Thermoplastic elastomer composition and method for producing thermoplastic elastomer composition

Abstract

The purpose of the present disclosure is to provide a thermoplastic elastomer composition having excellent scratch resistance and capable of forming a low-gloss appearance and a method for manufacturing the same, and the present disclosure relates to a thermoplastic elastomer composition comprising a first composition and a second composition, and a method for manufacturing the same, the first composition contains an olefin resin (A), an ethylene-alpha-olefin copolymer (B), and a cross-linking agent (F), and the second composition contains a hydrogenated product (C) of a block copolymer having at least one block mainly composed of a conjugated diene monomer unit and at least one block mainly composed of a vinyl aromatic monomer unit, the content of the component (B) is 10-180 parts by mass per 100 parts by mass of the component (A), the content of the component (C) is 170-500 parts by mass per 100 parts by mass of the component (A), and the ratio W1 / W0 of the sum W0 of the content of the component (B) and the content of the component (C) to the gel content W1 is 0.01-0.70.

Description

Technical Field

[0001] The present disclosure relates to thermoplastic elastomer compositions and methods of making thermoplastic elastomer compositions. Background Art

[0002] A thermoplastic elastomer composition obtained by crosslinking a radically crosslinkable elastomer and a non-radical crosslinkable resin such as polypropylene while melt-kneading in an extruder in the presence of a radical initiator, so-called dynamic crosslinking, is well known and widely used in applications such as automobile parts.

[0003] As such a thermoplastic elastomer composition, Patent Document 1 discloses a thermoplastic elastomer composition containing an ethylene-α-olefin copolymer and an olefin-based resin as a thermoplastic elastomer composition containing a hydrogenated product of a block copolymer having a vinyl aromatic monomer unit.

[0004] Patent Document 2 discloses a rubber composition comprising a crosslinked product having a crosslinking degree of 50% or more and comprising an ethylene-α-olefin copolymer and an olefin-based resin, and a thermoplastic elastomer added later.

[0005] Furthermore, Patent Document 3 discloses a polymer composition in which polyphenylene ether is blended into a thermoplastic cross-linked rubber composition, wherein the thermoplastic cross-linked rubber composition is a cross-linked composition containing a cross-linkable rubber-like polymer and a thermoplastic resin which is an olefin resin and / or a styrene resin.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: International Publication No. 2010 / 067564 Pamphlet

[0009] Patent Document 2: International Publication No. 00 / 061681 Pamphlet

[0010] Patent Document 3: Japanese Patent Application Publication No. 2008-007589 Summary of the invention

[0011] Problems to be solved by the invention

[0012] However, in recent years, thermoplastic elastomer compositions used for automobile interior materials that require a soft touch have been required to have further improved scratch resistance and to be able to form an appearance with lower gloss.

[0013] In view of the above requirements, the compositions described in Patent Documents 1, 2, and 3 still have room for improvement in terms of the balance between scratch resistance and formation of a low-gloss appearance.

[0014] The present disclosure provides a thermoplastic elastomer composition suitable for obtaining a molded product having excellent scratch resistance and capable of forming a low-gloss appearance. In addition, the present disclosure provides a method for producing a thermoplastic elastomer composition having excellent scratch resistance and capable of forming a low-gloss appearance.

[0015] Means for solving problems

[0016] That is, the present disclosure relates to the following [1] to [6].

[0017] [1] A thermoplastic elastomer composition comprising the following first composition and the following second composition,

[0018] The first composition is a composition comprising an olefin resin (A), an ethylene-α-olefin copolymer (B) and a crosslinking agent (F),

[0019] The second composition is a composition containing a hydrogenated product (C) of a block copolymer, wherein the block copolymer has at least one block mainly composed of conjugated diene monomer units and at least one block mainly composed of vinyl aromatic monomer units, wherein the content of the hydrogenated product (C) contained in the second composition is 30 parts by mass or more relative to 100 parts by mass of the olefin-based resin (A) contained in the thermoplastic elastomer composition.

[0020] The content of the ethylene-α-olefin copolymer (B) contained in the thermoplastic elastomer composition is 10 to 180 parts by mass based on 100 parts by mass of the olefin-based resin (A).

[0021] The content of the hydrogenated product (C) of the block copolymer contained in the thermoplastic elastomer composition is 170 to 500 parts by mass based on 100 parts by mass of the olefin resin (A), wherein the block copolymer has at least one block mainly composed of a conjugated diene monomer unit and at least one block mainly composed of a vinyl aromatic monomer unit.

[0022] When the sum of the content of the ethylene-α-olefin copolymer (B) and the content of the hydrogenated product (C) contained in the thermoplastic elastomer composition is W0 (mass %) and the gel content is W1 (mass %), the ratio W1 / W0 is 0.01 to 0.70.

[0023] [2] The thermoplastic elastomer composition according to item [1], wherein the hydrogenated product (C) is a styrene-based block copolymer.

[0024] [3] The thermoplastic elastomer composition according to item [1] or [2], wherein the content of the hydrogenated product (C) contained in the thermoplastic elastomer composition is 180 to 250 parts by mass based on 100 parts by mass of the olefin-based resin (A).

[0025] [4] The thermoplastic elastomer composition according to any one of items [1] to [3], wherein the first composition is prepared by melt-kneading the olefin resin (A), the ethylene-α-olefin copolymer (B) and the crosslinking agent (F);

[0026] The thermoplastic elastomer composition is prepared by melt-kneading the first composition and the second composition.

[0027] [5] A method for producing a thermoplastic elastomer composition, comprising the steps of (i) or (ii),

[0028] (i) a step of dynamically crosslinking an olefin resin (A) and an ethylene-α-olefin copolymer (B) using a crosslinking agent (F), adding a hydrogenated product (C) to the latter stage of the same extruder, melt-kneading the mixture, and then taking out a thermoplastic elastomer composition from the extruder,

[0029] (ii) a step of dynamically crosslinking an olefin resin (A) and an ethylene-α-olefin copolymer (B) using a crosslinking agent (F), taking out the crosslinked product from an extruder after the crosslinking reaction is completed, and remelting and extruding the crosslinked product and the hydrogenated product (C) to obtain a thermoplastic elastomer composition,

[0030] The content of the ethylene-α-olefin copolymer (B) contained in the thermoplastic elastomer composition is 10 to 180 parts by mass based on 100 parts by mass of the olefin-based resin (A).

[0031] The content of the hydrogenated product (C) contained in the thermoplastic elastomer composition is 170 to 500 parts by mass based on 100 parts by mass of the olefin-based resin (A).

[0032] When the sum of the content of the ethylene-α-olefin copolymer (B) and the content of the hydrogenated product (C) contained in the thermoplastic elastomer composition is W0 (mass %) and the gel content is W1 (mass %), the ratio W1 / W0 is 0.01 to 0.70.

[0033] [6] An instrument panel surface comprising the composition described in item [1].

