Thermoplastic elastomer composition and molded article thereof

Abstract

To provide a thermoplastic elastomer and a molded product having good sense of touch and designability while having sufficient abrasion resistance.SOLUTION: There is provided a thermoplastic elastomer composition which comprises (A) a hydrogenated product of a block copolymer having at least one each of a conjugated diene monomer unit block and a vinyl aromatic monomer unit block, (B) a copolymer having at least one hydrogenated copolymer block composed mainly of a conjugated diene monomer unit and a vinyl aromatic monomer unit, (C) an ethylene-α-olefin copolymer containing an ethylene unit and an α-olefin unit having 3 to 20 carbon atoms, (D) a propylene-based polymer, (E) a polyorganosiloxane and (E) a silylated polyolefin at a specific ratio, of which at least one part is crosslinked.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Olefin-based thermoplastic elastomers are lightweight, easily recyclable, and do not emit toxic gases when incinerated, and therefore, from the perspectives of energy conservation, resource conservation, and more recently, global environmental protection, their applications are expanding to automobile parts, industrial machinery parts, electrical and electronic parts, building materials, etc. Here, in the field of automobile parts, in addition to olefin-based polymers, thermoplastic elastomers containing hydrogenated products of block copolymers containing vinyl aromatic monomers such as styrene are also widely used.

[0003] For example, Patent Document 1 discloses a thermoplastic elastomer containing an ethylene-α-olefin copolymer, a hydrogenated product of a block copolymer having conjugated diene monomer units and vinyl aromatic monomer units, and an olefin resin.

[0004] Patent Document 2 also discloses a thermoplastic elastomer obtained by crosslinking a composition containing a polypropylene resin, a hydrogenated product of a block copolymer having conjugated diene monomer units and vinyl aromatic monomer units, a softener, and a polyorganosiloxane. Patent Document 2 also discloses that molded articles such as automotive interior materials can be produced by injection molding the thermoplastic elastomer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2010 / 067564 [Patent Document 2] WO2011 / 155571 Summary of the Invention [Problem to be solved by the invention]

[0006] Thermoplastic elastomers containing an olefin polymer and a hydrogenated product of a block copolymer containing a vinyl aromatic monomer such as styrene are widely used in fields such as automobile parts, and are also used in applications such as automobile interior materials.

[0007] Among automotive interior materials, interior skin materials are components that are likely to be touched by the driver and passengers of the vehicle. Therefore, interior skin materials are required to have sufficient abrasion resistance. Also, tactile sensations such as feel are required, and in particular, a smooth feel rather than a sticky feel is desired.

[0008] Therefore, an object of the present invention is to provide a thermoplastic elastomer and a molded article thereof that have sufficient abrasion resistance and also a good feel to the touch. [Means for solving the problem]

[0009] As a result of intensive investigations into solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by employing a thermoplastic elastomer containing a silylated polyolefin as a thermoplastic elastomer containing an olefin polymer and a hydrogenated product of a block copolymer containing a vinyl aromatic monomer such as styrene, and have thus completed the present invention.

[0010] That is, the present invention relates to the following [1] to [9]. [1] A thermoplastic elastomer composition containing the following components (A) to (F), which is at least partially crosslinked: Component (A): 100 parts by mass of a hydrogenated block copolymer having at least one conjugated diene monomer unit block and at least one vinyl aromatic monomer unit block; Component (B): 50 to 250 parts by mass of a copolymer having at least one hydrogenated copolymer block mainly composed of conjugated diene monomer units and vinyl aromatic monomer units; Component (C): 80 to 200 parts by mass of an ethylene-α-olefin copolymer containing ethylene units and α-olefin units having 3 to 20 carbon atoms; Component (D): 150 to 300 parts by mass of a propylene polymer; Component (E): 1 to 80 parts by mass of polyorganosiloxane; Component (F): 0.1 to 30 parts by mass of silylated polyolefin.

[0011] [2] The thermoplastic elastomer composition according to [1], which satisfies the following requirements (1) and (2): (1) The melt flow rate (MFR, 230°C, 1.2 kg load) measured in accordance with ASTM D1238 is 30 to 90 g / 10 min. (2) The surface hardness (JIS A hardness, instantaneous value) measured in accordance with JIS K7215 is 50 to 100.

[0012] [3] The thermoplastic elastomer composition according to [1] or [2], wherein the component (F) is a silylated polyethylene.

[0013] [4] The thermoplastic elastomer composition according to any one of [1] to [3], wherein the component (C) is an ethylene-1-octene copolymer.

[0014] [5] moreover, Component (G): Softener 200 to 500 parts by weight The thermoplastic elastomer composition according to any one of [1] to [4], comprising:

[0015] [6] The thermoplastic elastomer composition according to any one of [1] to [5], wherein the crosslinking is performed by an organic peroxide.

[0016] [7] An injection-molded article comprising the thermoplastic elastomer composition according to any one of [1] to [6]. [8] [7] A film or sheet made of the injection-molded article according to [7]. [9] [7] An automotive interior material comprising the injection-molded article according to [7]. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a thermoplastic elastomer and a molded article that have sufficient abrasion resistance, as well as good tactile feel and design properties. DETAILED DESCRIPTION OF THE INVENTION

[0018] Specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the object of the present invention.

[0019] In this specification, the term "polymerization" is used to encompass homopolymerization and copolymerization. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0020] [Thermoplastic elastomer composition] The thermoplastic elastomer composition according to the present invention contains the following components (A) to (F), which are at least partially crosslinked: Component (A): 100 parts by mass of a hydrogenated block copolymer having at least one conjugated diene monomer unit block and at least one vinyl aromatic monomer unit block; Component (B): 50 to 250 parts by mass of a copolymer having at least one hydrogenated copolymer block mainly composed of conjugated diene monomer units and vinyl aromatic monomer units; Component (C): 80 to 200 parts by mass of an ethylene-α-olefin copolymer containing ethylene units and α-olefin units having 3 to 20 carbon atoms; Component (D): 150 to 300 parts by mass of a propylene polymer; Component (E): 1 to 80 parts by mass of polyorganosiloxane; Component (F): 0.1 to 30 parts by mass of silylated polyolefin.

[0021] The thermoplastic elastomer composition according to the present invention will be described in detail below. <Component (A)> The thermoplastic elastomer composition according to the present invention contains a hydrogenated product (A) (hereinafter referred to as "component (A)") of a block copolymer having at least one conjugated diene monomer unit block and at least one vinyl aromatic monomer unit block. Here, "conjugated diene monomer unit" refers to a structural unit of a polymer resulting from the polymerization of a conjugated diene monomer, and has a molecular structure in which two carbon atoms of an olefin derived from the conjugated diene monomer serve as bonding sites. "Vinyl aromatic monomer unit" refers to a structural unit of a polymer resulting from the polymerization of a vinyl aromatic compound monomer, and has a molecular structure in which two carbon atoms of a substituted ethylene group derived from a substituted vinyl group serve as bonding sites.

[0022] The conjugated diene monomer is a diolefin having one pair of conjugated double bonds, and examples thereof include 1,3-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. 1,3-butadiene and isoprene are preferred. These may be used alone or in combination.

[0023] Examples of vinyl aromatic monomers include vinyl aromatic compounds such as styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N,N-dimethyl-p-aminoethylstyrene, and N,N-diethyl-p-aminoethylstyrene. These may be used alone or in combination. Among these, styrene is preferred from the viewpoint of economy.

[0024] The hydrogenated block copolymer of the present embodiment is a block copolymer of a conjugated diene monomer unit block and a B Nil aromaticThe hydrogenated product of this block copolymer is a block copolymer having at least one monomer unit block. B Nil aromatic When a polymer block consisting of a monomer unit is represented by "S" and a polymer block consisting of a conjugated diene monomer unit and / or a partially hydrogenated unit thereof is represented by "B", the polymer block can be represented by, for example, the following formula: S.B., S(BS) n1 (where n1 represents an integer of 1 to 3.) S(BSB) n2 (wherein n2 represents an integer of 1 to 2), (SB) n3 X (wherein 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).

[0025] Among these, star block copolymers with the "B" moiety as the bond center are preferred. Among these, linear block copolymers of SB type 2 (di-block), SBS type 3 (tri-block), and SBSB type 4 (tetra-block) are more preferred.

[0026] The content of vinyl aromatic monomer units in component (A) is preferably 20 to 80% by mass or more from the viewpoints of low-temperature properties, mechanical strength, and oil retention, and more preferably 30 to 70% by mass or more from the viewpoints of heat resistance and dispersibility. From the viewpoints of heat resistance, aging resistance, and weather resistance, component (A) preferably has 75 mol % or more of the unsaturated bonds contained in the conjugated diene units before hydrogenation hydrogenated, more preferably 85 mol % or more, and even more preferably 97 mol % or more.

[0027] It is preferable to use two or more types of component (A), i.e., two or more types of hydrogenated block copolymers, in combination. At least one of the components (A) has a vinyl aromatic monomer unit block (A1) content of 20% to 50% by mass, and at least one other component (A) has a vinyl aromatic monomer unit block content of more than 50% to 80% by mass. Component (A1) contributes to improving low-temperature properties, while component (A2) acts as a compatibilizer between the crosslinked rubber component and the olefin component, increasing the mechanical strength of the thermoplastic elastomer composition. Furthermore, because component (A) is difficult to crosslink, it can also retain a larger amount of the softener (component (G), described below, in the thermoplastic elastomer composition.

[0028] The hydrogenation catalyst is not particularly limited, and examples thereof include conventionally known (1) supported heterogeneous hydrogenation catalysts in which metals such as Ni, Pt, Pd, and Ru are supported on carbon, silica, alumina, diatomaceous earth, etc.; (2) so-called Ziegler-type hydrogenation catalysts that use transition metal salts such as organic acid salts or acetylacetone salts of Ni, Co, Fe, and Cr, etc., and reducing agents such as organoaluminum; and (3) homogeneous hydrogenation catalysts such as so-called organometallic complexes of organometallic compounds such as Ti, Ru, Rh, and Zr. Specific examples of hydrogenation catalysts that can be used include those described in Japanese Patent Publication Nos. 42-8704, 43-6636, 63-4841, 1-37970, 1-53851, and 2-9041. Preferred hydrogenation catalysts include mixtures of titanocene compounds and / or reducing organometallic compounds. As the titanocene compound, for example, the compounds described in JP-A-8-109219 can be used.

[0029] Examples of titanocene compounds include compounds having at least one ligand with a (substituted) cyclopentadienyl skeleton, an indenyl skeleton, or a fluorenyl skeleton, such as biscyclopentadienyltitanium dichloride and monopentamethylcyclopentadienyltitanium trichloride. Examples of reducing organometallic compounds include organic alkali metal compounds such as organolithium compounds, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds. Among these, a mixture of a titanocene compound and / or a reducing organometallic compound is preferred.

[0030] In the present embodiment, the polymerization method for the block copolymer of component (A) before hydrogenation is not particularly limited, and known methods can be used. Examples of the polymerization method include those described in Japanese Patent Publication Nos. 19286 / 1961, 17979 / 1968, 32415 / 1971, 36957 / 1974, 2423 / 1973, 4106 / 1973, 28925 / 1981, 166518 / 1984, and 186577 / 1985.

[0031] Component (A) may optionally contain a polar group, such as a hydroxyl group, a carboxyl group, a carbonyl group, a thiocarbonyl group, an acid halide group, an acid anhydride group, a thiocarboxylic acid group, an aldehyde group, a thioaldehyde group, a carboxylic acid ester group, an amide group, a sulfonic acid group, a sulfonate group, a phosphoric acid group, a phosphoric acid ester group, an amino group, an imino group, a nitrile group, a pyridyl group, a quinoline group, an epoxy group, a thioepoxy group, a sulfide group, an isocyanate group, an isothiocyanate group, a silicon halide group, an alkoxy silicon group, a tin halide group, a boronic acid group, a boron-containing group, a boronate salt group, an alkoxy tin group, or a phenyl tin group.

