KR101491233B1 - Rubber composition having high temperature resistant for hose used cooling system and hose used cooling system using the same - Google Patents

Abstract

The present invention relates to a rubber composition for a high-temperature-resistant cooling system hose and a hose using the same. The present invention relates to a silicone rubber composition comprising 0.5 to 12.0 parts by weight of a filler based on 100 parts by weight of a silicone-organic rubber copolymer in which a silicone rubber and an organic rubber are copolymerized; 0.5 to 3.0 parts by weight of an antioxidant; 0.5 to 6.0 parts by weight of a heat resistance improving agent; And 4.0 to 10.0 parts by weight of a crosslinking agent, and a high heat-resistant cooling system hose comprising the rubber composition. According to the present invention, there is provided a rubber composition comprising a silicone-organic rubber copolymer as a rubber base, wherein each constituent is composed of an appropriate amount, has excellent heat resistance at a temperature of 150 캜 or higher and excellent extrudability, do. In addition, it has excellent mechanical properties such as hardness and tensile strength.

Description

TECHNICAL FIELD [0001] The present invention relates to a rubber composition for a hose having high heat resistance, and a hose using the same. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a rubber composition for a high-temperature-resistant cooling hose and a hose using the rubber composition. More particularly, the present invention relates to a hose using a silicone-organic rubber copolymer as a rubber base, Heat-resistant cooling hose excellent in mechanical properties such as hardness and tensile strength and capable of preventing the outflow of cooling water, and a hose using the rubber composition.

A hose for transporting a fluid (liquid or gas) is required to have properties such as heat resistance, pressure resistance and oil resistance as well as its ease of manufacture and price in the production process. Particularly, a hose used in a cooling system of an automobile is required to have ozone resistance and cooling water resistance as well as heat resistance. If the required physical properties are not sufficiently taken into account, it may lead to breakdown or accident of the components of the automobile, and maintenance work is required continuously.

In general, most hoses, including hoses for use in automobiles, are manufactured from rubber compositions, and in particular hoses for automobiles are manufactured by extruding a rubber composition comprising a rubber base, a filler, an antioxidant and a cross-linking agent. At this time, as a rubber base, acrylic rubber (ACM) or ethylene acrylic rubber (AEM) is mainly used. For example, in the Korean Patent No. 10-0341317 [Prior Patent Document 1], Japanese Patent Application Laid-Open No. P2000-283342 [Prior Patent Document 2], and European Patent 1334995 B1 [Prior Patent Document 3] .

In recent years, due to the high performance of the engine system and the compactness of the engine room, a high temperature of 150 DEG C or more is generated, and such a heat generation temperature is an environment exceeding the heat resistance temperature of the rubber. As a result, the use of a high heat-resistant rubber material having excellent heat resistance has been put to use, and a typical material thereof is silicone rubber.

For example, in Korean Patent Laid-Open No. 10-2008-0019451 [Prior Patent Document 4], there is disclosed a technology for manufacturing a cooling hose for an automobile by extruding a silicone rubber and coating the inner surface with water repellent Teflon by spraying . Here, the reason for applying Teflon is that evaporation of cooling water occurs outside the hose due to the fact that the water molecules generated during the vaporization of the cooling water are smaller than the bonding length of the siloxane (-Si-O-) bond, which is the main chain of the silicone rubber Is described.

For this reason, in the above-mentioned Patent Document 4, leakage of cooling water is prevented by applying Teflon. However, in the case of the above-mentioned Patent Document 4, there is a problem that the manufacturing process is complicated due to the coating process of Teflon, and also the production cost is increased due to the use of expensive Teflon. In addition, silicone rubber has low inherent properties and low green strength. Silicone rubber has such inherent characteristics that it is difficult to maintain its shape after extrusion.

Korea Patent No. 10-0341317 Japanese Patent Laid-Open No. P2000-283342 European patent 1334995 B1 Korean Patent Publication No. 10-2008-0019451

Accordingly, the present invention provides a silicone rubber composition which uses a silicone-organic rubber copolymer as a rubber base, and has an excellent heat resistance at a temperature of 150 ° C or higher and excellent extrudability, And also has excellent mechanical properties such as hardness and tensile strength, and a hose using the rubber composition.

