KR20110085592A - Rubber composite for c.v.j boot of vehicle - Google Patents

Abstract

PURPOSE: A rubber composition for constant velocity joint boots is provided to offer the excellent durability of the composition at the severe surrounding condition. CONSTITUTION: A rubber composition for constant velocity joint boots contains the following: a polymer containing heat resistance chlorinated rubber; a plasticizer comprising 5~40phr dioctyl sebacate; and a cross-linking agent containing 2,4,6-trimercapto-S-triazine, -mercapto benzo diazole, and cyclohexylamine.

Description

Rubber composition for constant velocity joint boot applied to vehicle {RUBBER COMPOSITE FOR C.V.J BOOT OF VEHICLE}

The present invention relates to a rubber composition for a constant velocity joint boot, and relates to a rubber composition applicable to a CVJ (Constant Velocity Joint) boot included in a propeller shaft and the like which receives a power generated from an engine and transmits the power from a transmission to a tire. .

The propeller shaft is a shaft that transmits the power of the engine received through the transmission to the differential gear (differential gear) at the rear of the vehicle in the rear wheel roll (FR) or four wheel roll (4WD) vehicle.

Constant velocity joints are used for these propeller shafts. The constant velocity joint is located inside the wheel of the car and acts as a 'joint' that transmits engine power to the wheel. The constant velocity joint can smoothly operate the constant velocity even when the crossing angle between the driving shaft and the driven shaft, which is connected to the tire by the road surface condition, increases. In the constant velocity joint, a corrugated boot is formed at the connection portion between the drive shaft and the driven shaft. The boot is in the form of a sealed rubber bag, the inside of which is filled with grease.

In recent years, as the SUV vehicle becomes larger, the power transmitted to the propeller shaft has increased. This increases the load on the propeller shaft, resulting in an increase in the temperature inside the propeller shaft. Therefore, a boot having excellent heat resistance is required. That is, it is necessary to have heat resistance to 130 degreeC higher than the heat resistance of about 110 degreeC which is conventionally the heat-resistant limit condition of a boot.

In addition, in order for the boot for constant velocity joints to withstand cold regions such as North America and cold weather, it is necessary to have durability up to -40 ° C. By the way, the conventional constant velocity joint boot has only the durability against low temperature of -35 degreeC.

Accordingly, when the driver starts the vehicle at a low temperature or continuously runs at a high temperature, it may cause a malfunction of the propeller shaft.

The present invention has been made in view of the above problems, and an object thereof is to provide a rubber composition for a constant velocity joint boot applied to a vehicle having higher heat resistance and lower temperature.

Therefore, the rubber composition for constant velocity joint boots applied to the vehicle of the present invention contains a polymer, a plasticizer, and a crosslinking agent. The polymer includes heat resistant Chlorinated Rubber. Plasticizers comprise 5 to 40 phr of Dioctyl Sebacate. The crosslinking agent comprises 2,4,6-trimercapto-s-triazine (2.4.6-trimercapto-S-Triazine) and 2-mercapto benzo diazole cyclohexylamine (2-mercapto benzo diazole Cyclohexylamine). .

In this case, the 2,4,6-trimercapto-s-triazine is 0.5 to 5 phr, the 2-mercapto benzo diazole is 1 to 7 phr, and the cyclohexyl amine may be 1 to 7 phr.

In addition, the present invention may further comprise a silicone oil of 1 to 10 phr.

Meanwhile, the present invention may further include 20 to 80 phr of carbon black.

According to the present invention having the above configuration, it is excellent in heat resistance and low temperature, and has excellent durability even in harsh ambient conditions. Therefore, it does not cause malfunction of the propeller shaft during rapid start at low temperature or continuous operation at high temperature.

1 is a cross-sectional view showing an example of the propeller shaft to which the constant velocity joint boot of the present invention is applied.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing an example of the propeller shaft to which the boot for the constant velocity joint of the present invention is applied.

As shown in FIG. 1, a constant velocity joint (CVJ) has an outer ring 102, an inner ring 106, a ball 108, a ball cage 110, and a boot 112. It includes. The outer ring 102 is coupled to the drive shaft 100.

The inner ring 106 is coupled to the driven shaft 104 to receive the power of the outer ring 102.

The ball 108 is disposed between the outer ring 102 and the inner ring 106 to transmit the power of the outer ring 102 to the inner ring 106.

The ball cage 110 is installed outside the inner ring 106 to support the ball 108.

The boot 112 allows the power transmission to be smoothly performed even if the rotation centers of the driving shaft 100 and the driven shaft 104 are not positioned on the same line. One end 112a of the boot 112 is fixed to the outer ring 102 via a boot band 114, and the other end 112b is fixed to the driven shaft 104 through a boot band 116. The boot 112 includes a lubricant G 'to prevent abrasion generated during power transmission.

The rubber composition for a constant velocity joint boot applied to a vehicle according to a preferred embodiment of the present invention includes a polymer, a plasticizer, and a crosslinking agent.

The polymer includes heat resistant Chlorinated Rubber. The heat resistant rubber chloride has heat resistance up to 130 ° C. As an example of the heat resistant rubber chloride, SHOPALON products of Showa Denka Co., Ltd. may be mentioned.

Cross-linking agent (cross-linking agent) is a function of cross-linking the monomers constituting the polymer, also called a vulcanizing agent.

The crosslinking agent includes 2,4,6-trimercapto-S-triazine, and 2-mercapto benzo diazole cyclohexylamine. It is desirable to.

Triazine system, a main crosslinking agent, has excellent processability. In the present invention, 2,4,6-trimercapto-s-triazine (2.4.6-trimercapto-S-Triazine) is used as the triazine system. In this case, the 2,4,6-trimercapto-s-triazine is preferably 0.5 to 5 phr.

