KR20120095616A - Rubber hose composition, rubber hose and method for manufacturing rubber hose using the same - Google Patents

Abstract

PURPOSE: A rubber hose composition is provided to have a cheap unit cost, to be able to be used in high temperatures about 180°C, and to minimize degradation of mechanical property. CONSTITUTION: A rubber hose composition comprises: base rubber comprising ethylene acryl-based elastomer; filler comprising silica; a cross-linking agent; and a crosslinking aid. On the basis of 100.0 parts by weight of the base rubber, 10-30 parts by weight of the silica is comprised. The ethylene acryl-based elastomer is a terpolymer having acryl-crosslinkable sites capable of crosslinking with diamine based compound. The ethylene acryl-based elastomer has a Mooney viscosity ML(1+4) at 100 °C is 25-35.

Description

Rubber hose composition, rubber hose using the same and manufacturing method therefor {RUBBER HOSE COMPOSITION, RUBBER HOSE AND METHOD FOR MANUFACTURING RUBBER HOSE USING THE SAME}

The present invention relates to a rubber hose composition, a rubber hose using the same, and a method for manufacturing the same, more specifically, can be supplied at a low price, heat-resistant rubber hose composition, which can minimize the mechanical properties after aging, rubber using the same It relates to a hose and a method of manufacturing the same.

A rubber hose for transporting a fluid (liquid or gas) requires physical properties such as heat resistance, pressure resistance and oil resistance as well as ease and unit price (price) in the manufacturing process. At this time, if the required physical properties are not sufficiently considered, it may lead to a failure or an accident of the equipment, and the continuous maintenance work of these equipment is required. Accordingly, efforts have been made to manufacture rubber hoses having improved physical properties. In addition, efforts are being made to secure price competitiveness along with improving properties.

Rubber hoses are widely used, for example, in turbochargers, intercoolers, and the like of vehicles (cars, etc.). In general, rubber hoses are prepared by extruding a composition comprising a base rubber, a filler, a crosslinking agent and a crosslinking aid as essential components. Recently, as the turbo charger is developed as a high specification, the air compression ratio is increasing. As a result, the generated heat is high and a high heat resistance rubber hose is required. In the case where the heat resistance is weak, mechanical properties such as tensile strength and elongation rate may be degraded due to heat aging, which may cause a failure or an accident of the equipment as described above.

Conventionally, in manufacturing a rubber hose, a technique using fluorine-based (FKM) rubber or silicone-based (VMQ) rubber for heat resistance has been proposed. For example, International Patent Publication No. WO2003 / 098088 discloses a rubber hose for an intercooler using a fluororubber composition as an inner layer and a silicone rubber composition as an outer layer, and Japanese Patent Laid-Open No. 2001-123840 discloses a turbocharger ( Piping structure consisting of silicon hose is shown in the engine of turbocharged engine. In addition, the Republic of Korea Patent No. 10-0756748 and Republic of Korea Patent No. 10-0770070 is also shown a rubber hose using a fluororubber composition as the inner layer, the silicone rubber composition as the outer layer.

The fluorine rubber and the silicone rubber are excellent in heat resistance. Deterioration of mechanical properties at high temperature is small. However, fluorine-based or silicone-based rubbers have a problem in that price competitiveness is low due to cost increase to be applied as base rubber because the rubber raw material itself is expensive.

Therefore, there is a demand for a rubber hose having excellent heat resistance while being able to be supplied at a low price. An object of the present invention is to provide a rubber hose composition, a rubber hose using the same and a method for manufacturing the same, which can secure a price competitiveness compared to the conventional high heat resistant rubber and minimize the deterioration of mechanical properties after aging.

As a more specific object, the present invention has an object of providing a rubber hose composition, a rubber hose using the same and a method of manufacturing the same having a low cost, which can be used in a high temperature environment of about 180 ℃.

The present invention to achieve the above object,

Base rubbers including ethylene acrylic elastomers;

Fillers including silica;

A crosslinking agent; And

Including a crosslinking aid,

The silica provides a rubber hose composition containing 10 to 30 parts by weight based on 100 parts by weight of the base rubber.