According to an aspect of the present invention,

Based on 100 parts by weight of a silicone-organic rubber copolymer in which a silicone rubber and an organic rubber are copolymerized,

0.5 to 12.0 parts by weight of a filler;

0.5 to 3.0 parts by weight of an antioxidant;

0.5 to 6.0 parts by weight of a heat resistance improving agent; And

And 4.0 to 10.0 parts by weight of a crosslinking agent.

At this time, the silicone rubber has a vinyl group; It is preferable that the main chain of the organic rubber is composed of saturated hydrocarbons and the side chain is bonded to the side chain with a diene system for crosslinking. The silicon-organic rubber copolymer preferably has a weight ratio of silicone rubber to organic rubber of 6: 4 to 7: 3.

Further, according to the present invention,

Rubber inner layer;

A reinforcing layer formed on the rubber inner layer; And

And a rubber outer layer formed on the reinforcing layer,

The rubber inner layer provides a high heat-resistant cooling system hose comprising the rubber composition according to the present invention.

According to the present invention, there is provided a silicone rubber composition comprising a silicone-organic rubber copolymer as a rubber base, wherein the silicone-organic rubber copolymer, filler, antioxidant, heat resistance improver and crosslinking agent are contained in an appropriate amount and have high heat resistance And has an excellent extrudability and an effect of preventing the outflow of cooling water. In addition, it has excellent mechanical properties such as hardness and tensile strength.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a partially cutaway perspective view of a high heat resistant cooling system hose in accordance with an exemplary embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The rubber composition for a high-temperature-resistant cooling hose according to the present invention (hereinafter abbreviated as "rubber composition") comprises a silicone-organic rubber copolymer in which a silicone rubber and an organic rubber are copolymerized, a filler, an antioxidant, . And the constituents are constituted in an appropriate amount. Specifically, the rubber composition according to the present invention comprises 0.5 to 12.0 parts by weight of a filler, 0.5 to 3.0 parts by weight of an antioxidant, 0.5 to 6.0 parts by weight of a heat resistance enhancer, and 4.0 to 10.0 parts by weight of a crosslinking agent, based on 100 parts by weight of the silicone- Parts by weight.

The silicone-organic rubber copolymer is obtained by copolymerization of a silicone rubber and an organic rubber. By using the silicone rubber, the heat resistance and the extrudability are improved, and the cooling water is prevented from flowing out.

The silicone rubber used for copolymerization of the silicone-organic rubber copolymer is not limited as long as it has at least one siloxane (-Si-O-) bond in the main chain. The silicone rubber may be those conventionally used in the art, and preferably one having at least one vinyl group in addition to a siloxane (-Si-O-) bond in the molecule. At this time, the vinyl group forms a bonding structure with the diene system of the organic rubber and is effective in improving the heat resistance and the water resistance.

The organic rubber may be any one that can be copolymerized with the silicone rubber. For example, at least one selected from an ethylene polymer, a propylene polymer, and an ethylene-based and a propylene-based copolymer may be used. The organic rubber preferably has a main chain composed of saturated hydrocarbons and a side chain having one or more dienes bonded thereto for crosslinking. Specific examples of the organic rubber include those in which the main chain is composed of an ethylene-based and propylene-based copolymer, and at least one diene system is bonded to the side chain.

Further, the silicon-organic rubber copolymer preferably has a higher content of the silicone rubber than the content of the organic rubber in consideration of the heat resistance. That is, when high heat resistance is taken into account, it is preferable to polymerize the silicone rubber more than the organic rubber in the copolymerization. At this time, if the content of the silicone rubber is too high, it may be advantageous in terms of heat resistance, but water resistance may be poor. If the content of the silicone rubber is too small, it may be advantageous in water resistance but less in heat resistance. Considering this point, it is preferable that the silicone-based rubber and the organic-based rubber have a weight ratio of 6: 4 to 7: 3. That is, the silicone rubber and the organic rubber are preferably used at a weight ratio of 6: 4 to 7: 3 at the time of polymerization.

