JPH05247481A - Traction drive fluid - Google Patents

Abstract

PURPOSE:To obtain the title fluid having a high coefficient of traction, excellent viscosity-temperature characteristics, excellent low-temperature pour and good compatibility with a sealing material, being capable of the reduction in the size and weight of a device, and suited for especially an automobile infinitely variable transmission. CONSTITUTION:The title fluid comprises 1-50wt.% dimethyl-silicone having a kinematic viscosity of 5-30cSt at 40 deg.C and 50-99wt.% product of hydrogenation of a polymer which is a cyclopentadiene-based condensed ring hydrocarbon comprising at least one polymer obtained by thermally polymerizing or copolymerizing a cyclopentadiene or both a cyclopentadiene and an alpha-olefin and/or a monovinylaromatic hydrocarbon, and consisting mainly of tri- to hexamers of cyclopentadiene and having a kinematic viscosity of 5-40cSt at 40 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel traction drive fluid. More specifically, the present invention has a high traction coefficient suitable for a traction drive such as an automobile transmission having a large torque capacity and severe operating conditions, and has a viscosity-temperature characteristic, low temperature fluidity, seal material compatibility, etc. The present invention relates to a traction drive fluid with excellent performance.

[0002]

2. Description of the Related Art A traction drive device is a power transmission system utilizing rolling-sliding friction caused by a resistance force against shearing caused by a fluid oil film sandwiched by a cylindrical or conical rotating body losing its fluidity under high pressure and hardening. It is a device. This traction drive device has been researched for high performance or small size and light weight, especially for automobile applications in recent years, and a fluid for traction drive is required to have high performance and excellent economical efficiency.

As a fluid for a traction drive, it has been proposed to use a special synthetic base oil having a high traction coefficient, which is a measure of power transmission capacity, and is disclosed in JP-A-62-177098.
No. 3, JP-A-63-230794, JP-B-53-361
Various proposals have been made in No. 05 and the like. In recent years, in particular, a traction drive fluid that can provide a stable traction coefficient over a wide temperature range has been disclosed in JP-A-1-156397.
JP-A-1-198693, JP-A-2-88697
Has been proposed, and many studies for automobile applications are being carried out.

[0004]

However, even if these are excellent in traction characteristics, they do not satisfy other practical performances, and particularly when used for automobiles, viscosity-temperature characteristics, low temperature fluidity However, there were many practically inconvenient points, such as poor low-temperature start-up property and evaporation property, insufficient sealing material compatibility, and insufficient flash point. These defects are
It is derived from the base oil composition and is attributed to the use of a special synthetic base oil for the traction drive fluid. As a countermeasure against this, improvement of performance by additives, for example, viscosity-temperature characteristics may be improved by adding a polymer such as a viscosity index improver.However, shearing of polymer molecules causes a decrease in effective viscosity, and a rotating body due to oil film breakage, etc. There is a fear that the damage will occur and it cannot be a fundamental solution to the problem. On the other hand, silicone oil is mentioned as a synthetic oil having excellent viscosity-temperature characteristics, low temperature fluidity, and vaporization property. However, not only is silicone oil extremely expensive, but also compatibility with other lubricants and additives. It was extremely low and poor in practicality.

The present invention overcomes the disadvantages of the conventional traction drive fluids and has excellent traction characteristics as well as excellent performance derived from the base oil such as viscosity-temperature characteristics and seal material compatibility. The purpose is to provide a fluid for a traction drive.

[0006]

Means for Solving the Problems The inventors of the present invention have made earnest studies to develop a fluid for a traction drive having the above-mentioned excellent performance. As a result, dimethyl silicone having a kinematic viscosity of 5 to 30 cSt at 40 ° C. Cyclopentadiene type 3 obtained by thermal polymerization or thermal copolymerization having a kinematic viscosity of 5 to 40 cSt at 40 ° C. in an amount of 1 to 50% by weight.
A traction drive fluid containing 50 to 99% by weight of a hydride of a condensed ring hydrocarbon having at least one of hexamers and having specific structural characteristics as an essential component is excellent. It was discovered that these materials have excellent performance, and completed the present invention.

