KR20200065558A - Thermoplastic elastomer composition for air intake hose, and air intake hose for vehicles - Google Patents

Abstract

An air intake hose of the present invention contains: based on 100 parts by weight of (A) ethylene-propylene-diene rubber, 30 to 80 parts by weight of (B) a polypropylene resin; and 2 to 8 parts by weight of (C) a phenolic crosslinking agent, wherein (A) the ethylene-propylene-diene rubber has 20 to 50 wt% of a unit content derived from a propylene monomer and 8 to 10 wt% of a unit content derived from ethylidene-2-norbornene.

Description

Thermoplastic elastomer composition for air intake hoses and air intake hoses for automobiles {THERMOPLASTIC ELASTOMER COMPOSITION FOR AIR INTAKE HOSE, AND AIR INTAKE HOSE FOR VEHICLES}

The present invention relates to a thermoplastic elastomer composition for an air intake hose and an air intake hose for automobiles manufactured using the same. More specifically, the present invention is a thermoplastic elastomer composition for an air intake hose that is advantageous for application to the formation of a bellows structure, while implementing high oil resistance and mechanical properties, and having excellent flowability and formability, to an air intake hose for automobiles manufactured using the same. It is about.

An air intake hose mounted on an automobile air intake is an automobile part mounted in an engine room to allow outside air to enter the vehicle engine. As the material for the air intake hose, epichlorohydrin rubber or chlorinated polyethylene rubber, which has excellent oil resistance, has been mainly used.

However, epichlorohydrin rubber is expensive in terms of material cost and there is a problem of corrosion when contacted with metal, and chlorinated polyethylene rubber generates chlorine gas during product molding. This is true.

Due to these problems, in the automobile industry, ethylene-propylene-diene rubber, which has a low cost and does not form a material harmful to workers, was newly introduced, but ethylene produced at a conventional vulcanization ratio -It is difficult to satisfy the oil resistance performance required by the air intake hose with the propylene-diene monomer rubber composition. In addition, in the case of ethylene-propylene-diene rubber, recycling is not possible, and since the process is vulcanized during manufacturing, the time required for the process is long and the efficiency is low.

Therefore, in recent years, as the weight of automobiles increases and environmental demands increase, there is an increasing demand for a thermoplastic elastomer composition that is excellent in oil resistance as a material for an air intake hose, has a low specific gravity, and is lightweight, and is environmentally friendly and recyclable. .

The background technology of the present invention is described in Korean Patent Registration No. 1504940.

One object of the present invention is to provide a thermoplastic elastomer composition for an air intake hose that is superior in light weight compared to a conventional rubber material, and can implement high oil resistance.

Another object of the present invention is to provide a thermoplastic elastomer composition for an air intake hose that is capable of realizing excellent compression permanent shrinkage by improving permanent deformation performance compared to a conventional rubber material.

Another object of the present invention is to provide an elastic composition for an automobile air intake hose capable of omitting a vulcanization process.

Another object of the present invention is to provide an air intake hose for automobiles formed from the above-described elastic composition for an automobile air intake hose.

The above and other objects of the present invention can be achieved by the present invention described below.

1. One embodiment of the present invention (A) with respect to 100 parts by weight of ethylene-propylene-diene rubber, (B) 30 parts by weight to 80 parts by weight of polypropylene resin; And (C) 2 to 8 parts by weight of a phenolic crosslinking agent; Including, (A) The ethylene-propylene-diene rubber is air having a unit content derived from propylene monomer of 20% to 50% by weight, and a unit content derived from ethylidene-2-norbornene of 8% to 10% by weight. It relates to a thermoplastic elastomer composition for an intake hose.

2. In the above 1 embodiment, the thermoplastic elastomer composition for the air intake hose is based on 100 parts by weight of the (A) ethylene-propylene-diene rubber, (D) 100 parts by weight to 200 parts by weight of paraffin oil; (E) 30 parts by weight to 80 parts by weight of an inorganic filler; And (F) 0.1 to 5 parts by weight of a crosslinking activator; It may be to include one or more of.

3. In the above 1-2 embodiments, (A) the ethylene-propylene-diene rubber may have a ML1+4 Mooney viscosity at 125°C of 20 MU to 100 MU.

4. In the above 1 to 3 embodiments, the (A) ethylene-propylene-diene rubber may include impregnated oil in an amount of 50 phr to 100 phr.

5. In the above 1-4 embodiments, the polypropylene resin (B) has a heat deflection temperature of 100°C to 150°C, a softening point of the Vickett of 135°C to 175°C, and a melt index of 0.5 g/10min to 1.5 g/ 10min, and may have a density of 0.6 g/cm ³ to 1.2 g/cm ³ .

6. In the above 1-5 embodiments, the (E) inorganic filler is at least one of talc, clay, calcium carbonate, wollastonite, calcium sulfate, magnesium oxide, calcium stearate, mica, calcium silicate, and carbon black. It may be included.

7. In the above 1 to 6 embodiments, the (F) crosslinking active agent may include one or more of zinc oxide, tin chloride and zinc stearate.

8. Another embodiment of the present invention relates to an air intake hose for automobiles formed by dynamic crosslinking of the thermoplastic elastomer composition for air intake hoses of the above 1 to 7 embodiments.

9. In the above 8 embodiment, the air intake hose has a hardness gradient value of -22 before and after the oil resistance test for a specimen tested for oil resistance at a temperature of 125±2°C and 70 hours in ASTM NO.3 OIL according to ISO 1817 standard. shore A to 0 shore A, tensile strength change rate (%) is -33% to 0%, elongation change rate (%) is -68% to 0%, 100%M change rate (%) -15% to 0% , And the volume change rate (%) may be 0% to 93%.

