JPH05105890A - Traction drive fluid - Google Patents

Abstract

PURPOSE:To obtain the title fluid having a high traction coefficient, a proper viscosity, and excellent oxidation stability and thermal stability by mixing a specified naphthene compound comprising a cyclopentadiene oligomer with a specified polybutene, etc. CONSTITUTION:A traction drive fluid which contains at least a naphthene compound having a weight-average molecular weight of 200 to 300, comprising a hydrogenated cyclopentadiene oligomer with a ratio of the content X of the double bond of the norbornene ring to the content Y of the double bond of the cyclopentene ring of (0.10:1) to (0.90:1); and a polybutene having a viscosity at 40 deg.C of 5-60cSt and/or a compound of the formula, wherein R1 to R4 are each independently of one another H, methyl or ethyl. The use of this traction drive fluid enables the realization of both the efficient transmission of drive force in a traction drive unit and a smaller traction drive unit.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to traction drive fluids. More specifically, the present invention relates to a traction drive fluid having a large traction coefficient and excellent in other performances.

[0002]

2. Description of the Related Art A traction drive fluid is interposed in a contact portion of a traction drive device [that is, a device for transmitting a driving force by point contact or line contact between rotating rigid bodies: for example, a continuously variable transmission for an automobile] to transmit power. It is a lubricating oil that prevents direct contact between rigid bodies. Such a fluid has a high viscosity when subjected to high pressure between rigid bodies,
As a result, a material is used that functions to efficiently transmit the power between rigid bodies, while immediately becoming an appropriate flow state when separated from the contact portion.

The most important indicator of the performance of this traction drive fluid is the traction coefficient. The larger the traction coefficient, the better the transmission of the driving force. In addition, the size of the traction drive device can be reduced accordingly.

Further, one of the performances desired for a traction drive fluid is that it exhibits an appropriate viscosity.
Because, if the viscosity is too high, the stirring loss will be large,
This is because the power transmission efficiency is low and the low temperature starting characteristic is also poor. On the other hand, if the viscosity is too low, it will be difficult to retain the oil film at high temperatures, and the seizure of the rigid body may occur.

Further, it is required to have other performances required for a normal lubricating oil, such as being stable against heat and oxidation.

In consideration of such requirements, Japanese Patent Laid-Open No. 1-2306
Japanese Unexamined Patent Publication No. 96 (hereinafter referred to as the first Japanese Unexamined Patent Publication) discloses a fluid containing a polymer hydrogenated product of dicyclopentadiene and / or dihydrodicyclopentadiene and having a weight average molecular weight of 250 or more. In this publication, the weight average molecular weight is 32.
A fluid using 0,540 polymer hydrogenates is specifically disclosed and only its traction coefficient is indicated.
Further, JP-A-1-197594 (hereinafter referred to as "second publication")
Has proposed a cyclopentadiene-based traction drive fluid, which is a mixture of a cyclopentadiene-based trimer and a hexamer and has a norbornene ring double bond amount X and a cyclopentene ring double bond amount Y. Ratio X / Y is 0.9
It is a hydrogenated product of ~ 1.3 and a viscosity at 40 ° C of 1 ~ 200 cSt.

[0007]

At present, in order to transmit a higher driving force in a traction drive device, to downsize the traction drive device, and to obtain an easy-to-use traction drive fluid, the above first and second aspects are provided. There is a demand for a traction drive fluid that is more excellent in balance of traction coefficient and viscosity than the fluid for traction drive disclosed in the publication and that also satisfies the above-mentioned various performances.

An object of the present invention is to provide a traction drive fluid that can solve the above problems.

