JPH0531914B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a traction drive fluid;
More specifically, the present invention relates to a traction drive fluid that has low viscosity and exhibits excellent traction performance over a wide temperature range from low to high temperatures.

[Problems to be solved by conventional technology and invention]

In general, traction drive fluid is a fluid used in traction drive devices (friction drive devices using rolling contact), such as continuously variable transmissions for automobiles, continuously variable transmissions for industrial use, and hydraulic equipment, and has a high traction coefficient and Stability against heat and oxidation, economy, etc. are required.

In recent years, research has been focused on reducing the size and weight of traction drive devices, mainly for automotive applications, and along with this, the traction drive fluid used in these traction drive devices has also been developed to reduce the size and weight of traction drive devices, which can be used under various harsh conditions. Stably high performance over a wide temperature range from low to high temperatures (approximately -30 to 140℃) (high traction coefficient, low viscosity, excellent thermal and oxidation stability) They are required to be able to demonstrate their abilities (e.g.,

However, until now, Tokuko Publication No. 46-338,
Various traction drive fluids have been developed, including Japanese Patent Publication No. 46-339, but none of them can satisfy the above-mentioned required characteristics.
Various problems arose. For example, a compound that exhibits a high traction coefficient at high temperatures has a high viscosity and a large stirring loss, resulting in low transmission efficiency and also has problems in low-temperature startability. On the other hand, compounds with low viscosity and excellent transmission efficiency have a low traction coefficient at high temperatures, and their viscosity decreases too much at high temperatures, causing problems with the lubrication of traction transmission devices.

[Means to solve the problem]

Therefore, the present inventors have conducted extensive research in order to solve the above problems and develop a traction drive fluid that has low viscosity and excellent performance over a wide temperature range from low to high temperatures.

As a result, it was found that dimerized hydrogenated products of cyclic monoterpenoids have the desired traction performance. The present invention was completed based on this knowledge.

That is, the present invention provides a traction drive fluid characterized by containing a dimerized hydrogenated product of cyclic monoterpenoids,
Cyclic monoterpenoids are dimerized and further hydrogenated to be used as a traction drive fluid.

There are various types of cyclic monoterpenoids, and preferred examples include menthadienes, pinenes, bicyclo[2.2.1]heptanes, and mixtures thereof.

Here, menthadiene has a basic skeleton of 1, 2, 1, 3 or 1, 4 of the cyclohexane ring.
It has two carbon-carbon double bonds in a structure in which a methyl group and an isopropyl group are substituted at each position. Specifically, limonene; isolimonene; α-, β-, γ-terpinene ; α-, β-phellandrene; terpinolene; silvestrene, and the like. Further, these compounds can be substituted with an alkyl group or a hydroxyl group, but it is preferable to use unsubstituted menthadienes. Moreover, a mixture of two or more of these can also be used.

Pinenes include α-pinene (d-form, l-form, dl
), β-pinene (d-form, l-form), δ-pinene (d
(l-isomer, l-isomer), orthodene, etc. Furthermore, these compounds can be substituted with alkyl groups, hydroxyl groups, etc., but
It is preferable to use unsubstituted pinenes. Moreover, a mixture of two or more of these can also be used.

The above bicyclo[2.2.1]heptanes include camphene (d-form, l-form, dl-form), bornylene (d-form,
l-form), α-fenthiene (d-form, l-form, dl-form),
β-Fentien (d-form, DL-form), γ-Fentien, δ-Fentien, ε-Fentien, ζ
-Fuentien, borneol (d-form, l-form, dl
), π-borneol (d-form, l-form), ω-borneol, isoborneol (d-form, l-form, dl
camphuene hydrate), α-phentyl alcohol (d-form, l-form, dl-form), β-phentyl alcohol (d-form, l-form, dl-form), α-isophentyl alcohol (d-form, Examples include l-isomer, dl-isomer), β-isophenthyl alcohol (d-isomer, l-isomer, dl-isomer), and compounds having various substituents such as alkyl groups introduced into these compounds can also be used.
Moreover, a mixture of two or more of these can also be used.

Incidentally, the dimerization of cyclic monoterpenoids in the present invention means either or both of dimerization of the same type of cyclic monoterpenoids and co-dimerization of different types of cyclic monoterpenoids.

