JPH09202890A - Lubricating oil composition for automatic transmission - Google Patents

Abstract

(57) Abstract: In an automatic transmission for a vehicle equipped with a slip control mechanism, an automatic transmission having a high shudder vibration prevention performance and a sufficient transmission torque capacity even when a lockup mechanism is operated in a low speed range. To provide a lubricating oil composition for machines. SOLUTION: The base oil has a general formula: (In the above general formula [I], R ¹ and R ² may be the same or different from each other, each is a hydrocarbon group having 5 or more carbon atoms, and R ³ is a hydrocarbon group having 1 to 5 carbon atoms. , R ⁴ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may have an amino group and / or an amide bond, and n is an integer of 0 to 10.) There is provided a lubricating oil composition for an automatic transmission, which comprises a compound represented by:

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil composition for an automatic transmission, and more particularly, to an automatic transmission having a high transmission torque capacity and excellent anti-shudder vibration performance, and particularly a slip control mechanism. The present invention relates to a suitable lubricating oil composition.

[0002]

2. Description of the Related Art An automatic transmission is composed of a torque converter, a wet multi-plate clutch, a gear bearing mechanism and a hydraulic control mechanism for controlling these, and a transmission torque capacity is automatically set according to the vehicle speed and the size of load. It has a mechanism that

Lubricating oil for automatic transmission (ATF) is commonly used in all of these mechanisms in such an automatic transmission, and in order to operate the automatic transmission smoothly, a torque converter and It is required that the hydraulic control mechanism functions as a power transmission medium, the gear bearing mechanism functions as lubricating oil, and the hydraulic control mechanism functions as hydraulic oil.

Further, in recent years, many automobile automatic transmissions have a lock-up clutch built in the torque converter which is effective for improving the fuel consumption rate. The function of the lock-up clutch is to transfer the driving force of the engine directly to the transmission according to the driving conditions, and improve the efficiency of the torque converter by switching the torque converter drive and the direct drive at an appropriate time. be able to.

However, since the conventional lock-up mechanism operates only in the high speed range and not in the low speed range, in the low speed range such as when the vehicle is started, the engine output speed during torque transmission by the torque converter. Between the engine and the transmission input rotation speed caused a power transmission loss, which was a cause of deterioration of the fuel consumption rate. In order to reduce the power transmission loss and improve the fuel consumption rate, a slip control system has recently been introduced which operates the lockup mechanism even in the low speed range of the automatic transmission.

However, when the drop-up mechanism is operated in the low speed range, a problem that an abnormal vibration of the vehicle body called a shudder frequently occurs on the friction surface of the lock-up clutch occurs. In particular, in a slip control type lock-up clutch, shudder is more likely to occur when the friction coefficient decreases as the sliding speed increases, so μ (friction coefficient increases as the sliding speed increases. Coefficient) -V (sliding speed) characteristics are improved, and lubricating oil for automatic transmissions having excellent anti-shudder vibration performance is required.

Conventionally, lubricating oils for automatic transmissions include amides, carboxylic acids, in addition to phosphate esters as friction modifiers.
Although it has been proposed to use amine or the like, such a friction modifier has a drawback that the friction coefficient of the lock-up clutch portion is lowered and the transmission torque capacity is insufficient. A lubricating oil for an automatic transmission having both prevention performance and transmission torque capacity has been demanded, and its technical development has been strongly desired.

[0008]

SUMMARY OF THE INVENTION Therefore, in view of the above-mentioned development situation of the lubricating oil for an automatic transmission, the present invention provides a lubrication for an automatic transmission which is excellent in the anti-shudder vibration performance without impairing the transmission torque capacity. An object is to provide an oil composition.

[0009]

Means for Solving the Problems Accordingly, the present inventors have:
As a result of intensive research aimed at providing a lubricating oil composition for an automatic transmission with improved anti-shudder vibration performance without lowering the transmission torque capacity, as a result, the lubricating base oil will be described in detail below. However, since the lubricating oil composition obtained by containing an effective amount of a specific imide compound as an essential component has the lubricating characteristics required as a lubricating oil for an automatic transmission, the transmission torque capacity and the anti-shudder vibration performance, The inventors have found that the above problems can be solved, and have completed the present invention based on these findings.

