JPH10306292A - Automatic transmission oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an automatic transmission oil composition having a performance giving a long life of shudder prevention in a slip lockup apparatus and a performance giving a long life of scratch noise prevention in a belt-type CVT apparatus. SOLUTION: This automatic transmission oil composition is obtained by compounding a base oil with (A) a Ca-sulfonate having a total base value of 50-100 mgKOH/g and (B) a phosphite. Further, the composition is compounded with at least one kind of a friction conditioner selected from (C) a sarcosine derivative and (D) a reaction product of a carboxylic acid with an amine. The base oil may contain a viscosity index improver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission oil composition, and more particularly to a lubricating oil for an automatic transmission with a slip lockup device and / or a lubricating oil for a belt type CVT (continuously variable transmission) automatic transmission. The present invention relates to an automatic transmission oil composition suitable for:

[0002]

2. Description of the Related Art Conventionally, a force generated by an engine of an automobile has been transmitted from a gear to a tire through a lock-up automatic transmission or a slip lock-up automatic transmission. Recently, a new automatic transmission system has been developed in view of demands for fuel economy and improvement of ride comfort. In this system, the force is transmitted in the order of the engine, the slip lock-up device, the belt type CVT, the gear, and the tire, or the engine, the belt type CVT, the slip lock-up device, the gear, and the tire. However, this new automatic transmission system has two problems. The first problem is that a torque fluctuation on the output side of the slip lockup device occurs, and the vehicle body vibrates.
That is, a shudder phenomenon occurs. The second problem is that the output-side rotation speed of the belt-type CVT fluctuates, and an abnormal sound is heard inside the vehicle. That is, a scratch noise phenomenon occurs.
These two problems may arise from a new vehicle or from a certain traveling distance, and in both cases, it is required to solve them with lubricating oil.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and has a long service life of preventing shudder for a slip lock-up device and preventing scratch noise for a belt type CVT device. It is an object of the present invention to provide an automatic transmission oil composition having a long life.

[0004]

Means for Solving the Problems As a result of extensive studies, the present inventors have achieved the object of the present invention effectively by using specific Ca-sulfonates and phosphites as additives. It was found that the present invention was completed. That is, the present invention provides an automatic transmission oil composition comprising (A) a Ca-sulfonate having a total base number of 50 to 100 mgKOH / g and (B) a phosphite, and C) sarcosine derivatives,
(D) An automatic transmission oil composition comprising at least one friction modifier selected from the reaction product of a carboxylic acid and an amine.

[0005]

Embodiments of the present invention will be described below. First, in the lubricating oil composition for an automatic transmission according to the present invention, a mineral oil and / or a synthetic oil is used as a base oil. The mineral oil and the synthetic oil may be those generally used as a base oil of a transmission oil, and are not particularly limited, but have a kinematic viscosity at 100 ° C. of 1 to 20 mm ² /.
s, particularly those in the range of ^{2 to 10} mm ² / s are preferred. If the kinematic viscosity of the base oil is too high, the low-temperature viscosity will deteriorate,
On the other hand, if it is too low, wear on sliding parts such as gear bearings and clutches of the automatic transmission increases, which is not preferable. The pour point, which is an index of the low-temperature fluidity of the base oil, is not particularly limited, but is preferably −10 ° C. or less.

[0006] There are various types of such mineral oils and synthetic oils, and they may be appropriately selected depending on the use and the like. Examples of the mineral oil include paraffinic mineral oil, naphthenic mineral oil, intermediate mineral oil, and the like. Specific examples thereof include light neutral oil, medium neutral oil, heavy neutral oil, heavy neutral oil, and bright stock obtained by solvent refining or hydrorefining. And the like.

On the other hand, synthetic oils include, for example, poly-α-olefin, α-olefin copolymer, polybutene, alkylbenzene, polyol ester, dibasic acid ester, polyoxyalkylene glycol, polyoxyalkylene glycol ester, polyoxyalkylene glycol ether, Hindered esters, silicone oils and the like can be mentioned.

