KR20050112955A - Automotive rubber hose - Google Patents

Abstract

Through the rubber hose for automobiles according to the present invention there is an effect of minimizing the decrease in workability and the increase in price and the durability of the rubber hose for automobiles improved. Such automotive rubber hose has an effect obtained by including a power steering rubber hose having excellent processability and impulse characteristics and minimizing the price increase. The present invention includes an inner tube, a first reinforcing layer, an intermediate rubber layer, a second reinforcing layer, an outer layer tube of a rubber hose for automobiles, wherein the inner layer tube and the outer layer tube are hydrogenated acrylonitrile butadiene copolymers or It provides a rubber hose for automobiles, characterized in that at least one of the chlorinated polyethylene.

Description

Automotive Rubber Hose {AUTOMOTIVE RUBBER HOSE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to rubber hoses for automobiles and, more particularly, to rubber hoses for high processing, high durability hydraulic steering devices used in automotive steering devices.

A typical automotive rubber hose has a structure as shown in FIG. Rubber hoses used in automobiles can be divided into high pressure hoses and low pressure hoses according to the operating pressure environment. Thus, rubber hoses can be divided into the presence or absence of a reinforcement layer and a case where a first reinforcement layer or a second reinforcement layer is applied. .

In addition, a variety of rubber materials are used in the inner and outer layers depending on which purpose is used for which part in the vehicle. Rubber hoses used in automobiles can be broadly divided into chassis hoses and engine hoses, and chassis hoses can be divided into automatic transmissions, hydraulic steering systems, and brake systems. Engine hoses can be classified for use in fuel systems, intake and exhaust systems, cooling systems and heater systems.

These rubber hoses are selected according to the type, temperature and ambient temperature of the fluid flowing in the rubber material, and made into a composition that meets the required characteristics and used as the inner, outer and middle rubber layers.

Recent automobile technology is progressing in the direction of improving fuel and engine performance, lightening weight and high performance according to the regulation of environmental pollution by exhaust gas, and thus increasing the temperature of the engine room and working fluid and extending the life of the working fluids. It is accompanied by chemical additives to make the rubber hose more harsh. Due to this environment, higher heat resistance and oil resistance improvement are required. In particular, rubber hoses, ie, power steering rubber hoses used in hydraulic steering systems, have a need for materials capable of withstanding such harsh use environments.

Such a power steering rubber hose has conventionally used acrylonitrile butadiene rubber (NBR) in its inner layer and chloroprene rubber (CR) in its outer layer. Recently, however, as the use environment is severe, chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), and hydrogenated acrylonitrile butadiene rubber (HNBR) having excellent heat resistance and oil resistance have been used.

This demand is a trend to convert acrylonitrile butadiene rubber, which has been widely used, to chlorosulfonated polyethylene, chlorinated polyethylene, and hydrogenated acrylonitrile butadiene rubber having excellent heat resistance and oil resistance.

In the case of acrylonitrile butadiene rubber and chloroprene rubber, the maximum operating temperature is known to be in the range of 100 ° C to 120 ° C, which is considered to be beyond the limit of the operating environment due to the increase in engine room temperature due to high power, high performance and exhaust gas regulation. It is becoming. As a result, materials such as chlorosulfonated polyethylene, chlorinated polyethylene, and hydrogenated acrylonitrile butadiene rubber, which have higher heat resistance and oil resistance, have been used. According to them, they are evaluated to have heat resistance and oil resistance of 150 ° C. to 160 ° C. depending on the appropriate formulation.

The reliability of the power steering rubber hose used in high temperature and high pressure oil can be evaluated by high temperature impulse test, using the power steering oil of about 150 ℃, and the ambient temperature of 135 ℃, 0kg / ㎠ To 140kg / cm 2 repeatedly is applied to measure the burst time or number of hoses.

