JPH11349734A - Thermoplastic elastomer composition and hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic elastomer composition having excellent oil resistance, thermal aging resistance and low temperature physical properties by compounding a thermoplastic polyamide-based resin for a continuous phase and two kinds of specific rubbers for a dispersion phase and subsequently dynamically cross-linking the composition. SOLUTION: This thermoplastic elastomer composition is obtained by compounding (A) a thermoplastic polyamide-based resin for a continuous phase and (B) acrylonitrile-butadiene copolymer rubber and (C) an ethylene-acrylate ester copolymer rubber for a dispersion phase and subsequently dynamically cross-linking the composition. The component A is preferably nylon 6, nylon 66, nylon 666, etc. The component B is a copolymer of (i) acrylonitrile with (ii) butadiene, wherein the content of the component (i) is preferably 10-50 wt.%. The component C is a (multi-component) copolymer of (iii) ethylene with (iv) a (meth)acrylate ester and, if necessary, (v) a cross-linking monomer. The components A, B and C are preferably compounded in an A/(B+C) weight ratio of 70/30 to 20/80.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic elastomer composition having excellent oil resistance, heat aging resistance and low temperature properties, and a hose excellent in oil resistance, heat aging resistance and low temperature properties.

[0002]

2. Description of the Related Art Various compositions using a rubber and a polyamide resin in consideration of applications such as a fuel hose contacting gasoline have been disclosed. For example, a thermoplastic elastomer containing a nitrile rubber and a polyamide resin, and a thermoplastic elastomer containing a nitrile rubber, an acrylic rubber, and a polyamide resin are disclosed. However, although the former is excellent in oil resistance, it has a problem that heat resistance and low-temperature physical properties are inferior since rubber has a double bond in its molecular structure. The latter is excellent in oil resistance and heat resistance, but has a problem of inferior low-temperature properties.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic elastomer composition having excellent oil resistance, heat aging resistance and low temperature properties, and a hose having excellent oil resistance, heat aging resistance and low temperature properties. is there.

[0004]

That is, according to the present invention, the continuous phase is a thermoplastic polyamide resin (A), and the dispersed phase is an acrylonitrile-butadiene rubber (B) and an ethylene-acrylate copolymer rubber ( C)
Provided is a dynamically crosslinked thermoplastic elastomer composition.

The composition ratio (weight ratio) of the components (A) and (B) + (C) (A) / (B) + (C) is 70 / 30-
It is preferably 20/80.

The composition ratio (weight ratio) (B) / (C) of the components (B) and (C) is 10/90 to 90/10
It is preferred that Further, the ethylene-acrylate copolymer rubber as the component (C) is preferably a multi-component copolymer with a crosslinkable monomer having an epoxy group or a carboxyl group.

Further, the present invention provides a hose in which the above-mentioned thermoplastic elastomer composition is contained at least in an inner tube.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. A first aspect of the present invention is a thermoplastic elastomer composition in which a thermoplastic polyamide-based resin is a continuous phase, and a dispersed phase is an acrylonitrile-butadiene rubber and an ethylene-acrylate copolymer rubber. A second aspect of the present invention is a hose including the above thermoplastic elastomer composition in at least an inner tube.

The thermoplastic polyamide resin (A) used as the continuous phase in the thermoplastic elastomer composition (hereinafter referred to as the composition of the present invention) according to the first aspect of the present invention includes nylon 46 and nylon 46. 6, nylon 66, nylon 610, nylon 611, nylon 61
2, nylon 11, nylon 12, nylon 666, M
Single or copolycondensates such as XD6 nylon and nylon 6T can be mentioned, and one or a mixture of two or more thereof can be used. Among these, nylon 6, nylon 66, and nylon 666 are preferable.

The acrylonitrile-butadiene rubber (B) contained in the composition of the present invention is a copolymer of (b-1) acrylonitrile and (b-2) butadiene. Acrylonitrile-butadiene rubber (B) used in the present invention
In (b-1) acrylonitrile content is 10
５０50% by weight, preferably 15-40% by weight.
(B-1) If the acrylonitrile content is less than 10% by weight, oil resistance is not sufficient, and if it is more than 50% by weight, cold resistance (low-temperature physical properties) becomes poor. In the present invention, as the acrylonitrile-butadiene rubber (B),
Those to which a plasticizer has been added and those to which a filler has been added can also be used. Component (B) contains these rubbers,
Acrylonitrile-butadiene rubbers having different acrylonitrile contents may be used alone or in combination of two or more.