[0009]

The first aspect of the present invention, which has been made to achieve the above object, is an oligomer of cyclopentadiene having a norbornene ring double bond amount X and a cyclopentene ring double bond amount Y. Ratio X / Y is 0.10 to 0.90
The weight average molecular weight of the hydrogenated product is 200 to 300
Is a traction drive fluid containing at least the naphthene compound (1) and polybutene having a viscosity at 40 ° C. of 5 to 60 centistokes (cSt). Similarly, the second invention is a weight average molecular weight of a hydrogenated product of an oligomer of cyclopentadiene having a ratio X / Y of the norbornene ring double bond amount X and the cyclopentene ring double bond amount Y of 0.10 to 0.90. It is a traction drive fluid containing 200 or more and less than 250 naphthene compounds.

The traction drive fluid of the present invention (the first and second inventions) has a high traction coefficient value, has an appropriate viscosity, and is excellent in other performances.

As described above, in the first invention, "a weight average molecular weight (hereinafter, simply referred to as a molecular weight) of a hydrogenated product of an oligomer of cyclopentadiene, a naphthene compound having 200 to 300 (hereinafter referred to as a predetermined naphthene compound) ) ”
Used as an essential ingredient. Unlike the one specifically disclosed in the first publication (molecular weight 320,540), the molecular weight is 200 to 300.
Is important to the present invention (as described below). The predetermined naphthene compound does not have to be a single compound, and may be any compound as long as it shows a value within the above-mentioned predetermined range when the average molecular weight is measured. The molecular weight can be calculated from a mass spectrum or the like.

Further, unlike the one disclosed in the second publication, which is mainly composed of a cyclopentadiene-based trimer to hexamer, which has no specific molecular weight, in the first invention, a cyclopentadiene oligomer The naphthene compound consisting of hydrogenated product is
The molecular weight is specified as the above-mentioned predetermined molecular weight range (200 to 300), and therefore, the oligomer hydrogenated product is mainly composed of cyclopentadiene trimer and tetramer (the structure can take various modes). Is important (as described below). It is preferably those containing 70% or more, and particularly preferably containing 75% or more. However, the predetermined naphthene compound may contain a small amount of other oligomer hydrogenated products such as pentamers in addition to the trimers and tetramers. When the pentamer or higher oligomer hydrogenated substance is the main component, its molecular weight deviates from the above molecular weight and tends to be resinous, but if it does not deviate from the above predetermined molecular weight range as a whole,
The pentamers and the like may be mixed in the predetermined naphthene compound. When the hydrogenated product is a dimer or less, its molecular weight deviates from the above-mentioned molecular weight and the traction coefficient becomes low. It may be mixed in the product.

The tetramer hydrogenated product is represented by the chemical formula (I)
The compound represented by (IV), that is, the compound in which cyclopentadiene is hydrogenated after repeating the Diels-Alder reaction ((I)) or a part of the condensed ring of (I) due to a normal addition reaction Compounds having a cleaved structure ((II) to (IV)) and the like can be mentioned. This has been clarified from the results of mass spectrum and the like.

[0014]

[Chemical 2] The hydrogenated trimer is one obtained by removing one cyclopentadiene from the above various tetramers.

In the first invention, the viscosity at 40 ° C. is 5
Polybutene of 60 cSt (hereinafter referred to as a predetermined polybutene) is used as another essential component. In the present specification, polybutene is meant to include hydrogenated products thereof.
The polybutene is preferably polyisobutylene and can be represented by the following structural formula.

[0016]

[Chemical 3] The hydrogenated product is represented by the following structural formula.

[0017]

[Chemical 4] However, the above-mentioned degree of polymerization n is such a value that the viscosity at 40 ° C becomes 5 to 60 cSt.

As polyisobutylene, a commercially available product may be used, but it can also be produced by a known polymerization method. The hydrogenated product is produced by reacting polyisobutylene or the like in the presence of hydrogen.

The reason why the naphthene compound having a specific molecular weight and the polybutene having a specific viscosity are used in the first invention will be described with reference to FIG.