At this time, the ethylene acrylic elastomer is preferably a terpolymer having an acrylic crosslinking site capable of crosslinking with a diamine compound. In addition, it is preferable that the said ethylene acryl-type elastic polymer has the pattern viscosity ML (1 + 4) value in 25-35 at 100 degreeC.

Further, according to the present invention,

Rubber inner layer;

Fibrous layer; And

Including a rubber outer layer,

At least one selected from the rubber inner layer and the rubber outer layer provides a rubber hose comprising the rubber hose composition according to the present invention.

In addition, the present invention,

(I) processing the rubber hose composition onto a strip to prepare a rubber strip for forming a rubber inner layer and a rubber outer layer;

(II) extruding the prepared rubber strip to form a rubber inner layer having a hollow;

(III) forming a fibrous layer on the rubber inner layer; And

(IV) using the prepared rubber strip, forming a rubber outer layer on the fiber layer,

At least one selected from the rubber inner layer and the rubber outer layer provides a method of manufacturing a rubber hose using a rubber strip of the rubber hose composition according to the present invention.

At this time, the (I) step,

(a) a first kneading step of kneading a base rubber including an ethylene acrylic elastomer and a filler including silica, wherein the silica is kneaded to 10 to 30 parts by weight based on 100 parts by weight of the base rubber;

(b) a second kneading step of kneading by adding a crosslinking agent and a crosslinking aid to the first kneaded compound; And

(c) The second kneaded compound is preferably prepared in a strip form, and then the aging step of aging at room temperature is preferable.

According to the present invention, an ethylene acrylic elastomer is used as the base rubber, so that the price competitiveness is secured compared to the conventional fluorine or silicone rubber, and the heat resistance is appropriate. Particularly, according to the present invention, silica is included as a filler, and the silica is formed in an optimal content, thereby minimizing the mechanical property degradation caused by deterioration (aging due to high heat). Accordingly, the present invention can supply a rubber hose that can be used in a high temperature environment (for example, a high temperature environment of about 180 ℃) at a low price.

1 is a partially cutaway perspective view of a rubber hose in accordance with an exemplary form of the present invention.

Hereinafter, the present invention will be described in detail.

The rubber hose composition according to the present invention comprises a base rubber, a filler, a crosslinking aid and a crosslinking agent. The rubber hose composition according to the present invention may further include additives such as antioxidants in addition to the above components.

The base rubber includes at least an ethylene acrylic rubber (AEM). The base rubber may be specifically composed of an ethylene acrylic elastomer or may further include other rubber components in addition to the ethylene acrylic elastomer. For example, the base rubber may further comprise, in addition to the ethylene acrylic elastomer, a small amount of one or more rubber components selected from fluorine and silicone rubbers. Although not particularly limited, the ethylene acrylic elastomer may be included in an amount of 80 to 100 parts by weight based on 100 parts by weight of the base rubber. Although the said ethylene acryl-type elastomer is somewhat lower than fluorine-type and silicone type rubber in heat resistance, it is excellent in heat resistance compared with other rubber | gum, and also excellent in pressure resistance and oil resistance.

The ethylene acrylic elastomer is preferably a terpolymer having an acrylic crosslinking site capable of crosslinking with a diamine compound. As the ethylene acrylic elastomer, it is particularly preferable to use a ternary copolymer based on an ethylene monomer and an acrylate monomer and a small amount of an acrylic crosslinking site monomer. The ethylene acrylic elastomer may be a terpolymer having a carboxyl group in the side chain. In this case, the ethylene acrylic elastomer may be crosslinked (vulcanized) or cured by a crosslinking reaction of the functional group of the acrylic crosslinking site monomer and the crosslinking agent. As a crosslinking agent of an ethylene acrylic elastomer, a diamine compound, a peroxide compound, or the like can be used, but the crosslinking agent is preferably a diamine compound. Specifically, according to a preferred embodiment of the present invention, a terpolymer having an acrylic crosslinking site capable of crosslinking with a diamine-based compound (hexamethylene diamine, etc.) is used as the ethylene acrylic elastomer, and a diamine-based compound is used as the crosslinking agent. In this case, the crosslinking (curing) rate is slow, but there is no scorched phenomenon caused by curing too fast, and physical properties such as heat resistance and pressure resistance may be improved.