Thus, according to the present invention, the lubricating base oil has the following general formula [I]:

[0011]

Embedded image (In the above general formula [I], R ¹ and R ² may be the same or different from each other, and each has 5 carbon atoms.
The above hydrocarbon groups, R ³ is a divalent hydrocarbon group having 1 to 5 carbon atoms, and R ⁴ is a hydrogen atom or 1 to 2 carbon atoms.
It is a hydrocarbon group of 0, and n is an integer of 0-10. )
The present invention provides a lubricating oil composition for an automatic transmission, which comprises an effective amount of a compound represented by

According to the present invention, the following (1) to (1
As shown in 1), in a preferred embodiment, (1) the lubricating base oil, based on the total weight of the composition, represented by the general formula [I]

[0013]

Embedded image (In the above general formula [I], R ¹ and R ² may be the same or different from each other, and each has 5 carbon atoms.
The above hydrocarbon groups, R ³ is a divalent hydrocarbon group having 1 to 5 carbon atoms, and R ⁴ is a hydrogen atom or 1 to 2 carbon atoms.
It is a hydrocarbon group of 0, and n is an integer of 0-10. )
A lubricating oil composition for an automatic transmission, containing 0.02% to 4% by weight of a compound represented by: (2) a lubricating base oil, based on the total weight of the composition, a general formula [I]

[0014]

Embedded image (In the above general formula [I], R ¹ and R ² may be the same or different from each other, and each has 5 carbon atoms.
To 40 hydrocarbon groups, R ³ is a divalent hydrocarbon group having 1 to 5 carbon atoms, and R ⁴ is a hydrogen atom or 1 to 1 carbon atoms.
20 hydrocarbon groups, which may have an amino group and / or an amide bond, and n is an integer of 1-10. ) 0.02% by weight to the compound represented by 4
A lubricating oil composition for an automatic transmission, which comprises 3% by weight, (3) a lubricating base oil, based on the total weight of the composition, (a) a general formula [I]

[0015]

Embedded image (In the above general formula [I], R ¹ and R ² may be the same or different from each other, and each has 5 carbon atoms.
To 40 hydrocarbon groups, R ³ is a divalent hydrocarbon group having 1 to 5 carbon atoms, and R ⁴ is a hydrogen atom or 1 to 1 carbon atoms.
20 hydrocarbon groups, which may have an amino group and / or an amide bond, and n is an integer of 1 to 5. 0.02 wt% to 4 wt% of a compound represented by the formula (b) and (b) 0.02 wt% to 5 wt% of at least one organic acid metal salt selected from the group consisting of sulfonate, phenate, salicylate and phosphonate.
A lubricating oil composition for an automatic transmission, containing (4) a lubricating base oil, based on the total weight of the composition: (a) General formula [I]

[0016]

[Chemical 6] (In the above general formula [I], R ¹ and R ² may be the same or different from each other, and each has 5 carbon atoms.
To 40 hydrocarbon groups, R ³ is a divalent hydrocarbon group having 1 to 5 carbon atoms, and R ⁴ is a hydrogen atom or 1 to 1 carbon atoms.
It is a hydrocarbon group of 20 and n is an integer of 0-10. ) A compound represented by 0.02% to 4% by weight,
(B) 0.02 wt% to 5 wt% of at least one organic acid metal salt selected from the group consisting of sulfonates, phenates, salicylates and phosphonates, and (c) phosphates, acid phosphates, phosphites. And at least one compound selected from the group consisting of acidic phosphite and 0.01 wt% to 5 wt% of the lubricating oil composition for automatic transmission, (5) lubricating base oil, generally Formula [I]

[0017]

Embedded image (In the above general formula [I], R ¹ and R ² may be the same or different from each other, and each has 8 to 2 carbon atoms.
5 is a straight chain hydrocarbon group having no branching, R ³ is a divalent hydrocarbon group having 2 to 5 carbon atoms, and R ⁴ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. , N is 0 to 1
It is an integer of 0. ) A lubricating oil composition for an automatic transmission, containing a compound represented by the formula (6), (6) a lubricating base oil, based on the total weight of the composition, (a) a general formula [I]

[0018]

Embedded image (In the above general formula [I], R ¹ and R ² may be the same or different from each other and each has 8 carbon atoms.
A straight chain hydrocarbon group having no branching of 25 to R ³
Is a divalent hydrocarbon group having 2 to 5 carbon atoms, R ⁴ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and n is 0.
Is an integer of 10 to 10. 0.02 wt% to 2 wt% of a compound represented by the formula (b) and (b) 0.02 wt% of at least one organic acid metal salt selected from the group consisting of sulfonates, phenates, salicylates and phosphonates.
A lubricating oil composition for an automatic transmission, containing (a) the general formula [I], based on the total weight of the composition.

