JP2929337B2 - Fluid for traction drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel traction drive fluid. More specifically, the present invention has a high traction coefficient in a wide temperature range suitable for traction drives having a large torque capacity such as an automobile transmission and severe use conditions, and has performance such as viscosity characteristics and sealing material compatibility. Traction drive fluids

[0002]

2. Description of the Related Art A traction drive device transmits power using rolling-sliding friction caused by a shear force generated by a fluid oil film sandwiched between a cylindrical or conical rotating body which loses fluidity due to high pressure and hardens. Device. In recent years, traction drive devices have been studied for higher performance or smaller size and lighter especially for automotive applications, and traction drive fluids are required to have high performance and excellent economy.

For a traction drive fluid, use of a special synthetic base oil having a high traction coefficient, which is a measure of power transmission capacity, has been proposed.
77098, JP-A-63-230794, JP-B-5
Various proposals have been made in JP-A-3-36105 and the like. Also, in recent years, a traction drive fluid capable of providing a stable traction coefficient over a wide temperature range has been disclosed in Japanese Patent Application Laid-Open Publication No. Hei.
56397, JP-A-1-198693, JP-A-2-1986
No. 88697, and a number of studies for automotive applications are underway.

[0004]

However, even if they are excellent in traction characteristics, they do not satisfy other practical performances. Particularly, when they are used for automobiles, they have viscosity-temperature characteristics and low temperature fluidity. There were many practical inconveniences, such as poor properties, low-temperature startability, and problems with evaporability, insufficient compatibility with sealing materials, and insufficient flash point. These disadvantages are derived from the base oil composition and are attributed to the use of special synthetic base oils for traction drive fluids. As a countermeasure against this, it is conceivable to improve the performance by additives, for example, to improve the viscosity-temperature characteristics by adding a polymer such as a viscosity index improver. It is feared that it will not be a fundamental solution to the problem.

The present invention overcomes the drawbacks of the conventional traction drive fluid, and in addition to excellent traction characteristics, has excellent traction characteristics derived from base oils such as viscosity characteristics and sealing material compatibility. It is intended to provide a working fluid.

[0006]

The present inventors have made intensive studies to develop a traction drive fluid having the above-mentioned excellent performance, and as a result, cyclopentadiene and α have been determined on the basis of a completed traction drive fluid. -5 to 30% by weight of a cyclopentadiene-based petroleum resin having a softening point of 40 ° C or more or a weight-average molecular weight of 250 or more, which is a thermal copolymer with olefins and / or monovinyl aromatic hydrocarbons or a hydride thereof, Average molecular weight of 100
Branched poly-α-olefins 1 to 1,000
The inventors have found that a traction drive fluid to which 5 to 95% by weight is added as an essential component has excellent performance satisfying its purpose, and have completed the present invention. In addition,
The effect was not recognized in the case of blending a thermopolymerized petroleum resin or a hydride thereof with cyclopentadiene alone.

That is, the gist of the present invention is that (A) a thermal copolymer of a cyclopentadiene and an α-olefin and / or a monovinyl aromatic hydrocarbon or a hydride thereof having a softening point on a completed fluid basis. 5 to 30% by weight of a cyclopentadiene-based petroleum resin having a weight average molecular weight of not less than 40 ° C or 250 or more and (B) having a weight average molecular weight of 10
A traction drive fluid characterized in that 15 to 95% by weight of a branched polyalphaolefin having 0 to 1,000 is blended as an essential component.

Next, the present invention will be described in detail. The traction drive fluid of the present invention comprises a specific cyclopentadiene-based petroleum resin as the component A and a poly-α-olefin having a specific branch as the component B. The components are blended at a specific ratio as essential components.

The cyclopentadiene-based petroleum resin as the component A of the present invention is obtained by thermally copolymerizing a cyclopentadiene and an α-olefin and / or a monivinyl aromatic hydrocarbon, and further, if necessary, by a conventional method. Can be obtained.

The cyclopentadiene used in the present invention includes cyclopentadiene, a polymer thereof, an alkyl-substituted product thereof, and 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 such as naphtha.

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. It is preferable that the concentration of these olefins is low, but it is acceptable if the concentration is about 10% by weight or less per cyclopentadiene.

[0012] cyclopentadienes and copolymers raw material is alpha-C ₄ -C ₁₄ as olefins, 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 to mix this α-olefin in less than 4 moles per mole of cyclopentadiene.

