KR20190090207A - Rubber composition of self-lubricating for bush - Google Patents

Abstract

The present invention relates to a self-lubricating rubber composition for bushing. More specifically, the present invention relates to the self-lubricating rubber composition for bushing having excellent durability and vibration insulation performance by reducing friction and frictional coefficients. According to the present invention, it is possible to manufacture the self-lubricating rubber composition having reduced friction and friction coefficients by using oleamide as a slip agent. In addition, according to the present invention, there is an effect of providing a rubber composition that satisfies rubber materials MS and ES since frictional force and friction coefficients are reduced. Furthermore, according to the present invention, it is possible to manufacture the rubber composition having excellent durability and vibration insulation performance by using oleamide as the slip agent.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a rubber composition for self-

The present invention relates to a self-lubricating rubber composition for bushing, and more particularly, to a self-lubricating rubber composition for bushing having reduced frictional force and friction coefficient and excellent durability and vibration insulation performance.

In general, the rubber composition is used for automobile industrial parts, industrial rubber products, electrical insulating materials, civil engineering materials, rubber products such as rubber-coated foams, polypropylene and the like. Various rubber compositions are used in various compositions according to their applications. Rubber compositions are widely used in various assembling parts including automobile tires.

An automotive dustproof rubber is a rubber used for vibration prevention. It is used to prevent vibration from a motor or an engine from being transmitted to the outside by using a property that rubber absorbs kinetic energy. Various physical properties of anti-vibration rubber have been improved according to the development of the rubber industry, and adhesion to other parts such as metal has been facilitated and widely used in various businesses such as machine tools, measuring machines and automobiles.

Particularly, when assembling a suspension system of an automobile, a vibration-proof rubber for absorbing vibration transmitted to the vehicle body is used, and when the automobile passes over the uneven portion, abrasion occurs due to the specific adhesiveness of the rubber. Causing the driver to feel a sense of riding, which in turn affects the quality of the automobile, resulting in dissatisfaction of the users.

As a method for solving these problems, Micro wax, Erucamide and the like are conventionally used as a slip agent to be blended in rubber, but it is not commercialized because of persistence, appearance deficiency, cost problems, and the above materials have a low coefficient of friction and a low friction There is a problem that a good effect can not be exhibited on the side and the merchantability is lowered.

An object of the present invention is to provide a self-lubricating rubber composition for bushing having reduced frictional force and friction coefficient by using oleamide as a slip agent.

However, the technical problem to be solved by the present invention is not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, 1 to 5 parts by weight of an oleamide slip, 1.8 to 2.4 parts by weight of an heat-resistant promoter, and 55 to 60 parts by weight of carbon black may be contained in 100 parts by weight of natural rubber.

The heat-resistant promoter may be any one of Tetramethy1-thiuram disulfide or Tetrabutyl thiuram disulfide.

The carbon black may be either HAF (High abrasion furnace) or FEF (Fast extruding furnace).

The rubber composition may further comprise 5 to 10 parts by weight of zinc oxide, 6.0 to 10.0 parts by weight of a plasticizer, 4.5 to 6.1 parts by weight of an antistatic agent and 1.5 to 2.4 parts by weight of sulfur.

The plasticizer may be a paraffin plasticizer.

The amine inhibitor may be an amine nitrogen inhibitor.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to produce a self-lubricating rubber composition for bushing with reduced frictional force and friction coefficient by using oleamide as a slip agent.

Further, according to the present invention, it is possible to provide a rubber composition which satisfies the rubber materials MS and ES by reducing the frictional force and the friction coefficient.

Further, according to the present invention, a rubber composition having excellent durability and vibration insulation performance can be produced by using oleamide as a slip agent.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the results of evaluation of friction coefficient of a rubber composition according to an embodiment of the present invention. FIG.
2 is a graph showing the results of a friction force evaluation test of a rubber composition according to an embodiment of the present invention.
3 is a graph showing the results of an experiment for evaluating tensile strength of a rubber composition according to an embodiment of the present invention.
4 is a graph showing the experimental results of the elongation percentage of the rubber composition according to an embodiment of the present invention.