1 is a structural diagram showing the structure of a conventional rubber hose, in which the acrylonitrile butadiene rubber is used for the inner layer 5 and the chloroprene rubber is used for the outer layer 1. However, as the use environment becomes more severe, there is a demand for improving heat resistance, oil resistance, and lifespan. Therefore, materials such as chlorosulfonated polyethylene, chlorinated polyethylene, and hydrogenated acrylonitrile butadiene are being used. Sulfonated polyethylene has insufficient high temperature impulse life, and when hydrogenated acrylonitrile butadiene rubber is used, the high temperature impulse life is excellent, but the roll workability is poor and the application is limited due to the increase in price.

Instead of acrylonitrile butadiene rubber and chloroprene rubber in the environment of the use of automobile hose such as the increase of oil temperature due to the improvement of automobile technology, the increase of combustion efficiency according to the exhaust gas regulation and the increase of engine room temperature due to the high integration Chlorosulfonated polyethylene, chlorinated polyethylene, hydrogenated acrylonitrile butadiene, etc. which are excellent in heat resistance and oil resistance are applied.

Chlorosulfonated polyethylene, chlorinated polyethylene, etc. used in the prior art have insufficient high temperature impulse life, and when hydrogenated acrylonitrile butadiene rubber is used, the high temperature impulse life is excellent, but the roll processability is poor and the price increases. This limited problem requires a rubber hose and a power steering rubber hose having excellent high temperature impulse characteristics, which are not deteriorated in workability and are not expensive.

An object of the present invention is to provide a rubber hose for automobiles to minimize the degradation of workability and increase the price in order to solve the above problems. These automotive rubber hoses are power steering rubber hoses that have excellent processability and impulse characteristics and minimize price increases.

The above object is a rubber hose for an automobile, comprising an inner layer tube, a first reinforcement layer, a middle rubber layer, a second reinforcement layer, an outer layer tube of the inner rubber tube, the inner layer tube and the outer layer tube May be made through a rubber hose for automobiles, characterized in that at least one of hydrogenated acrylonitrile butadiene copolymer or chlorinated polyethylene.

In addition, the above object can also be achieved through the rubber hose for automobiles, characterized in that the content of the chlorinated polyethylene is 20% by weight to 40% by weight relative to the total amount with the hydrogenated acrylonitrile butadiene copolymer.

In addition, the above object can also be achieved through a rubber hose for automobiles, characterized in that the chlorine content of the chlorinated polyethylene is 28% to 36% and the Mooney viscosity is 90 or less.

In addition, the above object can also be achieved through a rubber hose for automobiles, characterized in that the inner layer tube and the outer layer tube is peroxide crosslinked.

It is also an object that the peroxide is at least one of dicumyl peroxide, bistert butyl peroxy isopropyl benzene or 1,1-ditert butyl peroxy-3,3,5-trimethyl cyclohexane It can also be made via a rubber hose.

In addition, the above object can be achieved through the rubber hose for automobile, characterized in that the first reinforcement layer and the second reinforcement layer is at least one of nylon, polyester, vinylon.

In addition, the object can also be achieved through the rubber hose for automobiles, characterized in that the intermediate rubber layer is at least one of natural rubber, chloroprene or chlorinated polyethylene.

Hereinafter, the rubber hose for automobile according to the present invention will be described in detail with reference to the configuration of the present invention.

As shown in FIG. 1, the rubber hose for automobiles according to the present invention has an inner layer tube 1, a first reinforcement layer 2, an intermediate rubber layer 3, a second reinforcement layer 4, and an outer layer tube 5 from the inside. It consists of). In the rubber hose for automobile according to the present invention, that is, the power steering hose of the automobile, the change of the composition of the inner layer tube and the outer layer tube is important for minimizing the deterioration of workability and the increase of the price and the improvement of the high temperature impulse performance related to the endurance life. . Therefore, in the present invention, the inner tube 1 and the outer tube 5 will be described.