The dimerization of the above-mentioned cyclic monoterpenoids is usually carried out in the presence of a catalyst by adding a solvent and a reaction regulator as necessary.

Various catalysts can be used for the dimerization of cyclic monoterpenoids, but
Generally, acidic catalysts are used. Specifically, white earths such as activated clay and acid clay, mineral acids such as sulfuric acid, hydrochloric acid, and hydrofluoric acid, organic acids such as p-toluenesulfonic acid and triflic acid, aluminum chloride, ferric chloride, and chloride. Lewis acids such as stannic, boron trifluoride, boron tribromide, aluminum bromide, gallium chloride, and gallium bromide, as well as solid acids such as zeolite, silica, alumina, silica/alumina, cation exchange resins, and heteropolyacids. Various materials can be used, but they may be selected appropriately taking into consideration ease of handling, economical efficiency, etc. Also, the amount used is
Although there is no particular restriction, it is usually 0.1 to 100% by weight, preferably 1 to 1% by weight based on the cyclic monoterpenoids.
It is in the range of 20% by weight.

When dimerizing cyclic monoterpenoids, a solvent is not necessarily required, but it is preferably used for handling the cyclic monoterpenoids and catalyst during the reaction or for controlling the progress of the reaction. Such solvents include n-pentane,
Most saturated hydrocarbons such as n-hexane, heptane, octane, nonane, decane, cyclopentane, cyclohexane, methylcyclohexane, decalin, etc. can be used. In this case, aromatic hydrocarbons such as benzene, toluene, and xylene, and tetralin can also be used.

In addition, the reaction regulator is used to cause the cyclic monoterpenoids to undergo an appropriate reaction, especially to increase the selectivity of the dimerization reaction.
Carboxylic acids such as acetic acid, acid anhydrides such as acetic anhydride and phthalic anhydride, cyclic esters such as γ-butyrolactone and valerolactone, glycols such as ethylene glycol, mononitro compounds such as nitromethane and nitrobenzene, ethyl acetate, etc. Various substances can be used, such as esters, ketones such as mesityl oxide, aldehydes such as formalin and acetaldehyde, cellosolves, and polyalkylene glycol alkyl ethers such as diethylene glycol monoethyl ether. There are no particular restrictions on the amount of reaction modifier used, but it is usually
It ranges from 0.1 to 20% by weight.

The dimerization reaction is carried out in the presence of these catalysts, etc.
The reaction conditions are generally set within a temperature range of -30°C to 180°C depending on the type of catalyst, additives, etc. For example, when the catalyst is white earth or zeolite, the reaction temperature is from room temperature to 180°C, preferably 60°C or higher, and when other catalysts are used -
It is carried out at a temperature of 30°C to 100°C, preferably 0°C to 60°C.
In addition, when the cyclic monoterpenoid as a raw material is an alcohol, dimerization involves a dehydration dimerization reaction.

Next, the thus obtained dimer of cyclic monoterpenoids is hydrogenated to obtain the desired dimerized hydrogenated product. Hydrogenation may be performed on the entire amount of the dimerized product, or may be performed by fractionating or fractionating a portion thereof.

Like dimerization, this hydrogenation is usually carried out in the presence of a catalyst, and the catalyst may include metals such as nickel, ruthenium, palladium, platinum, rhodium, iridium, copper, chromium, molybdenum, cobalt, and tungsten. One or more types of catalysts known as hydrogenation catalysts can be used. The amount of this catalyst added is in the range of 0.1 to 100% by weight, preferably 1 to 10% by weight, based on the above polymer.

Also, like the dimerization, this hydrogenation proceeds without a solvent, but a solvent can also be used.
In that case, the types of solvent include n-pentane,
Most liquid saturated hydrocarbons such as n-hexane, heptane, octane, nonane, decane, dodecane, cyclopentane, cyclohexane, methylcyclohexane, etc. can be used. Furthermore, liquids such as aromatics, olefins, alcohols, ketones, and ethers can be used, but saturated hydrocarbons are particularly preferred.

The reaction temperature is usually room temperature to 300°C, preferably
The temperature is 40 to 200℃, and the reaction pressure is from normal pressure to 200Kg/
It can be carried out at a pressure of cm ² G, preferably in the range of normal pressure to 100 kg/cm ² G, and can be carried out in the same manner as general hydrogenation.

