Thermoplastic elastomer composition and molded article

Abstract

A thermoplastic elastomer composition obtained by blending a polyamide resin (A) and a thermoplastic elastomer (B), the thermoplastic elastomer composition having a loss tangent of 0.10 or more at a frequency of 100 Hz and a temperature of 23 DEG C and a melting point of 200 DEG C or more as measured by differential scanning calorimetry (DSC). Provided is a thermoplastic elastomer composition which can be easily molded, has excellent vibration damping properties, spinnability, high-temperature rigidity, and blocking resistance, and can be used as a sound-absorbing member and a vibration-damping member in harsh temperature environments.

Description

Technical Field

[0001] The present invention relates to a thermoplastic elastomer composition comprising a mixture of a polyamide resin (A) and a thermoplastic elastomer (B), and a molded article using the thermoplastic elastomer composition. Background Art

[0002] Traditionally, flexible polymer materials made by mixing crosslinking agents, reinforcing agents, and other agents into rubbers such as natural or synthetic rubber and then crosslinking them under high temperature and high pressure have been widely used. However, these rubbers require long-term crosslinking and molding processes under high temperature and high pressure, resulting in poor processability. Furthermore, since crosslinked rubber lacks thermoplastic properties, it cannot generally be recycled like thermoplastic resins. Consequently, in recent years, a variety of thermoplastic elastomers have been developed that can be easily molded using common melt molding techniques, such as injection molding, hot press molding, and extrusion molding, similar to conventional thermoplastic resins.

[0003] Patent Document 1 discloses a thermoplastic resin composition having a good balance between rigidity and impact resistance, comprising as main components a modified conjugated diene polymer having at least one group selected from an alkoxysilyl group, an amino group, an acid anhydride group, and a carboxyl group, and a polar resin.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-291117

[0007] Summary of the Invention

[0008] Problems to be solved by the invention

[0009] However, the example specifically disclosed in Patent Document 1 is a resin composition comprising a diene copolymer having a reactive functional group and polyamide 6. The loss tangent of the resin composition at 23° C. is low, and excellent vibration damping properties cannot be obtained, making it insufficient for use as a sound absorbing member or a vibration damping member.

[0010] An object of the present invention is to provide a thermoplastic elastomer composition that can be easily molded and used as a sound absorbing member or a vibration damping member under a severe temperature environment.

[0011] Means for solving problems

[0012] In order to solve the above-mentioned problems, the present invention has the following configurations.

[0013] (1) A thermoplastic elastomer composition comprising a polyamide resin (A) and a thermoplastic elastomer (B), wherein the composition has a loss tangent of 0.10 or greater at a frequency of 100 Hz and a temperature of 23° C. and a melting point of 200° C. or greater as measured by differential scanning calorimetry (DSC).

[0014] (2) The thermoplastic elastomer composition according to (1), wherein the weight ratio of the polyamide resin (A) to the thermoplastic elastomer (B) contained in the thermoplastic elastomer composition is (A):(B) = 40:60 to 90:10.

[0015] (3) The thermoplastic elastomer composition according to (1) or (2), wherein the polyamide resin (A) is a polyamide resin (A1) having a melting point of 200° C. or higher as measured by differential scanning calorimetry (DSC).

[0016] (4) The thermoplastic elastomer composition according to any one of (1) to (3), wherein the thermoplastic elastomer (B) is at least one selected from the group consisting of a copolymer (B1) and a copolymer (B2), wherein the copolymer (B1) is a copolymer having a reactive functional group and comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof, and wherein the copolymer (B2) is a copolymer other than the component (B1) and comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof.

[0017] (5) The thermoplastic elastomer composition according to any one of (1) to (3), wherein the thermoplastic elastomer composition comprises a polyamide resin (A1), a copolymer (B1), and a copolymer (B2-1), wherein the polyamide resin (A1) has a melting point of 200°C or higher as measured by differential scanning calorimetry (DSC), the copolymer (B1) is a copolymer having reactive functional groups and comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof, and the copolymer (B2-1) is a copolymer having a reactive functional group and comprising a polymer block mainly composed of an aromatic vinyl compound. A copolymer other than the component (B1) containing a polymer block mainly composed of a base compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof, and having a glass transition temperature higher than -20°C, wherein the weight ratio of the polyamide resin (A1), the copolymer (B1) and the copolymer (B2-1) contained in the thermoplastic elastomer composition satisfies the following relationship: (A1):(B1)=50:50 to 80:20, (B1):(B2-1)=90:10 to 25:75, and (A1):((B1)+(B2-1))=40:60 to 70:30.

[0018] (6) The thermoplastic elastomer composition according to (5), further comprising a hydrogenated petroleum resin (C), wherein the content of the hydrogenated petroleum resin (C) is 0.01 to 20 parts by weight relative to 100 parts by weight of the total of the polyamide resin (A1), the copolymer (B1), and the copolymer (B2-1).

[0019] (7) The thermoplastic elastomer composition according to any one of (1) to (3), wherein the thermoplastic elastomer composition comprises a polyamide resin (A1), a copolymer (B1), and a hydrogenated petroleum resin (C), wherein the polyamide resin (A1) has a melting point of 200°C or higher as measured by differential scanning calorimetry (DSC), and the copolymer (B1) is a copolymer having a reactive functional group and comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof, wherein the weight ratio of the polyamide resin (A1) to the copolymer (B1) in the thermoplastic elastomer composition is (A1):(B1) = 50:50 to 90:10, and the content of the hydrogenated petroleum resin (C) is 0.01 to 20 parts by weight relative to 100 parts by weight of the total of the polyamide resin (A1) and the copolymer (B1).

[0020] (8) The thermoplastic elastomer composition according to any one of (1) to (3), wherein the thermoplastic elastomer composition comprises a polyamide resin (A1), a copolymer (B1-1), a copolymer (B2-2), and a hydrogenated petroleum resin (C), wherein the polyamide resin (A1) has a melting point of 200°C or higher as measured by differential scanning calorimetry (DSC), the copolymer (B1-1) is a copolymer having a reactive functional group and having a glass transition temperature of -40°C or lower and comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof; and the copolymer (B2-2) is a copolymer having a polymer block mainly composed of an aromatic vinyl compound and a hydrogenated product thereof. A copolymer other than the component (B1-1) comprising a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof, wherein the glass transition temperature is not more than -20°C, the weight ratio of the polyamide resin (A1), the copolymer (B1-1) and the copolymer (B2-2) satisfying the following relationships: (A1):(B1-1)=50:50 to 80:20, (B1-1):(B2-2)=90:10 to 25:75, and (A1):((B1-1)+(B2-2))=40:60 to 65:35, and the content of the hydrogenated petroleum resin (C) is 0.01 to 20 parts by weight relative to 100 parts by weight of the total of the polyamide resin (A1), the copolymer (B1-1) and the copolymer (B2-2).

[0021] (9) The thermoplastic elastomer composition according to any one of (4) to (8), wherein the polymer block mainly composed of a conjugated diene compound and / or its hydrogenated product is a polymer block derived from at least one selected from isoprene, butadiene, ethylene / butylene, and ethylene / propylene.

[0022] (10) A molded article made from the thermoplastic elastomer composition according to any one of (1) to (9).

[0023] (11) The molded article according to (10), which is a sound absorbing member.

[0024] (12) The molded article according to (10), which is a vibration damping member.

[0025] (13) The molded article according to any one of (10) to (12), which is a molded article selected from the group consisting of injection molded articles, fibers, sheets, foamed injection molded articles, and foamed sheets.

[0026] Effects of the Invention

[0027] The thermoplastic elastomer composition of the present invention exhibits excellent vibration damping properties and high-temperature rigidity. Furthermore, the thermoplastic elastomer composition of the present invention exhibits excellent spinnability, film-forming properties, and blocking resistance, and can be easily molded using common melt molding techniques. The thermoplastic elastomer composition of the present invention can be developed for applications such as automotive and electrical / electronic applications. DETAILED DESCRIPTION

[0028] Hereinafter, the present invention will be described in further detail.

[0029] The present invention relates to a thermoplastic elastomer composition comprising a polyamide resin (A) and a thermoplastic elastomer (B). The thermoplastic elastomer composition has a loss tangent of 0.10 or greater at a frequency of 100 Hz and a temperature of 23°C, and a melting point of 200°C or greater as measured by differential scanning calorimetry (DSC).

[0030] The polyamide resin (A) is not particularly limited. Generally, it can be obtained using amino acids, lactams, or diamines and dicarboxylic acids as main raw materials. Representative examples of such raw materials include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and p-aminomethylbenzoic acid; lactams such as ε-caprolactam and ω-laurolactam; aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, and 5-methylnonamethylenediamine; aromatic diamines such as m-xylylenediamine and p-xylylenediamine; 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethyl Alicyclic diamines such as cyclohexane, bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminopropyl)piperazine, and aminoethylpiperazine; aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalate, hexahydroterephthalic acid, and hexahydroisophthalic acid; and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid. Polyamide homopolymers or copolymers derived from these raw materials can be used in the present invention. Two or more of the above-mentioned polyamide resins may be used.

[0031] The polyamide resin (A) used in the present invention is preferably a polyamide resin (A1) having a melting point of 200° C. or higher as measured by DSC.

[0032] Specific examples of the polyamide resin (A1) preferably used in the present invention include polycaprolactam (polyamide 6), polyhexamethylene adipamide (polyamide 66), polybutylene adipamide (polyamide 46), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecanoamide (polyamide 612), polyhexamethylene terephthalamide / polycaprolactam copolymer (polyamide 6T / 6), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (polyamide 66 / 6T), polyhexamethylene adipamide / Polyhexamethylene isophthalamide copolymer (polyamide 66 / 6I), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6T / 6I), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 6T / 6I), polyhexamethylene terephthalamide / poly(2-methylpentamethylene terephthalamide) copolymer (polyamide 6T / M5T), polyxylylene adipamide (polyamide XD6), and mixtures or copolymers thereof. Particularly preferred examples include polyamide 6, polyamide 610, and polyamide 66, with polyamide 6 being a more preferred example.