The silicone rubber has high heat resistance. This is because the binding force of the siloxane (-Si-O-) in the main chain is about 108 kcal / mol, which is higher than the carbon (-CC-) bonding force (83 kcal / mol) of the main chain of the organic rubber Heat resistance. On the other hand, Si is a group 4 such as C, but Si is two cycles, while Si is three cycles, and its atomic radius is about 1.5 times longer than C. Thereby, a gap through which water molecules can pass can be formed, and the cooling water can flow out (evaporate) to the outside when vaporized. However, when the organic rubber is copolymerized with such a silicone rubber, the water resistance is reinforced.

Therefore, the above-mentioned silicone-organic rubber copolymer has a disadvantage due to the polymerization of the organic rubber while securing the advantages of the silicone rubber, and has high heat resistance of 150 ° C or more and is excellent in water resistance, To prevent. Further, the organic rubber improves the shape retentivity upon extrusion, and is effective in cost reduction by promoting good extrudability and process simplification.

The filler is used for reinforcing the physical properties of the hose, and the filler is not limited as long as it can reinforce the physical properties of the hose. The filler may be at least one selected from the group consisting of, for example, carbon black, silica, calcium carbonate, calcium hydroxide, magnesium hydroxide, titanium oxide, talc, clay and calcium silicate. The filler is preferably at least one selected from among carbon black and silica. In the case of carbon black, it is manufactured by a furnace method and it is preferable to use one having a particle size of 40 μm (micrometer) to 60 μm. The silica is preferably anhydrous silica having a particle size of 5 탆 to 20 탆.

The filler is used in an amount of 0.5 to 12.0 parts by weight based on 100 parts by weight of the silicone-organic rubber copolymer. If the filler content is less than 0.5 part by weight, the hose may have insufficient ability to complement the physical properties. When the content of the filler is more than 12 parts by weight, the viscosity of the rubber composition may increase and the workability may be deteriorated. Considering this point, the filler is preferably used in an amount of 1.0 to 10.0 parts by weight based on 100 parts by weight of the silicone-organic rubber copolymer.

The antioxidant is used for preventing the thermal oxidation of the silicone-organic rubber copolymer, and it is preferable to use at least one selected from, for example, amine type (diphenylamine compound) and mercaptobenzimidazole type . The antioxidant is used in an amount of 0.5 to 3.0 parts by weight based on 100 parts by weight of the silicone-organic rubber copolymer. If the content of the antioxidant is less than 0.5 part by weight, have. When the content of the antioxidant is more than 3.0 parts by weight, the efficiency of the antioxidant is low compared with the excessive use amount of the antioxidant, which may increase the unit cost of the hose. Considering this point, the antioxidant is preferably used in an amount of 1.0 to 2.0 parts by weight based on 100 parts by weight of the silicone-organic rubber copolymer.

The heat resistance improving agent is for improving the heat resistance, and it can be selected from, for example, a transition metal system and the like. Specifically, the heat resistance improving agent can be selected from a compound (oxide, etc.) containing a transition metal and a transition metal. More specifically, one or more selected from iron, nickel and oxides thereof (for example, iron oxide, etc.) may be used. The heat resistance improving agent is used in an amount of 0.5 to 6.0 parts by weight based on 100 parts by weight of the silicone-organic rubber copolymer. When the content of the antioxidant is less than 0.5 parts by weight, the ability to improve heat resistance upon addition thereof is insignificant. When the content of the heat resistance improving agent is more than 3.0 parts by weight, the synergistic effect with the excessive addition is not so large. Considering this point, the heat resistance improving agent is preferably used in an amount of 1.0 to 5.0 parts by weight based on 100 parts by weight of the silicone-organic rubber copolymer.

The cross-linking agent is used for imparting elasticity to the final product (lake) after extrusion. For example, at least one selected from a sulfur compound and a peroxide compound may be used. The crosslinking agent may be used in an amount of 4.0-10.0 parts by weight based on 100 parts by weight of the silicone-organic rubber copolymer. When the content of the crosslinking agent is less than 4.0 parts by weight, crosslinking density may be lowered and deterioration may occur after aging. When the content of the cross-linking agent is more than 10 parts by weight, the cross-linking density becomes dense and the physical properties of a desired standard may not be satisfied due to a decrease phenomenon such as elongation. Considering this point, the crosslinking agent is preferably used in an amount of 5.0 to 9.0 parts by weight based on 100 parts by weight of the silicone-organic rubber copolymer.