[0034] Effects of the Invention

[0035] According to the present disclosure, a thermoplastic elastomer composition having excellent scratch resistance and capable of forming a low-gloss appearance can be provided. In addition, according to the present disclosure, a method for producing a thermoplastic elastomer composition having excellent scratch resistance and capable of forming a low-gloss appearance can be provided. DETAILED DESCRIPTION

[0036] In the present disclosure, the description of “XX or more and YY or less” and “XX to YY” indicating a numerical range means a numerical range including the lower limit and the upper limit as endpoints unless otherwise specified.

[0037] Moreover, when describing a numerical range in stages, the upper limit and the lower limit of each numerical range can be arbitrarily combined.

[0038] In addition, the description of "A and / or B" is a concept including the case of A, the case of B, and the case of both A and B.

[0039] <Olefin resin (A)>

[0040] The olefin resin (A) [hereinafter sometimes referred to as "component (A)"] as one of the components contained in the first composition in the thermoplastic elastomer composition of the present disclosure is not particularly limited as long as it is a crystalline polymer (resin) obtained from an olefin, but is preferably a polymer formed from a crystalline high molecular weight solid product obtained by polymerizing one or more olefins by either a high pressure method or a low pressure method.

[0041] The olefin-based resin (A) may be used alone or in combination of two or more.

[0042] Examples of olefins as raw materials of component (A) of the present disclosure include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 2-methyl-1-propylene, 3-methyl-1-pentene, 4-methyl-1-pentene, 5-methyl-1-hexene, etc. These olefins may be used alone or in combination of two or more.

[0043] Among these olefin-based resins (A), propylene-based polymers are preferred from the viewpoint of heat resistance and oil resistance.

[0044] The propylene-based polymer disclosed herein refers to a polymer in which the content of the constituent unit derived from propylene in the constituent units constituting the polymer is 50 mol% or more, and the content of the constituent unit derived from propylene in the component (A) is preferably 90 mol% or more.

[0045] The propylene-based polymer disclosed in the present invention may be one kind or two or more kinds.

[0046] The propylene-based polymer disclosed in the present invention may be a propylene homopolymer or a copolymer of propylene and a comonomer other than propylene, but is preferably a propylene homopolymer.

[0047] The structure of the propylene-based polymer disclosed in the present invention is not particularly limited, for example, the constituent unit portion derived from propylene may be an isotactic structure, a syndiotactic structure, or an atactic structure. In addition, in the case of the above-mentioned copolymer, it may be any of a random type (also referred to as random PP), a block type (also referred to as block PP: bPP), or a graft type.

[0048] As the above-mentioned comonomer, any other monomer copolymerizable with propylene may be used, and α-olefins having 2 or 4 to 10 carbon atoms are preferred. Specifically, ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, etc. may be mentioned, among which ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene are preferred. The comonomer may be used alone or in combination of two or more.

[0049] The content of the structural unit derived from the comonomer in the copolymer is preferably 10 mol% or less from the viewpoint of flexibility and the like.

[0050] The propylene polymer disclosed in the present invention can be synthesized by a conventionally known method, or a commercially available product can be used. Examples of commercially available products include polypropylene from SunAllomer Co., Ltd., PrimePolypro from Prime Polymer Co., Ltd., Novatec from Japan Polypropylene Co., Ltd., and SCG PP from SCG Plastics Co., Ltd.

[0051] The propylene polymer disclosed in the present invention may be a crystalline polymer or a non-crystalline polymer. Here, crystallinity means that a melting point (Tm) can be observed in differential scanning calorimetry (DSC).

[0052] When the propylene polymer disclosed in the present invention is a crystalline polymer, its melting point (measured in accordance with JIS K 7121) is preferably 100° C. or higher, more preferably 120° C. or higher, and preferably 180° C. or lower, more preferably 170° C. or lower, from the viewpoint of heat resistance and the like.

[0053] The MFR (measured in accordance with ASTM D1238-65T, 230°C, 2.16 kg load) of the component (A) of the present disclosure is preferably 0.1 to 100 g / 10 min, more preferably 0.1 to 50 g / 10 min.

[0054] When the MFR of the component (A) of the present disclosure is within the above range, a composition excellent in heat resistance, mechanical strength, fluidity, and moldability can be easily obtained.

[0055] <Ethylene-α-olefin copolymer (B)>

[0056] The ethylene-α-olefin copolymer (B) which is one of the components contained in the first composition in the thermoplastic elastomer composition of the present disclosure is an ethylene-α-olefin copolymer containing units derived from ethylene and units derived from α-olefin.

[0057] The ethylene-α-olefin copolymer (B) disclosed herein [hereinafter sometimes referred to as "component (B)"] can be obtained by copolymerizing at least ethylene and an α-olefin. The carbon number of the α-olefin is not particularly limited, but is preferably 3 to 20.

[0058] Examples of the 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 them, from the viewpoint of imparting flexibility, α-olefins having 5 to 12 carbon atoms are preferred, propylene, 1-butene, and 1-octene are more preferred, and 1-octene is further preferred.

[0059] Regarding the component (B) of the present disclosure, generally, the unit derived from ethylene is in the range of 70 to 99 mol%, preferably in the range of 80 to 97 mol%, and the unit derived from α-olefin is in the range of 1 to 30 mol%, preferably in the range of 3 to 20 mol% (wherein the total amount of the unit derived from ethylene and the unit derived from α-olefin is 100 mol%). It is preferred that the content ratio of the unit derived from ethylene is within the above range in order to obtain a thermoplastic elastomer composition having excellent mechanical strength.

[0060] As required, a monomer having an unsaturated bond can be copolymerized with the component (B) of the present disclosure. Examples of monomers having an unsaturated bond include conjugated dienes such as butadiene and isoprene, non-conjugated dienes such as 1,4-hexadiene, cyclic diene compounds such as dicyclopentadiene and norbornene derivatives, and acetylenes. Among them, ethylidene norbornene (ENB) and dicyclopentadiene (DCPD) are more preferred from the viewpoint of flexibility.

[0061] The MFR (ASTM D1238 load 2.16 kg, temperature 190° C.) of the component (B) of the present disclosure is usually in the range of 0.1 to 20 g / 10 min, preferably in the range of 0.3 to 10 g / 10 min.

[0062] By adopting an MFR within the above range, it is possible to obtain a thermoplastic elastomer composition having a better balance between fluidity and mechanical strength.

[0063] The density of the component (B) of the present disclosure is usually 0.8 to 0.9 g / cm 3 range.

[0064] The component (B) disclosed in the present invention can be manufactured using known polymerization catalysts such as Ziegler-Natta catalysts, vanadium catalysts, and metallocene catalysts. The polymerization method is not particularly limited, and can be carried out by liquid phase polymerization methods such as solution polymerization, suspension polymerization, and bulk polymerization, gas phase polymerization, and other known polymerization methods. In addition, these copolymers are not limited as long as they have the effect of the present invention, and can also be obtained as commercial products. As commercial products, for example, they can include: trade name ENGAGE8842 (ethylene-1-octene copolymer) manufactured by Dow Chemical Company, Vistalon (registered trademark) manufactured by ExxonMobil Corporation, ESPRENE (registered trademark) manufactured by Sumitomo Chemical (Strain), Mitsui EPT (registered trademark) manufactured by Mitsui Chemical (Strain), TAFMER P (registered trademark), TAFMER A (registered trademark), etc.

