JPH0218719B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing synthetic lubricating oil, and more particularly to a method for producing synthetic lubricating oil for traction drives having a high traction coefficient. The traction drive fluid is a fluid used in traction drive devices such as various continuously variable transmissions. This drive device is required to be miniaturized and to be used at high speed and under high load conditions. The present inventors have conducted extensive research to develop a traction drive fluid that can withstand use under such harsh conditions. It has been known that compounds having two or more naphthene rings are preferable as traction drive fluids, and the present inventors have already developed a compound represented by the following formula. It has been found that these compounds have a much higher traction coefficient at high temperatures than known compounds. These compounds are produced by dimerizing naphthalene or tetralin and then hydrogenating it, or by subjecting naphthalene or tetralin to a Friedel-Crafts reaction with alkenyl halides, alkyl dihalides, or aldehydes in the presence of a suitable catalyst such as a nickel catalyst. It can be obtained by hydrogenation,
As a result of repeated research, the present inventors discovered that a higher traction coefficient could be obtained by using a ruthenium or rhodium catalyst during hydrogenation, and based on this knowledge, they completed the present invention. . The present invention provides a method for producing a synthetic lubricating oil represented by the following formula (), which comprises hydrogenating a compound represented by the following formula () or () in the presence of a ruthenium or rhodium catalyst. (Here, X ¹ is

【formula】

【formula】

【formula】

[Formula], and R is an alkylene group having 1 to 5 carbon atoms. ) (Here, X ² is

