belt may be broken.
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 lubricating oil, compatibility with these wet clutches and torque converters has also become important for CVT oils.

  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 displacement of 2000 cc, 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, depending on the mechanism of the lock-up clutch, it becomes impossible to use conventional CVT oil at all. This point will be described in more detail. A belt-type CVT for a displacement of 2000 cc vehicles having a torque converter with a lock-up clutch in the starting mechanism and a wet clutch in the forward / reverse switching mechanism is already on the market. However, in the future, the lock-up clutch is intentionally slipped by controlling the pressing pressure of the lock-up clutch for the purpose of further improving fuel efficiency by expanding the lock-up speed range and reducing the shock at the time of lock-up engagement. It is expected that a belt type CVT having a torque converter with a lock-up clutch having a function (hereinafter referred to as slip control) will be developed. When such slip control is performed, depending on the type of lubricating oil, self-excited vibration called “shudder” occurs, so the CVT oil needs to be prevented from being shuddered and to maintain its function. However, in order to satisfy the anti-shudder property, special additive compounding technology centering on the friction modifier is necessary. In addition to the ATF adjusted especially for the slip control ATF, sufficient anti-sudder prevention Does not show sex. In addition, many of the additives called friction modifiers that are blended as additives for imparting anti-shudder properties tend to lower the coefficient of friction between metals. Therefore, commercially available ATF having anti-shudder properties has a coefficient of friction between metals. Low and cannot be used for CVT. Therefore, a new additive blending technique is required to achieve both the intermetal friction coefficient and the anti-shudder property.

  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 phosphorous extreme pressure agent and a metal detergent, and in Patent Document 3, a lubricating oil composition containing an ashless dispersant, a sulfur extreme pressure agent and a phosphorus extreme pressure agent And Patent Document 4 propose a lubricating oil composition for a belt type CVT automatic transmission in which Ca sulfonate having a total base number in a specific range and phosphites are blended. However, in spite of these proposals, there is still nothing satisfying a sufficient high-level friction coefficient between metals, that is, a large transmission torque capacity and an excellent anti-suddering property for the slip control mechanism.

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

  An object of the present invention is to provide a lubricating oil composition for a continuously variable transmission that achieves both a high metal-to-metal friction coefficient required for a belt-type CVT oil and a shudder prevention property for a slip control mechanism in view of the development situation as described above. It is to be.

  As a result of intensive studies on the above problems, the inventors of the present invention have found that an organic acid metal salt (A) having a specific structure, an antiwear agent (B), and a boron-containing succinimide ( For the continuously variable transmission that combines the high inter-metallic friction coefficient required as a lubricant for continuously variable transmissions and the anti-suddering property against the slip control mechanism by blending at least three additives of C) as essential components It has been found that a lubricating oil composition can be obtained.

That is, according to the first invention of the present invention, an organic acid metal salt (A), an antiwear agent (B), and a boron-containing succinimide (C) are added to a lubricating base oil composed of mineral oil and / or synthetic oil. ), Wherein the organic acid metal salt (A) is a sulfonate or phenate of Ca, Mg or Ba having at least one chain hydrocarbon group, The linearity of the alkyl group in the chain hydrocarbon group determined by carbon nuclear magnetic resonance ( ¹³ C-NMR) measurement is 25 to 60%, and the antiwear agent (B) is an acidic phosphate ester or dialkyldithio Provided is a lubricating oil composition for a push belt type continuously variable transmission, characterized by being zinc phosphate.

