JPS62230895A - Fluid for improved traction - Google Patents

Abstract

PURPOSE:To provide the titled relatively inexpensive fluid giving high coefficient of traction, comprising a both cyclohexyl ring and chain hydrocarbon-bound ester compound (derivative) and hydrocarbon polymer. CONSTITUTION:The objective fluid comprising 0.1-95(pref. 10-70)wt% of (A) an ester (derivative) of formula (A' is -COO- or -OOC-; n is 1-14; R1 is H or 1-8C alkyl; R2 is H or 1-3C alkyl) plus (B) a hydrocarbon polymer (pref. polybutene) or ester polymer.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an improved traction fluid, and more specifically, it relates to an improved traction fluid containing a compound in which a cyclohexyl ring and a chain hydrocarbon are ester-bonded, or a derivative thereof, and a carbonized This invention relates to a traction fluid containing a hydrogen-based polymer or an ester-based polymer as a base oil.

(Prior Art) In automobiles or industrial machines, traction drive power transmission devices that transmit power to driven parts using traction drive mechanisms have attracted attention, and research and development have been actively promoted in recent years. A traction drive mechanism is a power transmission mechanism that uses rolling friction, etc., and because it does not use gears like conventional gears, vibration and noise are reduced, and gear changes at high speeds can be performed very smoothly. Improving the fuel efficiency of cars is an important issue in the automobile industry, but if a traction drive is applied to a car's transmission to make it continuously variable, the engine can always be operated in its highest fuel efficiency range, making it easier to replace conventional transmission systems. It is said that fuel consumption can be reduced by more than 20%. Recent research results include the development of materials with high fatigue strength and theoretical analysis of traction mechanisms, and the correlation between the molecular structure and traction coefficient of the components of traction fluids is gradually being clarified. Here, the traction coefficient is defined as the ratio of the traction force generated by sliding of the contact portions of rotating bodies that contact each other in a rolling friction power transmission device to the normal load.

Traction fluids must be lubricating oils with a high traction coefficient, and it has been confirmed that those with a naphthene ring molecular structure exhibit high performance.
As a commercially available product, Monsando's "Santo Truck ■" is widely known.

As a traction fluid having a naphthene ring, di(cyclohexyl) is disclosed in Japanese Patent Publication No. 47-35763
Alkanes or dicyclohexanes are disclosed. This patent states that the traction coefficient of a fluid containing a perhydrogenated (alpha methyl) styrene polymer, a hydrindane compound, etc., in the alkane compound is at a high level. Furthermore, JP-A-59-191
Publication No. 797 discloses a traction fluid containing an ester compound having a naphthene ring, in which an ester obtained by aromatic nuclear hydrogenation of cyclohexanedicarboxylic acid dicyclohexyl ester or phthalic acid dicyclohexyl ester is used as a traction fluid. It is preferred as such.

(Problems to be Solved by the Invention) As mentioned above, in recent years the automobile industry has been actively promoting the development of continuously variable transmissions. Fluids with as high a traxidin coefficient as possible are desired because they can increase the permissible transmission force, making it possible to downsize the entire device and reducing the amount of exhaust gases that are a problem in terms of pollution. However, the current quantity is also said to have high performance.
Even commercially available traction fluids have the problem of not providing satisfactory performance in terms of traction coefficient when used in such traction drive devices, and moreover, they are expensive. Furthermore, the traction fluid proposed in Japanese Patent Publication No. 4B-357H also has problems in terms of performance and price since it contains alpha methylstyrene polymer or a similar substance as one of its components.

(Means for Solving the Problems) As a result of extensive research in order to obtain a traction fluid that has a high traction coefficient and is relatively inexpensive, the present inventors discovered that the cyclohexyl ring has an ester bond with a chain hydrocarbon. The present invention was completed by confirming that a base oil fluid with high performance can be economically provided by blending a specific amount of a hydrocarbon polymer or an ester polymer with a compound or a derivative thereof.

In the present invention, in the general formula c, A' is an ester bond of -C00- or 10OC-, n is 1 to 14, and R1 is selected from a hydrogen atom and an alkyl group having 1 to 8 carbon atoms. At the atom or group, R
2 is the same or different atom or group selected from a hydrogen atom and an alkyl group having 1 to 3 carbon atoms. This relates to a traction fluid characterized in that it contains 96 to 95% by weight.

