JPS6242956B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a traction drive.
Regarding fluids for rolling friction drive devices,
More specifically, the present invention relates to a traction drive fluid obtained by hydrogenating an alkylation reaction product of toluene and/or xylene (or a mixture of at least one of these compounds and ethylbenzene) and styrene.

In a traction drive device, rolling contact surfaces (for example, contact surfaces of two cylinders whose side surfaces are in contact and rotate in opposite directions around their respective fixed rotational axes, or By sandwiching the fluid between the contact surfaces of two cones that rotate in opposite directions around a fixed rotation center axis, the oil film of the fluid does not lose its fluidity. The separation is required to restore the fluidity of the fluid body. In other words, in a traction drive device, power is transmitted using the rolling friction generated by the hardening of a fluid oil film on the rolling contact surface (a thin film under high pressure). The fluid used for this purpose is required to have high rolling friction. This required property of a traction drive fluid is expressed by the rolling coefficient of friction measured in a given traction drive device.

Various hydrocarbons and oxygen-containing hydrocarbons have already been proposed as fluids for traction drives, and methods for their production have also been proposed, but it is difficult to synthesize them using inexpensive raw materials that are easily available industrially and through simple operations. There is no known traction drive fluid that is capable of this and also exhibits excellent performance. That is, decalin, perhydroanthracene (USP 3411369), polycyclohexyl (ASLE Transactions 13 105) are used as traction drive fluids.
(1970), USP3925217), bicyclohexyl, dicyclohexylmethane (USP3440894), 2,3
-Dicyclohexylbutane (Japanese Patent Application Laid-open No. 46-4510),
Hydrogenated isobutylene low polymer (Unexamined Japanese Patent Publication 1973-
4766, JP-A-47-2164, JP-A-47-35661, JP-A-47-2229), α-methylstyrene cyclized dimer hydride (JP-A-47-2229, JP-A-47-35763), Adamantane (Special Publication No. 48-42067, Special Publication No. 48-Sho.
42068, Special Publication No. 47-35763) were proposed, but
It is insufficient in practical performance, particularly in terms of rolling friction coefficient, ie, traction coefficient.

As a result of many studies related to this,
A linear dimeric hydride of α-methylstyrene, ie, 2,4-dicyclohexyl-2-methylpentane, has been proposed as a synthetic fluid with a rolling friction coefficient superior to that of the above-mentioned various hydrocarbons (Japanese Patent Application Laid-Open No. 1989-1993-1). 7664, USP3975278, USP3994816).
However, in order to industrially synthesize this traction drive fluid, it is known to linearly dimerize α-methylstyrene and then hydrogenate it, but α-methylstyrene as a raw material is expensive. in,
Moreover, there are drawbacks such as side reactions occurring in the dimerization step. Multimerization and cyclization are well known side reactions in this case, and an improvement proposal is to thermally decompose (depolymerize) the by-produced multimers (trimers to heptamers) into dimers. An attempt was made to convert the conversion (Japanese Patent Publication No. 47-35763), a method of using montmorillonite clay in combination with an organic oxygen-containing compound (Japanese Patent Application Laid-open No. 52-148053), and a method of using pre-heat-treated montmorillonite clay as a catalyst (Japanese Patent Publication No. 1987-1483). Attempts to suppress cyclization are known, such as by methods such as 53-21149), but their effectiveness is not yet complete. Furthermore, even if improvements are made to this side reaction prevention technology in the future, it will still be impossible to avoid the economic burden of having to secure α-methylstyrene as a raw material. The high cost of the traction drive lubricants currently on the market is thought to be the biggest reason for the slow spread of traction drive power transmission devices.
This is considered to be unavoidable at present because, as mentioned above, expensive α-methylstyrene is used as a raw material and there are difficulties in the dimerization process. Naturally, attempts were made to use styrene, which is much cheaper than α-methylstyrene, as a raw material, but the rolling friction coefficient of the product in this case was It has been found that it is about 30% inferior to the
47−35763). In addition, hydrogenation of alkylnaphthalenes, naphthenic mineral oils, hydrogenation of polycondensates of alkylbenzenes and formalin,
Hydrogenation of indane dimer was also considered, but
(Japanese Patent Publication No. 47-35763), its properties are inevitably inferior to 2,4-dicyclohexyl-2-methylpentane obtained by dimerizing α-methylstyrene and then hydrogenating it.

