Thermoplastic elastomer composition

Abstract

The present invention relates to providing a novel thermoplastic elastomer composition that has excellent sealing properties even in applications where multiple openings and closings are expected, such as the service holes mentioned above, and also has excellent hot-melt coating properties. [Solution] A thermoplastic elastomer composition comprising the following components A to C, wherein component A has a melt mass flow rate of 5 g / 10 min or more at 230°C and 21.2 N, and component B has a melting point of 130°C or higher and a heat of fusion (ΔH) of 20 J / g or higher. Component A: Hydrogenated block copolymer containing polymer block a containing structural units derived from aromatic vinyl compounds and polymer block b containing structural units derived from conjugated diene compounds. Component B: Crystalline polyolefin resin Ingredient C: Softener

Description

[Technical Field]

[0001] The present invention relates to a thermoplastic elastomer composition, a method for producing the same, a composite using the composition, and a method for producing the same. [Background technology]

[0002] Conventionally, a method has been proposed to apply hot melt adhesive using a robot equipped with a discharge nozzle, with the aim of providing an application method that can automatically apply adhesive safely and quickly when attaching a door service hole cover to the inner panel of a door (Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2-86871 [Overview of the project] [Problems that the invention aims to solve]

[0004] The present invention relates to providing a novel thermoplastic elastomer composition that has excellent sealing properties even in applications where multiple openings and closings are expected, such as the service holes mentioned above, and also has excellent hot-melt coating properties. [Means for solving the problem]

[0005] The present invention relates to the following [1] to

[11] . [1] A thermoplastic elastomer composition comprising the following components A to C, wherein component A has a melt mass flow rate of 5 g / 10 min or more at 230°C and 21.2 N, and component B has a melting point of 130°C or higher and a heat of fusion (ΔH) of 20 J / g or higher. Component A: Hydrogenated block copolymer containing polymer block a containing structural units derived from aromatic vinyl compounds and polymer block b containing structural units derived from conjugated diene compounds. Component B: Crystalline polyolefin resin Ingredient C: Softener [2] The thermoplastic elastomer composition according to [1], wherein component A comprises component A1, in which, among the structural units derived from the conjugated diene compound contained in the polymer block b, conjugated diene compound units having a side-chain alkyl group account for 40 mol% or more. [3] The thermoplastic elastomer composition according to [1] or [2], wherein the content of component A1 in component A is 50% by mass or more. [4] The thermoplastic elastomer composition according to any one of [1] to [3], wherein the melt mass flow rate of component B at 230°C and 21.2N is 10 g / 10 min or more. [5] The thermoplastic elastomer composition according to any one of [1] to [4], wherein the content of component B is 1 to 95 parts by mass per 100 parts by mass of component A. [6] The thermoplastic elastomer composition according to any one of [1] to [5], wherein the content of component C is 5 to 400 parts by mass per 100 parts by mass of component A. [7] The thermoplastic elastomer composition according to any one of [1] to [6], wherein the total content of component A, component B, and component C is 50 to 100% by mass. [8] A thermoplastic elastomer composition according to any one of [1] to [7], wherein the melt viscosity measured by a Brookfield viscometer at 210°C is 100 Pa·s or less. [9] A thermoplastic elastomer composition according to any one of [1] to [8] for forming a composite by heat-sealing it to a resin molded product, a rubber molded product, or a metal molded product. A method for producing a composite, comprising the step of applying a thermoplastic elastomer composition described in any of

[10] [1] to [9] to a resin molded product, a rubber molded product, or a metal molded product using a hot melt coating.

[11] A composite comprising a layer formed from any of the thermoplastic elastomer compositions described in [1] to [9] on the surface of a resin molded product, a rubber molded product, or a metal molded product. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a novel thermoplastic elastomer composition that has excellent sealing properties even in applications where multiple openings and closings are expected, such as the service holes described above, and also has excellent hot-melt coating properties. However, the effects of the present invention are not limited to the above embodiments and can also be achieved in applications where multiple openings and closings are not expected. [Modes for carrying out the invention]

[0007] While it is easy to obtain a thermoplastic elastomer composition with low melt viscosity suitable for hot-melt coating by selecting a hydrogenated block copolymer with low melt viscosity, such compositions generally have poor compression set and inferior long-term sealing properties. Therefore, the inventors diligently investigated and discovered that a thermoplastic elastomer composition containing a specific hydrogenated block copolymer with good miscibility with a crystalline polyolefin resin, a specific crystalline polyolefin resin, and a softener possesses suitable compression set and melt viscosity, that is, excellent long-term sealing retention and hot-melt coating properties. Although the mechanism is not clear, it is presumed that microdispersion of the crystalline polyolefin resin in the hydrogenated block copolymer is promoted, and the rigidity and heat resistance due to the crystalline phase of the crystalline polyolefin resin mechanically and thermally reinforce the polymer block b described later.

[0008] The thermoplastic elastomer composition of the present invention comprises the following components A to C, wherein component A has a melt mass flow rate of 5 g / 10 min or more at 230°C and 21.2 N, and component B has a melting point of 130°C or more and a heat of fusion (ΔH) of 20 J / g or more. Component A: Hydrogenated block copolymer containing polymer block a containing structural units derived from aromatic vinyl compounds and polymer block b containing structural units derived from conjugated diene compounds. Component B: Crystalline polyolefin resin Ingredient C: Softener

[0009] Component A in the thermoplastic elastomer composition of the present invention is a hydrogenated block copolymer containing polymer block a and polymer block b, which will be detailed below. Component A imparts mechanical and thermal properties and melt viscosity to the thermoplastic elastomer composition of the present invention.

[0010] Polymer block a contains structural units derived from aromatic vinyl compounds. Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, etc., and two or more of these may be used in combination. Among these, styrene which is easily available is preferable.

[0011] Polymer block a may contain a compound other than the aromatic vinyl compound as a monomer within the range not impairing the effects of the present invention. Examples of such a compound include ethylene, acrylonitrile, acrylate ester, vinyl acetate, etc.

[0012] The proportion of the structural units derived from the aromatic vinyl compound in all the structural units constituting polymer block a is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more.

