JPH06107867A - Thermoplastic elastomer composition - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent in hardness, tensile strength, tensile elongation, compression set, thermal aging resistance, oil resistance and molding appearance by mixing a specified thermoplastic polyester elastomer with a rubber component in a specified mixing ratio. CONSTITUTION:1-98wt.% thermoplastic polyester elastomer having a hard segment component comprising an aromatic liquid crystal polyester (e.g. an elastomer prepared by reacting polyethylene glycol with naphthalenedicarboxylic acid, hydroquinone diacetate and p-hydroxybenzoic acid) and 99-2wt.% rubber component (e.g. NBR) are dynamically crosslinked desirably during kneading the rubber component.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermoplastic elastomer composition having improved flexibility and compression set without impairing the excellent mechanical properties, heat resistance and oil resistance of polyester elastomer.

[0002]

2. Description of the Related Art Thermoplastic polyester elastomers are
It is composed of polyester and a polyether repeating unit, or polyester and a multi-block copolymer having the same in the polymer main chain, and is excellent in mechanical properties, heat resistance and oil resistance.

As described above, the thermoplastic polyester elastomer has excellent characteristics, but as an elastomer, it has a drawback of high hardness and poor flexibility. Also,
It has a large compression set, and its expansion is restricted. As a method of improving such a defect, a method of blending a polystyrene type block copolymer to soften it (Japanese Patent Laid-Open No. Sho 82-82162) and a method of blending an ethylene copolymer to soften it (Japanese Patent Laid-Open No. Sho 60-7662) has been proposed. However, the flexibility of the polyester elastomer obtained by these methods is still insufficient and there is a drawback that the oil resistance is lowered.

Also, as is done with normal rubber,
A method has been proposed in which flexibility, oil resistance and heat resistance are made compatible by adding a crosslinking agent on a rubber roll containing a vulcanizable rubber and then vulcanizing it (Japanese Patent Publication No. 55-35057). However, in this method, the temperature at which the crosslinking agent is added is significantly lower than the melting point of the polyester elastomer, so it is difficult to sufficiently disperse and knead the crosslinking agent, and it is difficult to obtain a stable composition in actual production. Is. Furthermore, oil resistance and heat resistance are still insufficient.

Further, the thermoplastic polyester elastomer is suitable as a material for automobile parts, particularly joint boots, but it is not possible to obtain a joint boot having a stable and durable life with conventional thermoplastic polyester elastomers, and the flexibility is high. There is also a drawback that the workability is remarkably poor due to the lack of.

[0006]

As described above, since the thermoplastic polyester elastomer is excellent in mechanical properties, heat resistance, oil resistance, etc., its application is desired to be expanded, but flexibility and compression permanent property are desired. It has the drawback of being inferior in distortion. Therefore, an object of the present invention is to provide a thermoplastic elastomer composition having improved flexibility and compression set without impairing the excellent mechanical properties, heat resistance and oil resistance of the polyester elastomer.

[0007]

The present invention comprises (A) 1 to 98% by weight of a thermoplastic polyester elastomer containing an aromatic liquid crystal polyester as a hard segment, and (B) 99 to 2% by weight of a rubber component. A characteristic thermoplastic elastomer composition is provided.
Further, the present invention provides a thermoplastic elastomer composition obtained by dynamically cross-linking the rubber component (B) during kneading of the thermoplastic elastomer composition.

The thermoplastic polyester elastomer which is the component (A) of the present invention is a polyester block copolymer having a high melting point crystalline segment (A-1) containing an aromatic liquid crystal polyester unit in its polymer chain. And a low melting point polymer segment (A-2) mainly composed of a unit composed of an aliphatic polyether and a dicarboxylic acid and / or an aliphatic polyester unit.

The aromatic liquid crystal polyester unit of the high melting point crystalline segment (A-1) which is a hard segment has at least one so-called thermotropic liquid crystal polyester block which exhibits liquid crystallinity in a molten state. Although the type of liquid crystal polyester is not limited, it is an aromatic polyester having a liquid crystal forming group (mesogen group), and (a)
Short chain aromatic liquid crystal polyester composed of aromatic dicarboxylic acid or ester thereof and divalent phenol, (b) Short chain aromatic liquid crystal polyester composed of aromatic hydroxycarboxylic acid, (c) Aromatic dicarboxylic acid or ester thereof and fat A short-chain aromatic liquid crystal polyester composed of a group diol, (d) a short-chain aromatic liquid crystal polyester composed of a divalent phenol and an aliphatic dicarboxylic acid or an ester thereof,
(E) A typical example thereof is a short-chain aromatic liquid crystal polyester composed of an aromatic dicarboxylic acid or its ester and a divalent phenol and an aliphatic dicarboxylic acid and / or an aliphatic diol.

The above aromatic dicarboxylic acid has the following formula (I):

[Chemical 1] It is represented by. Examples of the substituent of the phenylene group in the above formula (I) include an alkyl group such as chlorine, bromine and methyl group, and the substituted phenylene group can be substituted with 1 to 4 substituents. Specific examples of the aromatic dicarboxylic acid include:
Terephthalic acid, isophthalic acid, diphenyl-m, m'-
Dicarboxylic acid, diphenyl-p, p'-dicarboxylic acid,
Diphenylmethane-m, m'-dicarboxylic acid, diphenylmethane-p, p'-dicarboxylic acid, benzophenone-
4,4'-dicarboxylic acid, naphthalenedicarboxylic acid and the like can be mentioned, and these can be used alone or in combination of two or more kinds. An aliphatic dicarboxylic acid such as adipic acid or sebacic acid may be mixed as long as the liquid crystallinity is not substantially impaired.

The above divalent phenol has the following formula (I
I):

[Chemical 2] It is represented by. Specific examples of the dihydric phenol include:
Hydroquinone, resorcin, dihydroxynaphthalene,
Biphenol (biphenyldiol), 1,8-dihydroxyanthraquinone, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl ether, 4,4'-diphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4 '-Dihydroxy-p-ta-phenyl, 4,4'-di (2-hydroxyethoxy) -p-ta-phenyl, 4,4'-dihydroxy-p-quaterphenyl, 4,4'-di (2 -Hydroxyethoxy) -p-quaterphenyl and the like can be used, and these can be used alone or in combination of two or more kinds. If the liquid crystallinity of the polyester is not impaired, an aromatic diol containing a lower alkylene group such as 2,2- (4-hydroxyphenyl) propane or 4,4'-dihydroxyphenylmethane may be mixed and used. It doesn't matter. These diols may be acetoxy compounds or alkoxy compounds as long as they can finally react to form polyester.

The above aromatic hydroxycarboxylic acid has the following formula (III):

[Chemical 3] It is represented by. Specific examples of the aromatic hydroxycarboxylic acid include m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid and the like, which may be used alone or in combination of two or more. You can These hydroxycarboxylic acids may be ester compounds, acetoxy compounds, and alkoxy compounds as long as they can be finally reacted to form a polyester.

Examples of the above aliphatic diols include glycols having 2 to 12 carbon atoms, such as ethylene glycol,
Propylene glycol, tetramethylene glycol, neopentyl glycol, hexanediol, decanediol, 1,1-cyclohexanedimethanol and the like can be mentioned. Specific examples of the aliphatic dicarboxylic acid include adipic acid, sebacic acid, oxalic acid, succinic acid and the like.

The high melting point crystalline segment (A-1)
The lower limit of the melting point of is not particularly limited, but is generally 150.
℃ or more, preferably 170 ℃ or more, more preferably 190 ℃ or more.

The aliphatic polyether unit constituting the low melting point polymer segment (A-2) which is a soft segment is formed of polyalkylene glycol and dicarboxylic acid. Specific examples of the polyalkylene glycol include:
Polyethylene glycol, polypropylene glycol,
Examples thereof include polytetramethylene glycol and polyethylene glycol-polypropylene glycol block copolymers, with polytetramethylene glycol being particularly preferred. These polyalkylene glycols can be used alone as a mixture as long as the ratio of the number of carbon atoms to the number of oxygen is 2 to 4.5. Further, as the dicarboxylic acid, the above-mentioned aliphatic dicarboxylic acid or aromatic dicarboxylic acid is used. Particularly preferred dicarboxylic acids include adipic acid, sebacic acid, terephthalic acid and isophthalic acid.

The aliphatic polyester unit which is another unit constituting the low melting point polymer segment (A-2) is
Mainly consists of aliphatic dicarboxylic acid and glycol,
The aliphatic dicarboxylic acid which is the main acid component thereof is, for example, succinic acid, adipic acid, sebacic acid, decanedicarboxylic acid and the like. In addition to these aliphatic dicarboxylic acids, a small amount of aromatic dicarboxylic acids such as isophthalic acid may be used together.

The glycol forming the aliphatic polyester unit is a glycol component having 2 to 12 carbon atoms, and specific examples thereof include ethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, hexanediol and decane. Examples include diols.

The aliphatic polyester unit is obtained by polycondensing the above aliphatic dicarboxylic acid and a glycol component by a usual method, and may be a homopolyester or a copolyester, or a ring-opening polymerization of a cyclic lactone. It may be a polylactone (for example, poly ε-caprolactone, poly δ-valerolactone, γ-butyrolactone) obtained in this way.

As the soft segment, an elastomer such as polyorganosiloxane having a hydroxyl group or a carboxylic acid group or its ester group, an amino group or an alkylamino group at both ends may be used in combination.

The low melting point polymer segment (A-2)
The upper limit of the melting point of is not particularly limited, but is generally 130.
C. or lower, preferably 100.degree. C. or lower. Also,
The molecular weight of the low melting point polymer segment (A-2) is usually 4
It is from 00 to 6000.

Thermoplastic polyester elastomer (A)
The composition ratio of the high melting point crystalline segment (A-1) and the low melting point polymer segment (A-2) in the medium is preferably 95/5 to 5/95 by weight, and more preferably 70 /
30 to 30/70. As the thermoplastic polyester elastomer (A), one having a softening point of 100 ° C. or higher is particularly preferable.

Thermoplastic polyester elastomer (A)
The polyester block copolymer particularly preferably used as the high melting point crystalline segment (A-1) is p
-Hydroxybenzoic acid, copolymer of 2,6-naphthalenedicarboxylic acid and hydroquinone, copolymer of p-hydroxybenzoic acid and 2,6-naphthalenedicarboxylic acid, copolymer of isophthalic acid and hydroquinone, p -Hydroxybenzoic acid and 2-hydroxy-6-naphthoic acid copolymer, p-hydroxybenzoic acid, 2,6-naphthalenedicarboxylic acid and 2,6-naphthalenediol copolymer, p-hydroxybenzoic acid, Using a copolymer of terephthalic acid and ethylene glycol, a copolymer of biphenol and terephthalic acid, a copolymer of dihydroxy-p-quaterphenyl and adipic acid, and the like, polytetramethylene as a low-melting polymer segment (A-2). Polyether such as glycol and dicarboxylic acid such as adipic acid La adipate, poly -ε-
It is formed using polyester such as caprolactone.

Further, a polycarboxylic acid, a polyfunctional hydroxy compound, an oxy acid or the like may be copolymerized as a part of the dicarboxylic acid or glycol. By copolymerizing these polyfunctional components in the range of 3 mol% or less, they effectively act as a viscosity increasing component. Examples of the polyfunctional component include trimellitic acid, trimesic acid,
Examples thereof include pyromellitic acid, benzophenonetetracarboxylic acid, butanetetracarboxylic acid, glycerin, pentaerythritol, esters thereof, and acid anhydrides.

Thermoplastic polyester elastomer (A)
Can be produced by a usual polymerization method. As a suitable polymerization method, an aromatic dicarboxylic acid or its dimethyl ester and a low melting point segment-forming diol are heated to about 150 to 260 ° C. in the presence of a catalyst to carry out an esterification reaction or a transesterification reaction, and then, A method for obtaining a thermoplastic elastomer by carrying out a polycondensation reaction while removing excess low-molecular diol under vacuum, a high-melting point polyester segment-forming prepolymer and a low-melting point polymer segment-forming prepolymer which have been prepared in advance, A method for obtaining a thermoplastic polyester elastomer by mixing a bifunctional chain extender that reacts with the terminal group of the prepolymer of (1) and reacting, and then removing the volatile components by keeping the system in a high vacuum. The high-melting point polyester and the lactone are heated and mixed, and the lactone is subjected to ring-opening polymerization while being mixed. And a method of obtaining a thermoplastic polyester elastomer by Le exchange reaction.