The present invention is excellent in light weight compared to the conventional rubber material, can implement a high oil resistance, the permanent deformation performance is improved compared to the conventional rubber material, it is possible to implement an excellent compression permanent reduction rate, the vehicle is possible to omit the vulcanization process The elastic composition for an air intake hose and the effect of providing an air intake hose for automobiles manufactured using the same are realized.

1 is a view showing an air intake hose for a vehicle according to an example of the present invention.

In the present specification, "a to b" in "a to b" representing a numerical range is defined as'≥ a and ≤ b'.

One embodiment of the present invention (A) with respect to 100 parts by weight of ethylene-propylene-diene rubber, (B) 30 parts by weight to 80 parts by weight of polypropylene resin; And (C) 2 to 8 parts by weight of a phenolic crosslinking agent; Including, (A) The ethylene-propylene-diene rubber is air having a unit content derived from propylene monomer of 20% to 50% by weight, and a unit content derived from ethylidene-2-norbornene of 8% to 10% by weight. It relates to a thermoplastic elastomer composition for an intake hose.

The present invention is by using a thermoplastic elastomer composition for air intake hose by dynamic crosslinking, excellent light weight compared to the conventional rubber material, high oil resistance can be achieved, the permanent deformation performance is improved compared to the conventional rubber material, excellent compression permanent It is possible to implement a reduction ratio, and implements an effect of providing an elastic composition for an automobile air intake hose capable of omitting a vulcanization process and an automobile air intake hose manufactured using the same.

In addition, the thermoplastic elastomer composition for an air intake hose of the present invention may not contain sulfur due to the dynamic crosslinking properties described above. In this case, it is possible to omit the vulcanization process, thereby reducing production time and production cost, and realizing excellent oil resistance and flowability.

(A) Ethylene-propylene-diene rubber

(A) Ethylene-propylene-diene rubber (EPDM rubber) used in the thermoplastic elastomer composition for an air intake hose of the present invention is (a-1) a unit derived from an ethylene monomer, (a-2) propylene A ternary copolymer of monomer-derived units and (a-3) ethylidene-2-norbornene-derived units, having weather resistance compared to other conventional rubbers, such as natural rubber, styrene-butadiene rubber, chloroprene, nitrile rubber, etc. Excellent ozone resistance and excellent compatibility with polyolefin-based thermoplastic resins.

Since the ethylene-propylene-diene rubber has an unsaturated bond in the side chain, crosslinking is possible even with a phenolic crosslinking agent other than peroxide. Through this, it is possible to reduce the volatile content of the ethylene-propylene-diene rubber.

The ethylene-propylene-diene rubber (a-1) may include 40% to 70% by weight of an ethylene monomer derived unit, specifically 45% to 65% by weight, and more specifically 55% to 65% by weight. have. Within the above range, the ethylene-propylene-diene rubber can further improve the oil resistance, flowability and moldability of the thermoplastic elastomer composition for air intake hoses.

The content of ethylene monomer derived units in the ethylene-propylene-diene rubber can be measured according to ASTM D 3900.

The ethylene-propylene-diene rubber (a-2) uses a propylene monomer-derived unit content of 20% to 50% by weight. When the (a-2) propylene monomer-derived unit content is less than 20% by weight, it is difficult to implement sufficient strength and mechanical properties, and when it exceeds 50% by weight, it is difficult to implement sufficient flowability and formability. In an embodiment, the ethylene-propylene-diene rubber may include (a-2) propylene monomer-derived units in specifically 25% by weight to 45% by weight, more specifically 25% by weight to 35% by weight. Within the above range, the ethylene-propylene-diene rubber can further improve the oil resistance, flowability and moldability of the thermoplastic elastomer composition for air intake hoses.

The ethylene-propylene-diene rubber (a-3) is ethylidene-2-norbornene derived unit content of 8 wt% to 10 wt% is used. When the unit content derived from (a-3) ethylidene-2-norbornene is less than 8% by weight, it is difficult to implement sufficient physical properties, compression permanent shrinkage, and heat resistance, and when it exceeds 10% by weight, sufficient oil resistance and permanent compression line It is difficult to implement the melody. In an embodiment, the ethylene-propylene-diene rubber includes (a-3) ethylidene-2-norbornene monomer-derived units in an amount of 8.5% to 10% by weight, more specifically 8.7% to 10% by weight. can do. Within the above range, the ethylene-propylene-diene rubber can further improve the oil resistance, flowability and moldability of the thermoplastic elastomer composition for air intake hoses.

The content of the unit derived from the ethylidene-2-norbornene monomer in the ethylene-propylene-diene rubber can be measured according to ASTM D 6047.

The (A) ethylene-propylene-diene rubber may have a ML1+4 Mooney viscosity at 125°C of 20 MU to 100 MU, specifically 50 MU to 100 MU, and more specifically 50 MU to 75 MU. . In this case, the ethylene-propylene-diene rubber can further improve the elasticity, mechanical properties, flowability, and moldability of the thermoplastic elastomer composition for air intake hoses.

The Mooney viscosity is measured by ML 1+4 at a temperature of 125° C. using a Mooney viscometer according to ISO 289.