The ethylene-acrylate copolymer rubber (C) contained in the composition of the present invention is a copolymer of (c-1) ethylene and (c-2) acrylate, and further comprises (c) -3) It is preferably a multi-component copolymer with a crosslinkable monomer. (C-2) Acrylates include methacrylates, which are esters of alcohols having 1 to 8 carbon atoms. Specifically, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, t-butyl acrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, methacrylic acid 2 -Ethylhexyl and the like, and these may be used alone or in combination of two or more. The crosslinking monomer (c-3) preferably contains an epoxy group or a carboxyl group.

In the ethylene-acrylate copolymer rubber (C) used in the present invention, the ratio of (c-1) ethylene to (c-2) acrylate or methacrylate is from 50 to 50 in molar ratio.
85: 50-15, preferably 58-80: 42-20
It is. (C-2) When the content of the acrylate or methacrylate exceeds 50 mol%, the embrittlement point becomes high, so that it is difficult to use the elastomer at a low temperature.
On the other hand, if the amount is less than 15 mol%, sufficient elasticity of the copolymer as an elastomer cannot be obtained. The content of the (c-3) crosslinking monomer in the ethylene-acrylate copolymer rubber (C) is 0.05 to 5 with respect to the sum of the number of moles of (c-1) and (c-2). Mol% is preferred, and 0.1 to 3
Molar% is more preferred. When (c-3) also contains an epoxy group or a carboxyl group, it reacts with the amide group of the resin component (A) forming a continuous phase, and has the effect of strengthening the interface with the resin component (A). You. The above component (C) may be used alone or in combination of two or more.

In the present invention, the rubber component comprises acrylonitrile-butadiene rubber (B) and ethylene-acrylate copolymer rubber (C), and these rubber components are dispersed in the thermoplastic elastomer composition of the present invention. Becomes Components (B) and (C) may be dispersed as domains (dispersed phase) independently, components (C) become domains with component (B) covering components, component (B) is represented by ( C) becomes a domain in a state of being covered. Among these, it is preferable that the acrylonitrile-butadiene rubber (B) is formed into a domain in a state where the ethylene-acrylate copolymer rubber (C) covers the acrylonitrile-butadiene rubber (B) from the viewpoint of heat resistance, oil resistance, and low-temperature physical properties.

The amount (weight ratio) of components (A), (B) and (C) is (A) + (B) + (C) = 100 parts by weight, and (A) / [(B) + (C)] = 70 / 30-
20/80, preferably (A) / [(B) +
(C)] = 50/50 to 25/75. By blending in this range, a thermoplastic elastomer composition having well-balanced physical properties can be obtained.

The weight ratio of (B) and (C) in the rubber component is (B) / (C) = 10 / 90-90 / 10, preferably (B) / (C) = 30 / 70-90 / It is 10. This is to balance the heat aging resistance, low temperature properties, and oil resistance of the obtained thermoplastic elastomer composition.

Further, in order to disperse the acrylonitrile-butadiene rubber (B) as a domain in the composition of the present invention in a state covered by the ethylene-acrylate copolymer rubber (C), a matrix resin (component (A)) and the volume fraction (φ) of the acrylonitrile-butadiene rubber (B) and the ethylene-acrylate copolymer rubber (C) in the rubber dispersed phase (components (B) and (C)) and the rubber phase. The melt viscosity (η) is set to satisfy the following relationship. _{α 1 = (φ B + C} / φ A) / (η A / η B + C) <1 cutlet _{α 2 = (φ B / φ} C) / (η C / η B) <1 where volume fraction and is the case where the total volume to 1, which shows the percentage of the total volume of a certain phase in the volume fraction, is _{φ a + φ B + φ C} = φ B + C + φ a = 1. The melt viscosity is a melt viscosity measured by a capillary rheometer. The melt viscosity (η _{B + C} ) of the rubber phase is a value obtained when the components (B) and (C) are homogeneously mixed to form a composition. Shows the melt viscosity. The volume and the melt viscosity are defined by the temperature at the time of kneading and the shear rate.

