Thermoplastic elastomer composition and molded article

Abstract

To provide a thermoplastic elastomer composition that enables manufacture of a molded article having superior vibration damping and excellent appearance.SOLUTION: A thermoplastic elastomer composition contains, within specified ranges, a polymer component (A), a crystalline propylene-based polymer (B), a vibration-damping material component (C1), a vibration-damping material component (C2), and a softener (D), wherein the polymer component (A) includes a crosslinked body in which at least part of an ethylene-C3 or higher α-olefin-non-conjugated polyene copolymer (A1) is crosslinked with a phenolic resin-based crosslinking agent (E), the tanδ peak temperature of the vibration-damping material component (C1) is less than 10°C, the tanδ peak temperature of the vibration-damping material component (C2) is 10°C or more, the composition has a tanδ peak within the range of -5°C to 10°C, and the tanδ value in the range of -5°C to 10°C is 0.2 or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a thermoplastic elastomer composition and a molded article. [Background technology]

[0002] Olefin-based thermoplastic elastomer compositions obtained by heat-treating a composition of an ethylene-α-olefin-non-conjugated polyene copolymer and a crystalline olefin polymer are lightweight and easily recyclable. Therefore, these thermoplastic elastomer compositions are used as energy-saving or resource-saving elastomers. These thermoplastic elastomer compositions are widely used, particularly as a replacement for vulcanized rubber, in fields such as automobile parts, industrial machinery parts, home appliance parts, electrical and electronic parts, and building materials (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-36143 Summary of the Invention [Problem to be solved by the invention]

[0004] In fields such as automotive parts, vibration-damping properties are required to suppress noise generated when an automobile is running. However, it has tended to be difficult to produce molded articles having both excellent vibration-damping properties and excellent appearance using conventional thermoplastic elastomer compositions. An object of the present disclosure is to provide a thermoplastic elastomer composition that can be used to produce molded articles having both excellent vibration-damping properties and excellent appearance. [Means for solving the problem]

[0005] The thermoplastic elastomer composition of the present disclosure contains a polymer component (A), a crystalline propylene-based polymer (B), a vibration-damping material component (C1), a vibration-damping material component (C2), and a softener (D), The polymer component (A) contains a crosslinked product in which at least a portion of an ethylene-α-olefin having 3 or more carbon atoms-non-conjugated polyene copolymer (A1) is crosslinked with a phenolic resin-based crosslinking agent (E), The peak temperature of tan δ of the vibration-damping material component (C1) obtained by dynamic viscoelasticity measurement is less than 10°C, and the peak temperature of tan δ of the vibration-damping material component (C2) obtained by dynamic viscoelasticity measurement is 10°C or higher, the composition has a peak of tan δ obtained by dynamic viscoelasticity measurement in the range of −5° C. to 10° C., and the value of tan δ in the range of −5° C. to 10° C. is 0.2 or more; In a total of 100% by mass of the polymer component (A), the crystalline propylene polymer (B), the vibration-damping material component (C1), the vibration-damping material component (C2), and the softener (D), the content of the polymer component (A) is 15 to 40% by mass, the content of the crystalline propylene polymer (B) is 10 to 55% by mass, the total content of the vibration-damping material component (C1) and the vibration-damping material component (C2) is 10 to 25% by mass, and the content of the softener (D) is 10 to 45% by mass. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to provide a thermoplastic elastomer composition that can be used to produce a molded article that has excellent vibration damping properties and excellent appearance, particularly a molded article that has excellent vibration damping properties over a wide temperature range and excellent appearance. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present disclosure will be described in detail. Each of the components described in this specification can be used singly or in combination of two or more. In this specification, the term "polymer" may be used without any particular distinction between homopolymers and copolymers. That is, the term "polymer" is used to mean both homopolymers and copolymers.

[0008] In this specification, when the numerical range is n1 to n2, if n1 < n2, it means n1 or more and n2 or less, and if n1 > n2, it means n2 or more and n1 or less. In this specification, when a plurality of lower limit values and upper limit values are described for the description of an element, a numerical range formed by combining a value arbitrarily selected from the described lower limit values and a value arbitrarily selected from the described upper limit values is also regarded as being described.

[0009] [Thermoplastic elastomer composition] The thermoplastic elastomer composition of the present disclosure (hereinafter, also simply referred to as "the composition of the present disclosure") will be described. The composition of the present disclosure is a polymer component (A), a crystalline propylene-based polymer (B), a vibration damping component (C1), a vibration damping component (C2), a softening agent (D), and contains

[0010] [Polymer component (A)] The composition of the present disclosure contains a polymer component (A). The polymer component (A) includes a crosslinked body in which at least a part of an ethylene·α-olefin having 3 or more carbon atoms·non-conjugated polyene copolymer (A1) (hereinafter, also simply referred to as "copolymer (A1)") is crosslinked by a phenolic resin-based crosslinking agent (E). Therefore, the molded body obtained from the above composition tends to be excellent in rubber elasticity, oil resistance, and hardness.

[0011] The above crosslinked body contained in the polymer component (A) includes, for example, a polymer part derived from the copolymer (A1) and a crosslinked part derived from the phenolic resin-based crosslinking agent (E) that crosslinks the polymer part. The polymer component (A) may include a copolymer (A1) that is not crosslinked by the phenolic resin-based crosslinking agent (E).

[0012] At least a portion of the copolymer (A1) is crosslinked with the phenolic resin-based crosslinking agent (E) in the composition. The timing of crosslinking of the copolymer (A1) is not particularly limited. For example, before mixing the copolymer (A1) with other components such as the crystalline propylene-based polymer (B), at least a portion of the copolymer (A1) may be (dynamically) crosslinked with the crosslinking agent (E). For example, after or while mixing the copolymer (A1) with other components such as the crystalline propylene-based polymer (B), at least a portion of the copolymer (A1) may be (dynamically) crosslinked with the crosslinking agent (E). A high degree of crosslinking of the copolymer (A1) tends to improve the rubber elasticity, oil resistance, and hardness of a molded article obtained from the composition.

[0013] The copolymer (A1) has structural units derived from ethylene, structural units derived from an α-olefin having 3 or more carbon atoms, and structural units derived from a non-conjugated polyene.

[0014] Copolymer (A1) has structural units derived from an α-olefin having 3 or more carbon atoms. Examples of α-olefins having 3 or more carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene. As the α-olefin, α-olefins having 3 to 20 carbon atoms are preferred, with propylene and 1-butene being more preferred, and propylene being particularly preferred, from the viewpoints of relatively low raw material costs, the ability to obtain copolymer (A1) with excellent mechanical properties, and the ability to mold the composition to obtain molded articles with excellent rubber elasticity. Copolymer (A1) is preferably an ethylene-propylene-non-conjugated polyene copolymer or an ethylene-1-butene-non-conjugated polyene copolymer, with ethylene-propylene-non-conjugated polyene copolymer being particularly preferred.

[0015] In producing the copolymer (A1), one or more α-olefins having 3 or more carbon atoms may be used. The copolymer (A1) has at least one structural unit derived from an α-olefin having 3 or more carbon atoms, and may have two or more structural units derived from an α-olefin having 3 or more carbon atoms.

[0016] The ratio (by mass) of the content of structural units derived from ethylene to the content of structural units derived from α-olefins having 3 or more carbon atoms in copolymer (A1) is hereinafter also referred to as the "ethylene / α-olefin ratio." The ethylene / α-olefin ratio is preferably 40 / 60 to 90 / 10, more preferably 45 / 55 to 80 / 20, even more preferably 50 / 50 to 75 / 25, still more preferably 55 / 45 to 70 / 30, and particularly preferably 55 / 45 to 68 / 32, since a thermoplastic elastomer composition having excellent mechanical strength can be obtained.

[0017] The content of each structural unit, such as the content of structural units derived from ethylene, the content of structural units derived from α-olefins having 3 or more carbon atoms, and the content of structural units derived from non-conjugated polyenes, is 13 It is calculated from the C-NMR spectrum.