FIG. 1 is an explanatory view of the first invention, in which the horizontal axis represents the viscosity of polybutene at 40 ° C. and the vertical axis represents the molecular weight of the naphthene compound. The area A indicates the range of the first invention. The other regions are regions outside the first invention. In other words, B (the molecular weight of the naphthene compound is 20
(Region including less than 0), C (molecular weight of naphthene compound is 22
A value of 00 or more and a viscosity of polybutene of less than 5 cSt), D (the molecular weight of the naphthene compound exceeds 300 and the viscosity of polybutene of 5 to 60 cSt), and E (the viscosity of polybutene exceeds 60 cSt). ) Indicates a region outside the present invention.

In regions B and D, the traction coefficient is low. In the C range, the thermal stability and the oxidation stability are poor. In the E region, a lubricating oil having an appropriate viscosity cannot be obtained. In the region A, there is no such drawback, a high traction coefficient and an appropriate viscosity can be obtained, and the thermal stability and the oxidation stability are also good. Thus, the area A is the first invention of the present invention.

Further, in the first invention, the combination of the predetermined naphthene compound and the predetermined polybutene is based on the following three reasons. First of all, the predetermined naphthene compound alone,
When the specified polybutene is mixed, it is possible to avoid that the viscosity of the mixture is in a practically inappropriate range (about 160 cSt or more at 40 ° C), regardless of the molecular weight of the specified naphthene compound. Because. Moreover,
This is because the mixing ratio in that case can take a wide range and the mixing is easy. Second, the traction coefficient is not so high when the predetermined polybutene is used alone (the coefficient:
0.078), which is not preferable. Then, the more important third reason will be described with reference to FIG. In this figure, the horizontal axis shows the mixing ratio of the predetermined naphthene compound and the predetermined polybutene, and the vertical axis shows the traction coefficient. The traction coefficient of the predetermined naphthene compound alone is 0.1047, and the traction coefficient of the predetermined polybutene alone is
It is 0.078, and the traction coefficient when the two are mixed is estimated to be as shown by the dotted line in the figure. But,
In fact, the traction coefficient when the two are combined is shown by the solid line. In this way, by mixing the two, the traction coefficient became larger than expected, and a synergistic effect was observed.
This is an important reason for combining the two.

In the first aspect of the present invention, the molecular weight is 200
A mixture of up to 250 predetermined naphthene compounds and predetermined butenes is particularly excellent in the overall balance of traction coefficient and viscosity.

In the first aspect of the present invention, if the mixing ratio of the predetermined naphthene compound and the predetermined polybutene is appropriately selected, the viscosity can be simplified to a practically appropriate value. Its value is usually 10
~ 80cSt, preferably 10-60cSt, more preferably 15-
It is 55cSt.

On the other hand, the second invention may use a hydrogenated product of an oligomer of cyclopentadiene alone. This gives a high traction coefficient and a moderate viscosity. However, the molecular weight of hydrogenated product (naphthene) is therefore
It must be 200 or more and less than 250. If the molecular weight is lower than the lower limit, the traction coefficient is small, and if the molecular weight is higher than the upper limit, the viscosity of the naphthene alone becomes unacceptable for practical use. To construct a naphthene having such a molecular weight range, it is sufficient to use a tri- and tetra-mer as the center, as described above. The second aspect of the present invention is particularly excellent in terms of economic efficiency and ease of preparation because the hydrogenated product may be used alone.

The predetermined naphthene compound in the first invention and the naphthene compound used in the second invention may be obtained by any method, but it is economical to obtain them by-products in the production of petroleum resin. It is also preferable for convenience. In a typical petroleum resin production method, dicyclopentadiene is thermally polymerized, then hydrogenated, and then separated and purified into petroleum resin, hydrogenated product of oligomer of cyclopentadiene, and others (in this step, Since the details are well known to those skilled in the art, further description will be omitted). The hydrogenated product of the cyclopentadiene oligomer is further dried by heating and used as it is, or a high boiling point component (boiling point 150-180 ° C / 2 mmHg) and a low boiling point component (boiling point 11) in order to adjust the viscosity.
(0-150 ° C./2 mmHg) and may be used after being separated by distillation.