That is, the gist of the present invention is (A) 40 ° C.
1-50% by weight of dimethyl silicone having a kinematic viscosity of 5 to 30 cSt, and (B) cyclopentadiene or cyclopentadiene and α-olefin and / or monovinylaromatic having a kinematic viscosity of 5 to 40 cSt at 40 ° C. A cyclopentadiene-based condensed ring hydrocarbon composed of at least one multimer obtained by thermal polymerization or thermal copolymerization with hydrocarbons, which comprises a cyclopentadiene-based trihexameric hexamer as a main component and a norbornene ring. The ratio of the amount of hydrogen on the double bond to the amount of hydrogen on the cyclopentene ring double bond (ND / CD) is 0.9 to 1.3. It exists in the fluid for traction drive, which is characterized by

Next, the present invention will be described in detail. The traction drive fluid of the present invention comprises a specific dimethyl silicone as the component A and cyclopentadiene-based 3 to 3 obtained by thermal polymerization or thermal copolymerization as the component B. Two components of a specific condensed ring hydrocarbon hydride consisting of at least one kind of hexamer are blended as essential components in a specific ratio.

The dimethyl silicone which is the component A of the present invention has a polydimethylsiloxane structure whose main chain is a silicon-oxygen bond. These dimethyl silicones may have a kinematic viscosity at 40 ° C. of 5 to 30 cSt, and those having a kinematic viscosity of 10 to 25 cSt are particularly preferably used. 40 ° C
If the kinematic viscosity is less than 5 cSt, the oil film holding capacity will be reduced and the evaporation will be increased.
When it is larger than the above range, the solubility of the condensed ring hydrocarbon which is the B component in the hydride is lowered to cause clouding and separation, which is not preferable. Further, dimethyl silicone is blended in an amount of 1 to 50% by weight, preferably 5 to 30% by weight. If the compounding amount is less than 1% by weight, the effect of the compounding is so small that the improvement of the viscosity characteristic and the compatibility of the sealing material cannot be recognized. Also, the compounding amount is 50% by weight.
If the amount is larger, not only the traction characteristics deteriorate but also the cost is not preferable. There are no particular restrictions on the raw material and manufacturing method of the dimethyl silicone that is the component A, and various commercially available products can be appropriately used. Of course, it can also be produced by polymerizing dimethylsiloxane by a known method.

On the other hand, the hydrogenated cyclopentadiene-type condensed ring hydrocarbon which is the component B of the present invention is a cyclopentadiene or cyclopentadiene and an α-olefin and / or a monovinylaromatic hydrocarbon which are thermally polymerized or co-polymerized. After polymerization, cyclopentadiene-based 3 to 3
It can be obtained by separating and recovering a condensed ring hydrocarbon containing a hexamer as a main component by distillation or the like, and further hydrogenating it by a usual method.

The cyclopentadiene used in the present invention includes cyclopentadiene, a multimer thereof, an alkyl-substituted product thereof, or a mixture thereof.
Industrially, it is advantageous to use a cyclopentadiene-based fraction (CPD fraction) containing about 30% by weight or more, preferably about 50% by weight or more of cyclopentadiene obtained by steam cracking of naphtha or the like.

Further, the CPD fraction may contain an olefinic monomer copolymerizable with these alicyclic dienes. Examples of the olefinic monomer include aliphatic diolefins such as isoprene, piperylene and butadiene, and alicyclic olefins such as cyclopentene. The concentration of these olefins is preferably low, but about 10% by weight or less per cyclopentadiene is acceptable.

The α-olefins as a raw material for copolymerization with cyclopentadiene are C _{4 to} C ₁₄ , preferably C ₄
Α- olefin and mixtures thereof -C ₁₀ and the like, ethylene, degradation products of derivatives or paraffin wax from propylene or 1-butene are preferably used. It is industrially preferable that the amount of the α-olefin is less than 4 mol per mol of the cyclopentadiene.

Other monovinylaromatic hydrocarbons as copolymerization raw materials include styrene, o, m, p-vinyltoluene, α, β-methylstyrene, etc., and less than 3 mol per 1 mol of cyclopentadiene. It is industrially preferable to blend it. The monovinyl aromatic hydrocarbons may contain indenes such as indene, methylindene or ethylindene, and industrially it is advantageous to use a so-called C ₉ fraction obtained by steam cracking such as naphtha. is there.

The amount is calculated as 1 mol when a monomer such as cyclopentadiene is used as the cyclopentadiene and as 2 mol when a dimer is used.