As a result of repeated research into the possibility of producing an excellent traction drive fluid without using α-methylstyrene, the present inventor has determined that xylene and/or toluene may be alkylated with styrene, or xylene and/or toluene may be alkylated with styrene. This objective is achieved by alkylating a mixture of at least one toluene and less than 50% by weight of ethylbenzene with styrene and hydrogenating the fraction with a boiling point between 270 and 340° C. with this alkylated product. The present invention was completed based on the discovery that the present invention is possible. As is well known, xylene or toluene and styrene are relatively inexpensive raw materials that can be easily obtained industrially, but it is known from the above-mentioned conventional patents and various documents that an excellent traction drive fluid can be produced from them. There is no disclosure whatsoever in any of them, and there is also no description that suggests that the product produced by this manufacturing method can be unique in having an excellent rolling friction coefficient.

The present invention is characterized in that xylene and/or toluene is alkylated with styrene, and then the resulting alkylated product is used to hydrogenate the fraction with a boiling point of 270-340°C. As a starting material, xylene is preferred from the viewpoint of the rolling friction coefficient of the final product, and mixed xylenes, which are industrially easily available, are most preferred. The mixed xylene referred to here refers to 10 to 40% by weight of o-xylene and 20% by weight of m-xylene.
-45% by weight, p-xylene 10-25% by weight, and ethylbenzene 0-45% by weight, and the inclusion of less than 50% by weight of ethylbenzene does not impair the effects of the present invention. Ethylbenzene can be used instead of xylene or toluene as a starting material, but there is no particular advantage over using xylene and/or toluene, which are industrially easily available and relatively inexpensive. There is no need to use high-purity xylene and toluene, and even if saturated aliphatic or aromatic hydrocarbons with 12 or less carbon atoms, such as hexane, benzene, and decane, coexist as impurities, there will be no problem. do not have. Styrene, which is an alkylating agent, does not need to be of high purity, and aromatic hydrocarbons or saturated aliphatic hydrocarbons with carbon numbers of 12 or less, such as ethylbenzene, xylene, toluene, decane, and dodecane, coexist. However, there is no problem at all. Also,
Vinyltoluene, α-methylstyrene, p-methylstyrene, etc. can also be used as the alkylating agent, but these do not have any particular advantage over using styrene, which is relatively inexpensive.

Regarding the alkylation method of xylene and/or toluene with styrene, conventionally known techniques can be applied, and it is particularly preferable that the polymerization rate of styrene is 18% or less. Specific examples of alkylation methods are as follows. For example, when using sulfuric acid as a catalyst, add an equal amount or less of sulfuric acid (concentration 75 to 90%) to xylene (or toluene) cooled to 30°C or lower, preferably 5 to 20°C, and stir. While cooling to 30°C or less, styrene, which is less than half the amount of xylene (or toluene), is added in small portions over a period of, for example, 10 minutes to 1 hour, and after the addition is complete, the mixture is further stirred for, for example, 30 minutes to 2 hours. By adding an aqueous sodium hydroxide solution to neutralize the reaction system, and then performing water washing and fractional distillation, the alkylated product fraction of xylene (or toluene) can be obtained with a yield of 82 to 87% relative to styrene. You can get it at a high rate. Also,
It is also possible to use the conventional alkylation method of styrene and xylene (or toluene) using concentrated sulfuric acid as a catalyst. In this case, special attention should be paid to the reaction temperature, styrene addition rate, and stirring of the reaction system to prevent side reactions. It is desirable to suppress this as much as possible and strive to achieve a styrene effective utilization rate of 82% or higher (styrene polymerization rate of 18% or lower). Furthermore, it is also possible to use a well-known solid acid, such as a silica alumina catalyst, as an aromatic alkylation catalyst;
It is preferable to pay attention to the reaction conditions so as to keep the polymerization rate of styrene below the above 18%. For example, a synthetic silica alumina catalyst with an alumina content of 20 to 50 wt%, which has been calcined in advance at 450 to 600°C, is used at a certain temperature. 140-160℃, reaction pressure 3-10Kg/
Preferably, consideration is given to continuously supplying a 5 to 20:1 mixture of xylene (or toluene) and styrene under conditions of cm ² and SV of 0.3 to 3.0.

As described above, by using sulfuric acid or a solid acid as a catalyst and paying attention to the reaction conditions, the polymerization rate of styrene can be suppressed to 7 to 18%. In this case, the styrene polymer is preferably separated from the alkylated product in a fractionation step after alkylation. If the above-mentioned consideration is not given to the alkylation reaction conditions, the amount of styrene high polymer (tar) by-product will increase significantly, and the alkylation product fraction will contain styrene linear dimer and cyclic dimer. This is disadvantageous from the point of view of the quality of the alkylated product as well as the effective utilization of styrene.

