KR20240063218A - Radiator hose composition for automobiles - Google Patents

Abstract

The present invention relates to a radiator hose composition for automobiles.
In this invention, 3 to 10 parts by weight of a compatibilizer and 100 to 120 parts by weight of carbon black are used for 100 parts by weight of a rubber base consisting of 80 to 95 parts by weight of EPDM (ethylene propylene diene monomer) rubber and 5 to 20 parts by weight of silicone rubber. The technical gist is that it is formed by containing 10 to 50 parts by weight of calcium carbonate with a particle size of 0.1 ㎛ or less and surface-treated with fatty acid, and 30 to 50 parts by weight of a hydrocarbon-based process oil with a paraffin structure content of 70% or more.

Description

Radiator hose composition for automobiles {RADIATOR HOSE COMPOSITION FOR AUTOMOBILES}

The present invention relates to a radiator hose composition for automobiles.

In general, the radiator hose is a hose used as a transfer path for coolant that connects the engine and the radiator to cool the engine and engine oil. It is composed of a composite of inner rubber, braided yarn, and outer rubber, and has high temperature durability, liquid resistance, and pressure resistance. etc. are required.

Conventionally, rubber such as styrene-butadiene rubber (SBR), natural rubber (NR), or chloroprene rubber (CR) was used as the material for radiator hoses, but with the increase in performance and efficiency to improve the fuel efficiency of automobile engines, thermal efficiency has been improved. As the temperature for cooling water management has increased, it has been replaced with ethylene propylene diene monomer rubber (EPDM) since the 2000s.

To improve heat resistance in EPDM-based composite rubber materials, there are common methods such as applying EPDM with high molecular weight and low ENB content, increasing the content of paraffin-based processing oil, and applying a peroxide cross-linking system.

For example, in 'Automotive radiator hose rubber with excellent heat resistance and durability and nanocomposite composition for the same (KR 10-2009-0042631 A)', organic polymers are added to gelled clay through hydration and cation exchange of water-swellable clay in molten EPDM. It is manufactured by adding and mixing nanoclay and carbon black obtained by adding a topical agent to exfoliate to form nanoparticles and then drying them, the water-swellable clay is bentonite, and the organicizing agent is Na ₂ CO ₃ or Na ₂ SiO ₃ is starting.

However, there is a need to go through a gelation process such as cation exchange, and there are still limits to improving heat resistance due to problems with physical properties, extrudability, and productivity. Therefore, there is a need to develop technology for radiator hose compositions to solve this problem.

KR 10-2009-0042631 A KR 10-1504940 B1

The present invention was invented to solve the above problems, and the technical problem is to provide a radiator hose composition for automobiles that improves high-temperature durability to cope with high-efficiency engines.

In order to solve the above technical problem, the present invention is a composition of 3 to 10 parts by weight of a compatibilizer, based on 100 parts by weight of a rubber base consisting of 80 to 95 parts by weight of EPDM (ethylene propylene diene monomer) rubber and 5 to 20 parts by weight of silicone rubber. Provided is a radiator hose composition for an automobile, characterized in that it comprises 100 to 120 parts by weight of carbon black, 10 to 50 parts by weight of calcium carbonate, and 30 to 50 parts by weight of a hydrocarbon-based process oil with a paraffin structure content of 70% or more.

In the present invention, the calcium carbonate has a particle size of 0.1 ㎛ or less and is surface-treated with fatty acid.

In the present invention, the compatibilizer is characterized in that it is modified EPDM (modified EPDM).

According to the present invention as a means of solving the above problem, the interface between EPDM rubber and silicone rubber is controlled to enhance compatibility to form a rubber composition that can secure high temperature durability above 150 ℃, and this is applied to an automobile radiator hose. There is an effect that can be utilized.

In addition, through the optimal composition of the carbon black of the present invention, a hydrocarbon-based process oil with a particle size of 0.1 ㎛ or less, calcium carbonate surface-treated with fatty acid, and a paraffin structure content of 70% or more, an increase in compounding cost due to the introduction of silicone rubber is prevented. It can secure economic feasibility and has the effect of improving extrusion into radiator hoses.