The vulcanizing agent (crosslinking agent) used in the present invention is not particularly limited, and is usually used for vulcanizing (crosslinking) acrylonitrile-butadiene rubber or ethylene-acrylate copolymer rubber. (Crosslinking agent) can be used. The same applies to the amount used. As such a vulcanizing agent (crosslinking agent), for example, a sulfur-based vulcanizing agent,
Organic peroxide-based vulcanizing agents, phenolic resin-based crosslinking agents, organic ammonium salt-based crosslinking agents, polyamine-based crosslinking agents, polycarboxylic acid crosslinking agents, and the like can be given. The above may be used in combination. Specifically, examples of the sulfur-based vulcanizing agent include powdered sulfur, precipitated sulfur, highly dispersible sulfur, surface-treated sulfur, insoluble sulfur, dimorpholine disulfide, and alkylphenol disulfide. ~ 20
phr [parts by weight per 100 parts by weight of rubber component (polymer)] can be used. Examples of the organic peroxide vulcanizing agent include benzoyl peroxide, t-butyl hydroperoxide, 2,4-bichlorobenzoyl peroxide, and 2,5-dimethyl-2,5-di (t
-Butylperoxy) hexane, 2,5-dimethylhexane-2,5-di (peroxylbenzoate) and the like, and for example, about 1 to 20 phr can be used. Further, examples of the phenolic resin-based cross-linking agent include brominated alkylphenol resins, and mixed cross-linking systems containing a halogen donor such as tin chloride and chloroprene and an alkylphenol resin.
About r can be used. In addition, zinc flower (5
phr), magnesium oxide (about 4 phr), litharge (about 10 to 20 phr), p-quinonedioxime, p-dibenzoylquinonedioxime, tetrachloro-p-benzoquinone, poly-p-dinitrosobenzene (2- 10 phr), methylene dianiline (0.2
To about 10 phr).

Further, the composition of the present invention may optionally contain other compounding agents such as a crosslinking accelerator, a reinforcing material, an antioxidant, and a processing aid.

The composition of the present invention is a thermoplastic elastomer composition produced by dynamic crosslinking, in which the crosslinking of rubber proceeds while kneading the thermoplastic resin and the rubber composition. It is. By using such a manufacturing method, the obtained thermoplastic elastomer composition has a crosslinked rubber phase in which at least a part thereof becomes a discontinuous phase in a thermoplastic resin phase in which at least a part thereof becomes a continuous phase, is finely dispersed. Since the resulting thermoplastic elastomer composition exhibits the same behavior as the crosslinked rubber, and since at least the continuous phase is a thermoplastic resin phase, at the time of molding processing, processing according to the thermoplastic resin Is possible.

In the production of the composition of the present invention, the machine used for kneading the components (A), (B) and (C) is not particularly limited, but may be a screw extruder, a kneader, a Banbury mixer, a twin screw kneader. An extruder and the like are exemplified. Above all, considering the kneading of the components (A) (resin component), the components (B) and (C) (rubber composition), and the dynamic crosslinking of the components (B) and (C), the twin-screw kneading extruder is used. It is preferred to use. Further, two or more types of kneaders may be used to knead sequentially.

The composition of the present invention obtained by the above-mentioned method comprises:
It is preferable that the rubber components (B) and (C) are sufficiently crosslinked by the vulcanizing agent (crosslinking agent). Here, “fully crosslinked” means that the gelation ratio is preferably 80%.
-100%, more preferably 90-100%. If the gelation ratio is less than 80%, the resulting composition has insufficient oil resistance and compression set, which is not preferable. Here, the gelation rate is confirmed by finely pulverizing the obtained composition by freeze pulverization or the like and then performing Soxhlet extraction over multiple stages. That is, if the extraction rate is less than 20%, the gelation rate is 80% or more.

Hereinafter, an example of the production method will be described more specifically, taking as an example kneading by a conventional twin-screw kneading extruder. The components (B) and (C) are kneaded using a rubber kneading machine such as a Banbury mixer and, if necessary, with the addition of a reinforcing agent, an antioxidant, a processing aid, etc., and containing no crosslinking system.
After forming a so-called master batch, it is prepared by pelletizing with a rubber pelletizer. When a vulcanizing agent having a slow crosslinking rate is used, a master batch containing the vulcanizing agent may be used. Further, the components (B) and (C) may be pelletized separately, but in order to cover the component (B) with the component (C), the components (B) and (C) are kneaded together in advance and the pellets are mixed. It is preferable to make it. The components (B) and (C) thus pelletized in advance and the component (A) in the form of pellets are charged from the input port of the twin-screw kneading extruder,
Disperse components (B) and (C) in component (A).