[0065] <Crosslinking agent (F)>

[0066] The crosslinking agent (F) as one of the components contained in the first composition in the thermoplastic elastomer composition of the present disclosure is not particularly limited as long as it is a compound capable of crosslinking the ethylene-α-olefin copolymer (B), but is preferably an organic peroxide.

[0067] Specific examples of organic peroxides include 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-hexylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclododecane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)octane, n-butyl-4,4-dihydro-1,4-bis(tert-butylperoxy)octane, Peroxyketals such as (tert-butylperoxy)butane, n-butyl-4,4-bis(tert-butylperoxy)valerate; di-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide, α,α'-bis(tert-butylperoxym-isopropyl)benzene, α,α'-bis(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, ) dialkyl peroxides such as hexyne-3; diacyl peroxides such as acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-methylbenzoyl peroxide; tert-butyl peroxyacetate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxylaurate, Peroxy esters such as tert-butyl benzoate, di-tert-butyl peroxyisophthalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, tert-butyl peroxymaleate, tert-butyl peroxyisopropyl carbonate, and cumyl peroxyoctanoate; hydrogen peroxides such as tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide, etc.

[0068] Among these components (F), 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, di-tert-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3 are preferred from the viewpoints of thermal decomposition temperature and crosslinking performance.

[0069] The component (F) of the present disclosure may be used alone or in combination of two or more.

[0070] When the thermoplastic elastomer composition of the present disclosure contains the component (F), it is preferred to use the following crosslinking aid in combination.

[0071] 〈Crosslinking aid (G)〉

[0072] The crosslinking aid (G) disclosed in the present invention may include various known crosslinking aids, and specifically, may include monofunctional monomers and polyfunctional monomers. Such a crosslinking aid can control the crosslinking reaction rate.

[0073] As the monofunctional monomer, for example, free radical polymerizable vinyl monomers are preferred, and examples thereof include aromatic vinyl monomers, unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile, acrylate monomers, methacrylate monomers, acrylic acid monomers, methacrylic acid monomers, maleic anhydride monomers, and N-substituted maleimide monomers.

[0074] As a specific example of a monofunctional monomer, for example, styrene, methyl styrene, chloromethyl styrene, hydroxy styrene, tert-butoxy styrene, acetoxy styrene, 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, methyl maleic anhydride, 1,2-dimethyl maleic anhydride, ethyl maleic anhydride, phenyl maleic anhydride, N-methyl maleimide, N-ethyl maleimide, N-cyclohexyl maleimide, N-lauryl maleimide, N-hexadecyl maleimide, etc. can be cited. Among them, from the viewpoint of ease of reaction and versatility, styrene, acrylonitrile, methacrylonitrile, methyl acrylate, maleic anhydride, N-methyl maleimide, etc. are preferred. These monofunctional monomers can be used alone or in combination of two or more.

[0075] The polyfunctional monomer is a monomer having a plurality of free radical polymerizable functional groups as functional groups, and is preferably a monomer having a vinyl group. The number of functional groups of the polyfunctional monomer is preferably 2 or 3.

[0076] Specific examples of the multifunctional monomer 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-tolylene dimaleimide, diallyl phthalate, tetraallyloxyethane, 1,2-polybutadiene, and more preferably divinylbenzene and triallyl isocyanurate. These multifunctional monomers may be used alone or in combination of two or more.

[0077] <Hydrogenated Block Copolymer (C)>

[0078] The hydrogenated product (C) of the block copolymer contained in the second composition of the thermoplastic elastomer composition of the present disclosure [hereinafter sometimes referred to as "ingredient (C)", "hydrogenated product (C)" or "hydrogenated product (C)"] is a hydrogenated product of a block copolymer having at least one block mainly composed of conjugated diene monomer units and at least one block mainly composed of vinyl aromatic monomer units.

[0079] The component (C) of the present disclosure is obtained by hydrogenating (hereinafter sometimes referred to as “hydrogenation”) at least a part of the monomer units derived from the conjugated diene monomer.

[0080] Here, the "vinyl aromatic monomer unit" refers to a constituent unit of a polymer produced by polymerizing a vinyl aromatic compound as a 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. In addition, the "conjugated diene monomer unit" refers to a constituent unit of a polymer produced by polymerizing a conjugated diene as a monomer, and has a molecular structure in which two carbon atoms of an olefin derived from a conjugated diene monomer serve as bonding sites.

[0081] In the component (C) of the present disclosure, "as the main component" means that in the copolymer block, the monomer units derived from the conjugated diene monomer (or vinyl aromatic monomer) contain 50 mol% or more, preferably 60 mol% or more, more preferably 65 mol% or more in the copolymer block. For example, a block containing conjugated diene monomer units as the main component means that the block contains 50 mol% or more, preferably 60 mol% or more, more preferably 65 mol% or more of monomer units derived from the conjugated diene monomer.

[0082] The vinyl aromatic monomer in the component (C) of the present disclosure is not particularly limited, and examples thereof 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 of two or more. Among these, styrene is preferred from the viewpoint of economic efficiency.

[0083] The conjugated diene monomer in the component (C) of the present disclosure is a diene having a pair of conjugated double bonds, and examples thereof include 1,3-butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, etc. Among them, butadiene and isoprene are preferred from the viewpoint of economic efficiency. They may be used alone or in combination of two or more.

[0084] The configuration of each block in the component (C) of the present disclosure is not particularly limited, and a suitable configuration can be appropriately adopted. For example, when S represents a polymer block composed of vinyl aromatic monomer units, and B represents a polymer block composed of units in which at least a portion of conjugated diene monomer units are hydrogenated, the hydrogenated product of the block copolymer can be SB, S (BS) n1 (Here, n1 represents an integer from 1 to 3), S (BSB) n2 (herein, n2 represents an integer of 1 to 2) etc., a linear block copolymer represented by (SB) n3 A copolymer represented by X (where n3 is an integer of 3 to 6. X is a coupling agent residue such as silicon tetrachloride, tin tetrachloride, or a polyepoxide). Among them, preferred are linear block copolymers of type 2 (diblock) of SB, type 3 (triblock) of SBS, and type 4 (tetrablock) of SBSB.

[0085] Here, the polymer block B may be a polymer block consisting only of conjugated diene monomer units, or a polymer block containing conjugated diene monomer units as the main body and containing vinyl aromatic monomer units (copolymerized conjugated diene monomer units and vinyl aromatic monomer units). In any polymer block, at least a portion of the conjugated diene monomer units are hydrogenated.

[0086] The content of the vinyl aromatic monomer unit in the component (C) disclosed herein is 10 to 80% by mass, preferably 12 to 80% by mass, and more preferably 12 to 70% by mass from the viewpoint of heat resistance and dispersibility. By making the content of the vinyl aromatic monomer unit 10% by mass or more, the mechanical properties are further improved, and by making it 80% by mass or less, the low temperature characteristics can be further improved.

[0087] The content of the vinyl aromatic monomer unit in the component (C) of the present disclosure can be measured by nuclear magnetic resonance spectroscopy (NMR).