In addition, the rubber composition according to the present invention may further include other optional components in addition to these components, including silicone-organic rubber copolymers, fillers, antioxidants, heat resistance improvers and crosslinking agents as described above. As the above-mentioned additional components, those conventionally used in the art can be used. Examples thereof include plasticizers, mold release agents, processing aids, crosslinking aids and color pigments for the processability of the rubber composition.

The rubber composition according to the present invention described above is used for manufacturing a cooling system hose. For example, if the hose comprises an inner rubber layer 10 (see FIG. 1) and an outer rubber layer 30 (see FIG. 1), the rubber composition according to the present invention may be used in the manufacture of an inner rubber layer 10 in direct contact with cooling water It is useful.

Hereinafter, a high-temperature-resistant cooling system hose (hereinafter abbreviated as "hose") according to the present invention will be described with reference to FIG. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a partially cutaway perspective view of a high heat-resistant cooling system hose in accordance with an exemplary embodiment of the present invention.

1, the hose according to the present invention comprises an inner rubber layer 10, a rubber layer 20 formed on the rubber inner layer 10, and a rubber outer layer 20 formed on the rubber layer 20 30). At this time, the rubber inner layer 10 includes the rubber composition according to the present invention. Specifically, the rubber inner layer 10 is formed by extrusion molding from the rubber composition according to the present invention, or comprises at least a rubber composition according to the present invention, . The additional component is not particularly limited, and examples thereof include components commonly added to the rubber hose, for example, a mold release agent, a metal oxide, and the like.

The reinforcing layer 20 is selected from a textile fabric or a non-textile fabric. The reinforcing layer 20 may be composed of, for example, a braided layer formed by covering a knitted fabric woven with fiber yarn on the inner rubber layer 10 as a fabric, or a fiber yarn formed on the inner rubber layer 10 And a winding layer formed by winding.

The reinforcing layer 20 may be made of at least one selected from natural fibers and synthetic fibers. Examples of the fibers include polyester fibers, polyethylene fibers, polyacrylate fibers, paraphenylene terephthalate fibers, Polyphenylene-2,6-benzobisoxazole fiber, carbon fiber, alumina fiber and silicon carbide fiber, or two or more blend yarns selected therefrom can be used.

Preferably, the reinforcing cord layer 20 is made of a material having excellent heat resistance and no change in physical properties with respect to heat because there is no primary and secondary heat transfer temperatures within about 150 ° C to 300 ° C. Considering this point, the reinforcing layer 20 may be formed of a fiber yarn such as an aramid yarn. Amides are amides having an amide bond in an aromatic main chain, and the amides prepared from the amides are excellent in heat resistance properties compared to other fibers such as polyester fibers and are useful in the present invention.

The rubber outer layer 30 is not particularly limited. The rubber outer layer 30 may be formed by using the rubber composition according to the present invention or a conventionally used rubber composition. The rubber outer layer 30 may use a rubber composition comprising at least one rubber base selected from, for example, silicone-based, acrylic-based, fluorinated rubber, and the like. At this time, since the rubber outer layer 30 may be in contact with the external hot oil stream, the rubber base constituting the rubber outer layer 30 may be advantageously used as a silicone rubber which is advantageous in heat resistance and oil resistance.

Also, the hose according to the present invention includes at least the rubber inner layer 10, the reinforcing layer 20, and the rubber outer layer 30, but may further include a separate layer. For example, a coating layer (not shown) may be formed on the inner surface of the rubber inner layer 10 and / or the outer surface of the rubber outer layer 30 for chemical resistance and the like. A separate rubber layer (not shown) or the like may be further formed between the rubber inner layer 10 and the reinforcing layer 20 or between the rubber layer 20 and the outer rubber layer 30 have. At this time, the separate rubber layer may be formed from the rubber composition of the present invention as described above, or may be formed from other rubber composition, and is not particularly limited.

The hose according to the present invention can be produced by extrusion, but the production method thereof is not particularly limited. The hose according to the present invention can be manufactured, for example, in the following manner.