The dimerized hydrogenated product of cyclic monoterpenoids thus produced may be used alone, or may be used in combination with other traction drive fluids if necessary. In this case, the amount of the dimerized hydrogenated compound is not particularly limited, and may be selected as appropriate depending on the type of the dimerized hydrogenated compound and the type of other traction drive fluid to be mixed.
It is usually desirable to contain at least 5% by weight of the total traction fluid, preferably at least 30% by weight of the dimerized hydrogenate.

Note that other traction drive fluids to be mixed with the dimerized hydrogenated product of cyclic monoterpenoids include those that have been conventionally used as traction drive fluids, as well as those that have poor traction performance when used alone and have not been put to practical use. There are various things that can be mentioned, such as oil. For example, a wide range of liquid substances can be used, such as mineral oils such as paraffinic mineral oils, naphthenic mineral oils, and intermediate mineral oils, alkylbenzenes, polybutenes, polyα-olefins, synthetic naphthenes, esters, and ethers. Among them, alkylbenzenes, polybutenes, and synthetic naphthenes are preferred. Here, the synthetic naphthenes include alkane derivatives having two or more cyclohexane rings, alkane derivatives having one or more decalin rings and one or more cyclohexane rings, alkane derivatives having two or more decalin rings, cyclohexane rings or decalin rings. There are compounds that have a structure in which two or more are directly bonded. Specific examples of such synthetic naphthenes include 1-cyclohexyl-1-decarylethane; 1,3-dicyclohexyl-3-methylbutane; 2,4-dicyclohexylpentane; 1,2-bis(methylcyclohexyl)-2-methylpropane. ;1,1-
Bis(methylcyclohexyl)-2-methylpropane; 2,4-dicyclohexyl-2-methylpentane and the like can be mentioned.

The traction drive fluid of the present invention contains a dimerized hydrogenated product of cyclic monoterpenoids as an essential component, and is prepared by optionally blending other liquids (traction drive fluid). In addition, antioxidants, rust inhibitors,
Appropriate amounts of various additives such as detergent dispersants, pour point depressants, viscosity index improvers, extreme pressure agents, anti-wear additives, anti-fatigue agents, antifoaming agents, oiliness improvers, and colorants can be used. can.

〔Example〕

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

Example 1 A stirrer, a thermometer, a dropping funnel, and a Dimroth reflux condenser were attached to the four-necked flask in Example 1, and 300 ml of methylcyclohexane was used as a solvent, and 10 g of activated clay (Galleon Earth NS, manufactured by Mizusawa Chemical Co., Ltd.) was used as a catalyst. I prepared it. After heating and stirring in an oil bath to bring the temperature to 85℃, dipentene (dl-
limonene) was added dropwise over 1 hour while stirring. Thereafter, the reaction was allowed to continue for 8 hours at 85°C while stirring. After cooling, the catalyst was filtered through a filter paper, and the solvent and unreacted raw materials were recovered using a rotary evaporator to obtain 650 g of the remaining reaction liquid.

650 g of this reaction solution and 10 g of a nickel catalyst for hydrogenation (manufactured by JGC Chemical Co., Ltd.: N-113) were placed in one autoclave, and hydrogenation was performed at a hydrogen pressure of 50 Kg/cm ² G and a reaction temperature of 150°C for 3 hours. Ivy. After cooling, the catalyst was filtered and analyzed, and the hydrogenation rate was 99% or more.

This hydrogenated product is distilled under reduced pressure and has a boiling point of 110-122℃/
400 g of a 0.2 mmHg fraction was obtained. The molecular weight of this fraction was measured using a gas chromatography-mass spectrometer (GC).
-MS) analysis revealed that they were all compounds with 20 carbon atoms (dimerized hydrogenated products of dipentene (dl-limonene)).

The properties of this product were as follows.

Kinematic viscosity 33.05cSt (40℃) 3.825cSt (100℃) Viscosity index -185 Specific gravity (15/4℃) 0.9109 Pour point -22.5℃ Refractive index (n ²⁰ _D ) 1.4931 Furthermore, the traction coefficient of this product is set to 60℃
Measurements were made in the temperature range from to 140℃. The results are shown in FIG.