According to the second invention of the present invention, the push belt according to the first invention, wherein the compounding amount of the organic acid metal salt (A) is 100 to 1000 ppm as a metal amount based on the total amount of the composition. A lubricating oil composition for a continuously variable transmission is provided.
Further, according to a third aspect of the present invention, in the first aspect, the continuously variable transmission is a push belt type having a torque converter with a lock-up clutch. A lubricating oil composition is 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 lubricant composition for a push belt type continuously variable transmission as described above, wherein the antiwear agent is a zinc dialkyldithiophosphate whose alkyl group is primary, secondary or a mixture thereof.
(Ii) The lubricating oil composition for a push belt type continuously variable transmission as described above, wherein the blending amount of the antiwear agent is 200 to 500 ppm as phosphorus (P) based on the total amount of the composition.
(Iii) The lubricating oil composition for a push belt type continuously variable transmission as described above, wherein the compounding amount of the boron-containing succinimide is 0.1 to 10% by weight based on the total amount of the composition.
(Iv) The lubricating oil composition for a push belt type continuously variable transmission as described above, wherein the total base number of the organic acid metal salt is 400 mgKOH / g or less.
(V) The continuously variable transmission is a push belt type having a torque converter with a lock-up clutch having a function of controlling a slip speed by controlling a pressing hydraulic pressure of the lock-up clutch. Lubricating oil composition for push belt type continuously variable transmission.

  The lubricating oil composition for automatic transmissions according to the present invention, in particular, the lubricating oil composition for continuously variable transmissions, has a high intermetallic friction coefficient and slip by adding three specific types of additives to the lubricating base oil. Excellent performance to achieve both anti-shudder performance for the control mechanism.

Hereinafter, the present invention will be described in detail.
(1) Lubricating base oil The base oil used in the lubricating oil composition for an automatic transmission according to the present invention is not particularly limited, and any base oil that is generally used as a lubricating base oil can be used. can. 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 3.5 to 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 wear occurs in the sliding portion of the automatic transmission or the flash point becomes low.
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) to (C) used in the base oil used in the lubricating oil composition of the present invention will be described.
The organic acid metal salt of the component (A) is a sulfonate or phenate having at least one chain hydrocarbon group of an alkaline earth metal, and specifically, petroleum sulfonic acid or sulfonic acid of alkylbenzene or alkylnaphthalene Alkaline earth metal salt of sulfurized alkylphenol or calcium (Ca) salt, magnesium (Mg) salt, or barium (Ba) salt.
The chain hydrocarbon group of the organic acid metal salt having at least one chain hydrocarbon group used as the component (A) of the present invention was determined by carbon nuclear magnetic resonance (hereinafter referred to as ¹³ C-NMR) measurement. It is desirable that the linearity of the alkyl group in the chain hydrocarbon group is 25 to 60%. Here, the linearity of the alkyl group means the ratio of the number of carbons in the linear part 5 or more from the end of the alkyl group or 4 or more from the branch to the total number of carbons in the alkyl group. The size depends on the bonding position of the aromatic group and the branching position of the alkyl group.
In the present invention, the alkyl group linearity is specifically determined from the following formula from ¹³ C-NMR measurement.

  When the linearity of the alkyl group is less than 25%, the anti-shudder performance is insufficient. On the other hand, when it exceeds 60%, the effect of increasing the friction coefficient between metals is lost.

  As other characteristics of the organic acid metal salt, those having a total base number of 400 mgKOH / g or less can be suitably used, and those having a total base number of 150 to 300 mgKOH / g are particularly preferable. 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. The organic acid metal salt has an alkyl group having 4 to 24 carbon atoms, and may be monoalkyl or dialkyl, but a mixture thereof can be preferably used. The length of the alkyl group is preferably 12 to 20 carbon atoms in order to achieve both a metal-to-metal friction coefficient and a shudder prevention property. As the compounding amount of the organic acid metal salt, 100 to 1000 ppm is preferable as the metal amount based on the total amount of the composition, and when the compounding amount is less than 100 ppm as the metal amount, the effect of improving the friction coefficient between metals is small, whereas 1000 ppm If it exceeds 1, oxidation stability will deteriorate.

  As the anti-wear agent for component (B), phosphorus anti-wear agents such as acidic phosphates can be used. The alkyl group may contain sulfur (S). Further, zinc dialkyldithiophosphates in which the alkyl group is primary, secondary, or a mixture thereof can also be used. Of these, acidic phosphate ester, zinc dialkyldithiophosphate or a mixture thereof is preferably used. The blending amount of the antiwear agent is preferably 200 to 500 ppm as the amount of phosphorus (P) based on the total amount of the composition, and if it is less than 200 ppm, the effect of improving the coefficient of friction between metals is small, and the antiwear property is insufficient. It is. On the other hand, if the blending amount exceeds 500 ppm, the material compatibility deteriorates.