To obtain the product corresponding to the alkylation product of xylene (or toluene) with styrene,
A method of treating toluene and methylphenyl carbinol with an aluminum chloride catalyst, 2-phenyl-
Method of decomposing 1,2-di-p-tolylpropanone-1, method of treating α-bromoethylbenzene and toluene with zinc powder, β,β-dichloro-α-
Methods include reducing phenyl-α-p-tolylethane with metallic sodium, treating toluene (or xylene) and vinyl chloride with aluminum chloride, and alkylating styrene and toluene (or xylene) with an aluminum chloride catalyst. As mentioned above, attempts have been made for a long time to alkylate xylene (or toluene) and styrene using sulfuric acid or a solid acid as a catalyst, taking into account the reaction conditions to keep the polymerization rate of styrene below 18%. is preferable from the viewpoint of effective use of inexpensive raw materials and avoidance of styrene dimerization.

In the present invention, obtained in this way,
An alkylation product of styrene with xylene and/or toluene, or with at least one of these compounds and ethylbenzene, with a boiling point
A fluid having a temperature of less than 270 to 340°C, preferably 280 to 320°C is hydrogenated and used as a traction drive fluid. In this case, the product of alkylation of toluene has a boiling point of 291-293 °C, 143-144 °C (11 mm
Hg), 154-155.8℃ (14mmHg), specific gravity (17/4
The main component is α-phenyl-α-tolylethane, which has a refractive index (n 17 _D ) of 1.566 and a refractive index (n ¹⁷ D ) of 1.566. In addition, the product of alkylating xylene has a boiling point of 311~
317℃, 240-243 (110mmHg), specific gravity (15/4℃)
The main component is α-phenyl-α-(dimethylphenyl)ethane with a molecular weight of 0.987.

Hydrogenation includes nickel, nickel oxide, nickel-diatomaceous earth, Raney-nickel, nickel-copper, platinum, platinum oxide, platinum-activated carbon, platinum-rhodium,
Platinum-Alumina, Platinum-Lithium-Alumina, Rhodium-Activated Carbon, Palladium, Cobalt, Raney
This is achieved by contacting a mixture of an alkylated product and hydrogen with a well-known aromatic hydrogenation catalyst represented by cobalt, palladium, ruthenium, tungsten sulfide-nickel sulfide-alumina at 250°C or lower. This hydrogenation reaction can be carried out either batchwise or continuously, but
In any case, it is desirable to provide a contact time long enough for most of the aromatic nuclei to disappear. That is, if unreacted aromatic compounds remain due to insufficient contact time, they will be included in the hydrogenated product,
This results in a significant reduction in the rolling friction coefficient. From this point of view, the aromatic residual rate, that is, [(residual phenyl group mol/l)/(alkylated product
It is preferable to provide sufficient contact time so that mol/l)×2]×100 is 2% or less, particularly preferably 0.5% or less. Generally, in the hydrogenation reaction of organic compounds, the required contact time is shortened by increasing the hydrogen pressure (reaction pressure) or the reaction temperature. Of course, such an attempt is effective in the present invention, but adopting a harsh reaction temperature in order to complete the hydrogenation reaction may lead to dealkylation (decomposition) of the alkylated product and the formation of tar as a by-product. This leads to reduced yields of the traction drive fluid and premature deterioration of the hydrogenation catalyst. Therefore, care should be taken not to exceed the above-mentioned 250°C as the hydrogenation reaction temperature of the alkylated product. Reaction conditions that can be used in the hydrogenation reaction of the present invention include, for example, Raney-nickel catalyst (130-240°C, 30-200 atm), Raney-cobalt catalyst (130-180°C, 20-200 atm), nickel oxide catalyst (130-180°C, 20-200 atm), Catalyst (150-250℃, 20-100 atm), Nickel-diatomaceous earth catalyst (120-200℃, 10-180 atm), Platinum black catalyst (100-250℃, 80-100 atm), Platinum-activated carbon catalyst (150 ~180℃, 20-80 atm), platinum-alumina catalyst (200-250, 27-100 atm), rhodium-activated carbon (80-200℃, 30 atm) for 30 minutes to 15 hours. Contact time can be given. In particular, when a method of contacting for a relatively long time at a temperature of 180°C or lower is adopted, there is almost no decomposition or polymerization of the alkylated product, and therefore the hydrogenated product can be directly used as the traction drive fluid. However, from an economic point of view,
Furthermore, it is desirable to increase the reaction temperature slightly to make the contact time about 30 minutes to 1 hour. In this way, if hydrogenation is to proceed rapidly,
Since decomposition and polymerization of alkylated products are involved, although in small amounts, a fractional distillation step is provided following the hydrogenation step to remove xylene (or toluene) as a decomposition product and tar as a polymer, and
Preferably, the 300°C fraction is used as a traction drive fluid. In this case, as long as the above-mentioned precautions for hydrogenation are taken into account and the hydrogenation is carried out at 250°C or lower, the loss due to decomposition and polymerization of the alkylated product can be suppressed to 3 to 4%.
Therefore, the reduction in lubricating oil yield due to separation of these side reaction products is 4% or less.