[0033] The melting point of the polyamide resin (A1) in the present invention, as measured by DSC, can be determined by the following method. First, a differential scanning calorimeter (DSC-7, manufactured by PerkinElmer) is used to perform a two-point calibration (indium and lead) and baseline correction. An 8-10 mg sample of the polyamide resin is weighed and heated at a rate of 20°C / minute. The melting endothermic peak observed during the heating process is defined as the melting point.

[0034] If the melting point of the polyamide resin (A1) is lower than 200°C, the high-temperature rigidity of the thermoplastic elastomer composition of the present invention decreases. Therefore, the melting point of the polyamide resin (A1) is more preferably 205°C or higher, and even more preferably 210°C or higher.

[0035] On the other hand, the upper limit of the melting point of the polyamide resin (A1) is not particularly limited, but is preferably 350°C or lower because decomposition of the thermoplastic elastomer (B) tends to be suppressed without deteriorating mechanical properties. It is more preferably 320°C or lower, and even more preferably 300°C or lower.

[0036] Examples of means for adjusting the melting point of the polyamide resin (A1) to the above range include a method of selecting a material having a desired melting point from polyamide resins having different melting points, and a method of adjusting the polymerization degree and copolymerization ratio of the polyamide resin.

[0037] The degree of polymerization of the polyamide resin (A) is not particularly limited, but preferably has a relative viscosity of 1.5 to 7.0, as measured in a 98% concentrated sulfuric acid solution at 25°C at a resin concentration of 0.01 g / ml. A relative viscosity of 1.5 or greater provides a suitably high melt viscosity of the thermoplastic elastomer composition during molding, suppressing air entrapment during molding and further improving moldability. On the other hand, a relative viscosity of 7.0 or less provides a suitably low melt viscosity of the thermoplastic elastomer composition during molding, further improving moldability.

[0038] The amount of amino terminal groups in the polyamide resin (A) is not particularly limited, but is preferably within the range of 1.0×10 -5 ~12.0×10 -5 mol / g range. If the amino terminal group content is 1.0×10 -5 ~12.0×10 -5 mol / g range, a sufficient degree of polymerization can be achieved, leading to improved mechanical strength of the molded article. The amino terminal group content of the polyamide resin (A) can be determined by dissolving the polyamide resin (A) in a phenol / ethanol mixed solvent (83.5:16.5 (volume ratio)) and titrating with 0.02N aqueous hydrochloric acid.

[0039] Examples of the thermoplastic elastomer (B) that can be used in the present invention include olefin resins, acrylic rubbers, silicone rubbers, fluororubbers, nitrile rubbers, ethylene rubbers, urethane rubbers, styrene elastomers, polyamide elastomers, polyester elastomers, and ionomers. Two or more of these may be mixed.

[0040] Among these, styrene-based elastomers are preferably used due to their excellent compatibility with the polyamide resin (A) and their good vibration damping improvement effect. The styrene-based elastomer is preferably at least one selected from the group consisting of a copolymer (B1) comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof, and having a reactive functional group (hereinafter sometimes referred to as copolymer (B1)), and a copolymer (B2) comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof, excluding component (B1) (hereinafter sometimes referred to as copolymer (B2)).

[0041] Here, the polymer block mainly composed of an aromatic vinyl compound means a polymer block in which 60 wt % or more, preferably 70 wt % or more, more preferably 80 wt % or more of the units constituting the polymer block are units derived from the aromatic vinyl compound.

[0042] Examples of the aromatic vinyl compounds include styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,6-dimethylstyrene, 2,4-dimethylstyrene, α-methyl-o-methylstyrene, α-methyl-m-methylstyrene, α-methyl-p-methylstyrene, β-methyl-o-methylstyrene, β-methyl-m-methylstyrene, β-methyl-p-methylstyrene, 2,4,6-trimethylstyrene, α-methyl-2,6-dimethylstyrene, α-methyl-2,4-dimethylstyrene, β-methyl-2,6-dimethylstyrene, β-methyl-2,4-dimethylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, 2,6-dichlorostyrene, 2,4-dichlorostyrene, α-chloro-o-chlorostyrene, α-chloro-m-chlorostyrene, α-chloro-p-chlorostyrene, β-chloro-o-chlorostyrene, β-chloro-m-chlorostyrene, β-chloro-p-chlorostyrene, 2,4,6-trichlorostyrene, α-chloro-2,6-dichlorostyrene, α-chloro-2,4-dichlorostyrene, β-chloro-2,6-dichlorostyrene, β-chloro-2,4-dichlorostyrene, o-tert-butylstyrene, m-tert-butylstyrene, p-tert-butylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-chloromethylstyrene, m-chloromethylstyrene, p-chloromethylstyrene, o-bromomethylstyrene, m-bromomethylstyrene, p-bromomethylstyrene, silyl-substituted styrene derivatives, indene, vinylnaphthalene, etc. Among these, styrene, α-methylstyrene, or mixtures thereof are preferred from the viewpoints of industrial availability and glass transition temperature.

[0043] The polymer block mainly composed of a conjugated diene compound means a polymer block in which 60% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more of the units constituting the polymer block are units derived from the conjugated diene compound.

[0044] Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 1,3-hexadiene, and hydrogenated products thereof. One or more of these compounds may be selected and used.

[0045] Preferably, it is at least one selected from the group consisting of isoprene, butadiene, ethylene / butene which are hydrogenated products of butadiene, and ethylene / propylene which are hydrogenated products of isoprene.

[0046] The ratio of the polymer block mainly composed of an aromatic vinyl compound to the polymer block mainly composed of a conjugated diene compound constituting the copolymer (B1) is not particularly limited, but from the perspective of loss tangent, the content of the polymer block mainly composed of an aromatic vinyl compound in the copolymer (B1) is preferably 10 to 70% by weight. If the content of the polymer block mainly composed of an aromatic vinyl compound is 10% by weight or greater, sufficient mechanical properties are exhibited, while if it is 70% by weight or less, a high loss tangent can be achieved.

[0047] The molecular weight of copolymer (B1) is not particularly limited, but from the perspectives of moldability, fluidity, rubber elasticity, etc., the weight-average molecular weight measured by GPC is preferably 5,000 to 400,000, and more preferably 10,000 to 200,000. A weight-average molecular weight of 5,000 or greater exhibits sufficient mechanical properties. On the other hand, a weight-average molecular weight of 400,000 or less provides excellent moldability and fluidity of the resulting molded article.

[0048] The reactive functional group in the copolymer (B1) is not particularly limited, and examples thereof include amino groups, carboxyl groups, carboxyl metal salts, hydroxyl groups, acid anhydride groups, epoxy groups, isocyanate groups, mercapto groups, Among them, it is preferred to use at least one selected from amino, carboxyl, carboxyl metal salt, epoxy, acid anhydride and At least one oxazoline group is used because the reactivity is high and side reactions such as decomposition and cross-linking are rare.

[0049] Examples of the acid anhydride constituting the acid anhydride group include maleic anhydride, itaconic anhydride, nadic anhydride, citraconic anhydride, and 1-butene-3,4-dicarboxylic anhydride. Two or more of these may be used simultaneously. Among these, maleic anhydride and itaconic anhydride are particularly suitable.

[0050] The amount of the reactive functional groups introduced into the copolymer (B1) is preferably 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and even more preferably 0.5 to 3 parts by weight, relative to 100 parts by weight of the copolymer (B1). By setting the amount of the reactive functional groups to 0.1 parts by weight or greater, the reactivity with the polyamide resin (A) can be improved. On the other hand, if the amount of the reactive functional groups exceeds 20 parts by weight, the reaction between the polyamide resin (A) and the copolymer (B1) may proceed excessively, resulting in a decrease in the high-temperature rigidity of the thermoplastic elastomer composition.

[0051] The copolymer (B2) usable in the present invention is a copolymer other than component (B1) that includes a polymer block primarily composed of an aromatic vinyl compound and a polymer block primarily composed of a conjugated diene compound and / or a hydrogenated product thereof. Specifically, it is a copolymer that includes a polymer block primarily composed of an aromatic vinyl compound and a polymer block primarily composed of a conjugated diene compound and / or a hydrogenated product thereof, and that does not have a reactive functional group.

[0052] As the aromatic vinyl compound in the copolymer (B2), the same aromatic vinyl compound as described above for the copolymer (B1) is preferred.

[0053] The polymer block mainly composed of a conjugated diene compound and / or its hydrogenated product in the copolymer (B2) is preferably the same as the polymer block mainly composed of a conjugated diene compound and / or its hydrogenated product described above for the copolymer (B1).

[0054] The block copolymer (B2) of the present invention is not particularly limited in structure as long as it is composed of a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or their hydrogenated products. For example, a linear, branched, or star-shaped structure may be selected.

[0055] The ratio of the polymer block primarily composed of an aromatic vinyl compound to the polymer block primarily composed of a conjugated diene compound constituting copolymer (B2) is not particularly limited, but from the perspective of loss tangent, the content of the polymer block primarily composed of an aromatic vinyl compound in copolymer (B2) is preferably 10 to 70% by weight. If the content of the polymer block primarily composed of an aromatic vinyl compound is 10% by weight or greater, sufficient mechanical properties are exhibited, while a content of 70% by weight or less can increase the loss tangent.

[0056] The molecular weight of the copolymer (B2) is not particularly limited, but from the perspectives of molding processability, fluidity, rubber elasticity, etc., the weight average molecular weight measured by GPC is preferably 5,000 to 400,000, and more preferably 10,000 to 200,000. A weight average molecular weight of 5,000 or greater exhibits sufficient mechanical properties, while a weight average molecular weight of 400,000 or less results in excellent processability and fluidity of the molded article.

[0057] In addition, in this invention, the compound which corresponds to both (B1) component and (B2) component and has a reactive functional group is regarded as (B1) component.