[0013] The content of the structural units derived from the aromatic vinyl compound in component A is 5% by mass or more from the viewpoint of compression set, preferably 10% by mass or more, and more preferably 20% by mass or more. On the other hand, it is 60% by mass or less from the viewpoints of flexibility and sealing property, preferably 50% by mass or less, and more preferably 40% by mass or less. In the present specification, the content of the structural units derived from the aromatic vinyl compound can be measured by the method described in the examples.

[0014] Polymer block b contains structural units derived from conjugated diene compounds. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, etc., and two or more of these may be used in combination.

[0015] Polymer block b may contain compounds other than conjugated diene compounds as monomers, to the extent that the effects of the invention are not impaired. Examples of such compounds include styrene, α-olefins, isobutylene, farnesene, and the like.

[0016] The proportion of structural units derived from the conjugated diene compound among all structural units constituting polymer block b is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more. In this specification, the content of structural units derived from the conjugated diene compound can be measured by the method described in the examples.

[0017] The hydrogenated block copolymer of component A comprises at least one polymer block a and at least one polymer block b.

[0018] In component A, the bonding configuration of polymer block a and polymer block b is not particularly limited and may be linear, branched, radial, or a combination of two or more of these configurations. However, a linearly bonded configuration is preferred from the viewpoint of melt viscosity and mechanical strength. When polymer block a is represented as "A" and polymer block b as "B", (AB) l , A-(BA) m , A-(BA) n -A, B-(AB) n (wherein l, m, and n each independently represent an integer of 1 or more) The combination form is preferable, and from the viewpoint of compression set, (AB) l and A-(BA) m , A-(BA) n -The bonding configuration is more preferably represented by A, and even more preferably a bonding configuration of a triblock structure represented by ABA.

[0019] Also, when Component A has two or more polymer blocks a or two or more polymer blocks b, each polymer block a and polymer block b may be blocks having the same structure or different structures from each other. For example, in the triblock structure represented by [A-B-A], the two polymer blocks A may have the same or different types of aromatic vinyl compounds constituting them.

[0020] Also, when Component A is (A-B) l , A-(B-A) m , A-(B-A) n -A, B-(A-B) n (where l, m, and n each independently represent an integer of 1 or more), it may contain two or more block copolymers having different bonding forms. When it contains the diblock (A-B) l , from the viewpoint of compression set, in Component A, 30% by mass or less is preferable, 10% by mass or less is more preferable, and 1% by mass or less is still more preferable.

[0021] In Component A, the mass ratio of polymer block a to polymer block b (polymer block a / polymer block b) is preferably 5 / 95 to 70 / 30, more preferably 10 / 90 to 50 / 50, and still more preferably 15 / 85 to 40 / 60, from the viewpoints of flexibility and mechanical strength.

[0022] Substantially, Component A is one in which part or all of the unsaturated double bonds (carbon-carbon double bonds) in polymer block b are hydrogenated. The hydrogenation rate of polymer block b is preferably 85% or more, more preferably 90% or more, and still more preferably 95% or more. In the present invention, the hydrogenation rate of polymer block b can be determined by 1H-NMR spectrum. Component A may optionally have one or more functional groups such as carboxy group, hydroxy group, acid anhydride group, amino group, epoxy group, etc. in the molecular chain and / or at the molecular terminal, as long as the effects of the present invention are not impaired.

[0023] Specific examples of component A include styrene-ethylene-butylene block copolymer (SEB), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene block copolymer (SEP), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene block copolymer (SEEP), styrene-(ethylene-ethylene-propylene)-styrene block copolymer (SEEPS), (α-methylstyrene)-ethylene-butylene block copolymer, and (α-methylstyrene)-ethylene-butylene-(α-methylstyrene) block copolymer. These may be used individually or as a mixture of two or more, but from the viewpoint of compression set and melt viscosity, SEBS, SEPS, and SEEPS are preferred, with SEBS and SEPS being more preferred.

[0024] In component A, component A in which the amount of conjugated diene compound units having side-chain alkyl groups among the structural units derived from the conjugated diene compound contained in polymer block b is 40 mol% or more may be referred to as "component A1" in this specification. The amount of conjugated diene compound units having side-chain alkyl groups in component A1 is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, and even more preferably 70 to 100 mol%, among the structural units derived from the conjugated diene compound contained in polymer block b. Here, a conjugated diene compound unit having a side-chain alkyl group means, when the conjugated diene compound is butadiene, an ethyl group derived from 1,2-linked and 3,4-linked polybutadiene. When the conjugated diene compound is isoprene, it means a methyl group derived from 1,4-linked polyisoprene, or a methyl group and an ethyl group derived from 1,2-linked polyisoprene, or an isopropyl group derived from 3,4-linked polyisoprene. The side-chain alkyl groups contained in polymer block b impart low melt viscosity and miscibility with component B to component A. As a result, the thermoplastic elastomer composition of the present invention exhibits excellent coatability (low melt viscosity) and long-term sealing properties (compression set). For example, even if component A has the same composition, content, and weight-average molecular weight as polymer block a, if the content of side-chain alkyl groups in polymer block b is low, the melt viscosity will be high, resulting in insufficient coatability. Furthermore, improving coatability requires the use of a large amount of softening agent component C, which can lead to softening agent bleed-out (also called "oil bleed"), low hardness resulting in reduced resilience, and decreased sealing properties.

[0025] In the thermoplastic elastomer composition of the present invention, it is preferable that component A contains component A1 from the viewpoint of improving melt viscosity and mechanical strength and compression set through miscibility with component B. In the present invention, the content of side-chain alkyl groups in polymer block b can be determined by 13C-NMR spectroscopy. Furthermore, from the viewpoint of melt viscosity and miscibility with component B, the amount of component A1 in component A is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more. On the other hand, from the viewpoint of compression set, the amount of component A1 in component A is preferably 100% by mass or less, more preferably 99% by mass or less, and even more preferably 97% by mass or less.

[0026] In component A, from the viewpoint of miscibility with component C, the conjugated diene compound constituting polymer block b preferably contains 1% by mass or more of butadiene, more preferably 10% by mass or more, and even more preferably 20% by mass or more. It can also be 100% by mass or less, 90% by mass or less, etc.