The inner layer tube (1) and the outer layer tube (5) of the present invention consist of a peroxide crosslinking mixture of chlorinated polyethylene and hydrogenated acrylonitrile butadiene alone or a mixture thereof, and the outer surface of the inner layer tube includes nylon, polyester, vinylon, and the like. It is composed of a first reinforcing yarn layer (2) which can be used alone or in combination, and an intermediate rubber layer (3) made of natural rubber, chloroprene rubber or cloned polyethylene, and a second reinforcing yarn layer (4) on the outer surface thereof.

The present invention is to provide a rubber hose for automobiles which minimizes the decrease in processability and the increase in price and improves durability. In particular, the present invention relates to a power steering hose used in a hydraulic steering system.

The rubber composition of the inner layer tube 1 and the outer layer tube 5 in the rubber hose according to the present invention is characterized in that 20% to 40% by weight of the cloned polyethylene is mixed with respect to the total amount of the hydrogenated acrylonitrile butadiene. It is done. The chlorine content of the cloned polyethylene is 28% to 36%, and has a Mooney viscosity indicating a molecular weight of 90 or less.

The reason for mixing 20 wt% to 40 wt% of chlorinated polyethylene with respect to the total amount of hydrogenated acrylonitrile butadiene is that it is not effective to improve roll processability when mixed below 20 wt%, and more than 40 wt% This is because the high temperature impulse life and oil resistance are drastically reduced.

Further, the reason for limiting the chlorine content of the chlorinated polyethylene to 28% to 36% is that the oil resistance deteriorates at 28% or less, and the cold resistance falls at 36% or more. The Mooney viscosity of the chlorinated polyethylene is defined to be 90 or less because the disadvantage of workability is reduced when the chlorinated polyethylene having a viscosity of 90 or more is mixed. However, in the present invention, the rubber composition of the inner layer tube and the outer layer tube is not limited to the cloned polyethylene and the hydrogenated acrylonitrile butadiene, and other chemicals having the same functional effect as a whole are included in the present invention.

The crosslinking system used peroxide crosslinking. Peroxides include Di cumyl peroxide, bistert butyl peroxy isopropyl benzene [bis- (tert.butyl peroxyisopropyl) benzene], 1,1-dibutyl butyl peroxy-3,3,5-trimethyl cyclic Rohexane [1,1-di-tert. butylperoxy-3,3,5, -trimetylcyclohexane] may be used alone or in combination.

As mentioned above, in the automotive rubber hose according to the present invention, by using the cloned polyethylene and the hydrogenated acrylonitrile butadiene as the rubber composition of the inner layer tube and the outer layer tube, the present invention minimizes the processability and the price increase and the durability This improved automotive rubber hose can be provided.

Hereinafter, the rubber hose for an automobile according to the present invention will be described in more detail with reference to the embodiment of the present invention and a conventional comparative example.

Table 1 below is a table showing the component content ratio of the preferred embodiment according to the present invention.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 HNBR 80 70 60 80 80 60 60 60 CPE 20 30 40 CPE Cl content (30%) 20 CPE Cl content (36%) 20 CPE Pattern Viscosity (ML 1 + 4, 42) 40 CPE Pattern Viscosity (ML 1 + 4, 65) 40 CPE Pattern Viscosity (ML 1 + 4, 80) 40 Carbon Black (GPF) 85 85 85 85 85 85 85 85 ZnO 5 5 5 5 5 5 5 5 Peroxide 2.8 2.8 2.8 2.8 2.8 2.8 2.8 2.8 TAIC 3 3 3 3 3 3 3 3 Antioxidant 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 Stearic acid 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 Plasticizer 10 10 10 10 10 10 10 10

Each value in the Examples and Comparative Examples is weight percent, and the polymer composition is kneaded using a kneader or Banbury mixer, which is an open roll or a closed kneading facility, into a sheet state. The test specimen was prepared by press molding at 170 ° C. for 20 to 30 minutes using an electric heating press, and then subjected to room temperature and oil resistance tests.