In addition, the ethylene acrylic elastomer has a Molecular Viscosity (Mooney viscosity) ML (1 + 4) value of about 20 to 40 (at 100 ° C). Specifically, when measuring the viscosity using a pattern viscometer at 100 ° C, the pattern viscosity ML (1 + 4) value measured after 4 minutes of the rotor startup of the viscometer at 1 minute of preheating is about 20 to 40 poise. good. At this time, if the ML (1 + 4) value is too low as less than 20 in terms of crosslinking rate and strength is not preferable, if too high above 40 may be undesirable in workability. As for the said ethylene acrylic elastomer, it is more preferable that the pattern viscosity ML (1 + 4) value in 100 degreeC is about 25-35.

The ethylene acrylic elastomer, which is a terpolymer having an acrylic crosslinking site capable of crosslinking with a diamine compound, and / or a pattern viscosity ML (1 + 4) at 100 ° C. of 20 to 40 (preferably 25 to 35) can be purchased on the market. As such an ethylene acrylic elastomer, a Vamac series manufactured by Dupont performance elastomer can be purchased and used.

The filler is used for reinforcing physical properties of the rubber hose, and the filler includes at least silica (SiO ₂ ). At this time, the silica is contained in 10 to 30 parts by weight based on 100 parts by weight of the base rubber, preferably 100 parts by weight of ethylene acrylic elastomer. The content range of such silica serves as an important factor for achieving the object of the present invention. That is, the rubber hose may be inferior in mechanical properties such as tensile strength and elongation rate due to heat aging under high temperature environment, silica is formulated in the appropriate content of the above range, excellent mechanical properties at high temperature as well as mechanical properties at room temperature Have it. At this time, when the content of silica is less than 10 parts by weight, the heat resistance reinforcing ability is weak, the effect of minimizing mechanical property degradation during aging by heat. That is, if it is less than 10 parts by weight, mechanical degradation such as tensile strength and elongation at the time of deterioration rapidly decreases. In addition, when the content of silica exceeds 30 parts by weight, the mechanical properties at room temperature are reduced due to excessive use of silica, and the effect of reducing the change in mechanical properties at the time of aging is not so high compared to the input amount, but may be further lowered. For this reason, the silica is included in 10 to 30 parts by weight based on 100 parts by weight of the base rubber according to the present invention.

In addition, the silica may have an average particle size of 0.05 to 1.0 micrometer (μm) for uniform dispersibility with the base rubber. The silica may more preferably have an average particle size of 0.1 to 0.2 µm, and more specifically, an average particle distribution of about 0.15 µm. In addition, the silica may have a surface area of 1 to 200 m 2 / g, preferably 10 to 30 m 2 / g, and more preferably spherical particles having a specific surface area of 20 m 2 / g.

The filler includes at least silica as described above, but may further include other fillers in addition to silica. For example, the filler may further include one or more selected from the group consisting of carbon black, calcium carbonate, calcium hydroxide, magnesium hydroxide, titanium oxide, talc, clay, calcium silicate, and the like, in addition to silica. And these added filler is not particularly limited, but may be included in 30 to 100 parts by weight, preferably 50 to 80 parts by weight with respect to 100 parts by weight of the base rubber. In addition, the carbon black may use one or a combination thereof selected from a fast extrusion furnace (FEF) of the furnace black and a medium thermal (MT) of the thermal black. According to a specific embodiment, the filler may be used by mixing silica and carbon black. As a more specific example, the filler may be used by mixing silica, fast extrusion furnace (FEF) and medium thermal (MT). At this time, silica is included in the content range of 10 to 30 parts by weight based on 100 parts by weight of the base rubber, carbon black (FEF + MT) may be included in 30 to 100 parts by weight (preferably 50 to 80 parts by weight). have.