Example 2 Cyclohexane was added as a solvent to a 4-necked flask equipped with the same equipment as in Example 1.
300 ml, and 10 g of activated clay (Galleon Earth NS, manufactured by Mizusawa Chemical Co., Ltd.) was charged as a catalyst. β− at room temperature
1000 g of pinene was added dropwise over 4 hours while stirring. Thereafter, the reaction was allowed to continue for 30 minutes while stirring. Next, the catalyst was filtered through a filter paper, and the solvent and unreacted raw materials were recovered using a rotary evaporator to obtain 800 g of the remaining reaction liquid.

700 g of this reaction solution and 10 g of a nickel catalyst for hydrogenation (manufactured by JGC Chemical Co., Ltd.: N-113) were placed in one autoclave, and hydrogenation was performed at a hydrogen pressure of 50 Kg/cm ² G and a reaction temperature of 100°C for 3 hours. Ivy. After cooling, the catalyst was filtered and analyzed, and the hydrogenation rate was 99% or more.

This hydrogenated product is distilled under reduced pressure and has a boiling point of 108-120℃/
200 g of a 0.2 mmHg fraction was obtained. The molecular weight of this fraction was measured using a gas chromatography-mass spectrometer (GC).
- MS) analysis shows that the number of carbon atoms in all of them is 20g.
The compound group (dimerized hydrogenated products of β-pinene) was found to be the following.

The properties of this product were as follows.

Kinematic viscosity 32.53cSt (40℃) 3.978cSt (100℃) Viscosity index −133 Specific gravity (15/4℃) 0.9273 Pour point −27.5℃ Refractive index (n ²⁰ _D ) 1.4974 Furthermore, the traction coefficient of this product is set to 60℃
Measurements were made in the temperature range from to 140℃. The results are shown in FIG.

Example 3 300 ml of methylcyclohexane was added as a solvent, and activated clay (Mizusawa Chemical Co., Ltd.) was added as a catalyst to a four-necked flask equipped with the same equipment as in Example 1.
Manufacturer: Galleon Earth NS) 10g was charged. After heating and stirring in an oil bath to 80℃, turpentine (93% α-pinene, 3% β-pinene, 4% other
%) was added dropwise over 4 hours while stirring. Thereafter, the reaction was allowed to continue for 4 hours at 80° C. while stirring. After cooling, the catalyst was filtered through a filter paper, and the solvent and unreacted raw materials were recovered using a rotary evaporator to obtain 700 g of the remaining reaction liquid.

700 g of this reaction solution and 10 g of a nickel catalyst for hydrogenation (manufactured by JGC Chemical Co., Ltd.: N-113) were placed in one autoclave, and hydrogenation was performed at a hydrogen pressure of 50 Kg/cm ² G and a reaction temperature of 100°C for 3 hours. Ivy. After cooling, the catalyst was filtered and analyzed, and the hydrogenation rate was 99% or more.

This hydrogenated product is distilled under reduced pressure and has a boiling point of 108-120℃/
200 g of a 0.2 mmHg fraction was obtained. The molecular weight of this fraction was measured using a gas chromatography-mass spectrometer (GC).
-MS) analysis revealed that they were all compounds with 20 carbon atoms (dimerized hydrogenated products of turpentine oil).

The properties of this product were as follows.

Kinematic viscosity 33.21cSt (40℃) 3.996cSt (100℃) Viscosity index −133 Specific gravity (15/4℃) 0.9276 Pour point −27.5℃ Refractive index (n ²⁰ _D ) 1.4977 Furthermore, the traction coefficient of this product is set to 60℃
Measurements were made in the temperature range from to 140℃. The results are shown in FIG.

Example 4 300 ml of methylcyclohexane was added as a solvent, and activated clay (Mizusawa Chemical Co., Ltd.) was added as a catalyst to a four-necked flask equipped with the same equipment as in Example 1.
150 g (manufactured by Galleon Earth NS) and 593.10 g of camphuen as a raw material were charged. The mixture was heated and stirred in an oil bath, and reacted at 120°C for 10 hours.
After cooling to room temperature, the catalyst was filtered, and the solvent and unreacted raw materials were recovered using a rotary evaporator to obtain 345.50 g of the remaining reaction liquid. This is distilled under reduced pressure to obtain a fraction with a boiling point range of 126-134℃/0.2mmHg.
221.10g was obtained. As a result of analysis, this substance was found to be a dimer of camphene (98% purity).