[0032] The weight-average molecular weight of component (A) is preferably 50,000 or more from the viewpoint of scratch resistance, and is preferably 400,000 or less from the viewpoint of molding flowability, and more preferably in the range of 50,000 to 300,000. A smaller molecular weight distribution (= weight-average molecular weight / number-average molecular weight) is preferable. The weight-average molecular weight can be determined by gel permeation chromatography (GPC) under the conditions described in the examples.

[0033] <Ingredient (B)> The thermoplastic elastomer composition according to the present invention contains a copolymer (B) (hereinafter referred to as "component (B)") having at least one hydrogenated copolymer block composed mainly of conjugated diene monomer units and vinyl aromatic monomer units. In this embodiment, the names of the monomer units constituting the copolymer are named according to the names of the monomers from which the monomer units are derived. For example, a "vinyl aromatic monomer unit" refers to a structural unit of a polymer resulting from the polymerization of a vinyl aromatic compound monomer, and has a molecular structure in which two carbon atoms of a substituted ethylene group derived from a substituted vinyl group serve as bonding sites. Furthermore, a "conjugated diene monomer unit" refers to a structural unit of a polymer resulting from the polymerization of a conjugated diene monomer, and has a molecular structure in which two carbon atoms of an olefin derived from the conjugated diene monomer serve as bonding sites.

[0034] In the present embodiment, "mainly composed of" means that the copolymer contains 60% by mass or more of the monomer unit, preferably 80% by mass or more of the monomer unit, more preferably 90% by mass or more, and even more preferably 95% by mass or more of the monomer unit.

[0035] In the present embodiment, examples of the vinyl aromatic monomer include vinyl aromatic compounds such as styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N,N-dimethyl-p-aminoethylstyrene, and N,N-diethyl-p-aminoethylstyrene. These may be used alone or in combination. Among these, styrene is preferred from the viewpoint of economy.

[0036] In the present embodiment, the conjugated diene is a diolefin having one pair of conjugated double bonds, and examples thereof include 1,3-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, 1,3-butadiene and isoprene are preferred, and from the viewpoint of mechanical strength, diolefins mainly composed of 1,3-butadiene are more preferred. These may be used alone or in combination of two or more.

[0037] In the present embodiment, the polymerization method for component (B) is not particularly limited, and known methods can be used. Examples of the polymerization method for component (B) include the methods described in JP-B Nos. 19286 / 1961, 17979 / 1968, 32415 / 1971, 36957 / 1974, 2423 / 1973, 4106 / 1973, 28925 / 1981, 166518 / 1984, and 186577 / 1985.

[0038] The mass ratio of the conjugated diene monomer units to the vinyl aromatic monomer units in the hydrogenated copolymer block in component (B) is not particularly limited, but is preferably 90:10 to 10:90, more preferably 80:20 to 20:80, and even more preferably 70:30 to 30:70.

[0039] From the viewpoints of scratch resistance, heat resistance, and dispersibility, component (B) preferably contains 30% by mass or more, more preferably 40% by mass or more, and even more preferably 45% by mass or more, of vinyl aromatic monomer units, and from the viewpoint of flexibility, it preferably contains 90% by mass or less, and preferably 80% by mass or less.

[0040] Component (B) further contains preferably 5% by mass or more of blocks mainly composed of vinyl aromatic monomer units from the viewpoint of mechanical strength, and 50% by mass or less from the viewpoint of flexibility, more preferably 10% by mass or more and 35% by mass or less, and even more preferably 13% by mass or more and 30% by mass or less.

[0041] The content of the vinyl aromatic compound polymer block in the copolymer of component (B) is defined by the following formula using the mass of the vinyl aromatic compound polymer block (excluding vinyl aromatic compound polymers having an average degree of polymerization of 30 or less) obtained by a method of oxidatively decomposing the 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); hereinafter, also referred to as the "osmic tetroxide acid method"). Content of vinyl aromatic compound polymer block (mass%)=(mass of vinyl aromatic compound polymer block in copolymer before hydrogenation / mass of copolymer before hydrogenation)×100

[0042] When component (B) contains multiple polymer blocks, the molecular weights, compositions, and other structures of the polymer blocks may be the same or different. Component (B) may contain a hydrogenated copolymer block primarily composed of conjugated diene units and vinyl aromatic monomer units, and a hydrogenated copolymer block primarily composed of conjugated diene monomer units. The boundaries and extreme ends of the polymer blocks do not necessarily need to be clearly distinguished. The distribution of the vinyl aromatic monomer units in each polymer block is not limited as long as it is within the range of the vinyl aromatic compound content described above, and may be uniform, tapered, stepped, convex, or concave. Furthermore, each polymer block may contain crystalline portions.

[0043] The distribution of vinyl units in the conjugated diene units in each polymer block is not particularly limited, and the distribution may be biased. Methods for controlling the distribution of vinyl units include adding a vinylating agent during polymerization and changing the temperature during polymerization. Furthermore, the distribution of hydrogenation rates of conjugated diene units may be biased. Methods for controlling the distribution of hydrogenation rates include changing the distribution of vinyl units and utilizing the difference in the hydrogenation rates between isoprene units and butadiene units by copolymerizing isoprene and butadiene and then hydrogenating them using a catalyst described below.

[0044] From the viewpoints of heat resistance, aging resistance, and weather resistance, component (B) preferably has 75 mol % or more, more preferably 85 mol % or more, and even more preferably 97 mol % or more of the unsaturated bonds contained in the conjugated diene units before hydrogenation hydrogenated.

[0045] The hydrogenation catalyst is not particularly limited, and examples thereof include the same hydrogenation catalysts as those usable in the production of component (A), such as the supported heterogeneous hydrogenation catalysts, Ziegler-type hydrogenation catalysts, and homogeneous hydrogenation catalysts such as organometallic complexes. Preferred hydrogenation catalysts include mixtures of titanocene compounds and / or reductive organometallic compounds. Examples of the titanocene compound and the reductive organometallic compound include the same titanocene compounds and reductive organometallic compounds as those usable in the production of component (A), respectively.

[0046] The peak temperature of the loss tangent (tan δ) of component (B) is not particularly limited, but from the viewpoint of flexibility, it is preferable that there be at least one peak at 40° C. or less, and from the viewpoint of abrasion resistance, it is preferable that there be at least one peak at −25° C. or more. This loss tangent can be measured using the viscoelasticity measuring device described in the examples below.

[0047] The vinyl content in the conjugated diene contained in component (B) before hydrogenation is preferably 5 mol or more from the viewpoints of flexibility and scratch resistance, and is preferably 70 mol% or less from the viewpoints of manufacturability, high elongation at break, and scratch resistance. The vinyl content in the conjugated diene is more preferably in the range of 10 mol% to 50 mol%, even more preferably in the range of 10 mol% to 30 mol%, and even more preferably in the range of 10 mol% to 25 mol%.

[0048] The vinyl content refers to the proportion of 1,2-bonds and 3,4-bonds among the 1,2-bonds, 3,4-bonds and 1,4-bonds incorporated in the conjugated diene before hydrogenation. The amount of vinyl bonds can be measured by nuclear magnetic resonance spectroscopy (NMR).

[0049] Component (B) may optionally contain a polar group, such as a hydroxyl group, a carboxyl group, a carbonyl group, a thiocarbonyl group, an acid halide group, an acid anhydride group, a thiocarboxylic acid group, an aldehyde group, a thioaldehyde group, a carboxylic acid ester group, an amide group, a sulfonic acid group, a sulfonate group, a phosphoric acid group, a phosphoric acid ester group, an amino group, an imino group, a nitrile group, a pyridyl group, a quinoline group, an epoxy group, a thioepoxy group, a sulfide group, an isocyanate group, an isothiocyanate group, a silicon halide group, an alkoxy silicon group, a tin halide group, a boronic acid group, a boron-containing group, a boronate salt group, an alkoxy tin group, or a phenyl tin group.

[0050] The weight-average molecular weight of component (B) is preferably 50,000 or more from the viewpoint of scratch resistance, and is preferably 400,000 or less from the viewpoint of molding flowability, more preferably in the range of 50,000 to 300,000, and even more preferably in the range of 100,000 to 250,000. A smaller molecular weight distribution (weight-average molecular weight / number-average molecular weight) is preferable. The weight-average molecular weight can be determined by gel permeation chromatography (GPC) under the conditions described in the examples.

[0051] The content of component (B) is 50 to 250 parts by mass, preferably 80 to 230 parts by mass, more preferably 100 to 200 parts by mass, and even more preferably 130 to 180 parts by mass, per 100 parts by mass of component (A) (from the viewpoint of suppressing changes in appearance due to wear and obtaining a good feel).

[0052] <Ingredient (C)> The thermoplastic elastomer composition according to the present invention contains an ethylene-α-olefin copolymer (C) (hereinafter referred to as "component (C)") containing ethylene units and α-olefin units having 3 to 20 carbon atoms. Component (C) can be obtained by copolymerizing at least ethylene and an α-olefin having 3 to 20 carbon atoms. Examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene. Among these, α-olefins having 3 to 12 carbon atoms are preferred, with propylene, 1-butene, and 1-octene being more preferred, from the viewpoint of imparting flexibility. In one preferred embodiment of the present invention, component (C) is an ethylene-1-octene copolymer.

[0053] Component (C) can be copolymerized with a monomer having an unsaturated bond, if necessary. Examples of the monomer having an unsaturated bond include conjugated diolefins such as butadiene and isoprene, non-conjugated diolefins such as 1,4-hexadiene, cyclic diene compounds such as dicyclopentadiene and norbornene derivatives, and acetylenes. Among these, ethylidene norbornene (ENB) and dicyclopentadiene (DCP) are more preferred from the viewpoint of flexibility.

[0054] The Mooney viscosity (ML) of component (C) measured at 100° C. is not particularly limited, but from the viewpoints of crosslinking reactivity and flexibility of the composition, it is preferably 20 to 150 ML, more preferably 50 to 120 ML.

[0055] It is preferable to use a metallocene catalyst for producing component (C). Metallocene catalysts generally consist of a cyclopentadienyl derivative of a Group IV metal such as titanium or zirconium and a cocatalyst. There are no particular limitations on the metallocene catalyst, and any known catalyst can be used. Metallocene catalysts are not only highly active as polymerization catalysts, but also, compared with Ziegler catalysts, can narrow the molecular weight distribution of the resulting copolymer and can uniformly distribute the α-olefin having 3 to 20 carbon atoms, which is the comonomer, in the copolymer.

[0056] The copolymerization ratio of the α-olefin in component (C) is not particularly limited, but is preferably 1 to 60 mass%, more preferably 10 to 50 mass%, and even more preferably 20 to 45 mass%. By setting the copolymerization ratio of the α-olefin within the above range, the mechanical strength (tensile strength, etc.) and flexibility of the thermoplastic elastomer composition can be further improved.

[0057] The density of component (C) is not particularly limited, but is preferably 0.8 to 0.9 g / cm 3 By using component (C) having a density in this range, a thermoplastic elastomer composition with even better flexibility can be obtained.

[0058] The structure of component (C) is not particularly limited, but it is preferable that it has long chain branches. Here, long chain branches refer to branches with three or more carbon atoms. The presence of long chain branches makes it possible to reduce the density compared to the copolymerization ratio (mass%) of the copolymerized α-olefin without reducing mechanical strength. As a result, a thermoplastic elastomer composition with lower density and higher strength can be obtained. The olefin elastomer having long chain branches is not particularly limited, and for example, the olefin elastomers described in U.S. Pat. No. 5,278,272 can be used.