Any crosslinking agent may be used as long as it can crosslink the base rubber (ethylene acrylic elastomer). The crosslinking agent may be used, for example, at least one selected from a peroxide compound and a diamine compound. At this time, the peroxide-based compound (peroxide) is dicumyl peroxide (DCP), di- (2, 4-dichlorobenzoyl) -peroxide, 2, 5-di-methyl-2, 5-di- (turcher) Examples include li-butylperoxy) -hexane, 1,1-bis (tertiary-butylperoxy) -3,3,5-trimethylcyclohexane and bis (tertiary-butylperoxy isopropyl) benzene. Examples of the diamine-based compound include ethylene diamine-based, propylene diamine-based, hexamethylene diamine-based, tolylene diamine-based and xylene diamine-based. According to a preferred embodiment of the present invention, the crosslinking agent may be selected from diamine-based compounds such as hexamethylene diamine-based.

At this time, when using a diamine-based compound such as hexamethylene diamine-based as a crosslinking agent as described above, when reacting with the ethylene acrylic elastomer (a terpolymer having an acrylic crosslinking site capable of crosslinking with the diamine-based compound) Peroxide) is slower than the case of using a peroxide, but there is no scorched phenomenon caused by curing too fast, and the physical properties such as heat resistance and pressure resistance may be improved.

The crosslinking agent is not particularly limited, but may be included in an amount of 0.2 to 5 parts by weight based on 100 parts by weight of the base rubber, and preferably 1 to 2 parts by weight based on 100 parts by weight of the base rubber. At this time, if the content of the crosslinking agent is too small, the crosslinking speed may proceed too slowly. If the content is too high, the crosslinking speed may be too fast, and thus the adhesive force with the fiber layer 20 (see FIG. 1) may be lowered when the rubber hose is manufactured.

The crosslinking aid is not particularly limited as long as it can promote crosslinking of the base rubber (ethylene acrylic elastomer). For example, the crosslinking aid may be one or more selected from cyanurate-based compounds and diphenyl guanidine-based compounds. In this case, the cyanurate compound may include triaryl isocyanurate, triaryl cyanurate, trimethyl isocyanurate, and the like, and the diphenyl guanidine compound may be diphenyl guanidine (DPG). Etc. can be mentioned. According to a preferred embodiment, the crosslinking aid may be selected from diphenyl guanidine-based compounds. Thus, when using a diphenyl guanidine type compound as a crosslinking adjuvant, the effective crosslinking promotion of the said ethylene acrylic elastomer can be aimed at.

The crosslinking aid is not particularly limited, but may be included in an amount of 1 to 10 parts by weight based on 100 parts by weight of the base rubber, and preferably 4 to 6 parts by weight based on 100 parts by weight of the base rubber. At this time, if the content of the crosslinking aid is too small, the crosslinking density is low, for example, the mechanical properties such as modulus, hardness, etc. may be lowered. If the content is too high, the workability is poor when the rubber hose is manufactured, and the fiber layer 20 (see FIG. 1). The adhesive strength with may be reduced.

In addition, the rubber hose composition according to the present invention includes at least a base rubber, a filler, a crosslinking agent and a crosslinking aid as described above, may optionally further include an additive. The additive may be used, for example, one or more selected from antioxidants, mold release agents, plasticizers (softeners) and the like. The rubber hose composition according to the present invention preferably further comprises an antioxidant as an additive. At this time, the antioxidant is not particularly limited as long as it can prevent oxidation of the rubber hose composition, according to a preferred embodiment the antioxidant is preferably selected from diphenylamine-based compounds. The diphenylamine compound is preferably used in the present invention to effectively prevent oxidation of the ethylene acrylic elastomer.

In addition, the antioxidant (diphenylamine compound) is not particularly limited, but may be included in 0.5 to 8 parts by weight based on 100 parts by weight of the base rubber, preferably 2 to 3 parts by weight based on 100 parts by weight of the base rubber. It is good to be included. At this time, if the content of the antioxidant is too small, the antioxidant effect according to its content is insignificant, and if the content is too much, the synergistic effect due to the excessive content is not so high and may be undesirable in terms of price.