Since the present invention can be subject to various changes and can have various forms, embodiments will be described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Throughout the specification, when a part is said to “include” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as having an ideal or excessively formal meaning unless clearly defined in this specification. .

The terms used herein are merely used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

The present invention relates to a radiator hose composition for automobiles. The radiator hose composition of the present invention contains 3 to 10 parts by weight of a compatibilizer and 100 to 100 parts by weight of carbon black, based on 100 parts by weight of a rubber base consisting of 80 to 95 parts by weight of EPDM (ethylene propylene diene monomer) rubber and 5 to 20 parts by weight of silicone rubber. It is characterized in that it is formed by comprising 120 parts by weight, 10 to 50 parts by weight of calcium carbonate with a particle size of 0.1 ㎛ or less and surface treated with fatty acid, and 30 to 50 parts by weight of hydrocarbon-based process oil with a paraffin structure content of 70% or more.

The rubber base forms the base of the radiator hose composition and consists of 80 to 95 parts by weight of EPDM (ethylene propylene diene monomer) rubber and 5 to 20 parts by weight of silicone rubber.

If the amount of EPDM rubber is less than 80 parts by weight or more than 95 parts by weight, there is a disadvantage in that an excessive amount of compatibilizer must be used due to a decrease in miscibility with silicone rubber. Not only does the internal pressure of the radiator hose decrease, but the radiator hose may crack when observing high temperature durability. This can happen. If the amount of silicone rubber is less than 5 parts by weight or exceeds 20 parts by weight, the physical properties of the radiator hose composition may be impaired due to low miscibility with EPDM rubber. In particular, if the amount of silicone rubber exceeds 20 parts by weight, there is a problem of increased unit price, so 20 parts by weight It is desirable to add not to exceed the amount. For the above reasons, it is preferable that the high-part substrate is formed by mixing 80 to 95 parts by weight and 5 to 20 parts by weight of EPDM rubber and silicone rubber, respectively.

In general, polymers of different polarity do not mix well, and compatibilizers are used to improve this. Modified EPDM is a product in which functional compounds such as maleic anhydride and acrylic acid are grafted onto the ends of EPDM, and is similar to EPDM rubber. It functions as a compatibilizer that allows polymers of different polarities to mix well.

That is, modified EPDM is a compatibilizer and can be contained in the range of 3 to 10 parts by weight based on 100 parts by weight of the rubber base. If modified EPDM is mixed in an amount of less than 3 parts by weight based on 100 parts by weight of the rubber base, the miscibility between EPDM rubber and silicone rubber cannot be increased and the productability as a radiator hose is not achieved. If it exceeds 10 parts by weight, the radiator hose composition is not suitable for use. It is necessary to be careful about adding excessive amounts as it can deteriorate high temperature durability characteristics.

Carbon black can improve the reinforcement properties of radiator hose compositions and have a beneficial effect on physical properties such as hardness, tensile strength, and elongation. If the carbon black is outside the range of 100 to 120 parts by weight based on 100 parts by weight of the rubber base, the hardness, tensile strength, and elongation values required for the radiator hose cannot be satisfied.

Calcium carbonate has a particle size of 0.1 ㎛ or less and is surface-treated with fatty acid, and may be included in the range of 10 to 50 parts by weight based on 100 parts by weight of the rubber base.

In general, light calcium carbonate with a particle size of 1 to 3 ㎛ is widely used, but in the present invention, in order to minimize the effect on physical properties and improve extrudability, the particle size of calcium carbonate was set to 0.1 ㎛ or less, and the surface was treated with fatty acid. Therefore, ultrafine calcium carbonate with surface modification is used.

If calcium carbonate is added in an amount of less than 10 parts by weight based on 100 parts by weight of the rubber base, the radiator hose composition will have poor moldability due to reduced extrudability, and if it exceeds 50 parts by weight, it may greatly affect the physical properties of the radiator hose, which is not desirable. not.