These base oils can be used alone or in combination of two or more, and mineral oil and synthetic oil may be used in combination. In the present invention, the base oil preferably contains a viscosity index improver. As the viscosity index improver that can be used, an olefin (co) polymer such as an ethylene-propylene copolymer, polymethacrylate, polyisobutylene, or the like is preferably used, and polymethacrylate is particularly preferably used from the viewpoint of low-temperature characteristics. Its molecular weight is 10,000 to 1,000,000 in terms of number average molecular weight from the viewpoint of shear stability and the like.
00, even 10,000-100,000, especially 10,
It is preferably in the range of 000 to 70,000. The base oil containing the viscosity index improver particularly has a viscosity index (VI) of 130 from the viewpoint of low temperature starting performance.
Above, especially those having 160 or more are preferably used.

Next, the components (A) to (D) blended in the base oil will be described. (A) Component The overbased Ca-sulfonate is a calcium metal salt of various sulfonic acids, and is usually obtained by a method of carbonating a calcium metal salt of various sulfonic acids. Examples of the sulfonic acid include aromatic petroleum sulfonic acid, alkylsulfonic acid, arylsulfonic acid, and alkylarylsulfonic acid, and specifically, dodecylbenzenesulfonic acid,
Examples include dilauryl cetyl benzene sulfonic acid, benzene sulfonic acid substituted with paraffin wax, benzene sulfonic acid substituted with polyolefin, benzene sulfonic acid substituted with polyisobutylene, and naphthalene sulfonic acid.

The above-mentioned overbased Ca-sulfonate has a total base number of 50 to 100 mgKOH / g, preferably 60 to 9 mgKOH / g.
0 mgKOH / g. If the total base number is too high, the life of the belt type CVT for preventing scratch noise is short, and if the total base number is too low, the scratch noise prevention performance of the belt type CVT is inferior, which is not preferable. The total base number is based on JISK
It is a value measured by -2501 (perchloric acid method). The overbased Ca-sulfonate is preferably blended at a ratio of 0.1 to 5% by weight, more preferably 0.3 to 3% by weight, based on the total amount of the composition, based on the base oil.

[0011] The component (B) phosphites include phosphites and acidic phosphites represented by the following general formulas (I) and (II).

[0012]

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[0013]

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In the above general formulas (I) and (II), R ¹
To R ³ are an alkyl group having 4 to 30 carbon atoms, an alkenyl group,
An alkylaryl group and an arylalkyl group,
^{1 to} R ³ may be the same or different. As the phosphite, specifically, for example, triethyl phosphite, tributyl phosphite, triphenyl phosphite, tricresyl phosphite, tri (nonylphenyl) phosphite, tri (2-ethylhexyl) phosphite, tri Decyl phosphite, trilauryl phosphite, triisooctyl phosphite, diphenyl isodecyl phosphite, tristearyl phosphite,
Trioleyl phosphite and the like can be mentioned.

Specific examples of the acidic phosphite include dibutyl hydrogen phosphite, dilauryl hydrogen phosphite, dioleyl hydrogen phosphite, distearyl hydrogen phosphite, and diphenyl hydrogen phosphite. it can. Among the above phosphites, acidic phosphites such as dilauryl hydrogen phosphite, dioleyl hydrogen phosphite, and distearyl hydrogen phosphite are preferred.

The phosphites are preferably blended in a proportion of 0.01 to 5% by weight, more preferably 0.1 to 3% by weight, based on the total amount of the composition with respect to the base oil. The present invention can achieve the object only by blending the above components (A) and (B) with the base oil. However, if desired, a friction modifier selected from the following (C) and (D) can be used. Is a preferred embodiment. As the component (C) sarcosine derivative, N-acylated sarcosine such as oleyl sarcosine and stearyl sarcosine is preferably used. (D) The carboxylic acid to be reacted with the component amine includes an aliphatic carboxylic acid, an aliphatic dicarboxylic acid (dibasic acid) and an aromatic carboxylic acid, wherein the aliphatic carboxylic acid has 8 to 30 carbon atoms. , Saturated or unsaturated,
Further, it may be linear or branched. Specific examples of aliphatic carboxylic acids include pelargonic acid, lauric acid,
Examples include tridecanoic acid, myristic acid, palmitic acid, stearic acid, isostearic acid, eicosanoic acid, behenic acid, triacontanic acid, caproleic acid, undecylenic acid, oleic acid, linolenic acid, erucic acid, and linoleic acid. Specific examples of the aliphatic dicarboxylic acid include octadecyl succinic acid, octadecenyl succinic acid, adipic acid, azelaic acid, and sebacic acid. Examples of the aromatic carboxylic acid include salicylic acid.