A first object of the present invention is to provide a high performance traction fluid having a high traction coefficient. A second object of the present invention is to provide a traction fluid that is economical, readily available, and easy to apply to equipment.

The traction fluid of the present invention is composed of a two-component base oil, in which an ester or its derivative as an A component is blended with a specific amount of a hydrocarbon polymer or an ester polymer as a B component.

Component A of the present invention is a compound having an ester bond between a cyclohexyl ring and a chain hydrocarbon, or a derivative thereof, and has the above structural formula. A' of the ester bond is -C
It is OO- or 1000-, and the number n of carbon atoms in the chain hydrocarbon skeleton is from 1 to I4, preferably from 2 to 10. When n is 0, the traction coefficient is low, and when n is 15 or more, the viscosity becomes high, which is not preferable. This ester or its derivative is produced by the following method and has a viscosity of 3 to 1 at 40°C.
50C5T, particularly preferably 4-120C3T 100°C
It has a viscosity of 1 to 20 CST, particularly preferably 1 to 16 C3T. Further, examples of ester derivatives include amino compounds, phenolic compounds, and ether compounds.

Component A can be produced by any of the following methods. The first method is a method using an esterification reaction between a -hydric alcohol compound and a cyclohexanecarboxylic acid compound. - As the alcohol compound, one whose main chain has 1 to 14 carbon atoms is selected, especially one whose main chain has 2 to 14 carbon atoms.
Monohydric alcohols having a molecular weight of 10 are preferred. Specifically, ethanol, propatool, 2-propatool, butanol, 2-methyl-2-propatool, 3.3.5-trimethyl-■-hexanol, LLL5-tetramethyl-1
-Hexanol and the like. The cyclohexanecarboxylic acid compound includes, in addition to cyclohexanecarboxylic acid, an alkyl group having 1 to 8 carbon atoms, such as methylcyclohexanecarboxylic acid or ethylcyclohexanecarboxylic acid.

Particularly preferred is cyclohexanecarboxylic acid.

The esterification reaction is carried out under conditions of excess alcohol or excess acid. When excessive acid conditions are employed, the acid is reacted in an amount of 1 to 2 times the mole (particularly preferably 1.2 to 1.8 times) per mole of the -hydric alcohol compound. The reaction temperature is 150
The temperature is ~250°C, preferably 170-230°C, and the reaction time is 10-40 hours, preferably 15-25 hours. The reaction pressure may be increased or reduced pressure, but normal pressure is preferred from the viewpoint of reaction operation. Under this condition, excess acid acts as a catalyst. Further, an appropriate amount of alkylbenzene such as xylene or toluene can be added as a solvent. By adding a solvent, the reaction temperature can be easily controlled.

As the reaction progresses, the water produced evaporates,
The reaction is terminated when the water becomes equal in mole to the alcohol. Excess acid is neutralized with an aqueous alkaline solution and removed by washing with water. When using an acid that is difficult to remove by alkaline washing, the acid is made equal in mole to the alcohol and reacted using a catalyst. As a catalyst, phosphoric acid, para-toluenesulfonic acid.

Although sulfuric acid and the like can be used, it is most preferable to use phosphoric acid in terms of increasing the reaction rate and the yield of ester. The ester compound of the present invention is obtained by finally distilling the reaction product under reduced pressure to remove water and the solvent.

When using excess alcohol conditions, 1 to 2 moles of alcohol (particularly preferably 1.2 to 1.8 moles) is reacted with 1 mole of the cyclohexanecarboxylic acid compound. The reaction temperature is 150-250°C, preferably 170-250°C.
The temperature is 230°C, and the reaction time is 10 to 40 hours, preferably 15 to 25 hours. The reaction pressure may be increased or reduced pressure, but normal pressure is preferred from the viewpoint of reaction operation. Under this condition, excess acid acts as a catalyst. Further, an appropriate amount of alkylbenzene such as xylene or toluene can be added as a solvent.