The (A) ethylene-propylene-diene rubber has a weight average molecular weight of 10,000 g/mol to 1,000,000 g/mol, specifically 50,000 g/mol to 800,000 g/mol, and more specifically 50,000 g/mol to 500,000 g/mol. Can be. In this case, the ethylene-propylene-diene rubber can further improve the oil resistance, flowability and moldability of the thermoplastic elastomer composition for air intake hoses.

The (A) ethylene-propylene-diene rubber may include an impregnated oil in an amount of 50 phr to 100 phr, specifically 50 phr to 80 phr or 80 phr to 100 phr. In this case, the ethylene-propylene-diene rubber can further improve the oil resistance, flowability and moldability of the thermoplastic elastomer composition for air intake hoses.

The content of the impregnated oil in the ethylene-propylene-diene rubber can be measured according to ISO 1407 method D.

The (A) ethylene-propylene-diene rubber may have a molecular weight distribution (Mw/Mn) of 1 to 10, specifically 1.5 to 8, and more specifically 1.5 to 6. In this case, the ethylene-propylene-diene rubber can further improve the oil resistance, flowability and moldability of the thermoplastic elastomer composition for air intake hoses.

The (A) ethylene-propylene-diene rubber has a density of 0.6 g/cm ³ to 1.2 g/cm ³ , specifically a density of 0.7 g/cm ³ to 1.1 g/cm ³ , more specifically a density of 0.8 g/cm ³ to 1.0 g/cm ³ . In this case, the ethylene-propylene-diene rubber can further improve the oil resistance, flowability and moldability of the thermoplastic elastomer composition for air intake hoses.

(B) Polypropylene resin

The polypropylene resin (B) used in the thermoplastic elastomer composition for an air intake hose of the present invention is a thermoplastic resin and is dynamically cross-linked with the (A) ethylene-propylene-diene rubber to form a thermoplastic crosslinked elastic body. Through this, the (B) polypropylene resin can improve the impact strength and elastic force of the thermoplastic elastomer composition for an air intake hose together.

The polypropylene resin (B) may be a homopolymer and/or a block polymer. In this case, the polypropylene resin may further improve the impact strength, elasticity, flowability, and formability of the thermoplastic elastomer for air intake hoses.

The polypropylene resin (B) may have a weight average molecular weight of 10,000 g/mol to 1,000,000 g/mol, specifically 50,000 g/mol to 800,000 g/mol, and more specifically 50,000 g/mol to 500,000 g/mol. In this case, the polypropylene resin can further improve the oil resistance, flowability, and moldability of the thermoplastic elastomer composition for an air intake hose.

The weight average molecular weight is a value measured under conditions of 135°C to 145°C using Trichlorobenzene based on the weight average molecular weight measurement standard.

The polypropylene resin (B) may have a heat deflection temperature (HDT) of 100°C to 150°C, specifically 110°C to 140°C, and more specifically 115°C to 135°C. In this case, the polypropylene resin may further improve the impact strength, elasticity, flowability, and formability of the thermoplastic elastomer for air intake hoses.

The heat deflection temperature (HDT) is a value measured under conditions of load 4.6 kgf/cm ² , starting temperature 25° C., ending temperature 150° C., and heating rate 120±10° C./hr according to ASTM D648.

The (B) polypropylene resin may have a Vicat softening temperature (VST) of 135°C to 175°C, specifically 140°C to 170°C, and more specifically 145°C to 165°C. In this case, the polypropylene resin may further improve the impact strength, elasticity, flowability, and formability of the thermoplastic elastomer for air intake hoses.

The Vickert softening point (VST) is a value measured under conditions of load 4.6 kgf/cm ² starting temperature 25° C., ending temperature 150° C., and heating rate 120±10° C./hr according to ASTM D1525.

The melting index (MI) of the polypropylene resin (B) is 0.5 g/10min to 1.5 g/10min, specifically 0.6 g/10min to 1.4 g/10min, more specifically 0.7 g/10min to 1.2 g/ It can be 10min. In this case, the polypropylene resin can improve the impact strength, elasticity, flowability, and moldability of the thermoplastic elastomer for air intake hose to a more excellent range.

The melt index (MI) is a value measured at a load of 2.16 kg at 230° C. according to the evaluation method specified in ASTM D1238 .

The density of the polypropylene resin (B) is 0.6 g/cm ³ to 1.2 g/cm ^3, specifically 0.7 g/cm ³ to 1.1 g/cm ³ , More specifically, it may be 0.8 g/cm ³ to 1.0 g/cm ³ . In this case, the polypropylene resin can improve the impact strength, elasticity, flowability, and moldability of the thermoplastic elastomer for air intake hose to a more excellent range.

The density of the polypropylene resin is a value measured according to the evaluation method specified in ASTM D792.

In the thermoplastic elastomer composition for an air intake hose of the present invention, the polypropylene resin (B) is included in an amount of 30 to 80 parts by weight based on 100 parts by weight of the (A) ethylene-propylene-diene rubber. When the content of the polypropylene resin (B) is less than 30 parts by weight, the mechanical strength is lowered, and when it is more than 80 parts by weight, the impact strength and elasticity are reduced, which makes it difficult to be applied to an air intake hose for automobiles. In an embodiment, the content of the polypropylene resin (B) may be 35 parts by weight to 75 parts by weight, more specifically 40 parts by weight to 70 parts by weight. In this case, the polypropylene resin may further improve the impact strength, elasticity, flowability, and formability of the thermoplastic elastomer for air intake hoses.