[0027] From the viewpoint of compression set, the weight-average molecular weight of component A is preferably 20,000 or more, more preferably 30,000 or more, and even more preferably 50,000 or more. On the other hand, from the viewpoint of melt viscosity, the weight-average molecular weight of component A is preferably 150,000 or less, more preferably 120,000 or less, and even more preferably 80,000 or less. In this specification, the weight-average molecular weight (Mw) of component A can be measured by the method described in the examples.

[0028] The melt mass flow rate of component A at 230°C and 21.2N is related to the molecular weight of component A, the composition and content of polymer block a, etc., but in the case of component A, it is particularly highly correlated with the molecular structure, such as the amount of side-chain alkyl groups in polymer block b, and the melt mass flow rate increases as the amount of side-chain alkyl groups increases. In other words, it also serves as an indicator of the miscibility between polymer block b and component B, and is an important factor in achieving both the melt viscosity and compression set of the thermoplastic elastomer composition of the present invention. For these reasons, from the viewpoint of improving the compression set by miscibility with component B, it is preferable to have a melt mass flow rate of 5 g / 10 min or more, and from the viewpoint of mechanical strength, it is preferable to have a melt mass flow rate of 1000 g / 10 min or less. From these viewpoints, the range of the melt mass flow rate of component A at 230°C and 21.2N is preferably 10 to 700 g / 10 min, more preferably 15 to 500 g / 10 min, and even more preferably 20 to 250 g / 10 min. In this specification, the melt mass flow rate can be measured by the method described in the examples.

[0029] The content of component A in the thermoplastic elastomer composition of the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more, from the viewpoint of melt viscosity and compression set, while preferably 90% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less.

[0030] Component A can be manufactured by conventionally known methods. Component A is available as a commercially available product. Examples of commercially available products include the Kraton G series, Kraton FG series, Kraton MD series, and Kraton A series from Kraton Polymers, the ToughTec series and SOE series from Asahi Kasei, and the Septon series and Hybler series from Kuraray.

[0031] In the thermoplastic elastomer composition of the present invention, component B is a crystalline polyolefin resin. When component B is mixed with component A, an improvement in compression set is achieved. Here, resin is also called polymer, and refers to a polymer in which monomers constituting the polymer exceed 1,000 units, while polymers in which monomers are polymerized to 1,000 units are generally called oligomers. Due to these differences in molecular weight, component B, being a resin, has high crystallinity due to its molecular weight and constituent monomers, and therefore has higher viscosity, melting point, and heat of fusion compared to, for example, oligomers such as polyethylene wax and polypropylene wax. This property allows for mechanical and thermal reinforcement effects to be imparted to the thermoplastic elastomer composition of the present invention.

[0032] Examples of crystalline polyolefin resins that can be used as component B include known ones such as polyethylene homopolymers, polypropylene homopolymers, ethylene-propylene copolymers, α-olefin copolymers, and polyolefin resins modified with polar groups such as maleic acid. Among these, polypropylene homopolymers and ethylene-propylene copolymers are preferred from the viewpoint of compression set. From the viewpoint of miscibility, polypropylene homopolymers are even more preferred.

[0033] The melting point of component B is preferably 110°C or higher from the viewpoint of compression set, and preferably 200°C or lower from the viewpoint of miscibility. From these viewpoints, the melting point range of component B is more preferably 130 to 190°C, even more preferably 150 to 180°C, and even more preferably 160 to 170°C. In this specification, the melting point can be measured by the method described in the examples.

[0034] The heat of fusion (ΔH) of component B is 20 J / g or more. From the viewpoint of compression set, the heat of fusion is preferably 60 J / g or more, more preferably 82 J / g or more, and even more preferably 85 J / g or more. On the other hand, from the viewpoint of miscibility, the heat of fusion is preferably 150 J / g or less, more preferably 110 J / g or less, and even more preferably 100 J / g or less. In this specification, the heat of fusion can be measured by the method described in the examples.

[0035] The melt mass flow rate of component B at 230°C and 21.2N is an indicator that correlates with the molecular weight, for example, when component B is a homopolymer. A higher melt mass flow rate, i.e., a lower melt viscosity, corresponds to a lower molecular weight of component B. The miscibility between the polymer components, component A and component B, is better as the molecular weight decreases, and at the same time, the melt viscosity of the resulting thermoplastic elastomer composition can be reduced. On the other hand, if the molecular weight of component B becomes too low, the crystallinity of component B decreases. For these reasons, from the viewpoint of miscibility, it is preferably 10 g / 10 min or more, and from the viewpoint of compression set, it is preferably 5000 g / 10 min or less. From these viewpoints, the range of the melt mass flow rate of component B is preferably 30 to 3000 g / 10 min, more preferably 50 to 2500 g / 10 min, and even more preferably 100 to 2000 g / 10 min. In this specification, the melt mass flow rate can be measured by the method described in the examples.

[0036] In the thermoplastic elastomer composition of the present invention, the ratio of component A to component B is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, per 100 parts by mass of component A, from the viewpoint of melt viscosity and compression set. On the other hand, from the viewpoint of flexibility, the ratio of component B is preferably 95 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 70 parts by mass or less, per 100 parts by mass of component A.

[0037] The content of component B in the thermoplastic elastomer composition of the present invention is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, from the viewpoint of melt viscosity and compression set, while from the viewpoint of flexibility, it is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0038] Component B can be manufactured by conventionally known methods. Component B is available commercially. Examples of commercially available products include the PM series from Sun Allomer Co., Ltd., the Novatec PP series from Nippon Polypropylene Co., Ltd., and the Prime Polypropylene series from Prime Polymer Co., Ltd.

[0039] Component C in the thermoplastic elastomer composition of the present invention is a softening agent. Examples of component C include mineral oil-based softening agents such as paraffin oils, naphthenic oils, and asphalt oils; polyolefin synthetic softening agents such as 1-decene oligomers; plant-derived synthetic softening agents such as β-farnesene oligomers; vegetable oil-based softening agents such as fatty oils, pine root oils, tall oils, and Factis; coal tar-based softening agents such as tars and coumarone indene resins; and liquid or low molecular weight synthetic resins such as phenolic resin low condensates, low melting point styrene resins, polybutenes, and tertiary butylphenol acetylene condensates. Among these, paraffin oils, polyolefin synthetic softening agents, and plant-derived synthetic softening agents are preferred from the viewpoint of melt viscosity. Paraffin oil is even more preferred from the viewpoint of miscibility and bleed-out.