As the rubber component which is the component (B) of the present invention, various synthetic rubbers or natural rubbers can be used alone or in combination of two or more kinds. Specific examples of the rubber component (B) that can be used include natural rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber, styrene-isoprene copolymer rubber, and other nonpolar diene rubbers and hydrogenation thereof. Acrylonitrile-butadiene copolymer rubber, (meth) acrylic acid ester-butadiene copolymer rubber,
Polar diene rubbers such as (meth) acrylic acid ester-acrylonitrile-butadiene copolymer rubber and hydrogenated products thereof, (meth) acrylic acid ester rubber, (meth) acrylic acid ester- (meth) acrylic acid copolymer rubber, Mainly (meth) acrylic acid ester such as (meth) acrylic acid-acrylonitrile copolymer rubber, (meth) acrylic acid ester-ethylene copolymer rubber, (meth) acrylic acid ester-ethylene- (meth) acrylic acid copolymer rubber So-called acrylic rubber as a component, so-called hydrin rubber typified by epichlorohydrin alone or copolymer rubber with ethylene oxide, chloroprene rubber, chlorinated polyethylene rubber, chlorosulfonated polyethylene rubber, chlorinated butyl rubber,
Halogenated rubbers such as brominated butyl rubber and chlorinated ethylene-propylene rubber, so-called ethylene-propylene rubbers such as ethylene-propylene copolymer rubbers and crosslinkable third component copolymer rubbers such as ethylene-propylene and ethylidene norbornene. , And so on. Furthermore, in addition to the above, so-called polysulfide rubber, chlorophosphazene rubber,
General synthetic rubbers such as urethane rubber, ethylene-vinyl acetate copolymer rubber, polyethylene oxide rubber, silicone rubber, and fluorine rubber, styrene-butadiene block copolymer, styrene-isoprene block copolymer, or hydrogenated products of these , A thermoplastic polyurethane elastomer, a thermoplastic chloroolefin elastomer, a thermoplastic polyamide elastomer, a composition based on polypropylene / ethylene-propylene copolymer rubber or a dynamically crosslinked composition thereof,
A composition containing a polypropylene / acrylonitrile-butadiene copolymer rubber as a main component or a dynamically crosslinked composition thereof,
Polypropylene / styrene-butadiene block copolymer-based composition or dynamic cross-linking composition thereof, polypropylene / styrene-isoprene block copolymer-based composition or dynamic cross-linking composition thereof, polypropylene / Styrene-butadiene block copolymer hydrogenated composition as a main component or dynamic crosslinking composition thereof, polypropylene / styrene-isoprene block copolymer hydrogenated composition as a main component or dynamic crosslinking composition thereof Examples include so-called thermoplastic elastomers such as objects. Further, other thermoplastic polyester elastomers that do not exhibit liquid crystallinity may be used together with the rubber component as described above.

As the rubber component (B), various kinds of synthetic rubbers and natural rubbers as described above can be used, but when the thermoplastic elastomer composition of the present invention is used as a constant velocity joint boot material, grease is always used. The rubber component (B) having high oil resistance is more preferable because it is used in contact with the rubber component (B). Rubber component with high oil resistance (B)
Specifically, the rubber having a solubility parameter value of 8.0 or more is preferable, more preferably 8.5 or more, and most preferably 9.0 or more.
Regarding the solubility parameter value of the rubber component (B), the values already described in documents such as the Rubber Industry Handbook issued by the Japan Rubber Association and the introduction of new rubber technology issued by the association can be used as a reference, but regarding rubber components not known in the literature Can be determined by various methods described in the solvent handbook published by Kodansha. In the present specification, the solubility parameter value of a rubber component which is not known in the literature is based on the value obtained by “a simple method of trial calculation from the molecular cohesive energy constant of a substance” proposed by Small.

As the rubber component (B) having high oil resistance, the above-mentioned polar diene rubber and hydrogenated products thereof, acrylic rubber, hydrin rubber, urethane rubber, chlorophosphazene rubber, thermoplastic polyurethane elastomer, thermoplastic polyamide elastomer are used. And the like can be preferably used. Furthermore, although silicone rubber and fluororubber have low solubility parameters, they have high oil resistance and therefore can be preferably used.

The blending ratio of the thermoplastic polyester elastomer (A) in the composition of the present invention is 1 to 98% by weight,
Preferably 51-95% by weight, more preferably 55-
85% by weight, and the compounding ratio of the rubber component (B) is 99-
It is 2% by weight, preferably 49 to 5% by weight, more preferably 45 to 15% by weight. The blending ratio of component (A) is 9
If it exceeds 8% by weight, the effect of improving the flexibility and compression set of the obtained composition is not sufficiently observed. Further, if the blending ratio of the component (A) is less than 1% by weight, the processability and fluidity of the obtained composition will be poor.

The rubber component (B) of the present invention is preferably dispersed and mixed in the thermoplastic polyester elastomer (A), and the average particle size at that time is preferably 50 μm.
m or less, more preferably 10 μm or less, particularly preferably 5 to 0.01 μm or less. If the dispersed average particle size of the rubber component (B) is larger than 50 μm, good physical properties cannot be obtained. In the present invention, 100 or more rubber particles are measured in a random visual field observed with an electron microscope, and the average value of the diameters is defined as the average particle diameter. Also, for non-spherical particles, the diameter is taken as the circular area.

In the present invention, in addition to simply blending the thermoplastic polyester elastomer (A) and the rubber component (B), the rubber component (B) is dynamically blended during kneading in order to obtain higher performance. It can be crosslinked. In the composition of the present invention that has been dynamically crosslinked, the rubber component (B)
The gel content is usually 50% by weight or more, preferably 70% by weight.
It is more than weight%. The gel content is the rubber component (B) after crosslinking with a solvent (for example, toluene or methyl ethyl ketone) that can sufficiently dissolve the rubber component (B) before crosslinking.
Is dissolved, and the ratio of insoluble matter at that time is calculated.

The dynamic cross-linking carried out in the present invention is the Unir
Oyal's W.I. M. Fischer et al., Monsa
N.A. Y. It is a method developed by Coran et al., Which is a process of blending rubber in a matrix of a thermoplastic resin, highly kneading the rubber component while kneading with a crosslinking agent, and finely dispersing the rubber component. is there.

As the cross-linking agent used in the dynamic cross-linking of the present invention, peroxides, resin cross-linking agents, sulfur and the like used for ordinary rubber can be used. Specific examples of the cross-linking agent include, for example, cross-linking agents and cross-linking assistants described in "Crosslinking Agent Handbook (Fuzo Yamashita, Tosuke Kaneko, Taiseisha)".
Examples include crosslinking accelerators.

That is, in the present invention, a sulfur or aliphatic crosslinking agent can be preferably used.

In particular, when a sulfur or aliphatic cross-linking agent is used as the cross-linking agent, the main cross-linking agent is preferably 0.1 to 100 parts by weight based on 100 parts by weight of the rubber component (B) in the composition of the present invention. 8 parts by weight, vulcanization accelerator 0.1 to 10 parts by weight,
Vulcanization acceleration aid 0.5 to 10 parts by weight, activator 0.5 to 10
Parts by weight and 0.1 to 10 parts by weight of a crosslinking aid are added.

When an organic peroxide is used as a crosslinking agent, the amount of active oxygen in the organic peroxide is 0.000 relative to 100 parts by weight of the rubber component (B) in the composition of the present invention.
The amount of the organic peroxide to be 1 to 0.3 mol is calculated and added. If the amount of active oxygen is less than 10,0001 mol, sufficient crosslinking will not occur. On the other hand, even if it is used in excess of 0.3 mol, further crosslinking cannot be expected, it is not economical, and other undesirable side reactions such as decomposition of the polymer are likely to occur.

Dynamic crosslinking in the present invention is carried out by various extruders,
It is carried out by kneading the above components with a Banbury mixer, a kneader, or a combination thereof. However, when productivity is taken into consideration, it is most preferable to continuously produce using a twin-screw extruder.
In this case, the plasticizer and the crosslinking agent are added from the middle of the extruder.

The twin-screw extruder used at this time is L /
A long axis type having D = 30 or more is preferable. The method of adding each component at the time of melt-kneading includes the method of simultaneously adding both the components (A) and (B) of the present invention and the crosslinking agent,
Although any of the methods of kneading both components (B) and then adding the crosslinking agent halfway may be used, the method of kneading both components (A) and (B) of the present invention and then adding the crosslinking agent is preferable.
The degree of dynamic crosslinking in the present invention includes the gel content in the component (B), the average dispersed particle size of the component (B), the distribution of the lateral relaxation time measured by the pulse NMR method described later, the uncrosslinked composition and the dynamics. It can be confirmed by comparing the lateral relaxation time (T ₂ l) in the long-term region of the chemically crosslinked composition.

In the present invention, the transverse relaxation time (hereinafter referred to as "the transverse relaxation time" measured at room temperature by the pulse NMR method of the composition obtained by dynamically crosslinking the components (A) and (B) of the present invention during kneading. , T ₂ ) is preferably as follows. That is, T ₂ is 100 to 500 μs
Long-term region (hereinafter referred to as T ₂ l), 20 μs to 10 μs
Medium time region of less than 0 μs (hereinafter referred to as T ₂ m) and short time region of 0 to less than ₂₀ μs (hereinafter referred to as T ₂ s)
When divided into three areas, T ₂ l
Of 55 to 85%, T ₂ m of 5 to 20% and T ₂ s of 1
Try to be 0-40%.

If the T ₂ l is less than 55%, the T ₂ m is more than 20%, or the T ₂ s is more than 40%, the flexibility and compression set of the resulting composition are poor. Further, when T ₂ m is less than 5% or T ₂ s is less than 10%, the mechanical strength of the obtained composition is poor.

There are various methods for measuring T ₂ by the pulse method NMR, but the solid echo method is preferable because it can accurately measure T ₂ for a heterogeneous solid.

The ratio of T ₂ l, T ₂ m and T ₂ s is calculated by approximating the measured signal (FID) to the following equation 1 to obtain the signal strength at T ₂ l, T ₂ m and T ₂ s, and the ratio thereof. Can be obtained from

[0042]

[Equation 1]

Regarding these measuring methods and analyzing methods,
For example, "Magnetic Resonance of Polymers", Polymer Experiments 18, edited by Editorial Committee of Polymer Experiments, Polymer Society of Japan, Kyoritsu Publishing Co., Ltd. (1
975) and the like.

The T ₂ thus obtained is the thermoplastic polyester elastomer (A) used as a raw material.
Also differ depending on the kind of and the rubber component (B), using the same raw material with respect to T ₂ l ratio of the composition of the uncrosslinked prepared in the same composition, T ₂ l of the composition subjected to dynamic crosslinking A composition of 99% or less, preferably 98 to 87%, and more preferably 97 to 90%, a more improved composition can be obtained. Above 99%, the mechanical properties and compression set can be improved. The distortion is inferior.

In the present invention, a so-called compatibilizer is used in order to sufficiently disperse the rubber component (B) in the thermoplastic polyester elastomer (A) and to strengthen its interface to further improve the physical properties. You can Compatibilizers are roughly classified into those that do not involve chemical reaction and those that do not. The former is usually a block copolymer or a graft copolymer and exhibits a so-called emulsifying action. The latter is a polymer having a functional group at the terminal or side chain, or a polymer macromer having a polymerizable group at the terminal of the polymer.

Specific examples of the compatibilizer that can be used in the present invention include ethylene / glycidyl methacrylate copolymer-polymethyl methacrylate graft polymer, ethylene / glycidyl methacrylate copolymer-
Acrylonitrile / styrene copolymer graft polymer, ethylene / glycidyl methacrylate copolymer-polystyrene graft polymer, ethylene / ethyl acrylate copolymer-polymethyl methacrylate graft polymer, ethylene / ethyl acrylate copolymer-polyacrylonitrile graft polymer, ethylene / Ethyl acrylate copolymer-polyacrylonitrile graft polymer, ethylene / ethyl acrylate copolymer-polystyrene graft polymer, ethylene / vinyl acetate copolymer-polymethyl methacrylate graft polymer,
Ethylene / vinyl acetate copolymer-polyacrylonitrile graft polymer, ethylene / vinyl acetate copolymer-polystyrene graft polymer, polypropylene-polyacrylonitrile graft polymer, polypropylene-polystyrene graft polymer, polypropylene-polystyrene graft polymer, polyethylene-polymethylmethacrylate graft Polymer, polyethylene-polyacrylonitrile graft polymer, polyethylene-polystyrene graft polymer, epoxy modified polystyrene-polymethylmethacrylate graft polymer, polybutylene terephthalate-polystyrene graft polymer, acid modified acrylic-polymethylmethacrylate graft polymer, acid modified acrylic-polystyrene graft polymer , Police - polymethyl methacrylate graft polymer, polystyrene - polyethylene graft polymer, polystyrene - polybutadiene graft polymer, polystyrene - polyacrylonitrile block copolymer, polystyrene - polybutyl acrylate block copolymer.

Further, as specific examples of the compatibilizer, MODEPER A1100, A3100, A4 manufactured by NOF CORPORATION
100, A5100, A6100, A1200, A42
00, A5200, A6200, A1400, A340
0, A4400, A5400, A6400, RESEDA (registered trademark) GP1 manufactured by Toagosei Chemical Industry Co., Ltd.
00, GP200, GP300, GP400, GP50
Commercial products such as 0 and GP700 can also be mentioned. An example of a compatibilizing agent including these is “Surface” by Saburo Akiyama 19
1991 Vol. 29, No. 1 and Kaji Maeda et al., “Polymer Processing”, 1991, 40, No. 4, etc.

Among these compatibilizers, those particularly preferable are those having an epoxy group or a carboxyl group which directly reacts with the thermoplastic polyester elastomer (A), depending on the kind of the rubber component (B) used. is there.

The flexural modulus of the composition of the present invention at room temperature is usually 700 kgf / cm ² or less, preferably 700 to 100, when measured according to ASTM D790.
kgf / cm ² , particularly preferably 600 to 100 kgf
/ Cm ² . This bending modulus is 700kgf /
When it exceeds cm ² , the flexibility of the obtained composition is poor.

A plasticizer may be added to the composition of the present invention in order to further improve flexibility and fluidity within a range that does not impair mechanical strength and the like. Plasticizers that can be used include mineral oil-based rubber softeners called process oils or extending oils, dioctyl phthalate, dibutyl phthalate, diethyl phthalate, butylbenzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, diun. Phthalates such as decyl phthalate and diisononyl phthalate, tricresyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trimethyl phosphate, tributoxyethyl phosphate, tris-chloroethyl phosphate, tris-dichloropropyl phosphate,
Condensed phosphate, triphenyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, trilauryl phosphate, tricetyl phosphate, tristearyl phosphate, trioleyl phosphate, and other phosphates Esters, trimellitic acid octyl ester, trimellitic acid isononyl ester, trimellitic acid isodecyl ester and other trimellitic acid esters, dipentaerythritol esters, dioctyl adipate, dimethyl adipate, di-2-ethylhexyl adipate, diisobutyl Adipate, dibutyl adipate, diisodecyl adipate, dibutyl diglycol adipate, di-2-ethylhexe Fatty acid esters such as luazelate, dioctyl azelate, dioctyl sebacate, di-2-ethylhexyl sebacate, and methylacetyl ricinoleate, pyromellitic acid esters such as octyl pyromellitic acid ester, epoxidized soybean oil, epoxidized linseed oil , Epoxy-based plasticizers such as epoxidized fatty acid alkyl ester (eg, epoxidized fatty acid octyl ester), and polyether-based plasticizers such as adipic acid ether ester, polyether ester, and polyether. These plasticizers are independent. Or in combination of two or more.

When the above-mentioned plasticizer is added to the composition of the present invention, phthalic acid esters, phosphoric acid esters, epoxy plasticizers, polyether plasticizers and the like are preferable from the viewpoint of bleeding property, and more preferably Phthalates and polyether plasticizers. The addition of plasticizer is
It may be added before or after the addition of the cross-linking agent, or a part thereof may be added before the cross-linking and the rest may be added after the cross-linking.

The composition of the present invention contains liquid acrylonitrile-
By blending a liquid rubber such as a butadiene copolymer rubber, a liquid acrylic rubber or a liquid polybutadiene rubber in a range that does not impair the mechanical strength, the fluidity and flexibility can be further improved.

The composition of the present invention contains a filler such as calcium carbonate, to the extent that flowability and mechanical strength are not impaired.
Calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, alumina, barium sulfate, aluminum sulfate, calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite,
Carbon black, carbon fiber or the like, or colorants such as carbon black, ultramarine blue, titanium oxide, zinc white, red iron oxide, dark blue, azo pigment, nitrone pigment, lake pigment, phthalocyanine pigment, or modifier such as silicone oil. Can be blended.

Further, several kinds of various stabilizers such as an antiaging agent, a light stabilizer and an ultraviolet absorber may be added in combination. Specific examples of the antiaging agent include phenyl-
α-naphthylamine (PAN), octyldiphenylamine, N, N′-diphenyl-p-phenylenediamine (DPPD), N, N′-di-β-naphthyl-p-phenylenediamine (DNPD), N- ( 1,3-Dimethyl-butyl) -N'-phenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine (IPPD), N, N'-diallyl-p-phenylenediamine, phenothiazine derivative , Diallyl-
p-Phenylenediamine mixture, alkylated phenylenediamine, 4,4'-α, α-dimethylbenzyl) diphenylamine, p, p-toluenesulfonylaminodiphenylamine, N-phenyl-N '-(3-methacryloyloxy-2- Hydropropyl) -p-phenylenediamine, diallylphenylenediamine mixture, diallyl-p-phenylenediamine mixture, N- (1-methylheptyl) -N'-phenyl-p-phenylenediamine,
Amine-based antiaging agents such as diphenylamine derivatives, 2
-Mercaptobenzimidazole (MBI), zinc salt of 2-mercaptobenzothiazole (ZnMBI), 2-
Zinc salt of mercaptomethylbenzimidazole, tributylthiourea, 2-mercaptomethylbenzimidazole, 1,3-bis (dimethylaminopropyl) -2-
Imidazole anti-aging agents such as thiourea, 2,5-
Di-t-amyl hydroquinone (DAHQ), 2,5-
Di-t-butylhydroquinone (DBHQ), 4,4'-
Hydroxydiphenylcyclohexane, 2,2'-methylenebis (4-methyl-6-t-butylphenol)
(MBMTB), 2,6-di-t-butyl-4-methylphenol, 4,4'-thio-bis (6-t-butyl-)
3-methylphenol), styrene phenol,
2,2'-methylene-bis- (4-ethyl-6-t-butylphenol), 2,6-di-t-butyl-4-ethylphenol, bis (3,5-di-t-butyl-4-) (Hydroxybenzyl) sulfide, phenol derivatives such as phenol derivatives and bisphenol derivatives, reaction products of acetone and diphenylamine (ADPA
L), a reaction product of diphenylamine, aniline and acetone, a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline (TMDQ), 6-ethoxy-2,2,4.
-Trimethyl-1,2-dihydroquinoline (ETMD
Q), reaction products of amines and ketones, di-lauryl-thiopropionate, nickel dibutyl-dithiocarbamate (NiDBC), nickel diethyl-dithiocarbamate, nickel dimethyl-dithiocarbamate, nickel dimethyl-dithiocarbamate, etc. Antioxidants such as acid salt-based antiaging agents, antiaging agents such as tri (nonylphenyl) phosphate, tri (nonylphenyl) phosphite, triphenylphosphite, diphenylisodecylphosphite, trioctadecylphosphite, tridecylphosphite, thio Secondary antiaging agents such as dipropionic acid, dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate and distearyl β, β-thiodibutyrate can be mentioned.

Specific examples of the light stabilizer and the ultraviolet absorber include 4-t-butylphenyl salicylate, 2,4-dihydroxybenzophenone and 2,2'-dihydroxy-.
4-methoxybenzophenone, ethyl-2-cyano-
3,3'-diphenyl acrylate, 2-ethylhexyl-2-diano-3,3'-diphenyl acrylate,
2 (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2
(2'-hydroxy-3,5'-di-t-butylphenyl) benzotriazole, 2 (2'-hydroxy-5 '
-Methylphenyl) benzotriazole, 2-hydroxy-5-chlorobenzophenone, 2-hydroxy-4-
Methoxybenzophenone-2-hydroxy-4-octoxybenzophenone, 2 (2'-hydroxy-4-octoxyphenyl) benzotriazole, monoglycol salicylate, oxalic acid amide, phenylsalicylate, 2,2 ', 4 , 4'-tetrahydroxybenzophenone and the like.

The thermoplastic elastomer composition of the present invention includes polypropylene, polyvinyl chloride, polycarbonate, PET, PBT, polyacetal, polyamide, epoxy resin, vinylidene fluoride, polysulfone,
Ethylene-vinyl acetate copolymer, PPS resin, polyether ether ketone, PPO resin, styrene-methyl methacrylate copolymer, styrene-maleic anhydride copolymer, rubber-modified PPO resin, styrene-maleimide copolymer, A resin such as a rubber-modified styrene-maleimide copolymer can be appropriately blended.

The hardness of the thermoplastic elastomer composition of the present invention is preferably 60 to 95 points (JIS A hardness), more preferably 70 to 95 points, and particularly preferably 80 to 95 points. If the hardness is unnecessarily low, for example, when the thermoplastic elastomer composition of the present invention is used as a joint boot, the bellows portion of the boot is deficient in rotational expansion resistance due to rotational centrifugal force during high-speed rotation, In addition, the negative pressure resistance characteristic, in which the long part of the bellows film is caught due to the decrease in the internal pressure of the boot due to the decrease in temperature, is also insufficient. If the hardness is too high, the object of the present invention cannot be achieved.

The thermoplastic elastomer composition of the present invention comprises
It can be processed by a processing method such as blow molding or injection blow molding. However, the composition of the present invention can be injection-molded. For example, in the case of producing a constant velocity joint boot, the boot having a uniform thickness can be obtained by injection molding. In order to manufacture joint boots by injection molding, the composition MFR
(The fluidity measured at 230 ° C. under a load of 10 kg) is 0.
1 g / 10 minutes or more, preferably 5-100 g / 10 minutes,
Particularly preferably, it is 10 to 100 g / 10 minutes.

The constant velocity joint boot produced using the thermoplastic polyester elastomer composition of the present invention has basic characteristics such as strength, compression set, heat resistance, weather resistance, cold resistance, and grease resistance, and fatigue resistance, Not only has excellent practical performance such as abrasion resistance, but it is also extremely flexible. That is, the composition of the present invention is a material for new joint boots (particularly constant velocity joint boots) in which the drawbacks of the conventional materials such as chloroprene rubber and mere thermoplastic polyester elastomer are improved.

Further, the composition of the present invention is used for a bumper part, a side shield, a steering wheel, a molding,
Steering wheel, rack and pinion type steering wheel boot,
MacPherson strut boots, propeller shaft boots, toe link boots, steering boots, ball joint seals, tie rod seals, universal joint seals, air suspension bellows,
Automotive parts such as rolling diaphragms, footwear such as shoe soles and sandals, electric parts such as electric wire coatings, connectors and cap plugs, golf club grips, baseball bat grips, swimming fins, sports such as underwater glasses,
Leisure goods, rubber contacts for keyboard switches, curl cords, couplings, O-rings, gaskets, waterproof cloth, hydraulic hoses, power steering hoses, vacuum tubes, coil tubes, tubes such as garden hoses, hoses, packing rolls, belts, etc. It can also be used as a material.

[0061]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

Polymerization Example 1 of Liquid Crystal Polyester Elastomer
~ 4: Polymerization Example 1; polyethylene glycol 25 having a molecular weight of 900
Kg, naphthalene dicarboxylic acid 7.7 Kg, hydroquinone diacetate 1.6 Kg and p-hydroxybenzoic acid 3.1 Kg were charged into a reactor equipped with a stirrer, and reacted for 3 hours from 200 ° C. to 300 ° C. under a nitrogen atmosphere.
The pressure was reduced to 15 mmHg over 30 minutes at 0 ° C. 300
After heating at 15 ° C. and 15 mmHg for 30 minutes, it is further heated to 0.
The product was taken out by reducing the pressure to 5 mmHg and heating for 1 hour to obtain a highly viscous polymer. The obtained polymer is called polyester elastomer P-1.

