JP2000290483A - Thermoplastic elastomer composition and hose using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic elastomer composition capable of improving the flexibility (normal temperature and low temperature), oil resistance and freeze resistance of hose when used in an inner tube and/or an outer tube of hose and reducing a production cost due to production without requiring a vulcanization process and to provide a hose having the above-mentioned characteristics by using the composition in the inner tube and/or the outer tube. SOLUTION: This thermoplastic elastomer composition comprises (i) 30-90 wt.% of a thermoplastic resin composition containing a thermoplastic copolyester elastomer consisting of a high-melting crystalline polymer hard segment and a low-melting polymer soft segment and (ii) 10-70 wt.% of a rubber composition composed of an acrylic rubber containing an acrylic group and an epoxy group (100 wt.% of the total of the component (i) and the component (ii). This hose is obtained by using the thermoplastic elastomer composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic elastomer composition and a hose using the same, and more particularly to a thermoplastic resin composition containing a thermoplastic copolyester elastomer and a rubber composition containing a specific acrylic rubber. When used as an inner tube and / or outer tube of a hose, it can be manufactured with excellent oil resistance, cold resistance and heat resistance and without the need for a vulcanization step, and has flexibility without reducing durability. The present invention relates to an improved thermoplastic elastomer composition and a hose using the same.

[0002]

2. Description of the Related Art A rubber hose usually comprises an inner tube, a reinforcing layer, and an outer tube, and the inner tube and the outer tube are made of vulcanized rubber. However, such a rubber hose requires a vulcanization step. There is a problem that the manufacturing process becomes complicated.
On the other hand, there is also known a so-called resin hose in which the inner tube and the outer tube are made of a thermoplastic resin and the production process is simple in that a vulcanization process is not required. However, the thermoplastic resin constituting the resin hose is generally harder than the vulcanized rubber, and it is difficult to obtain a flexible hose, and the thermoplastic resin has a softening point, usually at 120 ° C. or higher. Was also difficult to use.

In order to improve the flexibility of a thermoplastic resin, a resin hose having an inner tube made of a polyester-based thermoplastic elastomer having a hard segment of polybutylene terephthalate and a soft segment of polytetramethylene glycol or polycaprolactone. As is also known, this polyester-based thermoplastic elastomer,
There is a limit in reducing the hardness in order to obtain the necessary heat-resistant softening properties and strength properties, and a hose having sufficient flexibility and heat resistance, such as vulcanized rubber, has not been obtained.

[0004] Therefore, a hose having sufficient flexibility which can be manufactured in a simple process which does not require a vulcanization process and a hose which has heat resistance which can be used for pressure transmission at high temperatures and fluid transport, etc. Development was desired. In response to such a demand, a hose having an inner tube and an outer tube formed of a thermoplastic elastomer in which a vulcanized rubber is dispersed in a thermoplastic resin has been proposed (see Japanese Patent Application No. 6-64102). .

This hose has an inner tube made of a thermoplastic elastomer in which a vulcanized composition of an acrylic group-containing rubber is dispersed in a polyester-based thermoplastic resin, and has a thermoplastic resin in which a vulcanized rubber is dispersed in a thermoplastic resin. The outer tube is composed of an elastomer. Further, the reinforcing layer is formed by adhering an organic fiber such as rayon fiber, polyester fiber or hard wire or an inorganic wire to the inner tube and the outer tube via a room-temperature-curable urethane-based adhesive or the like. However, such hoses have not always been practically satisfactory in low-temperature properties, especially flexibility and cold resistance at low temperatures, and furthermore, improvement in oil resistance was required.

Therefore, the flexibility of the hose at low temperatures,
For the purpose of further improving oil resistance and cold resistance,
JP-A-9-272788 proposes a thermoplastic elastomer composition containing a thermoplastic copolyester elastomer and an acrylic rubber containing an acrylic group and an epoxy group.

[0007]

With the above construction, a hose having good flexibility, oil resistance and cold resistance at low temperatures can be obtained, but if such a hose also has sufficient flexibility and durability. Nevertheless, further improvements were needed.

Accordingly, an object of the present invention is to provide a thermoplastic elastomer composition capable of improving the flexibility and durability of a hose when used for the inner tube and / or the outer tube of a hose, and a thermoplastic elastomer composition comprising the same. Another object of the present invention is to provide a hose having the above characteristics used for an outer tube.