[0088] From the viewpoint of mechanical strength, the content of the vinyl aromatic monomer unit block in the component (C) of the present disclosure is preferably 10% by mass or more, and more preferably 10 to 40% by mass. Here, the content of the vinyl aromatic compound polymer block in the component (C) is defined by the following formula using the mass of the vinyl aromatic compound polymer block obtained by the following method (here, the vinyl aromatic compound polymer having an average degree of polymerization of about 30 or less is excluded), wherein the method is a method of oxidatively decomposing the copolymer before hydrogenation using tert-butyl hydroperoxide using osmium tetroxide as a catalyst (the method described in IM Kolthoff, et al., J. Polym. Sci. 1429 (1946), hereinafter also referred to as "osmium tetroxide decomposition method").

[0089] Content of the vinyl aromatic compound polymer block (mass %) = (mass of the vinyl aromatic compound polymer block in the copolymer before hydrogenation / mass of the copolymer before hydrogenation) × 100

[0090] In the case where there are multiple polymer blocks in the component (C) of the present disclosure, the structures such as the molecular weight and composition of each may be the same or different. For example, in the component (C), there may also be hydrogenated copolymer blocks comprising conjugated diene monomer units and vinyl aromatic monomer units and hydrogenated copolymer blocks with conjugated diene monomer units as the main body. The boundaries and ends of each block do not necessarily need to be clearly distinguished. The distribution mode of the vinyl aromatic monomer units in each polymer block is not particularly limited, and may be uniformly distributed, or may be distributed in a cone, step, convex or concave shape. In addition, a crystalline portion may be present in the polymer block.

[0091] The distribution mode of the vinyl units of the conjugated diene monomer units in each polymer block in the component (C) disclosed in the present invention is not particularly limited, for example, the distribution may also be biased. As methods for controlling the distribution of the vinyl units, there may be cited a method of adding a vinylating agent during polymerization, a method of changing the polymerization temperature, etc. In addition, the distribution of the hydrogenation rate of the conjugated diene monomer units may also be biased. The distribution of the hydrogenation rate can be controlled by the following methods: a method of changing the distribution of the vinyl units; after copolymerizing isoprene and butadiene, hydrogenating them using a hydrogenation catalyst described later, a method of utilizing the difference in hydrogenation rates between the isoprene unit and the butadiene unit, etc.

[0092] Regarding component (C) of the present disclosure, from the viewpoint of heat resistance, aging resistance and weather resistance, preferably 75 mol % or more of the unsaturated bonds contained in the conjugated diene monomer units before hydrogenation are hydrogenated, more preferably 85 mol % or more, and further preferably 97 mol % or more.

[0093] The hydrogenation catalyst used for hydrogenation is not particularly limited and has been conventionally known.

[0094] The following catalysts can be used:

[0095] (1) A supported heterogeneous hydrogenation catalyst obtained by supporting a metal such as Ni, Pt, Pd, or Ru on carbon, silica, alumina, diatomaceous earth, or the like;

[0096] (2) a so-called Ziegler-type hydrogenation catalyst using an organic acid salt of Ni, Co, Fe, Cr or the like or a transition metal salt such as acetylacetonate and a reducing agent such as an organic aluminum,

[0097] (3) Homogeneous hydrogenation catalysts such as so-called organometallic complexes such as organometallic compounds of Ti, Ru, Rh, Zr, etc.

[0098] As specific hydrogenation catalysts, those described in JP-B 42-008704, JP-B 43-006636, JP-B 63-004841, JP-B 01-037970, JP-B 01-053851, JP-B 02-009041, etc. can be used. Among them, preferred hydrogenation catalysts include reducing organometallic compounds such as titanocene compounds.

[0099] As the titanocene compound, for example, the compounds described in Japanese Patent Gazette No. 08-109219 can be used. As specific examples, there can be cited compounds having at least one ligand having a (substituted) cyclopentadienyl skeleton, indenyl skeleton or fluorenyl skeleton, such as bis(cyclopentadienyl)titanium dichloride and mono(pentamethylcyclopentadienyl)titanium trichloride.

[0100] Examples of the reducing organometallic compound include organoalkali metal compounds such as organolithium, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds.

[0101] The polymerization method of the block copolymer before hydrogenation in the component (C) of the present disclosure is not particularly limited, and a known method may be used. For example, methods described in Japanese Patent Publication No. 36-019286, Japanese Patent Publication No. 43-017979, Japanese Patent Publication No. 46-032415, Japanese Patent Publication No. 49-036957, Japanese Patent Publication No. 48-002423, Japanese Patent Publication No. 48-004106, Japanese Patent Publication No. 56-028925, Japanese Patent Publication No. 59-166518, Japanese Patent Publication No. 60-186577, etc. may be cited.

[0102] As required, component (C) may have a polar group. As the polar group, for example, a hydroxyl group, a carboxyl group, a carbonyl group, a thiocarbonyl group, an acyl halide group, an acid anhydride group, a thiocarboxylic acid group, an aldehyde group, a thioaldehyde group, a carboxylate 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 cyano group, a pyridyl group, a quinolyl group, an epoxy group, a thioepoxy group, a thioether group, an isocyanate group, an isothiocyanate group, a halogenated silicon group, an alkoxysilyl group, a halogenated tin group, a boric acid group, a boron-containing group, a borate group, an alkoxytin group, a phenyltin group, etc. can be cited.

[0103] The vinyl bond content in the conjugated diene monomer unit in the block copolymer before hydrogenation in the component (C) of the present disclosure is preferably 5 mol% or more from the viewpoint of flexibility and scratch resistance, and preferably 90 mol% or less from the viewpoint of productivity, elongation at break and scratch resistance. The vinyl bond content in the conjugated diene monomer unit is more preferably 10 to 90 mol%, more preferably 10 to 80 mol%. The vinyl bond content mentioned here refers to the proportion of vinyl bonds incorporated in the conjugated diene before hydrogenation in the form of 1,2-bonds, 3,4-bonds and 1,4-bonds. The vinyl bond content can be determined by NMR.

[0104] The weight average molecular weight of the component (C) before cross-linking is not particularly limited, but from the viewpoint of scratch resistance, it is preferably 50,000 or more, from the viewpoint of molding fluidity, it is preferably 400,000 or less, and more preferably 50,000 to 300,000. The molecular weight distribution (Mw / Mn: weight average molecular weight / number average molecular weight) is not particularly limited, and from the viewpoint of scratch resistance, it is preferably a value close to 1. The weight average molecular weight and the number average molecular weight can be obtained by gel permeation chromatography (GPC; manufactured by Shimadzu Corporation, device name "LC-10"), column: TSKgelGMHXL (4.6 mmID×30 cm, 2 roots) using tetrahydrofuran (1.0 mL / min) as a solvent at an oven temperature of 40°C. The weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) are calculated as polystyrene-converted molecular weights.

[0105] The component (C) disclosed herein is not particularly limited, and the above-mentioned conjugated diene monomers and vinyl aromatic monomers can be used. Among them, from the viewpoint of the balance between mechanical strength and impact resistance, a block containing a butadiene unit and a styrene unit, a block containing an isoprene unit and a styrene unit, etc. can be cited as a preferred combination.