The rubber hose composition according to the present invention described above is used for the manufacture of a rubber hose. For example, when the rubber hose includes a rubber inner layer 10 (see FIG. 1) and a rubber outer layer 30 (see FIG. 1), the rubber hose composition according to the present invention may be provided with the rubber inner layer 10 and the rubber outer layer 30. Can be used for the production of one or more selected from. As described above, the rubber hose composition according to the present invention uses an ethylene acrylic elastomer as the base rubber, thereby securing a price competitiveness compared to conventional fluorine or silicone rubber. In addition, silica is included as a filler, and the silica is formulated to an optimal content (10 to 30 parts by weight) to minimize mechanical degradation caused by deterioration (aging due to high heat). Accordingly, a rubber hose which can be used in a high temperature environment, for example, a high temperature environment of about 180 ° C., can be supplied at a low price.

Hereinafter, a rubber hose according to the present invention will be described with reference to FIG. 1. 1 is a partial cutaway perspective view of a rubber hose according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the rubber hose according to the present invention includes a rubber inner layer 10, a fiber layer 20 formed on the rubber inner layer 10, and a rubber outer layer 30 formed on the fiber layer 20. Include. At this time, at least one selected from the rubber inner layer 10 and the rubber outer layer 30 includes the rubber hose composition according to the present invention. Specifically, at least one selected from the rubber inner layer 10 and the rubber outer layer 30 is composed of a rubber hose composition according to the present invention as described above, or added to the rubber hose composition according to the present invention as described above. The components are formed from the more mixed mixture. The additional component is not particularly limited, and examples thereof include a release agent, a metal oxide, and the like, which are usually added to a rubber hose.

The fibrous layer 20 is selected from textile or non-textile fabricated fiber yarns. The fiber layer 20 is preferably made of a braided layer formed by coating a braid of fiber yarn on the rubber inner layer 10 as a woven fabric. Such a braided layer is preferable in the present invention in view of physical properties such as pressure resistance. The fibers constituting the fiber layer 20 may be used at least one selected from natural fibers and synthetic fibers, for example polyethylene fibers, polyacrylate fibers, paraphenylene terephthalate fibers, metaphenylene terephthalate fibers, para Any one selected from phenylene-2,6-benzobisoxazole fibers, carbon fibers, alumina fibers, and silicon carbide fibers, or two or more blended fibers selected from these may be used.

In addition, the rubber hose according to the present invention includes at least the rubber inner layer 10, the fibrous layer 20 and the rubber outer layer 30, in addition to these may further include a separate layer. For example, a coating layer (not shown) for chemical resistance or the like may be formed on the inner surface of the rubber inner layer 10 and / or the outer surface of the rubber outer layer 30. In addition, a separate rubber layer (not shown) may be further formed between the rubber inner layer 10 and the fiber layer 20, or between the fiber layer 20 and the rubber outer layer 30. At this time, the rubber layer may be formed from the rubber hose composition of the present invention as described above, or may be formed from another rubber composition.

The rubber hose according to the present invention can be produced by extrusion, but the production method is not particularly limited. Preferably it can be prepared through the production method according to the invention described below. Hereinafter, a method of manufacturing a rubber hose according to the present invention.

Method for producing a rubber hose according to the invention, (I) preparing a rubber strip; (II) forming a rubber inner layer 10; (III) forming a fibrous layer 20; And (IV) forming the rubber outer layer 30. Each step is described as follows.

(Ⅰ) preparing the rubber strip

The rubber hose composition according to the present invention is processed into strips to prepare rubber strips for forming the rubber inner layer 10 and / or the rubber outer layer 30, respectively.

In this case, the present step (I) of preparing a rubber strip, (a) kneading a base rubber containing an ethylene acrylic elastomer, and a filler containing silica, wherein the silica is 10 to 30 parts by weight based on 100 parts by weight of the base rubber A first kneading step (first compound production) for kneading to be a weight part; (b) a second kneading step (second compound preparation) of kneading by adding a crosslinking agent and a crosslinking aid to the first kneaded compound; And (c) preparing the second kneaded compound (second compound) in a strip form and then aging step of ripening at room temperature. These steps (a), (b) and (c) are continuous. And additives such as antioxidants may be added in one or more processes selected from the (a) process and (b) process.

The first kneading of the step (a) can be carried out, for example, using an internal mixer at room temperature, and the second kneading of the step (b) is, for example, an open roll at room temperature. You can proceed using a roll-mill.