First, compositions for preparing the inner rubber layer 10 and the outer rubber layer 30 are prepared. At this time, at least the rubber inner layer 10 uses the rubber composition according to the present invention. The components other than the cross-linking agent are first kneaded at room temperature by using an internal mixer, and thereafter, a cross-linking agent is added and the kneaded mixture is kneaded in an open roll mill. Next, the kneaded compound is formed into a strip having a width of 40 to 50 mm and a thickness of 10 to 20 mm to prepare a release agent so as not to adhere to each other, and then aged at room temperature for more than 24 hours.

Then, the rubber composition for the rubber inner layer 10 prepared on the strip is injected into an extruder and extruded, and the rubber inner layer 10 is formed by molding into a hollow type. Then, the tuft layer 20 is formed on the rubber inner layer 10 by woven a woven material such as an amide-based yarn. Next, a rubber composition for the rubber outer layer 30 is extruded and coated on the reinforcing layer 20 to form the rubber outer layer 30.

Meanwhile, the hose according to the present invention is used for the purpose of transporting fluids (liquids or gases) in various industrial fields, and can be used for cooling systems of automobiles using cooling water, for example.

According to the present invention described above, it has high heat resistance, high water resistance, and the like, and has excellent mechanical properties. As described above, a silicone-organic rubber copolymer is used as the rubber base. In this case, the disadvantage of the silicone rubber is complemented by the polymerization of the organic rubber while securing the advantages of the silicone rubber of high heat resistance, And at the same time, it is excellent in water resistance to prevent the outflow to the outside when the cooling water is vaporized. Further, the organic rubber improves the shape retentivity upon extrusion, and is effective in cost reduction by promoting good extrudability and process simplification. And mechanical properties such as hardness, tensile strength and elongation are excellent.

Hereinafter, examples and comparative examples of the present invention will be exemplified. The following examples are provided to aid understanding of the present invention, and thus the technical scope of the present invention is not limited thereto. The following examples and comparative examples are intended to illustrate experimental examples for examining changes in mechanical properties depending on the content of each component in various experimental examples for the practice of the present invention.

[Examples 1 to 3]

A rubber composition was prepared as follows according to the ingredients and contents as shown in Table 1 below.

First, a silicone-organic rubber copolymer was prepared, and a mixture prepared by mixing a filler, an antioxidant and a heat resistance-enhancing agent was first kneaded at room temperature through an internal mixer. Then, the mixture was kneaded at room temperature through an open roll-mill after addition of a crosslinking agent.

The silicone-organic rubber copolymer was prepared by copolymerizing silicone rubber and organic rubber in a weight ratio of 6: 4. At the time of copolymerization, a silicone rubber having a vinyl group was used, and an organic rubber was a copolymer of ethylene and propylene, which was bonded to the side chain in a diene system. Carbon black having an average particle size of about 50 탆 was used as the filler, and a diphenylamine compound was used as the antioxidant. The heat resistance improving agent used was nickel (Ni) powder, and the crosslinking agent used was a sulfur compound. At this time, as shown in Table 1 below, the content of the filler, the plasticizer, the antioxidant, the heat resistance improving agent and the cross-linking agent were varied according to each example.

The kneaded compound was formed into a strip in a width of about 45 mm and a thickness of about 15 mm. Then, a releasing agent was applied so as not to adhere to each other, followed by aging at room temperature for about 24 hours.

Next, the aged compound on the strip was poured into an extruder to form an inner layer having a hollow. At this time, the head temperature of the extruder was maintained at about 100 캜 and the screw temperature was maintained at about 60 캜. A reinforcing layer was formed on the extruded rubber inner layer. The reinforcing layer used a knitted fabric of meta-aramid fiber yarn.

Thereafter, a silicone rubber composition was extrusion coated on the reinforcing layer to form an outer layer. The temperature of the extruder is as described above. Thereafter, the release agent was applied to the surface of the extrudate and then inserted into a cylindrical mandrel. And maintained at about 5 atm and about 150 deg. C for about 1 hour to prepare a hose specimen having a laminated structure according to each example.

[Comparative Examples 1 and 2]

The hose specimens were prepared in the same manner as in Example 1, except that the content of each component constituting the rubber composition of the inner layer was changed as shown in Table 1 below.