Other monovinyl aromatic hydrocarbons which are copolymerization materials include styrene, o, m, p-vinyltoluene, α, β-methylstyrene and the like, and less than 3 moles per mole of cyclopentadiene. It is industrially preferable to mix them. The monovinyl aromatic hydrocarbons are can include indene, indene such as methyl indene or ethyl indene, is industrially advantageous to use a so-called C ₉ fraction obtained from steam cracking of naphtha is there.

It should be noted that the calculation is made as 1 mol when using a monomer such as cyclopentadiene as the cyclopentadiene, and as 2 mol when using a dimer.

One example of a thermal copolymerization method for obtaining a cyclopentadiene-based petroleum resin is as follows. For example, these cyclopentadienes and α-olefins and / or monovinyl aromatic hydrocarbons may be prepared at about 160 to 300 ° C. in the presence or absence of a solvent, preferably under an inert gas atmosphere such as nitrogen gas. About 18
The thermal copolymerization is carried out in a temperature range of 0 to 280 ° C. for about 0.1 to 10 hours, preferably for about 0.5 to 6 hours under a pressure capable of maintaining the raw material system in a liquid phase.

After distilling off the inactive components and unreacted raw materials in the raw materials and, if necessary, the solvent from the polymerization solution by distillation or the like under normal pressure or under pressure, the second stage polymerization is continued under reduced pressure for about 160 to 160. A desired cyclopentadiene-based petroleum resin can be obtained at 280 ° C. for about 0.5 to 4 hours.

The thermal copolymerization conditions are set so that the cyclopentadiene petroleum resin has a softening point of about 40 ° C. or more or a weight average molecular weight of about 250 or more. The cyclopentadiene-based petroleum resin shows an excellent compounding effect regardless of the presence or absence of the hydrogenation treatment. However, it is preferable to carry out a hydrogenation treatment in order to improve odor and stability and from the viewpoint of improving hue.

The hydrotreating can be carried out by a usual method. For example, using a hydrogenation catalyst such as nickel, palladium or platinum, in the presence or absence of a solvent, about 70%
~ 300 ° C, preferably about 100-250 ° C temperature range,
Hydrogen pressure about 10 to 200 kg / cm ² (G), preferably about 20 to
The hydrogenation may be performed under a pressure of 120 kg / cm ² (G) for about 0.5 to 20 hours, preferably for about 1 to 10 hours. After the hydrotreating, the catalyst and, if necessary, the solvent are removed to obtain the desired base material of the traction drive fluid.

The cyclopentadiene petroleum resin may have a softening point or a weight average molecular weight within the following range. The softening point is about 40 ° C. or more, preferably about 80 ° C. or more and about 180 ° C. or less. The average molecular weight is about 250 or more, preferably about 400 or more and about 2,000 or less.
If either the softening point or the molecular weight of the cyclopentadiene-based petroleum resin falls within this range, a sufficient traction coefficient can be obtained.

The amount of the cyclopentadiene-based petroleum resin is about 5 to 30% by weight, preferably 7 to 30% by weight, based on the finished fluid.
20% by weight. When the amount is too small, the traction coefficient is hardly improved, and when the amount is too large, the increase in viscosity becomes large.

The present invention relates to a cyclopentadiene-based petroleum resin comprising cyclopentadiene and α-olefin and / or
Or it is necessary to blend a thermal copolymer with monovinyl aromatic hydrocarbons or a hydride thereof, and the intended effect is not exhibited even if a thermal polymerized resin of cyclopentadiene alone or a hydride thereof is blended. .

Although the reason for this is not clear, a thermal copolymer of cyclopentadiene and an α-olefin and / or a monovinyl aromatic hydrocarbon or a hydride thereof is a thermal copolymer of cyclopentadiene alone or a thermal polymer thereof. It is considered that even if the temperature is increased due to a difference in molecular structure compared to the hydride, for example, bulkiness, the optimum oil film thickness that can increase the traction coefficient can be maintained.

The expression of the thermal copolymer resin or its hydride also includes a mixture of the thermal copolymer and its hydride.

The branched polyα-olefin which is the component B has a quaternary or tertiary carbon atom in the main chain. The raw material is not particularly limited as long as it is an olefin having 3 or more carbon atoms. In particular, isobutylene 1- to 4-mer and propylene 1- to 5-mer are suitably used. These olefins may be polymerized singly or as a mixture of two or more.