[0040] The kinematic viscosity of component C at 40°C is 10 mm from the standpoint of volatility. 2 Preferably 50,000 mm / s or more, and from the viewpoint of bleed-out. 2 Preferably less than / s, and 10000mm 2 / s or less is more preferable, and 1000mm 2 / s or less is even more preferable, and 500mm 2 A value of less than or equal to / s is even more preferable. From this viewpoint, the kinematic viscosity is preferably 20 to 300 mm². 2 / s, more preferably 30-200mm 2 / s, more preferably 50-100 mm 2 It is / s.

[0041] The content of component C is preferably 5 parts by mass or more per 100 parts by mass of component A, from the viewpoint of melt viscosity, and preferably 400 parts by mass or less from the viewpoint of bleed-out. From these viewpoints, the content of component C is preferably 5 to 400 parts by mass, more preferably 10 to 300 parts by mass, even more preferably 15 to 250 parts by mass, even more preferably 20 to 200 parts by mass, and even more preferably 25 to 150 parts by mass per 100 parts by mass of component A.

[0042] From the viewpoint of melt viscosity, the content of component C in the thermoplastic elastomer composition is preferably 5% by mass or more, and from the viewpoint of bleed-out, it is preferably 80% by mass or less. From this viewpoint, the content of component C in the thermoplastic elastomer composition is preferably 7 to 70% by mass, more preferably 10 to 60% by mass, and even more preferably 20 to 50% by mass.

[0043] The total content of component A, component B, and component C in the thermoplastic elastomer composition of the present invention is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, from the viewpoint of compression set. The upper limit may be 100% by mass, but in embodiments that include other components, it may be 98% by mass or less, 97% by mass or less, or 96% by mass or less.

[0044] The thermoplastic elastomer composition of the present invention may further contain an antioxidant as component D. Examples of component D include hindered phenol antioxidants, phosphorus antioxidants, sulfur antioxidants, aromatic amine antioxidants, and the like. By incorporating an antioxidant, the effect of preventing the deterioration of the mechanical properties of the thermoplastic elastomer composition of the present invention due to thermal degradation is achieved.

[0045] Examples of hindered phenol antioxidants include 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, hydroxymethyl-2,6-di-t-butylphenol, 2,6-di-t-α-dimethylamino-p-cresol, 2,5-di-t-butyl-4-ethylphenol, 4,4'-bis(2,6-di-t-butylphenol), 2,2'-methylene-bis-4-methyl-6-t-butylphenol, 2,2'-methylene-bis(4-ethyl-6-t-butylphenol), and 4,4 '-Methylene-bis(6-t-butyl-o-cresol), 4,4'-Methylene-bis(2,6-di-t-butylphenol), 2,2'-Methylene-bis(4-methyl-6-cyclohexylphenol), 4,4'-Butylidene-bis(3-methyl-6-t-butylphenol), 4,4'-Thiobis(6-t-butyl-3-methylphenol), Bis(3-methyl-4-hydroxy-5-t-butylbenzyl) sulfide, 4,4'-Thiobis(6-t-butyl-o-cresol), 2,2'-Thiobis(4-methyl-6-t-butylphenol), 2,6-Bis(2'-hydroxy-3'-t-butyl-5'-methylbenzyl)-4-methylphenol, 3,5-di-t-butyl-4-hydroxybenzenesulfonate diethyl ester, 2,2'-dihydroxy-3,3'-di(α-methylcyclohexyl)-5,5'-dimethyl-diphenylmethane, α-octadecyl-3(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, 6-(hydroxy-3,5-di-t-butylanilino)-2,4-bis-octyl-thio-1,3,5-triazine, hexamethylene glycol - Bis[β-(3,5-di-t-butyl-4-hydroxyphenol)propionate], N,N'-hexamethylene-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamic acid amide), 2,2-thio[diethyl-bis-3(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 3,5-di-t-butyl-4-hydroxybenzenephosphonate dioctadecyl ester, tetrakis[methylene-3(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, 1,3,5-trimethyl-2,4,6-tris(3,Examples include 5-di-t-butyl-4-hydroxybenzyl)benzene, 1,1,3-tris(2-methyl-4-hydroxy-5-di-t-butylphenyl)butane, tris(3,5-di-t-butyl-4-hydroxyphenyl)isocyanurate, and tris[β-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl-oxyethyl]isocyanurate, among which those with a molecular weight of 500 or more, such as tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, are preferred.

[0046] Examples of phosphorus-based antioxidants include phosphite compounds and phosphate compounds, among which phosphite compounds are preferred.

[0047] Examples of phosphite compounds include tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-1,6-hexamethylene-bis(N-hydroxyethyl-N-methyl semicarbazide)-diphosphite, tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-1,10-decamethylene-di-carboxylic acid-di-hydroxyethyl carbonylhydrazide-diphosphite, and tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl] Examples include [phenyl]-1,10-decamethylene-di-carboxylic acid-di-salisiloylhydrazide-diphosphite, tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-di(hydroxyethylcarbonyl)hydrazide-diphosphite, and tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-N,N'-bis(hydroxyethyl)oxamide-diphosphite, but in the present invention, phosphite compounds in which at least one PO bond or P=O bond is bonded to an aromatic group are preferred.Examples of such phosphite compounds include tris(2,4-di-t-butylphenyl) phosphite, tetrakis(2,4-di-t-butylphenyl)4,4'-biphenylene phosphate, bis(2,4-di-t-butylphenyl)pentaerythritol-di-phosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol-di-phosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite, and 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl). Examples include triphenyl-di-tridecyl) phosphite, 1,1,3-tris(2-methyl-4-ditridecylphosphite-5-t-butylphenyl)butane, tris(mixed mono and di-nonylphenyl) phosphite, tris(nonylphenyl) phosphite, 4,4'-isopropylidenebis(phenyl-dialkylphosphite), 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, etc.

[0048] Examples of sulfur-based antioxidants include sulfur-containing compounds such as thioethers, dithioates, mercaptobenzimidazoles, thiocarbanilides, and thiodipropion esters, with thioethers being preferred among these. Thioether antioxidants are compounds having at least one thioether bond in their molecular structure. Specifically, examples of thioether antioxidants include dilong-chain alkylthiodipropionates (dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, etc.) and tetrakis[methylene-3-(long-chain alkylthio)propionate]alkanes (e.g., tetrakis[methylene-3-(dodecylthio)propionate]methane, etc.). Long-chain alkyl groups include linear or branched alkyl groups having 8 to 20 carbon atoms. These thioether antioxidants can be used individually or in combination of two or more.