On the other hand, the amine to be reacted with the carboxylic acid is diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctamine, dipropylenetriamine, tetrapropylenepentamine, hexabutylene. Examples thereof include polyalkylene polyamines such as heptamine and alkanolamines such as monoethanolamine and diethanolamine.

Of these, combinations of isostearic acid and tetraethylenepentamine, and oleic acid and diethanolamine are preferred. The components (C) and (D) are preferably 0.01 to 5% by weight, more preferably 0.1 to 4% by weight, based on the total amount of the composition, based on the base oil.
In the proportion of In the automatic transmission oil composition of the present invention, in addition to the above components, if necessary, a metal deactivator such as a copper deactivator in terms of preventing corrosion of non-ferrous metals,
An antioxidant, an ashless dispersant, an antifoaming agent and the like can be appropriately compounded.

The metal deactivator includes, for example, benzotriazole, thiadiazole and the like, and is usually used at a ratio of 0.01 to 5% by weight based on the total amount of the composition. Examples of the antioxidant include alkylated diphenylamine, phenyl-α-naphthylamine, and alkylated-α-
Amine-based antioxidants such as naphthylamine, dialkylthiodipropionate, dialkyldithiocarbamic acid derivatives (excluding metal salts), bis (3,5-di-t-butyl-4-hydroxybenzyl) sulfide, mercaptobenzothiazole, Examples of the reaction product include a reaction product of phosphorus sulfide and an olefin, and a sulfur-based antioxidant such as dicetyl sulfide. Usually, it is used at a ratio of 0.05 to 3% by weight based on the total amount of the composition.

The ashless dispersant includes, for example, polyalkenylimides, benzylamines and the like, and is usually used at a ratio of 0.05 to 5% by weight based on the total amount of the composition. Examples of the antifoaming agent include a silicone compound and an ester compound, and usually, based on the total amount of the composition,
It is used in a proportion of 0.05 to 5% by weight.

[0021]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Various performance test methods in Examples and Comparative Examples were performed as follows.

(1) Anti-shudder performance and transmission torque capacity in a slip lock-up device (1-a) Anti-shudder performance Low-speed slip tester (hereinafter referred to as LVFA) as a tester
The use, in the following experimental conditions, respectively measured mu _L and mu _H,
It was calculated μ _L / μ _H ratio. Experimental conditions (conditioned immediately) and friction material: Wet paper materials, oil temperature: 80 ° C., oil quantity: 150 cc · surface pressure: 10kgf / cm ² μ _L of friction coefficient in ... the relative slip speed 0.3 m / s mu the _H · · · relative slip speed 0.9 m / s friction coefficient in the evaluation method μ _L / μ _H ratio is anti-shudder performance index was a criterion of anti-shudder effect. Because if μ _L / μ _H ≦ 1 that shudder in actual does not occur has been confirmed, as the anti-shudder performance, shudder performance index 1.
Those having a value of 00 or less are evaluated as excellent.

(1-b) Anti-shudder life A continuous slip durability test was performed using an LVFA as a tester under the following experimental conditions. Experimental conditions and friction material: Wet paper materials, oil temperature: 120 ° C., oil quantity: 150 cc · surface pressure: 10 kgf / cm ² · Speed 0.9 m / s Evaluation mu _L / mu time _H ratio greater than 1.0 Was evaluated.

(1-c) Transfer Torque Capacity A dynamic test and a static test were performed using a SAE No. 2 friction tester as a tester under the following conditions. -Friction material: wet paper material-Oil temperature: 110 ° C-Oil amount: 800 cc-Surface pressure: 8 kgf / cm ² [Danamic test] The friction material is rotated at 3000 rpm.
m, no-load rotation with an inertial weight of 3.0 kgf · cm · s ² , pressure is applied so that a friction material is sandwiched between steel plates, and rotation is stopped. [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 a friction coefficient is calculated from a rotation torque generated at that time. Measuring the static friction coefficient mu _S in the maximum torque slipping at low speed rotation. Evaluation method The evaluation of the transmission torque capacity was performed according to SAE No. Carried out by static friction coefficient mu _S in two tests, mu _S is evaluated as a large transmission torque capacity higher by 0.12 or more.