By adding a solvent, the reaction temperature can be easily controlled. As the reaction progresses, the water produced evaporates, and the water becomes equimolar to the acid. As a catalyst, phosphoric acid, para-toluenesulfonic acid, sulfuric acid, etc. can be used, but phosphoric acid is most preferably used in terms of increasing the reaction rate and increasing the yield of ester. After the reaction is completed, the product is neutralized with an aqueous alkaline solution and washed with water to remove unreacted acid and catalyst. The ester compound of the present invention can be obtained by distilling the reaction product under reduced pressure to remove water, solvent, and excess alcohol.

A second method for producing component A of the present invention is a method by esterifying a cyclohexanol compound and a carboxylic acid whose main chain has 2 to 15 carbon atoms. In addition to cyclohexanol, the cyclohexanol compound includes compounds having an alkyl group having 1 to 8 carbon atoms, such as methylcyclohexanol, ethylcyclohexanol, tert-butylcyclohexanol, and the like. Particularly preferred is cyclohexanol. The carboxylic acid has a main chain of 2 to 15 carbon atoms, preferably a main chain of 3 to 11 carbon atoms.

Examples include acetic acid, propionic acid, butyric acid, lauric acid, trimethylhexanoic acid, tetramethylhexanoic acid, and the like. The esterification reaction is carried out under excess acid conditions or under excess alkali conditions. When using excess acid conditions, add 1 acid to 1 mole of cyclohexanol compound.
~2 times the mole (particularly preferably 1.2 to 1.8 times the mole) is reacted. The reaction temperature is 150-250°C, preferably 1
The temperature is 70 to 230°C, and the reaction time is 10 to 40 hours, preferably 15 to 25 hours. The reaction pressure may be increased or reduced pressure, but normal pressure is preferred from the viewpoint of reaction operation. As the catalyst, phosphoric acid, para-toluenesulfonic acid, sulfuric acid, etc. can be used, but it is most preferable to use phosphoric acid in terms of increasing the reaction rate and increasing the yield of ester. An appropriate amount of alkylbenzene such as xylene or toluene can be added as a solvent. By adding a solvent, the reaction temperature can be easily controlled. As the reaction progresses, the produced water evaporates, but the reaction is terminated when the water becomes equimolar to the alcohol. The catalyst and excess acid are neutralized with an aqueous zeta alkali solution and removed by washing with water. The ester compound of the present invention is obtained by finally distilling the reaction product under reduced pressure to remove water and the solvent.

When using excess alcohol conditions, the cyclohexanol compound is reacted with the carboxylic acid in an amount of 1 to 2 times the mole (especially preferably 1.2 to 1.8 times the mole). The reaction temperature is 150-250°C, preferably 170-230°C,
The reaction time is 10 to 40 hours, preferably 15 to 25 hours. The reaction pressure may be increased or reduced pressure, but normal pressure is preferred from the viewpoint of reaction operation. Further, an appropriate amount of alkylbenzene such as xylene or toluene can be added as a solvent. By adding a solvent, the reaction temperature can be easily controlled. As the reaction progresses, the produced water evaporates, but the reaction is terminated when this water reaches equal moles of the carboxylic acid. Phosphoric acid, p-toluenesulfonic acid, sulfuric acid, etc. are used as a catalyst. Phosphoric acid is most preferably used since it increases the reaction rate and yield of ester. After the reaction, the catalyst and alkaline ester compound can be obtained by finally distilling the reaction product under reduced pressure to remove water, solvent, and excess alcohol.

The hydrocarbon polymer as component B is polyolefin,
These include hydrocarbon polymer compounds having a naphthene ring or alkylstyrene polymers, while ester polymers are polymers of ester compounds having an alkyl side chain and/or a cyclohexyl ring. Examples of polyolefins include polyalphaolefins, olefin copolymers, polymers whose unsaturated bonds are saturated with hydrogen, and polymers obtained by modifying these polymers using small amounts of modifiers. . Note that examples of the modifier include alkyl carboxylic acids, alcohols, amines, and the like. Among these, particularly preferred are polyalphaolefins.