Usually, among hydrocarbon-based process oils with paraffin, naphthene, and aromatic structures, paraffin-based process oils with excellent heat resistance and a paraffin structure content of 63 to 69% and an aromatic structure content of 2 to 5% are used. However, in the present invention, paraffin-based process oils with excellent heat resistance are used. Use hydrocarbon-based process oil with a content of more than 70% and an aromatic structure content of 0%.

Hydrocarbon-based process oil with a paraffin structure content of 70% or more can be mixed in the range of 30 to 50 parts by weight based on 100 parts by weight of the rubber base. If the paraffin structure content of the process oil is less than 70%, it is not effective in improving the heat resistance of the radiator hose. Also, even if less than 30 parts by weight of process oil is mixed, it is ineffective in increasing the heat resistance of the radiator hose. On the other hand, if the hydrocarbon-based process oil with a paraffin structure content of 70% or more exceeds 50 parts by weight based on 100 parts by weight of the rubber base, durability may be reduced when molded into a radiator hose.

Through the optimal composition of the carbon black of the present invention as described above, a hydrocarbon-based process oil with a particle size of 0.1 ㎛ or less, calcium carbonate surface-treated with fatty acid, and a paraffin structure content of more than 70%, an increase in compounding cost due to the introduction of silicone rubber is prevented. This ensures economic efficiency and also has the advantage of improving extrusion into the radiator hose.

Hereinafter, embodiments of the present invention will be described in more detail as follows. However, the following examples are merely illustrative to aid understanding of the present invention and are not intended to limit the scope of the present invention.

<Example 1>

For 100 parts by weight of a rubber base consisting of 95 parts by weight of EPDM rubber and 5 parts by weight of silicone rubber, 3 parts by weight of modified EPDM, 100 parts by weight of carbon black, 30 parts by weight of ultrafine calcium carbonate with a particle size of 0.1 ㎛ or less and surface treated with fatty acid, 40 parts by weight of hydrocarbon process oil with a paraffin structure content of 70% or more, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 2 parts by weight of polyethylene glycol, and 1.5 parts by weight of an anti-aging agent were mixed at 100°C using a kneader, a compound kneader. A compound was prepared by kneading for about 10 minutes. After the kneader work was completed, the compound was left at room temperature for about 24 hours to mature, and then 2 parts by weight of the peroxide cross-linker and 0.5 parts by weight of the co-cross-linker were additionally mixed in an open roll mill and dispersed uniformly for 5 minutes to prepare a 5 mm sheet-like compound. . The sheet-like compound prepared in this way was put into a mold manufactured according to the test standard, and then molded for about 10 minutes under press conditions of 170°C and 150 kgf/cm ² to prepare a specimen.

<Example 2>

For 100 parts by weight of a rubber base consisting of 85 parts by weight of EPDM rubber and 15 parts by weight of silicone rubber, 5 parts by weight of modified EPDM, 100 parts by weight of carbon black, 30 parts by weight of ultrafine calcium carbonate with a particle size of 0.1 ㎛ or less and surface treated with fatty acid, 40 parts by weight of hydrocarbon process oil with a paraffin structure content of 70% or more, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 2 parts by weight of polyethylene glycol, and 1.5 parts by weight of an anti-aging agent were mixed at 100°C using a kneader, a compound kneader. A compound was prepared by kneading for about 10 minutes. After the kneader work was completed, the compound was left at room temperature for about 24 hours to mature, and then 2 parts by weight of the peroxide cross-linker and 0.5 parts by weight of the co-cross-linker were additionally mixed in an open roll mill and dispersed uniformly for 5 minutes to prepare a 5 mm sheet-like compound. . The sheet-like compound prepared in this way was put into a mold manufactured according to the test standard, and then molded for about 10 minutes under press conditions of 170°C and 150 kgf/cm ² to prepare a specimen.