The branched poly-α-olefin as the component B may have a molecular weight in the range of 100 to 1,000, and particularly preferably those having a molecular weight of 150 to 500. The molecular weight of these poly-α-olefins is 100
If the molecular weight is smaller than the above, the evaporating property and the oil film holding ability are lowered.

The poly-α-olefin is incorporated in an amount of 15 to 95% by weight, preferably 20 to 90% by weight, based on the finished fluid. If the amount is less than 15% by weight, the low-temperature fluidity, the compatibility with the sealing material and the like deteriorate, which is not preferable.

When a poly-α-olefin having no branch such as polyethylene is used as the component B, the obtained traction coefficient is low, and the intended effect of the present invention cannot be obtained.

Although the traction drive fluid of the present invention has a sufficient effect only with the above-mentioned components A and B, it is necessary to add a commonly used base oil such as mineral oil or synthetic oil alone or as a mixture as other components. Can also. These are more desirable as the traction coefficient is higher. In particular, other components include cyclopentadiene or cyclopentadiene and at least one or more multimers obtained by thermal polymerization or thermal copolymerization of α-olefins and / or monovinyl aromatic hydrocarbons. A pentadiene-based condensed-ring hydrocarbon comprising cyclopentadiene-based dimer to hexamer as a main component, and a ratio of hydrogen amount on a norbornene ring double bond to hydrogen amount on a cyclopentene ring double bond (ND / C
D) is a polymer hydride of 0.9 to 1.3;
Those having a kinematic viscosity at 1 ° C. in the range of 1 to 200 cSt are preferably used.

The traction drive fluid of the present invention can be prepared by adding various additives such as an antioxidant and an antiwear agent in an amount of about 0.05 to 10% by weight depending on the use.

[0030]

In the traction drive fluid of the present invention, the cyclopentadiene-based petroleum resin and the branched poly-α-olefin are blended in a specific ratio, so that the advantages of each component appear complementarily by mixing the two. In this case, a satisfactory effect can be obtained in the performance of the present invention, and even when the third component is further added, the effect appears effectively.

That is, the cyclopentadiene-based petroleum resin, which is the component A of the present invention, maintains a high traction coefficient even at a high temperature because the molecule has a bulky three-dimensional structure even at a high temperature. The poly-α-olefin having a branch has a high traction coefficient due to the structural feature of having a quaternary or tertiary carbon atom in the main chain, and has a chain structure similar to a paraffinic mineral oil. It seems that the performance derived from the base oil such as compatibility is excellent. It is considered that the effects equivalent to those of the single component were exhibited without impairing the performance of each component even by mixing both or the third component.

It is considered that the reason why the traction drive fluid of the present invention has a particularly excellent traction coefficient is that the three-dimensional structure of the molecules of both components is significantly increased due to entanglement, and the compounding effect is synergistically exhibited.

[0033]

EXAMPLES The present invention will now be described specifically 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. Traction coefficient: using a four-cylinder friction tester, drive shaft rotation speed 1,000 rpm (2.09 m / s), slip rate 5
%, Normal load 114kg, test oil temperature 40 ℃ ～ 120 ℃
The ratio was expressed as the ratio of the transmitted tangential force to the normal load measured in. Sealing material compatibility: A test was performed using nitrile rubber at 120 ° C. for 100 hours in accordance with JIS K6301. The determination of the weight average molecular weight was performed by ordinary gel permeation chromatography using polystyrene as a standard substance, and the results were expressed in terms of polystyrene. That is, in the present invention, HLC manufactured by Tosoh Corporation
It was measured under the following analysis conditions using Model -802. Column: tetrahydrofuran (THF) Column bath temperature: 40 ° C. Flow rate: 1.2 ml / min Material concentration: 0.005 g / 1 ml THF Detector: Differential refractometer

The following reference example shows a production example of a cyclopentadiene-based petroleum resin blended in the fluid of the present invention. Reference Example 1 A CPD cut 500 composed of 75.0% by weight of dicyclopentadiene, 5.4% by weight of olefin and most of the remainder being a saturated hydrocarbon obtained from steam cracking of naphtha.
g (5.7 moles of cyclopentadiene) and naphtha by steam cracking, with a total content of styrene, vinyltoluene, α, β-methylstyrene and indene of 26.5% by weight (average molecular weight 118) and other large amounts. C ₉ aromatic fraction 5 consisting of partially inert aromatic hydrocarbons
00g (1.1 mole of reactive component) under nitrogen atmosphere
/ Cm ² (G) at 260 ° C. for 3 hours. The inert fraction in the raw materials and the unreacted raw materials are first distilled off from the thermal copolymer solution at 252 ° C. under pressure and then under reduced pressure.
50 Torr. 1 at the same temperature under reduced pressure
After holding for a time, 409 g of a cyclopentadiene resin having a softening point of 120 ° C. was obtained.