After that, when the components (A), (B) and (C) are sufficiently kneaded, a crosslinking agent or a crosslinking aid is added from the input port of the twin-screw kneading extruder. Crosslink (dynamically crosslink) components (B) and (C). When a vulcanizing agent is previously included in the rubber pellets, it is not necessary to add a new vulcanizing agent. By performing the crosslinking in this manner, the components (B) and (C) are sufficiently dispersed in the component (A), and the components (B) and (C) are sufficiently finely divided. To prepare a thermoplastic elastomer composition in which the components (B) and (C) are stably dispersed as the dispersed phase (domain) in the component (A) forming the continuous phase (matrix). In such a thermoplastic elastomer composition, the particle diameter of the crosslinked rubber composition (the component (B) or (C) alone or the particles containing the components (B) and (C)) as the dispersed phase is 50 μm or less. It is more preferable that the thickness be 10 to 1 μm.

The composition of the present invention may further comprise a reinforcing material, a softener,
When a compounding agent such as an antioxidant is added, the compounding agent for the rubber components (B) and (C) may be added during the kneading, but the compounding agent other than the crosslinking agent is added before the kneading. It is better to mix them in advance. The compounding agent for the resin component (A) may be previously mixed before the kneading, or may be added during the kneading.

The kneading temperature of the components (A), (B) and (C) is, for example, 150.
The temperature is preferably from 300 to 300 ° C., particularly preferably from 180 to 250 ° C., and the shear rate during kneading is preferably from 100 to 5000 sec ⁻¹ , particularly preferably from 500 to 2500 sec ⁻¹ . The time for the entire melt kneading is preferably 30 seconds to 10 minutes, and the crosslinking time after the addition of the crosslinking agent is preferably 15 seconds to 5 minutes.

The thermoplastic elastomer composition of the present invention thus obtained has flexibility, oil resistance, heat aging resistance,
Excellent low temperature properties. The use of the thermoplastic elastomer composition of the present invention is not particularly limited, but is preferably used when oil resistance and heat resistance are required. For example, it is suitably used for oil-resistant hoses, automobiles that require oil resistance and heat resistance, parts around the engine of construction machinery, and the like.

Next, a hose according to a second embodiment of the present invention will be described with reference to an embodiment shown in the accompanying drawings. FIG. 1 is a perspective view of the hose of the present invention with each layer cut away. The hose 1 has an inner tube 2, a reinforcing layer 3, and an outer tube 4, and has adhesive layers 5, 6 between the reinforcing layer and the inner tube and between the reinforcing layer and the outer tube, respectively. The hose 1 of the present invention is characterized in that at least the inner tube 2 contains the composition of the present invention.

In the hose of the present invention, when the outer tube or the inner tube is composed of a plurality of layers, and when the composition of the present invention is used for any one of the layers, the substance that can be used for the other layers includes: , NBR, IIR, EPDM and other vulcanized rubbers, thermoplastic elastomer compositions such as polyamide elastomers, polyester elastomers, polyolefin elastomers, and EPDM / PP thermoplastic elastomer compositions. Among the thermoplastic elastomer compositions, an EPDM / PP-based thermoplastic elastomer composition having excellent flexibility is preferable. Specifically, Santoprene 101-73 manufactured by AES is preferably used.

In the hose of the present invention, the reinforcing layer comprises:
There is no particular limitation. Any of a blade-shaped member and a spiral-shaped member may be used. The material used may be a thread or a wire. As the reinforcing yarn, vinylon fiber, rayon fiber, polyester fiber,
Examples include yarns made of nylon fibers, aromatic polyamide fibers, and the like. Examples of the reinforcing wire include a hard steel wire, and more specifically, a brass-plated wire or a galvanized wire for rust prevention and adhesion.

In the hose of the present invention, maleic acid-modified polyolefin, particularly maleic acid-modified propylene, can be used for the adhesive layer between the layers.

The hose of the present invention is a hose having at least an inner tube, a reinforcing layer, and an outer tube, and it is preferable that each layer is joined by an adhesive layer. In one embodiment of the hose of the present invention shown in FIG. 1, the inner pipe 2 and the outer pipe 4 are each one layer, but the hose of the present invention is such that the inner pipe and the outer pipe are each formed as a multi-layer. The reinforcing layer may be a single layer or a multilayer.