[0058] Regarding the blending amounts of the polyamide resin (A) and the thermoplastic elastomer (B) contained in the thermoplastic elastomer composition of the present invention, the weight ratio (A):(B) of the polyamide resin (A) to the thermoplastic elastomer (B) is preferably 40:60 to 90:10. If the thermoplastic elastomer (B) is greater than the ratio of (A):(B) of 40:60, the high-temperature rigidity of the polyamide resin is less readily exhibited, resulting in low high-temperature rigidity of the thermoplastic elastomer composition. On the other hand, if the thermoplastic elastomer (B) is less than the ratio of (A):(B) of 90:10, the loss tangent of the thermoplastic elastomer composition is low, making it difficult to impart vibration damping properties. The weight ratio (A):(B) is more preferably 40:60 to 85:15, and even more preferably 40:60 to 80:20.

[0059] The thermoplastic elastomer composition of the present invention has a loss tangent of 0.10 or higher at a frequency of 100 Hz and a temperature of 23° C., and has a melting point of 200° C. or higher as measured by differential scanning calorimetry (DSC).

[0060] When the loss tangent at a frequency of 100 Hz and a temperature of 23° C. is 0.10 or more, vibration damping properties and sound absorbing properties can be imparted to a molded article formed from the thermoplastic elastomer composition.

[0061] The loss tangent at a frequency of 100 Hz and a temperature of 23°C can be determined by the following method. Using the thermoplastic elastomer composition of the present invention, a thin rectangular molded article is produced as described below. This molded article is measured using a viscoelasticity measuring instrument (Seiko Instruments Inc., DMS6100) under a nitrogen atmosphere at a heating rate of 2°C / minute and a frequency of 100 Hz to determine the storage modulus and loss modulus. The loss tangent at 23°C is calculated by dividing the loss modulus at 23°C by the storage modulus.

[0062] The loss tangent at a frequency of 100 Hz and a temperature of 23° C. is preferably 0.15 or greater, more preferably 0.18 or greater.

[0063] The upper limit of the loss tangent at a frequency of 100 Hz and a temperature of 23° C. is not particularly limited, but is preferably 5.0 or less from the viewpoint of shape retention of the molded article.

[0064] Furthermore, by having a melting point of 200° C. or higher as measured by differential scanning calorimetry (DSC), high-temperature rigidity can be imparted to a molded article formed from the thermoplastic elastomer composition, thereby maintaining the shape of the molded article.

[0065] The melting point measured by DSC can be determined by the following method. First, a differential scanning calorimeter (DSC-7, manufactured by PerkinElmer) is used for two-point calibration (indium and lead) and baseline correction. An 8-10 mg sample of the thermoplastic elastomer composition is weighed and heated at a rate of 20°C / minute. The melting endotherm observed during the heating process is taken as the melting point.

[0066] The melting point of the thermoplastic elastomer composition is preferably 205°C or higher, more preferably 210°C or higher.

[0067] On the other hand, the upper limit of the melting point of the thermoplastic elastomer composition is not particularly limited, but is preferably 350°C or lower, more preferably 320°C or lower, and even more preferably 300°C or lower from the viewpoint of productivity.

[0068] The method for obtaining a thermoplastic elastomer composition having a loss tangent of 0.10 or greater at a frequency of 100 Hz and a temperature of 23°C and a melting point of 200°C or greater as measured by differential scanning calorimetry (DSC) is not particularly limited as long as such a thermoplastic elastomer composition can be obtained. However, the following thermoplastic elastomer composition is preferably used.

[0069] The thermoplastic elastomer composition according to the first embodiment of the present invention includes a thermoplastic elastomer composition comprising a polyamide resin (A1), a copolymer (B1), and a copolymer (B2-1), wherein the polyamide resin (A1) has a melting point of 200° C. or higher as measured by differential scanning calorimetry (DSC), the copolymer (B1) is a copolymer having a reactive functional group and comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof, and the copolymer (B2-1) is a copolymer comprising: A copolymer other than component (B1) comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof, wherein the glass transition temperature is higher than -20°C, and the weight ratio of the polyamide resin (A1), the copolymer (B1) and the copolymer (B2-1) satisfies the following conditions: (A1):(B1)=50:50 to 80:20, (B1):(B2-1)=90:10 to 25:75, and (A1):((B1)+(B2-1))=40:60 to 70:30.

[0070] By blending a copolymer (B1) having a reactive functional group with a polyamide resin (A1) having excellent high-temperature rigidity and moldability at a specific ratio, the polyamide resin (A1) and the copolymer (B1) react appropriately, improving the compatibility between the polyamide resin (A1) and the copolymer (B2-1). Furthermore, by blending the copolymer (B1) and the copolymer (B2-1) at a specific ratio, the copolymer (B1) and the copolymer (B2-1) interact appropriately, further improving the compatibility between the polyamide resin (A1) and the copolymer (B2-1), and improving the loss tangent of the thermoplastic elastomer composition. A high loss tangent of the thermoplastic elastomer composition results in a thermoplastic elastomer composition with excellent vibration damping properties. Furthermore, by blending a copolymer (B2-1) having a glass transition temperature higher than -20°C in addition to the polyamide resin (A1) and the copolymer (B1) at a specific ratio, the loss tangent of the thermoplastic elastomer composition can be improved while maintaining the high-temperature rigidity of the polyamide resin.

[0071] The polyamide resin (A1) used in this embodiment is a polyamide resin having a melting point of 200° C. or higher as measured by DSC. The polyamide resin (A1) used in this embodiment is preferably the same as the polyamide resin (A1) described above.

[0072] The copolymer (B1) used in this embodiment is preferably the same as the copolymer (B1) described above.

[0073] The glass transition temperature of the copolymer (B1) in this embodiment is not particularly limited, but is preferably higher than -60°C. A glass transition temperature of the copolymer (B1) higher than -60°C can increase the loss tangent of the thermoplastic elastomer composition at a frequency of 100 Hz and a temperature of 23°C.

[0074] The glass transition temperature of the copolymer (B1) is higher than -60°C, preferably -30°C or higher, and more preferably -20°C or higher.

[0075] The glass transition temperature of copolymer (B1) can be determined by the following method. A sample kept in an absolute dry state is measured using a viscoelasticity measuring instrument (DMS6100, manufactured by Seiko Instruments Inc.) under a nitrogen atmosphere at a frequency of 100 Hz and a heating rate of 2°C / minute to determine the storage modulus and loss modulus. The loss modulus is divided by the storage modulus to determine the loss tangent. The temperature at the peak of the loss tangent obtained is defined as the glass transition temperature.

[0076] Examples of methods for adjusting the glass transition temperature of the copolymer (B1) to fall within the above range include methods of adjusting the structures and copolymerization ratios of the copolymer components of the copolymer (B1).

[0077] The copolymer (B2-1) used in this embodiment refers to a copolymer other than component (B1) that comprises a polymer block primarily composed of an aromatic vinyl compound and a polymer block primarily composed of a conjugated diene compound and / or a hydrogenated product thereof. Specifically, it is a copolymer that comprises a polymer block primarily composed of an aromatic vinyl compound and a polymer block primarily composed of a conjugated diene compound and / or a hydrogenated product thereof, and that does not have any reactive functional groups.

[0078] As the aromatic vinyl compound in the copolymer (B2-1), the same compounds as those described above for the copolymer (B1) are preferred.

[0079] The polymer block mainly composed of a conjugated diene compound and / or its hydrogenated product in the copolymer (B2-1) is preferably the same as the polymer block mainly composed of a conjugated diene compound and / or its hydrogenated product described above for the copolymer (B1).

[0080] The block copolymer (B2-1) of this embodiment is not particularly limited in structure as long as it is composed of a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or their hydrogenated products. For example, linear, branched, or star-shaped structures may be selected.

[0081] The ratio of the polymer block primarily composed of an aromatic vinyl compound to the polymer block primarily composed of a conjugated diene compound constituting the copolymer (B2-1) is not particularly limited, but from the perspective of loss tangent, the content of the polymer block primarily composed of an aromatic vinyl compound in the copolymer (B2-1) is preferably 10 to 70% by weight. A polymer block primarily composed of an aromatic vinyl compound having a content of 10% by weight or greater exhibits sufficient mechanical properties, while a content of 70% by weight or less improves the loss tangent.

[0082] The molecular weight of the copolymer (B2-1) is not particularly limited, but is preferably 5,000 to 400,000, more preferably 10,000 to 200,000, as measured by GPC, in view of molding processability, fluidity, rubber elasticity, and the like. A weight-average molecular weight of 5,000 or greater exhibits sufficient mechanical properties, while a weight-average molecular weight of 400,000 or less provides excellent processability and fluidity of the molded article.

[0083] In addition, in this embodiment, the compound which corresponds to both the component (B1) and the component (B2-1) and has a reactive functional group is regarded as the component (B1).

[0084] The glass transition temperature of the copolymer (B2-1) in this embodiment is higher than -20°C. When the glass transition temperature of the copolymer (B2-1) is higher than -20°C, the loss tangent of the thermoplastic elastomer composition at a frequency of 100 Hz and a temperature of 23°C can be increased.

[0085] The glass transition temperature of the copolymer (B2-1) is higher than -20°C, preferably -15°C or higher, and more preferably -10°C or higher.

[0086] The glass transition temperature of copolymer (B2-1) can be determined by the following method. A sample kept in an absolute dry state is measured using a viscoelasticity measuring instrument (DMS6100, manufactured by Seiko Instruments Inc.) under a nitrogen atmosphere at a frequency of 100 Hz and a heating rate of 2°C / minute to determine the storage modulus and loss modulus. The loss modulus is divided by the storage modulus to determine the loss tangent. The temperature at the peak of the loss tangent obtained is defined as the glass transition temperature.

[0087] Examples of methods for adjusting the glass transition temperature of the copolymer (B2-1) to fall within the above range include methods of adjusting the structures and copolymerization ratios of the copolymer components of the copolymer (B2-1).

[0088] Regarding the blending amounts of the polyamide resin (A1), copolymer (B1), and copolymer (B2-1) contained in the thermoplastic elastomer composition of this embodiment, the ratio (weight ratio) of polyamide resin (A1) to copolymer (B1) (A1):(B1) is 50:50 to 80:20, the ratio (weight ratio) of copolymer (B1) to copolymer (B2-1) (B1):(B2-1) is 90:10 to 25:75, and the ratio (weight ratio) of polyamide resin (A1) to the total of copolymer (B1) and copolymer (B2-1) (A1):((B1) + (B2-1)) is 40:60 to 70:30. If the ratio of copolymer (B1) to (A1):(B1) exceeds 50:50, the reaction between the polyamide resin (A1) and the copolymer (B1) proceeds excessively, the high-temperature rigidity of the polyamide resin is not readily exhibited, and the high-temperature rigidity of the thermoplastic elastomer composition is low. On the other hand, if the copolymer (B1) content is less than 80:20 (the ratio of (A1):(B1)), the compatibility between the polyamide resin (A1) and the copolymer (B2-1) decreases. The (A1):(B1) ratio is 50:50 to 80:20, preferably 55:45 to 80:20, more preferably 58:42 to 80:20, and even more preferably 60:40 to 80:20. Furthermore, if the copolymer (B2-1) content is less than 90:10 (the ratio of (B1):(B2-1)), the excellent loss tangent of the copolymer (B2-1) is not exhibited. On the other hand, if the copolymer (B1) content is less than 25:75 (the ratio of (B1):(B2-1), the reactivity of the polyamide resin (A1) with the copolymer (B1) decreases, compatibility with the copolymer (B2-1) decreases, and the loss tangent of the thermoplastic elastomer composition decreases. The ratio of (B1):(B2-1) is in the range of 90:10 to 25:75, preferably 90:10 to 30:70, more preferably 90:10 to 35:65, and even more preferably 90:10 to 40:60. Furthermore, if the ratio of ((B1) + (B2-1)) to (A1):((B1) + (B2-1)) is greater than 40:60, the high-temperature rigidity of the polyamide resin (A1) is not easily exhibited, resulting in low high-temperature rigidity of the thermoplastic elastomer composition. Furthermore, if the ratio of ((B1) + (B2-1)) to (A1):((B1) + (B2-1)) is less than 70:30, the loss tangent of the thermoplastic elastomer composition is low, making it difficult to impart vibration damping properties. The ratio of (A1):((B1)+(B2-1)) is in the range of 40:60 to 70:30, preferably 42:58 to 70:30, more preferably 45:55 to 70:30, and even more preferably 45:55 to 68:32.

[0089] The thermoplastic elastomer composition of this embodiment preferably further contains a hydrogenated petroleum resin (C).

[0090] Hydrogenated petroleum resin (C) refers to a resin obtained by hydrogenating a petroleum resin obtained by solidifying the remaining fraction after thermal decomposition of naphtha and collection of necessary fractions, without separating unsaturated hydrocarbons mainly from the C5 and C9 fractions, using an acidic catalyst.

[0091] Examples of the hydrogenated petroleum resin include: hydrogenated dicyclopentadiene resins and partially hydrogenated aromatic-modified dicyclopentadiene resins, which are C5-based petroleum resins obtained by copolymerizing C5 fractions such as pentene, isoprene, piperine, and 1,3-pentadiene generated by thermal decomposition of naphtha; C9-based hydrogenated petroleum resins obtained by copolymerizing C9 fractions such as indene, vinyltoluene, and α- or β-methylstyrene generated by thermal decomposition of naphtha; and copolymerized hydrogenated petroleum resins of the above-mentioned C5 fractions and the above-mentioned C9 fractions.

[0092] Examples of commercially available hydrogenated dicyclopentadiene resins include Co., Ltd. (Registered trademark) 5300, 5400 series; Eastotac (registered trademark) H series manufactured by Eastman Chemical Japan Ltd.

[0093] Examples of commercially available partially hydrogenated aromatic modified dicyclopentadiene resins include Co., Ltd. (Registered trademark) 5600 series.

[0094] Examples of commercially available C9 hydrogenated petroleum resins include those manufactured by Arakawa Chemical Industries, Ltd. (Registered trademark) P and M series; Polystolyn manufactured by Eastman Chemical Company.

[0095] Examples of the copolymerized hydrogenated petroleum resin of C5 fraction and C9 fraction include: (registered trademark) series. From the viewpoint of compatibility between the copolymer (B1) and (B2-1), a C9-based hydrogenated petroleum resin is preferred.

[0096] The amount of the hydrogenated petroleum resin (C) contained in the thermoplastic elastomer composition of this embodiment is preferably 0.01 to 20 parts by weight relative to 100 parts by weight of the total of the polyamide resin (A1), the copolymer (B1), and the copolymer (B2-1). A blending amount of 0.01 parts by weight or greater can further improve the loss tangent of the thermoplastic elastomer composition at a temperature of 23°C at a measurement frequency of 100 Hz. On the other hand, a blending amount of 20 parts by weight or less can suppress surface stickiness caused by bleed-out, which is therefore preferred. The blending amount of the hydrogenated petroleum resin is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 15 parts by weight, and even more preferably 1.5 to 15 parts by weight.

[0097] The thermoplastic elastomer composition according to the second embodiment of the present invention includes a thermoplastic elastomer composition comprising a polyamide resin (A1), a copolymer (B1), and a hydrogenated petroleum resin (C), wherein the polyamide resin (A1) has a melting point of 200°C or higher as measured by differential scanning calorimetry (DSC), and the copolymer (B1) is a copolymer having a reactive functional group and comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof. The weight ratio of the polyamide resin (A1) to the copolymer (B1) in the thermoplastic elastomer composition is (A1):(B1) = 50:50 to 90:10, and the content of the hydrogenated petroleum resin (C) is 0.01 to 20 parts by weight per 100 parts by weight of the total of the polyamide resin (A1) and the copolymer (B1).

[0098] By blending a copolymer (B1) having reactive functional groups at a specific ratio with a polyamide resin (A1) exhibiting excellent high-temperature rigidity and moldability, the polyamide resin (A1) and the copolymer (B1) react appropriately, improving flexibility while maintaining the high-temperature rigidity of the polyamide. By blending a specific amount of a hydrogenated petroleum resin (C), the glass transition temperature of the copolymer (B1) is shifted toward higher temperatures, improving the loss tangent of the softened thermoplastic elastomer composition at a temperature of 23°C at a frequency of 100 Hz. This high loss tangent of the thermoplastic elastomer composition results in excellent vibration damping properties.

[0099] The polyamide resin (A1) used in this embodiment is a polyamide resin having a melting point of 200° C. or higher as measured by DSC. The polyamide resin (A1) used in this embodiment is preferably the same as the polyamide resin (A1) described above.

[0100] The copolymer (B1) used in this embodiment is preferably the same as the copolymer (B1) described above.

[0101] Regarding the blending amounts of the polyamide resin (A1) and the copolymer (B1) contained in the thermoplastic elastomer composition of this embodiment, the ratio (weight ratio) of polyamide resin (A1) to copolymer (B1) is (A1):(B1) in the range of 50:50 to 90:10. If the copolymer (B1) ratio is greater than 50:50, the reaction between the polyamide resin (A1) and the copolymer (B1) will proceed excessively, the high-temperature rigidity of the polyamide resin will not be readily exhibited, and the high-temperature rigidity of the thermoplastic elastomer composition will be low. On the other hand, if the copolymer (B1) ratio is less than 90:10, the loss tangent of the thermoplastic elastomer composition will be low, making it difficult to impart vibration damping properties. The ratio of (A1):(B1) is 50:50 to 90:10, preferably 55:45 to 90:10, more preferably 55:45 to 85:15, and even more preferably 60:40 to 85:15.

[0102] The thermoplastic elastomer composition of this embodiment contains a hydrogenated petroleum resin (C) in addition to the polyamide resin (A1) and the copolymer (B1).

[0103] The hydrogenated petroleum resin (C) is preferably the same as the hydrogenated petroleum resin (C) described above.

[0104] The content of the hydrogenated petroleum resin (C) in the thermoplastic elastomer composition of this embodiment is 0.01 to 20 parts by weight per 100 parts by weight of the total of the polyamide resin (A1) and the copolymer (B1). If the content is less than 0.01 parts by weight, the glass transition temperature of the copolymer (B1) cannot be shifted to the high temperature side, and the loss tangent of the thermoplastic elastomer composition at a temperature of 23°C at a frequency of 100 Hz does not reach 0.10 or higher, resulting in poor vibration damping properties. On the other hand, if the content exceeds 20 parts by weight, it is not preferred because it causes surface stickiness due to bleed-out. The content of the hydrogenated petroleum resin is preferably 0.01 to 15 parts by weight, more preferably 0.1 to 15 parts by weight, and even more preferably 1.5 to 15 parts by weight.

[0105] The thermoplastic elastomer composition according to the third embodiment of the present invention includes a thermoplastic elastomer composition comprising a polyamide resin (A1), a copolymer (B1-1), a copolymer (B2-2), and a hydrogenated petroleum resin (C), wherein the polyamide resin (A1) has a melting point of 200°C or higher as measured by differential scanning calorimetry (DSC), the copolymer (B1-1) is a copolymer having a reactive functional group and a glass transition temperature of -40°C or lower, comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof, and the copolymer (B2-2) is a copolymer having a reactive functional group and a glass transition temperature of -40°C or lower, and the copolymer (B2-2) is a copolymer having a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound. A copolymer other than the component (B1-1) containing a polymer block and / or a hydrogenated product thereof as a main component, and having a glass transition temperature of -20°C or lower, wherein the weight ratio of the polyamide resin (A1), the copolymer (B1-1) and the copolymer (B2-2) contained in the thermoplastic elastomer composition satisfies the following relationships: (A1):(B1-1)=50:50 to 80:20, (B1-1):(B2-2)=90:10 to 25:75, (A1):((B1-1)+(B2-2))=40:60 to 65:35, and the content of the hydrogenated petroleum resin (C) is 0.01 to 20 parts by weight relative to 100 parts by weight of the total of the polyamide resin (A1), the copolymer (B1-1) and the copolymer (B2-2).

[0106] By blending a copolymer (B1-1) having a reactive functional group at a specific ratio with a polyamide resin (A1) having excellent high-temperature rigidity and moldability, the polyamide resin (A1) and the copolymer (B1-1) react appropriately, improving the compatibility between the polyamide resin (A1) and the copolymer (B2-2). Furthermore, by blending the copolymer (B1-1) and the copolymer (B2-2) at a specific ratio, the copolymer (B1-1) and the copolymer (B2-2) interact appropriately, improving the compatibility between the polyamide resin (A1) and the copolymer (B2-2), and enhancing the flexibility of the thermoplastic elastomer composition while maintaining high-temperature toughness. Furthermore, by blending a copolymer (B1-1) having a glass transition temperature lower than a specific temperature and a copolymer (B2-2) having a glass transition temperature lower than a specific temperature with the polyamide resin (A1) at a specific ratio, the flexibility of the thermoplastic elastomer composition is enhanced while maintaining the high-temperature rigidity of the polyamide resin. Furthermore, by blending a specific amount of hydrogenated petroleum resin (C) with respect to a total of 100 parts by weight of the polyamide resin (A1), copolymer (B1-1), and copolymer (B2-2), the glass transition temperature of copolymer (B1-1) and / or copolymer (B2-2) is shifted toward a higher temperature, thereby improving the loss tangent of the thermoplastic elastomer composition at a temperature of 23°C at a frequency of 100 Hz. A high loss tangent of the thermoplastic elastomer composition results in a thermoplastic elastomer composition having excellent vibration damping properties.

[0107] The polyamide resin (A1) used in this embodiment is a polyamide resin having a melting point of 200° C. or higher as measured by DSC. The polyamide resin (A1) used in this embodiment is preferably the same as the polyamide resin (A1) described above.

[0108] The copolymer (B1-1) used in the present embodiment is a copolymer having a reactive functional group and comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof.

[0109] The reactive functional group in the copolymer (B1-1) is preferably the same as the reactive functional group described above for the copolymer (B1).

[0110] As the aromatic vinyl compound in the copolymer (B1-1), the same compounds as those described above for the copolymer (B1) are preferred.

[0111] The polymer block mainly composed of a conjugated diene compound and / or its hydrogenated product in the copolymer (B1-1) is preferably the same as the polymer block mainly composed of a conjugated diene compound and / or its hydrogenated product described above for the copolymer (B1).

[0112] The ratio of the polymer block primarily composed of an aromatic vinyl compound to the polymer block primarily composed of a conjugated diene compound constituting the copolymer (B1-1) is not particularly limited, but from the perspective of loss tangent, the content of the polymer block primarily composed of an aromatic vinyl compound in the copolymer (B1-1) is preferably 10 to 70% by weight. If the content of the polymer block primarily composed of an aromatic vinyl compound is 10% by weight or greater, sufficient mechanical properties are achieved, while if it is 70% by weight or less, a high loss tangent can be achieved.

[0113] The molecular weight of the copolymer (B1-1) is not particularly limited, but from the perspectives of molding processability, fluidity, rubber elasticity, etc., the weight average molecular weight measured by GPC is preferably 5,000 to 400,000, and more preferably 10,000 to 200,000. A weight average molecular weight of 5,000 or greater exhibits sufficient mechanical properties, while a weight average molecular weight of 400,000 or less results in excellent processability and fluidity of the molded article.

[0114] The amount of the reactive functional groups introduced into the copolymer (B1-1) is preferably 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and even more preferably 0.5 to 3 parts by weight, relative to 100 parts by weight of the copolymer (B1-1). By setting the amount of the reactive functional groups to 0.1 parts by weight or greater, the reactivity with the polyamide resin (A) can be improved. On the other hand, if the amount of the reactive functional groups exceeds 20 parts by weight, the reaction between the polyamide resin (A) and the copolymer (B1-1) may proceed excessively, resulting in a decrease in the high-temperature rigidity of the thermoplastic elastomer composition.

[0115] Copolymer (B2-2) used in this embodiment refers to a copolymer other than component (B1-1) that includes a polymer block primarily composed of an aromatic vinyl compound and a polymer block primarily composed of a conjugated diene compound and / or a hydrogenated product thereof. Specifically, it is a copolymer that includes a polymer block primarily composed of an aromatic vinyl compound and a polymer block primarily composed of a conjugated diene compound and / or a hydrogenated product thereof, and does not have any reactive functional groups.

[0116] As the aromatic vinyl compound in the copolymer (B2-2), the same compounds as those described above for the copolymer (B1) are preferred.

[0117] The polymer block mainly composed of a conjugated diene compound and / or its hydrogenated product in the copolymer (B2-2) is preferably the same as the polymer block mainly composed of a conjugated diene compound and / or its hydrogenated product described above for the copolymer (B1).

[0118] The block copolymer (B2-2) of this embodiment is not particularly limited in structure as long as it is composed of a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or their hydrogenated products. For example, linear, branched, or star-shaped structures may be selected.

[0119] The ratio of the polymer block mainly composed of an aromatic vinyl compound to the polymer block mainly composed of a conjugated diene compound in copolymer (B2-2) is not particularly limited, but from the perspective of loss tangent, the content of the polymer block mainly composed of an aromatic vinyl compound in copolymer (B2-2) is preferably 10 to 70% by weight. If the content of the polymer block mainly composed of an aromatic vinyl compound is 10% by weight or greater, sufficient mechanical properties are exhibited, while if it is 70% by weight or less, a high loss tangent can be achieved.

[0120] The molecular weight of the copolymer (B2-2) is not particularly limited, but is preferably 5,000 to 400,000, more preferably 10,000 to 200,000, as measured by GPC, in view of molding processability, fluidity, rubber elasticity, and the like. A weight-average molecular weight of 5,000 or greater exhibits sufficient mechanical properties, while a weight-average molecular weight of 400,000 or less provides excellent processability and fluidity of the molded article.

[0121] In addition, in this embodiment, the compound which corresponds to both the component (B1-1) and the component (B2-2) and has a reactive functional group is regarded as the component (B1-1).

[0122] The glass transition temperature of copolymers (B1-1) and (B2-2) can be determined by the following method. Samples kept in an absolute dry state were measured using a viscoelasticity measuring instrument (DMS6100, manufactured by Seiko Instruments Inc.) under a nitrogen atmosphere at a frequency of 100 Hz and a heating rate of 2°C / minute to determine the storage modulus and loss modulus. The loss tangent was calculated by dividing the loss modulus by the storage modulus. The peak position of the loss tangent obtained in this manner was taken as the glass transition temperature.

[0123] The glass transition temperature of the copolymer (B1-1) in this embodiment is -40°C or lower. If the glass transition temperature is higher than -40°C, the peak temperature of the loss tangent may shift excessively to the high temperature side due to the addition of the hydrogenated petroleum resin (C), and the loss tangent of the thermoplastic elastomer composition at a frequency of 100 Hz and a temperature of 23°C may decrease. The glass transition temperature of the copolymer (B1-1) is preferably -42°C or lower, more preferably -43°C or lower, and even more preferably -45°C or lower.

[0124] The lower limit of the glass transition temperature of the copolymer (B1-1) is not particularly limited, but is preferably -100°C or higher from the viewpoint of cost.

[0125] The glass transition temperature of the copolymer (B2-2) in this embodiment is -20°C or lower. If the glass transition temperature is higher than -20°C, the peak temperature of the loss tangent may shift excessively to the high temperature side due to the addition of the hydrogenated petroleum resin (C), and the loss tangent of the thermoplastic elastomer composition at a frequency of 100 Hz and a temperature of 23°C may decrease. The glass transition temperature of the copolymer (B2-2) is preferably -21°C or lower, more preferably -22°C or lower, and even more preferably -25°C or lower.

[0126] The lower limit of the glass transition temperature of the copolymer (B2-2) is not particularly limited, but is preferably -100°C or higher from the viewpoint of cost.

[0127] Examples of methods for adjusting the glass transition temperature of the copolymer (B1-1) and the copolymer (B2-2) to the above range include adjusting the structures and copolymerization ratios of the copolymer components of the copolymer (B1-1) and the copolymer (B2-2).

[0128] Regarding the blending amounts of the polyamide resin (A1), the copolymer (B1-1), and the copolymer (B2-2) contained in the thermoplastic elastomer composition of the present embodiment, the ratio (weight ratio) of the polyamide resin (A1) to the copolymer (B1-1) (A1):(B1-1) is 50:50 to 80:20, the ratio (weight ratio) of the copolymer (B1-1) to the copolymer (B2-2) (B1-1):(B2-2) is 90:10 to 25:75, and the ratio (weight ratio) of the polyamide resin (A1) to the total of the copolymer (B1-1) and the copolymer (B2-2) (A1):((B1-1) + (B2-2)) is 40:60 to 65:35. If the ratio of copolymer (B1-1) to (A1):(B1-1) is greater than 50:50, the reaction between the polyamide resin (A1) and the copolymer (B1-1) proceeds excessively, the high-temperature rigidity of the polyamide resin is not readily exhibited, and the high-temperature rigidity of the thermoplastic elastomer composition is low. On the other hand, if the ratio of copolymer (B1-1) to (A1):(B1-1) is less than 80:20, the compatibility between the polyamide resin (A1) and the copolymer (B2-2) decreases. The ratio of (A1):(B1-1) is 50:50 to 80:20, preferably 55:45 to 80:20, more preferably 58:42 to 80:20, and even more preferably 60:40 to 80:20. If the ratio of copolymer (B2-2) to (B1-1):(B2-2) is less than 90:10, the flexibility of the thermoplastic elastomer composition decreases. If the ratio of copolymer (B1-1) to (B1-1):(B2-2) is less than 25:75, the reactivity between the polyamide resin (A1) and the copolymer (B1-1) decreases, resulting in reduced high-temperature toughness. The ratio of (B1-1):(B2-2) is 90:10 to 25:75, preferably 90:10 to 28:72, more preferably 90:10 to 30:70, and even more preferably 90:10 to 35:65. Furthermore, if the ratio of ((B1-1) + (B2-2)) to (A1):((B1-1) + (B2-2)) is greater than 40:60, the high-temperature rigidity of the polyamide resin (A1) is less likely to be exhibited, resulting in reduced high-temperature rigidity of the thermoplastic elastomer composition. Furthermore, when the ratio of ((B1-1) + (B2-2)) is less than 65:35 (the ratio of (A1):((B1-1) + (B2-2)), the loss tangent of the thermoplastic elastomer composition at a frequency of 100 Hz and a temperature of 23°C when the hydrogenated petroleum resin (C) is blended decreases. The ratio of (A1):((B1-1) + (B2-2)) is 40:60 to 65:35, preferably 45:55 to 65:35, more preferably 50:50 to 65:35, and even more preferably 55:45 to 65:35.