(2) Scratch noise prevention performance and transmission torque capacity in belt type CVT (2-a) Scratch noise prevention performance Using a two-plane tester as a tester, μ was obtained under the following experimental conditions.
Each measured _L and mu _H, was calculated mu _L / mu _H ratio. Experimental conditions and friction material: Steel - Steel - oil temperature: 130 ° C., oil quantity: 500 cc · surface pressure: 22kgf / cm ² μ _L ··· coefficient of friction relative slip speed 0.05m / s μ _H ··· relative The friction coefficient evaluation method at a slip speed of 0.20 m / s The μ _L / μ _H ratio was used as the scratch noise prevention performance index, and was used as a criterion for determining the scratch noise prevention effect. μ _L / μ _H
Since it is confirmed that scratch noise does not occur in the actual machine if ≦ 1, it is evaluated that the scratch noise prevention performance index having a scratch noise prevention performance index of 1.00 or less is excellent.

(2-b) Scratch noise prevention life ISOT test (based on JIS K-2514; oil temperature 15)
(0 ° C, 48 hours) to produce degraded oil.
Under the above experimental conditions using a two-plane testing machine. _LAnd μ
_HIs measured and the scratch noise prevention performance index (μ_L/ Μ
_HRatio) was evaluated. Scratch noise prevention life
If the scratch noise prevention figure of merit is 1.00 or less,
If there is, it will be evaluated as excellent.

[0027] (2-c) using a biplanar tester as the transmission torque capacity tester under the following conditions, to measure the friction coefficient mu _T relative slip speed 0.05 m / s.・ Friction material: steel-steel ・ Oil temperature: 100 ° C. ・ Oil amount: 500 cc ・ Surface pressure: 110 kgf / cm ² Evaluation method The transmission torque capacity is evaluated based on the friction coefficient μ _T and μ _T
Is higher than 0.11, it is evaluated that the transmission torque capacity is larger. [Examples 1 to 6, Comparative Examples 1 to 6] At the ratios shown in Table 1,
Each component was blended with the base oil to prepare automatic transmission oil compositions of Examples and Comparative Examples. The various performance tests described above were performed on these examples and comparative examples. Table 1 shows the results.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

[Table 4]

* 1 Paraffinic mineral oil, kinematic viscosity 5.0 m
m ² / s (100 ° C.) * 2 Number average molecular weight 50,000 * 3 Total base number 80 mg KOH / g (JIS K-25
01: Perchloric acid method) * 4 Total base number 400 mgKOH / g (JIS K-2
501: Perchloric acid method) * 5 Dioleyl hydrogen phosphite * 6 Tricresyl phosphate amine salt * 7 Oleylsarcosine * 8 Reaction product of isostearic acid and tetraethylenepentamine * 9 Antioxidant, ashless dispersant, metal inactivating agent, from table 1 defoamers, compositions of Comparative examples 1 to 3 in unacceptable scratch noise prevention lifetime (μ _L / μ _H ratio after ISOT test), the composition of Comparative example 4-6 things shudder life (mu _L /
It can be seen mu _H ratio is unacceptable in excess of 1.0 times).

[0033]

As described above, the automatic transmission oil composition of the present invention has a long life of preventing shudder against a slip lock-up device and a long life of preventing scratch noise against a belt type CVT device. In particular, the present invention provides an automatic transmission oil composition suitable for a lubricating oil for an automatic transmission with a slip lockup device and / or a lubricating oil for a belt-type CVT (continuously variable transmission) automatic transmission.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10N 10:04 30:00 30:02 30:04 40:04

Claims (6)

[Claims] 1. The base oil contains (A) a total base number of 50 to 100 m.
Ca-sulfonate having gKOH / g, and (B)
An automatic transmission oil composition containing phosphites. 2. The automatic transmission oil composition according to claim 1, wherein the base oil contains a viscosity index improver. 3. The automatic transmission oil composition according to claim 1, further comprising (C) a sarcosine derivative and (D) at least one friction modifier selected from a reaction product of a carboxylic acid and an amine. Stuff. 4. The automatic transmission oil composition according to claim 1, wherein the automatic transmission oil composition is a lubricating oil for an automatic transmission with a slip lockup device. 5. The automatic transmission oil composition according to claim 1, wherein the automatic transmission oil composition is a lubricating oil for a belt-type CVT automatic transmission. 6. The automatic transmission oil composition according to claim 1, wherein the automatic transmission oil composition is a lubricating oil for an automatic transmission using a slip lock-up device and a belt type CVT together.