The hydrogenated toluene alkylated product obtained by the present invention has a boiling point of 271 to 273°C and 151°C (24 mm
Hg), 140℃ (14mmHg), specific gravity (15/4℃) 0.88,
α having a refractive index ( ^n20D ₎ of 1.480, a pour point of -50°C or lower, and a viscosity (poise) of 0.5 (0°C) and 2.0 (-25°C).
-Cyclohexyl-α-methylcyclohexylethane is the main component. In addition, the hydrogenated product of xylene alkylate has a boiling point of 290 to 295°C, a specific gravity (15/4°C) of 0.89, a refractive index (n ²⁰ _D ) of 1.484, a pour point of -49°C, a viscosity (poise) of 0.5 (0°C), 3.0 (−25
The main component is α-cyclohexyl-α-dimethylcyclohexylethane, which has a

Regarding the values of the traction coefficient (rolling friction coefficient) of the alkylation products of xylene and/or toluene and their hydrogenation products according to the invention, the alkylation products show very unsatisfactory results, whereas the hydrogenation products of The product showed excellent results.

For measuring the rolling friction coefficient, see Lubrication No. 16.
Vol. 8 No. 573 (1971) introduces its principle and measuring device, and the present invention follows this method. Specifically, in a 4-cylinder type friction tester, the rotating shaft of the central cylinder (inner cylinder, 4 cm in diameter) is uncenteredly supported, and for the three cylinders (outer cylinder, 4 cm in diameter) that are in contact with this cylinder, In a device that rotates the inner cylinder in the opposite direction to the outer cylinder by applying rotation in the same direction at the same speed (1500 rpm), a load of 207 kg is applied to the contact surface and a brake is applied to the driven shaft of the inner cylinder. By applying torque, the rotational speeds of the inner and outer cylinders are made to differ (giving a rotational speed difference rate, ie, a slip rate), and the torsional moment of the driven shaft of the inner cylinder is directly measured with a resistance wire strain gauge installed on the shaft. The test pieces (inner and outer cylinders) of this device are made of carbon steel (JIS S45C).
Also, the maximum Hertz load based on the load on the outer cylinder is 93
Kg/ ^mm2 . In measuring the rolling friction coefficient of the traction drive fluid of the present invention,
The temperature of the fluid supplied to the test piece was 25°C unless otherwise noted.

The rolling friction coefficient measured under these conditions is based on the alkylation product of toluene or xylene.
0.047-0.051, hydrogenation product of toluene or xylene alkylation product 0.088-0.092, and various hydrocarbons synthesized for comparison: styrene dimer hydride 0.062, dicyclohexyl 0.060, dicyclohexylmethane
0.062, α,β-dicyclohexylethane 0.063,
α-methylstyrene linear dimer hydride 0.085,
Polyisobutylene hydride 0.056, alkylated hydrogenation product of toluene and formalin
0.066, cyclopentyldecalin 0.063, cyclopentyldicyclohexyl 0.061, and dicyclohexylmethylcyclohexane 0.065.The toluene or xylene alkylated hydrogenation product according to the present invention is significantly superior to ordinary hydrocarbons, and has a particularly large rolling friction coefficient. It has become clear that it is superior to α-methylstyrene linear dimer hydride, which is well-established as a hydrocarbon.

When evaluating the performance of a traction drive fluid, the rolling friction coefficient is of particular importance, but, of course, as with normal lubricants, oxidation stability, pour point, and thermal stability are also important. , viscosity, viscosity index, flash point, corrosiveness to metals, shear stability, abrasion resistance, etc. are also taken into consideration.
Although the traction drive fluid according to the present invention has sufficient performance regarding these items,
Known additives for traction drive fluids, such as tricresyl phosphate, 2,6-
It is also possible to add di-tert-butyl-p-cresol, polyalkyl methacrylate, alkylene glycol pentaborate salt, thiophosphate, phosphoric acid diester, etc., if necessary.

The present invention will be explained in more detail below with reference to Examples and Comparative Examples.