[0019]

Embedded image (In the above general formula [I], R ¹ and R ² may be the same or different from each other and each has 8 carbon atoms.
A straight chain hydrocarbon group having no branching of 25 to R ³
Is a divalent hydrocarbon group having 2 to 5 carbon atoms, R ⁴ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and n is 0.
Is an integer of 10 to 10. 0.02 wt% to 2 wt% of a compound represented by the formula (b), (b) 0.02 wt% to 5 wt% of at least one organic acid metal salt selected from the group consisting of sulfonates, phenates, salicylates and phosphonates; (C) at least one compound 0.01 selected from the group consisting of phosphoric acid ester, acidic phosphoric acid ester, phosphorous acid ester and acidic phosphorous acid ester
A lubricating oil composition for an automatic transmission, which contains 5% by weight to 5% by weight, (8) a lubricating base oil having the general formula [II]

[0020]

Embedded image (In the general formula [II], R ¹ and R ² may be the same or different from each other, and have 8 to ² carbon atoms.
5 is a straight chain hydrocarbon group having no branch, and n is 1 to
It is an integer of 5. ) A lubricating oil composition for an automatic transmission, containing an imide compound represented by the formula (9), (9) a lubricating base oil, based on the total weight of the composition, (a) a general formula [II]

[0021]

Embedded image (In the general formula [II], R ¹ and R ² may be the same or different from each other, and have 8 to ² carbon atoms.
5 is a straight chain hydrocarbon group having no branch, and n is 1 to
It is an integer of 5. ) Imide-based compound represented by 0.02
% To 4% by weight and (b) 0.02% to 5% by weight of at least one organic acid metal salt selected from the group consisting of sulfonates, phenates, salicylates and phosphonates, lubrication for automatic transmissions. Oil composition, (10) Lubricating base oil, based on the total weight of the composition, (a) General formula [II]

[0022]

Embedded image (In the general formula [II], R ¹ and R ² may be the same or different from each other, and have 8 to ² carbon atoms.
5 is a straight chain hydrocarbon group having no branch, and n is 1 to
It is an integer of 5. ) Imide-based compound represented by 0.02
% To 4% by weight, (b) sulfonate, phenate,
0.02% by weight of at least one organic acid metal salt selected from the group consisting of salicylates and phosphonates
% By weight and (c) at least one compound selected from the group consisting of phosphoric acid ester, acidic phosphoric acid ester, phosphorous acid ester and acidic phosphorous acid ester 0.0
1% to 5% by weight of lubricating oil composition for automatic transmission or (11) the lubricating base oil, the compound represented by the general formula [I] and the organic acid metal salt and / or A phosphorus compound is further contained, and further, an antiwear agent, a viscosity index improver, an ashless dispersant, an antioxidant, a metal deactivator, a corrosion inhibitor, an antifoaming agent, and other lubricating oil composition for automatic transmission. It is possible to provide a lubricating oil composition for an automatic transmission, which contains at least one kind of additive selected from the group consisting of necessary additives.

The specificity of the present invention provides a novel compound characterized in that R ¹ and R ² of the imide compound represented by the general formula [I] are each a hydrocarbon group having 5 or more carbon atoms. The present invention is based on this, and as an operation effect that cannot be recognized in the past, the present invention focuses on the fact that the shudder vibration prevention performance can be improved without reducing the transmission torque capacity of the automatic transmission lubricating oil.

The present invention will be described in detail below.

The base oil of the lubricating oil composition for an automatic transmission of the present invention is not particularly limited, and those commonly used as lubricating base oils can be adopted.
Both mineral oils and synthetic oils can be used.

As the mineral base oil, a lubricating oil raw material derived from atmospheric distillation and vacuum distillation of crude oil is phenol,
Furfural, a solvent-refined raffinate obtained by treating with an aromatic extraction solvent such as N-methylpyrrolidone, and hydrogenation obtained by contacting a lubricating oil raw material with hydrogen under hydrotreatment conditions in the presence of a hydrotreating catalyst. It is possible to use a treated oil, an isomerized oil obtained by contacting a wax with hydrogen under isomerization conditions in the presence of an isomerization catalyst, or an oil mixture thereof. Lubricating oil bases can usually be produced by arbitrarily combining solvent refining step, hydrotreating step, isomerizing step, etc., but by any production method, dewaxing step, hydrofinishing step, clay A process such as a treatment process can be arbitrarily adopted. Specific examples of the mineral oil-based mixed base material include light neutral oil, medium neutral oil, and heavy neutral oil bright stock.

The synthetic base oil is, for example, poly α-olefin, α-olefin copolymer, polybutene, alkylbenzene, polyol ester, dibasic acid ester, polyoxyalkylene glycol, polyoxyalkylene glycol ester or polyoxyalkylene. Examples thereof include glycol ether and silicone oil.