Next, a method for manufacturing a hose according to the present invention will be described with reference to an embodiment shown in the accompanying drawings. FIG.
FIG. 2 is a diagram schematically illustrating a manufacturing process of an example of the hose of the present invention. The hose of the present invention can be manufactured, for example, as follows. That is, as shown in FIG. 2, an extruder 8 for an inner tube material is placed on a mandrel 7 on which a release agent is applied in advance.
A thermoplastic elastomer composition for an inner pipe is extruded from the extruder 9 for an adhesive simultaneously, and two layers are simultaneously extruded from the extruder to form a tube in an inner tube forming die 10. 11 is formed. At this time, after extruding the inner tube in advance, the adhesive layer may be extruded on the inner tube. next,
A reinforcing layer 13 is formed on the inner tube 11 and the adhesive layer using a reinforcing layer forming machine 12, and the reinforcing layer 13 is knitted into a spiral shape or a blade shape by aligning a plurality of reinforcing yarns or reinforcing wires. It is assembled and formed. After forming the reinforcing layer 13, local heating is performed on the reinforcing layer 13 by the heating device 14. At this time, when the reinforcing layer 13 is heated to 100 to 350 ° C., if the adhesive layer is a maleic acid-modified polyolefin-based resin or the like, the adhesive layer is melted, and it is possible to perform sufficient bonding. When the adhesive layer and the wire are sufficiently bonded, the durability of the hose is improved. Finally, the fully heated reinforcement layer 1
3, an adhesive layer is extruded from the extruder 16 for the adhesive in the same manner as the inner tube, and a thermoplastic elastomer composition for the outer tube is extruded simultaneously from the extruder 17 for the outer tube onto the outer tube. The outer tube 18 is formed by forming into a hose shape in the forming die 15. At the time of forming the outer tube, first, the adhesive layer is extruded, and then the thermoplastic elastomer composition for the outer tube is extruded.
May be formed. Also, in FIG.
Is performed before the outer tube 18 is formed,
Even after the outer tube 18 is covered, the outer tube 18 and the adhesive layer are similarly strongly bonded. By removing the mandrel 7 after forming the hose in this way, a desired hose is obtained.

The hose of the present invention thus obtained is excellent in oil resistance, heat aging resistance, and low-temperature properties because the composition of the present invention is used in at least the inner tube.

[0034]

The present invention will be specifically described below with reference to examples.

(Examples 1 to 9 and Comparative Examples 1 to 5) Production of thermoplastic elastomer compositions The following table was prepared using various compounding agents such as a resin component, a rubber component, and a crosslinking agent. Various elastomer compositions shown in No. 1 were produced. The rubber component and the compounding material other than the resin were first mixed at an initial temperature of 40 ° C. for 5 minutes using a closed Banbury mixer to prepare a rubber master batch. Next, the rubber masterbatch is pelletized with a rubber pelletizer, and the obtained rubber pellets,
The resin pellets were put into a twin-screw kneader to perform melt-kneading. The kneading conditions were a kneading temperature of 220 ° C. for 5 minutes and a shear rate of 500 sec ⁻¹ . Crosslinking was performed in a kneader, and a rubber component dispersed as a dispersed phase was dynamically crosslinked in a resin component as a continuous phase. The composition obtained as described above was continuously extruded into a strand from an extruder, cooled with water, and then cut with a cutter to obtain a pellet-shaped thermoplastic elastomer composition. In Comparative Example 5, the composition obtained in Comparative Example 3 and the composition obtained in Comparative Example 4 were mixed in a ratio of 50: 5.
These were mixed at a ratio of 0.