[0049] Examples of aromatic amine antioxidants include phenylnaphthylamine, 4,4'-dimethoxydiphenylamine, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, and 4-isopropoxydiphenylamine. Among these, aromatic secondary amine compounds are preferred, and diphenylamine compounds are more preferred.

[0050] The antioxidant content is preferably 0.05 to 20 parts by mass, preferably 1 to 15 parts by mass, and more preferably 2 to 10 parts by mass, per 100 parts by mass of component A.

[0051] The content of antioxidant D in the thermoplastic elastomer composition of the present invention is preferably 0.01 to 0.8% by mass, more preferably 0.1 to 0.4% by mass.

[0052] The thermoplastic elastomer composition of the present invention may optionally contain various additives other than component A, to the extent that they do not impair the effects of the present invention, such as thermoplastic elastomers other than component A, tackifiers, inorganic fillers (e.g., calcium carbonate, talc, silica), organic fillers (e.g., wood flour and cellulose powder, organic fibers), weather stabilizers, ultraviolet absorbers (e.g., benzotriazole, tridiamine, anilide, and benzophenone), heat stabilizers, anti-aging agents, light stabilizers (e.g., hindered amine and benzoate), antistatic agents, nucleating agents, pigments, adsorbents (e.g., metal oxides), metal chlorides (e.g., iron chloride and calcium chloride), hydrotalcite, aluminates, lubricants (e.g., fatty acids, higher alcohols, aliphatic amides, and aliphatic esters), flame retardants, foaming agents, and silicone compounds.

[0053] While tackifiers may be used to impart fusion strength, they tend to become sticky. In applications where multiple openings and closings are expected, it is preferable to either omit the tackifier or, if it is included, to use a small amount of it, in order to prevent a decrease in sealing performance due to the adhesion of dust and other debris. The tackifier content in the thermoplastic elastomer composition of the present invention is preferably 50% by mass or less, more preferably 20% by mass or less, even more preferably 5% by mass or less, and even more preferably 0% by mass. Examples of tackifiers include alicyclic hydrogenated tackifiers, rosin, modified rosin, or esters thereof, aliphatic petroleum resins, alicyclic petroleum resins, aromatic petroleum resins, copolymer petroleum resins of aliphatic and aromatic components, low molecular weight styrene resins, isoprene resins, alkylphenol resins, terpene resins, and chromanindene resins.

[0054] The A hardness (HsA) of the thermoplastic elastomer composition of the present invention, according to JIS K 6253, is preferably 5 points or higher, more preferably 15 points or higher, and even more preferably 30 points or higher, from the viewpoint of mechanical strength. Furthermore, from the viewpoint of flexibility and sealing properties, it is preferably 90 points or lower, more preferably 70 points or lower, and even more preferably 50 points or lower.

[0055] The melt mass flow rate of the thermoplastic elastomer composition of the present invention at 190°C and a 21.2N load, in accordance with JIS K 7210-1, is preferably 50 g / 10 min or more, more preferably 80 g / 10 min or more, and even more preferably 100 g / 10 min or more, from the viewpoint of coating properties.

[0056] The thermoplastic elastomer composition of the present invention preferably has heating and melting characteristics compatible with hot-melt coating machines. For example, thermoplastic elastomer compositions for extrusion molding and injection molding are melted by heating and compression kneading with strong shear force from a screw. However, thermoplastic elastomer compositions for hot-melt coating are required to melt after being placed in a heating pot and left to stand (without shear). For this reason, the heating and melting temperature of the thermoplastic elastomer composition of the present invention without shear is preferably 120°C or higher, more preferably 140°C or higher, and even more preferably 160°C or higher, from the viewpoint of sealing properties and compression set. Furthermore, from the viewpoint of preventing thermal degradation during coating, it is preferably 300°C or lower, more preferably 250°C or lower, and even more preferably 230°C or lower. The heating and melting temperature is measured at a temperature that can be measured with a Brookfield viscometer.

[0057] The melt viscosity of the thermoplastic elastomer composition of the present invention, as measured by a Brookfield viscometer at 170°C, is preferably 0.1 Pa·s or higher, more preferably 0.2 Pa·s or higher, and even more preferably 0.5 Pa·s or higher, from the viewpoint of formability (dimensional stability during coating). Furthermore, from the viewpoint of coatability, it is preferably 1000 Pa·s or lower, more preferably 500 Pa·s or lower, and even more preferably 100 Pa·s or lower. The melt viscosity of the thermoplastic elastomer composition of the present invention, as measured by a Brookfield viscometer at 190°C, is preferably 0.1 Pa·s or higher, more preferably 0.2 Pa·s or higher, and even more preferably 0.5 Pa·s or higher, from the viewpoint of formability. Furthermore, from the viewpoint of coating properties, it is preferably 500 Pa·s or lower, more preferably 100 Pa·s or lower, and even more preferably 50 Pa·s or lower. The melt viscosity of the thermoplastic elastomer composition of the present invention, as measured by a Brookfield viscometer at 210°C, is preferably 0.1 Pa·s or higher, more preferably 0.2 Pa·s or higher, and even more preferably 0.5 Pa·s or higher, from the viewpoint of formability. Furthermore, from the viewpoint of coatability, it is preferably 100 Pa·s or lower, more preferably 70 Pa·s or lower, and even more preferably 50 Pa·s or lower. The melt viscosity of the thermoplastic elastomer composition at each temperature is measured using a Brookfield viscometer by the method described in the examples below.

[0058] The melt viscosity of the thermoplastic elastomer composition of the present invention, as measured by a capillary rheometer at 190°C and a shear rate of 1000 / second, is preferably 50 Pa·s or less, more preferably 10 Pa·s or less, and even more preferably 1 Pa·s or less, from the viewpoint of coating properties. The melt viscosity of the thermoplastic elastomer composition is measured using a capillary rheometer by the method described in the examples below.

[0059] The thermoplastic elastomer composition of the present invention can produce a molded article that has resistance to compressive stress (also known as compression set). For example, the compression set after 24 hours at 23°C is preferably 50% or less, more preferably 45% or less, and even more preferably 40% or less. Furthermore, the compression set after 24 hours at 70°C is preferably 95% or less, more preferably 80% or less, and even more preferably 70% or less. The compression set can be measured according to the method described in the embodiments below.

[0060] The thermoplastic elastomer composition of the present invention has excellent sealing properties and can be used as various sealing materials for covering service holes in automobile doors, etc. For example, it can be used by hot-melt coating on components such as resin molded products, rubber molded products, or metal molded products. As shown in the examples described below, the thermoplastic elastomer composition of the present invention suppresses stickiness caused by oil bleeding, has no problems with fusion strength to polypropylene resin, and is a composition suitable for hot-melt coating. Therefore, the present invention also provides a method for manufacturing a composite, which includes a step of hot-melt coating on components such as resin molded products, rubber molded products, or metal molded products, and a composite obtained thereby. Furthermore, the thermoplastic elastomer composition of the present invention is not limited to the above embodiments and may be used as a thermoplastic elastomer molded article by various known molding methods, such as extrusion molding, press molding, injection molding, calendering, hollow molding, foam molding, and foam injection molding.

[0061] The hot-melt coating method for the thermoplastic elastomer composition of the present invention is not particularly limited and can use any generally available hot-melt coating apparatus. For example, a non-foaming bulk type hot-melt coating apparatus, such as Nordson's Bulk Melt (trade name), and a foam type hot-melt coating apparatus, such as Nordson's Foam Melt (trade name), can be used. In particular, the thermoplastic elastomer composition of the present invention teeth Because of its excellent gas solubility and foaming properties, it is suitable for use in so-called physical foaming hot melt processes, where nitrogen gas or carbon dioxide gas is dissolved in a heated and molten state, and then, upon coating the substrate, is released to atmospheric pressure, generating bubbles.

[0062] The thermoplastic elastomer composition of the present invention exhibits excellent heat-sealability to resin materials such as polypropylene resins and non-polar resins, and to styrene-based resins such as ABS resins, as well as to metal materials, making it suitable for use as a laminate with a resin substrate. For example, a laminate coated with foamed hot melt around the edge of a polypropylene molded plate becomes a lid with the foam as a sealing or cushioning layer, and by pressing and fixing it with screws, it prevents the intrusion of water, dust, etc. into a designated object. Furthermore, by releasing the screws, multiple opening and closing operations are possible, and because it is not sticky, opening operations are easy, and dust and dirt do not easily adhere to it, resulting in excellent sealing performance. The sealing material or cushioning material obtained from the thermoplastic elastomer composition of the present invention is designed based on a different concept from adhesives that aim to join multiple substrates to obtain an integrated structure.

[0063] The thermoplastic elastomer composition of the present invention is obtained by mixing raw materials containing component A, component B, and component C, and optionally component D and various additives, and solidifying them by cooling.

[0064] In this invention, "mixing" is not particularly limited as long as the various components are mixed well. The various components may be dissolved in an organic solvent and mixed, or they may be mixed by heating, melting, and kneading.

[0065] When heating, melting, and kneading, a general extruder or a double-arm batch mixer, such as a Banbury mixer (product name), can be used. From the viewpoint of productivity, which allows for continuous production with a shorter kneading time compared to a batch mixer, and a lower thermal history, it is preferable to use a multi-screw extruder with two or more screws. The extruder may be supplied by first mixing various components using a mixing device such as a Henschel mixer and supplying them from a single hopper, or by loading each component into two hoppers and supplying them quantitatively using screws below the hoppers, or by supplying solid raw materials from a hopper and supplying liquid raw materials during the kneading process in the extruder.

[0066] The product obtained by mixing the raw materials constituting the thermoplastic elastomer composition can be in the form of pellets, sheets, etc., depending on the application. For example, it can be heated, melted, and kneaded in an extruder to extrude into a strand, and then cut into cylindrical or rice-grain sized pellets of approximately 10 mm in diameter and 10 mm in length using a cutter while cooling in cold water or after cooling. In the hot melt coating process, the pellet shape is preferred because it allows for transport in piping lines, eliminates the need for a cutting process during weighing, improves convenience, enables automation, and shortens the melting time in the heated melt pot. Pellets refer to small tablet-like, cylindrical, or rice-grain granular forms. [Examples]

[0067] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way by these examples. The various physical properties of the raw materials used in the examples were measured by the following methods.

[0068] <Component A: Hydrogenated block copolymer> [Weight average molecular weight (Mw)] The weight-average molecular weight (Mw) was determined as the weight-average molecular weight in terms of polystyrene by gel permeation chromatography under the following measurement conditions. Measuring device Pump: PU-980, manufactured by JASCO (Japan Spectroscopic Co., Ltd.) • Column oven: Manufactured by Showa Denko Corporation, model AO-50 • Detector: Hitachi L-3300, RI (Differential Refractometer) detector. • Column type: One K-805L (8.0 x 300 mm) and one K-804L (8.0 x 300 mm) column from Showa Denko Corporation are used in series. Column temperature: 40°C • Guard column: KG (4.6 x 10 mm) • Eluent: Chloroform ·Eluent flow rate: 1.0mL / min • Sample concentration: Approximately 1 mg / mL • Sample solution filtration: Disposable polytetrafluoroethylene filter with a pore size of 0.45 μm. • Standard sample for calibration curve: Polystyrene manufactured by Showa Denko Corporation

[0069] [Composition of block copolymer] Proton NMR measurements were performed using a nuclear magnetic resonance spectrometer (BRUKER DPX-400, Germany) to determine the content of constituent units derived from styrene and / or styrene derivatives, for example, by quantifying the characteristic groups of styrene. The content of other monomer units can also be determined by proton NMR measurements.

[0070] [Meltmass Flow Rate (MFR)] The measurements were taken according to the method compliant with JIS K6921-2, under conditions of 230°C and a load of 21.2N.

[0071] [Content of side-chain alkyl groups in polymer block b] The block copolymers of each component A were dissolved in CDCl3 and the 13-carbon NMR spectra were measured (instrument: VNMRS500 (VARIAN), measurement temperature: 25°C). The content of the side-chain alkyl group was calculated from the ratio of the total peak area corresponding to the side-chain alkyl group to the peak area corresponding to the conjugated diene compound unit.

[0072] <Component B: Crystalline polyolefin resin>

[0073] [Melting point] The melting point was determined in accordance with ISO 11357-3, and the peak melting temperature was measured using a differential scanning calorimeter under a nitrogen atmosphere at a heating rate of 10°C / min.

[0074] [Heat of fusion] The heat of fusion was measured using a differential scanning calorimetry (DSC) analyzer, following the procedure described in JIS K 7122 (1987) for "measuring the heat of fusion after a certain heat treatment" (the heating and cooling rates in the conditioning of the test specimen were both set to 10°C / min).

[0075] [Meltmass Flow Rate (MFR)] The measurements were taken according to the method compliant with JIS K6921-2, under conditions of 230°C and a load of 21.2N.

[0076] <Ingredient C: Softener> [Kinematic viscosity] The viscosity was measured at a temperature of 40°C using a Brookfield-type rotational viscometer in accordance with JIS K 7117-1.

[0077] Examples 1-14 and Comparative Examples 1-11 (1) Preparation of thermoplastic elastomer composition (pellets) The raw materials were mixed together in the compositions shown in Tables 1-3 using a Kawata Super Mixer SMV-20Ba, heated and mixed at 60-80°C. The resulting powder was then supplied from the raw material supply hopper to the extruder and melted and kneaded under the following conditions. The time from the introduction of the raw materials into the input port until the black material was discharged from the extrusion die (kneading time) was 60-90 seconds in all cases. The molten resin extruded from the extruder was cooled in cold water and cut with a cutter into pieces approximately 3 mm in diameter and 3 mm thick to obtain pellets.

[0078] <Melting and mixing conditions> Extruder: Shibaura Machinery Co., Ltd., twin-screw compounding extruder, TEM-26SX-16 / 1V Cylinder temperature: The temperature near the hopper was set to 140°C, and up to the extruder outlet to 200°C. Screw rotation speed: 600 r / min

[0079] (2) Preparation of a 2mm thick sheet Pellets were injection molded under the following conditions to produce a sheet with dimensions of 125 mm in width, 125 mm in length, and 2 mm in thickness.

[0080] <Injection molding conditions> Injection molding machine: EC100SXII-4B (product name, manufactured by Toshiba Machine Co., Ltd.) Injection molding temperature: 160~200℃ Injection pressure: 120 MPa, Holding pressure: 10 MPa Injection time: 2sec Mold temperature: 40℃

[0081] [Table 1]

[0082] [Table 2]

[0083] [Table 3]

[0084] Details of the representative components used in the examples and comparative examples are as follows.

[0085] [Table 4]

[0086] [Table 5]

[0087] [Table 6] Ingredient c-1: (Product name "PW-90", manufactured by Idemitsu Kosan Co., Ltd.) Component c-2: (Product name "VIVA-B-FIX10227", manufactured by Hansen & Rosenthal, a branched alkane compound)

[0088] Furthermore, the following was used as an antioxidant for component D. Ingredient d-1: (Hindered phenol antioxidant, product name "Irganox 1010", manufactured by BASF Corporation) Ingredient d-2: (Phosphorus-based antioxidant, product name "Irgaphos 168", manufactured by BASF Corporation)

[0089] The following evaluations were performed using pellets or sheets of the thermoplastic elastomer compositions obtained in the examples and comparative examples. The results are shown in Tables 1 to 3.

[0090] [Hardness (HsA)] Three layers of 2mm thick sheets (total 6mm) were stacked and measured using a Type A durometer in accordance with JIS K 6253. The A hardness (value 15 seconds after the start of the test) was measured over a 15-second period. The measurements were performed in a room at 23°C and 50% humidity after a 1-day conditioning period. A smaller measured value, specifically a value of 90 or less, is preferable as it indicates good sealing properties.

[0091] [Melting viscosity of compositions measured by melt mass flow rate (MFR)] The measurements were taken in accordance with JIS K 7210-1, under test conditions of 190°C and a load of 21.2N.

[0092] [Melting viscosity of the composition measured with a Brookfield viscometer] Measurements were taken at 170°C, 190°C, and 210°C using a Brookfield-type rotational viscometer, in accordance with JIS K 7117-1. A metal test container filled with test pellets was placed in a melt pot set to the test temperature, and the pellets were melted while left undisturbed. Viscosity measurements were performed using a Brookfield viscometer (Eiko Seiki Co., Ltd., RV DV2T) with a spindle No. 27 (Eiko Seiki Co., Ltd., SC4-27). The spindle rotation speed was adjusted within the range of 0.1 to 100 r / min so that the torque value was within the range of 10 to 90% for measurement. A lower viscosity value indicates better hot-melt coating properties. If the composition did not melt at these temperatures, or if the viscosity of the melted material was too high to measure, it was evaluated as "unmeasurable".

[0093] [Melting viscosity of the composition measured by a capillary rheometer] The melt viscosity of the compositions obtained in each example and comparative example was measured using a capillary rheometer (Capillograph 1D, manufactured by Toyo Seiki Co., Ltd.) equipped with a die with a diameter of 1 mm and a length of 10 mm, under conditions of 190°C and a shear rate of 1000 / second.

[0094] [Compression set rate] A circular sheet measuring 29 mm in diameter and 2 mm in thickness was produced from a 2 mm thick sheet using a 29 mm diameter circular punching die. This sheet was inserted into a cylindrical mold measuring 12.5 mm in height and 29 mm in diameter. A hot press (Toho Machinery Co., Ltd., hydraulic molding machine TB-50-2) heated to 200°C was used to hot press for 5 minutes, followed by a cooling press for 5 minutes to produce a cylindrical test piece measuring 12.5 mm in thickness and 29 mm in diameter. In accordance with JIS K 6262, (1) the compression set rate under conditions of 25% compressibility, 23°C, and 24 hours, and (2) the compression set rate under conditions of 25% compressibility, 70°C, and 24 hours were measured. A smaller set rate indicates that the rebound force is maintained over a long period of time, which is preferable because it indicates good sealing performance over long periods. Specifically, when measured at 23°C, a set rate of 50% or less is preferable, and when measured at 70°C, a set rate of 95% or less is preferable.