<Example 3>

For 100 parts by weight of a rubber base consisting of 95 parts by weight of EPDM rubber and 5 parts by weight of silicone rubber, 3 parts by weight of modified EPDM, 100 parts by weight of carbon black, 50 parts by weight of ultrafine calcium carbonate with a particle size of 0.1 ㎛ or less and surface treated with fatty acid, 50 parts by weight of hydrocarbon process oil with a paraffin structure content of 70% or more, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 2 parts by weight of polyethylene glycol, and 1.5 parts by weight of an anti-aging agent were mixed at 100°C using a kneader, a compound kneader. A compound was prepared by kneading for about 10 minutes. After the kneader work was completed, the compound was left at room temperature for about 24 hours to mature, and then 2 parts by weight of peroxide cross-linker and 0.5 parts by weight of co-cross-linker were additionally mixed in an open roll mill and dispersed uniformly for 5 minutes to prepare a 5 mm sheet-like compound. . The sheet-like compound prepared in this way was put into a mold manufactured according to the test standard, and then molded for about 10 minutes under press conditions of 170°C and 150 kgf/cm ² to prepare a specimen.

<Comparative Example 1>

For 100 parts by weight of a rubber base consisting of 100 parts by weight of EPDM rubber, 120 parts by weight of carbon black, 40 parts by weight of process oil with a paraffin structure content of 63% and an aromatic structure content of 5%, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, A compound was prepared by mixing 2 parts by weight of polyethylene glycol and 1.5 parts by weight of an anti-aging agent at 100° C. for about 10 minutes using a kneader, a compound kneader. After the kneader work was completed, the compound was left at room temperature for about 24 hours to mature, and then 2 parts by weight of the peroxide cross-linker and 0.5 parts by weight of the co-cross-linker were additionally mixed in an open roll mill and dispersed uniformly for 5 minutes to prepare a 5 mm sheet-like compound. . The sheet-like compound prepared in this way was put into a mold manufactured according to the test standard, and then molded for about 10 minutes under press conditions of 170°C and 150 kgf/cm ² to prepare a specimen.

<Comparative Example 2>

Based on 100 parts by weight of the rubber base consisting of 80 parts by weight of EPDM rubber and 20 parts by weight of silicone rubber, 100 parts by weight of carbon black, 30 parts by weight of light calcium carbonate with a particle size of 2 ㎛, paraffin structure content of 63%, and aromatic structure content of 5%. 40 parts by weight of in-process oil, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 2 parts by weight of polyethylene glycol, and 1.5 parts by weight of an anti-aging agent were kneaded at 100°C for about 10 minutes using a compound kneader. Manufactured. After the kneader work was completed, the compound was left at room temperature for about 24 hours to mature, and then 2 parts by weight of the peroxide cross-linker and 0.5 parts by weight of the co-cross-linker were additionally mixed in an open roll mill and dispersed uniformly for 5 minutes to prepare a 5 mm sheet-like compound. . The sheet-like compound prepared in this way was put into a mold manufactured according to the test standard, and then molded for about 10 minutes under press conditions of 170°C and 150 kgf/cm ² to prepare a specimen.

As described above, Examples 1 to 3 produced specimens composed of radiator hose compositions by varying the components of the rubber base, Comparative Example 1 used only EPDM rubber as the rubber base, and Comparative Example 2 used EPDM rubber as the rubber base. 80 parts by weight and 20 parts by weight of silicone rubber were used, and Comparative Examples 1 and 2 had the same contents of zinc oxide, stearic acid, polyethylene glycol, anti-aging agent, peroxide cross-linking agent, and co-cross-linking agent as those of Examples 1 to 3, but modified EPDM was used. A specimen consisting of a radiator hose composition was prepared by varying the ingredients, such as not adding any, and the specific formulation is summarized in Table 1 below. However, the unit is parts by weight.