[0059] Component (C) preferably has a melting point peak in differential scanning calorimetry (DSC) in a temperature range above room temperature. Component (C) having a melting point peak in a temperature range above room temperature can provide a thermoplastic elastomer that has excellent shape stability in a temperature range below the melting point, is easy to handle, and is less sticky.

[0060] The melt flow rate (MFR) of component (C) is preferably in the range of 0.01 to 100 g / 10 min (190°C, 2.16 kg load (0.212 Pa), conforming to ASTM D1238), and more preferably in the range of 0.2 to 10 g / 10 min. By setting the MFR within the above range, a thermoplastic elastomer with an excellent balance of fluidity and mechanical strength can be obtained.

[0061] From the viewpoint of a good balance between molding flowability and flexibility, the content of component (C) is 80 to 200 parts by mass, preferably 100 to 180 parts by mass, more preferably 110 to 160 parts by mass, and even more preferably 120 to 150 parts by mass, per 100 parts by mass of component (A).

[0062] <Ingredient (D)> The thermoplastic elastomer composition according to the present invention contains a propylene polymer (D) (hereinafter referred to as "component (D)"). The propylene polymer referred to here refers to a propylene homopolymer (also referred to as homopolypropylene) and a propylene copolymer obtained by copolymerizing propylene with another monomer copolymerizable with propylene. From the viewpoint of mechanical properties, the propylene polymer (D) is preferably a propylene homopolymer, but it is also possible to use a propylene copolymer, for example, a copolymer of propylene and ethylene.

[0063] Specific examples of the propylene copolymer include copolymers of propylene with other α-olefins such as ethylene, 1-butene, 1-pentene, 1-hexene, etc. The structure of the propylene copolymer is not particularly limited, and may be either a block copolymer or a random copolymer.

[0064] In this embodiment, the melt flow rate (MFR) of the propylene polymer (D) contained in the composition before crosslinking at 230°C under a load of 2.16 kg is not particularly limited, but is preferably 0.2 to 5 g / 10 min. By setting the MFR to 5 g / 10 min or less, the thermoplastic elastomer composition and its molded article can have better heat resistance and mechanical properties, while by setting the MFR to 0.2 g / 10 min or more, the molding fluidity can be improved, imparting excellent molding processability to the molded article. In particular, from the viewpoint of the balance between fluidity and mechanical strength after the crosslinking reaction, the MFR of component (D) is more preferably 0.2 to 3 g / 10 min. The MFR here can be measured in accordance with ASTM D1238.

[0065] The propylene polymer (D) contained in the composition before crosslinking has a weight average molecular weight of 5.0×10 in terms of polystyrene as measured by gel permeation chromatography (GPC) using o-dichlorobenzene as a solvent. 5 ~1.0×10 6 Preferably, it is 5.0 × 10 5 ~9.0×10 5 It is more preferable that the weight average molecular weight of component (D) before crosslinking is 5.0 × 10 5 By adjusting the temperature to 1.0×10 or more, the thermoplastic elastomer composition and its molded article can have better heat resistance and mechanical properties. 6 By setting the content below, the molding flowability becomes better, and excellent molding processability can be imparted.

[0066] The propylene polymer (D) contained in the thermoplastic elastomer composition of the present embodiment after crosslinking has a weight average molecular weight of 5.0×10 in terms of polystyrene, as measured by GPC using o-dichlorobenzene as a solvent. 4 ~2.0×10 5 Preferably, it is 7.0 × 10 4 ~1.5×10 5By setting the weight average molecular weight of component (D) after crosslinking within the above range, the resin exhibits even more excellent properties in molding flowability, reproducibility of drawing, heat resistance, and mechanical properties.

[0067] From the viewpoint of a good balance between low-temperature properties and mechanical properties, the content of component (D) is 150 to 300 parts by mass, preferably 170 to 280 parts by mass, more preferably 200 to 270 parts by mass, and even more preferably 210 to 260 parts by mass, per 100 parts by mass of component (A).

[0068] <Ingredient (E)> The thermoplastic elastomer composition according to the present invention contains a polyorganosiloxane (E) (hereinafter referred to as "component (E)"). The structure of the polyorganosiloxane is not particularly limited, but from the viewpoints of abrasion resistance and feel, it is preferable that the polyorganosiloxane has a linear, branched, or crosslinked polymer structure.

[0069] The polyorganosiloxane used as component (E) is not particularly limited, and known ones can be used.Preferred polyorganosiloxanes are polymers containing siloxane units having substituents such as alkyl groups, vinyl groups, and aryl groups, and among these, polyorganosiloxanes having alkyl groups are particularly preferred, and polyorganosiloxanes having methyl groups are more preferred.

[0070] Specific examples of polyorganosiloxanes having a methyl group include polydimethylsiloxane, polymethylphenylsiloxane, polymethylhydrogensiloxane, etc. Among these, polydimethylsiloxane is preferred.

[0071] The kinematic viscosity of component (E) is not particularly limited, but from the viewpoint of abrasion resistance, the kinematic viscosity (25°C) specified in JIS Z8803 is preferably 5,000 centistokes (cSt) or more. Furthermore, from the viewpoints of tending to improve the dispersibility of component (E) in the thermoplastic elastomer composition of this embodiment, leading to excellent appearance and further improved quality stability during melt extrusion, the kinematic viscosity of component (E) is preferably less than 2,000,000 cSt. The kinematic viscosity of component (E) is more preferably 10,000 cSt or more and less than 1,500,000 cSt, and even more preferably 50,000 cSt or more and less than 1,200,000 cSt.

[0072] From the viewpoint of suppressing bleeding during molding while ensuring good abrasion resistance, the content of component (E) is 1 to 80 parts by mass, preferably 10 to 60 parts by mass, more preferably 15 to 50 parts by mass, and even more preferably 20 to 40 parts by mass, per 100 parts by mass of component (A).

[0073] <Component (F)> The thermoplastic elastomer composition according to the present invention contains a silylated polyolefin (F) (hereinafter referred to as "component (F)"). The silylated polyolefin used as component (F) in the present invention is not particularly limited as long as the object and effect of the present invention are not impaired. Examples thereof include the silylated polyolefins described in JP 2015-189088 A.

[0074] That is, in an exemplary and preferred embodiment of the present invention, component (F) is a silylated polyolefin obtained by reacting a silicon-containing compound containing a structural unit represented by the following formula (1) with a vinyl group-containing compound having a number average molecular weight of 100 or more and 500,000 or less as determined by gel permeation chromatography (GPC) (excluding the case where the silicon-containing compound has two or more SiH groups per molecule and the vinyl group-containing compound has an average of 2.0 or more vinyl groups per molecule).

[0075] -Si(R 1 )HY 1- (1) In the formula (1), R 1 is a hydrogen atom, a halogen atom or a hydrocarbon group, and Y 1 is O, S or NR 30 (R 30 is a hydrogen atom or a hydrocarbon group).

[0076] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, and an aryl group. Examples of the alkyl group include linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, hexyl, 2-ethylhexyl, octyl, decyl, and octadecyl groups; cycloalkyl groups such as cyclopentyl, cyclohexyl, and norbornyl groups; and arylalkyl groups such as benzyl, phenylethyl, and phenylpropyl groups.

[0077] Examples of the alkenyl group include a vinyl group, a propenyl group, and a cyclohexenyl group. Examples of the aryl group include a phenyl group, a tolyl group, a dimethylphenyl group, a trimethylphenyl group, an ethylphenyl group, a propylphenyl group, a biphenyl group, a naphthyl group, a methylnaphthyl group, an anthryl group, and a phenanthryl group.

[0078] The hydrocarbon groups may also contain one or more heteroatoms, specifically, groups in which at least one hydrogen atom of these groups has been substituted with a group containing a halogen atom, oxygen, nitrogen, silicon, phosphorus, or sulfur.

[0079] In the present invention, the silicon-containing compound is preferably a silicon-containing compound having two or more SiH groups, and examples thereof include methylhydrogenpolysiloxanes represented by the following formula (2), and compounds in which some or all of the methyl groups in the following formula (2) have been substituted with ethyl groups, propyl groups, phenyl groups, trifluoropropyl groups, etc.

[0080] HSi(CH3)2O-(-Si(CH3)2-O-) i -Si(CH3)2H(2) (In the above formula (2), i is an integer of 1 or more, and the upper limit is, for example, 1000, preferably 300, and more preferably 50.)

[0081] More specifically, such compounds include, but are not limited to, the compounds shown below. HSi(CH3)2O-(-Si(CH3)2-O-)5-Si(CH3)2H HSi(CH3)2O-(-Si(CH3)2-O-)8-Si(CH3)2H HSi(CH3)2O-(-Si(CH3)2-O-) 18 -Si(CH3)2H HSi(CH3)2O-(-Si(CH3)2-O-) 80 -Si(CH3)2H HSi(CH3)2O-(-Si(CH3)2-O-) 230 -Si(CH3)2H

[0082] On the other hand, examples of the vinyl group-containing compound include compounds having a structure represented by the following formula (3): A-CH=CH2(3) (In formula (3), A is a polymer chain containing a structure derived from an α-olefin having 2 to 50 carbon atoms.)

[0083] In the above (3), the part A of the vinyl group-containing compound is preferably an ethylene polymer chain, a propylene polymer chain, or a copolymer chain of two or more olefins selected from the group consisting of α-olefins having 2 to 50 carbon atoms. The α-olefin is preferably an α-olefin having 2 to 20 carbon atoms.

[0084] In a preferred embodiment, A of the vinyl group-containing compound represented by the above formula (3) is a polymer chain composed solely of an α-olefin having 2 to 50 carbon atoms. More preferably, A of the vinyl group-containing compound is a polymer chain composed solely of an α-olefin having 2 to 20 carbon atoms. Even more preferably, A of the vinyl group-containing compound is an ethylene homopolymer chain, a propylene homopolymer chain, or an ethylene-α-olefin copolymer chain having 3 to 20 carbon atoms.

[0085] The vinyl group-containing compound represented by the formula (3) is preferably an ethylene-α-olefin copolymer containing 81 to 100 mol% of ethylene-derived structural units and 0 to 19 mol% of C3 to C20 α-olefin-derived structural units. More preferably, it is an ethylene-α-olefin copolymer containing 90 to 100 mol% of ethylene-derived structural units and 0 to 10 mol% of C3 to C20 α-olefin-derived structural units. It is particularly preferred that the ethylene-derived structural units are 100 mol%.

[0086] In one particularly preferred embodiment of the present invention, A of the vinyl group-containing compound is an ethylene polymer chain such as an ethylene homopolymer chain. In other words, the silylated polyolefin used as component (F) in the present invention is preferably a silylated polyethylene.

[0087] Furthermore, the vinyl group-containing compound represented by the above formula (3) preferably has a molecular weight distribution (ratio of weight average molecular weight to number average molecular weight, Mw / Mn) measured by gel permeation chromatography (GPC) in the range of 1.1 to 3.0.

[0088] The vinyl group-containing compound represented by the formula (3) preferably has a number average molecular weight (Mn) in the range of 100 to 500,000, more preferably 500 to 50,000, and even more preferably 700 to 10,000.

[0089] The vinyl group-containing compound represented by the formula (3) preferably has a melting point of 70°C or higher and 130°C or lower. More preferably, the vinyl group of the vinyl group-containing compound represented by the above formula (3) is present at the terminal of the main chain, and even more preferably, the vinyl group is present only at the terminal of the main chain.