(C) Phenolic crosslinking agent

The (C) phenolic crosslinking agent used in the thermoplastic elastomer composition for air intake hoses of the present invention acts on the thermoplastic elastomer composition to dynamically crosslink by a twin-screw extruder or the like to crosslink the soft segment rubber part. May be Through this, the thermoplastic elastomer composition for an air intake hose can implement excellent degree of viscosity and elasticity.

The (C) phenolic crosslinking agent can decompose the unsaturated carbon bond of the ethylene-propylene-diene rubber to perform crosslinking, and unlike the crosslinking reaction using peroxide, a sufficient amount can be used because it does not decompose the polyolefin-based thermoplastic resin.

The (C) phenolic crosslinking agent may be specifically phenolic resin, more specifically dimethylol phenolic resin, halogenated dimethyl phenolic resin, octyl phenolic resin or the like. The phenolic resins of the above examples may be used alone or in combination of two or more. When the phenolic crosslinking agent of this example is used, the degree of crosslinking by dynamic crosslinking of the thermoplastic elastomer composition for air intake hoses can be controlled in a wide range of 10% to 98%.

The (C) phenolic crosslinking agent is contained in 2 parts by weight to 8 parts by weight based on 100 parts by weight of the (A) ethylene-propylene-diene rubber. When the content of the (C) phenolic crosslinking agent is less than 2 parts by weight, a sufficient degree of crosslinking cannot be achieved and mechanical properties may be deteriorated. In addition, when the content of the (C) phenolic crosslinking agent is more than 8 parts by weight, excessive crosslinking occurs during product molding by unreacted crosslinking agent remaining after the reaction, thereby reducing the mechanical properties of the composition, and protruding on the surface of the molded product, Foreign matters such as gels and black spots may be observed, may affect product color, and moldability may be deteriorated by a rapid crosslinking reaction. In an embodiment, the content of the (C) phenolic crosslinking agent may be included in 3 parts by weight to 7 parts by weight, more specifically 4 parts by weight to 6 parts by weight. In this case, the phenolic crosslinking agent can improve the crosslinking degree of the thermoplastic elastomer for the air intake hose, thereby realizing more mechanical properties.

The thermoplastic elastomer composition for an air intake hose of the present invention comprises (A) 100 parts by weight of paraffin oil to 200 parts by weight based on 100 parts by weight of ethylene-propylene-diene rubber; (E) 30 parts by weight to 80 parts by weight of an inorganic filler; And (F) 0.1 to 5 parts by weight of a crosslinking activator; It may be to include one or more of.

(D) Paraffin oil

(D) Paraffin oil used in the thermoplastic elastomer composition for an air intake hose of the present invention acts on the thermoplastic elastomer composition as a process oil, while improving the retention of mechanical properties while realizing the effect of improving flowability and moldability. .

The (D) paraffin oil may have a kinematic viscosity of 40°C from 90 cSt to 150 cSt, specifically 100 cSt to 130 cSt, and more specifically 115 cSt to 125 cSt. In this case, the paraffin oil can be improved to a more excellent range while realizing the mechanical properties of the thermoplastic elastomer for the air intake hose and its retention, flow, and moldability in a balanced manner.

The kinematic viscosity is a value measured at 40°C according to the evaluation method specified in ISO 3104.

The (D) paraffin oil in the thermoplastic elastomer composition for an air intake hose of the present invention may be included in 100 parts by weight to 200 parts by weight based on 100 parts by weight of (A) ethylene-propylene-diene rubber. In an embodiment, the content of paraffin oil (D) may be 115 parts by weight to 175 parts by weight, more specifically 150 parts by weight to 160 parts by weight. In this case, the paraffin oil can be improved to a more excellent range while realizing the mechanical properties of the thermoplastic elastomer for the air intake hose and its retention, flow, and moldability in a balanced manner.

In addition, when the (D) paraffin oil contains the impregnated oil in the (A) ethylene-propylene-diene rubber, the total oil content may be adjusted within the above-mentioned range in consideration of the impregnated oil content. In this case, the elution of paraffin oil is prevented, and the mechanical properties of the thermoplastic elastomer for the air intake hose and its retention, flow, and formability can be realized in a balanced manner and improved to a more excellent range.

(E) inorganic filler

The inorganic filler (E) used in the thermoplastic elastomer composition for an air intake hose of the present invention acts on the thermoplastic elastomer composition, thereby realizing an effect of improving heat resistance and mechanical properties.

Specifically, the inorganic filler (E) may be one or more of talc, clay, calcium carbonate, wollastonite, calcium sulfate, magnesium oxide, calcium stearate, mica, calcium silicate, and carbon black. The inorganic filler of the above example may be used alone or in combination of two or more. In this case, the inorganic filler can improve the heat resistance and mechanical properties of the thermoplastic elastomer for the air intake hose.

More specifically, the inorganic filler (E) may be one or more of kaolin, talc, and clay. In this case, the inorganic filler may improve the heat resistance and mechanical properties of the thermoplastic elastomer for the air intake hose to a more excellent range.

The shape of the inorganic filler (E) is not particularly limited, but may be, for example, spherical, hollow, flake, needle-like, or the like. In this case, the inorganic filler is excellent in dispersibility, it is possible to improve the workability during extrusion and / or injection molding while realizing the heat resistance and mechanical properties of the thermoplastic elastomer for the air intake hose.

The (E) inorganic filler may have an average particle diameter (D50) of 1 μm to 30 μm, 1 μm to 20 μm, and 5 μm to 30 μm. In this case, the inorganic filler is excellent in dispersibility, it is possible to improve the workability during extrusion and / or injection molding while realizing the heat resistance and mechanical properties of the thermoplastic elastomer for the air intake hose.