The inner layer tube 1 and the outer layer tube 5 of the representative rubber hose of the present invention shown in FIG. 1 are composed of chlorinated polyethylene and hydrogenated acrylonitrile butadiene, and the chlorinated polyethylene is hydrogenated acrylonitrile butadiene. It consists of 20 to 40% by weight relative to the total amount of.

The first reinforcing yarn layer 2 and the second reinforcing yarn layer 4 are made of nylon, and the middle rubber layer 3 is made of natural rubber (NR). With respect to the above configuration, a hose was prepared for the compositions of Examples 1 to 3 and Comparative Examples 1 to 4 to evaluate high-temperature impulse characteristics.

Hydrogenated acrylonitrile butadiene had a hydrogenation degree of 97%, an acrylonitrile content of 34%, and a pattern viscosity of 70. A carbon black, an antioxidant, a plasticizer and a crosslinking aid, a crosslinking agent, and the like were forcibly packed.

The test for the characteristic evaluation,

Oil resistance test: The extension residual and volume change rate were measured after 168 hours immersion at an oil temperature of 150 ° C. using a power steering oil as test oil.

-Roll workability: The workability in the surface temperature of 100 degreeC was evaluated using the 12-inch roll of 15 rpm of the front roll, and 12.5 rpm of the rear roll.

-High temperature impulse life: Measure the time until the hose ruptures by repeatedly applying a hydraulic pressure of 0kg / ㎠ to 140kg / ㎠ at a cycle of about 35CPM at a power steering oil temperature 150 ℃, ambient temperature 135 ℃ to the manufactured hose Relative evaluation was performed based on Comparative Example 4. Table 2 below is a table showing the component content ratio of the comparative examples compared with the present invention.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 HNBR 100 90 50 - 80 80 60 CPE - 10 50 100 - - - CPE Cl content (25%) - - - - 20 - - CPE Cl content (42%) - - - - - 20 - CPE Pattern Viscosity (ML 1 + 4, 94) - - - - - - 40 Carbon Black (GPF) 85 85 85 85 85 85 85 ZnO 5 5 5 5 5 5 5 Peroxide 2.8 2.8 2.8 2.8 2.8 2.8 2.8 TAIC 3 3 3 3 3 3 33 Antioxidant 1.2 1.2 1.2 1.2 1.2 1.2 1.2 Stearic acid 0.7 0.7 0.7 0.7 0.7 0.7 0.7 Plasticizer 10 10 10 10 10 10 10

Table 3 below is a table in which various properties were measured by comparing the Examples and Comparative Examples.

Example Comparative example characteristic Evaluation item One 2 3 4 5 6 7 8 One 2 3 4 5 6 7 Room temperature characteristics 1) tensile strength (kg / mm ² ) 2.0 1.9 1.87 1.7 2.05 1.9 1.92 1.93 2.15 2.10 1.81 1.68 2.19 2.19 1.98 1) Elongation (%) 330 325 340 326 325 350 335 352 300 345 380 344 268 268 300 Shore A 79 79 79 78 78 78 78 78 78 78 80 82 84 84 82 Oil resistance (150 ℃ × 168hr) 2) Elongation remaining rate (%) 80 85 78 86 84 - - - 85 86 65 85 86 86 - 2) Volume change (%) 13 16 18 40 35 - - - 9 11 21 45 55 10 - Cold resistance Breakdown temperature (℃) - - - -40 -40 - - - - - - - -43 -25 - Impulse Life (Hose) 1.9 1.7 1.5 - - - - - 2.0 1.9 1.1 1.0 - - - roll processability ◎ ◎ ◎ ◎ ◎ ◎ × × ◎ ◎ ×

As can be seen from the evaluation results of the Examples and Comparative Examples Comparative composition 1 consisting only of hydrogenated acrylonitrile butadiene and Comparative Example 2 containing 10% chlorinated polyethylene is excellent in high temperature impulse life but poor roll processability, In Comparative Example 3 containing 50% of chlorinated polyethylene, the roll workability is excellent, but the high temperature impulse life is as low as 1.1.