[0018] The copolymer (A1) has structural units derived from non-conjugated polyenes. Examples of non-conjugated polyenes include cyclic non-conjugated dienes, linear non-conjugated dienes, and non-conjugated trienes. Examples of cyclic non-conjugated dienes include 5-ethylidene-2-norbornene, cyclohexadiene, dicyclopentadiene, 5-vinyl-2-norbornene, norbornadiene, and methyltetrahydroindene. Examples of linear non-conjugated dienes include 1,4-hexadiene, 1,6-octadiene, and 7-methyl-1,6-octadiene. Examples of non-conjugated trienes include 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,5-norbornadiene, 1,3,7-octatriene, 1,4,9-decatriene, 4,8-dimethyl-1,4,8-decatriene, 4-ethylidene-8-methyl-1,7-nonadiene, 4-ethylidene-1,7-undecadiene, and 8-methyl-4-ethylidene-1,7-nonadiene.

[0019] Among non-conjugated polyenes, from the viewpoint of crosslinkability, linear non-conjugated dienes such as 1,4-hexadiene, and cyclic non-conjugated dienes such as 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene are preferred, cyclic non-conjugated dienes are more preferred, and 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene are even more preferred.

[0020] As the copolymer (A1), from the viewpoint of excellent oil resistance and moldability, an ethylene-propylene-non-conjugated diene copolymer is preferred, and an ethylene-propylene-5-ethylidene-2-norbornene copolymer and an ethylene-propylene-5-vinyl-2-norbornene copolymer are more preferred.

[0021] In producing the copolymer (A1), one type of non-conjugated polyene may be used, or two or more types may be used. The copolymer (A1) has at least one type of structural unit derived from a non-conjugated polyene, and may have two or more types.

[0022] The content of the non-conjugated polyene-derived structural units in the copolymer (A1) is preferably 0.1 to 10 mass%, more preferably 1.0 to 8.0 mass%, even more preferably 2.0 to 7.0 mass%, and particularly preferably 3.0 to 6.0 mass%, based on 100 mass% of the total content of ethylene-derived structural units, structural units derived from α-olefins having 3 or more carbon atoms, and structural units derived from non-conjugated polyenes. Such copolymers tend to have excellent crosslinkability and flexibility. The above-mentioned compositions containing crosslinked products of such copolymers tend to be capable of forming molded articles having excellent rubber elasticity and oil resistance.

[0023] In copolymer (A1), the total content of ethylene-derived structural units, structural units derived from α-olefins having 3 or more carbon atoms, and structural units derived from non-conjugated polyenes, relative to the total amount of structural units derived from polymerizable monomers (100 mol %), is preferably 70 mol % or more, more preferably 80 mol % or more, even more preferably 90 mol % or more, still more preferably 95 mol % or more, and particularly preferably 98 mol % or more, from the viewpoint of obtaining a thermoplastic elastomer composition having good mechanical properties.

[0024] The ethylene may be derived from biomass. The α-olefin having 3 or more carbon atoms may be derived from biomass. The non-conjugated polyene may be derived from biomass.

[0025] The intrinsic viscosity [η] of the copolymer (A1) is preferably 1 to 7 dL / g, more preferably 2 to 6 dL / g, and even more preferably 3 to 5 dL / g. The composition containing such a crosslinked copolymer tends to form a molded article having excellent hardness and oil resistance. The intrinsic viscosity [η] is measured in decalin at 135°C.

[0026] Copolymer (A1) may be synthesized by a conventionally known method of copolymerizing ethylene, an α-olefin having 3 or more carbon atoms, and a non-conjugated polyene. Copolymer (A1) can be obtained by various known production methods, for example, by a conventionally known production method using a metallocene catalyst containing a metallocene compound as one of the catalyst components. Examples of metallocene catalysts and production methods using such catalysts include those described in WO 2015 / 122415 (particularly paragraphs

[0249] to

[0320] ). Copolymer (A1) may be a commercially available product. Copolymer (A1) constituting polymer component (A) may be one type or two or more types.

[0027] In the composition of the present disclosure, the content of polymer component (A) is 15 to 40 mass%, preferably 20 to 35 mass%, and more preferably 25 to 30 mass%, based on 100 mass% of the total content of polymer component (A), crystalline propylene polymer (B), vibration-damping material component (C1), vibration-damping material component (C2), and softener (D). Such a composition has excellent moldability and can form a molded article that is excellent in rubber elasticity, oil resistance, and hardness.

[0028] In the composition of the present disclosure, the total content of the polymer component (A), the crystalline propylene-based polymer (B), the vibration-damping component (C1), the vibration-damping component (C2), and the softener (D) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more, based on 100% by mass of the composition.

[0029] <Crystalline propylene polymer (B)> The composition of the present disclosure contains a crystalline propylene polymer (B). The "crystalline" propylene polymer refers to a propylene polymer that exhibits a melting point (Tm) when measured using a differential scanning calorimeter (DSC) under the measurement conditions described in the Examples section.

[0030] The crystalline propylene polymer (B) may be a propylene homopolymer or a copolymer of propylene and a comonomer other than propylene. The comonomer may be any monomer copolymerizable with propylene. Preferred comonomers are ethylene and α-olefins having 4 to 12 carbon atoms. Examples of comonomers include ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene. Of these, ethylene, 1-butene, and 1-octene are preferred. One or more types of comonomers may be used.

[0031] As the propylene, biomass-derived propylene may be used. As the comonomer, a comonomer derived from biomass may be used.

[0032] The case where the crystalline propylene polymer (B) is a copolymer will be described below. The content of propylene-derived structural units in the total amount of structural units constituting the copolymer is preferably 70% by mass or more, more preferably 80% by mass or more, since the oil resistance and mechanical strength of the composition are likely to be good.

[0033] The steric structure of the crystalline propylene polymer (B) is not particularly limited. For example, the steric structure consisting of propylene-derived structural units may be an isotactic structure, a syndiotactic structure, or an atactic structure.

[0034] The copolymer may be any of a random type, a block type, or a graft type, and specific examples of the copolymer include a propylene-ethylene block copolymer, a propylene-ethylene random copolymer, and a propylene-ethylene-1-butene random copolymer.

[0035] The crystalline propylene polymer (B) is preferably at least one selected from propylene homopolymers and block copolymers, since this tends to improve the oil resistance and hardness of the composition.

[0036] The melting point of the crystalline propylene polymer (B) is preferably 50 to 170°C, more preferably 70 to 167°C, even more preferably 100 to 167°C, still more preferably 130 to 167°C, and particularly preferably 150 to 167°C. The melting point is measured in accordance with JIS K7121 (2012), and details of the measurement conditions are described in the Examples section. A composition containing a polymer (B) having a melting point within the above range has excellent heat resistance.

[0037] The melt flow rate (MFR) of the crystalline propylene polymer (B) is preferably 0.1 to 50 g / 10 min, more preferably 0.5 to 30 g / 10 min, even more preferably 1 to 20 g / 10 min, and particularly preferably 3 to 15 g / 10 min. The MFR of the polymer (B) is measured in accordance with ASTM D-1238-65T under conditions of 230°C and a load of 2.16 kg. A composition containing the polymer (B) having an MFR in the above range has excellent fluidity and can form a molded article with, for example, excellent appearance.

[0038] In the composition of the present disclosure, the content of the crystalline propylene polymer (B) is 10 to 55 mass%, preferably 15 to 50 mass%, more preferably 20 to 45 mass%, and even more preferably 25 to 40 mass%, based on 100 mass% of the total content of the polymer component (A), the crystalline propylene polymer (B), the vibration-damping component (C1), the vibration-damping component (C2), and the softener (D). By using such a composition, for example, a molded article having an excellent balance between hardness and basic physical properties can be produced.

[0039] The crystalline propylene polymer (B) may be synthesized by a conventionally known method. A commercially available product may be used as the crystalline propylene polymer (B). The crystalline propylene polymer (B) contained in the composition may be one type or two or more types.

[0040] <Vibration-damping material components (C1 and (C2)> The composition of the present disclosure contains a vibration-damping material component (C1) and a vibration-damping material component (C2).

[0041] The peak temperature of tan δ of the vibration-damping material component (C1) obtained by dynamic viscoelasticity measurement is less than 10° C., preferably −40° C. or higher and lower than 10° C., more preferably −30° C. or higher and 9.8° C. or lower, and even more preferably −20° C. or higher and 9.5° C. or lower. The vibration-damping material component (C1) is a component that contributes to vibration-damping properties in the low temperature range.