[0090] The presence of a vinyl group at the end of the main chain can be confirmed by, for example, 13 C-NMR, 1 This can be achieved by using H-NMR. For example, if A is an ethylene homopolymer, 13 No tertiary carbon is detected by C-NMR, and 1 One method for confirming this is by detecting the hydrogen atoms of the vinyl group using H-NMR. 1 Even with H-NMR alone, the structure can be confirmed by assigning the peaks of each detected proton. For example, in the compound synthesized in Synthesis Example 1 described below, the peak at a chemical shift of 0.81 ppm, with a proton integral value of 3, is assigned to a methyl group at one end, the peak at a chemical shift of 1.10-1.45 ppm is assigned to a methylene group in the main chain, the peak at a chemical shift of 1.93 ppm, with a proton integral value of 2, is assigned to a methylene group adjacent to the terminal vinyl group, and the peaks at 4.80, 4.86, and 5.60-5.72 ppm, with proton integral values ​​of 1, are assigned to terminal vinyl groups. Since there are no other peaks of unknown assignment, it can be confirmed that A is an ethylene homopolymer and has a structure containing vinyl groups only at the ends. Alternatively, as another method, it can be determined that the hydrogen of the vinyl group present at the end of the main chain is more likely to be present than the hydrogen of the vinyl group present in the side chain. 1 Taking advantage of the short relaxation time in H-NMR measurement, it is possible to determine the relaxation time by, for example, comparing the relaxation time with that of hydrogen of the vinyl group of a polymer having a vinyl group in the side chain.

[0091] vinyl groups in the side chains 1 In some cases, it can be distinguished by taking advantage of the fact that the chemical shift in H-NMR is shifted downfield compared to the vinyl group present at the terminal. Furthermore, when the vinyl group-containing compound represented by the above formula (3) contains a vinyl group only at the terminal of the main chain, 1The terminal unsaturation rate (VE) calculated by H-NMR is preferably 60 mol % or more and 100 mol % or less. 1 The percentage of terminal unsaturation calculated by H-NMR is 80 mol % or more and 99.5 mol % or less, more preferably 90 mol % or more and 99 mol % or less.

[0092] The vinyl group-containing compound represented by the above formula (3) can be obtained by polymerizing or copolymerizing at least one olefin having 2 to 50 carbon atoms using a catalyst (B) comprising a transition metal compound (A) represented by the following formula (I), formula (II), or formula (III) and at least one compound selected from the group consisting of (B-1) an organometallic compound, (B-2) an organoaluminum oxy compound, and (B-3) a compound that reacts with the transition metal compound (A) to form an ion pair.

[0093] A transition metal compound represented by formula (I)

[0094] [ka]

[0095] (In the above formula (I), M represents a transition metal atom of Groups 4 to 5 of the periodic table. m represents an integer of 1 to 4. R 51 is a straight chain hydrocarbon group having 1 to 5 carbon atoms (C n' H 2n'+1 ,n ' = 1 to 5) or hydrogen atom. 52 ~R 56 may be the same or different and represent a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residue, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group, or a tin-containing group, and two or more of these may be linked to each other to form a ring. 52 ~R 56Two of the groups represented by the formula (I) may be linked together. n is a number that satisfies the valence of M, and X represents a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, a boron-containing group, an aluminum-containing group, a phosphorus-containing group, a halogen-containing group, a heterocyclic compound residue, a silicon-containing group, a germanium-containing group, or a tin-containing group. When n is 2 or more, the multiple groups represented by X may be the same or different, and the multiple groups represented by X may be bonded to each other to form a ring.

[0096] A transition metal compound represented by formula (II)

[0097] [ka]

[0098] (In the above formula (II), M represents a transition metal atom of Groups 4 to 5 of the periodic table. m represents an integer of 1 to 4. R 61 R represents a 3- to 5-membered alicyclic hydrocarbon group which may have one or more substituents. 62 ~R 66 may be the same or different and represent a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residue, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group, or a tin-containing group, and two or more of these may be linked to each other to form a ring. 62 ~R 66 Two of the groups represented by the formula (I) may be linked together. n is a number that satisfies the valence of M, and X represents a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, a boron-containing group, an aluminum-containing group, a phosphorus-containing group, a halogen-containing group, a heterocyclic compound residue, a silicon-containing group, a germanium-containing group, or a tin-containing group. When n is 2 or more, the multiple groups represented by X may be the same or different, and the multiple groups represented by X may be bonded to each other to form a ring.

[0099] A transition metal compound represented by formula (III)

[0100] [ka]

[0101] (In the above formula (III), M represents a transition metal atom of Groups 4 to 5 of the periodic table. m represents an integer of 1 to 4. R 71 R represents a bicyclic hydrocarbon group having 4 to 20 carbon atoms and sharing at least one carbon atom, which may have one or more substituents. 72 ~R 76 may be the same or different and represent a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residue, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group, or a tin-containing group, and two or more of these may be linked to each other to form a ring. 72 ~R 76 Two of the groups represented by the formula (I) may be linked together. n is a number that satisfies the valence of M, and X represents a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, a boron-containing group, an aluminum-containing group, a phosphorus-containing group, a halogen-containing group, a heterocyclic compound residue, a silicon-containing group, a germanium-containing group, or a tin-containing group. When n is 2 or more, the multiple groups represented by X may be the same or different, and the multiple groups represented by X may be bonded to each other to form a ring. Furthermore, when A is composed only of ethylene-derived structural units, or when A is composed only of propylene-derived structural units, it can also be produced by the following method.

[0102] (Polyolefin with ethylene homopolymer chains) (E1) Polyolefin polymer chains having ethylene homopolymer chains can also be produced, for example, by the following method.

[0103] (a) A polymerization method using a transition metal compound having a salicylaldimine ligand as a polymerization catalyst, as disclosed in JP-A Nos. 2000-239312, 2001-2731, and 2003-73412.

[0104] (b) A polymerization method using a titanium-based catalyst comprising a titanium compound and an organoaluminum compound. (c) A polymerization method using a vanadium catalyst comprising a vanadium compound and an organoaluminum compound. (d) A polymerization method using a metallocene catalyst comprising a metallocene compound such as zirconocene and an organoaluminum oxy compound (aluminoxane).

[0105] (Polyolefin with propylene homopolymer chains) (E2) Polyolefin polymer chains having propylene homopolymer chains can also be produced, for example, by the following method.

[0106] (a) A method of polymerizing propylene in the presence of a supported titanium catalyst, such as a magnesium-supported titanium catalyst or a metallocene catalyst, as disclosed in JP-A-2004-262993.

[0107] (b) A method of polymerizing propylene in the presence of a metallocene catalyst comprising a compound that reacts with a transition metal in a metal compound to form an ionic complex, an organoaluminum compound, and an aluminoxane, as disclosed in JP-A-2000-191862, JP-A-2002-097325, etc.

[0108] The silylated polyolefin used in the present embodiment may be one produced by any method, but is preferably a silylated polyolefin or a derivative thereof, or a mixture thereof, obtained by sequentially carrying out the following [Step 1] and [Step 2].

[0109] [Step 1] a step of mixing and stirring a silicon-containing compound and a transition metal halide, and filtering the resulting suspension to obtain a transition metal catalyst composition (C) as a filtrate; [Step 2] A step of reacting a vinyl group-containing compound with a silicon-containing compound in the presence of the transition metal catalyst composition (C) obtained in [Step 1] above (excluding the case where the silicon-containing compound has two or more SiH groups per molecule and the vinyl group-containing compound has an average of 2.0 or more vinyl groups per molecule).

[0110] Specific examples of the transition metal halide include platinum dichloride, platinum tetrachloride, platinum dibromide, platinum diiodide, rhodium trichloride, rhodium tribromide, rhodium triiodide, iridium trichloride, iridium tetrachloride, iridium tribromide, iridium triiodide, ruthenium trichloride, ruthenium tribromide, ruthenium triiodide, osmium trichloride, osmium tribromide, osmium triiodide, nickel dichloride, nickel difluoride, nickel dibromide, nickel diiodide, palladium dichloride, palladium dibromide, palladium diiodide.Among these, platinum dichloride, palladium dichloride, ruthenium trichloride, rhodium trichloride, iridium trichloride are preferred, and platinum dichloride is most preferred.

[0111] The amounts of the silicon-containing compound and transition metal halide used in [Step 1] are not particularly limited as long as the amount of the silicon-containing compound is 1 equivalent or more relative to the transition metal halide, but are preferably 2 equivalents or more. If the amount of the silicon-containing compound is too small, the stirring required for preparing the transition metal catalyst composition (C) may become difficult.

[0112] On the other hand, the silicon-containing compound used in [Step 2] may be different from the silicon-containing compound used in [Step 1], but is preferably the same as the silicon-containing compound used in [Step 1].

[0113] The quantitative ratio of the vinyl group-containing compound to the silicon-containing compound when reacting them varies depending on the purpose, but is typically in the range of 0.01 to 10 equivalents, preferably 0.1 to 2 equivalents, as the equivalent ratio of the vinyl group in the vinyl group-containing compound to the Si-H bond in the silicon-containing compound. The amount of silicon-containing compound used here is the sum of the portion contained in the transition metal catalyst composition (C) used in [Step 1] and the portion newly added in [Step 2]. If the entire amount of silicon-containing compound required in [Step 1] is used, [Step 2] can be performed without adding any additional silicon-containing compound.

[0114] The reaction between the vinyl group-containing compound and the silicon-containing compound is carried out in the presence of the transition metal catalyst composition (C) prepared in [Step 1]. The ratio of the transition metal catalyst composition (C) to the vinyl group-containing compound is 10:1 as the equivalent ratio of the vinyl group in the vinyl group-containing compound to the transition metal in the transition metal catalyst composition (C). -10 ~10 -1 The range is 10 times the equivalent amount, preferably 10 -7 ~10 -3 It is in the range of equivalent times.

[0115] The reaction method for the reaction of the vinyl group-containing compound with the silicon-containing compound is not limited as long as the final reaction is achieved, but may be, for example, as follows: The vinyl group-containing compound is placed in a reaction vessel, and the silicon-containing compound and transition metal catalyst composition (C) are placed in a nitrogen atmosphere. The reaction vessel is placed in an oil bath whose internal temperature has been previously raised to above the melting point of the vinyl group-containing compound, and the mixture is stirred. After the reaction, the oil bath is removed and the mixture is cooled to room temperature. The resulting reaction mixture is then placed in a poor solvent such as methanol or acetone and stirred for 2 hours. The resulting solid is then filtered, washed with the poor solvent, and dried at 60°C under reduced pressure of 2 hPa or less to obtain the target product.

[0116] In the present invention, when the silylated polyolefin used as component (F) is, for example, a methylhydrogenpolysiloxane represented by formula (2) above as the silicon-containing compound and a compound having the structure represented by formula (3) above as the vinyl-group-containing compound, the portion derived from the vinyl-group-containing compound is referred to as the "polyolefin chain" and the portion derived from the silicon-containing compound is referred to as the "silicon-containing compound chain," and is thought to have a structure similar to that of a block copolymer in which (polyolefin chain)-(silicon-containing compound chain)-(polyolefin chain) are bonded in this order. Specifically, it is thought to have a structure represented by formula (4) below: A-CH2-CH2-Si(CH3)2O-(-Si(CH3)2-O-) i -Si(CH3)2-CH2-CH2-A (4) (In the above formula, A is a polymer chain containing a structure derived from an α-olefin having 2 to 50 carbon atoms, and i is an integer of 1 or more.)

[0117] In this case, for example, when A is an ethylene homopolymer chain as the vinyl group-containing compound, the silylated polyolefin is estimated to have a structure represented by the following formula (4a): CH3(CH2CH2) j -CH2-CH2-Si(CH3)2O-(-Si(CH3)2-O-) i -Si(CH3)2-CH2-CH2-(CH2CH2) j CH3(4a) (In the above formula, A is a polymer chain containing a structure derived from an α-olefin having 2 to 50 carbon atoms, and i and j are integers of 1 or more.)

[0118] From the viewpoint of suppressing bleeding during molding while ensuring good abrasion resistance, the content of component (F) is 0.1 to 30 parts by mass, preferably 0.5 to 25 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 2 to 15 parts by mass, relative to 100 parts by mass of component (A).

[0119] <Ingredients (G)> The thermoplastic elastomer composition according to the present invention preferably contains a softener (G) (hereinafter referred to as "component (G)"). The softener is not particularly limited, but from the viewpoint of compatibility, process oils composed of hydrocarbons such as paraffinic, naphthenic, and aromatic hydrocarbons are preferred. Among these, process oils mainly composed of paraffinic hydrocarbons are preferred from the viewpoint of weather resistance and colorability, and process oils mainly composed of naphthenic hydrocarbons are preferred from the viewpoint of compatibility with rubber. From the viewpoint of thermal and light stability, the content of aromatic hydrocarbons in the process oil is preferably 10% or less, more preferably 5% or less, and even more preferably 1% or less, in terms of the carbon number ratio specified in ASTM D2140-97.

[0120] From the viewpoint of suppressing oil bleeding while ensuring good flexibility and processability, the content of component (G) is preferably 200 to 500 parts by mass, more preferably 250 to 450 parts by mass, even more preferably 300 to 450 parts by mass, and particularly preferably 300 to 400 parts by mass, per 100 parts by mass of component (A).

[0121] <Other ingredients> The thermoplastic elastomer composition of the present invention may consist of only the components (A) to (F) as long as it is at least partially crosslinked, or may further contain the component (G) in addition to the components (A) to (F). However, the thermoplastic elastomer composition of the present invention may contain, in addition to the components (A) to (F) and optional component (G), other components that do not fall under any of the components (A) to (G) (hereinafter referred to as "other components").

[0122] Here, the crosslinking is usually carried out in the presence of a crosslinking agent. Therefore, in one preferred embodiment of the present invention, the thermoplastic elastomer composition of the present invention further contains a crosslinking agent described below. In this case, it may further contain a crosslinking aid described below. The crosslinking agent and the crosslinking aid will be explained below in the sections "Crosslinking Agent" and "Crosslinking Aid," respectively.

[0123] Crosslinking agent The thermoplastic elastomer composition of the present invention may further contain a crosslinking agent in addition to the components (A) to (F) and optional component (G). Examples of such crosslinking agents include commonly used crosslinking agents such as organic peroxides, phenolic resins, sulfur, hydrosilicone compounds, amino resins, quinones or their derivatives, amine compounds, azo compounds, epoxy compounds, isocyanates, and thermosetting elastomers. In the present invention, the crosslinking agent is preferably an organic peroxide. This organic peroxide acts as a crosslinking initiator for components (A), (B), and (C) during crosslinking and also promotes the decomposition reaction of component (D). As a result, the flowability and moldability of the thermoplastic elastomer composition can be further improved. Even when manufacturing parts with large surface areas and complex shapes, the composition conforms well to molds and fills them more completely without gaps.

[0124] Specific examples of the organic peroxide include 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)cyclododecane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(t-butylperoxy)octane, n-butyl-4,4-bis(t-butylperoxy)butane, n-butyl-4,4-bis Peroxyketals such as (t-butylperoxy)valerate; di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, α,α'-bis(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3, and other dialkyl peroxides; acetyl peroxide, isobutyryl peroxide diacyl peroxides such as octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, and m-trioyl peroxide; t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, and di-t-butyl peroxide peroxyesters such as t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, and cumylperoxyoctate; and hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, and 1,1,3,3-tetramethylbutyl peroxide.

[0125] Among the above compounds, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3 are preferred from the viewpoints of thermal decomposition temperature, crosslinking performance, etc. In one preferred embodiment of the present invention, the crosslinking agent is 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane. From the viewpoint of molding flowability, the amount of such organic peroxide is preferably 1 to 20 parts by mass, more preferably 5 to 15 parts by mass, per 100 parts by mass of the component (A).

[0126] Crosslinking aid In the present invention, a crosslinking aid can be blended in the crosslinking treatment using the organic peroxide. That is, when the thermoplastic elastomer composition of the present invention contains the organic peroxide as the crosslinking agent, the thermoplastic elastomer composition may further contain a crosslinking aid. There are no particular restrictions on the crosslinking aid that can be used in the present invention, as long as it does not impair the effects of the present invention. However, since the crosslinking reaction rate can be controlled, the crosslinking aid is preferably a monofunctional monomer or a polyfunctional monomer.

[0127] As the monofunctional monomer, for example, a radically polymerizable vinyl monomer is preferable, and examples thereof include an aromatic vinyl monomer, an unsaturated nitrile monomer such as acrylonitrile or methacrylonitrile, an acrylic acid ester monomer, a methacrylic acid ester monomer, an acrylic acid monomer, a methacrylic acid monomer, a maleic anhydride monomer, and an N-substituted maleimide monomer.

[0128] Specific examples of monofunctional monomers include styrene, methylstyrene, chloromethylstyrene, hydroxystyrene, tert-butoxystyrene, acetoxystyrene, chlorostyrene, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, maleic anhydride, methylmaleic anhydride, 1,2-dimethylmaleic anhydride, ethylmaleic anhydride, phenylmaleic anhydride, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, and N-cetylmaleimide. Among these, styrene, acrylonitrile, methacrylonitrile, methyl acrylate, maleic anhydride, and N-methylmaleimide are preferred from the viewpoints of reactivity and versatility. These monofunctional monomers may be used alone or in combination of two or more.

[0129] The polyfunctional monomer is a monomer having a plurality of radically polymerizable functional groups as functional groups, and is preferably a monomer having a vinyl group. The number of functional groups in the polyfunctional monomer is preferably two or three.

[0130] Specific examples of polyfunctional monomers include divinylbenzene, triallyl isocyanurate, triallyl cyanurate, diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, p-quinone dioxime, p,p'-dibenzoylquinone dioxime, phenylmaleimide, allyl methacrylate, N,N'-m-phenylene bismaleimide, diallyl phthalate, tetraallyloxyethane, and 1,2-polybutadiene, with divinylbenzene and triallyl isocyanurate being more preferred. These polyfunctional monomers may be used alone or in combination of two or more.

[0131] The amount of the crosslinking aid used can be appropriately set as long as the effects of the present invention can be obtained. For example, when divinylbenzene (DVB) and triallyl isocyanurate (TAIC) are used in combination as the crosslinking aid, it is preferable to use 0.5 to 5 parts by mass of divinylbenzene (DVB) and 0.5 to 10 parts by mass of triallyl isocyanurate (TAIC) relative to 100 parts by mass of the component (A), more preferably 0.5 to 3 parts by mass of divinylbenzene (DVB) and 0.5 to 7 parts by mass of triallyl isocyanurate (TAIC).

[0132] Other additives The thermoplastic elastomer composition of the present invention may contain components other than the components (A) to (F), the optional component (G), the optional crosslinking agent, and the optional crosslinking aid, such as inorganic fillers, plasticizers, and other additives (hereinafter referred to as "other additives"), as needed, within a range that does not impair the object of the present invention.

[0133] Examples of inorganic fillers include calcium carbonate, magnesium carbonate, silica, carbon black, glass fiber, titanium oxide, clay, mica, talc, magnesium hydroxide, and aluminum hydroxide.

[0134] Examples of the plasticizer include polyethylene glycol, phthalate esters such as dioctyl phthalate (DOP), and the like. Other additives include organic and inorganic pigments such as carbon black, titanium dioxide, and phthalocyanine black; heat stabilizers such as 2,6-di-t-butyl-4-methylphenol and n-octadecyl-3-(3,5'-di-t-butyl-4-hydroxyphenyl)propionate; antioxidants such as trisnonylphenyl phosphite and distearyl pentaerythritol diphosphite; ultraviolet absorbers such as 2-(2'-hydroxy-5'methylphenyl)benzotriazole and 2,4-dihydroxybenzophenone; bis-[2,2,6,6-tetramethyl-4-piperidinyl]sebacate, tetrakis(trimethylsilyl)propionate, and the like. Examples of suitable anti-static agents include light stabilizers such as bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,2,3,4-butanetetracarboxylate; flame retardants such as ammonium polyphosphate, trioctyl phosphate, and magnesium hydroxide; silicone oils such as dimethyl silicone oil and methylphenyl silicone oil; antiblocking agents such as stearic acid amide and erucic acid amide; foaming agents such as sodium bicarbonate and N,N'-dinitrosopentamethylenetetramine; antistatic agents such as palmitic acid monoglyceride and stearic acid monoglyceride; and antibacterial agents such as silver ion-supported zeolite and silver thiosulfite complex. The amounts of the other additives added to the thermoplastic elastomer composition can be adjusted as appropriate within a range that does not impair the object of the present invention.

[0135] <Configuration of Thermoplastic Elastomer Composition> As described above, the thermoplastic elastomer composition of the present invention contains the components (A) to (F) and is at least partially crosslinked. Here, this thermoplastic elastomer composition may further contain the above-mentioned "other components."

[0136] The thermoplastic elastomer composition of the present invention preferably satisfies the following requirements (1) and (2): Requirement (1): From the viewpoint of good moldability, the thermoplastic elastomer composition of the present invention preferably has a melt flow rate (MFR, 230°C, 1.2 kg load) measured in accordance with ASTM D1238 of 30 to 90 g / 10 min, more preferably 35 to 80 g / 10 min, and even more preferably 40 to 70 g / 10 min.

[0137] Requirement (2): The thermoplastic elastomer composition of the present invention preferably has a surface hardness (JIS A hardness, instantaneous value) measured in accordance with JIS K7215 of 50 to 100, more preferably 60 to 95, and even more preferably 70 to 90, in order to obtain a good feel when molded into a product. Furthermore, the thermoplastic elastomer composition of the present invention preferably satisfies the following requirement (3) in addition to the requirements (1) and (2):

[0138] Requirement (3): The thermoplastic elastomer composition of the present invention preferably has a surface hardness (JIS A hardness, value after 10 seconds) measured in accordance with JIS K7215 of 50 to 100, more preferably 60 to 95, and even more preferably 70 to 90, in order to obtain a molded article with a good feel.

[0139] The thermoplastic elastomer composition satisfying the requirements (1) and (2), preferably the requirements (1) to (3), can be produced by any method as long as the requirements are satisfied, but for example, the method can be produced by taking into consideration the following description.

[0140] Regarding the requirement (1), the MFR of the thermoplastic elastomer composition can be adjusted by changing the amount of organic peroxide added when mixing the raw material components in an extruder. For example, the MFR of the resulting thermoplastic elastomer composition tends to increase as the amount of organic peroxide added increases.

[0141] Regarding the requirements (2) and (3), the surface hardness of the thermoplastic elastomer composition can be adjusted by changing the composition of the thermoplastic elastomer composition. For example, the smaller the amount of softener added, the greater the surface hardness of the resulting thermoplastic elastomer composition tends to be. In this way, by appropriately adjusting the amount of organic peroxide added and the composition of the thermoplastic elastomer composition, a thermoplastic elastomer composition that satisfies the above requirements (1) to (3) can be obtained.

[0142] <Method of producing thermoplastic elastomer composition> The thermoplastic elastomer composition of the present invention can be obtained by crosslinking a mixture containing the components (A) to (F). The method for crosslinking is not particularly limited, and any known method may be used. The crosslinking is preferably carried out in the presence of the crosslinking agent. The conditions for the crosslinking reaction are not particularly limited, and suitable conditions can be selected as appropriate depending on the desired physical properties of the thermoplastic elastomer composition of the present embodiment.