The average particle diameter (D50) refers to the number average particle diameter of D50 (particle size at a point where the distribution ratio is 50%) measured by a particle size analyzer.

The (E) inorganic filler is not particularly limited, but may be, for example, an organic modified inorganic filler. At this time, if the organic reforming method is not limited, it may be performed according to a general method known in the same technical field. In this case, while lowering the content of the inorganic filler, the heat resistance and mechanical properties of the thermoplastic elastomer for the air intake hose can be realized in a balanced manner, so that the specific gravity can be relatively lowered, and it can be more advantageous in securing light weight.

In the thermoplastic elastomer composition for an air intake hose of the present invention, the inorganic filler (E) may be included in an amount of 30 parts by weight to 80 parts by weight based on 100 parts by weight of (A) ethylene-propylene-diene rubber. In an embodiment, the content of the inorganic filler (E) may be 30 parts by weight to 70 parts by weight, more specifically 35 parts by weight to 60 parts by weight. In this case, the inorganic filler may improve the heat resistance and mechanical properties of the thermoplastic elastomer for the air intake hose to a more excellent range.

(F) Crosslinking activator

The crosslinking active agent (F) used in the thermoplastic elastomer composition for an air intake hose of the present invention can act on the thermoplastic elastomer composition to increase the crosslinking reaction rate.

The (F) crosslinking activator may include one or more of a metal oxide, a metal halide, and an organic metal compound. When the crosslinking activator of this example is used, the degree of crosslinking by dynamic crosslinking of the thermoplastic elastomer composition for an air intake hose can be controlled in a wide range of 10% to 98%.

Specifically, the metal oxide, metal halide or organometallic compound containing one or more metals among Mg-containing, Pb-containing, Sn-containing, Zn-containing and Cu-containing (F) crosslinking active agents may be used, and more specifically, Examples of the zinc oxide (ZnO), tin chloride (SnCl ₂ ), zinc stearate (Zinc stearate). When the crosslinking activator of this example is used, physical properties can be further improved while controlling the degree of crosslinking by dynamic crosslinking of the thermoplastic elastomer composition for an air intake hose to a wide range of 10% to 98%.

The (F) crosslinking active agent in the thermoplastic elastomer composition for an air intake hose of the present invention may be included in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the (A) ethylene-propylene-diene rubber. In an embodiment, the content of the cross-linking activator (F) may be included in 0.5 parts by weight to 4.5 parts by weight, more specifically 1 part by weight to 4 parts by weight. In this case, the crosslinking active agent may further improve the degree of crosslinking of the thermoplastic elastomer for the air intake hose, thereby realizing a more balanced mechanical property.

Another embodiment of the present invention relates to an air intake hose for automobiles that is formed by dynamically crosslinking the thermoplastic elastomer composition for air intake hoses described above.

The thermoplastic elastomer composition for an air intake hose of the present invention has superior light weight compared to a conventional rubber material, can realize high oil resistance and rigidity, has excellent flowability and moldability, does not generate chlorine gas, and is of a vulcanization process. It can be omitted, and the molded product can be recycled.

In the compounding process of the thermoplastic elastomer composition for the air intake hose described above, the ethylene-propylene-diene monomer rubber may be partially or completely crosslinked to greatly improve physical properties. Accordingly, the dynamic crosslinked product of the thermoplastic elastomer composition for an air intake hose of the present invention has a physical property difference from a simple blend.

The crosslinking degree of the thermoplastic elastomer composition for the dynamic crosslinked air intake hose may be, for example, 90% to 99%. Within the above range, mechanical properties, flowability and formability may be excellent.

Specifically, the above-mentioned thermoplastic elastomer composition for an air intake hose is primarily blended in a kneader mixer to prepare an oil rubber masterbatch (ORMB). After the primary blended master batch (ORMB) is put into a L/D=60 twin-screw extruder (for example, co-rotating intermesh type), at 250 rpm to 450 rpm and 160°C to 210°C temperature conditions It can be extruded to dynamically crosslink. The final pellet can be obtained by pelletizing (eg underwaterpelletizing) the dynamically crosslinked composition.

In addition, the thermoplastic elastomer composition for air intake hoses may be dynamically crosslinked and then injection molded at a temperature of 180°C to 220°C to produce air intake hoses.

1 is a view showing an air intake hose for a vehicle according to an example of the present invention. Referring to FIG. 1, the air intake hose 10 for a vehicle passes air introduced through the suction unit 11 connected to the outside of the vehicle through a filtration device such as an air cleaner, and then the vehicle through the outlet unit 12. It serves as a passage to the engine. In addition, it is additionally mounted in a vehicle engine room to perform a function of absorbing vibrations by an automobile engine.

According to these characteristics, the air intake hose 10 is manufactured in the form of a pipe, and may be manufactured in a complex form to facilitate the arrangement in the engine room. In addition, it may be connected through an air cleaner and the like bellows structure 13.

The air intake hose 10 for automobiles formed from the elastic composition for the air intake hose of the present invention is advantageously provided in an engine room by implementing high oil resistance and mechanical properties, and has excellent flowability and formability, so that the bellows structure 13 ) Has advantageous properties for realizing complex formation.

The air intake hose may satisfy the following physical property values before and after the oil resistance test for a specimen tested for oil resistance at a temperature of 125±2°C and 70 hours in ASTM NO.3 OIL according to ISO 1817 standard:

In an embodiment, the air intake hose may have a hardness change (shore A) value of -22 shore A to 0 shore A, specifically -20 to 0, and more specifically -17 to 0. In this case, the change in hardness is small, and the productability of the air intake hose can be further improved.