[0009]

According to the present invention, (i)
30 to 90% by weight of a thermoplastic resin composition containing at least one thermoplastic copolyester elastomer, and (ii)
The thermoplastic copolyester elastomer (i) contains 10 to 70% by weight of a rubber composition containing an acrylic rubber containing an acrylic group and an epoxy group (provided that the total amount of the components (i) and (ii) is 100% by weight). The main components are a high-melting crystalline polymer hard segment containing a crystalline aromatic polyester and a low-melting polymer soft segment containing an aromatic and / or aliphatic polyester unit containing an aliphatic polyether. A thermoplastic elastomer composition, wherein the molar ratio of the polyol residue of the hard segment to the polyol residue of the soft segment is 1: 1.5 or more and less than 4.0, And / or a hose used for the outer tube is provided. As described above, by using the specific thermoplastic copolyester elastomer, the flexibility can be further improved while maintaining the durability of the hose.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic elastomer composition constituting the inner tube and the outer tube of the hose of the present invention refers to a thermoplastic resin composition containing a thermoplastic copolyester elastomer in an amount sufficient to impart thermoplasticity. A thermoplastic copolyester elastomer component forms a continuous phase (matrix phase) in which at least a portion of the rubber sufficient elasticity is blended with a rubber composition containing a vulcanized acrylic rubber. It refers to the presence of at least partially vulcanized acrylic rubber as a discontinuous phase (dispersed phase).
In addition, what is called a salami structure in which a thermoplastic resin is further dispersed in the discontinuous phase (rubber phase) may be used.

The thermoplastic copolyester elastomer, which is the first component of the thermoplastic elastomer composition of the present invention, is a multi-block copolymer containing a polyester and a polyether as main repeating units. A high-melting-point crystalline polymer hard segment and a low-melting-point polymer soft segment containing an aromatic and / or aliphatic polyester unit containing an aliphatic polyether as main components, and a polyol of the hard segment. The molar ratio of the residue to the polyol residue of the soft segment is 1: 1.5 or more and less than 4.0.

[0012] The high melting crystalline polymer hard segment containing the crystalline aromatic polyester of the thermoplastic copolyester elastomer (i) used in the present invention is mainly composed of an aromatic dicarboxylic acid or an ester-forming derivative thereof, a diol or A polyester formed from the ester-forming derivative.

The aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, anthracene dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, Diphenoxyethanedicarboxylic acid, 4,4'-
Examples include diphenyl ether dicarboxylic acid, 5-sulfoisophthalic acid, and sodium 3-sulfoisophthalate. Although an aromatic dicarboxylic acid is mainly used, if necessary, a part of the aromatic dicarboxylic acid is replaced with 1,4-cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid,
It may be substituted with an alicyclic dicarboxylic acid such as 4,4'-dicyclohexyldicarboxylic acid, or an aliphatic dicarboxylic acid such as adipic acid, succinic acid, oxalic acid, sebacic acid, dodecandioic acid, or dimer acid. Of course, ester-forming derivatives of dicarboxylic acids, for example, lower alkyl esters, aryl esters, carbonates, acid halides and the like can be equally used.

Examples of the diol include diols having a molecular weight of 400 or less, for example, aliphatic diols such as 1,4-butanediol, ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol, and the like. Alicyclic diols such as 1,1-cyclohexanedimethanol, 1,4-dicyclohexanedimethanol, tricyclodecanedimethanol, xylylene glycol,
Bis (p-hydroxy) diphenyl, bis (p-hydroxyphenyl) propane, 2,2-bis [4- (2-hydroxyethoxy) phenyl] propane, bis [4-
(2-hydroxy) phenyl] sulfone, 1,1-bis [4- (2-hydroxyethoxy) phenyl] cyclohexane, 4,4′-dihydroxy-p-terphenyl,
Aromatic diols such as 4,4'-dihydroxy-p-quarterphenyl are preferred, and such diols can also be used in the form of an ester-forming derivative, for example, an acetyl form or an alkali metal salt.

These dicarboxylic acids and their derivatives or diol components may be used in combination of two or more. The most preferred example of the high melting crystalline polymer segment (a) is terephthalic acid and / or dimethyl terephthalate,
Polybutylene terephthalate derived from 4-butanediol.

The low melting point polymer soft segment constituting the thermoplastic copolyester elastomer (i) of the present invention contains aromatic and / or aliphatic polyester units containing an aliphatic polyether.

Examples of the aliphatic polyether include poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol,
Examples include a copolymer of ethylene oxide and propylene oxide, an ethylene oxide addition polymer of poly (propylene oxide) glycol, and a copolymer of ethylene oxide and tetrahydrofuran. By containing such an aliphatic polyether, rubber elasticity can be imparted to the thermoplastic copolyester elastomer, and flexibility can be improved without impairing the mechanical properties of the thermoplastic elastomer composition.

Examples of the aromatic polyester include those similar to the above-described crystalline aromatic polyester of the high-melting crystalline polymer hard segment.

Examples of the aliphatic polyester include poly (ε-caprolactone), polyenanthractone, polycaprylolactone, polybutylene adipate and the like.

Poly (tetramethylene oxide) glycol, poly (propylene oxide) glycol can be obtained from the elastic properties of the polyester block copolymer obtained from the aromatic and / or aliphatic polyester units containing these aliphatic polyethers. Ethylene oxide adduct, poly (ε-caprolactone), polybutylene adipate and the like are preferred.

The copolymerization amount of the soft segment of the low melting point polymer in the thermoplastic copolyester elastomer (i) used in the present invention is expressed by a molar ratio of the polyol segment of the hard segment to the polyol segment of the soft segment as 1: 1.5 or more and less than 4.0, preferably 1:
1.6 to 1.8. Soft segment ratio of 1: 1.
If it is smaller than 5, the effect of improving flexibility is not obtained, and if it is more than 1: 4.0, physical properties such as mechanical strength are reduced and durability of a hose or the like is deteriorated.

Further, (i) a thermoplastic resin other than the thermoplastic copolyester elastomer can be appropriately blended with the thermoplastic resin composition containing at least one thermoplastic copolyester elastomer. It is preferable to contain the polyester elastomer in an amount of 50% by weight or more.

The acrylic rubber used as a rubber component of the thermoplastic elastomer composition of the present invention is a crosslinkable rubber having an acrylic group and an epoxy group as a main chain or a side chain in a molecule. A copolymer rubber containing acrylate and / or methacrylate as a copolymer component can be given. The epoxy group-containing (meth) acrylate copolymer or the epoxy group-containing (meth) acrylate copolymer rubber used in the present invention comprises (1) alkyl (meth) acrylate and / or alkoxy (meth) acrylate substitution. A multicomponent copolymer obtained by polymerizing an alkyl ester, (2) an epoxy group-containing monomer, and (3) another ethylenically unsaturated monomer copolymerizable with these (1) and (2), if necessary. It is a polymer rubber.

The alkyl (meth) acrylate (1) used for producing the epoxy group-containing (meth) acrylate copolymer rubber has the following formula:

[0025]

Embedded image (In the formula, R ₁ is an alkyl group having 1 to 18 carbon atoms, R ₂
Represents hydrogen or a methyl group). Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and n- Pentyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-methylpentyl (meth) acrylate, n-
Octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, n- octadecyl (meth) acrylate, and the like, among which ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate,
n-Octyl (meth) acrylate is preferred. More preferably, low-temperature characteristics can be further improved by using an acrylic rubber containing an alkyl ester portion in which R ₁ is C _{3 to} C ₁₈ by 25% by weight or more of the acrylic rubber.

The alkoxy-substituted alkyl (meth) acrylate (1) has the following formula:

[0027]

Embedded image (Wherein, R ₃ is hydrogen or a methyl group, R ₄ is C 1-18)
And R ₅ represents an alkyl group having 1 to 18 carbon atoms). Specific examples of the alkyl (meth) acrylate include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (n-propoxy) ethyl (meth) acrylate, and 2- (n- Butoxy) ethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 3
-Ethoxypropyl (meth) acrylate, 2- (n-
Propoxy) propyl (meth) acrylate, 2- (n
-Butoxy) propyl (meth) acrylate and the like.

Examples of the epoxy group-containing monomer used in the production of the epoxy group-containing (meth) acrylate copolymer rubber include allyl glycidyl ether, glycidyl methacrylate, glycidyl acrylate, and the compounds shown below (each of the following formulas). Wherein R ₆ in the formula represents hydrogen or a methyl group).

[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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If necessary, 2-cyanoethyl (meth) acrylate may be used as a monomer to be copolymerized with the alkyl (meth) acrylate or the alkoxy-substituted alkyl (meth) acrylate (1) and the epoxy group-containing monomer. A) cyano-substituted alkyl (meth) acrylates such as acrylate, 3-cyanopropyl (meth) acrylate and 4-cyanobutyl (meth) acrylate; amino-substituted alkyl (meth) acrylates such as diethylaminoethyl (meth) acrylate; Fluorine-containing (meth) such as 1-trifluoroethyl (meth) acrylate
Acrylates, hydroxy-substituted alkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, alkyl vinyl ketones such as methyl vinyl ketone, vinyl or allyl ethers such as vinyl ethyl ether, allyl methyl ether, styrene, α-methyl styrene,
Examples include vinyl aromatic compounds such as chlorostyrene and vinyl toluene, vinyl nitriles such as acrylonitrile and methacrylonitrile, vinyl amides such as acrylamide, methacrylamide, and N-methylol acrylamide, and ethylene, propylene, and vinyl acetate. Acrylic rubber used in the present invention is preferably an acrylic rubber alkyl moiety and acrylic acid is from alkyl esters of C ₃ -C _18, such as butyl acrylate, propyl acrylate, dodecyl acrylate,
Hexadecyl acrylate is contained in an amount of 25% by weight or more, more preferably 30 to 60% by weight.

As a specific component constitution of the rubber containing an acrylic group and an epoxy group (acrylic rubber), from the viewpoint of heat resistance, an alkyl (meth) acrylate or an alkoxyalkyl (meth) acrylate (1) is ethyl. A copolymer rubber composed of acrylate alone and glycidyl methacrylate as an epoxy group-containing monomer is an alkyl (meth) acrylate or an alkoxyalkyl (meth) acrylate (1) from the viewpoint of cold resistance.
A preferred example is a copolymer rubber composed of ethyl acrylate, butyl acrylate and methoxyethyl acrylate, and glycidyl methacrylate as an epoxy group-containing monomer. Furthermore, in terms of balance between heat resistance and cold resistance, alkyl (meth) acrylate or alkoxyalkyl (meth) acrylate (1)
It is better to select the type and amount of In addition, the epoxy group-containing monomer component is used for the crosslinking reaction of the epoxy group in the crosslinking of the copolymer rubber, and is usually 1 to 20% by weight, preferably 1.5 to 15% by weight, more preferably , 2
The one containing 10% by weight is suitably used in the vulcanization reactivity dynamically performed during kneading described later.

The thermoplastic elastomer composition of the present invention comprises:
A thermoplastic elastomer composition (i) containing a thermoplastic copolyester elastomer and a rubber composition (ii) containing an acrylic rubber were mixed with component (i): component (ii) = 30 to 90% by weight: 70 to 10% by weight ( 100% by weight in total), preferably component (i): component (ii) = 30 to 80% by weight: 70 to
It is blended at 20% by weight. If the compounding amount of the component (i) is too large, the flexibility is impaired, which is not preferable. On the contrary, if it is too small, the mechanical strength is reduced and the rubber phase becomes a matrix phase and the fluidity at the time of extrusion is impaired. It is not preferable.

The thermoplastic elastomer composition of the present invention includes a crosslinking agent compound or an organic peroxide having at least one of a carboxyl group and a carboxylic anhydride group as a carboxyl group in the molecule.
Typical examples of such a crosslinking agent compound include, for example, the following compounds.

The crosslinking agent of the present invention is not particularly limited as long as it is a compound having two or more carboxyl groups and / or one or more carboxylic anhydride groups in the molecule. Preferably, aliphatic, cycloaliphatic and aromatic polycarboxylic acids, their (partial) carboxylic anhydrides, and (partial) esterified products of these compounds with (poly) alkylene glycols are used. As the crosslinking agent, those having a molecular weight of 5,000 or less are preferable.

Specific examples of the aliphatic polycarboxylic acid include:
Examples include succinic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, dodecenylsuccinic acid, and butanetetracarboxylic acid. Specific examples of the alicyclic polycarboxylic acid include cyclopentane dicarboxylic acid, cyclopentane tricarboxylic acid, cyclopentane tetracarboxylic acid, cyclohexane dicarboxylic acid, cyclohexane tricarboxylic acid, methyl cyclohexane dicarboxylic acid, tetrahydrophthalic acid, endomethylene tetrahydrophthalic acid And methylendomethylenetetrahydrophthalic acid.
Specific examples of the aromatic polycarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, and pyromellitic acid. Specific examples of (partial) carboxylic acid anhydrides include (partial) carboxylic acid anhydrides of these polycarboxylic acids.

The preferred amount of the crosslinking agent compound is 0.5 to 2 per 100 parts by weight of the rubber composition containing the acrylic rubber.
0 parts by weight, more preferably 1 to 15 parts by weight. The addition of such a crosslinking agent compound is preferred because the acrylic rubber dispersed phase is crosslinked and the mechanical strength is improved and the set resistance is improved.

The elastomer composition or the thermoplastic resin composition may be used in order to improve the fluidity, heat resistance, physical strength and cost of the thermoplastic elastomer composition.
A necessary amount of a compounding agent such as a reinforcing agent, a filler, a softening agent, an antioxidant, or a processing aid, which is added to a usual composition, can be added as long as the object of the present invention is not impaired.

When the specific thermoplastic resin and the rubber composition have different chemical compatibility, it is preferable to use a suitable compatibilizer as the third component to make them compatible.
By mixing the compatibilizer into the system, the interfacial tension between the thermoplastic resin and the rubber composition is reduced, and as a result, the particle diameter of the rubber composition forming the dispersion layer becomes fine, so that both components are dispersed. The properties will be more effectively expressed. As such a compatibilizer generally a thermoplastic resin component, a copolymer having a structure of both or one of the rubber components, or an epoxy group capable of reacting with the thermoplastic resin component or the rubber component,
The copolymer may have a structure having a carboxyl group, a carbonyl group, a halogen group, an amino group, an oxazoline group, a hydroxyl group, and the like. These may be selected depending on the types of the thermoplastic resin component and the rubber component to be mixed, and commonly used ones include styrene-ethylene-butylene-styrene-based block copolymer (SEBS) and its maleic acid-modified product, EPDM, EPM and their modified maleic acid, EPDM / styrene or EPDM /
An acrylonitrile graft copolymer and its maleic acid-modified product, a styrene / maleic acid copolymer, a maleic acid or epoxy-modified ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate, and a reactive phenoxine can be given. The amount of such a compatibilizer is not particularly limited, but is preferably 0.5 to 20 parts by weight based on 100 parts by weight of the polymer component (total of thermoplastic resin and rubber).