Polymerization Example 2; 30 kg of polytetramethylene glycol having a molecular weight of 1500, 6.6 kg of terephthalic acid,
6.3 Kg of 4,4'-diacetoxy isopropylidene diphenyl, 4.8 Kg of 4-acetoxybenzoic acid and 13 g of sodium acetate were placed in a reactor equipped with a stirrer and kept at 240 ° C for 20 minutes under a nitrogen atmosphere, and then at 260 ° C.
When the temperature was raised to 0, distillation of acetic acid started. After reacting for 45 minutes as it was, it was reacted at 290 ° C. for 45 minutes and at 320 ° C. for 35 minutes to distill further acetic acid. Then, the system was gradually depressurized and kept at 15 mmHg for 15 minutes.
The temperature was raised to 0 ° C. and the pressure was reduced to 0.5 mmHg or less to carry out a polycondensation reaction for 20 minutes. The obtained polymer is called polyester elastomer P-2.

Polymerization Example 3; dimethyl adipate 15.7K
g, 1.9 Kg of dimethyl terephthalate, 20 Kg of 1,4-butanediol and a small amount of tetramethyl titanate were charged into a reactor equipped with a stirrer, and the temperature was 200 ° C. under a nitrogen atmosphere.
And reacted for 1 hour. With the reaction, methanol began to distill and a low molecular weight polyester was produced. 2.6 Kg of 4,4'-dihydroxy-p-terphenyl in the reactor
After adding, the temperature was raised to 320 ° C. and the reaction was carried out for 1 hour.
Then, the reactor was depressurized to 1 mmHg and kept for 30 minutes, the temperature was lowered to 300 ° C., and the reaction was continued for another hour. With the reaction, 1,4-butanediol was distilled. The obtained polymer is called polyester elastomer P-3.

Polymerization Example 4; 4,4'-dihydroxy-p-
Quarter phenyl 15 kg, ε-caprolactone 35
Kg and 0.5 g of tetrabutyl titanate at 200 ° C
And reacted for 4 hours. The obtained polymer is called polyester elastomer P-4.

Reference example: terephthalic acid 3.3 kg, 4,
4'-diacetoxyisopropylidenediphenyl 6.3
Kg, 4.8 Kg of 4-acetoxybenzoic acid and 13 g of sodium acetate were charged into a reactor equipped with a stirrer, and the mixture was kept under a nitrogen atmosphere at 240 ° C for 20 minutes and then heated to 260 ° C to start distillation of acetic acid. After reacting for 45 minutes as it was, it was reacted at 290 ° C. for 45 minutes and at 320 ° C. for 35 minutes to distill further acetic acid. Then, the system was gradually depressurized and held at 15 mmHg for 15 minutes, then heated to 350 ° C. and depressurized to 0.5 mmHg or less and subjected to a polycondensation reaction for 20 minutes to give only the hard segment portion of Polymerization Example 2. When polymerized and observed with a polarizing microscope, it was confirmed that a molten phase having optical anisotropy was formed at about 300 ° C. and exhibited liquid crystallinity.

Examples 1 to 14 (Examples corresponding to the inventions of claims 1 and 2): Example 1; Polyester elastomer P-1 of Polymerization Example 1
And the amount of bound acrylonitrile is 41% by weight, Mooney viscosity (L _{1 + 4} 100 ° C.) is 56, and SP value is 10.0, acrylonitrile butadiene rubber (hereinafter referred to as NBR).
Was kneaded at a rotation rate of 200 rpm at 210 ° C. using a twin-screw extruder in a ratio shown in Table 1, and 100 parts by weight of this composition were used as a crosslinking agent, Kayahexa AD (manufactured by Kayaku Akzo Co.) and Barnock. PM (manufactured by Ouchi Shinko) is 0.
4 parts by weight and 0.6 parts by weight were added to carry out dynamic crosslinking. At the same time, 1% by weight of Nocrac NBC (manufactured by Ouchi Shinko Co., Ltd.) and 0.2% by weight of Irganox 1010 (manufactured by Ciba-Geigy Co., Ltd.) were added as antioxidants to obtain a composition having the physical properties shown in Table 1.

Examples 2 to 14: Compositions were obtained in the same manner as in Example 1 except that the thermoplastic liquid crystal polyester elastomer and the rubber component were changed to those shown in Table 1 or Table 2. However, in Example 7, 0.8 part by weight of ammonium benzoate and 0.4 part by weight of stearic acid were used instead of Kayahexa AD. Further, in Examples 12 and 13, Modiper 4400 (manufactured by NOF Corporation) was added as a compatibilizer.

The rubber components shown in Tables 1 and 2 are as follows. Hydrogenated NBR of Example 4: Terban 1907 (manufactured by Bayer Japan) EPM of Example 5: ethylene-propylene copolymer rubber (JSR EP EP02P, manufactured by Japan Synthetic Rubber Co., Ltd.) Silicone rubber of Example 6: JSR EH5230U
(Manufactured by Japan Synthetic Rubber Co., Ltd.) ACM of Example 7: Acrylic rubber (Knoxtite P
A302, manufactured by Nippon Mektron Co., Ltd.) Epichlorohydrin of Example 8: epichromer HG (manufactured by Daiso) NBR of Examples 9 to 13: acrylonitrile butadiene rubber similar to Example 1 B-1 of Example 14: epoxy-modified NBR (manufacturing method) Is shown below)

Production of epoxy-modified NBR (B-1): bound acrylonitrile content 41%, Mooney viscosity (ML
_{1 + 4} 100 ℃) 56 acrylonitrile butadiene rubber was crushed and kneaded with a twin-screw extruder at 70 ℃, 2,5-dimethyl-2,5-di-t-butyl from the middle of the twin-screw extruder Peroxyhexane was added in an amount of 0.
An epoxy modified NBR was manufactured by adding 05 parts by weight and 0.2 parts by weight of glycidyl methacrylate.

Examples 15 to 18 (Examples corresponding to the invention of claim 2): The same method as in Example 1 except that the thermoplastic liquid crystal polyester elastomer and the rubber component are changed to those shown in Table 2 and crosslinking is not carried out. To produce a composition. NBR of Examples 15 to 18: Acrylonitrile butadiene rubber similar to that of Example 1

Comparative Example 1 (Comparative Example to the Invention of Claim 1): Example 3 except that the amount of NBR added was 1% by weight.
The compositions shown in Table 3 were produced by a method similar to that described above. This comparative example is an example in which the amount of rubber added is less than the range of the present invention, and the obtained composition is inferior in flexibility and compression set.