[0042] The peak temperature of tan δ of the vibration-damping material component (C2) obtained by dynamic viscoelasticity measurement is 10° C. or higher, preferably 12 to 60° C., more preferably 14 to 50° C., and even more preferably 16 to 45° C. The vibration-damping material component (C2) is a component that contributes to vibration-damping properties in the high temperature range.

[0043] Details of the dynamic viscoelasticity measurement are described in the Examples section. The peak temperature of tan δ is the temperature at which the loss tangent (tan δ) reaches its maximum value in the range of -60°C to 50°C, which is the measurement temperature for dynamic viscoelasticity measurement. The peak temperature of tan δ of the vibration-damping material component corresponds to the glass transition temperature (Tg) of the vibration-damping material component.

[0044] The composition of the present disclosure contains the above-mentioned polymer component (A), crystalline propylene-based polymer (B), and softener (D), as well as vibration-damping material components (C1) and (C2). By using such a composition, it is possible to produce a molded article that has excellent vibration-damping properties and can effectively suppress noise generation, particularly a molded article that has excellent vibration-damping properties over a wide temperature range and can effectively suppress noise generation.

[0045] The melt flow rates (MFR) of the vibration-damping components (C1) and (C2) are each independently preferably 0.1 to 50 g / 10 min, more preferably 0.5 to 30 g / 10 min, even more preferably 1 to 20 g / 10 min, and particularly preferably 3 to 15 g / 10 min. The MFR of the vibration-damping components (C1) and (C2) is measured in accordance with ASTM D-1238-65T at 230°C under a load of 2.16 kg. A composition containing the vibration-damping components (C1) and (C2) having an MFR within the above range has excellent fluidity and can form molded articles with excellent appearance, for example.

[0046] In the composition of the present disclosure, the content of the vibration-damping component (C2) is preferably 20 to 500 parts by mass, more preferably 33 to 300 parts by mass, even more preferably 50 to 200 parts by mass, and particularly preferably 80 to 125 parts by mass, per 100 parts by mass of the vibration-damping component (C1). A composition in which the relative contents of the vibration-damping components (C1) and (C2) fall within such ranges can, for example, achieve both vibration-damping properties over a wide temperature range and moldability.

[0047] In the composition of the present disclosure, the total content of the vibration-damping material component (C1) and the vibration-damping material component (C2) is 10 to 25 mass%, preferably 12 to 24 mass%, and more preferably 15 to 23 mass%, based on 100 mass% of the total content of the polymer component (A), the crystalline propylene-based polymer (B), the vibration-damping material component (C1), the vibration-damping material component (C2), and the softener (D). By using such a composition, for example, a molded article having excellent vibration-damping properties, effective noise suppression, and excellent appearance can be produced. If the content is less than 10 mass%, the vibration-damping properties tend to be insufficient over a wide temperature range, and the noise generation tends to be ineffectively suppressed. If the content is more than 25 mass%, the resulting molded article tends to have a poor appearance.

[0048] The vibration-damping material components (C1) and (C2) may be synthesized by a conventionally known method. Commercially available products may be used as the vibration-damping material components (C1) and (C2). The vibration-damping material component (C1) contained in the composition may be one type or two or more types. The vibration-damping material component (C2) contained in the composition may be one type or two or more types.

[0049] Examples of the vibration-damping material components (C1) and (C2) include thermoplastic elastomers. Examples of the thermoplastic elastomers include vinyl aromatic monomer-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyvinyl chloride-based thermoplastic elastomers, urethane-based thermoplastic elastomers, and polyester-based thermoplastic elastomers. Among these, at least one selected from vinyl aromatic monomer-based thermoplastic elastomers and olefin-based thermoplastic elastomers is preferred.

[0050] Examples of vinyl aromatic monomer-based thermoplastic elastomers include hydrogenated block copolymers having at least one block A primarily composed of vinyl aromatic monomer units and at least one block B primarily composed of conjugated diene monomer units. In the following description, hydrogenation is also referred to as "hydrogenation." Block A is, for example, a hard segment that imparts strength. A hydrogenated version of block B is, for example, a soft segment that imparts rubber elasticity.

[0051] The term "vinyl aromatic monomer unit" refers to a structural unit resulting from the polymerization of a vinyl aromatic monomer, i.e., a structural unit derived from a vinyl aromatic monomer. The term "vinyl aromatic monomer" refers to a compound having a vinyl group and an aromatic ring such as a benzene ring. The vinyl group is preferably bonded to the aromatic ring. In this specification, the term "vinyl group" refers to a vinyl group in a broad sense, including not only a vinyl group (HC=CH-) in the narrow sense, but also a vinylidene group (HC=C<) and a vinylene group (-HC=CH-). The term "conjugated diene monomer unit" refers to a structural unit resulting from the polymerization of a conjugated diene monomer, that is, a structural unit derived from a conjugated diene monomer.

[0052] The term "block A containing vinyl aromatic monomer units as a major component" refers to a block containing vinyl aromatic monomer units in an amount of preferably more than 50% by mass, more preferably 55% by mass or more, even more preferably 60% by mass or more, and particularly preferably 70% by mass or more. The content of vinyl aromatic monomer units in block A may be, for example, 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, or 98% by mass or more. Block A may be, for example, a block consisting of vinyl aromatic monomer units. Block A may further contain other monomer units such as conjugated diene monomer units. The term "block B containing conjugated diene monomer units as a main component" refers to a block containing conjugated diene monomer units in an amount of preferably more than 50% by mass, more preferably 55% by mass or more, even more preferably 60% by mass or more, and particularly preferably 70% by mass or more. The content of conjugated diene monomer units in block B may be, for example, 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, or 98% by mass or more. Block B may be, for example, a block consisting of conjugated diene monomer units. Block B may further contain other monomer units such as, for example, vinyl aromatic monomer units.

[0053] Examples of vinyl aromatic monomers include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N,N-dimethyl-p-aminoethylstyrene, and N,N-diethyl-p-aminoethylstyrene. Among these, styrene is preferred from the viewpoint of economic efficiency. One or more vinyl aromatic monomers may be used.

[0054] Examples of conjugated diene monomers include 1,3-butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, and 1,3-hexadiene. Among these, butadiene and isoprene are preferred from the viewpoint of economic efficiency. One or more types of conjugated diene monomers may be used.

[0055] The arrangement of each block in the block copolymer having block A and block B is not particularly limited. For example, block A is represented as "A" and block B is represented as "B". The block copolymer may be, for example, AB, A(BA) n1 (wherein n1 represents an integer of 1 to 3), and A(BAB) n2 (where n2 represents an integer of 1 to 2), etc.; (AB) n3 X (where n3 represents an integer of 3 to 6, and X represents a residue of a coupling agent such as silicon tetrachloride, tin tetrachloride, or a polyepoxy compound). n1 represents ABA when n1 = 1, represents ABABA when n1 = 2, and represents ABABABA when n1 = 3. Among these, AB type 2 (diblock), ABA type 3 (triblock), and ABAB type 4 (tetrablock) linear block copolymers are preferred.

[0056] The content of vinyl aromatic monomer units in the block copolymer is preferably 30 to 80% by mass, more preferably 35 to 75% by mass, and even more preferably 40 to 70% by mass. A hydrogenated block copolymer having a vinyl aromatic monomer unit content equal to or greater than the above lower limit tends to have excellent mechanical properties. A hydrogenated block copolymer having a vinyl aromatic monomer unit content equal to or less than the above upper limit tends to have excellent low-temperature properties. The content of vinyl aromatic monomer units is measured by nuclear magnetic resonance spectroscopy (NMR).

[0057] From the viewpoint of mechanical strength, the content of block A in the block copolymer is preferably 35% by mass or more, more preferably 45 to 65% by mass. The content of block A is calculated using the mass of block A obtained by a method of oxidatively decomposing a copolymer before hydrogenation with tert-butyl hydroperoxide using osmium tetroxide as a catalyst (the method described in I.M. Kolthoff, et al., J. Polym. Sci. 1, 429 (1946)) (excluding polymers of vinyl aromatic monomers having an average degree of polymerization of about 30 or less) according to the formula: content of block A (mass %) = (mass of block A in copolymer before hydrogenation / mass of copolymer before hydrogenation) × 100.