Example 1 (Xylene alkylation method) Mixed xylene (o-32.8%, m-37.6%, p-
19.6%, ethylbenzene 10%) 2 and 85% sulfuric acid
Collect 600g into a stainless steel reactor (5),
Add a mixture of 250 c.c. of styrene and 500 c.c. of mixed xylene to this while cooling with ice from the outside and stirring continuously.
It took a few minutes to add. During this time, the reaction temperature was increased to 10±5
It was kept at ℃. Next, after continuing stirring for 1 hour, it was left to stand and the lower layer (sulfuric acid layer) of the contents of the reactor was separated.
Add 3% sodium hydroxide aqueous solution 1 to the upper layer (oil layer)
was added and stirred for 25 minutes. After that, let it stand again to separate the lower layer (alkaline layer) and the oil layer (upper layer).
After adding 1.5 liters of water, the mixture was stirred for 15 minutes. After this water washing operation was added four times, the oil layer was distilled using a distillation column with 10 theoretical plates and the bottom temperature was raised to 315 to 330°C. After separating unreacted xylene and ethylbenzene as a pre-distillate, 400 c. The alkylated product of c. (distillation temperature 300-319°C) was collected. Also, this fraction is α-
The main component is phenyl-α-[dimethylphenyl]ethane, and the yield relative to styrene is approximately 87%.
It was %. The properties of this fraction are as follows: specific gravity (15/4
°C) 0.987, pour point -48 °C or less, bromine number 0.1, and neither linear dimer nor cyclic dimer of styrene was detected.

400 c.c. of the above alkylated product was collected in an autoclave (1), and after adding 35 g of Raney-nickel, hydrogen was pressurized into it to a maximum of 35 Kg/cm ² , and then,
While continuing to stir, the reaction pressure was increased to 34 to 40 kg/
The temperature is maintained at 60° C. for 2 hours while adding hydrogen to maintain the temperature at cm ² , then the temperature is increased to 180° C. over 3 hours, and further heated at 180 to 200° C. for 4 hours. After that, while still maintaining the reaction pressure at 35-40Kg/ ^cm2 ,
After cooling to room temperature, hydrogen was released and the contents were filtered to remove the catalyst. liquid
From NMR analysis, 99.9% of the alkylated product
I learned that the above was hydrogenated. Distill the liquid to remove a trace amount (1.8g) of decomposition products (xylene,
Excluding ethylbenzene), 288-298℃ distillation 440c.c.
was collected as a traction drive fluid.
This fraction has a specific gravity (15/4℃) of 0.89 and a refractive index (n
^20D ₎ 1.484, pour point -50℃, viscosity 0.5poise (0
℃), kinematic viscosity 2.2cSt (98.9℃), flash point 140℃, viscosity index 5, rolling friction coefficient 0.092 (25℃),
It was 0.071 (80℃). Antioxidant di-tert-butyl is added to this traction drive fluid 120c.c.
As a result of adding 1% p-cresol and heating and oxidizing it under the conditions of air flow rate 5/hr, 350 × 72 hr in accordance with Federal 5308, the total acid value only increased from the initial 0.01 to 0.21. The rate of increase in viscosity (100〓) was 4%, and the weight changes of metal samples such as iron, copper, aluminum, and magnesium subjected to the oxidation catalyst were +0.01, -0.03, -0.01, and 0.00mg/ ^cm2 , respectively.
Furthermore, no coke or sludge was observed, indicating that it has excellent stability even under such severe forced oxidation conditions. Furthermore, when this fluid was used in a Kopp continuously variable transmission, it was found that it was very suitable for use because of its large rolling friction coefficient, and that it caused very little fatigue due to rolling of rotating members.

Example 2 (Method via alkylation of toluene) 2500 c.c. of toluene and 500 g of 82% sulfuric acid were collected in a stainless steel reactor (5), and 250 c.c. of styrene was added over a period of 30 minutes. Reaction temperature 15±5℃
After the addition of styrene is completed, an additional 40
The mixture was stirred for a minute and then allowed to stand for 30 minutes. After separating the lower layer (sulfuric acid) of the reactor, 3% aqueous sodium hydroxide solution 1 was added to the upper layer (oil layer) and stirred for 30 minutes.
After that, the lower layer (alkaline aqueous solution layer) obtained by standing still is separated, and 1.5 parts of water is added to the oil layer, and the mixture is stirred for 10 minutes. For the oil layer after this water washing operation was added four times, a distillation column with 10 theoretical plates was used to lower the column temperature.
After distillation at a temperature of 300-315°C and separating unreacted toluene as a pre-distillate, 353 c.c. of alkylated product (distillation temperature 288-298°C) was collected. This fraction is α
-Phenyl-α-tolylethane was the main component, and the yield based on styrene was 82%. Further, this fraction had a specific gravity (15/4° C.) of 0.985, a refractive index (n ¹⁷ _D ) of 1.566, and a bromine number of 0.1, and neither a linear dimer nor a cyclic dimer of styrene was detected.