The details of other embodiments are included in the detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments described below, but may be embodied in various forms. In the following description, it is assumed that a part is connected to another part, But also includes a case in which other media are connected to each other in the middle. In the drawings, the parts not relating to the present invention are omitted for clarifying the description of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

The present invention relates to a self-lubricating rubber composition for bushing, and more particularly, to a self-lubricating rubber composition for bushing having reduced frictional force and friction coefficient and excellent durability and vibration insulation performance.

The self-lubricating rubber composition for bush according to one embodiment of the present invention may contain 1 to 5 parts by weight of oleamide slip, 1.8 to 2.4 parts by weight of heat resistance promoter, 55 to 60 parts by weight of carbon black, .

The oleamide slipping agent is preferably contained in an amount of 1 to 5 parts by weight. When the oleamide slip agent is less than 1, the improvement rate of the frictional force and the friction coefficient is remarkably lowered and the quality of the rubber composition is deteriorated. When the oleamide slip agent exceeds 5, the addition amount of the oleamide slip agent There is a problem that the rate of increase in the effect of improving the frictional force and the frictional coefficient decreases and the efficiency decreases.

The heat-resistant promoter preferably includes 1.8 to 2.4 parts by weight, and may be one of Tetramethy1-thiuram disulfide or Tetrabutyl thiuram disulfide.

The carbon black preferably includes 55 to 60 parts by weight, and may be any one of HAF (High abrasion furnace) and FEF (Fast extruding furnace). When the content of the carbon black is less than 55 parts by weight, the reinforcing performance by the carbon black may be deteriorated. When the content of the carbon black is more than 60 parts by weight, the workability of the rubber composition may be deteriorated I do not.

The rubber composition may further comprise 5 to 10 parts by weight of zinc oxide, 6.0 to 10.0 parts by weight of a plasticizer, 4.5 to 6.1 parts by weight of a coloring agent, and 1.5 to 2.4 parts by weight of sulfur. Further, it is preferable to use a paraffin-based plasticizer as the plasticizer, and it is preferable to use an amine-based plasticizer as the weathering agent.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited by the following examples.

( Example  1) Evaluation of friction coefficient and frictional force of rubber composition

In Example 1, the friction coefficient and the frictional force of the self-lubricating rubber composition for bush according to the embodiment of the present invention were tested as follows. The rubber compositions of T1 to T6 used in the experiment in Example 1 were prepared by adding the amounts of the remaining materials as shown in Table 1, except that the oleic acid content was changed as shown in Tables 2 and 3 below.

ingredient Content (parts by weight) T1 T2 T3 T4 T5 T6 Natural rubber (SMR CV60) 100 100 100 100 100 100 Carbon black (HAF) 52 55 55 55 55 55 Zinc oxide (ZnO KS # 2) 5 5 5 5 5 5 Plasticizer (paraffin type) 8 5 5 5 5 5 Noise control (amine system) 4.5 5.6 5.6 5.6 5.6 5.6 Oleic Acid 0 One 2 3 4 5 Sulfur 2 1.5 1.5 1.5 1.5 1.5 Heat-resistance promoter (Ti-Ram) 1.5 2.2 2.2 2.2 2.2 2.2 1) Low Arm G BUSH products
2) X-MBR BUSH products
3) Assis Arm BUSH products

The friction coefficient and the frictional force were evaluated using the rubber composition prepared as shown in Table 1, and the results are shown in Tables 2 and 3 and Figs. 1 and 2, respectively. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the results of evaluation of friction coefficient of a rubber composition according to an embodiment of the present invention. FIG. 2 is a graph showing the results of an evaluation test of frictional force of a rubber composition according to an embodiment of the present invention. Friction Coefficient and Friction Rate The olefin content of T1 to T6 was sequentially added from 0PHR to 5PHR as shown in Tables 2 and 3 below, and the change in frictional coefficient and frictional force was expressed as improvement ratio.