[0058] When the block copolymer contains a plurality of blocks A, the molecular weights and structural compositions of the blocks A may be the same or different. When the block copolymer contains a plurality of blocks B, the molecular weights and structural compositions of the blocks B may be the same or different.

[0059] The boundaries or edges of each block do not necessarily need to be clearly distinguished. Block A may be a copolymer block containing two or more types of vinyl aromatic monomer units. Block A may also be a copolymer block containing vinyl aromatic monomer units and other monomer units. When block A is the latter copolymer block, the distribution of vinyl aromatic monomer units in block A is not particularly limited. The vinyl aromatic monomer units may be distributed uniformly, or in a tapered, stepped, convex, or concave shape. Block B may be a copolymer block containing two or more types of conjugated diene monomer units. Block B may be a copolymer block containing conjugated diene monomer units and other monomer units. When block B is the latter copolymer block, the distribution of the conjugated diene monomer units in block B is not particularly limited. The conjugated diene monomer units may be distributed uniformly, or in a tapered, stepped, convex, or concave shape. Crystalline portions may be present in each block.

[0060] The vinyl bond content in the conjugated diene monomer units contained in the block copolymer is preferably 5 to 70 mol%, more preferably 10 to 50 mol%, even more preferably 10 to 30 mol%, and particularly preferably 10 to 25 mol%. The vinyl bond content refers to the total proportion of units in which the conjugated diene monomer is incorporated via 1,2-bonds or 3,4-bonds to the total amount of units in which the conjugated diene monomer is incorporated via 1,2-bonds, 3,4-bonds, or 1,4-bonds in the block copolymer (before hydrogenation). The vinyl bond content is measured by nuclear magnetic resonance spectroscopy (NMR).

[0061] The distribution of the conjugated diene monomer units incorporated via 1,2- or 3,4-bonds in each block is not particularly limited, and may be unevenly distributed. Examples of methods for controlling the distribution of the units include adding a vinylating agent during polymerization and changing the polymerization temperature.

[0062] In the hydrogenated product of the block copolymer, the hydrogenation rate of the unsaturated bonds contained in the conjugated diene monomer units is preferably 75 mol% or more, more preferably 80 mol% or more, even more preferably 85 mol% or more, still more preferably 90 mol% or more, and particularly preferably 95 mol% or more, from the viewpoints of heat resistance, aging resistance, and weather resistance. The hydrogenation rate of the unsaturated bonds is measured by nuclear magnetic resonance spectroscopy (NMR).

[0063] The hydrogenation catalyst used for hydrogenating the block copolymer may be any known hydrogenation catalyst, including, for example, (1) supported heterogeneous hydrogenation catalysts in which metals such as Ni, Pt, Pd, and Ru are supported on carbon, silica, alumina, or diatomaceous earth, (2) so-called Ziegler hydrogenation catalysts in which transition metal salts (e.g., organic acid salts or acetylacetone salts) of Ni, Co, Fe, Cr, and the like are used with reducing agents such as organoaluminum, and (3) homogeneous hydrogenation catalysts in which organometallic compounds (so-called organometallic complexes) of Ti, Ru, Rh, Zr, and the like are used. Specific examples of the hydrogenation catalyst include the hydrogenation catalysts described in JP-B Nos. 42-008704, 43-006636, 63-004841, 01-037970, 01-053851, 02-009041, and JP-A No. 08-109219.

[0064] Examples of vinyl aromatic monomer-based thermoplastic elastomers include hydrogenated styrene-based thermoplastic elastomers such as styrene-ethylene-butylene block copolymers (SEB), styrene-ethylene-butylene-styrene block copolymers (SEBS), and styrene-ethylene-propylene-styrene block copolymers (SEPS).

[0065] The method for adjusting the peak temperature of tan δ of the vinyl aromatic monomer-based thermoplastic elastomer to fall within the above range is not particularly limited, and examples thereof include a method of adjusting the content ratio of each block, the arrangement of each block, and the content ratio of each monomer unit in each block.

[0066] The vinyl aromatic monomer-based thermoplastic elastomer may be a commercially available product. The vinyl aromatic monomer-based thermoplastic elastomer may be synthesized by a conventionally known method. Examples of methods for synthesizing the block copolymer include those described in Japanese Patent Publication Nos. 36-019286, 43-017979, 46-032415, 49-036957, 48-002423, 48-004106, 56-028925, 59-166518, and 60-186577.

[0067] Examples of olefin-based thermoplastic elastomers include α-olefin copolymers such as 4-methyl-1-pentene-α-olefin copolymers. 4-methyl-1-pentene-α-olefin copolymers contain structural units derived from 4-methyl-1-pentene and structural units derived from an α-olefin other than 4-methyl-1-pentene. Hereinafter, α-olefins other than 4-methyl-1-pentene will also be referred to as "α-olefin (1)."

[0068] The α-olefin (1) is preferably an α-olefin having 2 to 20 carbon atoms. Examples of the α-olefin having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, 3-methyl-1-butene, and 3-methyl-1-pentene. From the viewpoints of copolymerizability with 4-methyl-1-pentene and the physical properties (stress relaxation property, etc.) of the resulting copolymer, the α-olefin (1) is preferably an α-olefin having 2 to 10 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, and 1-decene.

[0069] As the 4-methyl-1-pentene, biomass-derived 4-methyl-1-pentene may be used. As the α-olefin (1), biomass-derived α-olefin (1) may be used.

[0070] The content of the 4-methyl-1-pentene-derived structural units in the 4-methyl-1-pentene-α-olefin copolymer is preferably 50 to 95 mol %, more preferably 60 to 93 mol %, and even more preferably 70 to 90 mol %, based on the total content of the 4-methyl-1-pentene-derived structural units and the α-olefin (1)-derived structural units (100 mol %). 13 It is calculated from the C-NMR spectrum.

[0071] In the production of 4-methyl-1-pentene·α-olefin copolymer, one or more α-olefins (1) may be used. The 4-methyl-1-pentene·α-olefin copolymer has at least one structural unit derived from α-olefin (1), and may have two or more structural units derived from α-olefin (1).

[0072] The 4-methyl-1-pentene-α-olefin copolymer may further contain structural units derived from a polymerizable compound other than 4-methyl-1-pentene and the α-olefin (1). Examples of the polymerizable compound include cyclic olefins, aromatic vinyl compounds, vinyl ester compounds, unsaturated carboxylic acids, derivatives of unsaturated carboxylic acids, conjugated dienes, and non-conjugated polyenes.

[0073] The total content of the 4-methyl-1-pentene-derived structural units and the α-olefin (1)-derived structural units in the 4-methyl-1-pentene-α-olefin copolymer is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 98% by mass or more, of the total amount of structural units constituting the copolymer.

[0074] The α-olefin copolymer, such as 4-methyl-1-pentene-α-olefin copolymer, may be, for example, a random copolymer or a block copolymer. The α-olefin copolymer may be partially graft-modified with a polar monomer. Examples of such polar monomers include hydroxyl group-containing ethylenically unsaturated compounds, amino group-containing ethylenically unsaturated compounds, epoxy group-containing ethylenically unsaturated compounds, unsaturated carboxylic acids, unsaturated carboxylic acid derivatives, vinyl ester compounds, aromatic vinyl compounds, vinyl chloride, vinyl group-containing organosilicon compounds, and carbodiimide compounds.

[0075] The molecular weight distribution (Mw / Mn) of the α-olefin copolymer is preferably 1.0 to 3.5, more preferably 1.3 to 3.0, and even more preferably 1.5 to 2.5. Mw is the weight average molecular weight measured by gel permeation chromatography (GPC). Mn is the number average molecular weight measured by GPC. The molecular weight distribution (Mw / Mn) can be adjusted, for example, by the type of olefin polymerization catalyst described below.

[0076] The Mw and Mn of the α-olefin copolymer are calculated by a standard polystyrene conversion method using gel permeation chromatography (GPC). Measuring device: GPC (ALC / GPC 150-C plus type, Differential refractometer with integrated detector (Waters) Column: two GMH6-HT (Tosoh Corporation), and Two GMH6-HTL (Tosoh Corporation) connected in series Eluent: o-dichlorobenzene Column temperature: 140℃ Flow rate: 1.0mL / min

[0077] The α-olefin copolymer may be an amorphous copolymer having no melting point, or a crystalline copolymer having a melting point. In the case of a crystalline copolymer, the melting point is preferably 80 to 180°C, more preferably 100 to 160°C, even more preferably 110 to 150°C, and particularly preferably 120 to 140°C.

[0078] The melting point (Tm) of an α-olefin copolymer is measured using a differential scanning calorimeter (DSC) in accordance with JIS K7121 (2012). Specifically, pellets of the α-olefin copolymer are heated at 280°C for 10 minutes, then cooled from 280°C to -50°C at a rate of 10°C / min, held at -50°C for 1 minute, and then heated at a rate of 10°C / min. The temperature at the peak position of the crystalline melting peak in the DSC curve obtained by this heating is taken as the melting point (Tm). If multiple peaks are detected during DSC measurement, the temperature at the peak position of the peak detected at the highest temperature is taken as the melting point. If no crystalline melting peak is observed in the heating range from -50°C to 280°C, the α-olefin copolymer is described as having no melting point.

[0079] Methods for adjusting the melting point of the α-olefin copolymer within the above range or for making the α-olefin copolymer have no melting point include, for example, a method for adjusting the stereoregularity of the α-olefin copolymer using an olefin polymerization catalyst described below, and a method for adjusting the content ratio of each structural unit contained in the α-olefin copolymer.

[0080] The method for adjusting the peak temperature of tan δ of the 4-methyl-1-pentene-α-olefin copolymer to fall within the above range is not particularly limited, and examples thereof include a method of adjusting the composition ratio of the structural units derived from 4-methyl-1-pentene and the structural units derived from the α-olefin (1).

[0081] Commercially available α-olefin copolymers may be used. The α-olefin copolymers may be synthesized by conventional methods. For example, the α-olefin copolymers can be obtained by polymerizing at least an α-olefin in the presence of an olefin polymerization catalyst. Examples of the olefin polymerization catalyst include metallocene catalysts. Examples of the metallocene catalyst include those described in International Publication Nos. 01 / 53369, 01 / 27124, JP-A-3-193796, JP-A-02-41303, JP-A-2006 / 025540, and JP-A-2014 / 050817.

[0082] The vibration-damping material component (C1) is preferably a vinyl aromatic monomer-based thermoplastic elastomer, more preferably a hydrogenated product of the above-mentioned block copolymer, even more preferably a hydrogenated styrene-based thermoplastic elastomer, and particularly preferably at least one selected from SEB, SEBS, and SEPS. The vibration-damping material component (C2) is preferably at least one selected from vinyl aromatic monomer-based thermoplastic elastomers and olefin-based thermoplastic elastomers, more preferably at least one selected from hydrogenated products of the above-mentioned block copolymers and α-olefin copolymers, even more preferably at least one selected from hydrogenated styrene-based thermoplastic elastomers and α-olefin copolymers, and particularly preferably at least one selected from SEB, SEBS, SEPS, and 4-methyl-1-pentene-α-olefin copolymers.

[0083] <Softener (D)> The composition of the present disclosure contains a softener (D). By using the softener (D), for example, it is possible to adjust the fluidity of the composition or the hardness of a molded article formed from the composition.

[0084] As the softener (D), for example, a known softener blended in a rubber composition can be used. Examples of the softener (D) include petroleum-based softeners such as process oil, lubricating oil, paraffin, liquid paraffin, polyethylene wax, polypropylene wax, petroleum asphalt, and vaseline; coal tar-based softeners such as coal tar and coal tar pitch; fatty oil-based softeners such as castor oil, linseed oil, rapeseed oil, soybean oil, and coconut oil; tall oil; sub(factus); waxes such as beeswax, carnauba wax, and lanolin; fatty acids such as ricinoleic acid, palmitic acid, lauric acid, and stearic acid; barium stearate, stearyl alcohol, and the like. Examples of suitable lubricating oils include fatty acid salts such as calcium phosphate and zinc laurate; naphthenic acid; pine oil, rosin or its derivatives; synthetic polymer softeners such as terpene resin, petroleum resin, coumarone-indene resin, and atactic polypropylene; ester softeners such as dioctyl phthalate, dioctyl adipate, and dioctyl sebacate; microcrystalline wax, liquid polybutadiene, modified liquid polybutadiene, liquid polyisoprene, terminal-modified polyisoprene, hydrogenated terminal-modified polyisoprene, liquid thiokol, and hydrocarbon synthetic lubricating oils. Among these, process oils are preferred, and paraffin-based process oils are more preferred.

[0085] The softener (D) contained in the composition may be one type or two or more types.

[0086] In the composition of the present disclosure, the content of the softener (D) is 10 to 45 mass%, preferably 12 to 40 mass%, more preferably 14 to 35 mass%, and even more preferably 16 to 30 mass%, based on the total content of the polymer component (A), the crystalline propylene-based polymer (B), the vibration-damping material component (C1), the vibration-damping material component (C2), and the softener (D) (100 mass%). A composition having a content of the softener (D) within the above range tends to have excellent fluidity. When an oil-extended rubber containing the copolymer (A1) and a softener is used in preparing the composition, the softener is classified as the softener (D).

[0087] <Phenol resin crosslinking agent (E)> The phenolic resin-based crosslinking agent (E) is, for example, a thermally crosslinkable phenolic resin. The phenolic resin-based crosslinking agent (E) is a suitable crosslinking agent from the viewpoint of generating less decomposition products.

[0088] Examples of the phenolic resin-based crosslinking agent (E) include phenolic resins produced by condensation of phenols and aldehydes in an alkaline medium, phenolic resins produced by condensation of bifunctional phenolic dialcohols, and halogenated phenolic resins (halogenated phenolic resin-based crosslinking agents).

[0089] Examples of phenols include unsubstituted phenols and substituted phenols such as halogenated phenols and alkylphenols. The number of carbon atoms in the alkyl group in the alkylphenol may be, for example, 1 to 10 or 1 to 2. An example of the aldehydes is formaldehyde. Examples of bifunctional phenol dialcohols include dimethylolphenols substituted at the para position with an alkyl group, where the alkyl group in the dimethylolphenols may have 1 to 10 carbon atoms, or 5 to 10 carbon atoms. The halogen is preferably bromine. Halogenated resins include, for example, brominated resins.

[0090] Examples of the phenolic resin-based crosslinking agent (E) include alkylphenol formaldehyde resins, halogenated alkylphenol formaldehyde resins, and methylolated alkylphenol resins. Examples of halogenated alkylphenol formaldehyde resins include brominated alkylphenol formaldehyde resins. The halogen content in the halogenated alkylphenol formaldehyde resin is not particularly limited, but may be, for example, 2 to 10 mass%. The halogen content is preferably the bromine content.

[0091] As the phenolic resin-based crosslinking agent (E), from the viewpoint of crosslinking ability, alkylphenol formaldehyde resins and halogenated alkylphenol formaldehyde resins are preferred, halogenated alkylphenol formaldehyde resins are more preferred, and brominated alkylphenol formaldehyde resins are even more preferred.

[0092] For the phenolic resin-based crosslinking agent (E), reference may be made to the descriptions in U.S. Patent Nos. 3,287,440, 3,709,840, and 4,311,628. Commercially available phenolic resins may be used as the phenolic resin-based crosslinking agent (E).

[0093] The phenol resin-based crosslinking agent (E) constituting the polymer component (A) may be one type or two or more types.

[0094] From the viewpoint of obtaining a thermoplastic elastomer composition having excellent rubber elasticity and oil resistance, the total content of the crosslinked moieties derived from the phenolic resin-based crosslinking agent (E) and unreacted crosslinking agent (E) in the composition of the present disclosure is preferably 0.1 to 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 3 to 10 parts by mass, relative to 100 parts by mass of the total content of the polymer moieties derived from copolymer (A1) and unreacted copolymer (A1).

[0095] <Other ingredients> The composition of the present disclosure may further contain other components in addition to the components described above. Examples of other components include thermoplastic resins such as polyolefin resins (excluding copolymer (A1), crystalline propylene polymer (B), or resins corresponding to the vibration-damping material components (C1) and (C2) described above), crosslinking aids, activators for the phenolic resin crosslinking agent (E), and resin additives. One or more of each of the other components may be used.

[0096] Examples of resin additives include inorganic fillers, slip agents, antioxidants, ultraviolet absorbers, light stabilizers, conductivity imparting agents, antistatic agents, dispersants, flame retardants, antibacterial agents, acid acceptors, fillers, colorants, and thermally conductive fillers. One or more of each of the resin additives may be used.

[0097] The composition of the present disclosure may contain one type of other component, or may contain two or more types.

[0098] The composition of the present disclosure may further contain the thermoplastic resin. The content of the thermoplastic resin in the composition of the present disclosure is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, relative to 100 parts by mass of the total content of the polymer component (A) and the crystalline propylene-based polymer (B).

[0099] A crosslinking aid may be further used together with the phenolic resin-based crosslinking agent (E). By using a crosslinking aid together with the phenolic resin-based crosslinking agent (E), crosslinking properties tend to be further improved.

[0100] Examples of crosslinking aids include metal oxides such as zinc oxide, copper oxide, magnesium oxide, and calcium oxide; metal hydroxides such as magnesium hydroxide, calcium hydroxide, sodium hydroxide, lithium hydroxide, potassium hydroxide, and copper hydroxide; and metal carbonates such as magnesium carbonate, calcium carbonate, sodium carbonate, lithium carbonate, and potassium carbonate. Among these, from the viewpoint of crosslinking ability, metal oxides such as zinc oxide and metal hydroxides such as magnesium hydroxide and calcium hydroxide are preferred, and zinc oxide is more preferred. That is, it is preferred to use zinc oxide together with the phenolic resin-based crosslinking agent (E).

[0101] The composition may contain one type of crosslinking aid or two or more types of crosslinking aids. Cases in which the composition of the present disclosure contains a crosslinking aid are described below: From the viewpoints of crosslinkability, heat resistance, fluidity, etc., the total amount of the crosslinking aid in the composition of the present disclosure is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the total content of crosslinked moieties derived from the phenolic resin-based crosslinking agent (E) and unreacted crosslinking agent (E).

[0102] When a non-halogenated phenolic resin crosslinking agent is used as the phenolic resin crosslinking agent (E), an activator for the crosslinking agent (E) may be used together with the phenolic resin crosslinking agent (E). The activator is preferably a halogen donor. Examples of halogen donors include stannous chloride, ferric chloride, and chlorinated paraffin; as well as halogen-donating polymers such as chlorinated polyethylene and chlorosulfonated polyethylene. When a halogenated phenolic resin crosslinking agent is used as the phenolic resin crosslinking agent (E), a halogen donor may not be used.

[0103] The composition of the present disclosure may further contain inorganic filler.Such inorganic filler includes: silicon-containing filler such as silica, finely powdered silicic acid, talc, kaolinite, clay and diatomaceous earth; oxide-based filler such as alumina, magnesium oxide, barium oxide and calcium oxide; hydroxide-based filler such as aluminum hydroxide and magnesium hydroxide; calcium carbonate-based filler such as light calcium carbonate and heavy calcium carbonate; carbon-based filler such as carbon black and graphite; magnetic-based filler such as ferrite, iron and cobalt; conductive filler such as silver, gold, copper and alloy; and limestone.Among these, carbon black is preferred.

[0104] Cases in which the composition of the present disclosure contains an inorganic filler are described below: The content of the inorganic filler in the composition of the present disclosure is preferably 1 to 100 parts by mass, more preferably 2 to 30 parts by mass, and even more preferably 3 to 10 parts by mass, per 100 parts by mass of polymer component (A).

[0105] <Physical properties of thermoplastic elastomer composition> The thermoplastic elastomer composition of the present disclosure has a peak tan δ obtained by dynamic viscoelasticity measurement in the range of −5° C. to 10° C., preferably −2.5° C. to 7.5° C., and more preferably 0° C. to 5° C. Such a thermoplastic elastomer has excellent vibration damping properties over a wide temperature range, for example, in a range including 1000 Hz, which corresponds to automobile road noise, at an ambient temperature of 0 to 40° C. Details of the dynamic viscoelasticity measurement are described in the Examples section. The phrase "a composition has a tan δ peak in the range of -5°C to 10°C" means that the composition has a tan δ peak whose peak top temperature is located in the range of -5°C to 10°C.

[0106] The position of the tan δ peak in the above composition can be adjusted, for example, by the tan δ peak temperature of the vibration-damping component (C1), the tan δ peak temperature of the vibration-damping component (C2), and the contents of the vibration-damping components (C1) and (C2).

[0107] The thermoplastic elastomer composition of the present disclosure has a tan δ value of 0.2 or more, preferably 0.2 to 2.0, more preferably 0.2 to 1.0, and particularly preferably 0.2 to 0.5, in the range of -5°C to 10°C. Such a thermoplastic elastomer has excellent vibration-damping properties over a wide temperature range, for example, in a range including 1000 Hz, which corresponds to automobile road noise, at an ambient temperature of 0 to 40°C. Molded articles obtained from compositions having a tan δ of not more than the above upper limit have an excellent balance between vibration-damping properties and appearance.

[0108] The tan δ value of the above composition in the range of -5°C to 10°C can be adjusted, for example, by the peak tan δ temperature of the vibration-damping material component (C1), the peak tan δ temperature of the vibration-damping material component (C2), and the contents of the vibration-damping material components (C1) and (C2).

[0109] <Method of producing thermoplastic elastomer composition> The thermoplastic elastomer composition of the present disclosure can be produced, for example, by dynamically heat-treating a mixture containing copolymer (A1), crystalline propylene polymer (B), vibration-damping material components (C1), (C2), softener (D), phenolic resin-based crosslinking agent (E), and, if necessary, other components. In this way, the composition can be obtained by dynamically crosslinking the copolymer (A1) in the presence of the phenolic resin-based crosslinking agent (E).

[0110] In this specification, "dynamic heat treatment" refers to kneading the necessary components such as copolymer (A1) in a molten state, for example, while applying a shear force, and "dynamic crosslinking" refers to crosslinking by dynamic heat treatment. By dynamic crosslinking, at least a part of copolymer (A1) is crosslinked.

[0111] It is preferable to use a kneading device when kneading. Examples of the kneading device include an open-type mixing roll; and a closed-type Banbury mixer, a single-screw extruder, a twin-screw extruder, a kneader, and a continuous mixer. The order of adding each component when kneading is not particularly limited. It is preferable to perform the dynamic heat treatment in a closed-type kneading device.

[0112] In preparing the composition, an oil-extended rubber containing copolymer (A1) and softener (D) may be used. The softener (D) may be added during the preparation of the composition. When an oil-extended rubber is used and the softener (D) is added during the preparation of the composition, the softener contained in the oil-extended rubber and the softener added may be the same or different.

[0113] The Mooney viscosity ML(1+4)(125°C) of the oil-extended rubber is preferably 10 to 300, more preferably 20 to 200, and even more preferably 30 to 100. The Mooney viscosity ML(1+4)(125°C) is measured using a Mooney viscometer in accordance with JIS K6300-1(2013).

[0114] In the above production method, the blending amount of the phenolic resin-based crosslinking agent (E) is preferably 0.1 to 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 3 to 10 parts by mass, per 100 parts by mass of the copolymer (A1). When the blending amount of the phenolic resin-based crosslinking agent (E) is within the above range, the resulting composition is preferred because it has excellent rubber elasticity, oil resistance, and hardness.

[0115] When a crosslinking aid is used in the above production method, the blending amount of the crosslinking aid is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 20 parts by mass, per 100 parts by mass of the phenolic resin-based crosslinking agent (E), from the viewpoints of crosslinkability, heat resistance, flowability, etc.

[0116] In the above-mentioned production method, when a halogen donor is used as an activator together with the phenolic resin-based crosslinking agent (E), the amount of the halogen donor to be blended is such that the ratio of the phenolic resin-based crosslinking agent (E) to the halogen donor ((E) / halogen donor) is preferably 1 to 100, more preferably 2 to 50.

[0117] The dynamic heat treatment may be carried out in an inert gas atmosphere, such as nitrogen gas and carbon dioxide gas.