[0129] The thermoplastic elastomer composition of this embodiment further contains a hydrogenated petroleum resin (C) in addition to the polyamide resin (A1), the copolymer (B1-1) and the copolymer (B2-2).

[0130] The hydrogenated petroleum resin (C) is preferably the same as the hydrogenated petroleum resin (C) described above.

[0131] The content of the hydrogenated petroleum resin (C) in the thermoplastic elastomer composition of this embodiment is 0.01 to 20 parts by weight relative to 100 parts by weight of the total of the polyamide resin (A1), copolymer (B1-1), and copolymer (B2-2). If the content is less than 0.01 parts by weight, the glass transition temperature of copolymer (B1-1) and copolymer (B2-2) cannot be shifted to the higher temperature side, and the loss tangent of the thermoplastic elastomer composition at a frequency of 100 Hz and a temperature of 23°C does not reach 0.10 or higher, resulting in poor vibration damping properties. On the other hand, if the content exceeds 20 parts by weight, it is not preferred because it causes surface stickiness due to bleed-out. The content of the hydrogenated petroleum resin is preferably 0.01 to 15 parts by weight, more preferably 0.1 to 15 parts by weight, and even more preferably 1.5 to 15 parts by weight.

[0132] The thermoplastic elastomer composition of the present invention has excellent spinnability.

[0133] The spinnability can be confirmed by the following method: The thermoplastic elastomer composition pellets are vacuum dried at 80°C for 15 hours. The vacuum dried pellets are then dried using a 1C (capillary rheometer) cylinder diameter 9.55mm, hole length 10.0mm, inner diameter 1.0mm. The thermoplastic elastomer composition was filled into the cylinder set to the test temperature of 280°C, compacted and held for 30 minutes to melt it, then discharged at an extrusion speed of 10mm / min and pulled at a pulling speed of 200m / min to confirm the spinnability.

[0134] In order to achieve excellent spinnability, the ratio (weight ratio) of the polyamide resin (A) and the thermoplastic elastomer (B) contained in the thermoplastic elastomer composition is preferably (A):(B) = 40:60 to 90:10. More preferably, the thermoplastic elastomer composition is any one of the thermoplastic elastomer composition of the first embodiment, the thermoplastic elastomer composition of the second embodiment, and the thermoplastic elastomer composition of the third embodiment.

[0135] The thermoplastic elastomer composition of the present invention is excellent in sheet moldability.

[0136] Sheet formability can be confirmed by the following method: Thermoplastic elastomer composition pellets are vacuum dried at 80°C for 15 hours. The vacuum-dried pellets are melted and kneaded in an extruder, and the resin is extruded from a die in a certain direction and fixed to a roll to form a sheet.

[0137] In order to achieve excellent sheet moldability, the ratio (weight ratio) of the polyamide resin (A) and the thermoplastic elastomer (B) contained in the thermoplastic elastomer composition is preferably (A):(B) = 40:60 to 90:10. More preferably, the thermoplastic elastomer composition is any one of the thermoplastic elastomer composition of the first embodiment, the thermoplastic elastomer composition of the second embodiment, and the thermoplastic elastomer composition of the third embodiment.

[0138] The thermoplastic elastomer composition of the present invention may contain, as needed, 0 to 100 parts by weight of other components other than the above components, relative to 100 parts by weight of the total of the polyamide resin (A) and the thermoplastic elastomer (B), within a range that does not impair its properties. Examples of such other components include fillers, copper compounds, potassium compounds, thermoplastic resins other than the above component (A), and various additives.

[0139] For example, by mixing fillers, the strength and dimensional stability of the molded product can be improved. The filler can be fibrous or non-fibrous, or a combination of fibrous and non-fibrous fillers can be used. Examples of fibrous fillers include glass fibers, ground glass fibers, carbon fibers, potassium titanate whiskers, zinc oxide whiskers, aluminum nitrate whiskers, aramid fibers, aluminum oxide fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, gypsum fibers, and metal fibers. Examples of non-fibrous fillers include silicates such as wollastonite, zeolite, sericite, kaolin, mica, pyrophyllite, bentonite, asbestos, and aluminum silicate; metal oxides such as aluminum oxide, magnesium oxide, zirconium oxide, titanium oxide, and iron oxide; metal carbonates such as calcium carbonate, magnesium carbonate, and dolomite; metal sulfates such as calcium sulfate and barium sulfate; metal hydroxides such as magnesium hydroxide, calcium hydroxide, and aluminum hydroxide; glass beads, ceramic beads, boron nitride, and silicon carbide. They can be hollow. In addition, from the viewpoint of obtaining more excellent mechanical properties, it is preferred to pre-treat these fibrous and / or non-fibrous fillers with a coupling agent. As coupling agents, for example, isocyanate compounds, organosilane compounds, organotitanate compounds, organoborane compounds, and epoxy compounds can be mentioned.

[0140] As the copper compound, for example, copper chloride, copper bromide, copper iodide, copper acetate, copper acetylacetonate, copper carbonate, copper fluoroborate, copper citrate, copper hydroxide, copper nitrate, copper sulfate, copper oxalate etc. can be enumerated. As the copper compound, two or more of these can also be contained. Among these copper compounds, preferably industrially available copper compounds, copper halide is suitable. As the copper halide, for example, copper iodide, cuprous bromide, cuprous bromide, cuprous chloride etc. can be enumerated. As the copper compound, copper iodide is more preferably used.

[0141] Examples of potassium compounds include potassium iodide, potassium bromide, potassium chloride, potassium fluoride, potassium acetate, potassium hydroxide, potassium carbonate, and potassium nitrate. Two or more of these compounds may also be included. Among these potassium compounds, potassium iodide is preferred. By including a potassium compound, the surface appearance, weather resistance, and mold corrosion resistance of the molded article can be improved.

[0142] Since the potassium compound suppresses the liberation and precipitation of copper, it is considered that the combined use of the copper compound and the potassium compound has the effect of promoting the reaction between the copper compound and the polyamide resin (A).

[0143] Examples of thermoplastic resins include polyamide resins other than the polyamide resin (A), polyester resins, polyphenylene sulfide resins, polyphenylene ether resins, polycarbonate resins, polylactic acid resins, polyacetal resins, polysulfone resins, tetrafluoroethylene resins, polyetherimide resins, polyamideimide resins, polyimide resins, polyethersulfone resins, polyetherketone resins, polysulfideetherketone resins, polystyrene resins, styrene-based resins such as ABS resin, and polyalkylene oxide resins. Two or more of these thermoplastic resins may be blended. When a thermoplastic resin other than the polyamide resin (A) is blended, its content is preferably 5 parts by weight or less per 100 parts by weight of the polyamide resin (A).

[0144] Examples of the various additives include anti-discoloring agents, antioxidants such as hindered phenols and hindered amines, mold release agents such as ethylene bisstearamide and higher fatty acid esters, plasticizers, heat stabilizers, lubricants, UV inhibitors, colorants, flame retardants, and foaming agents.

[0145] Next, the method for producing the thermoplastic elastomer composition of the present invention will be described. Examples of methods for producing the thermoplastic elastomer composition of the present invention include: a method of kneading the polyamide resin (A), the thermoplastic elastomer (B), and other components as needed; a method of mixing and kneading the polyamide resin (A) and a portion of the thermoplastic elastomer (B) and / or other components as needed through a side feeder during melt kneading. Kneading apparatuses such as Banbury mixers, rolls, and extruders can be used. When other components such as various additives are added to the thermoplastic elastomer composition of the present invention, they can be added at any stage. For example, when producing the thermoplastic elastomer composition of the present invention using a twin-screw extruder, methods include mixing the other components simultaneously with the mixing of the polyamide resin (A) and the thermoplastic elastomer (B); and methods of mixing the other components during the melt kneading of the polyamide resin (A) and the thermoplastic elastomer (B) using a side feeder or other methods.

[0146] The thermoplastic elastomer composition of the present invention can be molded by any method to obtain a molded article of any shape. Examples of molding methods include extrusion molding, injection molding, hollow molding, calendaring molding, compression molding, vacuum molding, foam molding, blow molding, and rotational molding. Examples of molded shapes include pellets, plates, fibers, tows, films or sheets, tubes, hollow bodies, and boxes.

[0147] The thermoplastic elastomer composition of the present invention can be foam-molded. Chemical foaming and physical foaming can be used as foam-molding methods. Examples of chemical foaming include methods in which a foaming agent is added to the thermoplastic elastomer composition during melt-kneading, followed by molding after melt-kneading; and methods in which a foaming agent is dry-blended with the thermoplastic elastomer composition of the present invention before molding, followed by molding. Examples of physical foaming include batch methods in which a thermoplastic elastomer composition molded in an autoclave is impregnated with a supercritical gas to cause foaming; and continuous methods in which a supercritical gas is impregnated with the thermoplastic elastomer composition during melt-kneading to cause foaming. Physical foaming is preferred from the perspectives of productivity and quality.

[0148] The supercritical gas used in physical foaming is not particularly limited as long as it can be dissolved in the thermoplastic elastomer composition and is inert. However, carbon dioxide or nitrogen is preferred from the perspectives of safety and cost. The supercritical gas is preferably used in an amount of 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight, per 100 parts by weight of the thermoplastic elastomer composition.

[0149] Foam molding can produce, for example, foam injection molded products and foam sheets. These molded products and sheets have high loss tangents and are therefore suitable for use as vibration damping members, sound absorbing members, and the like.

[0150] The molded article of the present invention has excellent vibration damping properties, high-temperature rigidity, and blocking resistance, and therefore can be widely used in, for example, automotive applications and electrical / electronic applications. Among them, it can be particularly suitably used as a vibration damping member or a sound absorbing member.

[0151] Example

[0152] The effects of the present invention are further specifically described below with reference to the following examples. It should be noted that the present invention is not limited to the following examples. Evaluations in the examples and comparative examples were performed using the following methods.