Example Comparative example One 2 3 One 2 EPDM rubber 95 85 95 100 80 silicone rubber 5 15 5 - 20 modified EPDM 3 5 3 - - carbon black 100 100 100 120 100 Calcium carbonate ¹⁾ - - - - 30 Calcium carbonate ²⁾ 30 30 50 - - Process oil ¹⁾ - - - 40 40 Process oil ²⁾ 40 40 50 - - zinc oxide 5 5 5 5 5 stearic acid 2 2 2 2 2 polyethylene glycol 2 2 2 2 2 anti-aging agent 1.5 1.5 1.5 1.5 1.5 peroxide crosslinking agent 2 2 2 2 2 public dating 0.5 0.5 0.5 0.5 0.5 Calcium carbonate ¹⁾ : Light calcium carbonate with particle size of 2 ㎛
Calcium carbonate ²⁾ : Ultrafine calcium carbonate with a particle size of 0.1 ㎛ or less and surface treated with fatty acid.
Process oil ¹⁾ : Process oil with a paraffin structure content of 63% and an aromatic structure content of 5% (Michang Petrochemical, P-3)
Process oil ²⁾ : Process oil with a paraffin structure content of 70% and an aromatic structure content of 0%.

<Test Example 1>

In this test example, the basic physical properties and accelerated aging tests of Examples 1 to 3 and Comparative Examples 1 and 3 were analyzed. In relation to this, the accelerated aging test was performed by subjecting the manufactured specimens to accelerated aging at a temperature of 150 ± 1°C for 168 hours and then measuring the changes in characteristic values before and after accelerated aging. The results are shown in Table 2 below. .

Example Comparative example One 2 3 One 2 Properties Hardness
(Hs) 67 67 68 68 67 tensile strength
(MPa) 11.6 10.9 11.3 10.5 8.9 elongation rate
(%) 360 330 350 320 270 Promotion
Aging
test Hardness change
(Hs) +8 +5 +7 +13 +7 Tensile strength change rate
(%) -29.8 -24.6 -26.7 -43.5 -30.7 Rate of change in elongation
(%) -30.2 -28.9 -31.0 -50.8 -37.5

According to the basic physical properties and accelerated aging test results in Table 1, Examples 1 to 3 are overall superior to Comparative Examples 1 and 2, and Comparative Example 1 showed the lowest value in the accelerated aging test. In Comparative Example 2, silicone rubber was applied and the accelerated aging test results were improved compared to Comparative Example 1, but the basic physical properties were low because EPDM rubber and silicone rubber did not mix well.

In summary, the present invention relates to 100 parts by weight of a rubber base consisting of 80 to 95 parts by weight of EPDM (ethylene propylene diene monomer) rubber and 5 to 20 parts by weight of silicone rubber, 3 to 10 parts by weight of modified EPDM, and 100 to 120 parts by weight of carbon black. 10 to 50 parts by weight of calcium carbonate with a particle size of 0.1 ㎛ or less and surface-treated with fatty acid, and 30 to 50 parts by weight of hydrocarbon-based process oil with a paraffin content of 70% or more.

According to these characteristics, the interface between EPDM rubber and silicone rubber is controlled to enhance compatibility, thereby forming a rubber composition that can secure high temperature durability above 150 ℃, and it is expected that it can be used in automobile radiator hoses.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for explanation, and the scope of the technical idea of the present invention is not limited by these examples. The scope of protection of the present invention should be interpreted in accordance with the scope of the patent claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

Claims (3)

With respect to 100 parts by weight of a rubber base consisting of 80 to 95 parts by weight of EPDM (ethylene propylene diene monomer) rubber and 5 to 20 parts by weight of silicone rubber,
Characterized in that it is formed by comprising 3 to 10 parts by weight of a compatibilizer, 100 to 120 parts by weight of carbon black, 10 to 50 parts by weight of calcium carbonate, and 30 to 50 parts by weight of a hydrocarbon-based process oil with a paraffin structure content of 70% or more. Radiator hose composition for use. According to claim 1,
A radiator hose composition for automobiles, wherein the calcium carbonate has a particle size of 0.1 ㎛ or less and is surface-treated with fatty acid. According to claim 1,
The compatibilizer is a radiator hose composition for automobiles, characterized in that modified EPDM (modified EPDM).