[0106] The component (C) disclosed herein only needs to contain at least a conjugated diene monomer unit as the main body, and the content of each monomer is not particularly limited. In particular, from the viewpoint of the balance between mechanical strength and impact resistance, the content of the vinyl aromatic monomer unit in the copolymer block is preferably 10% by mass or more and less than 80% by mass, and more preferably 10% by mass or more and less than 70% by mass.

[0107] As commercially available products of the component (C) of the present disclosure, for example, SOES1605 and S1606 manufactured by Asahi Kasei Corporation, and Tuftec H1041 and H1221 manufactured by Asahi Kasei Corporation (all are registered trademarks), etc. can be used.

[0108] <Softener (D)>

[0109] The softener (D) [hereinafter, sometimes referred to as "component (D)"] as one of the components that may be included in the thermoplastic elastomer composition, the first composition and / or the second composition of the present invention is not particularly limited, and a plasticizer generally used for rubber can be used. From the viewpoint of compatibility with the above-mentioned propylene polymer (A) and ethylene-α-olefin copolymer (B), etc., process oils composed of hydrocarbons such as paraffin, cycloparaffin, and aromatic are preferred. Among these components (D), process oils mainly composed of paraffin hydrocarbons are preferred from the viewpoint of weather resistance and colorability, and process oils mainly composed of cycloparaffin hydrocarbons are preferred from the viewpoint of compatibility. From the viewpoint of heat and light stability, the content of aromatic hydrocarbons in the process oil is preferably 10% or less, more preferably 5% or less, and further preferably 1% or less, based on the carbon atom ratio specified in ASTM D2140-97.

[0110] <Polyorganosiloxane (E)>

[0111] The structure of the polyorganosiloxane (E) [hereinafter sometimes referred to as "component (E)"] which is one of the components that may be included in the thermoplastic elastomer composition, the first composition and / or the second composition of the present disclosure is not particularly limited, but preferably has a linear, branched or cross-linked polymer structure from the viewpoint of abrasion resistance and hand feel.

[0112] The component (E) disclosed herein is not particularly limited, and known components may be used. Preferred polyorganosiloxanes are polymers containing siloxane units having substituents such as alkyl, vinyl, and aryl groups, among which polyorganosiloxanes having alkyl groups are particularly preferred, and polyorganosiloxanes having methyl groups are more preferred.

[0113] Specific examples of the polyorganosiloxane having a methyl group include polydimethylsiloxane, polymethylphenylsiloxane, polymethylhydrogensiloxane, etc. Among them, polydimethylsiloxane is preferred.

[0114] The kinematic viscosity of the component (E) of the present disclosure is not particularly limited, but from the viewpoint of wear resistance and scratch resistance, the kinematic viscosity (25° C.) specified in JIS Z8803 is preferably 5000 centistokes (cSt) or more. In addition, from the viewpoint that the dispersibility of the component (E) in the obtained thermoplastic elastomer composition tends to be improved, the appearance is excellent, and the quality stability during melt extrusion tends to be further improved, the kinematic viscosity of the component (E) is preferably less than 3 million cSt. The kinematic viscosity of the component (E) is more preferably 10,000 cSt or more and less than 3 million cSt, and further preferably 50,000 cSt or more and less than 3 million cSt.

[0115] <Thermoplastic Elastomer Composition>

[0116] The thermoplastic elastomer composition disclosed herein is a thermoplastic elastomer composition comprising the following first composition and the following second composition,

[0117] The content of the component (B) in the thermoplastic elastomer composition is 10 to 180 parts by mass based on 100 parts by mass of the component (A).

[0118] The content of the component (C) contained in the thermoplastic elastomer composition is 170 to 500 parts by mass based on 100 parts by mass of the component (A).

[0119] When the sum of the content of component (B) and the content of component (C) in the thermoplastic elastomer composition is W0 (mass %) and the gel content is W1 (mass %), the value of the ratio (W1 / W0) is 0.01 to 0.70. The value of W1 / W0 is preferably 0.10 to 0.60, and more preferably 0.20 to 0.50.

[0120] The value of W1 / W0 can be adjusted by changing the composition of the first composition and the second composition included in the thermoplastic elastomer composition of the present disclosure, and can be greatly changed by the content of the component (C) in the first composition and the content of the component (F) in the second composition. The details will be described later.

[0121] The thermoplastic elastomer composition of the present disclosure has a Shore A hardness (10 seconds value) (measurement method in accordance with JIS K6253) of preferably 40 to 90, more preferably 50 to 85, and even more preferably 60 to 85.

[0122] When the Shore A hardness (10 seconds value) of the thermoplastic elastomer composition of the present disclosure is within the above range, a molded article having a good touch, a high-grade appearance, or other appearance, and scratch resistance can be easily formed.

[0123] Specifically, the Shore A hardness (10 seconds value) can be measured by the method described in the following Examples.

[0124] From the viewpoint of obtaining a composition with excellent moldability, the melt flow rate of the thermoplastic elastomer composition of the present disclosure (measured in accordance with JIS K 7210, 230° C., 2.16 kg load) is preferably 0.5 to 300 g / 10 min, more preferably 1 to 200 g / 10 min, and even more preferably 2 to 200 g / 10 min.

[0125] The content of the component (B) in the thermoplastic elastomer composition of the present disclosure is 10 to 180 parts by mass, preferably 20 to 175 parts by mass, more preferably 50 to 170 parts by mass, and even more preferably 80 to 170 parts by mass, based on 100 parts by mass of the component (A).

[0126] If the content of the component (B) is less than 10 parts by mass based on 100 parts by mass of the component (A), a preferred appearance (gloss) cannot be obtained. On the other hand, if it exceeds 180 parts by mass, sufficient fluidity cannot be obtained.

[0127] The content of the component (C) in the thermoplastic elastomer composition of the present disclosure is 170 to 500 parts by mass, preferably 175 to 400 parts by mass, and more preferably 180 to 250 parts by mass, based on 100 parts by mass of the component (A).

[0128] If the content of component (C) is less than 170 parts by mass relative to 100 parts by mass of component (A), the thermoplastic elastomer may not have a preferred scratch resistance. On the other hand, if it exceeds 500 parts by mass, a thermoplastic elastomer having a preferred appearance (gloss) and sufficient heat resistance may not be obtained.

[0129] The First Composition

[0130] The first composition contained in the thermoplastic elastomer composition of the present disclosure is a composition containing the above-mentioned olefin resin (A), the above-mentioned ethylene-α-olefin copolymer (B) and the above-mentioned crosslinking agent (F). The first composition may contain component (D) and component (E) and other additives described below within the range that does not affect the effects of the present disclosure.

[0131] The content of the component (F) contained in the first composition of the present disclosure is preferably 0.2 to 3.0 parts by mass, more preferably 0.3 to 2.0 parts by mass, and even more preferably 0.4 to 1.5 parts by mass, relative to 100 parts by mass of the component (A).

[0132] The first composition of the present disclosure may also contain a crosslinking aid (G) as needed. The crosslinking aid may be any known crosslinking aid, for example, divinylbenzene may be used. The content of the crosslinking aid (G) is preferably 0.5 to 10.0 parts by mass, more preferably 1.0 to 5.0 parts by mass, relative to 100 parts by mass of component (A).