Next, 2% by weight of a nickel catalyst was added, and a hydrogen pressure of 60 kg / cm ² (G) and a reaction temperature of 250 ° C.
Hydrogenation was carried out for an hour to obtain a desired cyclopentadiene-monovinyl aromatic copolymer hydrogenated resin having a desired softening point of 125 ° C. and a weight average molecular weight of 640.

[0037] Reference Example 2 Reference Example CPD fraction 750g using (cyclopentadiene 8.5 mol) and includes decene 96.5 wt% Others consists fractions other than α- olefin C ₁₀ fraction 250
g (1.7 mol as α-olefin) was thermally copolymerized for 2 hours under the same conditions as in Reference Example 1. The inert fraction in the raw materials and the unreacted raw materials were distilled off from the hot copolymerization liquid at 200 ° C. under pressure and then under reduced pressure to obtain 380 g of cyclopentadiene resin. Next, hydrogenation was performed at 220 ° C. for 4 hours under the same conditions as in Reference Example 1, and the desired softening point was 32 ° C.
A cyclopentadiene-α-olefin copolymerized hydrogenated resin having a weight average molecular weight of 486 was obtained.

Examples 1 to 5 and Comparative Examples 1 to 5 As shown in Table 1, traction drive fluids were prepared. The results are shown in Table 2 and FIG. Example 1 above
5 and Comparative Examples 1 to 5, the traction fluid of the present invention (Examples 1 to 5) is a fluid containing neither cyclopentadiene-based petroleum resin and branched polyα-olefin (Comparative Examples 1 to 5). ) Has significantly better overall performance than any of the above.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

The traction drive fluid of the present invention has a high traction coefficient over a wide temperature range, so that it can always maintain a stable power transmission capacity, and can reduce the size and weight of the device and extend the life of the device. In addition, low temperature startability, evaporability,
The practical performance such as the hermeticity of the device can be improved. for that reason,
In particular, the present invention can be suitably used for a device having a large torque capacity such as a continuously variable transmission for an automobile and under severe use conditions. Also, since both the cyclopentadiene-based petroleum resin and the branched poly-α-olefin are inexpensive, the traction drive fluid of the present invention has excellent economic efficiency.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the temperature of a traction drive fluid and the traction coefficient in Examples 1 to 5, Comparative Example 1 and Comparative Examples 3 to 5, wherein the horizontal axis represents temperature (° C.) and the vertical axis represents traction coefficient. (Μ).

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10M 109/02 C10M 109/02 111/06 111/06 // C10N 20:00 20:02 30:08 40:04 (72) Inventor Katsumi Minomiya 5-9-1, Kimizuka, Ichihara-shi, Chiba (56) References JP-A-5-1292 (JP, A) JP-A-4-68084 (JP, A) JP-A-3-103495 (JP) JP-A-1-197594 (JP, A) JP-A-1-198692 (JP, A) JP-A-62-4785 (JP, A) JP-B-50-10322 (JP, B1) (58) Field surveyed (Int.Cl. ⁶ , DB name) C10M 111/04 C10M 105/04 C10M 105/06 C10M 107/02 C10M 107/14 C10M 109/02 C10M 111/06 C10N 40:04

Claims (1)

(57) [Claims] 1. A heat-treated copolymer of (A) a cyclopentadiene and an α-olefin and / or a monovinyl aromatic hydrocarbon, or a hydride thereof, having a softening point of 40 ° C. or higher or a weight average, based on a completed fluid. 5 to 30% by weight of a cyclopentadiene petroleum resin having a molecular weight of 250 or more and (B) 15 to 95% by weight of a branched polyα-olefin having a weight average molecular weight of 100 to 1,000 are blended as essential components. A traction drive fluid comprising: