THERMOPLASTIC ELASTOMER COMPOSITION, VIBRATION-DAMPING MATERIAL, GEAR, AND MOLDED COMPOSITE OBJECT

Abstract

Provided is a thermoplastic elastomer composition and the like which can have improved vibration-damping properties while retaining properties inherent in a polyester-based thermoplastic elastomer. The thermoplastic elastomer composition contains a polyester-based thermoplastic elastomer (A) and a hydrogenated aromatic vinyl compound-based elastomer (B) having a glass transition temperature Tg of −10 to 40° C., wherein the hydrogenated aromatic vinyl compound-based elastomer (B) is a hydrogenate of a block copolymer containing a polymer block (a) having a structural unit derived from an aromatic vinyl compound and a polymer block (b) having a structural unit derived from a conjugated diene compound, and the ratio by mass of the polyester-based thermoplastic elastomer (A) to the hydrogenated aromatic vinyl compound-based elastomer (B), (A/B) is 99/1 to 1/99.

Claims

1. A thermoplastic elastomer composition comprising a polyester-based thermoplastic elastomer (A) and a hydrogenated aromatic vinyl compound-based elastomer (B) having a glass transition temperature Tg of −10 to 40° C., wherein: the hydrogenated aromatic vinyl compound-based elastomer (B) is a hydrogenate of a block copolymer containing a polymer block (a) having a structural unit derived from an aromatic vinyl compound and a polymer block (b) having a structural unit derived from a conjugated diene compound, and the ratio by mass of the polyester-based thermoplastic elastomer (A) to the hydrogenated aromatic vinyl compound-based elastomer (B), (A/B) is 99/1 to 1/99.

2. The thermoplastic elastomer composition according to claim 1, wherein a ratio of the storage elastic modulus G′ at 0° C. (G′(0° C.)) to the storage elastic modulus G′ at 50° C. (G′(50° C.)), (G′(0° C.)/G′(50° C.)) of the hydrogenated aromatic vinyl compound-based elastomer (B) is more than 10.

3. The thermoplastic elastomer composition according to claim 1, wherein the ratio by mass of the polyester-based thermoplastic elastomer (A) to the hydrogenated aromatic vinyl compound-based elastomer (B), (A/B) is 75/25 to 95/5.

4. The thermoplastic elastomer composition according to claim 1, wherein the content of the polymer block (a) in the block copolymer is 30% by mass or less.

5. The thermoplastic elastomer composition according to claim 4, wherein the content of the polymer block (a) in the block copolymer is 16% by mass or less.

6. The thermoplastic elastomer composition according to claim 1, wherein the conjugated diene compound contains isoprene.

7. The thermoplastic elastomer composition according to claim 1, wherein the polymer block (b) has a structural unit containing at least one alicyclic skeleton (X) represented by the following formula (X) in the main chain: ##STR00004## wherein R.sup.1 to R.sup.3 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and plural R.sup.1 to R.sup.3 each may be the same or different.

8. The thermoplastic elastomer composition according to claim 7, wherein at least one alicyclic skeleton (X) is an alicyclic skeleton (X′) where at least one of R.sup.1, R.sup.2 or R.sup.3 is a hydrocarbon group having 1 to 11 carbon atoms.

9. The thermoplastic elastomer composition according to claim 1, wherein the hydrogenation rate of the polymer block (b) is 85 to 99 mol %.

10. The thermoplastic elastomer composition according to claim 1, wherein the vinyl bond content in the polymer block (b) is 65 to 90 mol %.

11. The thermoplastic elastomer composition according to claim 1, wherein the weight-average molecular weight of the hydrogenated aromatic vinyl compound-based elastomer (B) is 30,000 to 300,000.

12. The thermoplastic elastomer composition according to claim 1, wherein the peak top intensity of tanδ of the hydrogenated aromatic vinyl compound-based elastomer (B) is 1.0 or more.

13. The thermoplastic elastomer composition according to claim 1, wherein the maximum value of the tanδ intensity at 0 to 40° C. of the thermoplastic elastomer composition is 0.1 or more.

14. The thermoplastic elastomer composition according to claim 13, wherein the maximum value of the tanδ intensity at 0 to 40° C. of the thermoplastic elastomer composition is 0.15 or more.

15. The thermoplastic elastomer composition according to claim 1, wherein the maximum value of the tanδ intensity at 0 to 40° C. of the polyester-based thermoplastic elastomer (A) is 0.05 or more.

16. The thermoplastic elastomer composition according to claim 1, wherein the ratio of the maximum value of the tanδ intensity at 0 to 40° C. of the hydrogenated aromatic vinyl compound-based elastomer (B) to the maximum value of the tanδ intensity at 0 to 40° C. of the polyester-based thermoplastic elastomer (A), (tanδ(B)max/tanδ(A)max) is 10 to 80.

17. A vibration-damping material comprising the thermoplastic elastomer composition of claim 1.

18. A gear comprising the thermoplastic elastomer composition of claim 1.

19. A composite molded object, wherein a thermoplastic elastomer composition layer containing the thermoplastic elastomer composition of claim 1 bonds by fusion to a polar resin layer containing a polar resin.

Description

EXAMPLES

[0211] Hereinunder the present invention is described more concretely with reference to Examples and Comparative Examples, but the present invention is not restricted to these.

<Hydrogenated Aromatic Vinyl Compound-Based Elastomer (B)>

[0212] Physical properties evaluation methods for the hydrogenated aromatic vinyl compound-based elastomer (B) produced in Production Examples given hereinunder are shown below.

(1) Content of Polymer Block (a)

[0213] An unhydrogenated block copolymer was dissolved in CDCl.sub.3, and by .sup.1H-NMR measurement [device: “ADVANCE 400 Nano bay” (by Bruker Corporation), measurement temperature: 30° C.)], the content of the polymer block (a) therein was calculated from the ratio of a peak intensity derived from styrene as an aromatic vinyl compound and a peak intensity derived from a diene.

(2) Weight-Average Molecular Weight (Mw)

[0214] By gel permeation chromatography (GPC) measurement under the conditions mentioned below, the polystyrene-equivalent weight-average molecular weight (Mw) of the hydrogenated aromatic vinyl compound-based elastomer (B) was determined.

<<GPC Measurement Device and Measurement Conditions>>

[0215] Device: GPC device “HLC-8020” (by Tosoh Corporation)
Separation column: “TSKgel GMHXL”, “G4000HXL” and “G5000HXL” all by Tosoh Corporation were connected in series.

Eluent: Tetrahydrofuran

[0216] Eluent flow rate: 0.7 mL/min
Sample concentration: 5 mg/10 mL
Column temperature: 40° C.
Detector: Differential refractive index (RI) detector
Calibration curve: Drawn with standard polystyrene

(3) Hydrogenation Rate of Polymer Block (b)

[0217] By .sup.1H-NMR measurement, the hydrogenation rate was calculated from the ratio of a peak area derived from the residual olefin of isoprene and/or butadiene to a peak area derived from ethylene, propylene and/or butylene.

Device: Nuclear magnetic resonance device “ADVANCE 400 Nano bay” (by Bruker Corp oration)

Solvent: CDCl.SUB.3

(4) Vinyl Bond Content in Polymer Block (b)

[0218] An unhydrogenated block copolymer was dissolved in CDCl.sub.3, and analyzed by .sup.1H-NMR measurement [device: “ADVANCE 400 Nano bay” (by Bruker Corporation), measurement temperature: 30° C.)]. From the ratio of a peak area corresponding to the 3,4-bond unit and the 1,2-bond unit in the isoprene structural unit, or the 1,2-bond unit in the butadiene structural unit, or the bonding units of the two in the case of a structural unit derived from a mixture of isoprene and butadiene, to a total peak area of structural units derived from isoprene and/or butadiene, the vinyl bond content (total content of the 3,4-bond unit and the 1,2-bond unit) was calculated.

(5) Content of Alicyclic Skeleton (X) in Polymer Block (b)

[0219] 600 mg of an unhydrogenated block copolymer and 40 mg of Cr(acac).sub.3 were dissolved in 4 mL of CDCl.sub.3, and using a 10-mm NMR tube, this was subjected to quantitative .sup.13C-NMR measurement (pulse program: zgig, Inverse gated .sup.1H decoupling method) [device: “ADVANCE 400 Nano bay” (by Bruker Corporation), measurement temperature: 30° C.)]. According to the method mentioned below, the content of the alicyclic skeletons X, X1 and X2 in the polymer block (B) was calculated.

[0220] In Table 3, X, X1 and X2 each are the following alicyclic skeleton.

[0221] X: Alicyclic skeleton having a combination of substituents of the following (i) to (vi).