[0118] The heating temperature in the dynamic heat treatment is preferably 125 to 280° C., more preferably 145 to 240° C. The heating temperature is, for example, from the melting point of the crystalline propylene polymer (B) to 280° C. The kneading time in the dynamic heat treatment is preferably 1 to 30 minutes, more preferably 3 to 20 minutes. The shear force applied during the kneading is, for example, preferably at a maximum shear rate of 10 to 100,000 sec -1 , more preferably 100 to 50,000 seconds -1 , and more preferably 1,000 to 10,000 seconds -1 , and particularly preferably 2,000 to 7,000 seconds -1 The shear force is such that

[0119] [Molded body] The molded article of the present disclosure comprises the thermoplastic elastomer composition of the present disclosure. The thermoplastic elastomer composition and molded article of the present disclosure can be widely used in fields such as automobile parts, industrial machinery parts, home appliance parts, electric and electronic parts, and building materials.

[0120] The thermoplastic elastomer composition of the present disclosure can be molded by various known molding methods, such as extrusion molding, injection molding, compression molding, calendar molding, vacuum molding, press molding, stamping molding, and blow molding. Examples of blow molding include press blow molding, direct blow molding, and injection blow molding.

[0121] The molded article of the present disclosure is suitable for applications requiring, for example, suppression of noise such as road noise, or vibration-damping or sound insulation, particularly applications requiring suppression of noise over a wide temperature range, or vibration-damping or sound insulation. The molded article of the present disclosure is therefore suitable as an automobile part, effectively suppressing noise generated during vehicle operation. Examples of automobile parts include engine seals, glass run channels, hole plugs, and hoses.

[0122] [Example of situation] The present disclosure relates to, for example, the following [1] to [8]. [1] A thermoplastic elastomer composition, comprising a polymer component (A), a crystalline propylene-based polymer (B), a vibration-damping material component (C1), a vibration-damping material component (C2), and a softener (D), the polymer component (A) comprises a crosslinked product in which at least a portion of an ethylene-α-olefin having 3 or more carbon atoms-non-conjugated polyene copolymer (A1) is crosslinked with a phenolic resin-based crosslinking agent (E); the peak temperature of tan δ of the vibration-damping material component (C1) obtained by dynamic viscoelasticity measurement is less than 10°C, and the peak temperature of tan δ of the vibration-damping material component (C2) obtained by dynamic viscoelasticity measurement is 10°C or higher; the composition has a peak of tan δ obtained by dynamic viscoelasticity measurement in the range of −5° C. to 10° C., and the value of tan δ in the range of −5° C. to 10° C. is 0.2 or more; the content of the polymer component (A) is 15 to 40 mass%, the content of the crystalline propylene polymer (B), the vibration-damping component (C1), the vibration-damping component (C2), and the softener (D) is 100 mass%, the total content of the vibration-damping component (C1) and the vibration-damping component (C2) is 10 to 25 mass%, and the content of the softener (D) is 10 to 45 mass%, Thermoplastic elastomer composition. [2] The thermoplastic elastomer composition according to [1], wherein at least one selected from the vibration-damping component (C1) and the vibration-damping component (C2) is a hydrogenated product of a block copolymer having at least one block A mainly containing vinyl aromatic monomer units and at least one block B mainly containing conjugated diene monomer units. [3] The thermoplastic elastomer composition according to [2], wherein the content of the block A in the block copolymer is 35% by mass or more. [4] The thermoplastic elastomer composition according to [2] or [3], wherein the vibration-damping component (C1) is a hydrogenated product of the block copolymer, and the vibration-damping component (C2) is at least one selected from the group consisting of a hydrogenated product of the block copolymer and an α-olefin copolymer. [5] The thermoplastic elastomer composition according to any one of the above [1] to [4], wherein the α-olefin in the copolymer (A1) is an α-olefin having 3 to 20 carbon atoms. [6] The thermoplastic elastomer composition according to any one of the above [1] to [5], wherein the phenolic resin-based crosslinking agent (E) is a halogenated phenolic resin-based crosslinking agent. [7] A molded article comprising the thermoplastic elastomer composition according to any one of [1] to [6]. [8] The molded article according to [7] above, which is an automobile part. [Example]

[0123] The thermoplastic elastomer composition of the present disclosure will be described in more detail below based on examples, but the composition of the present disclosure is not limited to the examples. In the following description, "parts" are based on mass unless otherwise specified.

[0124] [component] The components used in the following examples and comparative examples are as follows: <Ethylene-α-olefin-non-conjugated polyene copolymer (A1) oil-extended> Copolymer (A-1) oil-extended product Ethylene-propylene-non-conjugated diene copolymer rubber, product name: Mitsui EPT 3072EPM, manufactured by Mitsui Chemicals, Inc., content of ethylene-derived structural units = 64 mass%, content of non-conjugated diene-derived structural units = 5.4 mass%, non-conjugated diene: 5-ethylidene-2-norbornene (ENB), Mooney viscosity ML(1+4)(125°C) = 51, oil extension amount = 40 (PHR)

[0125] <Crystalline propylene polymer (B)> Propylene polymer (B-1) Propylene homopolymer, trade name: EL-Pro P701J, manufactured by SCG Chemicals Co., Ltd., MFR (230°C, 2.16 kg load): 9 g / 10 min, melting point: 163°C

[0126] <Vibration-damping material components> Vibration-damping component (C1-1) Hydrogenated styrene-based thermoplastic elastomer (SEBS), trade name: SOE S1611, manufactured by Asahi Kasei Corporation, MFR (190°C, 2.16 kg load): 4.0 g / 10 min, peak temperature of tan δ: 9°C Vibration-damping material component (C1-2) Hydrogenated styrene-based thermoplastic elastomer (SEBS), product name: SOE S1606, manufactured by Asahi Kasei Corporation, MFR (230°C, 2.16 kg load): 4.0 g / 10 min, peak temperature of tan δ: -13°C Vibration-damping component (C2-1) α-olefin copolymer, trade name: ABSORTOMER EP1013, manufactured by Mitsui Chemicals, Inc., MFR (230°C, 2.16 kg load): 10 g / 10 min, peak temperature of tan δ: 40°C Vibration-damping component (C2-2) Hydrogenated styrene-based thermoplastic elastomer (SEBS), trade name: SOE S1605, manufactured by Asahi Kasei Corporation, MFR (230°C, 2.16 kg load): 5.0 g / 10 min, peak temperature of tan δ: 18°C

[0127] <Softener (D)> Softener (D-1) Paraffin-based process oil, Product name: Diana Process Oil PW-100, manufactured by Idemitsu Kosan Co., Ltd.

[0128] <Phenol resin crosslinking agent (E)> Crosslinking agent (E-1) Brominated alkylphenol formaldehyde resin, product name: SP-1055F, SI Group Inc.

[0129] <Other ingredients> Crosslinking agent: Zinc oxide (zinc oxide type 2), manufactured by Hakusui Tech Co., Ltd. Carbon black masterbatch: PE4993, manufactured by Cabot

[0130] The composition and physical properties of each of the above components were measured by the following methods.

[0131] <Content ratio of constituent units> The content (mass%) of each structural unit contained in copolymer (A1) is 13 The values were calculated from the C-NMR spectrum. 13 C-NMR spectra were obtained using an ECX400P nuclear magnetic resonance spectrometer (manufactured by JEOL Ltd.) under the following conditions: measurement temperature: 120°C, measurement solvent: orthodichlorobenzene / deuterated benzene = 4 / 1 (volume ratio), and number of accumulations: 8000.

[0132] <Mooney viscosity> The Mooney viscosity ML(1+4)(125°C) of the copolymer (A1) oil product was measured in accordance with JIS K6300-1(2013) using a Mooney viscometer (Model SMV202 manufactured by Shimadzu Corporation).

[0133] <Melt flow rate (MFR)> The MFR of the crystalline propylene-based polymer (B) was measured under the conditions of 230°C and a load of 2.16 kg in accordance with ASTM D-1238-65T. The MFRs of the vibration damping material components (C1) and (C2) were measured under the conditions of 230°C or 190°C and a load of 2.16 kg in accordance with ASTM D-1238-65T.