[0133] The first composition of the present disclosure may contain the above-mentioned component (C) in an amount such that the value of W1 / W0 is 0.70 or less, but preferably substantially contains no component (C), and more preferably contains no component (C). When the content of the component (C) in the first composition increases, there is a tendency for the value of W1 / W0 to increase, and when the value of W1 / W0 exceeds 0.70, the desired scratch resistance cannot be obtained.

[0134] The Second Composition

[0135] The second composition contained in the thermoplastic elastomer composition of the present disclosure is a composition containing the above-mentioned component (C).

[0136] The content of the component (C) contained in the second composition is 30 parts by mass or more, preferably 80 parts by mass or more, and more preferably 100 parts by mass or more, based on 100 parts by mass of the olefin-based resin (A) contained in the thermoplastic elastomer composition.

[0137] The upper limit is not particularly limited as long as it does not exceed 500 parts by mass based on 100 parts by mass of the olefin-based resin (A) contained in the thermoplastic elastomer composition.

[0138] The second composition of the present disclosure may contain the above-mentioned component (F) in an amount of 0 to 5 parts by mass relative to 100 parts by mass of component (C). Here, the content of component (F) in the range of 0 to 5 parts by mass means that component (F) may be contained or not contained, but even if contained, it is 5 parts by mass or less.

[0139] In addition, the second composition preferably does not substantially contain component (F), and more preferably does not contain component (F). When the content of component (F) in the second composition exceeds 5 parts by mass, there is a tendency for the value of W1 / W0 to become high, and when the value of W1 / W0 exceeds 0.70, the obtained thermoplastic elastomer cannot obtain the desired scratch resistance.

[0140] When the thermoplastic elastomer composition of the present disclosure contains the above-mentioned component (D) and the above-mentioned component (E) in addition to the above-mentioned component (A) and the like, from the viewpoint of moldability and heat resistance, the content of the component (D) is 0 to 300 parts by mass, preferably 10 to 250 parts by mass, more preferably 20 to 200 parts by mass, and the content of the component (E) is within the range of 2 to 40 parts by mass, more preferably 4 to 35 parts by mass, and even more preferably 5 to 30 parts by mass, based on 100 parts by mass of the component (A).

[0141] When the content of the component (E) is 2 parts by mass or more, the effect of improving the scratch resistance of the obtained thermoplastic elastomer composition is sufficiently exhibited, and when it is 40 parts by mass or less, the dispersibility in the thermoplastic elastomer composition is excellent.

[0142] As long as the thermoplastic elastomer composition of the present disclosure contains the component (D) and the component (E) of the present disclosure, they may be contained in the first composition, the second composition, or may be the third component.

[0143] Furthermore, the second composition may contain the component (A), the component (B), the component (G), and other additives described below within a range not impairing the effects of the present disclosure.

[0144] The thermoplastic elastomer composition of the present disclosure may contain an inorganic filler, a plasticizer, and other additives in addition to the above-mentioned component (A) and the like.

[0145] Furthermore, as long as these inorganic fillers, plasticizers, and other additives are contained in the thermoplastic elastomer composition of the present disclosure, they may be contained in the first composition, may be contained in the second composition, or may be the third component.

[0146] Examples of the inorganic filler include calcium carbonate, magnesium carbonate, silica, carbon black, glass fiber, titanium oxide, clay, mica, talc, magnesium hydroxide, and aluminum hydroxide.

[0147] Examples of the plasticizer include polyethylene glycol and phthalate esters such as dioctyl phthalate (DOP).

[0148] Examples of other additives include organic and inorganic pigments such as carbon black, titanium dioxide, or phthalocyanine black; heat stabilizers such as 2,6-di-tert-butyl-4-methylphenol and 3-(3,5'-di-tert-butyl-4-hydroxyphenyl) propionate; antioxidants such as trisnonylphenyl phosphite and distearyl pentaerythritol diphosphite; ultraviolet light absorbers such as 2-(2'-hydroxy-5'-methylphenyl)benzotriazole and 2,4-dihydroxybenzophenone; and bis-[2,2,6,6-tetramethyl- Light stabilizers such as [4-piperidyl] sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl)-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; anti-adhesion agents such as stearamide and erucamide; foaming agents such as sodium bicarbonate and N,N'-dinitropentamethylenetetramine; antistatic agents such as palmitic acid monoglyceride and stearic acid monoglyceride; antibacterial agents such as silver ion-loaded zeolite and silver thiosulfate complex, etc.

[0149] Furthermore, the thermoplastic elastomer composition of the present disclosure may also contain a biomass-derived raw material.

[0150] <Method for producing thermoplastic elastomer>

[0151] The method for producing a thermoplastic elastomer disclosed in the present invention may have the following steps. That is, the method for producing a thermoplastic elastomer disclosed in the present invention may have:

[0152] (i) a step of dynamically crosslinking an olefin resin (A) and an ethylene-α-olefin copolymer (B) using a crosslinking agent (F), adding a hydrogenated product (C) in the latter stage of the same extruder, further adding other components as required, melt-kneading, and then taking out the composition of the present disclosure from the extruder, or

[0153] (ii) A process of dynamically crosslinking an olefin resin (A) and an ethylene-α-olefin copolymer (B) using a crosslinking agent (F), taking out the crosslinked product from an extruder after the crosslinking reaction is completed, and remelting and extruding the crosslinked product and the hydrogenated product (C) to obtain the composition of the present invention.

[0154] The content of the ethylene-α-olefin copolymer (B) contained in the obtained thermoplastic elastomer composition is 10 to 180 parts by mass based on 100 parts by mass of the olefin-based resin (A).

[0155] The content of the hydrogenated product (C) contained in the obtained thermoplastic elastomer composition is 170 to 500 parts by mass based on 100 parts by mass of the olefin-based resin (A).

[0156] In addition, during the dynamic crosslinking reaction, the crosslinking agent (F) may be added together with the olefin resin (A) and the ethylene-α-olefin copolymer (B) from the beginning, or may be added midway in the extruder. In addition, the softener (D) may be added midway in the extruder, or may be added separately at the beginning and midway. Alternatively, a portion of the olefin resin (A) and the ethylene-α-olefin copolymer (B) may be added midway in the extruder.

[0157] Here, the degree of crosslinking is controlled by the type and amount of the crosslinking initiator and the crosslinking auxiliary, the reaction temperature and the reaction method.

[0158] In the manufacturing method disclosed herein, the Banbury mixer, kneader, single screw extruder, twin screw extruder and other general devices used in the manufacture of common resin combination and rubber composition can be adopted. In order to efficiently realize dynamic crosslinking, it is particularly preferred to use a twin screw extruder. The twin screw extruder is more suitable for making olefin resin (A) and ethylene-α-olefin copolymer (B) uniformly and finely dispersed, and then adding other components, producing a crosslinking reaction, and continuously manufacturing the composition disclosed herein.

[0159] 〈First process〉

[0160] The first step is a step of melt-kneading the above-mentioned component (A), the above-mentioned component (B) and the above-mentioned component (F), as well as the above-mentioned component (G), the above-mentioned component (C), the above-mentioned component (D), the above-mentioned component (E) and / or other additives as optional components in the blending amounts described above to produce a first composition.