[0143] The thermoplastic elastomer composition of this embodiment can be produced using a common method, such as a Banbury mixer, kneader, single-screw extruder, or twin-screw extruder, which are used in the production of typical elastomer compositions. Among these, a twin-screw extruder is preferred from the viewpoint of efficiently achieving dynamic crosslinking of the thermoplastic elastomer. When using a twin-screw extruder, all of the constituent components may be mixed together, or some of the components may be mixed and then the other components may be added. For example, when producing a thermoplastic elastomer composition containing component (G), it is more suitable to mix all of the components other than component (G) together and then add component (G), which can initiate a crosslinking reaction in the composition and allow continuous production of the thermoplastic elastomer composition.

[0144] The mixture containing the components (A) to (F) is often melt-kneaded to form the thermoplastic elastomer composition of the present invention. When a twin-screw extruder is used, the temperature at which the melt-kneading is carried out can be, for example, 160 to 230°C.

[0145] Furthermore, when the crosslinking agent is added to the mixture containing the components (A) to (F), the crosslinking agent may be added to the extruder together with the components (A) to (F) from the beginning, or a portion of the crosslinking agent may be added midway through the extruder. The same can be said for the crosslinking aid. Here, when the crosslinking agent and the crosslinking aid are used in combination, the addition of the crosslinking agent and the crosslinking aid may be carried out in such a manner that the crosslinking agent and the crosslinking aid are mixed in advance to form a crosslinking agent mixture, and this crosslinking agent mixture is then mixed with the components (A) to (F).

[0146] When the thermoplastic elastomer composition of the present invention contains a crosslinking agent, when it is heated, melted, and kneaded in an extruder, components (A), (B), and (C) undergo a crosslinking reaction with the crosslinking agent, and at the same time, the decomposition reaction of component (D) is promoted by the crosslinking agent, thereby improving molding flowability. Furthermore, by adding component (G) and other components and melt-kneading, and then thoroughly carrying out the crosslinking reaction and kneading and dispersion, pellets of the thermoplastic elastomer composition can be obtained by removing the composition from the extruder.

[0147] [Molded body] The molded article according to the present invention includes the thermoplastic elastomer composition. The molded article may be in the form of a film or a sheet. Examples of uses of the molded article include automotive interior materials.

[0148] Such a molded article according to the present invention can be obtained by molding the thermoplastic elastomer composition using various molding methods. Examples of such molding methods include injection molding, extrusion molding, vacuum molding, pressure molding, blow molding, calendar molding, and foam molding. For example, a molded article such as a skin material can be obtained by filling a mold with the thermoplastic elastomer composition melted by heating, solidifying it, and then demolding it.

[0149] The thermoplastic elastomer composition of the present embodiment is preferably formed into an injection-molded article. When formed into an injection-molded article, productivity is excellent. The shape of the injection-molded article is not particularly limited, but from the viewpoint of use as a skin material, it is preferably a film or sheet.

[0150] The injection-molded article can be used for various components, but is particularly preferred as an automotive interior material, from the viewpoint that it is possible to injection-molde thin-walled molded articles with complex shapes with good reproducibility. Among automotive interior materials, instrument panels typically have complex shapes that are not only thin and have a large surface area, but also have grain patterns on the surface, partial openings, flat and curved portions, three-dimensional structures, and thick and thin portions. According to this embodiment, an injection-molded article with a thin wall and a large surface area can be obtained, making it suitable for use as an instrument panel or a component thereof.

[0151] The shape and configuration of the automotive interior material are not particularly limited, and can be appropriately selected depending on the application, etc. One preferred example is a laminate comprising a layer containing the automotive interior material of this embodiment (hereinafter sometimes referred to as a "skin material layer") and a layer containing a core material (hereinafter sometimes referred to as a "core material layer") laminated on the layer containing the automotive interior material. By using a laminate that combines not only a skin material layer but also a core material layer, even complex three-dimensional shapes can be mass-produced stably, thereby improving production efficiency and reducing costs.

[0152] The core material is not particularly limited and may be any known material, such as polypropylene, acrylonitrile-butadiene-styrene (ABS) resin, polycarbonate / acrylonitrile-butadiene-styrene alloy (PC / ABS alloy), acrylonitrile-styrene copolymer, modified polyphenylene oxide, or resins containing fillers such as talc or glass fiber mixed into them as needed to improve strength. Among these, preferred are those containing at least one selected from the group consisting of polypropylene, acrylonitrile-butadiene-styrene (ABS) resin, polycarbonate / acrylonitrile-butadiene-styrene alloy (PC / ABS alloy), and polyphenylene ether. Furthermore, polypropylene is more preferred from the standpoint of lightweight properties.

[0153] The layer structure of the laminate of this embodiment is not particularly limited, and may be a two-layer or more structure including at least a skin layer and a core layer. In this embodiment, the skin layer and the core layer do not necessarily need to be in contact with each other, and another layer may be present between the skin layer and the core layer.

[0154] The thickness of the skin layer is not particularly limited, but is preferably 0.5 to 2.0 mm, and more preferably 0.8 to 1.5 mm. A skin layer thickness of 0.5 mm or more can provide better appearance, chemical resistance, and abrasion resistance, while a skin layer thickness of 2.0 mm or less can provide better cost performance and tactile feel. While it has been difficult to efficiently produce such a thin skin layer using conventional techniques, the use of the thermoplastic elastomer composition of the present embodiment makes it possible to easily produce such a thin skin layer.

[0155] The thickness of the core layer is not particularly limited, but is preferably 2.0 to 4.5 mm, and more preferably 2.5 to 3.5 mm. By making the core layer thickness 2.0 mm or more, it is possible to achieve even better rigidity, heat resistance, and moldability, and by making it 4.5 mm or less, it is possible to achieve even better economy and lightness.

[0156] Furthermore, the laminate of the present embodiment preferably further comprises a layer containing a foam material between the skin layer and the core layer, and the foam material has a density of 100 to 250 kg / m 3 It is more preferable that the foam contains a thermosetting urethane foam having a density of 100 kg / m 3 By setting the density of the foam material at 250 kg / m or more, it is possible to make it difficult for indentations to be made during handling during production or removal, and to improve handling properties. 3 By setting the density of the foam material to 120 to 180 kg / m or less, it is possible to impart appropriate flexibility to the laminate. 3 It is more preferable that:

[0157] The type of thermosetting urethane foam is not particularly limited, but semi-rigid thermosetting urethane foam is preferred. Semi-rigid thermosetting urethane foam refers to urethane foam with an open cell structure of 90% or more.

[0158] The method for producing the laminate is not particularly limited, and known methods can be used, such as a method in which the skin material, core material, and foam material are molded separately, and then these members are laminated using a chloroprene-based adhesive or the like to form a layer structure, or a method in which the core material is molded in advance, and then the core material is placed in a mold and molded integrally with the molding of the skin material (integral molding), and the core material and the two members are laminated to form a layer structure.

[0159] The above-mentioned layer structure makes it possible to obtain a laminate having a uniform thickness, good grain reproducibility, and a skin material with a good feel and appearance, while also enabling stable mass production of even complex three-dimensional shapes. Furthermore, by using a layer structure of three or more layers including the above-mentioned foam material, it is possible to obtain a laminate that further utilizes the soft feel of the skin material.

[0160] The laminate can be suitably used as an automotive interior material, such as an instrument panel, a door panel, or a glove box lid, which are thin and have a large surface area and have been difficult to produce by injection molding in the past, and is particularly suitable as an instrument panel.

[0161] The instrument panel of this embodiment provides the same effects as those described in the embodiments of the automotive skin material and laminate. Furthermore, the skin material has good elongation properties at low temperatures, making it easier to ensure the low-temperature deployment performance of the passenger airbag. It also makes it possible to maintain and improve design freedom, for example, by making the skin material seamless in the airbag installation area. [Example]

[0162] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, various physical properties were measured as follows.

[0163] [Measurement method for each component] The test methods for each component of the raw materials used in the examples and comparative examples are as follows.

[0164] <Hydrogenation rate (%)> The hydrogenation rate was measured by nuclear magnetic resonance spectroscopy (NMR). A nuclear magnetic resonance spectrometer (JEOL, model name "JNM-LA400") was used as the measuring instrument, deuterated chloroform was used as the solvent, and tetramethylsilane (TMS) was used as the chemical shift standard. The conditions were a sample concentration of 50 mg / mL, an observation frequency of 400 MHz, a pulse delay of 2.904 seconds, a scan count of 64, a pulse width of 45°C, and a measurement temperature of 26°C. 1 H-NMR measurements were carried out.

[0165] <Content of monomer units and bond units> The contents of vinyl aromatic monomer units, ethylene monomer units, butylene monomer units, and 1,4-bond units, 1,2-bond units, and 3,4-bond units of butadiene were measured by NMR. A nuclear magnetic resonance analyzer (manufactured by JEOL, model name "JNM-LA400") was used as the measuring instrument, deuterated chloroform was used as the solvent, and tetramethylsilane (TMS) was used as the chemical shift standard. The conditions were a sample concentration of 50 mg / mL, an observation frequency of 400 MHz, a pulse delay of 2.904 seconds, a scan count of 64, a pulse width of 45°C, and a measurement temperature of 26°C. 1 H-NMR measurements were carried out.

[0166] <Styrene polymer block content (Os value)> The styrene polymer block content was measured using the copolymer before hydrogenation by the method described in I.M. Kolthoff, et al., J. Polym. Sci. 1, 429 (1946) (osmium tetroxide decomposition method). A 0.1 g / 125 mL tertiary butanol solution of osmic acid was used to decompose the copolymer before hydrogenation. The styrene polymer block content was calculated using the following formula. The styrene polymer block content obtained here is referred to as the "Os value." Styrene polymer block content (Os value; mass%) = (mass of styrene polymer block in copolymer before hydrogenation) / (mass of copolymer before hydrogenation) × 100

[0167] <Method for measuring molecular weight> The number-average molecular weight (Mn), weight-average molecular weight (Mw), and molecular weight distribution (Mw / Mn) were measured using a Millipore GPC-150 as follows. Specifically, a TSK GNH HT separation column with a diameter of 7.5 mm and a length of 300 mm was used. The column temperature was 140°C, and the mobile phase consisted of ortho-dichlorobenzene (Wako Pure Chemical Industries, Ltd.) and 0.025% by mass of BHT (Takeda Pharmaceutical Co., Ltd.) as an antioxidant. The flow rate of the mobile phase was 1.0 ml / min. The sample concentration was 0.1% by mass, and the sample injection volume was 500 microliters. A differential refractometer was used as the detector. A calibration curve was prepared using standard polystyrene, and values ​​were converted to polyethylene equivalent values ​​according to the usual method. In the following synthesis examples, the number of moles of the raw material polymers is all represented by values based on Mn.

[0168] <Measurement method of melting point> The melting point (Tm) was the peak top temperature obtained by measurement using DSC. The apparatus used was DSC-60A manufactured by Shimadzu Corporation. The reference cell used alumina, and the nitrogen flow rate was set at 50 ml / min. Also, the measurement was carried out under the temperature rising condition from 30°C to 300°C at 10°C / min. Before this temperature rising measurement, it is preferable to once raise the temperature of the resin to about 200°C, hold it for 5 minutes, and then lower the temperature to room temperature (25°C) at 20°C / min to uniformize the thermal history of the resin.