Preferred polyalphaolefins as component B are those having quaternary carbon atoms or tertiary carbon atoms in the main chain, and are polymers of alpha olefins having 3 to 5 carbon atoms and hydrogenated products thereof. For example, polypropylene, polybutene, polyisobutylene.

Among polybenthenes and hydrogenated products thereof, particularly preferred are polybutene, polyisobutylene, and hydrogenated products thereof. Polyisobutylene can be represented by the following structural formula.

Moreover, the hydrogenated product is shown by the following structural formula.

However, the above degree of polymerization n is 6 to 200.

Commercially available products may be used for polybutene and polyisobutylene, but they can also be produced by known polymerization methods. Also,
The hydrogenated product is produced by reacting polyisobutylene or the like in the presence of hydrogen. Particularly preferred polyalphaolefins have molecular weights in the range of 500 to 10.000, more preferably 900 to 5.000. (The molecular weight range of 100 is used. The molecular weight can be adjusted by decomposing a high molecular weight polyalphaolefin, mixing polyalphaolefins with different molecular weights, etc. Olefin copolymer (OCP) is an ethylene , propylene, butylene,
It is obtained by polymerizing two or more olefins selected from pentene, styrene, etc. OCP has a structure in which olefins are irregularly connected to each other, and does not have a regular germ-dialkyl type structure like polyalphaolefins such as polybutene.

The ester polymer as component B is (R is a hydrocarbon group having 1 to 18 carbon atoms, n is 100 to s,
ooo or its derivatives), (R is a hydrocarbon group having 1 to 18 carbon atoms, n is 100 to 5
．． 000 or a derivative thereof). A preferred ester polymer has a cyclohexyl ring in which R is 6 to 12 and n is 200 to 250.
polycyclohexyl acrylate or polycyclohexyl methacrylate.

Component A in the present invention, for example, an ester of 3.5.5-trimethylhexanoic acid and cyclohexanol exhibits a traxidin coefficient of 0.080 to 0.090,
Component B, for example polybutene, has a traction coefficient of 0.
It shows a value of 075 to 0.085.

Both the A component and the B component of the present invention have lower traction coefficients than commercially available traction fluids, so even if the A component or the B component is applied alone to a traction drive device, high performance cannot be achieved. however,
Add 0.1 to 95% by weight of the hydrocarbon polymer or ester polymer of component B to the ester of component A, especially 10 to 7% by weight.
By blending 0% by weight, a preferred traction fluid can be obtained. That is, the hydrocarbon such as the alkyl group of component B exerts a synergistic effect (traction coefficient improvement effect) with the cyclohexyl ring of component A, and
The components are cheap and have excellent viscosity characteristics, so by blending 0.1 to 95% by weight of component B to component A, it is possible to increase the traction coefficient and obtain an economical traction fluid. be.

The traction fluid of the present invention can also contain various additives depending on the intended use. That is, if the traction device is to be subjected to two large loads at high temperatures, about 0.01 to 5% by weight of one or more additives such as antioxidants, antiwear agents, and antirust agents can be blended.

In the present invention, the traction fluid refers to a fluid used in a device that transmits rotational torque through point contact or line contact, or a transmission device having a similar structure. The Traxidin fluid of the present invention has a higher traction coefficient than conventionally known fluids, and has a traction coefficient higher than that of conventional products depending on properties such as viscosity.
It has a 10% higher traction coefficient. Therefore, the traction fluid of the present invention is suitable for use in internal combustion engines such as small passenger cars, relatively low power transmission devices such as spinning machines and food manufacturing machines, as well as traction drive devices such as large power industrial machines. can also be preferably applied.

(Function) The traction fluid of the present invention has a much superior traction coefficient compared to known fluids, but it is still not completely clear why it can exhibit such a high traction coefficient. Not explained.

Basically, it is thought that this is based on the unique molecular structure of the traction fluid of the present invention.

First, component A of the traction fluid of the present invention is an ester having a cyclohexyl ring in the compound molecule, and due to the ester bond, a dipole opening force acts between the molecules. It is believed that this dipole opening force changes the fluid into a stable glass state under high load conditions of the traction device, increasing the anti-shear force. Furthermore, the B component of the traction fluid of the present invention has a hydrocarbon such as an alkyl group. Therefore, it is thought that when the traction device is under high load, the cyclohexyl ring of component A and the alkyl group of component B are tightly engaged like gears, and when the load is released, they quickly separate and become fluidized.