The weight of the weight is 200g, the measuring speed is 100mm / min, the measuring scale is 100mm, and the number of reciprocations is 2 times, the force is 19.6N.

division The amount of oleic acid (PHR) Coefficient of friction Improvement rate (%) T1 0 1.3 0% T2 One 0.5 -63% T3 2 0.4 -69% T4 3 0.3 -75% T5 4 0.3 -77% T6 5 0.3 -78%

division The amount of oleic acid (PHR) Friction (kgf) Improvement rate (%) T1 0 258.0 0% T2 One 95.1 -63% T3 2 85.5 -67% T4 3 63.4 -75% T5 4 60.9 -76% T6 5 60.4 -77%

As shown in Tables 2 and 3 and FIGS. 1 and 2, it was confirmed that even when oleic acid was added in an amount of about PHR 1 at T2, the frictional coefficient and frictional force were drastically reduced as compared with T1, which did not contain oleic acid. Also, it was confirmed that the addition of oleic acid from T3 shows a tendency that the friction coefficient and the frictional force continuously decrease to a certain level, and the improvement rate also shows a tendency to decrease with the addition of oleic acid.

( Example  2) Experimental evaluation of material properties of rubber composition

Example 2 was conducted to evaluate the material properties of the self-lubricating rubber composition for bush according to the example of the present invention. The rubber compositions were evaluated for material properties using the composition prepared in Example 1, and the results are shown in Table 4 below. 3 is a graph showing the results of an experiment for evaluating tensile strength of a rubber composition according to an embodiment of the present invention. 4 is a graph showing the experimental results of the elongation percentage of the rubber composition according to an embodiment of the present invention.

division Item MS270-05 Evaluation results Remarks T1 T2 T3 T4 T5 T6 Basic Properties Hardness 60 to less than 70 68 68 68 68 68 68 160 DEG C X12min The tensile strength 170 ↑ 176 174 177 177 172 176 Elongation rate 400 ↑ 426 406 420 441 431 435 Aging properties Hs - 3 4 2 2 4 3 70 ° C X70hr ΔTb - -One -One -2 -2 -2 -2 △ Eb - -One -One -3 -2 -3 -4 Hs - 5 4 2 4 5 5 70 ° C X500hr ΔTb - -8 -12 -14 -14 -13 -17 △ Eb - -3 -12 -12 -15 -17 -18 Hs -2 to -8 6 5 3 5 6 5 70 ° C X1000hr ΔTb -20 -16 -16 -17 -19 -18 -19 △ Eb -30 -19 -21 -21 -26 -26 -30 C / set 35 30 30 31 33 31 34 100 占 폚 X22hr Ozone resistance NO CRACK NO CRACK NO CRACK NO CRACK NO CRACK NO CRACK NO CRACK 40 < 0 > C X50pphmX72hr

Property evaluation method

The basic physical properties of rubber are measured by the method of KS M 6784, KS M 6518, KS M 6783, and the measurement methods, definitions and units for each property are as follows. Table 4 above refers to the OEM-HMC standard as a result of the comparison with M270-05.

1) Hardness (HS): (KS M 6784)

The hardness of the rubber refers to the numerical value indicating the resistance of the rubber against the press-in or push-in of a ball or the like which is pressed against the rubber surface.

2) Tensile stress (TS): (KS M 6518) (unit: kgf / cm ² )

It shows the maximum tensile stress when the specimen is broken by pulling it so that the cross-sectional area of the specimen is uniformly loaded.

3) The coefficient of extension

In the tensile test of the material, the elongation of the interstices distance is expressed as a percentage divided by the distance between the original interstices.

4) Aging properties

Aging test: The test is carried out in accordance with KSM 6518 under air circulation at 70 ° C ± 1 ° C for 1000 hours, and then the change in rubber hardness, tensile strength, and elongation percentage are measured using UTM testing equipment. The number of samples to be measured is taken as 4, and the result value is calculated by applying a weighted average value. In the case of the determination of the co-payment of the test, the OEM SPEC shall be judged in due time.

5) Ozone resistance

Ozone test: The test was carried out in accordance with KSM 6518, and in the case of the evaluation conditions, the test specimen for evaluation was stretched by 40 ° C ± 2 ° C × 50 Phhm ± 5 × 20% and left to stand for 72 hours. A: Less cracks / B: More cracks / C: No cracks, depending on whether cracks are present.

Referring to Table 4 and FIGS. 3 and 4, hardness, tensile strength and elongation of T1 without addition of oleic acid were not significantly different from those of T2 to T6 added with oleic acid. However, . In addition, it was confirmed that T1 and T2 to T6 do not show any difference in ozone resistance evaluation.

