JP3295671B2 - Lubricating oil composition for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel lubricating oil composition for an automatic transmission, and more particularly, to a high-speed automatic transmission for automobiles, while maintaining a high torque transmission capacity and having excellent shifting shock prevention performance. It relates to a suitable lubricating oil composition.

[0002]

BACKGROUND OF THE INVENTION Lubricating oil for automatic transmissions (Automati)
c Transmission Fluid (abbreviated as ATF) is a lubricating oil used for an automatic transmission of an automobile having a built-in torque converter, gear mechanism, hydraulic mechanism, wet clutch, and the like. For smooth operation of automatic transmission mechanism, ATF is used for torque converter, hydraulic system, power transmission medium in control system, gear bearing, lubrication of wet clutch, heat medium for temperature control, lubrication of friction material, proper It is required to have many functions such as maintenance of various friction characteristics. 2. Description of the Related Art With the recent spread of automatic transmissions in the field of automobiles, there has been an increasing demand for ATFs having particularly excellent friction characteristics. By the way, conventionally, ATF has emphasized low-speed sliding performance and shift shock prevention performance, and has adopted a friction modifier (FM:
These performances have been satisfied by a large amount of friction modifiers). However, the use of a large amount of FM, which emphasizes degenerative shock prevention performance, reduces the static friction coefficient (μs) although the low-speed sliding performance and shift shock prevention performance are excellent, but the torque is transmitted by the automobile manufacturer's hardware (friction material). The capacity is currently being increased. Generally, SAE No. 2 tester is widely used as a simulation tester for frictional characteristics of ATF. As a general index, the torque transmission capacity at the start and the high-speed rotation (slip speed of 0.
Μs (static friction coefficient) and μo (final friction coefficient) / μ for a shift shock prevention performance of 5 to 10 m / s), respectively.
d (dynamic friction coefficient) is used. This μs and μo
/ Μd depends on the type of friction material,
The relative difference between the frictional performances can be evaluated. As the needs of automobile manufacturers and users, high torque transmission capacity (μs: 0.14 or more) and good shift shock prevention performance (μo / μd: 1.1 or less, preferably 1.05 or less) are required. The conventional ATF has reduced μo / μd to 1.05 to 1.1 or less by using a large amount of FM, but it is difficult to maintain μs to 0.14 or more,
The reality is that the torque transmission capacity has been sacrificed to some extent.

[0003]

SUMMARY OF THE INVENTION Under such circumstances, the present invention maintains a high torque transmission capacity,
Another object of the present invention is to provide a lubricating oil composition having excellent shift shock prevention performance and particularly suitable for use in automatic transmissions of automobiles.

[0004]

The present inventors have conducted intensive studies to develop a lubricating oil composition for an automatic transmission having the above-mentioned preferable properties. By mixing the amine compound, the overbased calcium phenate and the two specific ashless dispersants at a predetermined ratio, the high torque transmission capacity is maintained, and the shift shock is effectively prevented. It has been found that a lubricating oil composition having excellent properties can be obtained. The present invention has been completed based on such findings. That is, the present invention relates to a lubricating base oil based on the total amount of the composition (A)

[0005]

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(Wherein R ¹ is a hydrocarbon group having 10 to 30 carbon atoms, y and z are each an integer of 1 to 5 and they may be the same or different). At least one selected from the group consisting of 0.01 to 3.0% by weight, and (B) a general formula

[0007]

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(Wherein R ² and R ⁴ each have 5 to 5 carbon atoms)
At least one selected from the group consisting of calcium phenate represented by the formula: 28 alkyl groups, R ³ and R ⁵ are each a hydrogen atom or an alkyl group having 1 to 28 carbon atoms, and x is an integer of 1 to 5). 0.05 to 5.0% by weight, and (C) (a)
General formula

[0009]

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Wherein R ⁶ is an oligomer residue having a molecular weight of 500 to 5,000, and m is an integer of 4 to 6. At least one of succinimide-based ashless dispersants represented by the formula: 0.5-5.0% by weight, and (b) general formula

[0011]

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(Wherein R ⁷ is an oligomer residue having a molecular weight of 500 to 5,000 and n is an integer of 4 to 6) selected from among B-shielded succinimide-based ashless dispersants represented by the following formula: It is intended to provide a lubricating oil composition for an automatic transmission, wherein one kind of the lubricating oil composition is blended with 0.5 to 5.0% by weight.