[0134] <Melting point> The melting point of the crystalline propylene-based polymer (B) was measured using a differential scanning calorimeter (DSC) in accordance with JIS K7121(2012). Specifically, the pellets of the above polymer (B) were heated at 200°C for 10 minutes, then cooled from 200°C to 30°C at a rate of 10°C / min and held at 30°C for 1 minute, and then heated at a rate of 10°C / min. The temperature at the peak position of the crystal melting peak in the DSC curve obtained by this heating was taken as the melting point (Tm). When multiple peaks were detected during the DSC measurement, the temperature at the peak position of the peak detected on the highest temperature side was taken as the melting point.

[0135] <tanδ and its peak temperature> The tan δ and peak temperature of each of the vibration-damping components (C1) and (C2) were measured using a viscoelasticity measuring device (ARES-G2, manufactured by TA Instruments) as follows. The vibration-damping components were sheet-molded at 10 MPa using a hydraulic heat press (manufactured by Shinto Metal Industries) set at 190°C to produce a 2.0 mm thick pressed sheet. From this pressed sheet, a rectangular molded product measuring 4 mm wide x 15 mm long x 2 mm thick was cut. The rectangular molded product was tested in torsion mode, and tan δ was measured when scanned from -60°C to 50°C under conditions of 0.01°C strain, 1.0 Hz frequency, and 5.0°C / min heating rate, and the peak temperature of tan δ was determined.

[0136] [Example 1] 35 parts of oil-extended copolymer (A-1), 32 parts of propylene polymer (B-1), 10 parts of vibration-damping component (C1-1), 10 parts of vibration-damping component (C2-1), 10 parts of softener (D-1), 1.5 parts of crosslinking agent (E-1), 0.15 parts of crosslinking coagent, and 1.3 parts of carbon black masterbatch were kneaded using an extruder (product number: KTX-30, manufactured by Kobe Steel, Ltd.) with the following settings, and the resulting kneaded mixture was subjected to dynamic crosslinking treatment. In this way, pellets of thermoplastic elastomer composition were obtained. The oil-extended copolymer (A-1) contained 25 parts of copolymer (A-1) and 10 parts of oil-extended oil.

[0137] The extruder settings are as follows: Cylinder temperature: C1: 50°C, C2: 90°C, C3: 100°C, C4: 120°C, C5: 180°C, C6: 200°C, C7 to C14: 200°C, die temperature: 200°C, screw rotation speed: 500 rpm, extrusion rate: 40 kg / h

[0138] [Examples 2 to 4 and Comparative Examples 1 to 6] Pellets of thermoplastic elastomer compositions were obtained in the same manner as in Example 1, except that the types and amounts of the components used were changed as shown in Table 1. The numerical values in the "blending" column in Table 1 indicate parts by mass.

[0139] The above thermoplastic elastomer compositions were evaluated according to the following description.

[0140] [tanδ and its peak temperature] The tan δ and peak temperature of the thermoplastic elastomer composition were measured using a viscoelasticity measuring device (ARES-G2, manufactured by TA Instruments) as follows. Using a hydraulic heat press manufactured by Shinto Metal Industries Co., Ltd. set at 190°C, pellets of the thermoplastic elastomer composition were sheet-molded at a pressure of 10 MPa to produce a 2.0 mm thick pressed sheet. From this pressed sheet, a rectangular molded article measuring 4 mm wide, 15 mm long, and 2 mm thick was cut. The rectangular molded article was tested in torsion mode, and tan δ was measured when scanned from -60°C to 50°C under conditions of 0.01°C strain, 1.0 Hz frequency, and 5.0°C / min heating rate, and the peak temperature of tan δ was determined. A rating of A was given when the minimum value of tan δ in the range of -5°C to 10°C was 0.2 or more, and a rating of B was given when the minimum value of tan δ in the range of -5°C to 10°C was less than 0.2.

[0141] [hardness] The thermoplastic elastomer composition pellets obtained in the Examples and Comparative Examples were press-molded at 230°C for 6 minutes using a 100t electric automatic press (manufactured by Shoji Co., Ltd.), followed by cooling and pressing at room temperature for 5 minutes to obtain a 2mm-thick pressed sheet. In accordance with JIS K6253-3 (2023), a sample was prepared by stacking three of the above 2mm-thick pressed sheets, and the Type A hardness (instantaneous value) of the sample was measured using a durometer.

[0142] [exterior] Pellets of the thermoplastic elastomer compositions obtained in the Examples or Comparative Examples were molded at 200°C using a 140t injection molding machine (manufactured by Nissei Plastic Industrial Co., Ltd.) to produce plate-like molded articles measuring 150 mm wide x 120 mm long x 2 mm thick. The appearance of the plate-like molded articles was observed, and an A rating was given if no white wavy flow marks were observed, and a B rating was given if such flow marks were observed.

[0143] [Road noise suppression effect] Pellets of the thermoplastic elastomer composition obtained in the examples or comparative examples were molded at 230°C using a press molding machine to produce plate-like molded articles measuring 100 mm wide, 100 mm long, and 2 mm thick. White noise was emitted from the space above one side of the plate-like molded article, and the sound was detected using a sound collector installed in the space above the other side of the plate-like molded article. The surrounding area of the plate-like molded article was shielded to prevent sound transmission. A sound insulation of 20 dB or more at 1000 Hz was judged to have vibration-damping and road noise suppression effects. When measurements were performed at ambient temperatures of 0°C and 40°C and the road noise suppression effect was judged to be "present," the vibration-damping and road noise suppression effects were judged to be "present" over a wide temperature range, and a rating of A was given. When measurements were performed at ambient temperatures of 0°C and 40°C and the vibration-damping and road noise suppression effects were not judged to be "present" at at least one of the temperatures, the vibration-damping and road noise suppression effects were judged to be "absent" over a wide temperature range, and a rating of B was given.

[0144] [Table 1]

Claims

1. A thermoplastic elastomer composition comprising: The composition comprises: A polymer component (A), A crystalline propylene polymer (B), a vibration-damping material component (C1); a vibration-damping component (C2); A softener (D), Contains the polymer component (A) comprises a crosslinked product in which at least a portion of an ethylene-α-olefin having 3 or more carbon atoms-non-conjugated polyene copolymer (A1) is crosslinked with a phenolic resin-based crosslinking agent (E); the vibration-damping material component (C1) has a peak temperature of tan δ obtained by dynamic viscoelasticity measurement of less than 10°C, and the vibration-damping material component (C2) has a peak temperature of tan δ obtained by dynamic viscoelasticity measurement of 10°C or higher; the composition has a peak of tan δ measured by dynamic viscoelasticity measurement in the range of −5° C. to 10° C., and the value of tan δ in the range of −5° C. to 10° C. is 0.2 or more; In a total of 100% by mass of the polymer component (A), the crystalline propylene-based polymer (B), the vibration-damping material component (C1), the vibration-damping material component (C2), and the softener (D), The content of the polymer component (A) is 15 to 40% by mass, the content of the crystalline propylene polymer (B) is 10 to 55% by mass, the total content of the vibration-damping component (C1) and the vibration-damping component (C2) is 10 to 25 mass %, The content of the softener (D) is 10 to 45 mass%. Thermoplastic elastomer composition.

2. 2. The thermoplastic elastomer composition according to claim 1, wherein at least one selected from the vibration-damping component (C1) and the vibration-damping component (C2) is a hydrogenated product of a block copolymer having at least one block A mainly containing vinyl aromatic monomer units and at least one block B mainly containing conjugated diene monomer units.

3. The thermoplastic elastomer composition according to claim 2 , wherein the content of the block A in the block copolymer is 35% by mass or more.

4. the vibration-damping material component (C1) is a hydrogenated product of the block copolymer, the vibration-damping material component (C2) is at least one selected from the group consisting of a hydrogenated product of the block copolymer and an α-olefin copolymer; The thermoplastic elastomer composition according to claim 2.

5. 2. The thermoplastic elastomer composition according to claim 1, wherein the α-olefin in the copolymer (A1) is an α-olefin having 3 to 20 carbon atoms.

6. The thermoplastic elastomer composition according to claim 1, wherein the phenolic resin-based crosslinking agent (E) is a halogenated phenolic resin-based crosslinking agent.

7. A molded article comprising the thermoplastic elastomer composition according to any one of claims 1 to 6.

8. The molded article according to claim 7, which is an automobile part.

Images