In an embodiment, the air intake hose has a tensile strength change rate (%) of -33% to 0%, specifically -32% to 0%, and more specifically -29% to 0%. In this case, the change in tensile strength is small, and the productability of the air intake hose can be further improved.

In an embodiment, the air intake hose may have an elongation change rate (%) of -68% to 0%, specifically -60% to 0%, and more specifically -57% to 0%. In this case, the change in elongation is small, and the productability of the air intake hose can be further improved.

In an embodiment, the air intake hose may have a 100%M change rate (%) of -15% to 0%, specifically -7% to 0%, and more specifically -2% to 0%. In this case, there is little change in the value of 100% M, and the productability of the air intake hose can be further improved.

In an embodiment, the air intake hose may have a volume change rate (%) of 0% to 93%, specifically 0% to 71%, and more specifically 0% to 68%. In this case, the product value of the air intake hose may be further improved due to a small change in volume value.

Within the range of the above properties, when applied to the air intake hose formed from the thermoplastic elastomer composition for an air intake hose of the present invention, while implementing high oil resistance and mechanical properties, excellent flowability and formability, which is advantageous for application to the formation of a bellows structure It has characteristics.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is provided as a preferred example of the present invention and cannot be interpreted as limiting the present invention by any means.

Example

(A) Ethylene-propylene-diene rubber

(A1): EPDM rubber A, manufacturer: LANXESS, product name: Keltan 4869C, impregnated oil: paraffin oil 100phr (Parts per hundred resin), unit content derived from ENB (ethylidene-2-norbornene): 8.7% by weight, propylene monomer Derived unit content: 29.3% by weight, ethylene monomer derived unit content: 62% by weight, 125°C ML 1+4 Mooney viscosity: 48 MU

(A2): EPDM rubber B, manufacturer: VERSALIS, product name: Dutral TER WO65, impregnated oil: paraffin oil 50phr (Parts per hundred resin), ENB (ethylidene-2-norbornene) content: 8% by weight, derived from propylene monomer Unit content: 32% by weight, unit content derived from ethylene monomer: 60% by weight, 125°C ML 1+4 Mooney viscosity: 43MU

(A3): EPDM rubber C, manufacturer: Kumho Polychem, product name: KEP-9590, impregnated oil: 0phr (Parts per hundred resin), ENB (ethylidene-2-norbornene) content: 10% by weight, Unit content derived from propylene monomer: 38 wt%, Unit content derived from ethylene monomer: 52 wt%, 125°C ML 1+4 Mooney viscosity: 95 MU

(A4): EPDM rubber D, manufacturer: Kumho Polychem, product name: KEP-960NF, impregnated oil: paraffin oil 50phr (Parts per hundred resin), ENB (ethylidene-2-norbornene) content: 5.7% by weight, propylene Unit content derived from monomer: 24.3 wt%, Unit content derived from ethylene monomer: 70 wt%, 125°C ML 1+4 Mooney viscosity: 49 MU

(A5): EPDM rubber B, manufacturer: VERSALIS, product name: Dutral TER 4437 WO, impregnated oil: paraffin oil 40 phr (Parts per hundred resin), ENB (ethylidene-2-norbornene) content: 4.5% by weight, propylene Unit content derived from monomer: 32% by weight, Unit content derived from ethylene monomer: 63.5% by weight, 125°C ML 1+4 Mooney viscosity: 57 MU

(B) Polypropylene resin

: Homo-PP, Manufacturer: Lotte Chemical, Product name: Y-120 grade, MI: 1.0 g/10min

(C) Crosslinking agent

(C1): Phenolic crosslinking agent, Manufacturer: SI group, Product name: SP-1045, Methylol content: 9.5~1.1%

(C2): sulfur-based crosslinking agent, manufacturer: Aldrich, product name: Sulfur (Cas No.:7704-34-9)

(C3): Peroxide-based crosslinking agent, manufacturer: TCI, product name: Dicumyl peroxide (Cas No. 80-43-3)

(D) Paraffin oil

: Paraffin oil, Manufacturer: Shell, Product name: Catenex T-145 grade, 40℃ Kinematic viscosity: 108.1 cSt

(E) Inorganic filler

: Talc, manufacturer: Koch, product name: KCM-6300, number average particle size: 5.5±1.0 ㎛

(F) Crosslinking activator

(F1): Zinc oxide, Manufacturer: Hanil Chemical, Product name: Zinc oxide

Example 1

Each component was added to the reactor according to the composition shown in Table 1 below, and then mixed by mixing through a kneader to uniformly mix to prepare an elastic composition for an air intake hose.

Specifically, the above-described thermoplastic elastomer composition for an air intake hose is primarily blended in a kneader mixer to prepare an oil rubber masterbatch (ORMB). After the primary blended master batch (ORMB) was put into a L/D=60 twin-screw extruder (co-rotating intermesh type), it was extruded at a temperature of 350 rpm and 160°C to 210°C to dynamically crosslink and dynamic crosslink The resulting composition was pelleted underwater to obtain a final pellet.

The pellets thus obtained were injection molded at a temperature condition of 180°C to 220°C to prepare an air intake hose.

Example 2

An air intake hose was prepared in the same manner as in Example 1, except that the composition was changed as described in Table 1 below.

Example 3

An air intake hose was prepared in the same manner as in Example 1, except that the composition was changed as described in Table 1 below.