350 c.c. of the above alkylated product was collected into an autoclave (1), and after adding 22 g of Raney-nickel, hydrogen was injected into it to a maximum of 33 kg/cm ² , and then,
While continuing stirring, increase the reaction pressure to 30-40Kg/cm ²
The temperature was maintained at 65℃ for 2 hours while adding hydrogen to maintain the temperature, and then the temperature was increased to 160℃ over 3 hours.
After further heating at 160 to 180° C. for 4 hours, the reaction pressure was maintained at 30 to 40 Kg/cm ² and cooled to room temperature, hydrogen was released, and the contents were filtered to remove the catalyst. From NMR analysis of the liquid,
It was found that more than 99.8% of the alkylated product was hydrogenated. Distill the liquid to a trace amount (1.6
Decomposition products of g) (toluene, ethylbenzene)
405 c.c. of the 269-277°C fraction was collected. This fraction has a specific gravity (15/4°C) of 0.88 and a refractive index (n ²⁰ _D )
1.480, pour point -50℃ or less, viscosity 0.5poise (0
It had a kinematic viscosity of 2 cSt (98.9°C), a flash point of 137°C, a viscosity index of 6, and a rolling friction coefficient of 0.090 (25°C). This fluid was used in an actual machine in the same manner as in Example 1, and the results were almost as good as in Example 1.

Comparative Example 1 (method via dimerization of styrene) 1000 c.c. of styrene containing 0.2% t-butylcatechol as a stabilizer, 100 c.c. of concentrated sulfuric acid, and 150 c.c. of water.
Both the sulfuric acid aqueous solution mixed with cc are kept at 120-125°C for 4 hours while stirring and mixing. Next, it was cooled to 50°C, left to stand for 1 hour, and the resulting oil layer was separated.
After diluting by adding 250 c.c. of benzene, it is washed with water using an aqueous solution in which common salt and sodium carbonate are dissolved. Next, by distilling this oil layer, a fraction containing linear styrene dimers (boiling point 146-153℃/
3 mmHg) was obtained in 76% yield (700 g). By redistilling this fraction in a distillation column with 30 theoretical plates, a linear dimer of styrene (boiling point 213.5
°C/50mmHg, refractive index (n ²⁰ _D ) 1.5927 (n ²³ _D )
1.5912, specific gravity (20/4℃) 0.998 (25/4℃)
0.993) 691g was isolated. As a result of gas clost analysis of this fraction, it was confirmed that it did not contain styrene trimer and that styrene cyclic dimer was only 0.5% or less (this was referred to as styrene linear dimer A). do).

Styrene containing 0.2% t-butylcatechol
Add 880g to 85.8% phosphoric acid 1 and stir;
After heating at 120°C for 48 minutes, the mixture was cooled to 50°C, left to stand for 5 minutes, and then the oil layer was separated. Also, benzene is added to the acid layer.
The operation of adding 200 c.c. and extracting the oil contained in the acid layer was repeated five times, and the resulting benzene solution was combined with the oil layer. This was washed with water to remove adhering phosphoric acid, then 10 g of t-butyl catechol was added, and benzene was distilled off under conditions of 70°C and 3 mmHg, followed by distillation to separate a 150-200°C/20 mmHg fraction. . The distillation residue was styrene trimer, and the distillate was styrene dimer consisting of 61% linear dimer and 39% cyclic dimer. These yields were 18% trimer, 79% dimer, and a total of 97%.
The yield of the tetramer was 3% or less (the dimer obtained here (61% linear, 39% cyclic) was referred to as styrene dimer B).

Styrene containing 0.2% t-butyl catechol
47% sulfuric acid 1 was added to 880 g, stirred at 120°C for 2 hours, cooled to 50°C, left to stand for 5 minutes, and then the oil layer was separated. The operation of adding 300 c.c. of benzene to the sulfuric acid layer for extraction was repeated five times, and the resulting benzene solution was combined with the oil layer. After washing this with water, 10g
Add t-butyl catechol and heat at 150-200℃/
A 20 mmHg fraction was separated. Styrene trimer (yield: 15%) was obtained as the distillation residue, and linear dimer (content: 91%) and cyclic dimer (content: 9%) accounted for a total of 81% of the above fraction. (This is referred to as styrene dimer C).

500 g each of the styrene linear dimer A, dimer B, and C obtained here were placed in an autoclave (1
), reaction pressure 100Kg/cm ² , reaction temperature 215
℃, 8 under the condition of using nickel-diatomaceous earth catalyst amount of 50g
The catalyst was separated by hydrogenation for an hour and filtering the contents. 145 obtained by distilling this
The ~148°C/8.5mmHg fraction was found to be free of aromatic nuclei by infrared spectroscopy. The results of measuring the rolling friction coefficients for each were 0.063 for the hydrogenated styrene linear dimer A, 0.059 for the hydrogenated styrene dimer B, and 0.061 for the hydrogenated styrene dimer B. ) or the hydrogenation product of the alkylated product of toluene (Example 2) (0.092-0.090).