Comparative Example 2 (Comparative Example to the Invention of Claim 2): The composition shown in Table 3 was kneaded in a 3-liter kneader at 195 ° C. for 30 seconds, a cross-linking agent was added, and the mixture was kneaded for 30 seconds again. Then, a sample was obtained. The obtained sample was crushed and injection molded. This comparative example is an example in which dynamic crosslinking was not carried out, and the rubber particle size of the obtained composition was as large as 60 μm due to insufficient kneading, and therefore the mechanical properties were inferior. Also, the moldability is poor.

Comparative Example 3 Thermoplastic polyester elastomer having no liquid crystallinity (polyester elastomer manufactured by Enikel Polymerie,
PIBIFLEX) 40 parts and bound acrylonitrile amount 41% by weight, Mooney viscosity (L _{1 + 4} 100 ° C.) 56, S
Using a twin-screw extruder, 2 parts of 60 parts of acrylonitrile-butadiene rubber (hereinafter referred to as NBR) having a P value of 10.0 are used.
The mixture was kneaded at 10 ° C. and a rotation speed of 200 rpm, and 0.4 part by weight of Kayahexa AD (manufactured by Kayaku Akzo Co., Ltd.) as a crosslinking agent was added to 100 parts by weight of the composition in the middle of the twin-screw extruder. After crosslinking, 1% by weight of Nocrac NBC (manufactured by Ouchi Shinko Co., Ltd.) and 0.2% by weight of Irganox 1010 (manufactured by Ciba Geigy) were added as antioxidants to obtain a composition. The MFR of the composition was 15. A comparison of the dynamic viscoelastic spectra of the composition of Comparative Example 3 and the composition of Example 3 is shown in FIG. According to FIG. 1, the composition of Example 3 retains the elastic modulus up to around 200 ° C., whereas the composition of Comparative Example 3 decreases in elastic modulus from around 150 ° C. As is clear from this, by using the thermoplastic polyester elastomer containing the aromatic liquid crystal polyester as in the present invention, the MF of the composition can be improved.
The upper limit of the usable temperature can be increased without decreasing R.

Test Example 1 (Physical property evaluation in pellet and sheet form) The compositions obtained in Examples 1 to 18 and Comparative Examples 1 to 3 were pelletized, and a sheet having a thickness of 2 mm was formed by an injection molding machine at 210 ° C. After molding, each physical property was measured and evaluated by the following methods. The results are shown in Tables 1 to 3. Note (1) MFR: Measured at 230 ° C. under a load of 10 kg. (2) Particle size of component (B): 100 or more rubber particles were measured in a random visual field observed with an electron microscope, and the average value thereof was determined. (3) Hardness: JIS K-6301 JIS A hardness (4) Tensile strength: JIS K-6301 JIS 3
No. Damper (5) Tensile elongation: JIS K-6301 JIS 3
No. Damper (6) Flexural Modulus: Measured according to ASTM D790. (7) Compression set: JIS K-6301 120 ° C
22 hours (8) Heat aging resistance: JIS K-6301 Gear type aging tester was used to measure the tensile strength after aging at 120 ° C. for 300 hours, and the change rate (%) relative to the tensile strength before the heat resistance test. Indicated by. (9) Oil resistance: JIS K-6301 JIS No. 3 oil was immersed in oil at 120 ° C. for 70 hours, and the tensile strength was measured, and the change rate (%) with respect to the tensile strength before the oil resistance test was shown. (10) Molding appearance: Molding workability was evaluated as good when there were no short shots and there were no marked defects in appearance (flow marks, delamination).

[0076]

[Table 1]

[Table 2]

[Table 3]

Test Example 2 (Evaluation of physical properties in joint boot shape) The compositions obtained in Examples 1 to 14 and Comparative Examples 1 to 3 were injection-molded using a boot mold to obtain a joint boot having a thickness of 1 mm. Molded. Further, a joint boot made only of a thermoplastic polyester elastomer (Comparative example 3, a comparative example to the invention of claim 1) and a joint boot made only of chloroprene rubber (comparative example 4, claim 1).
Comparative Example for Invention) was molded and the following evaluations were performed. The results are shown in Table 4. (1) Evaluation of hardness and appearance of molding was performed in the same manner as in Test Example 1. (2) Boot life: After the boot obtained by injection molding was attached to a constant velocity joint and grease was filled, the joint angle was kept at 30 degrees and rotated at 400 rpm in an atmosphere of -5 ° C until the boot broke. I asked for time. In addition,
For those that did not break after 50 hours,
In Table 4, 50 hours was entered.

[0078]

[Table 4]

Test Example 3 (Measurement of Transverse Relaxation Time (T ₂ ) by Pulsed NMR) The pellet transverse relaxation time (T ₂ ) of the composition obtained in Example 3 was measured by CXP-90 type NMR (manufactured by Bruker Japan Ltd.). ¹ H nucleus 90 MHz) was used to measure at 25 ° C. by the solid echo method. The measurement result is T ₂ l = 60%,
T ₂ m = 15%, T ₂ s = 25%, T ₂ l / Example 15
T ₂ l = 92%.

[0080]

The thermoplastic polyester elastomer of the present invention has excellent mechanical properties, oil resistance and heat resistance, and has improved flexibility and compression set. That is, according to the present invention, it is possible to provide a composition excellent in hardness, tensile strength, tensile elongation, compression set, heat aging resistance, oil resistance and molding appearance, and this composition is particularly useful for joints. It can be suitably used as automobile parts such as boots.

[Brief description of drawings]

1 is a graph showing the dynamic viscoelastic spectra of the composition of Example 3 and the composition of Comparative Example 3. FIG.

Claims (2)

[Claims] 1. A thermoplastic polyester elastomer containing 1 to 98% by weight of (A) an aromatic liquid crystal polyester as a hard segment, and (B) 99 to 2% by weight of a rubber component.
A thermoplastic elastomer composition comprising: 2. The thermoplastic elastomer composition according to claim 1, wherein the rubber component (B) is dynamically cross-linked during kneading.