In addition, the strip in the step (c) may be manufactured to have a width (length) of 5 to 80mm, a thickness (diameter) of 1 to 50mm, for example, a width (length) of 40 to 50mm, thickness ( Diameter) 10 to 20 mm, but is not limited thereto. In addition, a release agent may be attached (coated) so that the strips do not adhere or entangle with each other. The strip is then aged after the release agent is attached (coated), which may proceed for at least 10 hours, preferably at least 24 hours at room temperature.

(II) forming the rubber inner layer 10

The rubber inner layer 10 having a hollow is formed by using the prepared rubber strip. The rubber inner layer 10 may be extruded, for example, by inserting a rubber strip into an extruder maintained at an appropriate temperature to form a hollow in the longitudinal direction.

(Ⅲ) Fibrous layer 20  Forming steps

The fiber layer 20 is formed on the rubber inner layer 10. The fiber layer 20 may be formed by laminating a woven or nonwoven fabric on the rubber inner layer 10. Preferably, the braided material (fabric) is coated on the rubber inner layer 10 so that the fiber layer 20 becomes a braided layer. For example, it may be formed by coating the braid woven with a fiber yarn, such as polyamide-based so as to be wrapped on the rubber inner layer (10). As another example, the fiber layer 20 may be formed by spirally winding the fiber yarn on the rubber inner layer 10. At this time, the adhesion between the rubber inner layer 10 and the fibrous layer 20 may be achieved by the composition constituting the rubber inner layer 10, that is, the compound melt on the strip, or by a separate adhesive.

(IV) forming the rubber outer layer 30

The rubber outer layer 30 is formed on the fiber layer 20. The rubber outer layer 30 is formed by coating the rubber strip prepared in step (I) on the fiber layer 20. The rubber outer layer 30 may be formed through extrusion, for example by injecting a rubber strip into an extruder maintained at a suitable temperature. At this time, the adhesion between the fibrous layer 20 and the rubber outer layer 30 may be achieved by the composition constituting the rubber outer layer 30, that is, the compound melt on the strip, or by a separate adhesive.

When the extrusion is completed from the rubber inner layer 10 to the rubber outer layer 30 through the steps (I) to (IV) as described above, after the release agent is applied to the surface of the extrudate as usual before crosslinking proceeds It may be inserted into a cylindrical mandrel to maintain a constant shape. Thereafter, the pressure is, for example, 1 to 15 atm, the crosslinking temperature is, for example, 80 to 250 ° C, and the crosslinking time is, for example, 2 minutes to 10 hours, and then the crosslinked rubber hose is removed from the mandrel. Desorption can complete the manufacture.

The rubber hose according to the present invention described above can be used for transporting a fluid (liquid or gas) in various industrial fields. The rubber hose according to the present invention may be used, for example, a rubber hose for a vehicle. For example, the rubber hose according to the present invention may be usefully used as a heat resistant rubber hose for frequent exposure to high temperature air, such as a turbo charger or an intercooler of a vehicle.

As described above, the rubber hose according to the present invention contains an ethylene acrylic elastomer as a main component, and silica is contained in an appropriate amount as a filler, so that the deterioration of mechanical properties is minimized even in a high temperature environment, for example, a high temperature environment of about 180 ° C. Can be used stably. In addition, it does not use expensive heat-resistant rubber such as fluorine-based or silicon-based, it is possible to secure a price competitiveness according to cost reduction.

Hereinafter, embodiments of the present invention will be exemplified. The following examples are merely provided to aid the understanding of the present invention, whereby the technical scope of the present invention is not limited. The following Examples and Comparative Examples illustrate experimental examples for determining the change in mechanical properties according to the content of silica among the various experimental examples for the implementation of the present invention.

[Examples and Comparative Examples]

To the rubber hose composition was prepared as follows in the component and content as shown in Table 1.