In order to satisfy the required quality including the kinematic viscosity required for the lubricating oil for the automatic transmission, the mixed base material of the lubricating base oil as described above is used alone or in two or more kinds, for example in two or more kinds of mineral oil or By appropriately mixing mineral oil and synthetic oil,
The desired lubricating base oil can be prepared. The lubricating base oil of the present invention is usually 2 mm ^{2 at} 100 ° C.
/ S to ²⁰ mm ² / s, preferably 3 mm ² / s to 1
Those having a kinematic viscosity in the range of 5 mm ² / s can be used. If the viscosity of the lubricating base oil is too high, its low temperature viscosity properties will deteriorate, and conversely, if the viscosity is too low, wear may increase in the sliding parts such as the gear bearings and clutches of the automatic transmission. .

The friction modifier used in the lubricating oil composition for an automatic transmission of the present invention has the following general formula [I]:

[0030]

Embedded image It is an imide compound represented by.

In the above general formula [I], R ¹ and R ² may be the same or different and each is a saturated or unsaturated hydrocarbon group having 5 or more carbon atoms, preferably 5 to 40 carbon atoms. . As the hydrocarbon group, for example, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, oleyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, In addition to the nonadecyl group and the like, hydrocarbon groups having up to 40 carbon atoms can be exemplified. Particularly preferable hydrocarbon groups include linear hydrocarbon groups having 8 to 25 carbon atoms.
When the number of carbon atoms in the hydrocarbon group is 4 or less, the anti-shudder vibration performance is deteriorated, and a lubricating oil composition having sufficient practical value as a lubricating oil for an automatic transmission cannot be provided.

In the above general formula [I], R ³ is a divalent hydrocarbon group having 1 to 5 carbon atoms, preferably an alkylene group having 2 to 3 carbon atoms.

In the above general formula [I], R ⁴ is a hydrogen atom or a carbon atom number of 1 to 20, preferably a hydrogen atom or 1
And 10 to 10 hydrocarbon groups. As the hydrocarbon group, an alkyl group having 1 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; a cycloalkyl group having 6 to 20 carbon atoms; 6 to 2 carbon atoms
0 aryl group may be mentioned, and the aryl group may have 1 to 12 alkyl groups. Particularly, a hydrogen atom or an alkyl group having 1 to 10 carbon atoms is preferable. As the above-mentioned hydrocarbon group, those having an amino group or an amide bond and several of them, that is, 1 to 5 each, in the structure can also be used.

[0034] And can be bonded to the carbon atom of the hydrocarbon group at any position.

In the above general formula [I], n is 1 to 1
It is an integer of 0, preferably 1-5.

According to the present invention, the compound represented by the following general formula [II] is particularly preferable.

[0037]

Embedded image In the general formula [II], R ¹ and R ² are each
It is a linear hydrocarbon group having 8 to 25 carbon atoms, and n is 1 to 5
It is.

The imide compound of the present invention is added in an effective amount to the base oil of the lubricating oil composition for automatic transmission. The effective amount of the imide compound varies depending on the properties of the base oil, but is 0.02 to 4% by weight, preferably 0.03 to 3% by weight based on the total weight of the composition.

The imide compound represented by the above general formula [I] can be synthesized by reacting a hydrocarbon-substituted succinic anhydride with a polyamine. Examples of polyamines include monodiamines such as ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, and polyalkylenepolyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and the like.

The lubricating oil composition for an automatic transmission of the present invention contains the imide compound represented by the above-mentioned general formula [I] as an essential component to reduce the transmission torque capacity when used as an automatic transmission oil. Without this, the anti-shudder vibration is improved, and in particular, the anti-shudder vibration of the automatic transmission with the slip control mechanism is effectively prevented.
Furthermore, by adding an organic acid metal salt and / or the above-mentioned phosphorus compound and combining the imide compounds,
The anti-shudder vibration performance can be further improved.