Subsequently, 220 g of this fraction and 10 g of a nickel catalyst for hydrogenation (manufactured by JGC Chemical Co., Ltd.: N-113) were placed in one autoclave, and the hydrogen pressure was 60 Kg/cm ² G and the reaction temperature was
Hydrogenation was carried out at 140°C for 4 hours. After cooling,
When the catalyst was filtered and analyzed, the hydrogenation rate was 99%.
That's all.

The properties of this hydrogenated product were as follows.

Kinematic viscosity 55.52cSt (40℃) 5.793cSt (100℃) Viscosity index -7 Specific gravity (15/4℃) 0.9453 Refractive index (n ²⁰ _D ) 1.5004 Furthermore, the traction coefficient of this product is set at 40℃
Measurements were made in the temperature range from to 140℃. The results are shown in FIG.

Example 5 300 ml of methylcyclohexane was added as a solvent, and activated clay (Mizusawa Chemical Co., Ltd.) was added as a catalyst to a four-necked flask equipped with the same equipment as in Example 1.
Manufacturer: Galleon Earth NS) 50g was charged. After stirring and heating in an oil bath to 90℃,
Gum turpentine oil (92% α-pinene, 5% β-pinene
%, other 3%) and 500 g of dipentene (DL-limonene) was added dropwise over 2 hours with stirring. Thereafter, the reaction was allowed to continue for 7 hours at 110°C while stirring. After cooling, the catalyst was filtered through a filter paper, and the solvent and unreacted raw materials were recovered using a rotary evaporator to obtain 600 g of the remaining reaction liquid.

600 g of this reaction solution and 10 g of nickel catalyst for hydrogenation (manufactured by JGC Chemical Co., Ltd.: N-113) were placed in autoclave 1, hydrogen pressure was 50 Kg/cm ² G, and reaction temperature was 150°C.
Hydrogenation was carried out for 3 hours. After cooling, the catalyst was filtered and analyzed, and the hydrogenation rate was 99% or more.

This hydrogenated product is distilled under reduced pressure and has a boiling point of 105-125℃/
380 g of a 0.15 mmHg fraction was obtained.

The properties of this product were as follows.

Kinematic viscosity 35.61cSt (40℃) 4.089cSt (100℃) Viscosity index -152 Specific gravity (15/4℃) 0.9241 Refractive index (n ²⁰ _D ) 1.4959 Furthermore, the traction coefficient of this product was adjusted to 60℃
Measurements were made in the temperature range from to 140℃. The results are shown in FIG.

Example 6 Into a four-necked flask 2 equipped with the same equipment as in Example 1, 300 ml of methylcyclohexane was used as a solvent, and activated clay (dried at 120°C for 8 hours) as a catalyst (manufactured by Mizusawa Chemical Co., Ltd.: galleon earth
NS) 130g was prepared. Gum turpentine oil (92% α-pinene, 5% β-pinene, 3% other) at room temperature.
500 g was added dropwise over 2 hours while stirring.
After dropping, the temperature had reached 75°C. Thereafter, the reaction was allowed to continue for 2 hours while stirring. The temperature had returned to room temperature. Next, the catalyst was filtered through a filter paper, and the solvent and unreacted raw materials were recovered using a rotary evaporator to obtain 425 g of the remaining reaction liquid.

420 g of this reaction solution and 20 g of a ruthenium-carbon catalyst for hydrogenation (manufactured by Nippon Engelhard Co., Ltd.) were mixed into 1
The mixture was placed in an autoclave and hydrogenated at a hydrogen pressure of 50 kg/cm ² G and a reaction temperature of 50° C. for 6 hours. After cooling, the catalyst was filtered and analyzed, and the hydrogenation rate was found to be
It was over 99%.

This hydrogenated product is distilled under reduced pressure and has a boiling point of 132-144℃/
150 g of a 0.4 mmHg fraction was obtained. The molecular weight of this fraction was measured using a gas chromatography-mass spectrometer (GC).
-MS) analysis revealed that they were all compounds with 20 carbon atoms (dimerized hydrogenated products of turpentine oil).

The properties of this product were as follows.