[0169] <Measurement and calculation methods of yield, conversion rate, isomerization rate, and terminal unsaturation rate by NMR analysis> The yield, conversion rate, isomerization rate, and terminal unsaturation rate of the silylated polyolefin are 1 determined by 1H-NMR. The yield is the ratio of the number of moles of the obtained silylated polyolefin to the number of moles of the vinyl group-containing compound in the raw material, the conversion rate is the ratio of the consumed number of moles to the number of moles of the vinyl group-containing compound in the raw material, the isomerization rate is the ratio of the number of moles of the vinylene form generated to the number of moles of the vinyl group-containing compound in the raw material, and the terminal unsaturation rate is defined as the ratio of the main chain terminal vinyl group to the total of the main chain terminal vinyl group and the terminal methyl group of the vinyl group-containing compound as the raw material. In addition, the terminal unsaturation rate and the number of vinyl groups per thousand carbons are generally applied to the vinyl group-containing compound as the raw material, but in cases where hydrosilylation is not sufficient, etc., they may also be applied to the silylated polyolefin as an index of the remaining amount of unreacted raw material.

[0170] For example, in the silylated polyolefin obtained by hydrosilylation of a main-chain terminal vinyl group-containing compound consisting only of ethylene with triethoxysilane, a six-proton peak (C) corresponding to the ethoxy methylene group is observed at 3.8 ppm, and a two-proton peak (D) corresponding to the isomerized vinylene group is observed at 5.4 ppm. If the hydrosilylation is insufficient, a two-proton peak (E) corresponding to the unreacted vinyl group is observed at 4.8-5.1 ppm, and a one-proton peak (F) is observed at 5.6-5.8 ppm. For the vinyl group-containing raw material compound, a two-proton main-chain methylene (G) is observed at 1.0-1.5 ppm, and for those without vinyl groups at the main-chain terminal, a three-proton terminal methyl (H) is observed at 0.8 ppm. Furthermore, a two-proton peak (I) corresponding to the carbon adjacent to the double bond is observed at 1.9 ppm.

[0171] If the peak areas of the peaks (C), (D), (E), (F), (G), (H), and (I) are SC, SD, SE, SF, SG, SH, and SI, respectively, the yield (YLD (%)), conversion rate (CVS (%)), isomerization rate (ISO (%)), and terminal unsaturation rate (VE (%)) can be calculated using the following formulas.

[0172] YLD(%)=(SC / 3) / (SC / 3+SD+SE)×100 CVS(%)={1-SE / (SC / 3+SD+SE)}×100 ISO (%) = SD / (SC / 3 + SD + SE) x 100 VE(%)=SE / (SE / 2+SH / 3)×100

[0173] <Melt flow rate (MFR) measurement method> The melt flow rate (MFR) of polyethylene as the vinyl group-containing compound was measured at 190° C. and a load of 2.16 kg using a Melt Indexer T-111 manufactured by Tokyo Seiki Co., Ltd.

[0174] [Raw materials] In the examples and comparative examples, the following components were used to form the compositions.

[0175] <Hydrogenation catalyst> The hydrogenation catalyst used in the hydrogenation reaction of the following block copolymer was prepared by the following method. A nitrogen-substituted reaction vessel was charged with 1 L of dried and purified cyclohexane, and 100 mmol of bis(cyclopentadienyl)titanium dichloride was added. With thorough stirring, an n-hexane solution containing 200 mmol of trimethylaluminum was added, and the mixture was allowed to react at room temperature for approximately 3 days.

[0176] <(A) Hydrogenated Block Copolymer Having at Least One Conjugated Diene Monomer Unit Block and at Least One Vinyl Aromatic Monomer Unit Block> As component (A), the following hydrogenated products (A-1) and (A-2) were used.

[0177] (A-1) Production of hydrogenated block copolymer (1) Preparation of block copolymers Batch polymerization was carried out using a 10 L tank reactor equipped with a stirrer and a jacket. First, 6.4 L of dried and purified cyclohexane and 175 g of styrene were added. Tetramethylethylenediamine (TMEDA) was added in advance so that the molar ratio was 0.30 times the number of moles of Li in the n-butyllithium initiator, resulting in 11 mmol of Li in the n-butyllithium initiator. Polymerization was then carried out at an initial temperature of 65°C. After completion of the polymerization, a cyclohexane solution containing 650 g of butadiene (monomer concentration 22% by mass) was continuously fed into the reactor at a constant rate over 60 minutes, and then a cyclohexane solution containing 175 g of styrene (monomer concentration 22% by mass) was further added over 10 minutes to obtain a copolymer. The resulting copolymer had a styrene polymer block content of 35% by mass and a vinyl bond content of 36%.

[0178] (2) Hydrogenation of block copolymers The hydrogenation catalyst was added to the copolymer obtained in (1) above so that the amount was 100 ppm in terms of titanium per 100 parts by mass of the copolymer, and the hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 75°C to obtain a reaction solution. Octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to the obtained reaction solution in an amount of 0.3 parts by mass per 100 parts by mass of the hydrogenated block copolymer. The weight-average molecular weight of the obtained hydrogenated block copolymer (A-1) was 150,000, and the hydrogenation rate of the butadiene double bonds contained in the hydrogenated block copolymer (A-1) was 99%.

[0179] (A-2) Production of hydrogenated block copolymer (1) Preparation of block copolymers Batch polymerization was carried out using a 10 L tank reactor equipped with a stirrer and a jacket. First, 6.4 L of cyclohexane and 325 g of styrene were added. TMEDA was added in a molar amount equal to 0.40 times the number of moles of Li in n-butyllithium, followed by 20 mmol of n-butyllithium initiator Li. Polymerization was carried out at an initial temperature of 65°C. After completion of the polymerization, a cyclohexane solution containing 350 g of butadiene (monomer concentration: 22% by mass) was continuously fed into the reactor at a constant rate over 60 minutes. A cyclohexane solution containing 325 g of styrene (monomer concentration: 22% by mass) was then added over 10 minutes to obtain a copolymer. The resulting copolymer had a styrene polymer block content of 65% by mass and a vinyl bond content of 40%.

[0180] (2) Hydrogenation of block copolymers The above hydrogenation catalyst was added to the copolymer obtained in (1) above in an amount of 100 ppm titanium per 100 parts by mass of polymer. Then, a hydrogenation reaction was carried out under a hydrogen pressure of 0.7 MPa at a temperature of 75°C. To the resulting polymer solution, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer per 100 parts by mass of the hydrogenated block copolymer. The weight-average molecular weight of the resulting hydrogenated block copolymer (A-2) was 50,000, and the hydrogenation rate of the butadiene double bonds contained in the hydrogenated block copolymer (A-2) was 99%.

[0181] <(B) Copolymer Having at Least One Hydrogenated Copolymer Block Mainly Containing Conjugated Diene Monomer Units and Vinyl Aromatic Monomer Units> As the component (B), the following copolymer (B-1) was used.

[0182] (B-1) Production of hydrogenated block copolymer (1) Preparation of block copolymers Batch polymerization was carried out using a 10 L tank reactor equipped with a stirrer and a jacket. Initially, 6.4 L of cyclohexane and 75 g of styrene were added. TMEDA was added in advance so that the molar ratio was 0.25 times the number of moles of Li in n-butyllithium. The n-butyllithium initiator was then added so that the number of moles of Li was 10 mmol. Polymerization was carried out at an initial temperature of 65 °C. After polymerization was completed, a cyclohexane solution containing 470 g of butadiene and 380 g of styrene (monomer concentration: 22% by mass) was continuously fed into the reactor at a constant rate over 60 minutes. After polymerization settling, a cyclohexane solution containing 75 g of styrene (monomer concentration: 22% by mass) was added over 10 minutes to obtain a copolymer. The styrene content of the resulting copolymer was 53% by mass, the styrene polymer block content of the copolymer was 15% by mass, the styrene content of the copolymer block (i.e., the copolymer block containing conjugated diene monomer units and vinyl aromatic monomer units) was 45% by mass, and the vinyl bond content was 23%.

[0183] (2) Hydrogenation of block copolymers The copolymer obtained in (1) above was added with the hydrogenation catalyst in an amount of 100 ppm (calculated as titanium) per 100 parts by mass of polymer, and the hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 75°C. To the resulting polymer solution, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer per 100 parts by mass of the hydrogenated block copolymer. The weight-average molecular weight of the resulting hydrogenated block copolymer (B-1) was 160,000, and the hydrogenation rate of the butadiene double bonds contained in the hydrogenated block copolymer (B-1) was 99%. Furthermore, one of the tan δ peaks obtained by viscoelasticity measurement was present at -15°C.

[0184] <(C) Ethylene-α-olefin copolymer> As the ethylene-α-olefin copolymer (C) (referred to as component (C)), a copolymer of ethylene and 1-octene (manufactured by The Dow Chemical Company under the trade name "Engage 8842") (hereinafter referred to as "C-1") was used. The ethylene content of this copolymer was 55% by mass, and the 1-octene content was 45% by mass.

[0185] <(D) Propylene-based polymer> As the propylene polymer (D) (referred to as component (D)), a homopolymer type polypropylene (melt flow rate (MFR) at 230°C and a load of 2.16 kg: 0.5 g / 10 min; weight average molecular weight: 6.6 × 10) manufactured by SunAllomer Co., Ltd. was used. 5 ) (hereinafter referred to as "D-1") was used.

[0186] <(E) Polyorganosiloxane> As the polyorganosiloxane (E) (referred to as component (E)), Shin-Etsu Chemical Co., Ltd., product name "KF-96H-6 Man CS" (hereinafter referred to as "E-1"), and Product name: "MB50-001; a blend of high molecular weight polyorganosiloxane and homopolypropylene (silicone content: 50% by mass)" manufactured by Dow Corning Toray Co., Ltd. (hereinafter referred to as "E-2") was used.

[0187] <(F) Silylated Polyolefin> The following olefin-modified silicone copolymer (F-1) was used as the silylated polyolefin (F) (referred to as component (F)).

[0188] (F-1) Production of Olefin-Modified Silicone Copolymer [Synthesis Example 1] (1) Synthesis of polyethylene with a vinyl group at one end A 100 ml reactor that had been thoroughly dried and purged with nitrogen was charged with 3.89 g (15.0 mmol) of 3-cumyl-5-methylsalicylaldehyde, 30 ml of toluene, and 2.54 g (40% aqueous solution, 22.5 mmol) of ethylamine, and the mixture was stirred at room temperature for 5 hours. The reaction solution was concentrated under reduced pressure and purified by silica gel column chromatography to obtain compound (a) as a yellow oil.

[0189] A thoroughly dried, argon-purged 100 ml reactor was charged with 1.12 g (4.00 mmol) of the compound (a) obtained above and 25 ml of diethyl ether, cooled to -78 °C, and stirred. To this was added 2.58 ml of n-butyllithium (n-hexane solution, 1.55 M, 4.00 mmol) dropwise over 5 minutes. The mixture was stirred at this temperature for 2 hours, then slowly warmed to room temperature and stirred at room temperature for an additional 3 hours to prepare the lithium salt. This solution was added dropwise to 25 ml of tetrahydrofuran solution containing 0.76 g (2.00 mol) of ZrCl4(THF)2 complex, which had been cooled to -78 °C. After the addition, the mixture was slowly warmed to room temperature while stirring continued. After stirring at room temperature for an additional 12 hours, the reaction mixture was evaporated. The resulting solid was dissolved in 50 ml of methylene chloride, and insoluble matter was removed using a glass filter. The filtrate was concentrated under reduced pressure, and the precipitated solid was reprecipitated with n-hexane and dried under reduced pressure to obtain compound (b) as a yellow powder.