The vulcanizing agent, vulcanization aid and vulcanization conditions (temperature, time) used for vulcanization of the rubber composition used in the thermoplastic elastomer composition used in the present invention are determined by the rubber composition to be added. What is necessary is just to determine suitably according to the composition of a product, and there is no restriction in particular. As the vulcanizing agent, a general rubber vulcanizing agent (crosslinking agent) can be used. 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. About 4 phr (parts by weight per 100 parts by weight of the elastomer component (polymer)) may be used.

The organic peroxide-based vulcanizing agents include:
Benzoyl peroxide, t-butyl hydroperoxide, 2,4-dichlorobenzoyl peroxide,
Examples thereof include 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and 2,5-dimethylhexane-2,5-di (peroxylbenzoate).
About 1 to 15 phr may be used. Further, examples of the phenolic resin-based vulcanizing agent include bromide of an alkylphenol resin, a mixed crosslinking system containing a halogen donor such as tin chloride or chloroprene and an alkylphenol resin, and for example, about 1 to 20 phr is used. I just need.

Others include zinc white (about 5 phr),
Magnesium oxide (about 4 phr), litharge (10 to 10 phr)
About 20 phr), p-quinone dioxime, p-dibenzoylquinone dioxime, tetrachloro-p-benzoquinone, poly-p-dinitrosobenzene (2 to 10 phr)
Degree) and methylin dianiline (about 0.2 to 10 phr).

If necessary, a vulcanization accelerator may be added. Examples of the vulcanization accelerator include common vulcanization accelerators such as aldehyde / ammonia, guanidine, thiazole, sulfenamide, thiuram, dithioate, and thiourea, for example, 0.5 to 2 phr. The degree may be used.

Specifically, hexamethylenetetramine and the like are used as the aldehyde / ammonia vulcanization accelerator; diphenylguanidine and the like are used as the guanidine vulcanization accelerator; dibenzothia is used as the thiazole vulcanization accelerator. Zirdisulphide (DM), 2-mercaptobenzothiazole and its Zn salt, cyclohexylamine salt and the like; as a sulfenamide vulcanization accelerator, cyclohexylbenzothiazylsulfenamide (CBS);
N-oxydiethylenebenzothiazyl-2-sulfenamide, Nt-butyl-2-benzothiazolesulfenamide, 2- (thymolpolynyldithio) benzothiazole and the like; , Tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide (TMTM), dipentamethylenethiuram tetrasulfide, etc .; Zn-
Thiourea such as diethyldithiocarbamate, Zn-di-n-butyldithiocarbamate, Zn-ethylphenyldithiocarbamate, Tc-diethyldithiocarbamate, Cu-dimethyldithiocarbamate, Fe-dimethyldithiocarbamate, pipecoline pipecolyldithiocarbamate and the like; Examples of the vulcanization accelerator include ethylenethiourea, diethylthiourea and the like;

As the vulcanization accelerator, general rubber auxiliaries can be used in combination.
phr), stearic acid, oleic acid, and Zn salts thereof (about 2 to 4 phr) may be used.

In the rubber composition (ii) containing an acrylic rubber containing an acrylic group and an epoxy group, a rubber other than the acrylic rubber containing an acrylic group and an epoxy group can be appropriately compounded. It is preferable to contain 50% by weight or more of an acrylic rubber containing an acrylic group and an epoxy group.

The method for producing the thermoplastic elastomer composition used in the present invention comprises the steps of preparing a thermoplastic resin component containing a thermoplastic copolyester elastomer and a rubber composition containing an acrylic rubber containing an acrylic group and an epoxy group in advance.
By melt-kneading with a shaft kneading extruder or the like, and dispersing the rubber composition as a dispersed phase (domain) in a thermoplastic resin forming a continuous phase (matrix phase). Next, in order to vulcanize the rubber composition, a vulcanizing agent is added under kneading to dynamically vulcanize the rubber composition. Further, various compounding agents for the thermoplastic resin or the rubber composition may be added during the kneading, but it is preferable to mix them beforehand before the kneading. At this time, a vulcanizing agent may be mixed in the rubber composition in advance, and vulcanization may be simultaneously performed during kneading of the thermoplastic resin and the rubber composition. The kneading machine used for kneading the thermoplastic resin and the rubber composition is not particularly limited, and a screw extruder, a kneader, a Banbury mixer, a twin-screw kneading extruder and the like can be used. Among them, it is preferable to use a twin-screw kneading extruder for kneading the thermoplastic resin and the rubber composition and for dynamic vulcanization of the rubber composition. Further, two or more types of kneaders may be used to knead sequentially.