Examples of the boron-containing succinimide as the component (C) used in the present invention include those obtained by treating a mono or bis succinimide with a boron compound. Particularly preferred are boron-containing materials of polyalkyl or polyalkenyl succinimides.
A polyalkyl or polyalkenyl succinimide can be produced by reacting a polyalkyl or polyalkenyl succinic anhydride, usually obtained by reaction of a polyolefin with maleic anhydride, with a polyalkylene polyamine. The mono- and bis-forms of the above polyalkyl or polyalkenyl succinimide can be produced by changing the reaction ratio of the polyalkyl or polyalkenyl succinic anhydride and the polyalkylene polyamine. In the production of polyalkyl or polyalkenyl succinimide, the polyolefin used as a raw material is appropriately selected from those obtained by polymerizing α-olefins having about 2 to 8 carbon atoms. Moreover, the alpha olefin which forms polyolefin may be used 1 type, and may be used in combination of 2 or more type. Polybutene is particularly preferable as the polyolefin.
On the other hand, examples of the polyalkylene polyamine include polyethylene polyamine, polypropylene polyamine, and polybutylene polyamine. Among these, polyethylene polyamine is preferable.
Moreover, the boron-treated product of polyalkyl or polyalkenyl succinimide used in the present invention can be produced by a conventional method. The boron content in the boron-treated product is usually in the range of 0.1 to 5% by weight based on the total amount of the boron-containing succinimide, and the preferred content is 1% by weight or more.

  In the lubricating oil composition of the present invention, the boron-containing succinimide used as the component (C) is usually in the range of 0.1 to 10% by weight and in the range of 0.3 to 5% by weight based on the total amount of the composition. Are preferably used. When the compounding amount of the boron-containing succinimide is less than 0.1% by weight, the desired effect is not sufficiently exhibited. On the other hand, even when the compounding amount exceeds 10% by weight, the desired effect is sufficient. Is not demonstrated.

  When the lubricating oil composition of the present invention contains these three types of additives as essential components, when used as a continuously variable transmission oil, a high intermetal friction coefficient required as a continuously variable transmission lubricating oil is obtained. There is a remarkable effect that both the anti-shudder property for the slip control mechanism is achieved.

(3) Other additive components The lubricating oil composition of the present invention comprises the above-mentioned compound as an essential component in a lubricating base oil, and further used in normal ATF as necessary. Various additives such as friction modifiers, ashless dispersants, metal deactivators, antioxidants, viscosity index improvers, pour point depressants, antifoaming agents, corrosion inhibitors, colorants, etc. It can add suitably in the range which does not impair the objective of this invention.

  As the friction modifier, an amine friction modifier, a boron-containing alcohol friction modifier, or the like can be suitably used. In addition, amide compounds, imide compounds, boron-containing cyclic carboxylic acid imides, and the like can also be suitably used. As the amine-based friction modifier, alkylamine, alkyldiamine, dialkylamine, or trialkylamine having 4 to 36 carbon atoms can be used. In particular, alkylamine and dialkylamine can be preferably 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 anti-shudder performance is insufficient. When it exceeds, the friction coefficient between metals will fall.

  Examples of the ashless dispersant include imide compounds such as monoimide and bisimide. 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 oxidation 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.