The organic acid metal salts include sulfonates, phenates, salicylates and phosphonates, and the metal components of the organic acid metal salts are preferably alkaline earth metals, such as calcium, magnesium,
Examples include barium. Specifically, calcium sulfonate, phenate, salicylate and phosphonate, magnesium sulfonate, phenate, salicylate and phosphonate can be used. Sulfonates, phenates, salicylates and phosphonates have a hydrocarbon group, and at least one is preferably a relatively long chain having 6 or more carbon atoms. For example, a linear or branched alkyl group having 6 to 18 carbon atoms; a linear or branched alkenyl group having 6 to 18 carbon atoms;
A cycloalkyl group having 18 to 18 carbon atoms; an aryl group having 6 to 18 carbon atoms and the like can be used, and the aryl group has an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms as a substituent. Good. Among the above hydrocarbon groups, a preferred hydrocarbon group is an alkyl group having 6 to 18 carbon atoms, and an alkyl group having 8 to 12 carbon atoms is particularly preferable from the viewpoint of improving the transmission torque capacity. Specific examples of the sulfonate include alkylbenzene sulfonates such as hexylbenzene sulfonate, hexadecyl toluene sulfonate, hexadecyl xylene sulfonate, octadecyl benzene sulfonate, dodecyl benzene sulfonate, and the like. Calcium and magnesium are preferred as components. Further, salicylate is particularly preferably one having 10 to 14 carbon atoms, and specific examples thereof include dodecyl salicylate. Calcium and magnesium are preferable as the metal component. The phenate is preferably a metal salt of alkylphenol,
For example, dodecylphenol calcium salt and the like can be mentioned. The phosphonate is a metal salt of phosphonic acid or thiophosphonic acid obtained by the reaction of polyolefin and phosphorus pentasulfide, and calcium or magnesium is used as the metal component. These organic acid metal salts preferably have a total base number of 10 mgKOH / g to 400 mgKOH / g.

The organic acid metal salt of sulfonate, phenate, salicylate and phosphonate is 0.02% to 5% by weight, preferably, based on the total weight of the composition.
It is effective to add it in the range of 0.1% by weight to 2% by weight.

Examples of the phosphorus compounds include phosphoric acid ester, acidic phosphoric acid ester, phosphorous acid ester, acidic phosphorous acid ester, zinc thiophosphate, etc., and they are represented by the general formulas [III] and [IV]. And those represented by [V].

[0044]

Embedded image

[0045]

Embedded image

[0046]

Embedded image In the above general formulas [III] to [V], R ⁵ is a hydrocarbon group having 1 to 30 carbon atoms or a sulfur atom-containing hydrocarbon group, and may be the same or different in each formula. x is 1, 2 or 3 and y is 1 or 2. Preferred hydrocarbon groups are alkyl groups having 1 to 30 carbon atoms; alkenyl groups having 2 to 30 carbon atoms; cycloalkyl groups having 6 to 30 carbon atoms; aryl groups having 6 to 30 carbon atoms, alkylaryl groups, and arylalkyl groups. Is. A particularly suitable hydrocarbon group is a linear or branched alkyl group having 3 to 24 carbon atoms.

Specific examples of the phosphoric acid ester include triaryl phosphate and the like. Examples thereof include benzyl diphenyl phosphate, allyl diphenyl phosphate, and the like.
Triphenyl phosphate, tricresyl phosphate, ethyl diphenyl phosphate, tributyl phosphate, dibutyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, ethyl phenyl diphenyl phosphate, diethyl phenyl phenyl phosphate, propyl phenyl diphenyl phosphate, dipropyl phenyl phenyl phosphate,
Compounds such as triethylphenyl phosphate, tripropylphenyl phosphate, butylphenyldiphenylphosphate, dibutylphenylphenylphosphate, tributylphenylphosphate, propylphenylphenylphosphate mixture, butylphenylphenylphosphate mixture and the like can be mentioned. Of these compounds, phosphate having an alkyl group having 3 to 10 carbon atoms is preferable.

Examples of the acidic phosphoric acid ester include monobutyl phosphate, monohexyl phosphate, monooctyl phosphate, monolauryl phosphate,
Examples include monophenyl phosphate, dibutyl phosphate, dioctyl phosphate, di (2-ethylhexyl) phosphate, didecyl phosphate, dilauryl phosphate, dioleyl phosphate, distearyl phosphate, diphenyl phosphate and the like. Of these, mono- or dialkyl phosphates having an alkyl group with 3 to 10 carbon atoms or a mixture thereof are preferable.

Examples of the phosphite include triphenylphosphite, tri (p-cresyl) phosphite, tris (nonylphenyl) phosphite, trioctyltrithiophosphite, triisooctylphosphite, diphenylisodecylphosphite. Examples include phyto, phenylisodecyl phosphite, triisodecyl phosphite, tristearyl phosphite, trioleyl phosphite, and the like. Examples of the acidic phosphite include di-2-ethylhexyl hydrogen phosphite, dilauryl hydrogen phosphite,
Examples thereof include dioleylhydrogen phosphite.

Examples of the sulfur atom-containing hydrocarbon group include dodecylthioethyl group.