Kinematic viscosity 36.53cSt (40℃) 4.201cSt (100℃) Viscosity index -133 Specific gravity (15/4℃) 0.9390 Pour point -25.0℃ Refractive index (n ²⁰ _D ) 1.5039 Furthermore, the traction coefficient of this product is set to 60℃
Measurements were made in the temperature range from to 140℃. The results are shown in FIG.

Example 7 Into a four-necked flask 2 equipped with the same equipment as in Example 1, 200 ml of ethylcyclohexane was added as a solvent, and activated clay (dried at 120°C for 8 hours) as a catalyst (manufactured by Mizusawa Chemical Co., Ltd.). galleon earth
NS) 50g was prepared. Gum turpentine oil (92% α-pinene, 5% β-pinene, 3% other) at room temperature.
A mixture of 263.87 g and 283.71 g of camphuene was added dropwise over 3 hours with stirring. 3 hours after that
The reaction was carried out at 115° C. with continued stirring. After cooling, the catalyst was filtered through a filter paper, and the solvent and unreacted raw materials were recovered using a rotary evaporator to obtain 410 g of the remaining reaction liquid.

400 g of this reaction solution and 20 g of a ruthenium-carbon catalyst for hydrogenation (manufactured by Nippon Engelhard Co., Ltd.) were mixed into 1
The mixture was placed in an autoclave and hydrogenated at a hydrogen pressure of 50 kg/cm ² G and a reaction temperature of 50° C. for 6 hours. After cooling, the catalyst was filtered and analyzed, and the hydrogenation rate was found to be
It was over 99%.

This hydrogenated product is distilled under reduced pressure and has a boiling point of 135-141℃/
120 g of a 0.4 mmHg fraction was obtained.

The properties of this product were as follows.

Kinematic viscosity 40.01cSt (40℃) 4.641cSt (100℃) Viscosity index −65 Specific gravity (15/4℃) 0.9434 Pour point −27.5℃ Refractive index (n ²⁰ _D ) 1.5042 Furthermore, the traction coefficient of this product is set to 60℃
Measurements were made in the temperature range from to 140℃. The results are shown in FIG.

Example 8 Ethylcyclohexane was added as a solvent to a four-necked flask equipped with the same equipment as in Example 1, except that a Dean-Stark type water removal device was installed below the Dimroth reflux condenser.
300ml, activated clay (dried at 120℃ for 8 hours) as a catalyst (Galleon Earth NS, manufactured by Mizusawa Chemical Co., Ltd.)
150g and isoborneol as raw material 526.10
g were prepared respectively. The reaction mixture was heated and stirred in an oil bath for 10 hours while removing generated water at 133°C. After cooling to room temperature, the catalyst was filtered, and the solvent and unreacted raw materials were recovered using a rotary evaporator to obtain 326.30 g of the remaining reaction liquid. This is distilled under reduced pressure and the boiling point range is 125-138℃/0.2mm.
200.50 g of Hg fraction was obtained. Analysis revealed that this substance was a dimer of camphene (98% purity) produced by dehydration of isoborneol.

Subsequently, 180 g of this fraction and 10 g of a nickel catalyst for hydrogenation (manufactured by JGC Chemical Co., Ltd.: N-113) were placed in one autoclave, and the hydrogen pressure was 60 Kg/cm ² G and the reaction temperature was
Hydrogenation was carried out at 140°C for 4 hours. After cooling,
When the catalyst was filtered and analyzed, the hydrogenation rate was 99%.
That's all.

The properties of this hydrogenated product were as follows.

Kinematic viscosity 56.53cSt (40℃) 5.801cSt (100℃) Viscosity index -12 Specific gravity (15/4℃) 0.9459 Refractive index (n ²⁰ _D ) 1.5010 Furthermore, the traction coefficient of this product is set at 40℃
Measurements were made in the temperature range from to 140℃. The results are shown in FIG.

Comparative Example 1 1000 g of α-methylstyrene, 50 g of acid clay, and 50 g of ethylene glycol were placed in a 2-four-necked flask equipped with the same equipment as in Example 1, and reacted with stirring at 140° C. for 2 hours. After filtering the catalyst from the reaction solution, unreacted α-methylstyrene and ethylene glycol were distilled off, and the boiling point
900g of fraction at 125-130°C/0.2mmHg was obtained. As a result of nuclear magnetic resonance (NMR) analysis and gas chromatography analysis, this fraction was confirmed to be a mixture of 95% linear dimer and 5% cyclic dimer of α-methylstyrene.