[0153] (1) Melting point of polyamide resin

[0154] The melting points of the polyamide resins used in each example and comparative example were determined by DSC. First, a differential scanning calorimeter (DSC-7, manufactured by PerkinElmer) was used for two-point calibration (indium and lead) and baseline correction. 8-10 mg of polyamide resin was weighed and heated at a rate of 20°C / minute. The melting endothermic peak temperature observed during the heating process was defined as the melting point.

[0155] (2) Glass transition temperatures of copolymer (B1-1), copolymer (B2-1), and copolymer (B2-2)

[0156] The glass transition temperatures of copolymers (B1-1), (B2-1), and (B2-2) used in each of the Examples and Comparative Examples were determined by viscoelasticity measurement. First, using the oven-dried copolymers (B1-1), (B2-1), and (B2-2), an 80 mm × 80 mm × 1 mm² flat plate was prepared in the same manner as in the Examples described below. A thin rectangle measuring 40 mm × 8 mm × 1 mm² was cut from the flat plate to serve as a measurement sample. The sample was measured using a viscoelasticity measuring instrument (Seiko Instruments Inc., DMS6100) under a nitrogen atmosphere at a frequency of 100 Hz and a heating rate of 2°C / minute to determine the storage modulus and loss modulus. The loss tangent was calculated by dividing the loss modulus by the storage modulus. The peak temperature of the loss tangent was defined as the glass transition temperature.

[0157] (3) High temperature rigidity: melting point

[0158] High-temperature rigidity was evaluated by melting point. The melting point of the thermoplastic elastomer composition pellets obtained in each Example and Comparative Example was determined using DSC measurement. First, a differential scanning calorimeter (DSC-7, manufactured by PerkinElmer) was used for two-point calibration (indium and lead) and baseline correction. 8-10 mg of the thermoplastic elastomer composition was weighed and heated at a rate of 20°C / minute. The melting endothermic peak temperature observed during the heating process was defined as the melting point. A thermoplastic elastomer composition with a melting point of 200°C or higher can impart high-temperature rigidity to molded articles, maintaining their shape.

[0159] (4) Vibration damping: loss tangent (tanδ)

[0160] Thin rectangles measuring 40 mm x 8 mm x 1 mm were cut from 80 mm x 80 mm x 1 mm flat plates of the thermoplastic elastomer compositions obtained in each of the Examples and Comparative Examples. The cut rectangles were used as measurement samples and measured using a viscoelasticity measuring instrument (Seiko Instruments Inc., DMS6100) under a nitrogen atmosphere at a frequency of 100 Hz and a heating rate of 2°C / minute to determine the storage modulus and loss modulus. The loss tangent (tan δ) at 23°C was calculated by dividing the loss modulus at 23°C by the storage modulus.

[0161] (5) Productivity: Adhesion

[0162] The pellets obtained in each of the Examples and Comparative Examples were vacuum-dried at 80° C. for 15 hours. The adhesion (blocking) of the pellets at this time was confirmed.

[0163] (6) Spinning properties: high-speed traction

[0164] The thermoplastic elastomer composition pellets obtained in each example and comparative example were vacuum dried at 80°C for 15 hours. 1C (capillary rheometer) (cylinder diameter 9.55 mm, hole length 10.0 mm, inner diameter 1.0 mm): The thermoplastic elastomer composition is filled into the cylinder set to a test temperature of 280°C, compacted and held for 30 minutes to melt, then discharged at an extrusion speed of 10 mm / min. The thermoplastic elastomer composition is then pulled into a thread at a pulling speed of 200 m / min. At this time, the thermoplastic elastomer composition is judged as good (good spinnability) if it can be pulled, and judged as poor (poor spinnability) if it cannot be pulled.

[0165] (7) Sheet formability

[0166] Thermoplastic elastomer composition pellets obtained in each of the Examples and Comparative Examples were vacuum-dried at 80°C for 15 hours. The vacuum-dried thermoplastic elastomer composition pellets were melted and kneaded in an extruder. The resin was extruded from a die in a fixed direction and fixed to a roller to form a sheet. Sheet formation was evaluated as good (good sheet formability), while failure to form a sheet was evaluated as poor (poor sheet formability).

[0167] The raw materials and abbreviations used in each of the Examples and Comparative Examples are shown below.

[0168] [SEBS-3]

[0169] In a nitrogen-purged reaction vessel, 700 parts by weight of cyclohexane, 7.5 parts by weight of styrene, and 0.07 parts by weight of sec-butyllithium were added to 100 parts by weight of all monomers. The first stage polymerization was carried out at a polymerization start temperature of 50°C. After the reaction was completed, the temperature was set to 70°C, and 85 parts by weight of 1,3-butadiene was added to carry out adiabatic polymerization in the second stage. After 30 minutes, 7.5 parts by weight of styrene was added to carry out the third stage polymerization. After the reaction, methanol was added to terminate the polymerization. The total amount of all monomers herein refers to the total amount of all monomers added in each stage of the polymerization process. After the reaction, the reaction solution was returned to room temperature and pressure, removed from the reaction vessel, stirred, poured into water, and the solvent was removed by steam distillation to obtain conjugated diene polymer 1. Cyclopentadienyltitanium dichloride was added to the resulting conjugated diene polymer 1 to achieve a titanium atom content of 50 ppm relative to the weight of the polymer. Furthermore, triethylaluminum was added in an amount 3 times the molar amount of the titanium. A hydrogenation reaction was carried out at a hydrogen pressure of 1 MPa and a temperature of 75°C for one hour to obtain SEBS-3. The glass transition temperature of the obtained SEBS-3 was measured and found to be -15°C. (Equivalent to a copolymer of copolymer (B2) and copolymer (B2-1))

[0170] [SEBS-g-MAH-2]

[0171] 1.4 parts by weight of maleic anhydride was dry-mixed with 100 parts by weight of the obtained SEBS-3. 25B (manufactured by NOF Corporation, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane) 0.15 parts by weight, 0.1 part by weight of P168 (tris(2,4-di-tert-butylphenyl)phosphite, manufactured by BASF) was supplied to a twin-screw extruder (TEX30XSSST manufactured by JSW Corporation) (L / D = 45.5 (where L is the length from the raw material supply port to the discharge port, and D is the screw diameter) set at a cylinder temperature of 230°C) and melt-kneaded to graft-add maleic anhydride to SEBS-3, thereby obtaining SEBS-g-MAH-2.

[0172] The resulting SEBS-g-MAH-2 was extracted and purified with acetone. After drying, the amount of maleic anhydride added was determined by titration with sodium methoxide, resulting in 1.3 wt% maleic anhydride. The glass transition temperature of the resulting SEBS-g-MAH-2 was measured and found to be -15°C. (Copolymer equivalent to copolymer (B1))

[0173] PA6: Polyamide 6 resin "Toray Industries, Inc." "(Registered trademark)" (melting point 224°C, resin concentration 0.01g / ml 98% concentrated sulfuric acid solution at 25°C relative viscosity 2.70) (polyamide equivalent to polyamide resin (A1))

[0174] PA12: Polyamide 12 resin Daimid Co., Ltd. (registered trademark) (melting point 178°C) (polyamide that does not qualify as polyamide resin (A1))

[0175] SEBS-g-MAH-1: Maleic anhydride modified styrene-ethylene / butylene-styrene block copolymer (Co., Ltd.) "(Registered trademark) FG1924" (styrene content 13.9%, acid modification amount 1.0wt%, Tg = -55°C) (copolymer equivalent to copolymer (B1) and copolymer (B1-1))

[0176] SEBS-g-MAH-2: Maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer (styrene content 15%, acid modification amount 1.3 wt%, Tg = -15°C) produced in [SEBS-g-MAH-2] (copolymer equivalent to copolymer (B1))

[0177] SEBS-1: Styrene-ethylene / butylene-styrene block copolymer "SOE" (registered trademark) S1606 manufactured by Asahi Kasei Corporation" (Tg = -10°C) (equivalent to copolymers of copolymers (B2) and (B2-1))

[0178] SEBS-2: Styrene-ethylene / butylene-styrene block copolymer "Made by Asahi Kasei Corporation" "(Registered trademark) H1052" (Tg = -44°C) (equivalent to copolymer (B2) and copolymer (B2-2))

[0179] SEBS-3: Styrene-ethylene / butylene-styrene block copolymer (styrene content 15%, Tg = -15°C) produced in [SEBS-3] (equivalent to copolymer (B2) and copolymer (B2-1))

[0180] SEBS-4: Styrene-ethylene / butylene-styrene block copolymer (Co., Ltd.) "(Registered trademark) G1645VO" (styrene content 13%, Tg = -25°C) (copolymer equivalent to copolymer (B2) and copolymer (B2-2))

[0181] SIS: Styrene-isoprene-styrene block copolymer (Co., Ltd.) "(Registered trademark) D1161" (styrene content 15%, Tg = -50°C) (copolymer equivalent to copolymer (B2) and copolymer (B2-2))

[0182] SBS: Styrene-butadiene-styrene copolymer (Co., Ltd.) "(Registered trademark) D1102" (styrene content 29%, Tg = -90°C) (copolymer equivalent to copolymer (B2) and copolymer (B2-2))

[0183] SEPS: Styrene-ethylene / propylene-styrene block copolymer" (Co., Ltd.) "(Registered trademark) G1730" (styrene content 20%, Tg = -45°C) (copolymer equivalent to copolymer (B2) and copolymer (B2-2))

[0184] Hydrogenated petroleum resin: C9 series hydrogenated petroleum resin " " "P-140" (Arakawa Chemical Industries, Ltd.) (resin equivalent to hydrogenated petroleum resin (C)).

