JPH0218718B2 - - 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. We have discovered that this compound has a much higher traction coefficient at high temperatures than these known compounds.

These compounds are produced by subjecting naphthalene or tetralin or their derivatives to a Friedel-Crafts reaction with styrene or vinylcyclohexane or their derivatives, alkenyl halides, alkyl dihalides, or aldehydes, and then reacting with hydrogen in the presence of a suitable catalyst such as a nickel catalyst. However, as a result of repeated research, the present inventors have found that when using a nickel catalyst, a higher traction coefficient can be obtained by conducting the hydrogenation reaction at a relatively low temperature. Based on this finding, we have completed the present invention.

The present invention is directed to hydrogenating a compound represented by the following formula () or () using a nickel catalyst to produce a synthetic lubricating oil.
This is a method for producing a synthetic lubricating oil represented by the following formula (), characterized in that it is carried out at a temperature of 80 to 170°C.

(Here, X ¹ is C ₅ ~ having at least one saturated or unsaturated fused or non-fused ring
A _C20 alkyl group, ^R1 , ^R2 , ^R3 , and ^R4 are _C1 to _C4 alkyl groups, and k, m, and n are integers of 1 to 3. ) ₍ ^where _, ^{_ _} _{_ _}
It is an integer of ~3. ) The compound represented by the above formula () or () is a derivative of tetralin or naphthalene, and specific examples include 1,1-ditetralylethane, 1,2-ditetralyl-2-methylpropane, 1-tetralyl-1 -Phenylethane, 1-
naphthyl-1-phenylethane, 2-tetralyl-2-phenylpropane, 1-methylnaphthyl-
2-phenylethane, 1-dimethylnaphthyl-1
-Phenylethane, etc. can be mentioned.

Next, the compound represented by the above formula () is prepared by heating the compound represented by the above formula () or () at 80 to 170°C, preferably at 100 to 170°C, in the presence of a nickel catalyst.
It can be produced by hydrogenation at a temperature of 160°C. Incidentally, nickel catalysts supported on diatomaceous earth or Raney type catalysts are usually used, but there are various forms of use thereof. In addition, the hydrogenation reaction is 1 to 100 Kg/cm ² , preferably 5 to 30 Kg/cm ²
carried out under pressure.

Specific examples of the compound represented by formula () are shown below.

formula 1-decaryl-2-cyclohexylethane, represented by the formula 1,1-didekarylethane, represented by the formula 2-Methyl-1,2-didekarylpropane, represented by the formula 1,2′-bisdecalin, represented by the formula 2-decaryl-2-cyclohexylpropane, 1-dimethyldecaryl-1-cyclohexylethane, 1-Methyldecaryl-1-cyclohexylethane The compound represented by the above formula () obtained by the method of the present invention has a higher traction coefficient than that produced by the conventional method, and is used for traction drives. Excellent as a fluid.
The reason for this is thought to be that many decalin rings are in the cis form (meaning that the hydrogens attached to the carbons at the 9 and 10 positions are in the cis position).

The compound of the above formula () 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 . When measuring, by heating the oil tank with a heater,
The oil temperature was varied from 60°C to 140°C.

Example 1 1000 g of tetralin and 300 g of concentrated sulfuric acid were placed in the glass flask of 3, and the temperature inside the flask was cooled to 0° C. in a long bath. Next, 400 g of styrene was slowly added dropwise into the mixture over 3 hours while stirring, and the reaction was completed by further stirring for 1 hour. after that,
Stirring was stopped and the mixture was allowed to stand to separate the oil layer. This oil layer was washed three times each with 500 cc of 1N aqueous sodium hydroxide solution and 500 cc of saturated brine, and then dried over anhydrous sodium sulfate. Next, unreacted tetralin was removed by distillation, and then vacuum distillation was performed to obtain 750g of a fraction with a boiling point of 135-148℃/0.17mmHg.
I got it. As a result of analyzing this fraction, it was confirmed that it was a mixture of 1-(1-tetralyl)-1-phenylethane and 1-(2-tetralyl)-1-phenylethane.