[0190] A 2000 ml stainless steel autoclave, the atmosphere of which had been thoroughly purged with nitrogen, was charged with 1000 ml of heptane at room temperature and heated to 150°C. The autoclave was then heated with ethylene at 30 kg / cm. 2 The pressure was increased to 1000 kJ / min, and the temperature was maintained. 0.5 ml (0.5 mmol) of a hexane solution (1.00 mmol / ml in terms of aluminum atom) of MMAO (manufactured by Tosoh Finechem Co., Ltd.) was injected, followed by 0.5 ml (0.0001 mmol) of a toluene solution of the above compound (b) (0.0002 mmol / ml) to initiate polymerization. Polymerization was carried out at 150°C for 30 minutes under an ethylene gas atmosphere, and then the polymerization was terminated by injecting a small amount of methanol. The obtained polymer solution was added to 3 liters of methanol containing a small amount of hydrochloric acid to precipitate the polymer. After washing with methanol, the polymer was dried under reduced pressure at 80°C for 10 hours.

[0191] 1 H-NMR analysis revealed that the resulting polymer was homopolyethylene and contained a double bond at only one terminal. The physical properties of this ethylene-based polymer (c) (single unit) containing a double bond at only one terminal were as follows: Melting point (Tm) 123℃ Mw=4770, Mw / Mn=2.25 (GPC) Terminal unsaturation rate 97%

[0192] [Synthesis Example 2] (2) Preparation of platinum catalyst composition (d) In a 50 ml sample tube equipped with a magnetic stirrer tip, 0.50 g of platinum(II) chloride was suspended in 10 ml of hydrosilane A (HS(A), manufactured by Momentive Performance Materials Japan, LLC, product number XF40-C2195) having the following structure, and the suspension was stirred at room temperature under a nitrogen stream. After stirring for 190 hours, approximately 0.4 ml of the reaction solution was sampled using a syringe and filtered through a 0.45 μm PTFE filter. The filtrate was collected in a 10 ml sample tube, yielding platinum catalyst composition (d-1) with a platinum concentration of 3.8% by mass. Hydrosilane A (HS(A)): HSi(CH3)2O-(-Si(CH3)2-O-) 18 -Si(CH3)2H

[0193] [Synthesis Example 3] (3) Introduction of polyethylene with terminal vinyl groups into hydrosilane A 300 ml two-neck flask was charged with 25.1 g (11.8 mmol) of the ethylene polymer (c) having a vinyl group at one end obtained in [Synthesis Example 1], and under a nitrogen atmosphere, 8.7 g (5.9 mmol; equivalent to 11.8 mmol as Si-H groups) of the hydrosilane A (HS(A)) and 150 μl (1.4 × 10 in terms of Pt) of (C') obtained by diluting the platinum catalyst composition (d) prepared in [Synthesis Example 2] 200 times with hydrosilane A (HS(A)). -6 (mmol) was charged. The reactor was placed in an oil bath whose internal temperature had been raised to 130°C and stirred. After approximately 3 minutes, the polymer melted. After 6 hours, the mixture was cooled, approximately 200 ml of methanol was added, and the contents were transferred to a 300 ml beaker and stirred for 2 hours. The solid was then filtered, washed with methanol, and dried at 60°C under reduced pressure of 2 hPa or less, yielding 33.1 g of a white solid olefin-modified silicone copolymer (F-1). NMR analysis showed that the resulting olefin-modified silicone copolymer (F-1) had a yield of 98%, an olefin conversion rate of 100%, and an isomerization rate of 2%. The MFR was above the upper measurement limit (MFR > 100 g / 10 min). Here, the content of the silicon-containing compound chain portion in the olefin-modified silicone copolymer (F-1), calculated from the molecular formula assuming that the olefin-modified silicone copolymer (F-1) is composed of a polyolefin chain and a silicon-containing compound chain, was 26 mass%.

[0194] <(G) Softener> As the softener (G) (referred to as component (G)), a paraffinic oil (manufactured by Idemitsu Kosan Co., Ltd., trade name "Diana Process Oil PW-100") (hereinafter referred to as "G-1") was used.

[0195] <Crosslinking agents and crosslinking aids> The crosslinking agent was mixed with the crosslinking coagent described below and used in the form of a crosslinking agent mixture. Here, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane (manufactured by NOF Corporation, trade name "Perhexa 25B") was used as the crosslinking agent.

[0196] The cross-linking aid (polyfunctional monomer) blended with the cross-linking agent is as follows: Here, the amount of the cross-linking aid is the amount relative to 100 parts by mass of the cross-linking agent. Crosslinking aid 1 (triallyl isocyanurate (manufactured by Nippon Kasei Co., Ltd.; hereinafter referred to as "TAIC")) 12.5 parts by mass Crosslinking aid 2 (divinylbenzene (manufactured by Wako Pure Chemical Industries, Ltd.; hereinafter referred to as "DVB")) 50 parts by mass

[0197] [Examples 1 to 4 and Comparative Examples 1 to 5] The extruder used was a twin-screw extruder ("KTX-46" manufactured by Kobe Steel, Ltd.) with an oil inlet in the center of the barrel. The screw used was a two-start screw with kneading sections before and after the inlet.

[0198] The raw materials listed in Tables 1-1 and 1-2 below, except for the softener, were mixed together in the composition ratios (parts by mass) listed in Tables 1-1 and 1-2 below, and then introduced into a twin-screw extruder (cylinder temperature 200°C) using a constant feeder. Subsequently, a predetermined amount of softener was injected using a pump through an injection port in the center of the twin-screw extruder, and melt extrusion was carried out to obtain a thermoplastic elastomer composition. This thermoplastic elastomer composition was used as an evaluation sample for the physical property evaluation described in (1) below.

[0199] The thermoplastic elastomer composition obtained above was compression molded at 200°C using a heated press ("T-50" manufactured by Toho Press Manufacturing Co., Ltd.) to produce a sheet with a thickness of 2 mm, which was used as an evaluation sample for the physical property evaluations (2) and (3) below.

[0200] The thermoplastic elastomer composition obtained above was injection molded into a 1 mm thick sheet using a flat mold measuring 15 cm long x 9 cm wide and having a leather grain finish. The resulting 1 mm thick sheet was used as an evaluation sample for the physical property evaluation in (4) below. The injection molding machine used was the "M150CL-DM" manufactured by Meiki Seisakusho Co., Ltd. The molding conditions were a resin temperature of 220°C and a mold temperature of 40°C.

[0201] [Measurement method for thermoplastic elastomer composition] (1) Melt flow rate (MFR) The melt flow rate (MFR) was measured in accordance with ASTM D 1238. The measurement conditions were a heating temperature of 230°C and a load of 1.2 kg.

[0202] (2) Surface hardness (JIS A hardness) The surface hardness was measured by stacking four 2 mm thick sample sheets in accordance with JIS K7215 using Type A in an atmosphere of 23°C. A durometer was pressed against the sheets, and the value immediately after applying the test load (instantaneous value) and the value 10 seconds after applying the test load (10 second value) were measured.

[0203] (3) Abrasion resistance Using a Gakushin Type I abrasion tester (flat surface), a 20mm wide SUS abrader (tip R60) and four layers of white cotton cloth (Kanakin No. 3) were used as the abrasion cloth, and an abrasion test was carried out five times with a load of 24.5 N and a stroke of 140 mm, and the damaged area was observed and evaluated. Evaluation was based on the following criteria. Excellent: Almost no change in appearance due to wear is observed Good: Slight changes in appearance due to wear are observed Fair: Changes in appearance due to wear are observed Unacceptable: Significant change in appearance due to wear

[0204] (4) Texture evaluation The 1 mm thick sheet obtained by the above injection molding was subjected to a tactile evaluation. The tactile evaluation was conducted blindly (a method of evaluation based solely on the feel of the material, without taking into account visual perceptions such as "it looks moist" or "it looks soft"), and participants rated the feel of the material when touched with the palm of their hand on a 5-point scale. A conventional skin material made from olefin-based thermoplastic elastomer (TPO-based: Mitsui Chemicals' Milastomer 5030NHS) (a skin made by vacuum drawing) was used as the reference point (3 points), and the evaluation was based on the following criteria. 5 points: Feels much better than conventional olefin-based thermoplastic elastomer (TPO) skin materials. 4 points: Feels slightly better to the touch than conventional olefin-based thermoplastic elastomer (TPO) skin materials. 3 points: Feels similar to conventional olefin-based thermoplastic elastomer (TPO) skin materials. 2 points: Compared to conventional olefin-based thermoplastic elastomer (TPO-based) skin materials, the feel is slightly worse. 1 point: Compared to conventional olefin-based thermoplastic elastomer (TPO-based) skin materials, the feel is very poor.

[0205] Here, "good to the touch" refers to something that feels smooth, and "not good to the touch" refers to something that feels sticky. The raw material composition and the evaluation results of the physical properties are shown in Tables 1-1 and 1-2 below. In Tables 1-1 and 1-2 below, among the components constituting E-2, the amount of high molecular weight polyorganosiloxane is listed in the "Amount of siloxane in E-2" column, and the amount of homopolypropylene is listed in the "Amount of PP in E-2 below" column. Furthermore, for "(D) Propylene-based polymer," the total amount of the components constituting D-1 and the "Amount of PP in E-2 below" is listed in the "Subtotal" column.

[0206] Note that the parts by mass listed in Tables 1-1 and 1-2 below are values ​​rounded to the first decimal place, and as a result, the sum of the "siloxane amount in E-2" and the "PP amount in E-2 below" may not match the amount of "E-2."

[0207] [Table 1-1]

[0208] [Table 1-2]

[0209] As is clear from the examples, the thermoplastic elastomer compositions of the present invention have a high MFR and an appropriate surface hardness range, which are fundamental requirements for the performance of interior covering materials. Furthermore, the thermoplastic elastomer compositions of the present invention were superior in abrasion resistance and tactile feel compared to the thermoplastic elastomer compositions obtained in the comparative examples. Thus, the thermoplastic elastomer compositions of the present invention exhibited an excellent balance of MFR, surface hardness, abrasion resistance, and tactile feel.

Claims

1. A thermoplastic elastomer composition comprising the following components (A) to (F), which is at least partially crosslinked: Component (A): 100 parts by mass of a SB type 2 (di-block) linear block copolymer, an SBS type 3 (tri-block) linear block copolymer, or an SBSB type 4 (tetra-block) linear block copolymer (here, a polymer block consisting of a vinyl aromatic monomer unit is represented by "S", and a polymer block consisting of a conjugated diene monomer unit and / or a partially hydrogenated unit thereof is represented by "B"); Component (B): 50 to 250 parts by mass of a copolymer having at least one hydrogenated copolymer block mainly composed of conjugated diene monomer units and vinyl aromatic monomer units; Component (C): 80 to 200 parts by mass of an ethylene / α-olefin copolymer containing ethylene units and α-olefin units, wherein the α-olefin is 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, or 1-dodecene; Component (D): 150 to 300 parts by mass of a propylene polymer; Component (E): 1 to 80 parts by mass of polyorganosiloxane; Component (F): 0.1 to 30 parts by mass of silylated polyolefin.

2. The thermoplastic elastomer composition according to claim 1, which satisfies the following requirements (1) and (2): (1) The melt flow rate (MFR, 230°C, 1.2 kg load) measured in accordance with ASTM D1238 is 30 to 90 g / 10 min. (2) The surface hardness (JIS A hardness, instantaneous value) measured in accordance with JIS K7215 is 50 to 100.

3. 3. The thermoplastic elastomer composition of claim 1, wherein component (F) is a silylated polyethylene.

4. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the component (C) is an ethylene / 1-octene copolymer.

5. moreover, Component (G): Softener 200 to 500 parts by mass The thermoplastic elastomer composition according to any one of claims 1 to 4, comprising:

6. The thermoplastic elastomer composition according to any one of claims 1 to 5, wherein the crosslinking is mediated by an organic peroxide.

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

8. A film or sheet comprising the injection-molded article according to claim 7.

9. An automobile interior material comprising the injection molded article according to claim 7.

Images