JPH0380190B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a traction drive fluid,
Specifically, the present invention relates to a traction drive fluid that has excellent physical properties such as small temperature dependence of traction coefficient and is suitably used in continuously variable transmissions of automobiles and industrial machines.

In recent years, continuously variable transmissions using traction drive fluid have come into widespread use in various fields. Along with this, traction drive devices are required to be compact from the viewpoint of energy saving, and drive devices are also required to be used at high speeds and under high load conditions. Thus, when a traction drive device is used under severe conditions, it is necessary to use a traction drive fluid that exhibits sufficient performance even at high temperatures.

Various compounds have been proposed as traction drive fluids. For example, special public service in Showa 46
-338 publication, 46-339 publication, 47-35763 publication, 48-42067 publication, 48-42068 publication,
Publication No. 53-36105, Japanese Unexamined Patent Publication No. 55-43108,
Examples include those described in Publication No. 55-40726.
However, all of these had the problem that the traction coefficient decreased at high temperatures.

The inventors of the present invention have conducted extensive research to develop an excellent traction drive fluid that does not reduce its traction coefficient even at high temperatures. The present invention was completed based on the discovery that it satisfies the above object.

That is, the present invention is based on the general formula (In the formula, R ₁ and R ² represent hydrogen or a methyl group.) This is a traction drive fluid containing a compound represented by the following as a base stock.

Specifically, the compound represented by the above general formula () is the formula 1,2-di(1-decalyl)propane, represented by the formula 1-(2-decalyl)-2-(1-decalyl)propane, represented by the formula 1-(1-decalyl)-2-(2-decalyl)propane, represented by the formula 1,2-di(2-decalyl)propane, represented by the formula 2,3-di(1-decalyl)butane, represented by the formula 2-(1-decalyl)-3-(2-decalyl)butane, represented by the formula 2,3-di(2-decalyl)butane, represented by the formula 2-Methyl-1,2-di(1-decalyl)propane, represented by the formula 2-methyl-1-(2-decalyl)-
2-(1-decalyl)propane, formula 2-methyl-1-(1-decalyl)-
2-(2-decalyl)propane, formula 2-methyl-1,2-di(2-decalyl)propane, represented by the formula 2-Methyl-2,3-di(1-decalyl)butane, represented by the formula 2-methyl-2-(2-decalyl)-
3-(1-decalyl)butane, formula 2-methyl-2(1-decalyl)-3 represented by
-(2-decalyl)butane, formula Examples include 2-methyl-di(2-decalyl)butane represented by:

In the present invention, these compounds can be used alone or in combination. Among them, especially 1,2-didekarylpropanes, 2-methyl-
1,2-didekarylpropanes and the like are suitable as the base stock of the present invention because they have excellent synthesis and physical properties without decreasing their traction coefficient even at high temperatures.

The compound represented by the general formula () used as the base stock of the traction drive fluid of the present invention can be produced by various methods. Examples of preferred synthesis methods from an industrial standpoint include the following methods. i.e. naphthalene or tetralin in the presence of a Friedel-Crafts catalyst such as aluminum chloride, ferric chloride, stannic chloride, zinc chloride, trifluoroborane, hydrogen fluoride, sulfuric acid, etc. It is reacted with halides, dienes such as isoprene and butadiene, and alkyl dihalides such as 1,2-dichloropropane. In this case, it is difficult to determine the reaction conditions uniquely depending on the raw materials, catalyst, etc., but usually -
The reaction is carried out within the range of 30°C to 80°C. Thereafter, the obtained product is hydrogenated to obtain a compound represented by the general formula (). For hydrogenation, common hydrogenation catalysts such as platinum, palladium, nickel, rhodium, and ruthenium may be used. In particular, when hydrogenation is performed using platinum, many decalin rings are produced in the cis form, which is preferable in terms of traction performance.

The compound represented by the general formula () thus obtained can be used as is as a traction drive fluid and exhibits an excellent traction coefficient. Further, since the compound represented by the general formula () can be produced relatively inexpensively by the above-mentioned method, the traction drive fluid of the present invention is also inexpensive.

The traction drive fluid of the present invention can maintain a high traction coefficient over a wide range from low temperatures to high temperatures (80 to 140°C), and can not only contribute to the miniaturization of drive devices but also contribute to high-speed and high-speed It can withstand use under severe load conditions.