The above phosphorus compound is added to the base oil in a proportion of 0.01% to 5% by weight, preferably 0.03% to 3% by weight, based on the total weight of the composition. . A particularly preferred amount of addition is in the range of 0.05% by weight to 1% by weight.

Further, the lubricating oil composition for an automatic transmission of the present invention may optionally contain other additives such as other friction modifiers, antiwear agents, viscosity index improvers, ashless dispersants, and An antioxidant, an extreme pressure agent, a metal deactivator, a pour point depressant, a defoaming agent, a corrosion inhibitor and the like can be added as appropriate.

As the viscosity index improver, for example, polymethacrylate type, polyisobutylene type, ethylene-propylene copolymer type, styrene-butadiene hydrogenated copolymer and the like can be used, and these are 3% by weight to 35% by weight. Used in percentage by weight.

As the ashless dispersant, for example, polybutenyl succinimide type, polybutenyl succinimide type,
There are benzylamine type and succinate type,
These are used in a proportion of 0.05% to 7% by weight.

Examples of the antioxidant include amine antioxidants such as alkylated diphenylamine, phenyl-α-naphthylamine and alkylated phenyl-α-naphthylamine, 2,6-di-tert-butylphenol,
Phenol-based antioxidants such as 4,4′-methylenebis- (2,6-di-tertiary-butylphenol) and zinc dithiophosphate can be mentioned. These are 0.05% by weight to 5% by weight. Used in proportion.

Examples of extreme pressure agents include dibenzyl sulfide and dibutyl disulfide, which are used in a proportion of 0.05% by weight to 3% by weight.

Examples of the metal deactivator include benzotriazole, thiadiazole and the like.
It is used in a proportion of 0.01 to 3% by weight.

Examples of the pour point depressant include ethylene-vinyl acetate copolymer, condensate of chlorinated paraffin and naphthalene, condensate of chlorinated paraffin and phenol, polymethacrylate, polyalkylstyrene and the like. , These are used in a proportion of 0.1% to 10% by weight. Further, a corrosion inhibitor, an antifoaming agent, etc. may be used as long as the object of the present invention is not impaired.

The contents of the above various additives are as follows.

Content (% by weight) Preferred content (% by weight) Viscosity index improver 3 to 35 4 to 30 Ashless dispersant 0.05 to 7 0.1 to 5 Antioxidant 0.05 to 5 0.1 to 3 Extreme pressure agent 0.05 to 3 0.1 to 2 Metal deactivator 0.01 to 3 0.01 to 2 Pour point depressant 0.1 to 10 0.5 to 8 Corrosion inhibitor 0.01 to 5 Defoaming agent 0.0001 to 1

[0061]

BEST MODE FOR CARRYING OUT THE INVENTION One mode of carrying out the lubricating oil composition for an automatic transmission according to the present invention is as follows. Using solvent-refined paraffinic mineral oil having a kinematic viscosity at 100 ° C. of 4 mm ² / s as a base oil, based on the total weight of the composition: 0.5 to 2% by weight of imide compound (Compound A) Organic metal salt (calcium sulfonate) 0.1 -0.5 wt% -Phosphorus compound (trialkyl phosphate) 0.1-0.5 wt% -Polymethacrylate 2-10 wt% -Polybutenyl succinimide 2-5 wt% -2,6-di-t-butyl-4 -A lubricating oil composition for an automatic transmission, which comprises 0.2 to 1% by weight of methylphenol and 0.02 to 0.1% by weight of benzotriazole is provided.

[0062]

EXAMPLES The present invention will be described more specifically below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and the like.

The shudder vibration prevention performance and the transmission torque capacity were evaluated by the following measuring methods. (1) Shader vibration prevention performance As a testing machine, LVFA (Low Velocity F)
(Rection Apparatus) is used to measure μ _H and μ _L under the following experimental conditions, and the μ _H / μ _L ratio is calculated.

Experimental conditions・ Friction material: SD-1777 ・ Amount of oil: 100 cc ・ Oil temperature: 80 ° C. ・ Surface pressure: 10 kgf / cm ² µ _H ... Friction coefficient at relative slip speed 1.5 m / s µ _L・..The friction coefficient μ _H / μ _L ratio at a relative slip speed of 0.5 m / s is used as the shudder vibration prevention performance index, and is used as the criterion for judging the shudder vibration prevention effect. If the μ _H / μ _L ratio (shudder vibration prevention performance index)> 1, then no shudder occurs in the actual machine. (2) Transmission torque capacity SAE No. 2 Using a friction tester, a Dynamic test and a Static test are performed under the following conditions.

