JPH06240274A - Lubricant composition for ball joint - Google Patents

Abstract

PURPOSE:To obtain a lubricant composition for ball joint chiefly used in e.g. an automotive suspension or steering and having a low initial operation torque and having a property of suppressing fluttering during high-speed running. CONSTITUTION:The composition is prepared by mixing a base oil or a wax with at least 50wt.% fatty acid salt obtained by effecting the addition reaction of an amidoamine compound obtained by reacting a vegetable oil with tetraethylenepentamine with a polymerized fatty acid obtained by condensing tall oil fatty acid or tallow oleic acid and oleic acid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricant composition for a ball joint, which is mainly used in a suspension or a steering of an automobile, and is composed of a metal ball stud and a synthetic resin ball seat.

[0002]

2. Description of the Related Art As a lubricant for ball joints, Japanese Patent Publication No. 62-54155, in which a diamide compound is blended with Duomin T-dioleoate as a base oil, polyethylene wax, paraffin wax and micro wax using a urea compound as a thickener. There is a lubricant for ball joints described in Japanese Patent Application Laid-Open No. 2-194095, which contains a crystallin wax and a fatty acid amide wax.

[0003]

As automobiles become higher in quality and higher in performance, the performance required for each component is becoming more severe. Similarly, ball joints are required to have high functionality. The main function of the ball joint is to enable the vertical movement and steering movement of the tire, have a swing angle that follows the vertical movement of the tire, and operate without adversely affecting the steering movement or feeling. Torque, no rattling that causes shimmy or abnormal noise, withstanding use environment such as mud, water, low temperature, high temperature, having sufficient strength and durability against input from tires, etc. Is required. Especially in recent years, the lubricant that suppresses the smooth steering performance of the steering wheel and the flutter phenomenon that occurs when driving at high speed (when the unbalance of the tire is input and the natural frequency of the control system matches the vibration of the steering wheel due to resonance phenomenon) Are becoming required.

[0004]

[Means for Solving the Problems] Like the flutter phenomenon,
It is known that vibration can be suppressed in the steering system by always applying a frictional force to the steering system, but there is a problem that the operation becomes heavy and the operation feeling is deteriorated. In order to solve these problems, in Japanese Utility Model Publication No. 62-15537, a cross section orthogonal to the ball stud axial direction and a spherical concave portion of the ball seat corresponding thereto are each formed into an elliptical shape, and the long axis of the ball in a straight traveling state of the vehicle. And a ball joint of a vehicle configured to match the minor axis of the spherical concave portion, in Japanese Utility Model Publication No. 63-22331, a cylindrical case having openings formed at both ends, and a case housed in the case. A resin bearing having elasticity and having a substantially spherical inner hole communicating with one opening of the case, and a spherical member inserted from the one opening and rotatably supported in the inner hole of the resin bearing. An arm having a ball stud, a disk-shaped cap that closes the other opening of the case, and an interposing member between the cap and the resin bearing. An elastic plate having elasticity for pressing the resin bearing against the spherical portion is provided, and the peripheral portions of the cap and the elastic plate are overlapped with each other and are locked in a concave groove formed in the inner peripheral surface of the case. There are ball joints, etc. characterized by that, but none of them are sufficient.

Further, it is possible to suppress an increase in the lift amount after long-term use and to suppress the flutter phenomenon to some extent by increasing the preload at the time of assembling the ball joint. However, by increasing the preload, the initial operating torque is increased. And the smooth steering performance of the steering wheel is impaired.

The present inventors reduced the initial operating torque of the ball joint in the lubricant for ball joints,
As a result of intensive research to develop a lubricant having a characteristic (frequency characteristic) that suppresses the flutter phenomenon during high-speed running, an amidoamine obtained by the reaction of vegetable oil and tetraethylenepentamine in a base oil or wax. It was found that a lubricant using a fatty acid salt obtained by adding a oleic acid and a polymerized fatty acid obtained by a condensation reaction of tall oil fatty acid or tallow oleic acid to a compound has frequency characteristics, and completes the present invention. Came to.

That is, the present invention relates to a base oil or wax, a polymerized fatty acid and an olein obtained by a condensation reaction of a tall oil fatty acid or tallow oleic acid with an amidoamine compound obtained by the reaction of vegetable oil and tetraethylenepentamine. The present invention relates to a lubricant composition for ball joints, which contains 50% by weight or more of a fatty acid salt obtained by adding an acid.

[0008]

The lubricant composition for ball joints of the present invention is characterized in that the amidoamine compound obtained by the reaction of vegetable oil and tetraethylenepentamine is polymerized fatty acid obtained by the condensation reaction of tall oil fatty acid or tallow oleic acid. And a fatty acid salt obtained by adding oleic acid. Amidoamine compounds obtained by the reaction of vegetable oil and tetraethylenepentamine are widely used as curing agents for epoxy resins, and are well known to have highly reactive primary and secondary amino groups in the molecule. It is a compound. Polymerized fatty acids obtained by the condensation reaction of tall oil fatty acids or beef tallow oleic acid are also known compounds used as raw materials for polyamides, polyesters, polyurethanes, epoxy resins and the like.