Comparative Example 2 (Method via alkylation of toluene and cyclohexene) 10 g of aluminum chloride was added to 920 g of toluene, 6 ml of hydrogen chloride gas was blown into the mixture, and then 1640 g of cyclohexene was added and stirred for 4 hours. Next, the operation of adding 1 part of water and washing was repeated 8 times, and after distilling off a total of 250 g of unreacted toluene and cyclohexene, 208 to 214
The °C/20 mmHg fraction was collected. This fraction (boiling point 340
As a result of measuring the molecular weight (~355°C) and further examining it using an infrared absorption spectrum, it was determined that it was dicyclohexyltoluene. The yield was 90% (2340 g) based on cyclohexene. Also,
Its pour point is -10℃ or less, flash point 192 _℃ , refractive index ( ^n20D ) 1.5360, specific gravity (20/4℃) 0.959, viscosity
They were 96.3cSt (37.8℃) and 5.56cSt (98.9℃).
Collect 500g of this in an autoclave, reaction pressure 100
Hydrogenation treatment was carried out for 10 hours under the conditions of Kg/cm ² , reaction temperature of 215° C., and nickel diatomaceous earth catalyst usage amount of 50 g, and the catalyst was separated by filtering the contents. The 160-164℃/4mmHg fraction obtained by distilling this was found to contain no aromatic components and was found to contain dicyclohexylmethylcyclohexane (boiling point 320-330℃, 140℃/20mmHg, 163℃/
4 mmHg), but its rolling friction coefficient was 0.069, and in the case of the method via alkylation of toluene and styrene according to the present invention (Example 2;
0.090), it was extremely unsatisfactory. That is, styrene is suitable as an alkylating agent for toluene, and cyclohexene is inappropriate.

Comparative Example 3 (Hydrogenation method of diphenylmethane) 2180 g (2060 c.c.) of benzyl alcohol and 1560 g (1780 c.c.) of benzene were placed in 10 flasks, 940 g of boron trifluoride gas was blown into the flask, and then placed in an autoclave. The mixture was transferred and stirred and heated at 60°C for 9 hours. After cooling, separate the lower layer (acid layer) of the contents and transfer to the upper layer (oil layer) with 1.5% aqueous sodium hydroxide solution.
After repeating the operation of adding, stirring and washing eight times, a 173-176°C fraction/72 mmHg (480 g) was collected by distillation. This fraction has a boiling point of 261℃, 175℃/72mm,
149℃/29mm, 85℃/1mmHg, specific gravity (30/4℃)
0.997, viscosity 0.01564 g/cm, sec (59°C), refractive index ( ^n25D ) 1.570, and was found to be diphenylmethane by NMR _spectrum and gas cross analysis. The yield was about 460 g, a yield of about 15%, and 989 g of high-boiling substances such as dibenzylbenzene and tribenzylbenzene were produced as by-products.

460 g of the obtained diphenylmethane, 1.5 ethanol and 60 g of reduced nickel catalyst were placed in an autoclave, and after hydrogen treatment at 150°C and 175 kg/ ^cm2 for 7 hours, 440 g of a 249-253°C fraction was obtained by distillation. . This fraction has a boiling point of 150℃/45mm
Hg, 131℃/19mmHg, 87℃/0.4mmHg, specific gravity (20/4℃) 0.876, (80/4℃) 0.834, refractive index (n ²⁰ _D ) 1.4755, (n ⁸⁰ _D ) 1.4505, and dicyclohexylmethane. It turned out to be. The rolling friction coefficient of this fraction was measured and the result was 0.062.
This was an unsatisfactory value compared to the method of hydrogenating an alkylated product of toluene or xylene with styrene according to the present invention (Examples 1 and 2; 0.090 to 0.092).

Comparative Example 4 Isobutylene 6-7mer obtained by thermally decomposing isobutylene polymer using aluminum chloride catalyst
500g and 50g of palladium catalyst supported on activated carbon
Collected in an autoclave, 275℃, 100Kg/cm ²
Hydrogenated polyisobutylene having a viscosity index of 105 and a pour point of -51°C or lower was obtained by hydrogenation treatment for 8 hours under the following conditions, but its rolling friction coefficient was only 0.056.