[0161] The melt kneading in the first step is preferably carried out in a non-open device, and is preferably carried out in an inert gas atmosphere such as nitrogen or carbon dioxide. The melt kneading temperature is in the range of from the melting point of component (A) to 300°C, usually 150 to 270°C, preferably 160 to 250°C. The kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes. In addition, the applied shear force is usually 10 to 50,000 s if the shear rate is expressed. -1 The range is preferably 100 to 10,000 s. -1 within the range.

[0162] 〈Second process〉

[0163] The second step is a method for producing a thermoplastic elastomer by melt-kneading a second composition with the first composition obtained in the first step, wherein the second composition is obtained by mixing the above-mentioned component (C) and the above-mentioned component (A), the above-mentioned component (B), the above-mentioned component (D), the above-mentioned component (E), the above-mentioned component (F), the above-mentioned component (G) and / or other additives as arbitrary components in the predetermined compounding amounts described above.

[0164] In addition, the component (D), the component (E) and the like which are components other than the above components and which may be contained in the thermoplastic elastomer of the present disclosure may be blended in the above second step or in the above first step.

[0165] Another embodiment of the method for producing the thermoplastic elastomer disclosed in the present invention is a method for producing the thermoplastic elastomer comprising the following steps: a step of producing a first composition in the first step; a step of producing a second composition by mixing the component (C) in the predetermined blending amount described above, or by melt-kneading the mixture after mixing, in a step different from the second step; and a third step of melt-kneading the first composition produced in the first step and the second composition produced in the second step.

[0166] The melt-kneading in the second step may be carried out under the same conditions as those in the first step described above.

[0167] It should be noted that the component (D), component (E) and the like which are components other than the above components that may be contained in the thermoplastic elastomer of the present disclosure may be blended in the third step, the second step or the first step.

[0168] Forming

[0169] The molded article disclosed herein is not particularly limited as long as it includes the thermoplastic elastomer composition disclosed herein, and is a molded article obtained by molding using any known molding method according to the application. Examples of the molding method include stamping molding, injection molding, extrusion molding, calendaring molding, hollow molding, vacuum molding, and compression molding. From the viewpoint of productivity and the ability to easily form a complex shape, an injection molded article molded using an injection molding method is preferred.

[0170] The thermoplastic elastomer composition disclosed in the present invention has low hardness and is soft, and has excellent scratch resistance. The application is not particularly limited, but as a molded body, it is suitable for various well-known applications such as automobile parts, civil engineering / building materials, electrical / electronic parts, sanitary products, films / sheets, foams, artificial leather, etc., and can be particularly suitable for automobile parts such as automobile interior parts, and surface materials such as artificial leather.

[0171] 〈Automotive Parts〉

[0172] Examples of automobile parts to which the molded article of the present disclosure can be applied include weather strips, ceiling materials, interior trim sheets, bumper moldings, side moldings, air spoilers, air duct hoses, cup holders, handbrake handles, shift lever covers, seat adjustment knobs, fender door seals, harness grommets, rack and pinion boots, suspension cover boots, glass rails, inner waistline seals, roof rails, trunk lid seals, molded triangular window gaskets, corner moldings, glass seals, hood seals, glass rail seals, secondary seals, various gaskets, bumper parts, body panels, side fenders, glass rail seals, instrument panel skins, door skins, ceiling skins, weather strip materials, hoses, steering wheels, boots, harness covers, seat adjuster covers, and the like. Among these, the thermoplastic elastomer composition of the present disclosure is particularly preferred because it can improve the texture and touch.

[0173] 〈Civil engineering / building materials〉

[0174] Examples of civil engineering / construction materials that can use the molded article of the present invention include civil engineering materials such as foundation improvement sheets, water supply plates, and noise-proof walls, building materials, various gaskets and sheets for civil engineering / construction, waterproof materials, caulking materials, and window frames for buildings. Among them, the thermoplastic elastomer composition of the present invention is particularly preferred because it can improve the texture and feel.

[0175] 〈Electrical / electronic components〉

[0176] Examples of electric / electronic parts that can use the molded article of the present disclosure include electric / electronic parts such as wire covering materials, connectors, caps, and plugs. Among them, the thermoplastic elastomer composition of the present disclosure is particularly preferred because it can improve the texture and touch.

[0177] 〈Life-related items〉

[0178] Examples of life-related products in which the molded article of the present disclosure can be used include sports goods such as sneaker soles, ski boots, tennis rackets, snowboard bindings, and bat grips, and sundry goods such as pen grips, toothbrush handles, combs, fashion belts, various hats, and shoe insoles. Among them, the thermoplastic elastomer composition of the present disclosure is particularly preferred because it can improve the texture and feel.

[0179] 〈Film / Sheet〉

[0180] Examples of films / sheets to which the molded article of the present disclosure can be applied include infusion bags, medical containers, automobile interior and exterior materials, beverage bottles, clothing boxes, food packaging materials, food containers, retort containers, tubes, transparent substrates, sealants, and the like. Among them, the thermoplastic elastomer composition of the present disclosure is particularly preferred because it can improve the texture and feel.

[0181] 〈Artificial leather〉

[0182] Examples of artificial leathers to which the molded article of the present disclosure can be applied include chair covers, school bags, backpacks, sports shoes such as track and field shoes, marathon shoes, and running shoes, clothing such as jackets and coats, belts, straps, ribbons, notebook covers, book covers, key chains, pen cases, wallets, business card holders, commuter ticket holders, and the like. Among them, the thermoplastic elastomer composition of the present disclosure is particularly preferred because it can improve the texture and touch of the leather.

[0183] Example

[0184] Hereinafter, the present disclosure will be described in more detail based on Examples, but the present disclosure is not limited to these Examples.

[0185] In Examples and Comparative Examples, the following polymers were used.

[0186] [Olefin resin (A)]

[0187] As the olefin resin (A), a propylene homopolymer (homo PP) having a melt flow rate (MFR) of 2.0 g / 10 min at 230° C. and a load of 2.16 kg (trade name: SUNALLOMER (registered trademark) PL400A, manufactured by SunAllomer Co., Ltd.) [A-1] was used.

[0188] [Ethylene-α-olefin copolymer (B)]

[0189] As the ethylene-α-olefin copolymer (B), an ethylene-1-octene copolymer (manufactured by The Dow Chemical Company, trade name "ENGAGE 8842") [B-1] was used. The copolymer had an ethylene content of 55% by mass, an octene content of 45% by mass, and an MFR of 1.0 g / 10 min measured under the conditions of a temperature of 190° C. and a load of 2.16 kg.

[0190] [Ingredient (C)]

[0191] As the component (C), a hydrogenated product of a styrene-based block copolymer shown below was used.

[0192] (C-1) Hydrogenated styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, SOES1606 (registered trademark))

[0193] (C-2) Hydrogenated styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, SOES1605 (registered trademark))

[0194] (C-3) Hydrogenated styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, Tuftec H1041 (registered trademark))

[0195] (C-4) Hydrogenated styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, Tuftec H1221 (registered trademark))

[0196] [Softener (D)]

[0197] As the softener (D), paraffin oil (manufactured by Idemitsu Kosan Co., Ltd., trade name “Diana Process Oil PW-100”) [D-1] was used.