First, the ethylene acrylic elastomer (ML (1 + 4) value: 30 at 100 ° C.) and the filler (silica + carbon black) were first kneaded at room temperature through an internal mixer, and then the crosslinking agent was After addition of the crosslinking aid, the mixture was second kneaded at room temperature through an open roll-mill. The compounding ratio of the components according to each example and the comparative example is as shown in Table 1 below. At this time, as shown in the following [Table 1], the content of silica was different according to each Example and Comparative Example. As the filler, spherically-shaped SiO ₂ having a mean particle size of about 0.15 μm and an intrinsic surface area of 20 m 2 / g was used. Carbon black was used as a filler by mixing the fast extrusion furnace (FEF) and the medium thermal (MT) in the same weight ratio. After the kneading was completed, the compound was made into a scrap form to have a width of about 45 mm and a thickness of about 15 mm, and then a release agent was applied so as not to adhere to each other, and then aged at room temperature for about 24 hours.

Next, the compound on the aged strip was introduced into an extruder to form a rubber inner layer 10 having a hollow. At this time, the head temperature of the extruder was maintained at about 100 ℃, screw temperature about 60 ℃. The fibrous layer 20 was formed on the extruded rubber inner layer 10. As the fiber layer 20, a braided product of polyamide fiber yarn was used.

Subsequently, the compound on the matured strip was introduced into an extruder to form a rubber outer layer 30 on the fiber layer 20. The temperature of the extruder is as above. The release agent was then applied to the surface of the extrudate and then inserted into a cylindrical mandrel. Then, crosslinking was performed for about 1 hour under conditions of about 5 atm and about 150 ° C. to prepare a rubber hose having a laminated structure as shown in FIG. 1.

           <Component and content of rubber hose composition, unit: parts by weight> Item ingredient Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4
Base
Rubber Ethylene acrylic rubber
ML (1 + 4), 100 ° C .: 30
100
100
100
100
100
100
100

Filler
Carbon black
(FEF + MT) 60 60 60 60 60 60 60 Silica
(spherically-shaped SiO ₂ )
15
20
25
0
5
35
40 Cross-linking agent Hexamethylene diamine
(hexamethylene diamine) 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Crosslinking auxiliary Diphenyl guanidine
(diphenyl guanidine) 4 4 4 4 4 4 4

The mechanical properties of the rubber hose specimens prepared according to the examples and the comparative examples were evaluated as follows.

First, the mechanical properties of the rubber hose specimens prepared were evaluated at room temperature, and then the aging was performed, and then the mechanical properties were evaluated and compared. At this time, the aging was maintained for 168 hours in the oven at 185 ℃, the aging was progressed, and the evaluation items of mechanical properties were the hardness, tensile strength and elongation before (aging) and after aging (185 ℃, 168 hours). These mechanical properties are measured using a universal test machine (UTM), the hardness of which is Shore hardness A type according to ISO 7619-1, and the tensile strength and elongation are 2 or 4 dumbbells according to ISO 37. ) Was measured in the shape type. The measured results are shown in the following [Table 2]. At this time, the mechanical properties after aging in the following [Table 2] is shown as a change amount. In other words, the hardness is shown as a decrease amount, the tensile strength and the elongation rate as a change rate (%, reduction rate).

                <Evaluation of mechanical properties before and after aging> Evaluation items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Before aging
(Room temperature)
Hardness (Hs) 65 68 70 58 61 76 79 Tensile strength (MPpa) 13 14 15 19 18 10 9 Elongation (%) 280 272 265 331 324 200 198 After aging
(185 ℃)
Hardness change (Hs) 8 7 6 20 19 13 12 Tensile Strength Change (%) 15 12 11 36 31 19 18 Elongation rate of change (%) 37 40 48 73 71 56 51

A comparison of the evaluation results shown in [Table 2] is as follows.

First, in Examples 1 to 3 it was found that the hardness at room temperature is high compared with Comparative Examples 1 to 2. And even if the tensile strength and elongation at room temperature is lower than Comparative Examples 1 to 2, it can be seen that this satisfies the basic physical properties required for the rubber hose. In addition, Examples 1 to 3 it can be seen that the mechanical properties change after aging within a stable range. However, in the case of Comparative Examples 1 to 2 it can be seen that the mechanical properties sharply decrease after aging. In addition, it can be seen that Examples 1 to 3 have excellent mechanical properties after aging as well as mechanical properties at room temperature as compared with Comparative Examples 3 to 4.

In particular, when looking at the tensile strength and elongation, in the case of Comparative Examples 1 and 2, the amount of silica is insignificant. Could know. In addition, in the case of Comparative Examples 3 to 4, the dosage of silica was excessive, and the tensile strength and elongation at low temperature were low. .