  As the viscosity index improver, a dispersion-type viscosity index improver can be preferably used, and among them, polymethacrylate is preferable, and it is preferable to include about 5 to 20 mol% of a polar monomer. Examples of the polar monomer include diethylaminoethyl methacrylate, 2 An amine such as -methyl-5-vinylpyridine and a nitrogen compound such as N-vinylpyrrolidinone can be preferably used. As the molecular weight of the dispersion type viscosity index improver, those having a number average molecular weight of 5,000 to 200,000 can be used, but those having an average molecular weight of 100,000 or less can be suitably used from the viewpoint of shear stability. The blending amount of the dispersion-type viscosity index improver is preferably in the range of 1 to 7% by weight based on the total amount of the composition, and if it is less than 1%, the effect of improving oxidation stability is small, whereas if it exceeds 7% Oxidation stability may be deteriorated. As the viscosity index improver, other viscosity index improvers can be used in combination. Viscosity index improvers that can be used are olefin copolymers such as ethylene-propylene copolymers, polyacrylates, polymethacrylates and the like, and polymethacrylates are preferred from the viewpoint of low temperature viscosity. These are usually used in a proportion of 1 to 20% by weight.

  Pour point depressants generally include ethylene-vinyl acetate copolymer, condensate of chlorinated paraffin and naphthalene, condensate of chlorinated paraffin and phenol, polymethacrylate, polyalkylstyrene, etc. Methacrylate is preferably used. These 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.
Furthermore, other additives such as corrosion inhibitors and colorants can be used in the lubricating oil composition of the present invention as desired.

  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. In addition, the lubricating oil composition of the present invention has a performance superior to that of a belt-type CVT having a torque converter with a slip control lockup clutch, but has a lockup clutch without a slip control mechanism. Since it shows stable performance even for friction materials of wet clutches and maintains a high intermetal friction coefficient over a long period of time, it shows excellent performance for general belt type CVT, as belt type CVT oil, It can be preferably used. Furthermore, it can be suitably used as a normal automatic transmission fluid (ATF).

  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 alkyl group linearity measuring method, the intermetallic friction coefficient measuring method, and the evaluation method of shudder prevention performance of the organic acid metal salt in Examples and Comparative Examples were evaluated by the following methods.

(1) Alkyl group linearity An organic acid metal salt was converted into a corresponding organic acid, a ¹³ C-NMR spectrum was measured under the following conditions, and an alkyl group linearity was calculated by the following formula.
Measurement conditions and equipment used: EX400 (manufactured by JEOL Ltd.)
And observation nucleus: ¹³ C
・ Observation frequency: 100.50 MHz
・ Measurement mode: Gated ¹ H decoupling ・ Internal standard: TMS (= 0 ppm)
Relaxation reagent: Cr (acac) ₃
Solvent: CDCl ₃
Sample amount: 300mg
Temperature: 30 ℃

(2) Coefficient of friction between metals Using a SRV friction tester (reciprocating friction tester) as a testing machine, the test was conducted under the following test conditions. ) was measured. It is determined that the higher the friction coefficient between metals, the larger the transmission torque capacity. Those having a coefficient of friction between metals of 0.15 or more were acceptable.
Test conditions / test piece: Ball (SUJ2), plate (SUJ2)
- test temperature: 100 ℃
· Load: 100N
- Frequency: 50Hz
Stroke: 1mm

(3) Anti-shudder performance The test method for anti-shudder performance was in accordance with JASO M349-98 automatic transmission oil shudder prevention performance test method. As the friction material, a friction plate (friction material: D-0512) and a steel plate specified in JASO M349-98 were used.

(4) Examples and comparative examples
[Example 1 (reference example)]
As a lubricating base oil, a solvent-refined paraffinic mineral oil (kinematic viscosity at 100 ° C., 4 mm ² / s) is used. , (B) component phosphorus wear inhibitor 350 ppm as P amount, (C) component boron-containing succinimide 1.0 wt%, and other additives as antioxidant, viscosity index improver, metal A lubricating oil composition was prepared by blending a total amount of 10.0% by weight of each constant amount of the deactivator and antifoaming agent. A detailed description of the blended additive is as follows.
The component (A) Ca salicylate has an average alkyl group carbon number of 20 per salicylic acid group, an alkyl group linearity of 47.3%, and a total base number of 170 mgKOH / g.
The phosphorus antiwear agent as component (B) is a mixture of monoalkyl acid phosphate and dialkyl acid phosphate having an alkyl group having 4 carbon atoms.
The boron-containing succinimide as component (C) is a boron-containing polybutenyl succinimide having a molecular weight (MW) of 1600, and the weight ratio of boron is 4.7% by weight based on the weight of all active ingredients. .
About this prepared lubricating oil composition, the measurement of the friction coefficient between metals and evaluation of the anti-shudder performance were implemented. These results are shown in Table 1. The friction coefficient between metals of Example 1 is 0.175, and the anti-shudder performance, that is, dμ / dv is positive and good.