The following method can be mentioned as one of the thermal polymerization or thermal copolymerization methods for obtaining a cyclopentadiene type condensed ring hydrocarbon. For example, these cyclopentadiene or cyclopentadiene and α-olefin or monovinyl aromatic hydrocarbon are preferably present in the presence or absence of a solvent, preferably in an inert gas atmosphere such as nitrogen gas at about 160 to 300 ° C. Thermal polymerization or thermal copolymerization is preferably carried out in a temperature range of about 180 to 280 ° C. for about 0.1 to 10 hours, preferably about 0.5 to 6 hours under a pressure capable of maintaining the raw material system in the liquid phase.

After removing the inactive components in the raw materials, the unreacted raw materials and, if necessary, the solvent from the polymerization liquid under reduced pressure to increased pressure by an operation such as distillation, the second-stage polymerization is continued under reduced pressure at about 160 to 280. It is possible to obtain a desired multimer having a cyclopentadiene-based trimer and a hexamer as a main component, while carrying out at 0.5 ° C. for about 0.5 to 4 hours.

The ratio (ND) of the amount of hydrogen on the norbornene ring double bond (ND) to the amount of hydrogen on the cyclopentene ring double bond (ND / CD) of the cyclopentadiene type 3 to 6 mer is determined by the hydrogen nuclear magnetic resonance method. It was determined by the ratio of the amount of hydrogen on the norbornene ring double bond near 5.9 ppm and the amount of hydrogen on the cyclopentene ring double bond near 5.6 ppm measured by ( ¹ H-NMR). The conditions of the above-mentioned thermal polymerization or thermal copolymerization are set so that the ND / CD of the cyclopentadiene-based multimer is 0.9 to 1.3, preferably 0.9 to 1.0. If ND / CD is smaller than 0.9 or larger than 1.3, the traction coefficient becomes low, which is not preferable. That is, the cyclopentadiene-based condensed ring hydrocarbon of the present invention is mainly composed of a cyclopentadiene-based trimer or hexamer having the ND / CD ratio as described above.

Further, the condensed ring hydrocarbon containing the cyclopentadiene-based trimer and hexamer according to the present invention as the main component exhibits excellent characteristics even if it is not hydrotreated, but it has odor and oxidative stability during handling. Further, the hydrotreatment is performed in consideration of other performances.

The hydrotreatment can be carried out by a usual method. For example, a hydrogenation catalyst such as nickel, palladium or platinum is used, and the amount thereof is about 70 in the presence or absence of a solvent.
-300 ° C., preferably about 100-250 ° C., hydrogenation pressure of about 10-200 kg / cm ² (G), preferably about 20-120 kg / cm ² (G) under pressure of about 0.5-.
The hydrotreatment may be performed for 20 hours, preferably for about 1 to 10 hours. After the hydrogenation treatment, the catalyst and, if necessary, the solvent are removed to obtain the desired hydrogenated cyclopentadiene type condensed ring hydrocarbon which is the B component of the present invention.

The hydrogenated cyclopentadiene type condensed ring hydrocarbon which is the B component of the present invention does not necessarily need to contain all of the multimers of each degree of polymerization from the trimer to the hexamer as the main component. The kinematic viscosity of hydride at 40 ° C is 5
It is selected to be in the range of 40 cSt, preferably 10-30 cSt. If the kinematic viscosity at 40 ° C is less than 5 cSt, the flash point, the compatibility with sealing materials, the increase in vaporization and the oil film retention capacity are deteriorated, which is not preferable. And decrease in low temperature fluidity due to increase in viscosity are not preferable. The hydrogenated cyclopentadiene-based condensed ring hydrocarbon is 50 to 99% by weight, preferably 70 to 9% by weight.
5% by weight is blended. If the blending amount is less than 50% by weight, the traction characteristics and the compatibility with dimethyl silicone deteriorate, which is not preferable.

The traction drive fluid of the present invention is sufficiently effective only with the above-mentioned components A and B, but other commonly used base oils such as mineral oil and synthetic oil may be added alone or in a mixture. You can also The higher the traction coefficient of these is, the more desirable it is, but the compatibility must be carefully considered.

The traction drive fluid which is the object of the present invention can be prepared by adding about 0.05 to 10% by weight of various additives such as an antioxidant and an antiwear agent, depending on the application.