In the case of Examples 1 to 3 in which the chlorinated polyethylene is mixed with 20% to 40%, it can be seen that excellent impulse life and roll processability are shown.

In addition, the chlorine content of the chlorinated polyethylene affects the oil resistance and cold resistance, and in Comparative Example 5 having a chlorine content of 25% or less, the oil resistance rapidly deteriorated, resulting in a volume change rate of 55%. Comparative Example 6 was excellent in oil resistance, but the cold resistance was deteriorated to -25 ℃, Example 4 and Example 5 having a chlorine content of 30% to 36%, it can be seen that the lowering of oil resistance and cold resistance is not large. have.

As a result of evaluating room temperature characteristics and roll workability according to the Mooney viscosity of the applied chlorinated polyethylene, when the Mooney viscosity was 94 or more, the roll workability was not good as in Comparative Example 7, resulting in many difficulties in the work. Mooney viscosity 42, 65 In the case of, 80, the roll workability was greatly improved.

As described above in the Comparative Examples and Examples, the power steering hose applied to the rubber hose, in particular, the steering system, provided by the present invention has a weight ratio of 20 wt% to 40 wt% based on the total amount of the hydrogenated acrylonitrile butadiene in the inner and outer layers. It contains a chlorinated polyethylene of and crosslinked by a peroxide, thereby minimizing a decrease in processability and an increase in price and providing excellent high temperature impulse characteristics.

The present invention has been described in more detail by describing preferred embodiments and comparative examples. However, the scope of the present invention is not limited to the above embodiments but may be embodied in various forms of embodiments within the appended claims. Without departing from the gist of the invention as claimed in the claims, any person of ordinary skill in the art is considered to be within the scope of the claims described in the present invention to the extent possible to vary.

The present invention has the effect of minimizing the decrease in workability and the increase in price through the rubber hose for automobiles according to the present invention and the durability of the rubber hose for automobiles with improved durability. Such automotive rubber hose has an effect obtained by including a power steering rubber hose having excellent processability and impulse characteristics and minimizing the price increase.

Although the invention has been described with reference to the preferred embodiments mentioned above, many other possible modifications and variations can be made without departing from the spirit and scope of the invention. Accordingly, the appended claims are intended to cover such modifications and variations as fall within the true scope of the invention.

1 is a structural diagram of a rubber hose for a conventional vehicle.

<Brief description of the main parts of the drawing>

1. inner layer tube,

2. first reinforcement layer;

3. middle rubber layer,

4. second reinforcement layer;

5. Outer layer tube.

Claims (7)

In the rubber hose for automobiles, An inner layer tube, a first reinforcement layer, a middle rubber layer, a second reinforcement layer, an outer layer tube of the rubber hose for the automobile, the inner layer tube and the outer layer tube is a hydrogenated acrylonitrile butadiene copolymer or chlorine Rubber hose for automobiles, characterized in that at least one of the polyethylene. The rubber hose for automobile according to claim 1, wherein the content of the chlorinated polyethylene is 20% by weight to 40% by weight based on the total amount with the hydrogenated acrylonitrile butadiene copolymer. The rubber hose for automobile according to claim 1, wherein the chlorinated polyethylene has a chlorine content of 28% to 36% and a Mooney viscosity of 90 or less. The rubber hose of claim 1, wherein the inner tube and the outer tube are peroxide crosslinked. 5. The method of claim 4, wherein the peroxide is at least one of dicumyl peroxide, bistert butyl peroxy isopropyl benzene or 1,1-ditert butyl peroxy-3,3,5-trimethyl cyclohexane. Rubber hoses for cars. The rubber hose of claim 1, wherein the first reinforcing yarn layer and the second reinforcing yarn layer are at least one of nylon, polyester, and vinylon. The rubber hose of claim 1, wherein the intermediate rubber layer is at least one of natural rubber, chloroprene, or chlorinated polyethylene.