Evaluation of physical properties
In compliance with IS K6301, 1) physical properties in normal state (25 ° C.): Hardness, tensile strength (T _B), elongation (E _B), 2) low temperature properties by low-temperature embrittlement test (-40 ℃), 3) high temperature Physical properties (120 ° C.): Tensile strength (T _B ), elongation (E _B ), 4) Tensile strength (T _B ) retention as a retention rate after heat aging by an air heating aging test (120 ° C., 336 hours) , Elongation (E _B ) retention rate, 5) Degree of swelling (oil resistance) according to oil resistance deterioration test (immersion test, 120 ° C, 72 hours) 6) α ₁ , α ₂ (α ₁ , α ₂ ) Where φ is the volume fraction, η is the melt viscosity, A, B, C
Represents the components (A), (B) and (C), respectively. α ₁ = (φ _{B + C} / φ _A ) / (η _A / η _{B + C} ) <1 α ₂ = (φ _B / φ _C ) / (η _C / η _B ) <1 where φ and η are It was determined by the method described below. ) Was measured and evaluated. Here, the low-temperature physical properties measured by the embrittlement test (−40 ° C.) were evaluated in two stages of ○ and ×.は indicates no abnormality, and × indicates crack generation or breakage. The volume fraction φ φ _A was obtained as follows. _{φ A = ((W A /} ρ A) / (W A / ρ A + W B / ρ B +
W _C / ρ _C )) × 100 where φ _A is the volume fraction of _A , W _A , W _B , and W _C are the compounding weights of the components (A), (B), and (C), ρ _A ,
ρ _B and ρ _C represent the densities of the components (A), (B), and (C), respectively, and here, the density at room temperature was used. Melt viscosity η Here, melt viscosity refers to the melt viscosity of any temperature and component during kneading, and the melt viscosity of each polymer material depends on temperature, shear rate (sec ^-1 ) and shear stress. For this reason, the stress and shear rate of the polymer material are generally measured at an arbitrary temperature in a molten state flowing through the narrow tube, particularly at a temperature range during kneading, and the melt viscosity is measured by the following equation.

(Equation 1) The melt viscosity was measured using a capillary rheometer Capillograph 1C manufactured by Toyo Seiki Co., Ltd. The evaluation results are shown in Table 1 below. In the table, the amounts of the components are expressed in parts by weight.

[0037]

[Table 1]

[0038]

[0039]

[Table 2]

[0040]

The compounds used in the examples and comparative examples are as follows. AEM1: Esprene EMA 2752 (epoxy group-containing ethylene-acrylate copolymer, manufactured by Sumitomo Chemical Co., Ltd.) AEM2: Vamac G (carboxyl group-containing ethylene-acrylate copolymer, manufactured by DuPont) NBR: Perbunan NT2865 (acrylonitrile) -Butadiene rubber, manufactured by Bayer Co., Ltd. PA6: Amilan CM1001 (polyamide resin, manufactured by Toray Industries, Inc.) PA6-66: UBE Nylon 5013B (polyamide resin, manufactured by Ube Industries, Ltd.) Antiaging agent: Irganox1010 (Nihon Ciba Geigy) Processing aid: Armin 18D (Lion Akzo Co., Ltd.)
Peroxide: Kayahexa YD (Kyaku Akzo Co., Ltd.)
Sulfur: powdered sulfur (made by Karuizawa Seirensho Co., Ltd.) Phenol resin: Tackirol 250-I (made by Taoka Chemical Industry Co., Ltd.) Zinc flower: Zinc flower No. 3 (made by Seido Chemical Co., Ltd.) Stearic acid: beads Stearic acid (Nippon Oil & Fats Co., Ltd.)
Maleic acid-modified PP: Admer QB540 (maleic acid-modified polypropylene, manufactured by Mitsui Petrochemical Industries, Ltd.)

[0042] (Examples 10 to 12, Comparative Example 6, the conventional example) as the inner tube material as shown in Preparation Table 2 of the hose, Examples 2 and 4, Comparative Example 4, 3 or acrylonitrile butadiene rubber on a mandrel After extrusion, brass-plated wire (diameter 0.25 mm) was braided into a braid to form a reinforcing layer. Thereafter, an outer pipe material made of EPDM / PP thermoplastic elastomer (Santoprene 101-73, AES) or a material of Example 8 and chloroprene (CR) rubber was extruded thereon to form a hose. Example 1
0 to 12, Comparative Example 6, and Conventional Example. Examples 10-1
2. In Comparative Example 6, maleic acid-modified polypropylene (Admer QB540, manufactured by Mitsui Petrochemical Co.) was used as an adhesive between the inner tube and the reinforcing layer and between the reinforcing layer and the outer tube. Also,
For the conventional example, after molding, 150 ° C., 20 kg / cm
^The vulcanization treatment was carried out at ² for 45 minutes. N used in the conventional example
The compositions of BR and CR are shown below.