[Comparative Example 3]

In contrast to Example 3, the same procedure was performed except that a silicone rubber, which is commonly used as a rubber base for the inner layer, was used. The content of each component is as shown in Table 1 below.

              ≪ Component and content of rubber composition (inner layer), unit: part by weight > ingredient
Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Silicon-organic
Rubber copolymer 100 100 100 100 100 - Silicone rubber
- - - - - 100 Filler
One 5 10 15 - 10 Antioxidant
One 1.5 2 2.5 - 2 Heat resistance improver
One 3 5 7 - 5 Cross-linking agent
5 7 9 3 12 9

The properties of the hose specimens prepared according to the above Examples and Comparative Examples were evaluated as follows.

The evaluation of properties was carried out by aging in a gear oven and aging by impregnation in oil as specified in the standard, and evaluating changes in mechanical properties after aging compared with mechanical properties at room temperature. At this time, the aging and impregnation aging evaluation in the oil was based on the specifications given by the automobile manufacturer, and for the items not provided with specifications, a separate standard was set and evaluated as shown in [Table 2]. Specifically, the hardness change, the tensile strength and the elongation percentage change rate after aging at 180 캜 and 200 캜 were measured and evaluated. The hardness change, the tensile strength and the elongation percentage change rate were measured and evaluated after cooling water impregnation aging at 115 ° C and after aging test oil impregnation at 200 ° C.

For the measurement of hardness, shore A type hardness meter based on ISO 7619-1 was used. Specimens were produced in the form of a 2-type dumbbell based on ISO 37 based on tensile strength and elongation, UTM, Universal test machine). The volume change rate was evaluated by using a specific gravity measuring instrument and using difference in specific gravity value between before and after impregnation in cooling water and test oil. The above results are shown in Table 2 below.

                 ≪ Evaluation results of mechanical properties before and after aging > Properties standard Example Comparative Example One 2 3 One 2 3 Room temperature
(Before aging) Hardness (Hs) 70 ± 5 66 70 74 82 61 73 Tensile Strength (Mpa) 9.8 ↑ 9.9 10.3 11.5 8.2 12.4 10.1 Elongation (%) 300 ↑ 432 401 378 456 322 392 180 <
After 168 hours of aging Hardness change (Hs) 20 ↓ 17.1 15.2 14.7 23.1 18.5 10.1 Tensile strength change rate (%) -25 ↓ -14.4 -17.5 -19.1 -21.6 -15.4 -13.5 Rate of elongation change (%) -60 ↓ -45.1 -41.5 -38.7 -61.7 -81.5 -26.6 200 ° C,
After 72 hours aging Hardness change (Hs) 20 ↓ 18.6 16.5 15.1 24.2 20.1 12.3 Tensile strength change rate (%) -25 ↓ -16.2 -18.1 -19.5 -22.4 -17.6 -16.5 Rate of elongation change (%) -60 ↓ -49.5 -45.1 -41.6 -65.8 -90.1 -31.7 115 ° C,
After 360 hours water impregnation Hardness change (Hs) -5 to 10 5.1 4.3 2.9 7.5 3.1 6.5 Tensile strength change rate (%) -20 ↓ -9.1 -10.5 -11.4 -8.6 -13.1 -12.1 Rate of elongation change (%) -40 ↓ -21.4 -19.2 -16.5 -24.1 -15.4 -17.6 Volume change rate (%) -5 to 15 3.4 2.8 2.1 3.8 1.6 21.5 200 ° C,
After 72 hours test oil infusion Hardness change (Hs) -5 to 10 4.5 5.2 3.4 8.2 4.6 5.4 Tensile strength change rate (%) -20 ↓ -9.2 -9.8 -10.1 -9.4 -14.5 -13.5 Rate of elongation change (%) -40 ↓ -19.4 -17.5 -15.8 -25.8 -17.1 -22.3 Volume change rate (%) -5 to 15 3.7 3.1 2.8 3.8 1.5 3.3

The evaluation results shown in Table 2 are compared as follows.