Hereinafter, the present invention will be described in detail. The base oil used in the lubricating oil composition of the present invention is not particularly limited, and those conventionally used as base oils for lubricating oils, for example, mineral oils and synthetic oils are used. As mineral oil,
For example, 60 neutral oil, 100 neutral oil, 150 neutral oil, 3
Examples include 00 neutral oil, 500 neutral oil, and a low pour point base oil in which low-temperature fluidity is improved by removing a wax component from these base oils. These may be used alone, or two or more kinds may be suitably used. You may mix and use it at an appropriate ratio. On the other hand, examples of the synthetic oil include poly-α-olefin oligomers, diesters, polyol esters, polyglycol esters, and the like. These base oils are usually used alone, but can be used by mixing with the mineral oil. . The mixing ratio of the synthetic oil and the mineral oil is, for example, a weight ratio of 80:20 to 20:80. As the base oil used in the composition of the present invention, one having a viscosity at 100 ° C. in the range of 3 to 20 cSt is suitable. In the lubricating oil composition of the present invention, as the component (A), a general formula

[0014]

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(Wherein R ¹ , y and z have the same meanings as described above). In the general formula [1], R ¹ is a hydrocarbon group having 10 to 30 carbon atoms, for example, an alkyl group, an alkenyl group, an aryl group, an alkylaryl group, an arylalkyl group having 10 to 30 carbon atoms. The alkyl group or alkenyl group may be linear or branched.
Specific examples of R ¹ include preferably decyl, lauryl, myristyl, palmityl, stearyl, oleyl, eicosyl and the like. Examples of the amine compound represented by the general formula [1] include lauryl diethanolamine, myristyl diethanolamine, palmityl diethanolamine, stearyl diethanolamine, oleyl diethanolamine, and 2 to 4 moles of ethylene oxide adduct thereof. One of these amine compounds may be used,
A combination of more than one species may be used. The amine compound of the component (A) may be blended in an amount of 0.01 to 3.0% by weight, preferably 0.05 to 1.0% by weight based on the total amount of the lubricating base oil. is necessary. If the amount is less than 0.01% by weight, the shifting shock prevention performance is inferior, and if it exceeds 3.0% by weight, the torque transmission capacity decreases. In the lubricating oil composition of the present invention, the component (B) has a general formula

[0016]

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(Wherein R ² , R ³ , R ⁴ , R ⁵ and x have the same meanings as described above), and at least one member selected from the group consisting of calcium phenates is used. In the general formulas [2] and [3], R ² and R ⁴ are each an alkyl group having 5 to 28 carbon atoms, and R ³ and R ⁵ are each a hydrogen atom or an alkyl group having 1 to 28 carbon atoms. . These alkyl groups may be linear or branched. Specific examples of R ² and R ⁴ include a pentyl group, a hexyl group, an octyl group, a nonyl group, a decyl group,
A dodecyl group, a pentadecyl group, an octadecyl group and the like. On the other hand, specific examples of R ³ and R ⁵ include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, and a pentadecyl group. And an octadecyl group. X is an integer of 1 to 5. In the present invention, at least one of the calcium phenates represented by the general formulas [2] and [3] is selected.
Seeds can be used. Among calcium phenates, overbased calcium phenates are particularly preferable. The calcium phenate of the component (B) is blended in a range of 0.05 to 5.0% by weight, preferably 0.05 to 3.0% by weight based on the total amount of the lubricating base oil. is necessary. If the amount is less than 0.05% by weight, a high torque transmission capacity cannot be obtained, and the cleaning effect is insufficient. If the amount exceeds 5.0% by weight, abrasion resistance is poor,
In addition, ash content is undesirably increased. In the lubricating oil composition of the present invention, as the component (C), (A) a general formula

[0018]

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A succinimide-based ashless dispersant represented by the formula (R ⁶ and m have the same meanings as described above):
General formula

[0020]

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(Wherein R ⁷ and n have the same meanings as described above) in combination with a B-shielded succinimide-based ashless dispersant represented by the formula: The reason for the effect of improving the frictional properties of these succinimide derivatives is not necessarily clear, but is presumed as follows. That is, the succinimide derivative causes competitive adsorption with FM on the friction surface,
It is considered that the adsorption state of FM is controlled to provide stable friction characteristics. In the general formulas [4] and [5], R ⁶ and R ⁷ are oligomer residues having a molecular weight of 500 to 5000, and as such a compound, for example, a polybutenyl group can be preferably mentioned. Further, m and n are integers of 4 to 6. The succinimide-based ashless dispersant of the component (A) may be used alone or in combination of two or more. The B-shielded succinimide-based ashless dispersant of the component (ii) may be used alone or in combination of two or more. In the lubricating oil composition of the present invention, the succinimide-based ashless dispersant of the component (A) and the B-shielded succinimide-based ashless dispersant of the component (B) are preferably added to the lubricating base oil. Also needs to be added in the range of 0.5 to 5.0% by weight, preferably 1.0 to 3.0% by weight. If the compounding amount is less than 0.5% by weight, the torque transmission capacity is reduced, and the dispersibility of the deteriorated material is poor.
If it exceeds 5% by weight, the shifting shock prevention performance is reduced.
In the lubricating oil composition of the present invention, if necessary, an antiwear agent,
Viscosity index improver, pour point depressant, antioxidant, rust inhibitor,
Corrosion inhibitors, defoamers, other friction modifiers and the like can be added as appropriate. Examples of the antiwear agent include metal thiophosphates (Zn, Pb, Sb, Mo, etc.), metal thiocarbamates (Zn, etc.), sulfur compounds, phosphates, phosphites and the like. These are usually used in a proportion of 0.05 to 5.0% by weight. Examples of the viscosity index improver include polymethacrylates,
Examples thereof include polyisobutylene-based, ethylene-propylene copolymer-based, and styrene-butadiene hydrogenated copolymer-based copolymers, which are generally used at a ratio of 0.5 to 35% by weight. Examples of the antioxidant include amine antioxidants such as alkylated diphenylamine, phenyl-α-naphthylamine, and alkylated-α-naphthylamine;
6-di-t-butyl-4-methylphenol, 4,4'-
And phenolic antioxidants such as methylenebis (2,6-di-t-butylphenol).
Usually, it is used in a proportion of 0.05 to 2% by weight. As the rust inhibitor, for example, alkenyl succinic acid or its partial ester, etc., as the corrosion inhibitor, for example, benzotriazole or benzimidazole, as the defoaming agent, for example, dimethyl polysiloxane or polyacrylate, These can be appropriately added.