Composition of NBR NBR (Nipol 1042 manufactured by Zeon Corporation) 100 SRF carbon black 90 zinc white 5 stearic acid 1 antioxidant OD 1 plasticizer DOP 10 sulfur 2 accelerator TS 1 CR composition Neoprene W 100 SRF carbon black Reference Signs List 60 stearic acid 1 magnesium oxide (MgO) 4 antioxidant OD 2 softener (Fucor 1150N) 10 zinc white 5 accelerator TU 0.75

The hose manufactured by the above method has an inner diameter of 9.
5 mm, the thickness of the inner tube and the outer tube is 1.5 mm, respectively.
1.0 mm.

Evaluation of Physical Properties of Hose The hoses of Examples 10 to 12, Comparative Example 6, and the conventional example were measured and evaluated for the following physical properties in accordance with JIS K6330. 1) Impulse test (durability) Use auto-multi oil (made by Idemitsu Kosan Co., Ltd.) as oil.
Repeated impact pressures were applied under the conditions of 00 ° C. and a pressure of 140 kg / cm ² , and after 1 million shocks, the test was interrupted if no abnormality occurred and the test was evaluated as ○. 2) Flexibility The hose was bent along an arc having a predetermined radius, and the bending force was measured. The bending radius is 10 times the outer diameter of the hose (10
The measurement was started from D), and the bending force was sequentially measured up to three times (n = 2). From the curve obtained by plotting the relationship between the bending force and the bending radius obtained as a result, a method of reading a numerical value at a specified radius (4 times) was adopted. The data were expressed as relative values, with the value of the hose produced in the conventional example being 100, and the load at which the hoses of the examples and comparative examples were similarly deformed. The smaller the value, the higher the flexibility.

3) Man-hours The man-hours for manufacturing the hose of the conventional example were set to 100, and the man-hours for manufacturing the hoses of the example and the comparative example were expressed as relative values. Manufacturing of a conventional hose requires a process of vulcanizing under heat and pressure after forming the hose on a mandrel, but the hose of the present invention has a fine crosslinked rubber phase in a thermoplastic resin phase by dynamic crosslinking. Since a hose is formed using the dispersed composition, a vulcanization step after hose molding is not required. The man-hours for manufacturing the hose of the present invention were 80 compared to 100 for the conventional example. 4) Low temperature properties An embrittlement test was performed at -40 ° C in accordance with JIS K6301. The data were expressed as relative values, with the value of the hose produced in the conventional example as 100. The lower the value, the better the low-temperature properties.

[0047]

[0048]

According to the present invention, a thermoplastic elastomer composition having good flexibility, low temperature properties, high temperature properties, heat aging resistance and oil resistance can be obtained. Further, according to the present invention, a hose excellent in oil resistance, heat aging resistance and low-temperature physical properties can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a hose of the present invention.

FIG. 2 is a diagram showing an example of a method for manufacturing a hose of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hose 2 Inner tube 3 Reinforcement layer 4 Outer tube 5, 6 Adhesive layer 7 Mandrel 8 Extruder for inner tube material 9 Extruder for adhesive 10 Die for forming inner tube 11 Inner tube 12 Reinforcing layer forming machine 13 Reinforcing layer 14 Heating device 15 Die for forming outer tube 16 Extruder for adhesive 17 Extruder for outer tube material 18 Outer tube

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Susumu Hatanaka 2-1 Oiwake, Hiratsuka City, Kanagawa Prefecture Inside of Yokohama Rubber Co., Ltd. Hiratsuka Factory

Claims (6)

[Claims] 1. A thermoplastic polyamide resin having a continuous phase (A)
Wherein the dispersed phase is an acrylonitrile-butadiene rubber (B) and an ethylene-acrylate copolymer rubber (C), wherein the thermoplastic elastomer composition is dynamically crosslinked. 2. The composition ratio (weight ratio) of the components (A) and (B) + (C) (A) / (B) + (C) is from 70/30.
The thermoplastic elastomer composition according to claim 1, which is 20/80. 3. The thermoplastic elastomer composition according to claim 1, wherein the composition ratio (weight ratio) (B) / (C) of the components (B) and (C) is from 10/90 to 90/10. Stuff. 4. The thermoplastic elastomer composition according to claim 1, wherein said component (C) is a multicomponent copolymer with an epoxy group-containing crosslinkable monomer. 5. The composition according to claim 1, wherein said component (C) is a multi-component copolymer with a carboxyl-containing crosslinkable monomer.
The thermoplastic elastomer composition according to any one of the above. 6. A hose containing at least the thermoplastic elastomer composition according to claim 1 in an inner tube.