(Example) Examples 1 to 18 Ester AI of the present invention was synthesized by the following method. First, add 150.2 g of cyclohexanol and 3.5 g of cyclohexanol to a reaction vessel.
．． 5-trimethylhexanoic acid 158. H (molar ratio of alcohol to acid -1.5:1) was collected, and 1% by weight of phosphoric acid was added to the total amount. Next, the reaction vessel was heated to 180°C, and the reaction was carried out in a temperature range of 170°C to 200°C under normal pressure. Heating was terminated when the amount of water produced during the reaction reached the same mole as the amount of the acid.

A pure ester that does not undergo vacuum distillation after alkali washing to remove unreacted substances from the mixture of the reaction product cyclohexanol and trimethylhexanoic acid, the unreacted cyclohexanol, and the phosphoric acid catalyst. 81 was isolated.

In the same manner, other esters A and A3 of the present invention were synthesized using the following raw materials.

A2...3.5.5-trimethyl-1-hexanol and cyclohexanecarboxylic acid (excess acid and no catalyst used) A3...Lauric acid and cyclohexanol (using phosphoric acid catalyst) Next, the ester produced in this way The average molecular weight is 900~
Bolybdenum B1 of 2350 and olefin copolymerization were blended to give a traction coefficient of 71-1. The allll characteristics of the traction coefficient are as follows.

This copolymer of ethylene and propylene has an average molecular weight of 323,000 1 This polycyclohexyl acrylate has an average molecular weight of 50,000 Measuring equipment, Soda type 40-ra traction tester Test conditions Niura temperature 20'C, 07 in degrees 3 G'' C average Hertzian pressure 1,2 GPa.

Rolling speed 3.8m/s.

Slip rate: 3.0% As shown in Table 1, the traction fluid of the present invention was found to have significantly superior traction performance compared to conventional traction fluids.

Comparative Examples 1 to 5 Traction coefficients were measured under the conditions shown in Examples using traction fluids prepared solely from components A1 to A3 and component B1, and a commercially available traction fluid (Santotrack ■).

As shown in Table 1, it was found that the traction coefficients of all the fluids were 1 to 10% smaller than the traction fluid of the present invention.

(Effects of the Invention) The present invention provides a traction fluid in which a specific amount of a hydrocarbon or an ester polymer (component B) is blended into a compound in which a cyclohexyl ring and a chain hydrocarbon are ester bonded (component A). Not only does it have an extremely high traction coefficient, it is also inexpensive and has excellent viscosity characteristics.

Therefore, when used in a power transmission device, particularly a traction drive device, the shearing force under high loads can be dramatically increased, so that the device can be miniaturized and economically supplied.

Claims (1)

[Claims] 1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, A' is an ester bond of -COO- or -OOC-, n is 1 to 14, R_1 is a hydrogen atom and Carbon number 1
to 8 alkyl groups, R_2 is the same or different atom or group selected from a hydrogen atom and an alkyl group having 1 to 3 carbon atoms] or a derivative thereof, carbonized. An improved traction fluid characterized by containing 0.1 to 95% by weight of a hydrogen polymer or an ester polymer. 2) The fluid according to claim 1, wherein the hydrocarbon polymer is a polyolefin. 3) The fluid according to claim 1, wherein the amount of the hydrocarbon polymer or ester polymer is 10 to 70% by weight. 4) The fluid according to claim 1 or 2, wherein the hydrocarbon polymer is polybutene. 5) The fluid according to claim 1, wherein R_1 of the ester is selected from a hydrogen atom and an alkyl group having 1 to 4 carbon atoms. 6) The fluid according to any one of claims 1 to 4, wherein the hydrocarbon polymer or ester polymer has an average molecular weight of 500 to 10,000. 7) Claim 1 in which n of the ester is 2 to 10
or the fluid described in paragraph 5. 8) The fluid according to claim 1, 5, or 7, wherein R_2 of the ester is either a hydrogen atom or a methyl group.