The traction drive fluid of the present invention contains various additives such as an antioxidant, a viscosity index improver, a metal deactivator, an antiwear agent, a rust preventive and an antifoaming agent for the purpose of further improving its performance. May be added.

For a given naphthenic compound of the present invention, other traction drive fluids, or other types of lubricants, for example, for the balance of action effect requirements and other performance requirements, or for other reasons, such as A wide variety of liquid substances such as paraffinic mineral oil, naphthenic mineral oil, hydrocarbons such as alkylbenzene, poly-alpha-olefin and synthetic naphthene, and oxygen-containing compounds such as ester and ether may be blended.

For example, a compound represented by the following general formula (A) is (1) an oligomer of cyclopentadiene (the ratio X / Y of the norbornene ring double bond amount X and the cyclopentene ring double bond amount X is 0.10 to 0.90). A naphthene compound having a weight average molecular weight of 200 to 300, or a hydrogenated product of
(1) A traction drive fluid containing at least a polybutene having a viscosity of 5-60 centistokes at 40 ° C., or an oligomer of cyclopentadiene (a norbornene ring double bond amount X and a cyclopentene ring double bond amount Y).
Having a ratio X / Y of 0.10 to 0.90) and a naphthene compound having a weight average molecular weight of 200 or more and less than 250, which has an appropriate viscosity and maintains a high traction coefficient. The evaporation loss of the entire traction drive fluid can be suppressed. That is, high performance is maintained and loss of traction drive fluid can be prevented.

General formula (A)

[0031]

[Chemical 5] [In the formula, R _{1 to} R ₄ are each independently hydrogen, a methyl group, or an ethyl group.] Especially, in the above formula, _one in which two of R _{1 to} R ₄ are hydrogen maintains a high traction coefficient. It is preferable in meaning. The compound of the general formula (A) is not only added to the first invention and the second invention, but is also an oligomer of cyclopentadiene and has a ratio of the norbornene ring double bond amount X to the cyclopentene ring double bond amount Y. X / Y
Weight average molecular weight consisting of hydrogenated products of 0.10 to 0.90
By adding 200 to 300 naphthenic compounds or hydrogenated products of cyclopentadiene oligomers to a traction drive fluid as a base oil, excellent traction coefficient, viscosity, oxidative stability, etc. were obtained as in the first and second inventions. It is possible to suppress the evaporation loss of the traction drive fluid.

[0032]

EXAMPLES The present invention will now be described in more detail with reference to typical examples.

Examples 1 and 2 Predetermined naphthene compounds having an average molecular weight of 280 (84% of cyclopentadiene tetramer hydrogenated product, the rest being trimers, pentamers and others, norbornene ring double bond content X / The ratio of the cyclopentene ring double bond amount Y / X = 0.59) and the viscosity at 40 ° C
A mixture ratio of 11.0 cSt of polybutene [polyisobutylene (Polybutene NAS-5H manufactured by NOF CORPORATION) 63:37]
To prepare a traction drive fluid (Example 1). Further, a predetermined naphthene compound having an average molecular weight of 231 (cyclopentadiene tetramer hydrogenated product 36%, trimer hydrogenated product 60%
%, The rest are pentamers and others, the above X / Y = 0.30)
And the same polybutene as above were mixed at a mixing ratio of 85:15 to prepare a traction drive fluid (Example 2).

The reason why the mixing ratio of the predetermined naphthene and isobutylene is selected as described above is that the viscosity of the mixed fluid is practically particularly preferable from the viewpoints of transmission efficiency and oil film retention characteristics.
This is to keep it around ~ 25cSt.