[0222] X1: Alicyclic skeleton having a combination of substituents of the following (i) and (iv).

[0223] X2: Alicyclic skeleton having a combination of substituents of the following (ii), (iii), (v) and (iv).

[0224] (i): R.sup.1=hydrogen atom, R.sup.2=hydrogen atom, R.sup.3=hydrogen atom; (1,2Bd+Bd)

[0225] (ii): R.sup.1=hydrogen atom, R.sup.2=methyl group, R.sup.3=hydrogen atom; (1,2Bd+1,2Ip)

[0226] (iii): R.sup.1=hydrogen atom, R.sup.2=hydrogen atom, R.sup.3=methyl group; (1,2Bd+3,4Ip)

[0227] (iv): R.sup.1=methyl group, R.sup.2=hydrogen atom, R.sup.3=hydrogen atom; (1,2Ip+Bd)

[0228] (v): R.sup.1=methyl group, R.sup.2=methyl group, R.sup.3=hydrogen atom; (1,2Ip+1,2Ip)

[0229] (vi): R.sup.1=methyl group, R.sup.2=hydrogen atom, R.sup.3=methyl group; (1,2Ip+3,41p)

[Calculation Method]

[0230] Table 1-1 shows each peak and the derived structure. When the integrated value of each peak is represented by a to g, the integrated value of each structure can be as shown in Table 1-2. The content of X, X1 and X2 each can be calculated as (a+g−c)/(a+b+c−d+e/2+2f, (g−c)/(a+b+c−d+e/2+2f, and a/(a+b+c−d+e/2+2f, respectively.

TABLE-US-00001 TABLE 1-1 Peak (ppm) Structure Integrated Value 108-110 X2 a 110-113 3,4 Ip + 1,2 Ip + X1 b 113-116 1,2 Bd c 122-127 1,4 Ip + St d 127-132 1,4 Bd × 2 + St × 4 e 132-137 1,4 Ip f 142-145 1,2 Bd + X1 g

TABLE-US-00002 TABLE 1-2 Structure Integrated Value St d − f 1,4 Ip f 3,4 Ip + 1,2 Ip b − (g − c) 1,4 Bd (e − (d − f) × 4)/2 1,2 Bd c X1 g − c X2 a Total a + b + c − d + e/2 + 2f

(6) Glass Transition Temperature Tg (° C.)

[0231] The glass transition temperature (Tg) of the hydrogenated aromatic vinyl compound-based elastomer (B) of Production Examples 1 to 3 was measured according to the following method. [Measurement of glass transition temperature (Tg)]

[0232] This was measured according to JIS K7121:2012. For the measurement, a differential scanning calorimeter (DSC) (DSC250 by TA) was used. Regarding the measurement conditions for the DSC curve, the sample was once heated up to 230° C., then cooled down to −90° C., and thereafter again heated from −90° C. to 230° C. at a rate of 10° C./min. On the DSC curve in the second time heating, an intermediate point glass transition temperature was read, and the intermediate point glass transition temperature is the glass transition temperature (Tg) of the measured sample.

(7) Peak Top Temperature and Peak Top Intensity of Tanδ, and Maximum Width of Temperature Range where Tanδ is 1.0 or More

[0233] For the following measurement, the hydrogenated aromatic vinyl compound-based elastomer (B) was pressurized at a temperature of 230° C. and under a pressure of 10 MPa for 3 minutes to give a single layer sheet having a thickness of 1.0 mm. The single layer sheet was cut into a disc, and this was used as a test sheet.

[0234] For the measurement, according to JIS K 7244-10 (2005), a strain control type dynamic viscoelasticity device “ARES-G2” (by TA Instrument Japan Corporation) having a disc diameter of 8 mm was used as a parallel flat plate type oscillation rheometer.

[0235] The gap between the two flat plates was fully filled up with the above test sheet, and at a strain amount of 0.1%, oscillation at a frequency of 1 Hz was given to the test sheet. By heating this from −70° C. to 100° C. at a constant rate of 3° C./min, a maximum value of the peak intensity (peak top intensity) of tanδ and the temperature (° C.) at which the maximum value was given (peak top temperature (° C.)) were determined. In addition, the maximum value of the tanδ intensity at 0 to 40° C. of the hydrogenated aromatic vinyl compound-based elastomer (B) was determined. Further, the maximum width (° C.) of the temperature range in which tanδ was 1.0 or more was determined. A larger value thereof indicates more excellent vibration-damping performance.