[0095] [Oil bleed] A 2mm thick sheet was placed on high-quality paper and left undisturbed at 23°C for 168 hours. Afterward, the paper was visually inspected for any oil bleeding and evaluated according to the following criteria. It is preferable that no stains, i.e., oil bleeding, are observed. Oil bleeding is a phenomenon in which the softening agent component C seeps out over a long period of time, causing stickiness. In applications where multiple openings and closings are expected, it can lead to a decrease in sealing performance due to the accumulation of dust and dirt. <Evaluation Criteria> ○: No blemishes were found at all. △: Some stains were observed. ×: Obvious stains were observed.

[0096] [Fusing strength for non-polar resins (PP fusing strength)] A homopolypropylene (Sun Allomer, PM870A) injection molding plate (2 mm thick x 25 mm wide x 125 mm long) was prepared by dissolving the compositions obtained in each example and comparative example at 180°C and applying them to the plate. A 22.5 mm wide, 2.0 mm thick SEBS (Kraton, G1643) sheet was then placed on top, and a 100 g load was applied while cooling to create a fusion test specimen (composite molded body) with alternating gripping margins. A tensile shear test was performed at a tensile speed of 50 mm / min, and the maximum load per 25 mm width of the specimen was measured. From the viewpoint of substrate adhesion, a larger fusion force is preferable; for example, a force of 10 N / 25 m or more is preferable.

[0097] [Coating properties] The pellets obtained in each example and comparative example were loaded into a melt gun (Hakko MELTER806, 801-NL-S nozzle (discharge hole thickness 0.5 mm, width 5.5 mm)) and coated onto a polypropylene plate substrate. The surface properties of the coated material were visually inspected and evaluated according to the following evaluation criteria. From the viewpoint of discharge stability, the smoother the surface, the better the coating properties. <Evaluation Criteria> ○: A smooth-surfaced coating was obtained with stable dispensing. △: The discharge from the nozzle was pulsating, and there was a wavy surface on the coated material. ×: The molded product could not be obtained because it could not be extruded from the nozzle.

[0098] As shown in Tables 1-3, the compositions of Examples 1-14 all exhibit low melt viscosity on a Brookfield viscometer, indicating good hot-melt coating properties. Furthermore, these compositions all exhibit good compression set at 70°C, indicating that their sealing properties can be maintained for a long period when used as a sealant. In addition, there is no oil bleeding, and the surface of the sealant does not become sticky.

[0099] On the other hand, Comparative Example 1, which did not use component B, exhibited inferior compression set at 70°C compared to Example 1. Furthermore, Comparative Example 2, which did not use component C, had a higher melt viscosity and inferior hot-melt coating properties compared to Example 1. In addition, Comparative Example 2 had too high a melt viscosity to be hot-melt coated, and therefore, it was not possible to prepare a sample for a fusion strength test. Although it was not possible to measure the melt viscosity using a Brookfield viscometer, the results of measuring the melt viscosity using an MFR and a capillary rheometer as reference values ​​showed that Examples 1 to 14 had sufficiently lower viscosities. Furthermore, it was shown that the melt viscosity of the compositions of the present invention cannot be accurately and quantitatively evaluated using an MFR or a capillary rheometer.

[0100] Furthermore, Comparative Examples 3-8, which used a styrene-based elastomer with a low MFR instead of component A, had high melt viscosity and all exhibited poor hot-melt coating properties. In Comparative Example 9, where the amount of component C was increased, the melt viscosity decreased and the hot-melt coating properties showed an improvement, but the hardness decreased and bleed-out of the softener occurred. In addition, Comparative Example 10, which used a crystalline polyolefin resin whose melting point and heat of fusion did not satisfy the specified conditions, i.e., had low crystallinity and crystalline properties, showed a worse improvement in compression set compared to Examples 1, 11, and 12, and yielded results similar to Comparative Example 1. [Industrial applicability]

[0101] The thermoplastic elastomer composition of the present invention can be used in sealing gaskets, sheets, extruded films, tubes, etc., in the automotive, electrical and electronic products, packaging, and medical fields. The thermoplastic elastomer composition of the present invention is particularly suitable for use as a sealing material for covering service holes in automobile doors.

Claims

1. A thermoplastic elastomer composition comprising the following components A to C, wherein component A has a melt mass flow rate of 5 g / 10 min or more at 230°C and 21.2 N, and component B has a melting point of 130°C or higher and a heat of fusion (ΔH) of 20 J / g or more. Component A: Hydrogenated block copolymer containing polymer block a containing structural units derived from aromatic vinyl compounds and polymer block b containing structural units derived from conjugated diene compounds. Component B: Crystalline polyolefin resin Ingredient C: Softener

2. The thermoplastic elastomer composition according to claim 1, wherein component A comprises component A1, in which, among the structural units derived from the conjugated diene compound contained in the polymer block b, conjugated diene compound units having a side-chain alkyl group account for 40 mol% or more.

3. The thermoplastic elastomer composition according to claim 2, wherein the content of component A1 in component A is 50% by mass or more.

4. The thermoplastic elastomer composition according to claim 1, wherein the melt mass flow rate of component B at 230°C and 21.2N is 10 g / 10 min or more.

5. The thermoplastic elastomer composition according to claim 1, wherein the content of component B is 1 to 95 parts by mass per 100 parts by mass of component A.

6. The thermoplastic elastomer composition according to claim 1, wherein the content of component C is 5 to 400 parts by mass per 100 parts by mass of component A.

7. The thermoplastic elastomer composition according to claim 1, wherein the total content of component A, component B, and component C is 50 to 100% by mass.

8. The thermoplastic elastomer composition according to claim 1, wherein the melt viscosity measured by a Brookfield viscometer at 210°C is 100 Pa·s or less.

9. A thermoplastic elastomer composition according to claim 1, for forming a composite by heat-fusion bonding to a resin molded product, a rubber molded product, or a metal molded product.

10. A method for producing a composite, comprising the step of hot-melt coating a resin molded product, a rubber molded product, or a metal molded product with the thermoplastic elastomer composition described in any one of claims 1 to 9.

11. A composite comprising a layer formed from the thermoplastic elastomer composition described in any one of claims 1 to 9 on the surface of a resin molded product, a rubber molded product, or a metal molded product.

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