By utilizing such a manufacturing method, the obtained thermoplastic elastomer composition has a vulcanized rubber phase at least partly a discontinuous phase and a thermoplastic resin phase at least partly a discontinuous phase. Because it is in a finely dispersed state, this thermoplastic elastomer composition shows the same behavior as vulcanized rubber, and since at least the continuous phase is a thermoplastic resin phase, the thermoplastic resin Processing according to is possible.

Such a thermoplastic elastomer composition comprises at least a part of a thermoplastic resin as a continuous phase and at least a part of a rubber composition as a discontinuous phase, and comprises a vulcanized rubber composition which is a discontinuous phase. The particle diameter is preferably 50 μm or less, and more preferably 0.1 to 10 μm.

The kneading conditions, the type of vulcanizing agent used,
The amount and vulcanization conditions (temperature, etc.) may be appropriately determined according to the blending of the rubber composition to be added and the blending amount of the rubber composition.
There is no particular limitation.

A method for producing such a thermoplastic elastomer composition of the present invention will be described below. In the production of the thermoplastic elastomer composition of the present invention, first, a resin and a rubber composition are added, melt-kneaded, and then a vulcanizing agent is added under kneading,
This can be done by dynamically vulcanizing the rubber.

The composition of the present invention may contain additives such as a reinforcing agent, a softening agent and an antioxidant, if necessary. The compounding agent for the rubber composition may be added during the kneading, but the compounding agent other than the vulcanizing agent is preferably mixed in advance before the kneading. The compounding agent for the resin composition may be previously mixed before the kneading, or may be added during the kneading.

The kneading machine used for producing the thermoplastic elastomer composition of the present invention is not particularly limited, and examples thereof include a screw extruder, a kneader, a Banbury mixer, and a twin-screw kneading extruder. Among these, it is preferable to use a twin-screw kneading extruder in consideration of kneading of the resin component and the rubber component and dynamic vulcanization of the rubber component. Further, two or more types of kneaders may be used to knead sequentially.

The conditions for the melt-kneading are, for example, a kneading temperature of preferably from 90 to 350 ° C., particularly preferably from 180 to 300 ° C., provided that the temperature is not lower than the temperature at which the thermoplastic copolyester elastomer component melts. Not done. If the kneading temperature is less than 90 ° C., the vulcanization time will be delayed, and if it exceeds 350 ° C., the physical properties of the thermoplastic elastomer composition will be reduced due to decomposition of the polymer. The shear rate during kneading is 500 to 8000 sec ^-1 ,
It is preferably from 00 to 5000 sec ^-1 . The retention time of the entire melt kneading is preferably 30 seconds to 10 minutes, and the retention time (vulcanization time) after the addition of the vulcanizing agent is preferably 15 seconds to 5 minutes. The shear rate is calculated by dividing the product obtained by multiplying the circumference of the circle drawn by the screw tip by the number of revolutions of the screw for one second by the gap at the tip. That is, the shear rate is
This value is obtained by dividing the tip speed by the tip gap. Here, the residence time in the part where dynamic vulcanization is performed is calculated by multiplying the total volume of the part where dynamic vulcanization is performed by the filling factor and dividing the result by the volume flow rate.

When the thermoplastic elastomer composition is produced by such a production method, the relationship between the viscosity and the volume fraction of the thermoplastic resin composition and the acrylic rubber composition to be used at the time of melt-kneading are interrelated. Normal kneading temperature 90 ℃ -3
In the range of 50 ° C. and the shear rate of 500 to 8000 sec ⁻¹ , it is preferable that the following relationship be satisfied. 0.25 ≦ φ ₁ ≦ 0.90, preferably 0.30 ≦ φ ₁
≦ 0.80 0.10 ≦ φ ₂ ≦ 0.75, preferably 0.20 ≦ φ ₂
≦ 0.70 φ ₁ + φ ₂ = 1.0 η ₂ / η ₁ <4.0, preferably <3.7 (η ₁ / η ₂ ) (φ ₂ / φ ₁ ) <1.0 where η ₁ : Viscosity of the thermoplastic resin composition at the time of melt-kneading η ₂ : Viscosity of the rubber composition at the time of melt-kneading φ ₁ : Volume fraction of the thermoplastic resin composition φ ₂ : Volume fraction of the rubber composition By kneading within the range, the kneadability is stabilized, the rubber ratio is controlled widely, and it is possible to achieve a high rubber ratio, and it is possible to obtain a thermoplastic elastomer composition that is flexible and has high elongation at break. it can.

Here, the melt viscosity means an arbitrary temperature and a melt viscosity of a component during kneading, and the melt viscosity of each polymer material depends on temperature, shear rate (sec ^-1 ) and shear stress. Therefore, the stress and shear rate of the polymer material are generally measured at an arbitrary temperature in a molten state flowing in the thin tube, particularly at a temperature range during kneading, and the melt viscosity is measured by the following equation (1).