Comparative example 5 480g of α-methylstyrene and 97g of titanium tetrachloride
After stirring at room temperature for 24 hours, add benzene.
After diluting with 600c.c. and washing three times with 1N-hydrochloric acid 200c.c., repeating the neutralization washing operation three times with 1N-sodium hydroxide 200c.c., then 300c.c. The washing operation with water in c. was repeated 7 times. Thereafter, the oil layer was subjected to fractional distillation, and 304 g of a 115-178°C/0.1 mmHg fraction was collected. NMR spectroscopy and gas clost analysis revealed that the main components were α-methylstyrene cyclic dimer and cyclic trimer.
By further fractionating this fraction, 115 to 120
C/0.1 mmHg (cyclic dimer) fraction 233 g was obtained.
In addition, from the above polymerization product, in addition to the cyclic dimer to trimer, 208 to 212 ° C / 0.1 mmHg fraction (tetramer),
48g, 240-244℃/0.1mmHg fraction (pentamer), 43
g, 275-285℃/0.1mmHg fraction (hexamer), 41
g, 312-316℃/0.1mmHg fraction (heptamer), 38
g, 345-360℃/0.1mmHg fraction (octamer), 5g
was also obtained, and the yield of the dimer fraction was only slightly less than 50%. The above dimer fraction (boiling point 118-120℃/0.1mm
Hg, specific gravity (20/4℃) 0.99, refractive index (n ²⁰ _D )
1.563) 230g was collected into an autoclave along with 4g of Raney-nickel catalyst, and after pressurizing hydrogen to 210Kg/cm, heating it to 150-220℃, additional hydrogen was injected, and the reaction pressure was 210Kg/ ^cm2 . Time was maintained. Thereafter, it was cooled to room temperature, the contents were filtered, and the resulting liquid was distilled to remove 3 g of a fraction below 125°C, and then a 110-114°C/2 mmHg fraction was collected. This fraction has a specific gravity (20/4℃) of 0.890 and a boiling point of 200.
°C/32mmHg, refractive index ( ^n20D ₎ 1.4875, viscosity (20
℃) 0.208 g/cm, sec, and is considered to be a cyclic dimer hydrogenation product. The rolling friction coefficient of this fraction is 0.080, and in the case of the toluene or xylene alkylation method of the present invention (0.090 to 0.092).
I found out that it is considerably inferior to .

Comparative Example 6 35 g of acid clay, 35 g of ethylene glycol and 610 g of α-methylstyrene were placed in a flask, and 150 g of
The mixture was stirred at reflux for 1 hour at °C. By filtering the contents and analyzing the liquid, α-methylstyrene (unreacted portion), 60 g of ethylene glycol, α-
I learned that it contained about 520 g of methylstyrene linear dimer and about 50 g of other high polymers. Than this,
α-Methylstyrene and ethylene glycol were distilled off, and then 520 g of a 171-175°C/10 mmHg fraction was obtained. This fraction has a boiling point of 117-120℃/0.1mmHg, a specific gravity (20/4℃) of 0.989, and a refractive index ( ^n20D ) of 1.5675. Gas chromad analysis reveals _that 94% of linear dimers and cyclic dimers are present. It was found that it consisted of 6%. The distillation residue (50 g) was a trimer to tetramer of α-methylstyrene. Next, 500 g of the above 171-175° C./10 mmHg fraction was placed in an autoclave together with 48 g of Raney-nickel catalyst, and hydrogen was pressurized to 35 kg/cm ² . The reaction pressure was maintained by supplying additional hydrogen at 60°C for 2 hours, then
Hydrogenation treatment was carried out at 180°C for 3 hours and then at 200°C for 1 hour, and after cooling, the contents were filtered to remove the catalyst. The liquid was found to have an unsaturated content of 0.1% or less by NMR spectrum, but by distilling it, the refractive index (n ²⁰ _D ) was 1.4877 and the specific gravity (20/4
℃) 0.90, boiling point 194-197℃/16mmHg, kinematic viscosity (cSt) 3500 (-18℃), 3.7 (98.9℃), 22.7 (37.8
℃), viscosity index 5, flash point 14.9℃, pour point -44℃
A linear dimeric hydride fraction of . It was found that the rolling friction coefficient of this fraction was 0.085, which is inferior to that of the present invention using the toluene (or xylene alkylation method) (0.090 to 0.092).
In addition, according to this comparative example, in the dimerization of α-methylstyrene, by-products mainly consisting of trimers and tetramers were produced.
It is also clear that about 20% was obtained, and the yield (selective production rate) of the desired linear dimer was only about 80%.

Claims (1)

[Scope of Claims] 1. A traction drive fluid obtained by hydrogenating a fraction having a boiling point of 270 to less than 340°C using an alkylation reaction product of xylene and/or toluene and styrene. 2. An alkylation reaction product of styrene and xylene and/or toluene and a mixture containing less than 50% by weight of ethylbenzene based on at least one of these compounds, obtained by hydrogenating a fraction with a boiling point of 270 to less than 340°C. Traction drive fluid.