Therefore, through the above experimental example, it can be seen that the mechanical properties at room temperature according to the silica content, as well as have a significant effect on the mechanical properties after aging in particular, the silica content acts as an important factor for the mechanical properties. In other words, when silica is included in an amount of 10 to 30 parts by weight with respect to 100 parts by weight of the base rubber (ethylene acrylic elastomer) as the optimum content according to the present invention, while maintaining good mechanical properties at room temperature, It was found that physical property degradation can be minimized. In addition, it can be seen that in the content of the above range, stable mechanical properties are maintained at room temperature as well as in a high temperature environment of about 180 ℃.

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

Claims (16)

Base rubbers including ethylene acrylic elastomers;
Fillers including silica;
A crosslinking agent; And
Including a crosslinking aid,
The silica is a rubber hose composition, characterized in that contained in 10 to 30 parts by weight based on 100 parts by weight of the base rubber.
The method of claim 1,
The ethylene acrylic elastomer is a rubber hose composition, characterized in that the terpolymer having an acrylic crosslinking site capable of crosslinking with the diamine compound.
The method of claim 1,
The said ethylene acryl-type elastomer is a rubber hose composition characterized by the pattern viscosity in ML (1 + 4) value 25-35 at 100 degreeC.
The method of claim 1,
Said filler further comprises at least one selected from the group consisting of carbon black, calcium carbonate, calcium hydroxide, magnesium hydroxide, titanium oxide, talc, clay and calcium silicate.
The method of claim 2,
The crosslinking agent is a rubber hose composition, characterized in that selected from diamine-based compounds.
The method of claim 2,
The crosslinking aid is rubber hose composition, characterized in that selected from diphenyl guanidine-based compound.
The method of claim 1,
The silica is a rubber hose composition, characterized in that the average particle size is 0.1 ~ 0.2㎛, the surface area is 10 ~ 30 m 2 / g.
The method of claim 1,
The rubber hose composition further comprises an antioxidant, wherein the antioxidant is rubber hose composition, characterized in that selected from diphenylamine-based compounds.
The method of claim 1,
The crosslinking agent is a rubber hose composition, characterized in that contained in 1 to 2 parts by weight based on 100 parts by weight of the base rubber.
The method of claim 1,
The crosslinking aid is a rubber hose composition, characterized in that included in 4 to 6 parts by weight based on 100 parts by weight of the base rubber.
9. The method of claim 8,
The antioxidant is a rubber hose composition, characterized in that contained in 2 to 3 parts by weight based on 100 parts by weight of the base rubber.
Rubber inner layer;
Fibrous layer; And
Including a rubber outer layer,
At least one selected from the rubber inner layer and the rubber outer layer comprises a rubber hose composition according to any one of claims 1 to 11.
The method of claim 12,
The fiber layer is a rubber hose composition, characterized in that the braided layer formed by coating the braid on the rubber inner layer.
(I) processing the rubber hose composition onto a strip to prepare a rubber strip for forming a rubber inner layer and a rubber outer layer;
(II) extruding the prepared rubber strip to form a rubber inner layer having a hollow;
(III) forming a fibrous layer on the rubber inner layer; And
(IV) using the prepared rubber strip, forming a rubber outer layer on the fiber layer,
At least one selected from the rubber inner layer and the rubber outer layer is a rubber hose manufacturing method, characterized in that using the rubber strip processing the rubber hose composition according to any one of claims 1 to 11.
15. The method of claim 14,
In step (I),
(a) a first kneading step of kneading a base rubber including an ethylene acrylic elastomer and a filler including silica, wherein the silica is kneaded to 10 to 30 parts by weight based on 100 parts by weight of the base rubber;
(b) a second kneading step of kneading by adding a crosslinking agent and a crosslinking aid to the first kneaded compound; And
(c) a method of producing a rubber hose, comprising the step of preparing the second kneaded compound in a strip form and then aging at room temperature.
15. The method of claim 14,
Step (III) is a method of manufacturing a rubber hose, characterized in that for coating the braid on the rubber inner layer, the fiber layer to be a braided layer.

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