Physical properties of the composition obtained (viscosity at 40 ° C., 10
The viscosity at 0 ° C. and the viscosity index) are shown in Table 1. The molecular weight is determined by mass spectrometry and the viscosity is measured according to JIS K 2283.
It was measured by. Regarding thermal stability and oxidative stability,
It was measured by the methods specified in JIS K 2540 and JIS K 2514, respectively.

The traction coefficient of the obtained fluid was measured as follows. A Soda 4-roller traction tester was used as the measuring device, and the test conditions were: oil temperature 30 ° C, roller temperature 30 ° C, average Hertz pressure 1.2GPa, rolling speed 3.6.
The m / s and slip rate were 3.0%. Under this condition, the traction coefficient becomes maximum at a slip ratio of about 3% in any oil, so the measured traction coefficient may be regarded as the maximum traction coefficient. The value of the obtained traction coefficient is also shown in Table 1.

Comparative Examples 1 to 5 Compositions of the components shown in Table 1 were prepared at the mixing ratios shown in Table 1, and physical properties, oxidation stability / heat stability and traction coefficient were examined in the same manner as in Example 1. It was The results are also shown in Table 1. The specified mixing ratio is such that the viscosity of the lubricating oil composition is about 20 to 25 cSt which is practically particularly preferable, in other words, the viscosity can be compared with that of Example 1 within the range where the viscosity is practically particularly preferable, It is a choice. Comparative examples 1, 2, 3, 4, and 5 are D, D, B, and
In the C and E regions, Comparative Example 4 in the C region has poor thermal stability and oxidation stability at any mixing ratio, and in Comparative Example 5 in the E region, Even with the mixing ratio, a suitable viscosity (10 to 60 cSt) could not be obtained. Incidentally, the proportion of the tetramer of the naphthene compound used in Comparative Example 1 was 10%, Comparative Example 2 was 2%, and Comparative Example 3 was 1%.
%.

[0038]

[Table 1] As is clear from the evaluation table 1, Example 1 according to the first invention,
The composition of No. 2 has a better traction coefficient than the other Comparative Examples 1 to 5. Comparative Examples 1 and 2
Regarding the naphthene compound, it seems that it corresponds or approximates to the one disclosed in the above-mentioned first publication in which the one having a molecular weight of 320 or 540 is used, but a good result can be obtained by comparison therewith. .. And the thing of Examples 1 and 2 was also high in oxidation stability and heat stability.

Examples 3 to 5 The components shown in Table 2 were prepared in the mixing ratio shown in Table 2,
Physical properties, oxidation stability / heat stability, and traction coefficient were examined in the same manner as in Example 1. The results are also shown in Table 2.

The predetermined naphthene compounds used in Examples 3 and 5 are as follows. Cyclopentadiene tetramer hydrogenated product is 75%, the rest is trimer, pentamer or the like, and the above X / Y = 0.41. Example 4
The predetermined naphthene compound used in Example 1 is the same as that used in Example 1.

As can be seen from the above, the traction coefficient is high, and the oxidation stability and thermal stability are good.

[0042]

[Table 2] Example 6 The following fractions (A) and (B) of the high boiling point fraction and the low boiling point fraction obtained by fractionally distilling a predetermined naphthene compound by vacuum distillation
Was mixed at a ratio of 53:47 to prepare a traction drive fluid.

The assembly formed (%) 40 ° C. Viscosity 100 ° C. Viscosity Viscosity Index Trimer Tetramer Others fraction (A) 10.25 2.63 82.9 96.8 3.2 - Fraction (B) 255.0 11.26 (-) 89.6 0.1 99.2 0.7 this compound, 40 ℃ / 100 ℃ Viscosity = 23.36 / 4.07, Viscosity index = 46.5, Weight average molecular weight 238, Traction coefficient = 0.10.
10, X / Y = 0.43, oxidation stability and heat stability were good.

Examples A1 to A4 Fraction (A) : Fraction (B) 40 ° C. Viscosity molecular weight X / Y Examples A1 30: 70 65.90 247 0.43 Examples A2 30: 70 65.90 247 0.43 Examples A3 0: 100 255.0 268 0.43 Example A4 30: 70 65.90 247 0.43 Each cyclopentadiene oligomer hydrogenated product in the above table was mixed with bicyclohexyl, ethylbicyclohexyl or triethylbicyclohexyl in a ratio shown in the above table, and 40
Traction drive fluids were prepared so that their kinematic viscosities at ℃ were similar and preferred for practical use, and their traction coefficient and evaporation loss were investigated. The traction coefficient was determined in the same manner as in Example 1, and the evaporation loss was examined by using a thermobalance to determine the weight loss ratio of each traction drive fluid after holding at 120 ° C. for 5 hours. The results are shown in the table below.

Reference Example A1 Cyclopentadiene oligomer hydrogenated product (fraction (A): fraction (B) = 64: 36, viscosity at 40 ° C. is 25.97 cSt, molecular weight 226, X / Y is 0.43) and evaporation I investigated the loss. The results are also shown in the table below.

[0046]

[Table 3] Evaluation As is clear from the comparison between Examples A1 to A4 and Reference Example A1, when the compound represented by the general formula (A) is added, the evaporation loss is maintained while maintaining a high traction coefficient and an appropriate viscosity. Can be reduced.

[0047]

As described above in detail, the traction drive fluid of the present invention has an improved traction coefficient and has a desirable value of viscosity (from the viewpoints of transmission efficiency, low temperature startability, oil film property retention, etc.). be able to. Moreover, it is also excellent in other performances required as a lubricating oil, such as oxidation stability and thermal stability. By using this, in particular, the following points, namely, the efficiency of the transmission of the driving force in the traction drive device and the miniaturization of the traction drive can be further improved.

Further, when the compound represented by the general formula (A) is used, the evaporation loss can be reduced and the useless loss can be reduced.

Among the present inventions, particularly the first invention is
An appropriate viscosity can be easily obtained in a state where a high traction coefficient is obtained by the synergistic action of a predetermined naphthene and polybutene. The second invention can constitute a traction drive fluid having a high traction coefficient with a single component. As a result, it is inexpensive and very easy to prepare.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the present invention.

FIG. 2 is an explanatory diagram for explaining the reason why a predetermined naphthene compound and a predetermined polybutene are combined in the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C10M 107: 08) (C10M 109/02 105: 04) C10N 20:02 30:06 30:08 30 : 10 40:04 60:02 (72) Inventor Takehisa Sato 1-3-1 Nishitsurugaoka, Oi-cho, Iruma-gun, Saitama Prefecture Tonen Corporation Research Institute (72) Hirotaka Tomisawa Nishitsurugaoka, Oi-cho, Saitama Prefecture 1-3-1 Tonen Co., Ltd. Research Institute

Claims (3)

[Claims] 1. A weight-average molecular weight of a hydrogenated product of cyclopentadiene oligomer having a ratio X / Y of norbornene ring double bond amount X to cyclopentene ring double bond amount Y of 0.10 to 0.90 and a weight average molecular weight of 200 to 300. Naphthene compound of
A traction drive fluid containing at least a polybutene having a viscosity at 40 ° C. of 5 to 60 centistokes and / or a compound represented by the following general formula (A). General formula (A): [In the formula, R _{1 to} R ₄ are each independently hydrogen, a methyl group, or an ethyl group] 2. A weight average molecular weight of a hydrogenated product of cyclopentadiene oligomer having a ratio X / Y of the norbornene ring double bond amount X to the cyclopentene ring double bond amount Y of 0.10 to 0.90 and a weight average molecular weight of 200 or more and 250 or more. Traction drive fluid containing less than naphthenic compounds. 3. The traction drive fluid according to claim 2, wherein the compound represented by the general formula (A) is added and mixed.