[0065]

(Equation 1) The melt viscosity was measured using a capillary rheometer Capillograph 1C manufactured by Toyo Seiki Co., Ltd.

In order to manufacture the hose according to the present invention, the thermoplastic elastomer is used by a known extrusion molding to prepare the inner tube of the hose of the present invention, and an adhesive is applied to the outer surface thereof as necessary. After extruding the adhesive thermoplastic resin, wrap the reinforcing fiber or steel wire in a braided or spiral shape on top of it, and apply an adhesive as necessary, or extrude the adhesive thermoplastic resin, and then re-extrude the thermoplastic elastomer. A general method of coating the outer tube by extrusion molding can be used. At that time, the thermoplastic resin composition containing the above-mentioned thermoplastic copolyester elastomer in at least one of the inner tube and / or the outer tube is coated with an acrylic resin. A thermoplastic elastomer composition in which a vulcanized rubber composition is dispersed is used.

In manufacturing the hose according to the present invention, when an appropriate adhesive is used as an adhesive layer between the inner pipe and the reinforcing layer made of fiber or steel wire and between the reinforcing layer and the outer pipe, As the adhesive, a urethane-based adhesive generally used for hoses can be used. When an adhesive thermoplastic resin is used, a polyester copolymer resin or the like can be used. In any case, the thickness of the adhesive layer is not particularly limited, but is preferably 10 to 500 μm, respectively.

Next, as the reinforcing layer of the hose according to the present invention, organic fibers such as aromatic polyamide fibers such as nylon fibers, vinylon fibers, rayon fibers, polyester fibers, and aramid fibers which have been conventionally used for hoses are used. It is possible to use a metal reinforcing layer such as a hard steel wire, a brass-plated steel wire, a bronze-plated steel wire, a galvanized steel wire, etc., but polyester fibers are used in terms of economy, flexibility, strength, and modulus. More preferably used.

As described above, the hose according to the present invention comprises an inner tube, a reinforcing layer, and an outer tube in which the thermoplastic elastomer composition of the present invention is used for at least one of an inner tube and an outer tube. Accordingly, an adhesive layer may be further included between the reinforcing layers.

[0070]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but it goes without saying that the present invention is not limited to the following Examples. The evaluation method used in the following examples is as follows. Biaxial kneading By kneading with a biaxial kneading extruder, the thermoplastic copolyester elastomer is sufficiently kneaded to form a matrix,
Acrylic rubber has a domain structure and is taken in a strand shape. ○, acrylic rubber has a matrix, thermoplastic copolyester elastomer has a domain structure, and biaxial kneaded material is not taken in a strand shape. Is indicated by x. Hose bending force One end of the hose is fixed, the hose is bent, and the other end is pressed toward one end of the hose.
mm, the load applied to the other end of the hose (kg
f) was measured. The impact pressure test was performed in accordance with JIS K6379.
K2213 (turbine oil), using a mineral oil corresponding to two kinds, a rectangular wave having a maximum pressure of 27.5 MPa at an oil temperature of 120 ° C. was repeatedly applied 50,000 times, and then a maximum pressure of 27 at an oil temperature of 30 ° C. The square wave of 5.5 MPa was repeated 500 times, and the above steps at 120 ° C. and 30 ° C. were alternately repeated, and the number of times (ten thousand times) until the hose was broken was measured.

Examples 1 to 5 and Comparative Examples 1 to 5 Preparation of Thermoplastic Copolyester Elastomer The preparation of thermoplastic copolyester elastomer is generally known, for example, by the method described in JP-B-49-31558. Can be synthesized. Dimethyl terephthalate, 1,4-butanediol, polytetramethylalene glycol (PTMG) were used as raw materials, and tetra-n-butyl titanate was used as a catalyst. The temperature was raised to 250 ° C. for 100 minutes while stirring them. . Thereafter, the pressure was gradually reduced to 0.1 mmHg in 10 minutes,
Polycondensation was performed. After reacting under reduced pressure for 120 minutes, the mixture was extruded into water. Further, it was extruded with a rubber pelletizer and pelletized. The thermoplastic copolyester elastomers 1 to 6 and 8 obtained had a hard segment of a terephthalic acid / 1,4-butanediol copolymer and a soft segment of a terephthalic acid / tetramethylene glycol copolymer. Elastomer 7
Has a hard segment of terephthalic acid / 1,4-butanediol copolymer and a soft segment of terephthalic acid /
It is an ethylene glycol copolymer, and the molar ratio between the polyol segment of the hard segment and the polyol segment of the soft segment is adjusted by changing the amount of 1,4-butanediol, the molecular weight and the amount of PTMG, etc. Table 1 shows the molecular weight of the obtained thermoplastic copolyester elastomer and the molar ratio of the polyol residue.