Therefore, the traction drive fluid of the present invention can be widely used in various mechanical products such as automobiles, industrial continuously variable transmissions, and hydraulic equipment.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 3960 g of tetralin and 120 g of anhydrous ferric chloride were placed in a flask with an internal volume of 5, and while stirring at room temperature, 634 g of methallyl chloride was gradually added dropwise over 8 hours, and the mixture was stirred for an additional hour to react. I let it happen. Next, 1 part of water was added to this, and the oil layer was separated and collected, washed three times each with 1 part of 1N NaOH aqueous solution and 1 part of saturated saline solution, and dried over anhydrous sodium sulfate. Next, the product was distilled to remove unreacted tetralin, and further distilled under reduced pressure to obtain 500 g of a fraction with a boiling point range of 165 to 195°C (0.12 mmHg). The main component of this fraction was 2-methyl-1,2-ditetralinpropanes.

Next, the product was placed in an autoclave No. 1, 50 g of activated 0.5% platinum-alumina catalyst (manufactured by Nippon Engelnardo) was added, and the hydrogen pressure was increased to 50
Hydrogenation treatment was carried out at Kg/cm ² G and a temperature of 200° C. for 4 hours. As a result of removing light components from the product and analyzing it, it was confirmed that the main component was 2-methyl-1,2-didekarylpropanes. The product obtained has a refractive index n ²⁰ _D 1.5123 and a specific gravity 0.96
(15/4°C) and kinematic viscosity of 13cst (100°C).

Figure 1 shows the results of measuring the traction coefficient over a temperature range of 50°C to 140°C.

The traction coefficient was measured using a two-cylinder friction tester. In other words, one cylinder of the same size (diameter 60 mm, thickness 6 mm) that is in contact with a line is rotated at a constant speed (2000 r.pm), and the other cylinder is rotated at a slower constant speed (1700 r. pm).
A load of 140 kg was applied by a spring to the contact area between both cylinders, and the torque was measured using a strain gauge and a torque meter to determine the traction coefficient. This cylinder is made of carbon steel SOM-3, the surface is buffed with alumina (0.03μ), the surface roughness is Rmax = 0.2μ, and the Hertzian contact pressure is
It was 75Kg/ ^mm2 . During measurement, the oil temperature can be adjusted from room temperature by heating the oil tank with a heater.
The temperature was varied up to 140°C.

Example 2 Example 1 except that 100 g of anhydrous aluminum chloride was used instead of anhydrous ferric chloride, 383 g of allyl chloride was used instead of methallyl chloride, and the reaction temperature was 10°C. The reaction was carried out in the same manner as in 1, and the boiling point was 155~
750g of fraction at 175°C (0.1mmHg) was obtained. This fraction
500g was hydrogenated in the same manner as in Example 1 to obtain 1,
The main component is 2-didekarylpropanes, and 1 other
550 g of a product containing some amount of -decalyl-4-phenylbutane and 1,2'-bisdecalin was obtained. The obtained product has a refractive index n ²⁰ _D 1.5066 and a specific gravity 0.94 (15/
4°C) and kinematic viscosity of 7.5cst (100°C).

The traction coefficient was set to 30 in the same manner as in Example 1.
Figure 1 shows the results of measurements over the temperature range from ℃ to 130℃.

Comparative Example 1 α-methylstyrene was added to the glass flask of 3.
1000g and 50g of acid clay and ethylene glycol
50g was added and reacted at 140°C for 2 hours with stirring. After filtering off the catalyst from the reaction solution, unreacted α-methylstyrene and ethylene glycol were distilled off to obtain 900 g of a fraction with a boiling point of 125-130°C/0.2 mmHg.
As a result of NMR analysis and gas chromatography analysis, this fraction was found to be a linear dimer of α-methylstyrene.
% and 5% cyclic dimer.

This fraction was hydrogenated and post-treated in the same manner as in Example 1 to obtain a traction drive fluid containing 2,4-dicyclohexyl-2-methylpentane as a main component. The specific gravity of this thing is 0.90 (15/4
℃), kinematic viscosity 22cst (40℃), 3.7cst (100℃),
The viscosity index was 16.

The traction coefficient of this material was measured in the same manner as in Example 1 over a temperature range of 25°C to 100°C, and the results are shown in FIG.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the traction coefficient and oil temperature for the traction drive fluid of the present invention.

Claims (1)

[Claims] 1. General formula (In the formula, R ¹ and R ² represent hydrogen or a methyl group.) A traction drive fluid containing a compound represented by the following as a base stock.