・ Friction material: SD-1777, 3 sheets ・ Oil amount: 800 cc ・ Oil temperature: 100 ° C. ・ Surface pressure: 8 kgf / cm ² [Dynamic test] Friction material rotation speed 3600 rp
m, inertia weight of 3.5 kgf · cm · s ² , rotate without load, apply pressure so that the friction material is sandwiched between steel plates, and stop rotation. [Static test] A pressure is applied so that the friction material is sandwiched between steel plates, the friction material is rotated at a rotation speed of 0.72 rpm, and the rotational torque generated at that time is read and converted into a friction coefficient. The coefficient of static friction μs at the time of the maximum torque that starts sliding at low speed rotation is measured.

The transmission torque capacity was evaluated by SAE No. 2
The coefficient of static friction μs in the test 100c / c was used.
It is evaluated that the transmission torque capacity increases as μs exceeds 0.100.

Example 1 Solvent-refined paraffinic mineral oil (100 ° C.) was used as a lubricating base oil.
Kinematic viscosity at 4 mm ² / s), 1.0% by weight of imide compound (Compound A), 0.3% by weight of calcium sulfonate (total base number 300 mgKOH / g), 0.2% by weight of tributyl phosphate. , Polymethacrylate (viscosity index improver) 5.0% by weight, polyisobutenyl succinimide (ashless dispersant) 4.0% by weight, 2.6-
Di-t-butyl-4-methylphenol (antioxidant)
A lubricating oil composition containing 0.4 wt% and benzotriazole (metal deactivator) 0.05 wt% was prepared.
The compound A used here has, as shown in Table 4, R ¹ and R ² are each a linear alkyl group having 12 carbon atoms, R ³ is an alkylene group having 2 carbon atoms, and R ⁴ is a hydrogen atom. n is 2
Is an imide compound. The following results were obtained by measuring the anti-shudder vibration performance and the transmission torque capacity of the obtained lubricating oil composition.

Shader vibration prevention performance index (μ _H / μ _L ratio in LVFA): 1.06 Transmission torque capacity (SAE No. 2 test 100c /
Static friction coefficient in c): 0.146 According to the above evaluation results, the shudder vibration prevention performance index 1.06 exceeds 1.00, and the transmission torque capacity 0.146 becomes 0.100. From this, it is understood that the power transmission performance is extremely excellent.

Example 2 As a lubricating base oil, an α-olefin copolymer synthetic oil (kinematic viscosity at 100 ° C .: 4 mm ² / s [SHF manufactured by Mobil Oil Co., Ltd., was used instead of the solvent refined paraffinic mineral oil.
41]) was used and a lubricating oil composition was prepared in the same manner as in Example 1. The shudder vibration prevention performance index and the transmission torque capacity were measured, and the results are shown in Table 1. Substantially equivalent results were obtained compared to mineral base oils.

Examples 3 to 9 Compound A and various additives were added to the base oil shown in Table 1 at the ratios shown in the table to prepare lubricating oil compositions. In particular, as the phosphorus-based compound, tributyl phosphate (Example 3), tricresyl phosphate (Example 4), trioctyl trithiophosphate (Example 5), a mixture of monooctyl phosphate and dioctyl phosphate (1: 1) ( Example 6) was used. The anti-shudder vibration prevention performance and the transmission torque capacity of each of the obtained lubricating oil compositions were determined, and the results shown in Table 1 were obtained.

Example 10 A lubricating oil composition was prepared in the same manner as in Example 1 except that the compound B shown in Table 4 was used instead of the compound A as the imide compound. Compound B is a linear alkyl group having 12 carbon atoms in R ¹ and R ² , R ³ is an ethylene group, R ⁴ is an alkyl group having 6 carbon atoms, and —NH
It is an imide compound in which _two groups are bonded and three NH3 are bonded. Also, n is 2. The lubricating oil composition was subjected to performance evaluation and the results shown in Table 2 were obtained. The shudder vibration prevention performance index (μ _H / μ _L ratio) was 1.07, and the transmission torque capacity (μs) was 0.146, and extremely good results were obtained.

Example 11 A lubricating oil composition was obtained under the same conditions and operations as in Example 1, except that Compound C was used instead of Compound A as the imide compound. In Compound C, as shown in Table 4, R ¹ and R ² are each a linear alkyl group having 18 carbon atoms, R ³ is an ethylene group, R ⁴ is a hydrogen atom, and n
Is the imide compound of 2. Table 2 shows the measurement results of the shudder vibration prevention performance index (μ _H / μ _L ratio) and the transmission torque capacity (μs) of the lubricating oil composition.