[0024]

The fluid for traction drive of the present invention has excellent compatibility because it contains a specific dimethyl silicone and a specific hydrogenated cyclopentadiene-based condensed ring hydrocarbon in a specific ratio, and the advantage of each component is that the two are mixed. It is considered that the peculiar effect of the present invention is brought about because it appears in a complementary manner.

That is, dimethylsilicone has excellent characteristics of viscosity-temperature characteristics, low-temperature fluidity, and low evaporation property, but is extremely inferior in solubility to base oils and additives other than silicone oil, and traction The coefficient was not satisfactory either. However, among these, a specific dimethyl silicone as the A component and a specific hydrogenated cyclopentadiene-based condensed ring hydrocarbon as the B component are mixed at a specific ratio to show excellent compatibility, and further,
The excellent practical performance of the dimethyl silicone described above and the excellent traction characteristics due to the three-dimensional structure of the hydrogenated cyclopentadiene-based condensed ring hydrocarbon having a ring structure are not impaired even by mixing, respectively, and the respective advantages are sufficiently expressed. It is considered that the excellent effect of the traction drive fluid of the present invention was obtained.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited by these examples.

The traction drive fluids obtained in Examples and Comparative Examples were evaluated by the following methods.

Compatibility: After the sample was left standing for 1 week and then visually evaluated, the case where a transparent and uniform mixture was obtained was marked with ◯, and the case where the mixture became cloudy or separated was marked with x.

Traction coefficient: Drive shaft speed 1,000 rpm (2.09 m /
s), the slip ratio was 5%, the normal load was 114 kg, and the ratio of the transmitted tangential force to the normal load measured at the test oil temperature of 30 ° C was used.

Sealing material compatibility: In accordance with JIS K 6301, a test was conducted using nitrile rubber at 120 ° C. for 72 hours.

Flash point: In accordance with JIS K 2265, it was evaluated by a Cleveland open type test.

Evaporation loss: 1 by open beaker method
The evaluation was performed under the conditions of 60 ° C. and 24 hours.

The following reference example shows an example of producing a hydrogenated cyclopentadiene-based condensed ring hydrocarbon compounded in the fluid of the present invention.

Reference Example 1 CPD fraction 600 consisting of 75.0% by weight of dicyclopentadiene obtained by steam cracking of naphtha, 5.4% by weight of olefin, and most of the balance of saturated hydrocarbon.
g and 400 g of xylene as a solvent in a nitrogen atmosphere at 18 kg /
cm ² (G) was thermally polymerized at 260 ° C. for 3 hours. After the inert fraction in the raw material, the unreacted raw material and the solvent were distilled off from the polymerization liquid at 160 ° C. under pressure first and then under reduced pressure, 50 Torr. While maintaining at the same temperature for 1 hour under reduced pressure, the second stage polymerization was carried out while recovering 56 g of the target cyclopentadiene-based condensed ring hydrocarbon. 420 g of cyclopentadiene resin having a softening point of 102 ° C. was obtained as a residue from the kettle. ND / C of recovered cyclopentadiene-based condensed ring hydrocarbon
D was 1.0, and then 2% by weight of a nickel catalyst was added to 56 g of the distillate and hydrogenated at a hydrogen pressure of 60 kg / cm ² (G) at a reaction temperature of 180 ° C. for 4 hours to obtain a hydrogenated cyclopentadiene system. About 56 g of condensed ring hydrocarbon B-1 was obtained. This B-1
Contains 41% by weight, 25% by weight, 19% by weight and 7% by weight of cyclopentadiene 3,4,5, hexamer in terms of GPC area ratio, respectively, and the kinematic viscosity at 40 ° C. is 18.3.
It was cSt.

Reference Example 2 600 g of the CPD fraction used in Reference Example 1 (6.8 mol of cyclopentadiene) and 2,4,4-trimethylpentene-
400 g of a C ₈ fraction containing 75% by weight of 1 and other fractions other than α-olefin (2.
(7 mol) was thermally copolymerized in the same manner as in Reference Example 1. The inert fraction in the raw material and the unreacted raw material were distilled off from the thermal copolymerization liquid at 239 ° C. under pressure first and then under reduced pressure, and 50 Torr. The mixture was maintained at the same temperature for 1 hour under reduced pressure to obtain 96 g of a cyclopentadiene-based condensed ring hydrocarbon containing the target cyclopentadiene-α-olefin copolymer and 357 g of a cyclopentadiene resin having a softening point of 142 ° C. The cyclopentadiene-based condensed ring hydrocarbon had an ND / CD of 1.0, and then was hydrogenated under the same conditions as in Reference Example 1 to obtain a hydrogenated cyclopentadiene-based condensed ring hydrocarbon B-2. The proportions of the cyclopentadiene 3,4,5,6 mer of B-2 were determined by GPC area ratio to be 34% by weight, 24% by weight, 18% by weight and 11% by weight, respectively, and at 40 ° C. The kinematic viscosity is 21.
It was 2 cSt.