However, it has not been found that a fatty acid salt obtained by adding a polymerized fatty acid and oleic acid to an amidoamine compound has excellent frequency characteristics, and the present invention uses such a fatty acid salt as a base oil or This is achieved by blending with waxes.

When the lubricant composition for a ball joint of the present invention is applied between the metal ball stud of the ball joint and the synthetic resin ball seat, an extremely thick and strong lubricating film is formed and the lubricating characteristics are maintained. The fatty acid salt obtained by adding a polymerized fatty acid and oleic acid to an amidoamine compound has a high polarity, can obtain extremely good wettability for lubricating a metal and a synthetic resin, and can also obtain excellent lubricating properties. Therefore, it is considered that the effect of suppressing the flutter phenomenon during high-speed traveling can be obtained at the same time as reducing the initial operating torque.

In the present invention, a lubricating oil such as a mineral oil, an ester synthetic oil, an ether synthetic oil, a hydrocarbon synthetic oil or a mixed oil thereof can be used as a base oil. The waxes that can be used include natural wax, various mineral oil-based or synthetic waxes, such as montan wax, carnauba wax, amide compound of higher fatty acid, paraffin wax, microcrystalline wax, polyolefin wax, ester wax, etc. Can be given.
The lubricant composition for a ball joint according to the present invention is used by being incorporated into a ball joint, and therefore waxes are used in order to avoid leakage, but if the content exceeds 50% by weight of the constituents, it is lubricated. It becomes too hard as an agent and the initial operating torque increases, which is not suitable for the present invention.

The lubricant composition for ball joints according to the present invention may contain an antioxidant, a rust preventive and the like, if necessary, to improve the performance of the lubricant composition.

[0013]

EXAMPLES The present invention will be specifically described below with reference to Examples, Comparative Examples and Test Examples. Example 1 Amidoamine compound (amine value 450, viscosity 190 to 3
90 mPa · S), 22.8 g of polymerized fatty acid and 30.8 g of oleic acid were mixed at room temperature, and 25.0 g of ethylenebisstearoamide was added to the obtained adduct and dissolved. After cooling to room temperature, the mixture was kneaded with a three-stage roll mill to obtain a desired lubricant composition.

Example 2 Amidoamine compound (amine value 450, viscosity 190 to 3
90 mPa · S) (22.8 g), polymerized fatty acid (21.0 g) and oleic acid (31.2 g) were mixed at room temperature, and ethylenebisstearoamide (25.0 g) was added to the obtained adduct and dissolved. After cooling to room temperature, the mixture was kneaded with a three-stage roll mill to obtain a desired lubricant composition.

Example 3 Amidoamine compound (amine value 450, viscosity 190 to 3
90 mPa · S) (27.4 g), polymerized fatty acid (37.7 g) and oleic acid (24.9 g) were mixed at room temperature, and 10.0 g of ethylenebisoleylamide was added to the obtained adduct and dissolved. After cooling to room temperature, the mixture was kneaded with a three-stage roll mill to obtain a desired lubricant composition.

Example 4 Amidoamine compound (amine value 450, viscosity 190 to 3
90 mPa · S) (15.2 g), polymerized fatty acid (20.9 g) and oleic acid (13.9 g) were mixed at room temperature, and ethylenebisstearoamide (50.0 g) was added to the obtained adduct and dissolved. After cooling to room temperature, the mixture was kneaded with a three-stage roll mill to obtain a desired lubricant composition.

Example 5 Amidoamine compound (amine value 450, viscosity 190 to 3
90 mPa · S) 22.8 g, polymerized fatty acid 31.4 g and oleic acid 20.8 g are mixed at room temperature, and the resulting adduct is paraffin mineral oil (kinematic viscosity 40 ° C. 100 mm
^{2 / s) (} 25.0 g) was added and mixed by heating, and after cooling to room temperature, a target lubricant composition was obtained.

Comparative Example 1 Amidoamine compound (amine value 450, viscosity 190 to 3
90 mPa · S) (27.7 g) and oleic acid (62.3 g) were mixed at room temperature, and 10.0 g of ethylenebisoleylamide was added to the obtained adduct and dissolved by heating. After cooling to room temperature, the mixture was kneaded with a three-stage roll mill to obtain a desired lubricant composition.

Comparative Example 2 Polyamide amine compound (amine value 390, viscosity 2.5)
~ 4.0 Pa · S) 24.8 g and oleic acid 50.2 g
Were mixed at room temperature, and 25.0 g of ethylenebisstearoamide was added to the obtained adduct and dissolved by heating. After cooling to room temperature, the mixture was kneaded with a three-stage roll mill to obtain a desired lubricant composition.