[0185] [Examples 1 to 9, Comparative Examples 1 to 6]

[0186] The raw materials listed in Tables 1 and 2 were supplied to a twin-screw extruder (TEX30XSSST manufactured by JSW Corporation) (L / D = 45.5 (where L is the length from the raw material supply port to the discharge port, and D is the screw diameter) with the barrel temperature set at 250°C and the screw configuration provided with two kneading zones, and the screw speed was set at 250 rpm, and melt-kneaded. The strands discharged from the die of the twin-screw extruder were quenched for 15 seconds in a cooling bath filled with water adjusted to 10°C to stabilize the structure, and then pelletized using a strand cutter. Pellets of a thermoplastic elastomer composition were obtained. The resulting pellets were molded into 80 mm x 80 mm x 1 mm flat plates using a Sumitomo Heavy Industries, Ltd. injection molding machine (SE-75DUZ-C250) under the following molding conditions: a mold temperature of 80°C, an injection speed of 40 mm / second, and a cooling time of 60 seconds. The injection molding machine temperature was set at 240°C-245°C-250°C-250°C from the bottom of the hopper toward the tip. The pellets and molded articles obtained were evaluated using the aforementioned methods and the results are shown in Tables 1 and 2.

[0187] The thermoplastic elastomer compositions of Examples 1 to 9 are the thermoplastic elastomer compositions of the first embodiment described above, and have a loss tangent of 0.10 or greater at a frequency of 100 Hz and a temperature of 23°C, and a melting point of 200°C or greater as measured by differential scanning calorimetry (DSC). These compositions are found to exhibit excellent vibration damping properties, high-temperature rigidity, and blocking resistance, and further exhibit excellent moldability such as spinnability and sheet moldability.

[0188]

[0189]

[0190] [Examples 10 to 14, Comparative Examples 7 to 11]

[0191] The raw materials listed in Tables 3 and 4 were supplied to a twin-screw extruder (TEX30XSSST manufactured by JSW Corporation) (L / D = 45.5 (where L is the length from the raw material supply port to the discharge port, and D is the screw diameter) with the barrel temperature set at 250°C and the screw configuration provided with two kneading zones, and the screw speed set at 250 rpm, for melt kneading. The strands discharged from the die of the twin-screw extruder were quenched for 15 seconds in a cooling bath filled with water adjusted to 10°C to stabilize the structure, and then pelletized using a strand cutter to obtain The resulting pellets of the thermoplastic elastomer composition were molded into 80 mm × 80 mm × 1 mm² flat plates using a Sumitomo Heavy Industries, Ltd. injection molding machine (SE-75DUZ-C250) under the following molding conditions: a mold temperature of 80°C, an injection speed of 40 mm / second, and a cooling time of 60 seconds. The injection molding machine temperature was set at 240°C–245°C–250°C–250°C from the bottom of the hopper toward the tip. The pellets and molded articles obtained were evaluated using the aforementioned methods and the results are shown in Tables 3 and 4.

[0192] The thermoplastic elastomer compositions of Examples 10 to 14 are the thermoplastic elastomer compositions of the second embodiment described above, and have a loss tangent of 0.10 or greater at a frequency of 100 Hz and a temperature of 23°C, and a melting point of 200°C or greater as measured by differential scanning calorimetry (DSC). These compositions are found to exhibit excellent vibration damping properties, high-temperature rigidity, and blocking resistance, and further exhibit excellent moldability such as spinnability and sheet moldability.

[0193]

[0194]

[0195] [Examples 15 to 19, Comparative Examples 12 to 16]

[0196] The raw materials listed in Tables 5 and 6 were supplied to a twin-screw extruder (TEX30XSSST manufactured by JSW Corporation) (L / D = 45.5 (where L is the length from the raw material supply port to the discharge port, and D is the screw diameter) with the barrel temperature set at 250°C and the screw configuration provided with two kneading zones, and the screw speed set at 250 rpm, for melt kneading. The strands discharged from the die of the twin-screw extruder were quenched for 15 seconds in a cooling bath filled with water adjusted to 10°C to stabilize the structure, and then pelletized using a strand cutter to obtain The resulting pellets of the thermoplastic elastomer composition were molded into 80 mm × 80 mm × 1 mm² flat plates using a Sumitomo Heavy Industries, Ltd. injection molding machine (SE-75DUZ-C250) under the following molding conditions: a mold temperature of 80°C, an injection speed of 40 mm / second, and a cooling time of 60 seconds. The injection molding machine temperature was set at 240°C–245°C–250°C–250°C from the bottom of the hopper toward the tip. The pellets and molded articles obtained were evaluated using the aforementioned methods and the results are shown in Tables 5 and 6.

[0197] The thermoplastic elastomer compositions of Examples 15 to 19 are the thermoplastic elastomer compositions of the third embodiment described above, and have a loss tangent of 0.10 or greater at a frequency of 100 Hz and a temperature of 23°C, and a melting point of 200°C or greater as measured by differential scanning calorimetry (DSC). These compositions are found to exhibit excellent vibration damping properties, high-temperature rigidity, and blocking resistance, and further exhibit excellent moldability such as spinnability and sheet moldability.

[0198]

[0199]

[0200] Industrial applicability

[0201] Molded articles formed from the thermoplastic elastomer composition of the present invention exhibit excellent vibration damping properties, high-temperature rigidity, and blocking resistance, and can be easily manufactured. Leveraging these properties, the thermoplastic elastomer composition of the present invention can be widely used in various molded articles, such as sound absorbing members and vibration damping members, and is particularly suitable for automotive, electrical and electronic, and consumer applications.

Claims

1. A thermoplastic elastomer composition comprising a polyamide resin (A) and a thermoplastic elastomer (B), wherein the thermoplastic elastomer composition has a loss tangent of 0.10 or greater at a frequency of 100 Hz and a temperature of 23° C., and a melting point of 200° C. or greater as measured by differential scanning calorimetry (DSC). 2 . The thermoplastic elastomer composition according to claim 1 , wherein the weight ratio of the polyamide resin A to the thermoplastic elastomer B contained in the thermoplastic elastomer composition is A:B=40:60 to 90:

10. 3 . The thermoplastic elastomer composition according to claim 1 , wherein the polyamide resin A is a polyamide resin A1 having a melting point of 200° C. or higher as measured by differential scanning calorimetry (DSC).

4. The thermoplastic elastomer composition according to claim 1, wherein the thermoplastic elastomer B is at least one selected from the group consisting of copolymer B1 and copolymer B2, wherein the copolymer B1 is a copolymer having a reactive functional group and comprising a polymer block mainly composed of an aromatic vinyl compound, a polymer block mainly composed of a conjugated diene compound, and / or a hydrogenated product thereof; and the copolymer B2 is a copolymer other than the component B1 and comprising a polymer block mainly composed of an aromatic vinyl compound, a polymer block mainly composed of a conjugated diene compound, and / or a hydrogenated product thereof. 5 . The thermoplastic elastomer composition according to claim 1 , comprising a polyamide resin A1, a copolymer B1, and a copolymer B2-1. The melting point of the polyamide resin A1 measured by differential scanning calorimetry (DSC) is above 200°C. The copolymer B1 is a copolymer having reactive functional groups and comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof. The copolymer B2-1 is a copolymer other than component B1, comprising a polymer block mainly composed of an aromatic vinyl compound, a polymer block mainly composed of a conjugated diene compound, and / or a hydrogenated product thereof, and has a glass transition temperature higher than -20°C. The weight ratio of the polyamide resin A1, copolymer B1, and copolymer B2-1 contained in the thermoplastic elastomer composition satisfies the following relationships: A1:B1=50:50 to 80:20, B1:(B2-1)=90:10 to 25:75, and A1:(B1+(B2-1))=40:60 to 70:

30. The thermoplastic elastomer composition according to claim 5 , further comprising a hydrogenated petroleum resin C, wherein the content of the hydrogenated petroleum resin C is 0.01 to 20 parts by weight based on 100 parts by weight of the total of the polyamide resin A1, copolymer B1, and copolymer B2-1.

7. The thermoplastic elastomer composition according to claim 1, wherein the thermoplastic elastomer composition comprises a polyamide resin A1, a copolymer B1 and a hydrogenated petroleum resin C. The melting point of the polyamide resin A1 measured by differential scanning calorimetry (DSC) is above 200°C. The copolymer B1 is a copolymer having reactive functional groups and comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof. The thermoplastic elastomer composition contains polyamide resin A1 and copolymer B1 at a weight ratio of A1:B1=50:50 to 90:10, and the content of hydrogenated petroleum resin C is 0.01 to 20 parts by weight based on 100 parts by weight of the total of the polyamide resin A1 and copolymer B1.

8. The thermoplastic elastomer composition according to claim 1, wherein the thermoplastic elastomer composition comprises a polyamide resin A1, a copolymer B1-1, a copolymer B2-2 and a hydrogenated petroleum resin C. The melting point of the polyamide resin A1 measured by differential scanning calorimetry (DSC) is above 200°C. The copolymer B1-1 is a copolymer having a reactive functional group and a glass transition temperature of -40°C or lower, comprising a polymer block mainly composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound and / or a hydrogenated product thereof. The copolymer B2-2 is a copolymer other than the component B1-1, comprising a polymer block mainly composed of an aromatic vinyl compound, a polymer block mainly composed of a conjugated diene compound, and / or a hydrogenated product thereof, and has a glass transition temperature of -20°C or lower. The weight ratio of the polyamide resin A1, the copolymer B1-1, and the copolymer B2-2 satisfies the following relationship: A1:(B1-1)=50:50 to 80:20, (B1-1):(B2-2)=90:10 to 25:75, and A1:((B1-1)+(B2-2))=40:60 to 65:

35. Furthermore, the content of the hydrogenated petroleum resin C is 0.01 to 20 parts by weight relative to 100 parts by weight of the total of the polyamide resin A1, the copolymer B1-1, and the copolymer B2-2.

9. The thermoplastic elastomer composition according to any one of claims 4 to 8, wherein the polymer block mainly composed of a conjugated diene compound and / or its hydrogenated product is a polymer block derived from at least one selected from the group consisting of isoprene, butadiene, ethylene / butylene, and ethylene / propylene.

10. A molded article made from the thermoplastic elastomer composition according to claim 1. The molded article according to claim 10 , which is a sound absorbing member.

12. The molded article according to claim 10, which is a vibration damping member.

13. The molded article according to claim 10, which is a molded article selected from the group consisting of injection molded articles, fibers, sheets, foamed injection molded articles, and foamed sheets.

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