First, in Examples 1 to 3 according to the present invention, it was found that, in the evaluation of physical properties under normal temperature conditions, all of the specimens satisfied the standard range of 70 ± 5 Hs, tensile strength of 9.8 MPa or more, elongation of 300% or more . It can be seen that, in the evaluation of physical properties after aging at 180 ° C for 168 hours, the hardness changes within the standard range of 20 Hs, the tensile strength change rate is within -25%, and the elongation percentage change rate is within -60%. It is also found that when the physical properties after aging at 200 ° C for 72 hours are evaluated, the hardness changes within the standard range of 20 Hs, the tensile strength change rate is within -25%, and the elongation percentage change rate is within -60%.

In Examples 1 to 3 according to the present invention, the hardness changes within the range of -5 to 10 Hs, the tensile strength change rate is within -20%, the elongation percentage change rate -40%, and the volume change rate within -5 ~ 15%. In the evaluation of physical properties after impregnation aging in a test oil at a temperature of 200 ° C for 72 hours, the hardness change within the standard range of -5 to 10 Hs, the tensile strength change rate within -20%, the elongation percentage change rate within -40% And 5 ~ 15%, respectively.

However, it can be seen that the physical properties of Comparative Example 1 deviate from the standard of hardness and tensile strength at the time of evaluating physical properties under normal temperature conditions. Further, in the case of Comparative Example 1, it can be seen that the standard deviates from the hardness change, the elongation percentage change rate, and the volume change rate after aging. In the case of Comparative Example 2, the hardness at the time of evaluating the physical properties at room temperature is lowered, and after aging, it is found that the standard deviates from the hardness change and the elongation percentage change ratio. In addition, in the case of Comparative Example 3, good properties were obtained at the time of evaluating physical properties under a room temperature condition, but it was found that the volume change rate deviated from the specification after cooling water impregnation aging.

As can be seen from the above Experimental Examples, it can be seen that the mechanical properties of the Examples according to the present invention are not only excellent at room temperature but also deteriorated in mechanical properties after aging in a high temperature environment and after cooling water and oil impregnation aging.

10: rubber inner layer 20: reinforcing layer
30: rubber outer layer

Claims (12)

Based on 100 parts by weight of a silicone-organic rubber copolymer in which a silicone rubber and an organic rubber are copolymerized,
0.5 to 12.0 parts by weight of a filler;
0.5 to 3.0 parts by weight of an antioxidant;
0.5 to 6.0 parts by weight of a heat resistance improving agent; And
4.0 to 10.0 parts by weight of a crosslinking agent,
Wherein the silicone rubber and the organic rubber have a weight ratio of 6: 4 to 7: 3.
The method according to claim 1,
The silicone rubber has a vinyl group,
The rubber composition for a high heat-resistant cooling hose according to claim 1, wherein the organic rubber is composed of a main chain of saturated hydrocarbon and a diene system for crosslinking in a side chain.
3. The method of claim 2,
Wherein the main chain of the organic rubber is an ethylene-based and propylene-based copolymer.
The method according to claim 1,
Wherein the silicone-organic rubber copolymer has a silicon-based rubber content higher than that of the organic-based rubber.
delete The method according to claim 1,
Wherein the filler is at least one selected from carbon black and silica,
The carbon black has a particle size of 40 mu m to 60 mu m,
Wherein the silica has a particle size of 5 to 20 占 퐉.
The method according to claim 1,
Wherein the antioxidant is at least one selected from the group consisting of an amine type and a mercaptobenzimidazole type.
The method according to claim 1,
Wherein the heat resistance improving agent is selected from transition metals.
The method according to claim 1,
Wherein the heat resistance improving agent is at least one selected from iron, nickel, and oxides thereof.
The method according to claim 1,
Wherein the crosslinking agent is at least one selected from a sulfur-based compound and a peroxide-based compound.
The method according to claim 1,
The rubber composition may contain,
With respect to 100 parts by weight of the silicone-organic rubber copolymer,
1.0 to 10.0 parts by weight of a filler;
1.0 to 2.0 parts by weight of an antioxidant;
1.0 to 5.0 parts by weight of a heat resistance improving agent; And
And 5.0 to 9.0 parts by weight of a crosslinking agent.
Rubber inner layer;
A reinforcing layer formed on the rubber inner layer; And
And a rubber outer layer formed on the reinforcing layer,
Characterized in that the rubber inner layer comprises the rubber composition according to any one of claims 1 to 4 and 6 to 9.

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