The main crosslinking agent includes 2-mercapto benzo diazole cyclohexyl amine as secondary crosslinking agent. The secondary crosslinking agent is for promoting vulcanization, improving crosslinking density, and improving low compression set.

Mercapto benzodiazole is a kind of organic vulcanization accelerator which accelerates vulcanization and shortens vulcanization time. Syick mercapto benzodiazoles speed up the vulcanization rate, shortening the vulcanization time and improving quality.

Cyclohexyl amines improve low compression set. The 2-mercapto benzo diazole cyclohexyl amine is preferably 1 to 7 phr, when using less than 1 phr has no additive effect, when it exceeds 7 phr mechanical properties and aging properties are lowered, so it is difficult to expect desirable properties .

Plasticizers function to improve moldability and flexibility. In other words, when the plasticizer is interposed between the polymer molecules, the direct pulling force between the polymer molecules is weakened, which causes the plastic to bend well. Therefore, the plasticizer must have a property to mix well with the polymer. The plasticizer applied to the present invention may include 5 to 40 phr of dioctyl sebacate (DOS, Dioctyl Sebacate). Use of the DOS as a plasticizer improves particularly low temperature. When the plasticizer is 5 phr or less, it is difficult to achieve a desirable low temperature improvement, and when the plasticizer exceeds 40 phr, moldability is not good.

The processing aid helps the polymers to be mixed homogeneously with other compounding materials in the mixing and mixing of the rubber composition, and adjusts the viscosity of the rubber composition to prevent excessive or insufficient adhesion, and mixing at low temperatures Make it happen smoothly. As a processing aid of the present invention, it may further comprise a silicone oil. The silicone oil improves workability and low temperature operability of the product. It is preferable that the silicone oil has 1 to 10 phr.

On the other hand, the filler reinforcement may further include carbon black. This is to adjust the required physical properties as a boot, for example, hardness, tensile strength and the like. As an example of such carbon black, N990 carbon black can be used. Here, carbon black is a material produced by incomplete combustion or pyrolysis of carbon-containing materials such as natural gas, petroleum, or coal tar-based heavy oil, and has excellent reinforcement because carbon atoms are arranged in a disordered hexagonal shape. The carbon black is preferably 20 to 80 phr.

In the following, the rubber composition according to the embodiment of the present invention as described above (hereinafter referred to as an example for convenience) was tested variously between the properties of a conventional boot rubber composition (hereinafter referred to as a comparative example for convenience) applied to the propeller shaft. By comparing with each other, the above effects are explained more clearly.

In this case, the example used dioctyl sebacate as a plasticizer, and comprised 2,4,6-trimercapto-s-triazine, 2-mercapto benzo diazole, and cyclohexyl amine as a crosslinking agent.

In contrast, in Comparative Example, diisodecyl adipate was used as a plasticizer and ethylene thiourea was used as a crosslinking agent.

Table 1 is a table comparing the physical properties of the Example and Comparative Example results of the heat resistance test and low temperature recovery test. In this case, the heat resistance test was conducted for 70 hours in an ambient atmosphere at 130 ° C, and then the hardness change was satisfied, and the specification of KS M 6518 was satisfied. The low temperature recovery test was a test for deformation recovery in the low temperature region, and the TR-10 cold resistance test was performed. TR-10 is a test that measures the temperature when 10% recovery of 50% of the strain applied.

As a result, the heat resistance test shows that the tensile strength change rate and elongation rate change rate of the examples are 11% and -16%, respectively, while the tensile strength change rate and elongation rate change rate of the comparative example are 15% and -30%, respectively. The example was found to be excellent in the heat test. In addition, the hardness change and the compression ratio in the examples of 4PT and 35%, respectively, in the case of the comparative example it can be seen that the examples are excellent in 12PT and 45%, respectively. This is because heat resistant rubber chloride was used in the examples.

In addition, in the low temperature recovery test, it can be seen that the Example has a lower temperature at −43 ° C., -32 ° C. of the comparative example, and the lower temperature at the time of 10% recovery. This is because DOS is used as a plasticizer.

Through this, it can be seen that the embodiment is excellent in heat resistance and low temperature at the same time.

Item Comparative example Example Heat aging test
(heat aging test)
130 ℃ × 70h Hardness change (PTs) +12 +4 Tensile Strength Change (%) +15 +11 Elongation rate of change (%) -30 -16 Compression rate (%) 45 35 Low temperature recovery test
(TR-10) Recovery temperature (℃) -32 -43

As described above, although described with reference to the preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

102: outer ring 106: inner ring
108: ball 110: ball cage
112: boot

Claims (4)

Polymers including heat resistant Chlorinated Rubber;
Plasticizers comprising 5 to 40 phr of dioctyl sebacate and
2,4,6-trimercapto-S-triazine, including 2-mercapto benzo diazole and cyclohexylamine Crosslinking agents;
Rubber composition for a constant velocity joint boot applied to a vehicle comprising a. The method of claim 1,
The 2,4,6-trimercapto-s-triazine (2.4.6-trimercapto-S-Triazine) is 0.5 to 5 phr, the crosslinking agent for a constant velocity joint boot applied to a vehicle, characterized in that 1 to 7 phr Rubber composition. The method of claim 1,
Rubber composition for a constant velocity joint boot applied to a vehicle further comprising 1 to 10 phr of a silicone-based oil. The method according to any one of claims 1 to 3,
Rubber composition for a constant velocity joint boot applied to a vehicle further comprising 20 to 80 phr of carbon black.

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