(8) G′ Ratio of Hydrogenated Aromatic Vinyl Compound-Based Elastomer (B) (G′(0° C.)/G′(50° C.))

[0236] G′ ratio (G′(0° C.)/G′(50° C.)) of the hydrogenated aromatic vinyl compound-based elastomer (B) of Production Examples 1 to 3 was measured as follows. The hydrogenated aromatic vinyl compound-based elastomer (B) was pressurized at a temperature of 230° C. and under a pressure of 10 MPa for 3 minutes to give a single layer sheet having a thickness of 1.0 mm, and the single layer sheet was cut into a disc to be a test sheet. According to JIS K 7244-10 (2005), the test sheet was analyzed using a strain control type dynamic viscoelasticity device “ARES-G2” (by TA Instrument Japan Corporation) having a disc diameter of 8 mm as a parallel flat plate type oscillation rheometer.

[Production Example 1]

[0237] Production of hydrogenated aromatic vinyl compound-based elastomer (B) 50 kg of a solvent, cyclohexane and 87 g of a cyclohexane solution of an anionic polymerization initiator, sec-butyllithium having a concentration of 10.5% by mass (substantial amount added of sec-butyllithium: 9.1 g) were fed into a nitrogen-purged and dried pressure-resistant container.

[0238] The pressure-resistant container was heated up to 50° C., then 1.0 kg of styrene (1) was added and polymerized for 1 hour, at a container inner temperature of 50° C., 63 g of a Lewis base, 2,2-di(2-tetrahydrofuryl)propane (DTHFP) was added, a mixture liquid of 8.16 kg of isoprene and 6.48 kg of butadiene was added at an average diene feed speed shown in Table 2, taking 5 hours, and then these were polymerized for 2 hours, and further 1.0 kg of styrene (2) was added and polymerized for 1 hour to give a reaction solution containing a polystyrene-poly(isoprene-butadiene)-polystyrene triblock copolymer.

[0239] A Ziegler-type hydrogenation catalyst formed from nickel octylate and trimethylaluminum was added to the reaction solution under a hydrogen atmosphere, and reacted under the condition of a hydrogen pressure of 1 MPa and 80° C. for 5 hours. The reaction solution was left cooled and left depressurized, and then washed with water to remove the catalyst, and dried in vacuum to obtain a hydrogenate of the polystyrene-poly(isoprene-butadiene)-polystyrene triblock copolymer (hydrogenated aromatic vinyl compound-based elastomer (B)).

[0240] The raw materials and the amount used thereof (kg) are shown in Table 2. The results of physical properties evaluation are shown in Table 3.

[Production Examples 2 to 3]

Production of Hydrogenated Aromatic Vinyl Compound-Based Elastomer (B)

[0241] Block copolymer hydrogenates (hydrogenated aromatic vinyl compound-based elastomers (B)) were produced in the same manner as in Production Example 1 except that the components and the amount to be used thereof, and the reaction conditions were changed as in Table 2. The results of physical properties evaluation are shown in Table 3.

TABLE-US-00003 TABLE 2 Production Example 1 2 3 Hydrogenated Aromatic Vinyl B-1 B-2 B-3 Compound-based Elastomer (B) Amount Cyclohexane 50 50 50 Used (kg) Sec-butyllithium (10.5 mass % 0.087 0.087 0.087 cyclohexane solution) (a) Styrene (1) 1.0 1.0 0.5 Styrene (2) 1.0 1.0 1.5 (b) Isoprene 8.16 14.64 8.16 Butadiene 6.48 0 6.48 Others Tetrahydrofuran 0 0 0.31 DTHFP 0.063 0.032 0

TABLE-US-00004 TABLE 3 Production Example 1 2 3 Hydrogenated aromatic vinyl compound- B-1 B-2 B-3 based elastomer (B) Structural unit of polymer block (a) St St St Components constituting polymer block (b) Ip/Bd Ip Ip/Bd Ratio by mass of components constituting 55/45 100 55/45 polymer block (b) Ratio by mol of components constituting 50/50 100 50/50 polymer block (b) Polymer structure A/B/A A/B/A A/B/A Content (% by mass) of polymer block (a) 12 12 12 Weight-average molecular weight of 150,000 150,000 163,000 hydrogenated aromatic vinyl compound-based elastomer (B) Hydrogenation rate (mol %) of polymer block 97 90 91 (b) Vinyl bond content (mol %) in polymer block 76 83 64 (b) X1 in polymer block (b) or hydrogenate 3 0 0 content (mol %) in X1 X2 in polymer block (b) or hydrogenate 5 1 2 content (mol %) in X2 X in polymer block (b) or hydrogenate content 8 1 2 (mol %) in X Glass transition temperature Tg (° C.) −1 20 −30 Peak top temperature (° C.) of tanδ 10 31 −20 Peak top intensity of tanδ 2.2 2.1 2.2 Maximum value of tanδ intensity at 0° C. to 2.2 2.1 0.37 40° C. Maximum width (° C.) of temperature range 17.9 20.7 14.6 where tanδ ≥ 1 G′ ratio (G′(0° C.)/G′(50° C.)) 770 530 1