[0022]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. Examples 1 to 7 and Comparative Examples 1 to 9 Lubricating oil compositions having the compositions shown in Table 1 were prepared, and SAEN was prepared.
o.2 Using a friction tester, the torque transmission capacity and shift shock prevention performance were evaluated under the following experimental conditions. Disc: Pavers for domestic automatic transmission, Plate: Steel for automatic domestic transmission, Motor speed:
0-3600 rpm, pressing pressure: 8 kgf / cm ² , oil temperature: 120
Under the experimental conditions of ° C., the clutch engagement pattern (connection and disengagement) is defined as the static friction coefficient (μs) and the ratio of the static friction coefficient (μo) to the dynamic friction coefficient (μd) (μo / μd) at 500 cycles and 5000 cycles. Then, the torque transmission capacity and shift shock prevention performance were evaluated, respectively. The results are shown in Table 1.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

[Table 3]

[0026]

According to the present invention, it is possible to obtain a lubricating oil composition for an automatic transmission which maintains a high torque transmission capacity, has excellent shift shock prevention performance, and also has excellent sustainability of these performances.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI C10M 129: 10 C10M 129: 10 133: 08 133: 08 133: 56 133: 56 135: 30 135: 30 139: 00) 139: 00) A (C10M 161/00 (C10M 161/00 129: 10 129: 10 133: 08 133: 08 135: 30 135: 30 149: 02 149: 02 155: 00) 155: 00) (C10M 163/00 (C10M 163 / 00 133: 08 133: 08 133: 56 133: 56 139: 00 139: 00 A 159: 22) 159: 22) (C10M 167/00 (C10M 167/00 133: 08 133: 08 149: 02 149: 02 155: 00 155: 00 159: 22) 159: 22) C10N 10:04 C10N 10:04 30:00 30:00 Z 40:04 40:04 (56) References JP-A-51-31369 (JP, A) JP-A-2-53895 (JP, A) JP-A-2-4897 (JP, A) JP-A-3-39399 (JP, A) JP-A-48-94702 (JP, A) JP-A-2 -51591 (JP, A) Special Table 7-508049 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) C10M 141/12 C10M 129/10-129/14 C10M 133/08 C10M 133/56 C10M 135/30 C10M 139/00 C10M 149/02 C10M 155/00 C 10M 159/22 C10M 161/00 C10M 163/00 C10M 167/00 C10N 10:04 C10N 30:00 C10N 40:04

Claims (1)

(57) [Claims] (1) a lubricating base oil, based on the total amount of the composition, (A) a general formula: (Wherein R ¹ is a hydrocarbon group having 10 to 30 carbon atoms, y and z are each an integer of 1 to 5, and they may be the same or different). At least one
0.01 to 3.0% by weight of the seed and (B) a general formula (In the formula, R ² and R ⁴ are each an alkyl group having 5 to 28 carbon atoms, and R ³ and R ⁵ are each a hydrogen atom or 1 carbon atom.
(C) (a) general formula (C) (a) wherein at least one of 0.05 to 5.0% by weight selected from calcium phenates represented by Formula 3 (Wherein R ⁶ is an oligomer residue having a molecular weight of 500 to 5,000, and m is an integer of 4 to 6) at least one selected from succinimide-based ashless dispersants represented by the formula: 5.0% by weight, and (b) a general formula Wherein R ⁷ is an oligomer residue having a molecular weight of 500 to 5,000, and n is an integer of 4 to 6. At least one selected from the group consisting of a B-shielded succinimide-based ashless dispersant represented by the formula: A lubricating oil composition for an automatic transmission, wherein the lubricating oil composition contains 0.5 to 5.0% by weight.