Comparative Examples 1 to 4

An air intake hose was prepared in the same manner as in Example 1, except that the composition was changed as described in Table 1 below.

Formulation Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 (A) (A1) EPDM rubber A 100 - - - - - - (A2) EPDM rubber B - 100 - - - 100 100 (A3) EPDM rubber C - - 100 - - - - (A4) EPDM rubber D - - - 100 - - - (A5) EPDM rubber E - - - - 100 - - (B) Polypropylene resin 45 45 45 45 45 45 45 (C) (C1)
Crosslinking agent phenolic resin 4 4 4 4 4 - - (C2)
Crosslinking agent sulfur - - - - - 4 - (C3)
Crosslinking agent peroxide - - - - - - 4 (D) Paraffin oil
(Including impregnated oil) 160 160 160 160 160 160 160 (E) Inorganic filler, Talc 50 50 50 50 50 50 50 (F) Crosslinking Activator, ZnO 2 2 2 2 2 2 2

<Physical property evaluation>

In order to measure the properties of the compositions prepared in Examples and Comparative Examples, the properties of the following items were evaluated, and the results are shown in Table 2.

The composition was evaluated for physical properties according to the conditions specified below.

(1) Basic properties

-Shore A hardness: measured according to ISO 868 standard.

-Tensile properties (tensile strength, kg/cm ² ): Measured according to ISO 37 (Dumbbell type 1) standard.

-Elongation (%): Measured at room temperature according to ISO 37 (Dumbbell type 1) standard.

-100%M (100%Modulus, kg/cm ² ): Modulus value when the gap between the specimens and the specimen reaches the original double. It was measured at room temperature according to the ISO 37 (Dumbbell type 1) standard.

-Tear properties (tear strength, kg/cm): Measured according to ISO 34-1 standard.

(2) Compressed permanent shrinkage (%): According to ISO 815 standard, circular specimens with a diameter of 29±0.5mm and a thickness of 12.5±0.5mm were compressed at a temperature of 125±2℃ for 70 hours at a compression rate of 15%, before and after the test. After measuring the thickness, the compression reduction rate was calculated according to the following Equation 1.

<Equation 1>

Compressed permanent shrinkage (%) = {(B-A) / (B-C)} x 100

In Equation 1, A is a thickness measured after subjecting a specimen having a diameter of 29±0.5mm and a thickness of 12.5±0.5mm to high temperature compression treatment at a temperature of 125±2℃ for 15 hours at 15% compression rate, and B is the specimen. It is the thickness measured before the high temperature compression treatment, and C is the thickness of the compression spacer. However, the spacer for 15% compression was 10.63±0.1mm thick.

(3) Heat aging resistance: After measuring the basic physical properties described above, the specimens were subjected to heat aging for 168 hours at a temperature of 125±2°C according to ISO 188 standards, and then each basic physical property was measured again to change the hardness of each. Degree (shore A), tensile strength change rate (%), elongation change rate (%) and 100%M change rate (%) was calculated.

(4) Oil resistance: After measuring the basic properties described above, the oil resistance test was conducted for 70 hours at 125±2° C. in ASTM NO.3 OIL according to ISO 1817 standards, and then measured for each basic property again, each hardness The degree of change (shore A), the rate of change in tensile strength (%), the rate of change in elongation (%), the rate of change in 100% M (%) and the rate of change in volume (%) were calculated according to Equations 2 to 7 below:

The hardness gradient (shore A) was calculated according to Equation 2 below.

<Equation 2>

Hardness gradient (shore A) = (B ₂ -A ₂ )

In Equation 2, B ₂ is the shore A hardness measured after the oil resistance test, and A ₂ is the shore A hardness measured before the oil resistance test.

The rate of change in tensile strength (%) was calculated according to Equation 3 below.

<Equation 3>

Tensile strength change rate (%) = {(B ₃ -A ₃ ) / A ₃ } X 100

In Equation 3, B ₃ is the tensile strength (kg/cm ² ) measured after the oil resistance test, and A ₃ is the tensile strength (kg/cm ² ) measured before the oil resistance test.

The elongation change rate (%) was calculated according to Equation 4 below.

<Equation 4>

Elongation rate of change (%) = {(B ₄ -A ₄ ) / A ₄ } X 100

In Equation 4, B ₄ is the elongation (%) measured after the oil resistance test, and A ₄ is the elongation (%) measured before the oil resistance test.

The 100% M change rate (%) was calculated according to Equation 5 below.

<Equation 5>

Elongation rate of change (%) = {(B ₅ -A ₅ ) / A ₅ } X 100

In Equation 5, B ₅ is a 100% M value (kg/cm ² ) measured after the oil resistance test, and A ₅ is a 100% M value (kg/cm ² ) measured before the oil resistance test.

The volume change rate (%) was calculated according to Equation 6 below.

<Equation 6>

Volume change rate (%) = {(B ₆ -A ₆ ) / A ₆ } X 100

In Equation 6, B ₆ is a volume value (mL) measured after the oil resistance test, and A ₆ is a volume value (mL) measured before the oil resistance test, where the volume (volume, mL) is density according to ISO 1183 standard. After measuring (g/mL), it was calculated through Equation 7 below.