Examples 1 to 10 and Comparative Examples 1 and 2, and Reference Example

[0242] The hydrogenated aromatic vinyl compound-based elastomers (B) of Production Examples 1 and 2 have a peak top intensity of tanδ of 1.0 or more, and have a peak top temperature of tanδ in a broad temperature range, and therefore can be said to be favorable for wide-range applications as a vibration-damping material.

[0243] Constituent ingredients (part by mass) for a thermoplastic elastomer composition shown in Table 4 and Table 5 were put into Brabender (“Plastograph EC: 50 cc mixer” by Brabender Corporation), and melt-kneaded therein at a cylinder temperature of 240° C. and at a screw rotation number of 100 rpm for 3 minutes, and then the resultant composition was compression-molded (240° C., 2 minutes) to form sheets (thickness 1 mm). Tanδ intensity of the thus-produced sheets (thickness 1 mm) was measured according to the following method. The test pieces used for measurement of the tanδ intensity were used to measure the dispersion diameter (μm) according to the following method.

[Measurement of Dispersion Diameter]

[0244] The test piece used for measurement of tanδ was frozen and broken using liquid nitrogen, then the cross section was etched with xylene and coated with platinum by vapor deposition to prepare a sample, which was observed with SEM. On the resultant image, the diameter of 50 holes formed by etching was measured, and the resultant data were averaged to give an average value of a volume-average dispersion medium. The results are shown in Table 5.

[Measurement of Tanδ Intensity (Shear, 1 Hz)]

[0245] This was measured according to JIS K 7244-10 (2005). Specifically, the resultant sheet was cut into a disc having a diameter of 8 mm to be a sample, and using a strain control type dynamic viscoelasticity device “ARES-G2” (by TA Instrument Japan Corporation), and while given oscillation at a strain of 0.1% and at a frequency of 1 Hz, this was heated from −70° C. up to 100° C. at a constant rate of 3° C./min to measure the tanδ intensity of the sheet at 0° C., 10° C., 20° C., 30° C. and 40° C., and the maximum value of tanδ intensity at 0° C. to 40° C. was determined. A higher tanδ intensity means more excellent vibration-damping performance. The results are shown in Table 4 and Table 5.

TABLE-US-00005 TABLE 4 Example Example Example Example Example Comparative Comparative Reference 1 2 3 4 5 Example 1 Example 2 Example 1 Resin A-1 90 80 80 90 80 80 100 — Composition B-1 10 20 10 — — — — 50 (part by B-2 — — — 10 20 — — — mass) B-3 — — 10 — — 20 — 50 tanδ (0° C.) 0.08 0.10 0.17 0.07 0.07 0.09 0.07 0.59 tanδ (10° C.) 0.15 0.28 0.25 0.05 0.05 0.07 0.05 0.93 tanδ (20° C.) 0.14 0.27 0.13 0.05 0.06 0.05 0.03 0.49 tanδ (30° C.) 0.09 0.15 0.08 0.15 0.25 0.05 0.03 0.30 tanδ (40° C.) 0.05 0.08 0.08 0.18 0.27 0.06 0.03 0.18 Maximum value of tanδ 0.19 0.31 0.26 0.18 0.28 0.10 0.07 1.03 intensity at 0° C. to 40° C. Ratio of maximum value of 31 31 15 30 30 5 — — tanδ intensity at 0 to 40° C. of (B) to maximum value of tanδ intensity at 0 to 40° C. of (A) (tanδ(B) max/tanδ(A) max)

TABLE-US-00006 TABLE 5 Comparative Example 6 Example 7 Example 8 Example 9 Example 10 Example 1 Resin A-1 80 80 80 80 80 80 Composition B-1 20 20 20 20 20 — (part by mass) B-3 — — — — — 20 C-1 1 3 5 — — — C-2 — — — 3 — — C-3 — — — — 3 — Dispersion diameter (μm) 7 5 5 8 5 13 tanδ (0° C.) 0.09 0.10 0.10 0.11 0.09 0.09 tanδ (10° C.) 0.26 0.28 0.29 0.27 0.26 0.07 tanδ (20° C.) 0.29 0.30 0.27 0.27 0.28 0.05 tanδ (30° C.) 0.14 0.17 0.15 0.16 0.15 0.05 tanδ (40° C.) 0.08 0.09 0.08 0.07 0.09 0.06 Maximum value of tanδ intensity at 0.32 0.31 0.32 0.32 0.33 0.10 0° C. to 40° C. Ratio of maximum value of tanδ 31 31 31 31 31 5 intensity at 0 to 40° C. of (B) to maximum value of tanδ intensity at 0 to 40° C. of (A) (tanδ(B)max/tanδ(A)max)

[0246] Components shown in Tables 4 and 5 are as described below. A-1: Hytrel 3046 by Du Pont-Toray Co., Ltd. (polyester-based thermoplastic elastomer (A): TPEE)

[0247] A maximum value of the tanδ intensity at 0 to 40° C. of the above A-1 was measured in the same measurement method as that for the hydrogenated aromatic vinyl compound-based elastomer (B), and was 0.07.

B-1: Hydrogenated aromatic vinyl compound-based elastomer (B) produced in Production Example 1
B-2: Hydrogenated aromatic vinyl compound-based elastomer (B) produced in Production Example 2
B-3: Hydrogenated aromatic vinyl compound-based elastomer (B) produced in Production Example 3
C-1: Compatibilizer: Bond Fast BF-7M by Sumitomo Chemical Co., Ltd., ethylene-glycidyl methacrylate copolymer
C-2: Compatibilizer: Bond Fast BF-E by Sumitomo Chemical Co., Ltd., ethylene-glycidyl methacrylate copolymer
C-3: Compatibilizer: Epofriend AT501 by Daicel Corporation, epoxidized styrene-butadiene block copolymer

[0248] From Tables 4 and 5, it is known that the thermoplastic elastomer composition containing the polyester-based thermoplastic elastomer (A) and the hydrogenated aromatic vinyl compound-based elastomer (B) which is a hydrogenate of a block copolymer containing a polymer block (a) having a structural unit derived from an aromatic vinyl compound (styrene) and a polymer block (b) having a structural unit derived from a conjugated diene (isoprene, or isoprene and butadiene) and which has a glass transition temperature of −10 to 40° C., in a ratio by mass (A/B) of 99/1 to 1/99 can have improved vibration-damping performance while retaining the properties inherent in the polyester-based thermoplastic elastomer (A).

[0249] From Table 4, it is known that Examples 1 to 3 containing the hydrogenated aromatic vinyl compound-based elastomer (B-1) obtained by using both isoprene and butadiene attained a high tanδ at 0° C. to 20° C. than Examples 4 to 5 containing the hydrogenated aromatic vinyl compound-based elastomer (B-2) obtained by using butadiene alone, and it is also known that Examples 4 to 5 containing the hydrogenated aromatic vinyl compound-based elastomer (B-2) obtained by using butadiene alone attained a high tanδ at 30° C. to 40° C. than Examples 1 to 3 containing the hydrogenated aromatic vinyl compound-based elastomer (B-1) obtained by using both isoprene and butadiene.

[0250] From Table 5, it is known that, in the case where the compatibilizer was added, even when the amount added of the compatibilizer was varied within a range of 1 part by mass to 3 parts by mass relative to 100 parts by mass of the total of the polyester-based thermoplastic elastomer (A) and the hydrogenated aromatic vinyl compound-based elastomer (B) (Examples 6 to 8), the value of tanδ did not change greatly, and it is also known that, in the case where the compatibilizer was added, even when the kind of the compatibilizer changed among C-1 to C-3 (Examples 7, 9, 10), the value of tanδ did not change greatly.

INDUSTRIAL APPLICABILITY

[0251] The thermoplastic elastomer composition of the present invention can have improved vibration-damping properties while retaining the properties inherent in the polyester-based thermoplastic elastomer (A), and therefore can be favorably used for, for example, vibration-damping materials, gears and composite molded objects.