Examples 1 to 5 and Comparative Examples 1 to 5 As shown in Table 1 and Table 2, traction drive fluids were prepared. The results are also shown in Tables 1 and 2.

The components in the formulations used in Examples and Comparative Examples are as follows.

A-1: Dimethyl silicone viscosity (40 ° C.) 14.
8cSt A-2: Dimethyl silicone viscosity (40 ° C.) 24.
8cSt A-3: Dimethyl silicone viscosity (40 ° C) 37.
8 cSt; this is outside the range specified by the present invention. B-1: Obtained in Reference Example 1 Viscosity (40 ° C.) 18.
3 cSt B-2: obtained in Reference Example 2 viscosity (40 ° C.) 21.
2cSt B-3: Low boiling point fraction of the product obtained in Reference Example 1 Viscosity (40
C.) 10.2 cSt B-4: High boiling point fraction viscosity of the product obtained in Reference Example 1 (40
° C) 52.6 cSt; this is outside the range specified by the present invention.

In Comparative Example 1, the viscosity of B-4 used was outside the range of the present invention, in Comparative Example 2 the viscosity of A-3 used was outside the range of the present invention, and in Comparative Example 3 the components used were used. The blending ratio is outside the range of the present invention, and Comparative Example 4 is an example in which dimethyl silicone is not used.

[0040]

[Table 1]

[0041]

[Table 2]

From the above Examples 1 to 5 and Comparative Examples 1 to 5, the traction drive fluid of the present invention (Examples 1 to 1)
It can be seen that 5) has remarkably excellent overall performance as compared with any of Comparative Examples 1 to 5.

In other words, the results of the examples are well balanced and excellent in each characteristic such as viscosity-temperature characteristic, low temperature fluidity and sealant compatibility while having a high traction coefficient. On the contrary, the commercially available traction drive fluid of Comparative Example 5 has an extremely excellent traction coefficient, but is extremely inferior in viscosity-temperature characteristics and low temperature fluidity,
In addition, the compatibility with the sealing agent cannot be satisfied, and there is an extremely problem in practical performance. Further, the fluid of Comparative Example 3 has an extremely low traction coefficient and is unsuitable as a fluid for a traction drive, and the fluid of Comparative Example 4 has a high traction coefficient similar to the fluid for a commercial traction drive of Comparative Example 5, but other Only the performance is not very satisfactory. The fluids of Comparative Examples 1 and 2 are inferior in compatibility and hard to put into practical use.

[0044]

Since the traction drive fluid of the present invention has excellent traction characteristics, it is possible to maintain a stable power transmission capability at all times and to reduce the size and weight of the device and prolong its service life. The traction drive fluid of the present invention has a high traction coefficient but is also excellent in practical performance such as viscosity-temperature characteristics, low temperature fluidity, seal material compatibility, and evaporation characteristics. It can be suitably used for a device having a large capacity and severe operating conditions.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C10N 40:04

Claims (1)

[Claims] 1. (A) The kinematic viscosity at 40 ° C. is 5 to 30.
1-50 wt% of dimethyl silicone which is cSt, and (B) cyclopentadiene or cyclopentadiene having a kinematic viscosity of 5-40 cSt at 40 ° C. and α-olefins and / or monovinyl aromatic hydrocarbons are heated. A cyclopentadiene-based condensed ring hydrocarbon consisting of at least one or more multimers obtained by polymerization or thermal copolymerization, which comprises a cyclopentadiene-based 3 to 6-mer as a main component and hydrogen on a norbornene ring double bond. Amount and the amount of hydrogen on the cyclopentene ring double bond (ND / CD)
50 to 99% by weight of hydride of polymer having 0.9 to 1.3
A fluid for a traction drive, characterized by containing as an essential component.