[expression] or

[Formula], and R is an alkylene group having 1 to 5 carbon atoms. ). The compound represented by the above formula () or () is a derivative of tetralin or naphthalene, and specific examples include 1,1'-bistetralin,
1,2'-bistetralin, 1,1-ditetralylethane, 2-methyl-1,2-ditetralylpropane, 1,2-ditetralylpropane, 1,1-
Examples include dinaphthylethane and 1,1'-binaphthyl. The conditions for hydrogenating the compound represented by the above formula () or () in the presence of a ruthenium or rhodium catalyst are a temperature of 10 to 300°C, preferably 50°C.
~200℃, pressure 1~200Kg/ ^cm2G , preferably 5~
It is 50Kg/cm ² G. Note that ruthenium or rhodium is often used supported on a commonly used carrier such as silica, alumina, or activated carbon, but there are various forms in which it is used. Next, specific examples of the compound represented by formula () are shown below. formula 1,1′-bisdecalin, represented by the formula 1,2′-bisdecalin, represented by the formula 1,1'-Didekarylethane represented by the formula 2-Methyl-1,2-didekarylpropane, represented by the formula 1,2-Didekarylpropane The synthetic lubricating oil obtained by the method of the present invention has a significantly higher traction coefficient than hydrogenation using other metals such as platinum and nickel as a catalyst, and has a traction drive It is an excellent fluid for use. The reason for this is thought to be that many decalin rings are in the cis form (referring to those in which the hydrogens attached to the carbons at the 9 and 10 positions are in the cis position). The compound obtained according to the present invention can be used as it is as a base stock for a traction drive fluid, and exhibits a small change in traction coefficient from low to high temperatures, and exhibits an excellent traction coefficient. Therefore, it not only contributes to the miniaturization of the drive device, but also can withstand use under harsh conditions of high temperature and high load, and is suitable for continuously variable transmissions for automobiles, continuously variable transmissions for industrial use, It can be widely used in various equipment such as water pressure equipment. Next, examples of the present invention will be shown. In addition, the measurement of the traction coefficient in Examples and Comparative Examples was 2.
The test was carried out using a cylindrical friction tester. In other words, cylinders of the same size (diameter 52 mm, thickness 6
mm) at a constant speed (2000r.pm), and the other cylinder at a constant speed (1900r.pm) slower than that speed.
A load of 70 kg was applied to the contact area between the two cylinders using a spring, and the torque was measured using a strain gauge and a torque meter to determine the traction coefficient. This cylinder is made of bearing steel SUJ-2, the surface is buffed with alumina (0.03μ), and the surface roughness is R _nax =0.2μ. Further, the average Hertzian contact pressure was 75 Kg/mm ² . During the measurements, the oil temperature was varied from 60°C to 140°C by heating the oil tank with a heater. Example 1 3960 g of tetralin and 100 g of anhydrous aluminum chloride were placed in a 5-liter glass flask, and the temperature inside the flask was cooled to 10° C. with ice water. Next, 453 g of methallyl chloride was slowly added dropwise into the mixture over 5 hours while stirring, and the reaction was completed by further stirring for 1 hour. Then add 700 c.c. of water in the flask.
was added to decompose aluminum chloride and separate the oil layer, and this oil layer was dissolved in 1 part of a 2N aqueous sodium hydroxide solution
After washing three times each with saturated saline solution and saturated saline solution, it was dried over anhydrous sodium sulfate. Then,
After removing unreacted tetralin by distillation, vacuum distillation is performed to obtain a fraction with a boiling point of 165-175℃/0.1mmHg.
Obtained 700g. As a result of analyzing this fraction, 1,
Dimerized products of raw materials such as 2'-bistetralin and 1,1'-bistetralin, and 1-tetralyl-
The main component is a 2:1 (molar ratio) mixture of ring-opened dimers of raw materials such as 4-phenylbutane, and may contain a small amount of 2-methyl-1,2-ditetralylpropanes as a subcomponent. confirmed. 500 c.c. of this product was placed in autoclave 1, 10 g of 5% ruthenium carbon catalyst for hydrogenation (manufactured by Nippon Engelhard) and 10 g of water were added, and the hydrogen pressure was 50 Kg/cm ² and the reaction temperature was 150°C. He carried out transformation. After cooling, the reaction solution was filtered to separate the catalyst. After stripping the light components, analysis revealed that the hydrogenation rate was 99.9% or higher, and this product was found to contain dimerized hydrogenated products such as 1,2'-bisdecalin and 1,1'-bisdecalin, and 1-decalyl-4-
It was confirmed that the main component was a 1:2 (mole ratio) mixture of ring-opening dimerized hydrogenates such as cyclohexylbutane, and a small amount of 2-methyl-1,2-decarylpropanes was included as a subcomponent. Ta. The specific gravity of this material is 0.95 (15/4°C), and the kinematic viscosity is 75 cSt (40
°C), 7.0 cSt (100 °C), and the refractive index n ²⁰ _D was 1.5108. The traction coefficient of this thing is from 60℃ to 140℃
Figure 1 shows the results of measurements over a temperature range of . Comparative Example 1 Hydrogenation in Example 1 was carried out using 25 g of a nickel catalyst for hydrogenation (manufactured by JGC Chemical Co., Ltd., trade name "N-113 Catalyst").
The same procedure was carried out except that the hydrogen pressure used was 50 Kg/cm ² and the reaction temperature was 200°C. The resulting mixture had a specific gravity of 0.95 (15/4°C), a kinematic viscosity of 65 cSt (40°C) and 6.2 cSt (100°C), and a refractive index n ²⁰ _D of 1.5093. The traction coefficient of this thing is from 60℃ to 140℃
Figure 1 shows the results of measurements taken over a temperature range up to Example 2 The reaction was carried out in the same manner as in Example 1 except that 383 g of allyl chloride was used in place of methallyl chloride in Example 1, and the boiling point was 155 to 175°C.
(0.1 mmHg) was obtained. 500g of this distillate
was hydrogenated in the same manner as in Example 1, except that 15 g of a 5% rhodium-carbon catalyst (manufactured by Nippon Engelhard) was used, and 1,2-didecalylpropanes were the main component, and 1-decalyl was added as the main component. 515 g of a product containing some -4-cyclohexylbutane and 1,2-bisdecalin was obtained. The obtained product has a refractive index n ²⁰ _D 1.5076, a specific gravity 0.94 (15/4°C), and a kinematic viscosity.
They were 90cSt (40℃) and 7.6cSt (100℃). The traction coefficient of this material was measured over a temperature range of 60°C to 140°C, and the results are shown in Figure 2. Comparative Example 2 In Example 2, hydrogenation was carried out using 25 g of a nickel catalyst for hydrogenation (manufactured by JGC Chemical Co., Ltd., trade name "N-113 Catalyst") at a hydrogen pressure of 50 kKg/cm ² and a reaction temperature of 200°C. The procedure was the same except for the following. The specific gravity of the resulting mixture was 0.95 (15/4°C), the refractive index n ²⁰ _D 1.5066, the kinematic viscosity 83 cSt (40°C),
It was 7.5cSt (100℃). The traction coefficient of this material was measured over a temperature range of 60°C to 140°C, and the results are shown in Figure 2.

[Brief explanation of drawings]

FIGS. 1 and 2 are graphs showing the relationship between the traction coefficient and temperature of the compounds obtained in Examples.

Claims (1)

[Claims] 1. A method for producing a synthetic lubricating oil represented by the following formula (), which comprises hydrogenating a compound represented by the following formula () or () in the presence of a ruthenium or rhodium catalyst. . (Here, X ¹ is either [Formula] [Formula] [Formula] [Formula], and R is an alkylene group having 1 to 5 carbon atoms.) (Here, X ² is [Formula] or [Formula], and R is an alkylene group having 1 to 5 carbon atoms.)