[0072]

[Table 1]

Next, the blending amounts (parts by weight) shown in Table 2 below
The thermoplastic copolyester elastomers 1 to 8 obtained above, the rubber composition excluding the crosslinking agent and talc were previously kneaded into pellets, and the compatibilizer was sheared at a shear rate of 100.
0 sec ⁻¹ , the temperature was set at 230 ° C. The twin screw kneading extruder was charged from the first inlet and melt-kneaded.
A premixed cross-linking agent and talc were charged and kneaded from the second input port to dynamically cross-link the rubber composition and fix the dispersion of the rubber phase. Thereafter, the obtained thermoplastic elastomer composition was extruded into a strand from the tip of a twin-screw kneading extruder, cooled with water, cooled, and then pelletized with a resin pelletizer.

Next, using the thermoplastic elastomer composition obtained above for the inner tube and the outer tube, the inner tube (1 m thick) was used.
m), polyester fiber reinforcing layer and outer tube (0.5 m thick)
m), a hose having an inner diameter of 6 mm and an outer diameter of 9.5 mm was prepared. The adhesive used was Tylite 7411 moisture-curable urethane-based adhesive manufactured by Lord Far East Co. (each adhesive layer thickness: 25 μm). In order to evaluate the flexibility and durability of the obtained hose, measurement of a hose bending force and an impact pressure test were performed, and the results are shown in Table 2.

[0075]

[Table 2]

The components used in Examples and Comparative Examples are shown below. Compatibilizer: Bondfast 7L, manufactured by Sumitomo Chemical Co., Ltd. Crosslinking agent: butanetetracarboxylic acid Acrylic rubber: Monomer composition is ethyl acrylate 40
Acrylic rubber of 30% by weight, butyl acrylate 32% by weight, methoxyethyl acrylate 19% by weight, glycidylethyl acrylate 9% by weight FEF carbon black: SEAST SO, manufactured by Tokai Carbon Co., Ltd. Hindered phenolic antioxidant: Irganox 1
010, manufactured by Ciba Geigy Japan

In Comparative Examples 1 and 5, since the thermoplastic copolyester elastomer having a small soft segment amount was used as shown in the molar ratio of the polyol residue, the hose bending strength was large and the flexibility was poor. I understand. In Comparative Example 2, on the contrary, the amount of the soft segment is too large, so that the durability in the impact pressure test decreases. In Comparative Example 3, the amount of the resin was too large, and both the flexibility and the durability deteriorated. In Comparative Example 4, conversely, the amount of rubber was too large, and the thermoplastic copolyester elastomer could not have a matrix structure and could not be kneaded. On the other hand, the compositions and hoses used in Examples 1 to 5 all exhibited good kneading properties, flexibility, and durability.

[0078]

As described above, according to the present invention,
By using a specific acrylic rubber by using a thermoplastic elastomer composition containing a specific thermoplastic copolyester elastomer and an acrylic rubber having an epoxy group as an inner tube and / or an outer tube, oil resistance,
Excellent cold resistance and cross-linking of the rubber composition by dynamic cross-linking eliminates the need for a processing (vulcanization) step like a rubber hose, thus reducing manufacturing costs and further polymerizing a thermoplastic copolyester elastomer. By devising the structure, a hose with improved flexibility and durability can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 4F100 AK25A AK41A AK42A AK53A AL01A AL05A AL09A AN02A BA01 BA02 BA03 BA06 BA13 DG01 DH00B EJ05A GB90 JA04A JA11A JB05A JB07 JB16A JJ04 JK13 CF14 CF07 CF07 CF19W CF22W 4J029 AA03 AB01 AC03 AE01 BA03 BA05 BD07A BF25 BF28 BH02 CB05A CB06A CC06A HA01 HB01

Claims (3)

[Claims] (I) a thermoplastic resin composition containing at least one thermoplastic copolyester elastomer;
0% by weight and (ii) 10 to 70% by weight of a rubber composition containing an acrylic rubber containing an acrylic group and an epoxy group (provided that the total amount of components (i) and (ii) is 100% by weight), Copolyester elastomer (i)
The main components are a high melting crystalline polymer hard segment containing a crystalline aromatic polyester, and a low melting polymer soft segment containing an aromatic and / or aliphatic polyester unit containing an aliphatic polyether. And the molar ratio of the polyol residue of the hard segment to the polyol residue of the soft segment is 1:
A thermoplastic elastomer composition having a ratio of 1.5 or more and less than 4.0. 2. The thermoplastic composition according to claim 1, wherein a rubber component of the rubber composition is crosslinked and dispersed as a dispersed phase in a matrix phase of the thermoplastic resin composition containing the thermoplastic copolyester elastomer. Elastomer composition. 3. A hose comprising at least an inner tube, a reinforcing layer, and an outer tube of a hose comprising the thermoplastic elastomer composition according to claim 1 or 2.