Examples 12 to 14 Instead of the compound A as the imide compound, the compound D (Example 12), the compound E (Example 13) and the compound F are used.
A lubricating oil composition was prepared in the same manner as in Example 1 except that (Example 14) was used.

As shown in Table 4, in the compound D, each of R ¹ and R ² is a linear alkyl group having 18 carbon atoms. It is a C10 alkyl group having one group (-NH-), and n is an imide compound.

Compound E is an imide compound in which R ¹ and R ² are each a linear alkyl group having 24 carbon atoms, R ³ is an ethylene group, R ⁴ is a hydrogen atom, and n is 2.

Compound F is an imide compound in which R ¹ and R ² are each a linear alkyl group having 8 carbon atoms, R ³ is an ethylene group, R ⁴ is a hydrogen atom, and n is 2.

Examples 15 to 16 As an imide compound, instead of compound A, compound G
A lubricating oil composition was prepared in the same manner as in Example 1 except that (Example 15) and Compound H (Example 16) were used. Compounds G and H have R ¹ as shown in Table 4.
And R ² are imide compounds each having a linear unsaturated hydrocarbon group. The evaluation results are shown in Table 2.

Comparative Examples 1 to 14 Lubricating oil compositions were prepared by mixing the base oil shown in Table 3 and various additives in the proportions shown in the same table. The shudder vibration prevention performance index (μ _H / μ _L ratio) and transmission torque capacity were determined for each composition, and the results are shown in Table 3.

In the compound I used in Comparative Example 12, R ¹ and R ² are each an n-butyl group having 4 carbon atoms, R ³ is an ethylene group, R ⁴ is a hydrogen atom, and n is 2 Is an imide compound.

In the compound J of Comparative Example 14, R ¹ has ¹ carbon atom.
2 is a linear alkyl group, whereas R ² is a cyclic hydrocarbon group and is an imide compound containing a hydrocarbon group which is not a linear saturated hydrocarbon group.

From the above Examples and Comparative Examples, it became clear that the use of the novel imide compound according to the present invention can satisfy both the anti-shudder vibration prevention performance and the transmission torque capacity. In Comparative Example 12, the compound I is used as the imide compound, and R ¹ and R ² thereof are each an n-butyl group having 4 carbon atoms and do not correspond to the hydrocarbon group having 5 or more carbon atoms of the present invention. It is a thing. Further, in Comparative Example 13, as the ashless detergent dispersant, polyisobutenyl succinimide was added by 6% by weight, which was increased by 2% by weight as compared with the other Examples and Comparative Examples.
The polyisobutenyl succinimide used here has a polyisobutenyl group different from the straight-chain hydrocarbon group having 5 or more carbon atoms and having no branch of the present invention, and the improvement of the anti-shudder vibration performance is improved. I can't see it.

The anti-shudder vibration preventing performance index of the lubricating oil composition of Comparative Example 14 using compound J decreased to 0.94 and 1.00 or less, resulting in lack of anti-shudder vibration preventing performance. This shows that unless both R ¹ and R ² are linear hydrocarbons, the transmission torque capacity can be maintained and the anti-shudder vibration performance cannot be imparted.

As shown in Table 3, R ¹ and R ² of the compounds A to H are linear alkyl groups having 8 or more carbon atoms, and the lubricating oil composition using them has a shudder without impairing the transmission torque capacity. It has a remarkable effect on the vibration prevention performance.

Further, as understood from Comparative Examples 8 and 9, it was found that the imide compound of the present invention has a content range capable of exerting a more remarkable effect.

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[Table 1]

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[Table 2]

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[Table 3]

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[Table 4]

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The lubricating oil composition for an automatic transmission of the present invention comprises
The lubricant base oil contains the above-mentioned imide compound, and in the automatic transmission with a slip control mechanism, the slope of the μ-V curve, which is an index of anti-shudder vibration performance, can be improved, and the low speed range can be improved. Even when the lock-up mechanism is operated with, the excellent shudder vibration prevention performance can be exhibited without impairing the transmission torque capacity.

Claims (1)

[Claims] 1. A lubricating base oil having the following general formula [I] (In the above general formula [I], R ¹ and R ² may be the same or different from each other, and each has 5 carbon atoms.
The above hydrocarbon groups, R ³ is a divalent hydrocarbon group having 1 to 5 carbon atoms, and R ⁴ is a hydrogen atom or 1 to 2 carbon atoms.
It is a hydrocarbon group of 0, and n is an integer of 0-10. )
A lubricating oil composition for an automatic transmission, comprising an effective amount of a compound represented by: