JPH0753870B2 - Fluid composition for traction drive - Google Patents

Description

TECHNICAL FIELD The present invention relates to a traction drive fluid composition, and more particularly to a traction drive fluid composition having excellent traction coefficient and high temperature characteristics.

PRIOR ART Traction drive devices such as hole & cone type, cone & ring type, wheel & disc type, tube & sheave type,
In the power transmission part of a towing drive device such as a toroidal type or planetary roller type, power is transmitted by using rolling friction that occurs when the oil film of the lubricating oil hardens on the rolling contact surface, so the lubrication used there. The agent, that is, the fluid for traction drive, is required to have excellent power transmission capability, that is, high traction coefficient.

At the same time, the traction drive fluid is exposed to extremely high temperature conditions during high-speed operation of the traction drive device, so that an oil film can be formed on the friction surface even under high temperature conditions. It is required to have a low viscosity and have a viscosity of a certain level or higher even at a high temperature.

Conventionally, regarding fluids for traction drive,
For example, Japanese Examined Patent Publication Nos. 46-338, 46-339, 47-7664,
48-29715, 48-42067, 48-42068, 53
-36105, 58-12319, 58-27838, 60-135
No. 3, No. 60-1354, No. 60-19951, No. 60-43391,
Various compounds have been proposed in various patents and literatures including No. 60-43392.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, the known traction drive fluids shown above are not practically used due to reasons such as difficulty in obtaining raw materials, complicated manufacturing method, and traction coefficient not suitable for practical use. Slightly proposed in Japanese Patent Publication Nos. 53-36105 and 58-12319, 2,4-dicyclohexyl-
2-Methylpentane is practically used as a fluid as it is or as a grease by adding a thickener to it.

However, although this 2,4-dicyclohexyl-2-methylpentane has an excellent traction coefficient,
Under high temperature conditions, there are drawbacks such as large evaporation loss and low viscosity.

As a result of repeated studies to overcome the drawbacks of the above-described conventionally known traction drive fluids, the present inventors have found that a composition obtained by mixing a compound having a specified structure and property in a specific ratio is used for a traction drive. As a fluid, they have found that they have various excellent properties, and have completed the present invention.

It is an object of the present invention to provide a traction drive fluid composition having a high traction coefficient and excellent high temperature characteristics, that is, a small amount of evaporation loss under high temperature conditions and excellent viscosity characteristics.

Means for Solving the Problems The present invention provides one or more alkyl aromatic compounds selected from the group consisting of (I) (A) alkylbenzene, (B) alkylnaphthalene, and (C) diphenylalkane. Yes, kinematic viscosity at 40 ° C is 2-40cSt
20-80% by weight, and (II) general formula (In the formula, n represents an integer of 0 or 1, and R ₁ and R ₂ are R ₁
= H, R ₂ = CH ₃ , and R ₁ = CH ₃ R ₂ = H. The present invention provides a fluid composition for traction drive, characterized in that it comprises a mixture of polycyclohexylalkane represented by the formula (1) and 80 to 20% by weight.

Hereinafter, the content of the present invention will be described in more detail.

The component (I) referred to in the present invention is one or more alkylaromatic compounds selected from the group consisting of (A) alkylbenzene, (B) alkylnaphthalene and (C) diphenylalkane. Viscosity 2-40
It is from cSt. As the (A) alkylbenzene, (B) alkylnaphthalene and (C) diphenylalkane used as the component (I) of the present invention, any one can be used as long as it satisfies the above-mentioned characteristics. For example, the following compounds are preferably used.

That is, (A) alkylbenzene has the general formula Compounds represented by are preferred. In the above formula, R ₃ has 6 carbon atoms
~ 18, preferably 9 ~ 15 alkyl group, R ₄ represents a methyl group or an ethyl group, a represents an integer of 1 or 2, b represents an integer of 0 to 2, preferably 0. The alkylbenzene represented by the above formula is, for example, benzene,
Aromatic compounds such as toluene, xylene, and ethylbenzene, preferably benzene, having 6 to 18 carbon atoms, preferably 9
It can be easily obtained by subjecting a branched or straight chain olefin of -15 to an alkylation reaction as an alkylating agent.

Examples of the (A) alkylbenzene used as the component (I) of the present invention include alkylation of benzene with a branched olefin such as propylene trimer obtained by low polymerization of propylene, propylene tetramer, propylene pentamer and a mixture thereof. By branched alkylbenzenes (monoalkylbenzenes, dialkylbenzenes and mixtures thereof) obtained, and by alkylation reaction of linear olefins obtained by dehydrogenating n-paraffins having 8 to 16 carbon atoms from kerosene with benzene The linear alkylbenzenes obtained (monoalkylbenzenes, dialkylbenzenes and mixtures thereof) and mixtures thereof are particularly preferably used.

Further, as (B) alkylnaphthalene, a compound represented by the general formula Compounds represented by are preferred. In the above formula, R ₅ has 3 carbon atoms
~ 22, preferably 10 ~ 20 alkyl groups, and c represents an integer of 1 or 2, preferably 1. The alkylnaphthalene represented by the above formula can be easily obtained by subjecting a branched or linear olefin having 3 to 22 carbon atoms, preferably 12 to 20 carbon atoms, to naphthalene as an alkylating agent to carry out an alkylation reaction. .

Examples of the alkylnaphthalene (B) used as the component (I) of the present invention include linear olefins having 10 to 20 carbon atoms, specifically, decene, dothecene, tetradecene, hexadecene, octadecene, eicosene and mixtures thereof, and naphthalene. The monoalkylnaphthalene obtained by the alkylation reaction of is particularly preferably used.

Further, as the (C) diphenylalkane, a compound represented by the general formula Compounds represented by are preferred. In the above formula, R ₆ has 1 carbon atom
To 3, preferably 2 alkylene groups, R ₇ and R ₈ each represent an alkyl group having 1 to 3 carbon atoms, preferably 1 to 2 carbon atoms, and d and e are 0 to 2, preferably an integer of 1 or 2. Is shown. Specifically, for example, R ₆ is a methylene group,
1,1-ethylene group _{[-CH (CH 3) -]} , 1,2- ethylene group _{[-CH 2 CH 2 -],} 1,1- propylene group [-CH (CH ₂ CH ₃₎
-], 1,2-propylene group _{[-CH (CH 3) CH 2} -], 2,2-
Propylene group _{[-C (CH 3) 2 -} ], 1,3- propylene group _{[-CH 2 CH 2 CH 2 -} ] and the like, also R _7, as R ₈ is methyl, ethyl, n- Examples include propyl group and isopropyl group. The diphenylalkane represented by the above formula is, for example, benzyl chloride, phenethyl chloride, α-methylbenzyl chloride, α, α-dimethylbenzyl chloride, α-ethylbenzyl chloride,
By alkylating an aromatic compound such as α-methylphenethyl chloride, β-methylphenethyl chloride, phenylpropyl chloride, styrene, α-methylstyrene, etc. as an alkylating agent with benzene, toluene, xylene, ethylbenzene, propylbenzene, etc. Can be easily obtained.

The (C) diphenylalkane used as the component (I) of the present invention is preferably a diphenylalkane having an asymmetric alkyl group substitution position, which is obtained by an alkylation reaction of styrene with toluene, xylene, ethylbenzene, or a mixture thereof. 1-Tolyl-1-phenylethane, 1-xylyl-1-phenylethane, 1-ethylphenyl-1-phenylethane, benzyltoluene, ditolylmethane and mixtures thereof are particularly preferably used.

Further, as the component (I) of the present invention, an alkyl aromatic mixture in which two or more kinds of compounds selected from the above-mentioned (A) alkylbenzene, (B) alkylnaphthalene and (C) diphenylalkane are mixed in an arbitrary ratio Can also be used.

On the other hand, the component (II) in the present invention is a compound represented by the general formula Is a polycyclohexylalkane. In the above formula, n represents an integer of 0 or 1, and R ₁ and R ₂ are R ₁ = H
And R ₂ = CH _{3 in the case of} and R ₂ = H in the case of R ₁ = CH ₃ , respectively.

This (II) component polycyclohexylalkane is
For example, polymerizing α-methylstyrene or poly-
It can be produced by thermally decomposing α-methylstyrene to obtain triphenylalkane or tetraphenylalkane, and then subjecting these to nuclear hydrogenation. Specifically, for example, the polymerization of α-methylstyrene is carried out by acid clay,
Activated clay, silica-alumina, montmorillonite type viscosity,
This can be easily carried out by using a solid acid catalyst such as silica gel, and using this together with an oxygen-containing compound such as water, a dihydric alcohol or an ether as a reaction modifier, and reacting with α-methylstyrene under heating. Further, the nuclear hydrogenation reaction is carried out by using a nuclear hydrogenation catalyst such as nickel, nickel-diatomaceous earth, Raney-nickel, platinum, platinum-alumina, rhodium, or rhodium-alumina to heat the above polyphenylalkane at high temperature and high pressure. It can be easily performed by contacting with hydrogen.

The polycyclohexylalkane obtained by the above method is
Depending on the conditions, those having a structure other than the component (II) of the present invention (dicyclohexylalkane, pentacyclohexylalkane, cyclic compound, etc.) may be mixed as a by-product, so a separation operation such as distillation may be carried out if necessary. Thus, the target compound can be taken out.

In the fluid composition for traction drive of the present invention,
The mixing ratio of the (I) component and the (II) component is (I) component 20-
The amount of component (II) is 80 to 20% by weight, preferably 70 to 30% by weight, relative to 80% by weight, preferably 30 to 70% by weight.
When the mixing ratio of the component (I) is less than the above range, the viscosity of the composition becomes too high, and particularly the component (II) alone is semisolid at room temperature and cannot be put to practical use. On the other hand, when the mixing ratio of the component (I) exceeds the above range, the high temperature characteristics and the traction coefficient of the composition become low, which is not preferable.

In the present invention, by mixing the components (I) and (II) in a specific ratio, a traction drive fluid excellent in various performances can be obtained, but within a range that does not impair the low temperature characteristics and the high temperature characteristics. -Dicyclohexyl-2-
It can also contain methylpentane. The content of this 2,4-dicyclohexyl-2-methylpentane is optional, but usually 100 parts by weight or less, preferably 50 parts by weight or less, relative to 100 parts by weight of the polycyclohexylalkane as the component (II).
It is less than or equal to parts by weight. This 2,4-dicyclohexyl-2-
When methylpentane is used in combination, the component (I) and the component (II) of the present invention are mixed to obtain a fluid composition for traction drive according to the present invention, and then 2,4-dicyclohexyl-2-methylpentane is obtained. May be mixed. In addition, as described above, when the component (II) is produced by polymerizing α-methylstyrene, 2,4-dicyclohexyl-2-methylpentane is also by-produced in addition to the component (II) depending on the reaction conditions. 2,4-dicyclohexyl-2-
The methylpentane may be mixed with the component (I) in the form of a mixture with the component (II) without separation and removal.

As described above, when the component (II) is produced by polymerizing α-methylstyrene, a cyclic compound (a cyclic dimer or a cyclic trimer of α-methylstyrene) may be added to the component (II) depending on the reaction conditions. And a cyclic tetramer nuclear hydrogenated product) may be by-produced, but these cyclic compounds may be contained in the traction drive fluid composition of the present invention within a range that does not impair the effects of the present invention. .

Further, various lubricating oil additives which are usually used can be added to the traction drive fluid composition of the present invention, if necessary. Specifically, for example, hindered phenols such as 2,6-di-t-butyl-p-cresol, aromatic amines such as phenyl-α-naphthylamine, organometallic compounds such as zinc dialkyldithiophosphate, sulfides and disulfides. Antioxidants represented by sulfur compounds such as carboxylic acids, sulfonic acids, phosphates, amines, alcohols, rust inhibitors such as esters, organic sulfur compounds, organic halogen compounds, zinc dialkyldithiophosphates, dialkyldithiophosphorus Addition of organic metal salts such as molybdenum acid and molybdenum dialkyldithiocarbamate, extreme pressure agents such as phosphoric acid esters, viscosity index improvers such as polymethacrylate and polyisobutylene, and defoaming agents such as silicone oil. it can. The addition amount of these known lubricating oil additives is also optional, but usually,
The total content is 20% by weight or less based on the total amount of the composition,
It is desirable to add it so that it is preferably 10% by weight or less.

Further known organic or inorganic thickeners for grease, specifically, for example, soap thickeners such as lithium soap, sodium soap, calcium soap, lithium complex soap, calcium complex soap, aluminum complex soap, etc. A non-soap thickener such as complex soap thickener, organosiloxane, terephthalamate, polyurea, organically treated clay, silica aerogel, etc. is mixed with the fluid composition for traction drive of the present invention and used as a traction grease. You can also The amount of the thickener mixed when used as a traction grease is arbitrary, but the content of the thickener is usually 1 to 30% by weight, preferably 3 to 20% by weight based on the total amount of the grease composition. Mixing is preferred.

Examples of the Invention Hereinafter, the contents of the present invention will be described more specifically with reference to Examples and Comparative Examples.

Examples 1 to 4 and Comparative Examples 1 to 5 By the compositions shown in Table 1, traction drive fluid compositions (Examples 1 to 4) according to the present invention were obtained. In addition, Table 1
The components shown in 1 have the following properties.

(I) Component Alkylbenzene 1; Linear alkylbenzene (monoalkylbenzene and monoalkylbenzene) obtained by alkylation reaction of benzene with a linear olefin having 10 to 14 carbon atoms obtained by dehydrogenating n-paraffin obtained from kerosene Mixture of dialkylbenzenes). Kinematic viscosity 26.2cSt (@ 40 ℃), flash point 202 ℃, average molecular weight 32
0.

Alkylbenzene 2; Branched alkylbenzene (mixture of monoalkylbenzene and dialkylbenzene) obtained by an alkylation reaction of a mixture of propylene tetramer and propylene pentamer with benzene. Kinematic viscosity 33.5 cSt (@ 40 ℃), flash point 160
° C, average molecular weight 318.

Alkylnaphthalene; Monoalkylnaphthalene mixture obtained by alkylation reaction of 1-hexadecene, 1-octadecene mixture and naphthalene. Kinematic viscosity 31.1 cSt (@ 40 ℃), flash point 230
C., average molecular weight 364.

Diphenylalkane; 1-xylyl-1-phenylethane, 1-ethylphenyl-1-phenylethane mixture obtained by alkylation reaction of styrene with xylene and ethylbenzene mixture. Kinematic viscosity 5.9cSt (@ 40 ℃), flash point 150 ℃, average molecular weight 212.

Component (II) Polycyclohexylalkane; Fraction with boiling point of 415 to 430 ° C (converted to normal pressure) obtained by nuclear hydrogenation of a product obtained by polymerizing α-methylstyrene with activated clay as a catalyst using a nickel catalyst. . It is semi-solid at room temperature (20 ℃), (R ₁ = CH ₃ , R ₂ = H or R ₁ = H, R ₂ = CH ₃ ) is the main component (content 95% by weight).

The following performance evaluation tests were conducted on the compositions of Examples 1 to 4, and the results are also shown in Table 1.

Performance evaluation test [High temperature viscosity] 100 according to the kinematic viscosity test method specified in JIS K 2283.3.
The kinematic viscosity at ° C was measured.

[Evaporation loss amount] Evaporation loss amount (weight reduction) of oil after heating at 120 ° C for 100 hours according to the lubricating oil thermal stability test method specified in JIS K 2540
Was determined in% by weight.

[Traction coefficient] 1,500 rpm, load 92.5 using a four cylinder rolling friction tester
It was measured under the conditions of kg / mm ² and a slip rate of 2%.

For comparison, a case where only the component (I) is used (Comparative Examples 1 to 4) and a case where 2,4-dicyclohexyl-2-methylpentane widely used as a traction drive fluid is used (Comparative Example 5) ) Was also subjected to the above performance evaluation test, and the results are also shown in Table 1.

The invention's effect As is clear from the comparison between the performance evaluation tests of the examples of Table 1 and Comparative examples 1 to 4, (II) is higher than that of the component (I) alone.
By blending the components, their high temperature characteristics are significantly improved (viscosity at high temperature increases, evaporation loss amount decreases), and the traction coefficient is also improved, which cannot be put to practical use alone (II) component It can be seen that is very effectively acting as the compounding agent of the component (I).

In addition, the compositions of Examples according to the present invention were used in Comparative Example 5, 2, 4 which are generally used as traction drive fluids.
-It is particularly excellent in high temperature characteristics as compared with dicyclohexyl-2-methylpentane and is useful as a fluid for traction drive.

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Claims (1)

[Claims] 1. A kinetic viscosity at 40 ° C., which is one or more alkylaromatic compounds selected from the group consisting of (I) (A) alkylbenzene, (B) alkylnaphthalene, and (C) diphenylalkane. Is 2-40cSt
20-80% by weight, and (II) general formula (In the formula, n represents an integer of 0 or 1, and R ₁ and R ₂ are R ₁
= H, R ₂ = CH ₃ , and R ₁ = CH ₃ R ₂ = H. ). A fluid composition for traction drive, which comprises a mixture of polycyclohexylalkane represented by the formula (1) and 80 to 20% by weight.