<Equation 7>

Volume (mL) = {mass (g) / density (g/mL)}

Property evaluation items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 basic
Properties Hardness, Shore A 73 73 74 72 72 70 71 Tensile strength, kg/cm ² 71 72 73 68 69 79 70 Elongation% 430 430 450 390 380 280 380 100%M, kg/cm ² 36 36 36 34 33 41 35 Tear strength, kg/cm 32 33 33 28 30 37 35 Compressed permanent shrinkage% 35 36 38 40 40 52 49 Heat aging resistance Hardness gradient,
Shore A 2 2 3 5 8 11 10 The tensile strength
Rate of change,% -5 -5 -5 -7 -9 -20 -14 Elongation rate of change,% -17 -18 -17 -21 -26 -42 -38 100%M change rate,% 16 19 20 24 24 36 30 Oil resistance Hardness change,
Shore A -17 -20 -22 -26 -29 -39 -37 The tensile strength
Rate of change,% -29 -32 -33 -33 -35 -71 -55 Elongation rate of change,% -57 -60 -68 -68 -70 -79 -67 100%M change rate,% -2 -7 -15 -20 -26 -42 -41 Volume change rate,% 68 71 93 97 100 144 138

As can be seen through Table 2, the elastic composition according to the embodiment of the present invention is very excellent in heat resistance, reduced compression rate, especially oil resistance than conventional products.

The elastic composition of the present invention not only satisfies all of the basic physical properties of the required tensile properties of 55 kg/cm ² , elongation of 340% or higher, and 100% M 20 kg/cm ² or higher, which are required in the automotive air intake hose material It was found to improve to the level.

In addition, it can be seen that the elastic composition of the present invention has an excellent effect of reducing the compression permanent shrinkage rate.

Referring to Table 2, the elastic composition of the present invention has a small degree of hardness change even in a heat aging test, and reduces the degree of tensile strength change rate, elongation change rate, and 100%M change rate to a small extent, thereby improving the effect. Can be seen.

Referring to Table 2, the elastic composition of the present invention has a small degree of hardness change even in the oil resistance test, and reduces the degree of tensile strength change rate, elongation change rate, 100%M change rate and volume change rate to a small extent, thereby improving the effect. It can be seen that there is.

In addition, the elastic composition of Examples 1 to 3 of the present invention exhibited a smaller value of the volume change rate in the oil resistance test compared to Comparative Examples 1 to 4. Through this, it can be confirmed that the resistance to oil is high.

In Comparative Examples 1 and 2, EPDM having a lower ENB content than the range suggested by the present invention was used. As a result, it was found that compared to Examples 1 to 3, the basic physical properties, compression permanent shrinkage, and heat resistance were slightly lowered, and oil resistance was significantly lowered.

In the case of Comparative Examples 2 to 4, a sulfur crosslinking agent and a peroxide crosslinking agent other than the phenol crosslinking agent proposed in the present invention were used. As a result, compared to Examples 1 to 2 of the present invention, the tensile strength, 100% M, and tear strength were equal to or slightly better than each other, but the compression permanent shrinkage rate and heat resistance were lowered, and particularly, a drop in oil resistance was evident. Did.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (9)

(A) 100 parts by weight of ethylene-propylene-diene rubber,
(B) 30 parts by weight to 80 parts by weight of polypropylene resin; And
(C) 2 parts by weight to 8 parts by weight of a phenolic crosslinking agent; Including,
The (A) ethylene-propylene-diene rubber is a thermoplastic component for air intake hoses having a propylene monomer derived unit content of 20% to 50% by weight and an ethylidene-2-norbornene derived unit content of 8% to 10% by weight. Elastomer composition.
According to claim 1,
The thermoplastic elastomer composition for the air intake hose
Based on (A) 100 parts by weight of ethylene-propylene-diene rubber,
(D) 100 parts by weight to 200 parts by weight of paraffin oil;
(E) 30 parts by weight to 80 parts by weight of an inorganic filler; And
(F) 0.1 to 5 parts by weight of a crosslinking active agent; Thermoplastic elastomer composition for an air intake hose further comprising at least one of.
According to claim 1,
The (A) ethylene-propylene-diene rubber is a thermoplastic elastomer composition for an air intake hose having a ML1+4 Mooney viscosity of 20 MU to 100 MU at 125°C.
According to claim 1,
The (A) ethylene-propylene-diene rubber is a thermoplastic elastomer composition for an air intake hose comprising an impregnated oil in an amount of 50 phr to 100 phr.
According to claim 1,
The polypropylene resin (B) has a heat deflection temperature (HDT) of 100°C to 150°C, a Vickers softening point (VST) of 135°C to 175°C, a melt index of 0.5 g/10min to 1.5 g/10min, and a density. Is a thermoplastic elastomer composition for air intake hoses of 0.6 g / cm ³ to 1.2 g / cm ³ .
According to claim 2,
The (E) inorganic filler is a talc, clay, calcium carbonate, wollastonite, calcium sulfate, magnesium oxide, calcium stearate, mica, calcium silicate, and carbon black, thermoplastic elastomer for intake hose Composition.
According to claim 2,
The (F) crosslinking active agent is a thermoplastic elastomer composition for an air intake hose comprising at least one of zinc oxide, tin chloride and zinc stearate.
An air intake hose formed by dynamically crosslinking the thermoplastic elastomer composition for an air intake hose according to any one of claims 1 to 7.
The method of claim 8,
The air intake hose according to ISO 1817 standards before and after the oil resistance test for the oil resistance test for 125 ± 2 ℃ temperature and 70 hours in ASTM NO.3 OIL
The hardness gradient value is -22 shore A to 0 shore A,
Tensile strength change rate (%) is -33% to 0%,
Elongation change rate (%) is -68% to 0%,
100%M change rate (%) is -15% to 0%,
Air intake hose with a volume change rate (%) of 0% to 93%.

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