500 ml of this fraction was hydrogenated in the same manner as in Example 1 except that the reaction temperature was 200°C to obtain a traction drive fluid containing 2,4-dicyclohexyl-2-methylpentane as the main component. Ta.

The properties of this product were as follows.

Kinematic viscosity 20.27 cSt (40°C) 3.580 cSt (100°C) Viscosity index 13 Pour point -35°C or less Furthermore, as in Example 1, the traction coefficient of this product was measured in the temperature range from 60°C to 140°C. The results are shown in Figures 1, 2 and 4.

Comparative Example 2 In a 4-necked flask equipped with the same equipment as in Example 1, 500 ml of methylcyclohexane was added as a solvent, and 156.0 ml of isoborneol was added as a raw material.
g and 184.01 g of triethylamine were charged.
While stirring at room temperature, 146.84 g of cyclohexane carbonyl chloride was added to 100 g of methylcyclohexane.
ml solution was added dropwise over 4 hours. Thereafter, the reaction was carried out at 60°C for 2 hours to complete the reaction.

Next, the mixture was cooled to room temperature, the precipitated triethylamine hydrochloride was filtered off, and the solvent and unreacted raw materials were recovered using a rotary evaporator to obtain 252.51 g of the remaining reaction liquid. This was distilled under reduced pressure to obtain a fraction of 196.48 with a boiling point range of 121-131℃/0.2mmHg.
I got g. When this fraction was analyzed by nuclear magnetic resonance spectroscopy (NMR), infrared absorption spectroscopy (IR), gas chromatography-mass spectrometry (GC-MS), and hydrogen flame (FID) gas chromatography (GC), it was found that Bornyl cyclohexane carboxylate was found to be 99%.

The properties of this product were as follows.

Kinematic viscosity 24.04cSt (40℃) 3.966cSt (100℃) Viscosity index 16 Specific gravity (15/4℃) 1.0062 Refractive index (n ²⁰ _D ) 1.4860 Furthermore, the traction coefficient of this product is set at 40℃
Measurements were made in the temperature range from to 140℃. The results are shown in FIG.

The traction coefficients in the above Examples and Comparative Examples were measured using a two-cylinder friction tester. In other words, the adjacent cylinders of the same size (diameter 52 mm, thickness 6 mm, driven side has a radius of curvature of 10
mm Tyco type, the drive side is a flat type without crowning), one side is rotated at a constant speed (1500 rpm) and the other is rotated continuously from 1500 rpm to 1750 rpm.
A load of 7 kg was applied by a spring to the contact portion of both cylinders, and the tangential force generated between the two cylinders, that is, the traction force, was measured to determine the traction coefficient. This cylinder is made of bearing steel SUJ-2 with a mirror finish.
The maximum Hertzian contact pressure was 112 Kgf/mm ² .

In addition, when measuring the relationship between traction coefficient and oil temperature, the oil temperature was varied from 40℃ to 140℃ by heating the oil tank with a heater.
This is a plot of the relationship between traction coefficient and oil temperature at a slip rate of 5%.

As is clear from FIGS. 1 to 4, the traction drive fluid of the present invention can maintain a high traction coefficient, particularly in a high temperature range, and is suitable as a traction drive fluid.

〔Effect of the invention〕

The traction drive fluid of the present invention containing such dimerized hydrogenated cyclic monoterpenoids has a high traction coefficient over a wide temperature range from room temperature to high temperature, and improves transmission efficiency. As a result, it is possible to reduce the size and weight of the traction drive device, extend its lifespan, and increase its output, which can be widely used in various mechanical products such as continuously variable transmissions for automobiles and industrial use, and even hydraulic equipment. .

[Brief explanation of the drawing]

1 to 4 are graphs showing temperature changes in traction coefficients of traction drive fluids obtained in Examples and Comparative Examples.

Claims (1)

[Scope of Claims] 1. A traction drive fluid characterized by containing a dimerized hydrogenated product of cyclic monoterpenoids. 2. The traction drive fluid according to claim 1, which contains at least 5% by weight of a dimerized hydrogenated product of cyclic monoterpenoids. 3. The traction drive fluid according to claim 1 or 2, wherein the cyclic monoterpenoids are menthadienes, pinenes, or bicyclo[2.2.1]heptanes.