Comparative Example 3 Amidoamine compound (amine value 450, viscosity 190 to 3
90 mPa · S) (30.1 g) and polymerized fatty acid (69.9 g) were mixed at room temperature to obtain an adduct, but the adduct was resinified and solidified, so that it could not be used as a lubricant.

Comparative Example 4 Amidoamine compound (amine value 450, viscosity 190 to 3
90 mPa · S) (12.2 g), polymerized fatty acid (16.8 g) and oleic acid (11.0 g) were mixed at room temperature, and 60.0 g of ethylenebisstearoamide was added to the obtained adduct and dissolved. After cooling to room temperature, the mixture was kneaded with a three-stage roll mill to obtain a desired lubricant composition.

Comparative Example 5 Amidoamine compound (amine value 450, viscosity 190 to 3
90 mPa · S) 12.2 g, polymerized fatty acid 16.8 g and oleic acid 11.0 g are mixed at room temperature, and the resulting adduct is paraffinic mineral oil (kinematic viscosity 40 ° C. 100 mm
^{2 / s) (} 60.0 g) was added and mixed by heating, and after cooling to room temperature, a target lubricant composition was obtained.

Comparative Example 6 A commercially available lithium grease which uses lithium stearate as a thickener and mineral oil as a base oil.

Test Example Next, a ball joint made up of a steel ball stud 1 and a polyacetal resin sheet 2 shown in FIG. 1 was applied to the above Examples 1 to 5 and Comparative Examples 1, 2, 4, and 4.
Each of the lubricant compositions 3 of Nos. 5 and 6 was enclosed, and the following performance test was performed. The results obtained are shown in Table 1.

Ball joint frequency characteristic test The measuring method is as follows: Each lubricant composition is enclosed in the steel ball stud part of the ball joint and the resin sheet, and the upper part of the steel ball stud is rotated at a specified rotation angle from low speed to high speed. The frequency was changed and vibration was performed, and the torque generated at that time was measured. As a result, in addition to evaluating the torque at startup (at low speed) as the initial torque, the frequency and the rotation angle were converted into angular velocities, and the generated torque was arranged as the rotation torque.

As shown in Table 1 and FIG. 2, the test results are shown in Examples 1, 2 and 3 according to the present invention with respect to the increase of the angular velocity.
Although an increase in the rotational torque (frequency characteristic) is remarkably recognized, in Comparative Examples 1 and 6, almost no change is recognized, and in Comparative Example 2, the amount of change is small and a sufficient effect is not recognized.

It has been found that, by using the lubricant composition of the present invention, in the ball joint, the frictional resistance is low in the low speed range, and the frictional resistance increases in the high speed range. Also, the effect was confirmed in an actual vehicle test using a ball joint enclosing the lubricant composition of the present invention, and the vibration of the steering wheel was suppressed when traveling at 100 km / hour.

[0028]

[Table 1]

[0029]

As described above, according to the present invention, a base oil or wax can be obtained by a condensation reaction of tall oil fatty acid or tallow oleic acid with an amidoamine compound obtained by the reaction of vegetable oil and tetraethylenepentamine. The fatty acid salt obtained by adding the polymerized fatty acid and oleic acid to
By using a lubricant composition for a ball joint characterized by containing 0% by weight or more, the effect that the initial operating torque is low and that the flutter phenomenon during high speed running is suppressed (frequency characteristic) was gotten.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a representative ball joint.

FIG. 2 shows a lubricant composition of the present invention and a comparative example (including commercial products).
FIG. 4 is a diagram showing the relationship (frequency characteristic) between the angular velocity and the rotational torque of FIG.

[Explanation of symbols]

 1 ball stud 2 resin sheet 3 lubricant composition

Continuation of the front page (51) Int.Cl. ⁵ Identification code Reference number within the agency FI Technical indication C10N 30:02 40:04 40:06 (72) Inventor Kazumasa Kinoshita 10 Hamadashita, Nakahata-cho, Nishio-shi, Aichi Shares Company Otics (72) Inventor Tetsuo Kondo 10 Hamadashita, Nakahata-cho, Nishio-shi, Aichi Stock Company Otics (72) Inventor Yasushi Hatakeyama 1-4-1, Tsujido-jindai, Fujisawa, Kanagawa Kyodo Yushi Co., Ltd. ( 72) Inventor Yasushi Yaegashi 1-4-1 Tsujido-Kandai, Fujisawa City, Kanagawa Prefecture Kyodo Yushi Co., Ltd.

Claims (1)

[Claims] 1. Addition of polymerized fatty acid and oleic acid obtained by condensation reaction of tall oil fatty acid or tallow oleic acid to amidoamine compound obtained by reaction of vegetable oil and tetraethylenepentamine to base oil or wax. A lubricant composition for a ball joint, containing 50% by weight or more of the fatty acid salt obtained by the above.