( Example  3) Products of rubber composition ES  Evaluation experiment

Example 3 was conducted to evaluate the product ES of the self-lubricating rubber composition for bush according to the embodiment of the present invention. The rubber compositions were evaluated for material properties using the composition prepared in Example 1, and the results are shown in Table 5 below.

division direction
SPEC
Evaluation results Measuring section T1 T2 T3 T4 T5 T6 ES Static characteristics
(kgf / mm) P1 110 ± 15%
(93.5 to 126.5) 117.13 118.41 113.02 123.39 120.50 121.08 ± 0.5 to 2 mm P2 40 ± 15%
(34 to 46) 44.81 43.78 44.31 45.95 44.01 45.5 ± 0.5 to 2 mm Magnification P2 2.5 ↓ 1.55 1.65 1.61 1.65 1.70 1.49 15Hz ± 0.1mm Room temperature durability Durability P2 1 million times 1 million pass 1 million pass 1 million pass 1 million pass 1 million pass 1 million pass P2 (load)
30 ± 250 kgf (3 Hz)
Torsion angle S direction ± 10 ° (1 Hz) Durability
69 million cracks 45 million cracks 54 million cracks 43 million cracks 53 million cracks 38 million cracks

ES  Assessment Methods

The ES evaluation of the rubber composition was carried out by measuring the static characteristics, the dynamic ratios, the room temperature durability and the limit durability, respectively.

- static characteristics / dynamic characteristics: MTS 831

- 2 axis endurance tester: CRS 2 axis tester

1) Static Characteristic Test: According to KSM 6604 standard, the sample is preliminarily added or subtracted twice from 0 to P2 for the first time, and kept at load 0 and P2 for 30 seconds, respectively. However, as a rule, the speed of displacement is the speed at which the load between 0 and P2 rises and falls in 30 seconds. The static spring constant is measured in the third load state. The displacement speed is the same as when the preload is applied, and the displacements δ (P1) and δ (P2) are read, and the displacement difference between them is obtained as δ (P2) - δ (P1). The static spring constant is calculated according to the following equation.

K =

2) Magnification: This test is performed to measure the relationship between the load and the flexure of the anti-vibration rubber in the vibration state of the sinusoidal waveform, and then divides the value into the positive characteristic value.

(The vibration state of the sine waveform refers to a case where the flexure-time relationship is a normal vibration and the sine waveform coincides with the sine wave within ± 5% of the peak value)

3) Durability at room temperature: The load (life time) of the product shall be measured by applying the load and angle specified in the direction perpendicular to the axis and the direction of torsion in a tester capable of applying loads in two axes. (The test room temperature shall be 23 ° C ± 5 ° C)

4) Limit Durability: To confirm the limit of the product after the durability at room temperature, it is evaluated by the time of breakage.

Referring to Table 5, it was confirmed that the durability of the product T1 in which oleic acid was not added was lowered in the product ES portion than in the cases of T2 to T6. The self-lubricating rubber composition for bush according to the present invention is remarkably improved when the frictional force and the frictional coefficient are compared with those of the prior art, and the MS and ES endurance performance is also excellent.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. There will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

Claims (6)

With respect to 100 parts by weight of natural rubber,
1 to 5 parts by weight of an oleamide slip, 1.8 to 2.4 parts by weight of an heat resistance promoter, and 55 to 60 parts by weight of carbon black. The method according to claim 1,
Wherein the heat-resistant promoter is one of Tetramethy1-thiuram disulfide or Tetrabutyl thiuram disulfide. The method according to claim 1,
Wherein the carbon black is one of HAF (High abrasion furnace) or FEF (Fast extruding furnace). The method according to claim 1,
Wherein the rubber composition further comprises 5 to 10 parts by weight of zinc oxide, 6.0 to 10.0 parts by weight of a plasticizer, 4.5 to 6.1 parts by weight of an antistatic agent, and 1.5 to 2.4 parts by weight of sulfur. The method according to claim 1,
Wherein the plasticizer is a paraffin-based plasticizer. The method according to claim 1,
Wherein said antistatic agent is an amine-based antistatic agent.

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