Next, 500 c.c. of the above fraction was put into an autoclave No. 1, and 15 g of an activated nickel catalyst for hydrogenation (manufactured by JGC Chemical Co., Ltd., trade name N-113 catalyst) was added, and the hydrogen pressure was 20 kg/ Hydrogenation was carried out for 4 hours under conditions of cm ² and reaction temperature of 150°C. After cooling, the reaction solution was filtered to separate the catalyst. Subsequently, after stripping the light components from the liquid, analysis revealed that the hydrogenation rate was 99.9% or more, and this product was found to be 1-(1-decalyl)-1-cyclohexylethane and 1-(2-decalyl)-1-cyclohexylethane.
It was confirmed that it was a mixture of (decalyl)-1-cyclohexylethane. The specific gravity of the resulting mixture was 0.94 (15/4°C), and the kinematic viscosity was 32 cSt (40
℃), 4.4cSt (100℃), and the refractive index n ²⁰ _D is
1.5032, and the content of cis isomer was 63%. In addition,
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 1.

Example 2 3960 g of tetralin and 100 g of anhydrous aluminum chloride were placed in the glass flask of Example 2, 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 g of water in the flask.
cc to decompose the aluminum chloride and separate the oil layer.
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.

Put 500 c.c. of this into an autoclave and activate the hydrogenation nickel catalyst (JGC Chemical Co., Ltd.).
15g of N-113 Catalyst (manufactured by Manufacturer, Inc., trade name: N-113 Catalyst) was added thereto, and hydrogenation was carried out at a hydrogen pressure of 20 kg/cm ² and a reaction temperature of 160°C.
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 more, and this product was found to contain dimerized hydrogenated products such as 1,2'-bisdecalin and 1,1'-bisdecalin, as well as 1-decalyl-4- Ring-opening dimerized hydrogenated product such as cyclohexylbutane 1:2 (mole ratio)
The main component is a mixture of 2 and 2 as a minor component.
- It was confirmed that it contained methyl-1,2-decarylpropanes. The specific gravity of this thing is 0.95 (15/4
℃), kinematic viscosity 68cSt (40℃), 6.4cSt (100℃)
°C), and the refractive index n ²⁰ _D was 1.5096.

The traction coefficient of this thing is from 60℃ to 140℃
Figure 2 shows the results of measurements over a temperature range of .

Comparative Example 1 1-(1-naphthyl)-1-phenylethane and 1-(2-naphthyl) were prepared in the same manner as in Example 1 except that 1000 g of naphthalene and 3000 c.c. of carbon tetrachloride were used instead of 1000 g of tetralin. A mixture of -1-phenylethane was obtained.

The same procedure was followed except that this product was hydrogenated at a hydrogen pressure of 100 Kg/cm ² and a reaction temperature of 250°C. As a result, the specific gravity of the obtained mixture was 0.93 (15/4℃), the kinematic viscosity was 27cSt (40℃), 4.0cSt (100℃), the refractive index n ²⁰ _D was 1.5020, and the content of cis isomer was It was 35%.

Figure 1 shows the traction coefficient measured for this product over a temperature range of 60°C to 140°C.

Comparative Example 2 In Example 1, the hydrogenation treatment was carried out using a nickel catalyst of 50%
The same procedure was followed except that the reaction temperature was 200° C., hydrogen pressure 50 Kg/cm ² and reaction temperature 200° C.

The specific gravity of the resulting mixture was 0.94 (15/4 °C), the kinematic viscosity was 29 cSt (40 °C), 4.2 cSt (100 °C), the refractive index n ²⁰ _D was 1.5025, and the content of cis isomer was 42%. Ta.

Figure 1 shows the traction coefficient measured for this product over a temperature range of 60°C to 140°C.

Comparative Example 3 In Example 2, the hydrogenation treatment was performed using a nickel catalyst 50
The same procedure was followed except that the reaction temperature was 200° C., hydrogen pressure 50 Kg/cm ² and reaction temperature 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 2 shows the results of measurements over a temperature range up to

[Brief explanation of drawings]

Figures 1 and 2 are graphs showing the relationship between the traction coefficient and temperature of the products obtained in Examples and Comparative Examples.

Claims (1)

[Claims] 1. In producing a synthetic lubricating oil by hydrogenating a compound represented by the following formula () or () using a nickel catalyst, the hydrogenation reaction is carried out at a rate of 80 to 170%.
A method for producing synthetic lubricating oil represented by the following formula (), characterized in that it is carried out at a temperature of °C. (Here, X ¹ is C ₅ ~ having at least one saturated or unsaturated fused or non-fused ring
A _C20 alkyl group, ^R1 , ^R2 , ^R3 , and ^R4 are _C1 to _C4 alkyl groups, and k, m, and n are integers of 1 to 3. ) ₍ ^where _, ^{_ _} _{_ _}
It is an integer of ~3. )