[Example 2-5]
In the same manner as in Example 1, the lubricating base oil component and the additive component shown in Table 1 were blended in the proportions shown in the same table to prepare a lubricating oil composition. About this prepared lubricating oil composition, the measurement of the friction coefficient between metals and evaluation of the anti-shudder performance were implemented. These results are shown in Table 1. Similar to Example 1, the evaluation results of Examples 2 to 5 are good.

[Comparative Example 1-5]
A lubricating oil composition was prepared by blending the lubricating base oil component shown in Table 2 and various additive components in the proportions shown in the same table. About this prepared lubricating oil composition, the measurement of the friction coefficient between metals and evaluation of the anti-shudder performance were implemented. These results are shown in Table 2.

[Examples 6 and 7 (6 and 7 are reference examples), Comparative Example 6]
A lubricating oil composition was prepared by blending the lubricating base oil component and various additive components shown in Table 3 in the proportions shown in the same table. About this prepared lubricating oil composition, the measurement of the friction coefficient between metals and evaluation of the anti-shudder performance were implemented. These results are shown in Table 3.

From the above Examples and Comparative Examples, each specific amount of three types of additives, organic acid metal salt (A), antiwear agent (B), and boron-containing succinimide (C), which are essential components in the present invention. It has been clarified that, by blending, in any of the examples, the quality of the continuously variable transmission lubricant can be satisfied and high quality can be obtained.
On the other hand, in the comparative example 1 which does not mix | blend the organic acid metal salt of (A) component, the friction coefficient between metals is low and a shudder prevention performance is also disqualified. Similarly, in the comparative example 2 which does not mix | blend the anti-wear agent of (B) component, the friction coefficient between metals is low. In Comparative Example 3 in which the boron-containing succinimide (C) component is not blended, the friction coefficient between metals is low. In Comparative Example 4 where the linearity of the alkyl group of the organic acid metal salt is lower than 25%, the anti-shudder property is insufficient, and in order to satisfy the anti-shudder property of Comparative Example 4, an amine friction modifier is blended. In Comparative Example 5, the coefficient of friction between metals is low. From the results of Examples 3 to 5, as the alkyl group linearity of the organic acid metal salt increases, the intermetallic friction coefficient decreases. When the alkyl group linearity is too large, the intermetallic friction coefficient is This suggests a shortage. On the other hand, when Example 1, Example 6, and Comparative Example 6 are seen, when the weight of the boron in the active ingredient of a boron containing succinimide falls, it turns out that the friction coefficient between metals is falling.

Claims (3)

Lubricating oil composition for an automatic transmission comprising a lubricating base oil composed of mineral oil and / or synthetic oil and an organic acid metal salt (A), an antiwear agent (B), and a boron-containing succinimide (C). The organic acid metal salt (A) is a sulfonate or phenate of Ca, Mg or Ba having at least one chain hydrocarbon group, and is determined by carbon nuclear magnetic resonance ( ¹³ C-NMR) measurement. Further, the push belt type is characterized in that the linearity of the alkyl group in the chain hydrocarbon group is 25 to 60%, and the antiwear agent (B) is an acidic phosphate ester or zinc dialkyldithiophosphate. Lubricating oil composition for continuously variable transmission.   2. The lubricating oil composition for a push belt type continuously variable transmission according to claim 1, wherein the compounding amount of the organic acid metal salt (A) is 100 to 1000 ppm as a metal amount based on the total amount of the composition.   The lubricating oil composition for a push belt type continuously variable transmission according to claim 1, wherein the continuously variable transmission is a push belt type having a torque converter with a lock-up clutch.