[0198] [Polyorganosiloxane (E)]

[0199] As the polyorganosiloxane (E), a masterbatch containing 50% by mass of dimethylsiloxane and 50% by mass of polypropylene (manufactured by DuPont Toray Specialty Materials, trade name “MB50-001”) [E-1] was used.

[0200] [Crosslinking agent (F)]

[0201] As the crosslinking agent (F), an organic peroxide: 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (manufactured by NOF Corporation, trade name “PERHEXA25B”) (F-1) was used.

[0202] [Crosslinking aid (G)]

[0203] As the crosslinking auxiliary agent (G), divinylbenzene (manufactured by Wako Pure Chemical Industries, Ltd.; hereinafter referred to as “DVB”) was used (G-1).

[0204] [Example 1]

[0205] <Manufacture of Thermoplastic Elastomer Composition>

[0206] As the extruder, a twin-screw extruder ( L / D = 74; manufactured by Kobe Steel, Ltd., "KTX-30"). As the screws, two screws having kneading sections before and after the injection port were used.

[0207] The thermoplastic elastomer composition is obtained by performing melt extrusion twice in total. (Hereinafter, the first melt extrusion is referred to as "1 Pass" and the second melt extrusion is referred to as "2 Pass".)

[0208] (1) 1Pass

[0209] Component (A-1), component (B-1), component (F-1) and component (G-1) described in Table 1 were mixed together in the amounts (parts by mass) shown in Table 1, respectively, and then introduced into a twin-screw extruder (barrel temperature: 200° C.) using a quantitative feeder and melt-extruded to obtain a first composition.

[0210] (2) 2Pass

[0211] After mixing component (C-1) and component (E-1) in the amounts (parts by mass) shown in Table 1 to prepare a second composition, the first composition obtained in the above 1 Pass was mixed and introduced into the same twin-screw extruder (barrel temperature 200°C) using a quantitative feeder, and then component (D-1) in an amount shown in Table 1 was injected from an injection port located in the center of the twin-screw extruder using a pump, and melt extrusion was performed to produce a thermoplastic elastomer composition.

[0212] <Manufacturing of Injection Molded Article>

[0213] The thermoplastic elastomer composition obtained in the above step was injection molded using an injection molding machine ["M150CL-DM" manufactured by Meiki Seisakusho Co., Ltd.] under molding conditions of a resin temperature of 220°C and a mold temperature of 40°C, using a flat mold having a size of 15 cm in length × 9 cm in width and subjected to leather grain processing, to produce an injection molded body sample.

[0214] The physical properties of the obtained thermoplastic elastomer composition and injection molded article were evaluated by the following methods.

[0215] (1) MFR (g / 10min)

[0216] The melt flow rate of the thermoplastic elastomer composition obtained above was measured under the conditions of 230° C. and 2.16 kg load in accordance with JIS K7120.

[0217] (2) Shore A hardness test

[0218] A pressed sheet having a thickness of 2 mm was prepared from the thermoplastic elastomer composition, and three pressed sheets were stacked to obtain a laminated sheet having a thickness of 6 mm, which was used as a measurement sample.

[0219] The above-mentioned measurement sample was measured using a Shore A hardness meter according to JIS K6253. After the pressurizing plate was brought into contact with the test piece, the value read 10 seconds later was defined as the Shore A hardness (10-second value).

[0220] (3) Gel content determination

[0221] The mass (W2) of the thermoplastic elastomer composition was measured, 20 mL of ODCB was added, and the mixture was heated at 145°C for 2 hours to dissolve the mixture. The mixture was hot filtered using a membrane filter, the residue on the filter was dried, and the mass (W3) of the residue after drying was measured. The gel content W1 was calculated by the following formula.

[0222] Gel content W1 (mass %) = (W3 / W2) × 100

[0223] (4) Scratch resistance

[0224] The patterned surface of the injection molded body was scratched 10 times in the longitudinal and transverse directions using a pen-type scratch hardness tester (manufactured by Erichsen, 318 / 318S No. 2) at a load of 10 N. The scratches in the central grid portion were visually observed and evaluated. The evaluation was performed according to the following criteria.

[0225] 5: There is almost no visible change in appearance caused by scratches.

[0226] 4: Slight change in appearance due to scratches is noticeable.

[0227] 3: Changes in appearance due to scratches can be observed.

[0228] 2: Changes in appearance due to scratches can be observed considerably.

[0229] 1: The appearance changes significantly due to scratches.

[0230] (5) Appearance (gloss) evaluation

[0231] The patterned surface of the injection molded article was visually observed to evaluate the gloss. The evaluation was performed according to the following criteria.

[0232] ○: Low gloss, excellent appearance.

[0233] ×: High gloss, poor appearance.

[0234] [Examples 2 to 5, Comparative Examples 1 to 4]

[0235] A thermoplastic elastomer composition and an injection molded article were obtained in the same manner as in Example 1 except that the components and their blending amounts were changed to the components and blending amounts shown in Table 1.

[0236] The physical properties of the obtained thermoplastic elastomer composition and injection molded article were evaluated by the above-mentioned methods.

[0237] Table 1

[0238]

[0239] In addition, "-" in the gel content W1 and W1 / W0 of Comparative Example 2 means that it was not measured.

[0240] <Evaluation Results>

[0241] As shown in Table 1, it can be seen that the injection molded products obtained from the thermoplastic elastomer compositions of Examples 1 to 5 were excellent in both scratch resistance and appearance.

[0242] On the other hand, the injection molded articles obtained from the thermoplastic elastomer compositions of Comparative Examples 1, 2, and 3 were not molded articles having good scratch resistance. The injection molded article obtained from the thermoplastic elastomer composition of Comparative Example 4 was not a molded article having excellent appearance.

Claims

1. A thermoplastic elastomer composition, characterized in that comprising the following first composition and the following second composition, The first composition is a composition comprising an olefin resin (A), an ethylene-α-olefin copolymer (B) and a crosslinking agent (F), The second composition is a composition containing a hydrogenated product (C) of a block copolymer, wherein the block copolymer has at least one block mainly composed of conjugated diene monomer units and at least one block mainly composed of vinyl aromatic monomer units, wherein the content of the hydrogenated product (C) contained in the second composition is 30 parts by mass or more relative to 100 parts by mass of the olefin-based resin (A) contained in the thermoplastic elastomer composition. The content of the ethylene-α-olefin copolymer (B) contained in the thermoplastic elastomer composition is 10 to 180 parts by mass based on 100 parts by mass of the olefin-based resin (A). The content of the hydrogenated product (C) of the block copolymer contained in the thermoplastic elastomer composition is 170 to 500 parts by mass based on 100 parts by mass of the olefin resin (A), wherein the block copolymer has at least one block mainly composed of a conjugated diene monomer unit and at least one block mainly composed of a vinyl aromatic monomer unit. When the sum of the content of the above-mentioned ethylene-α-olefin copolymer (B) and the content of the above-mentioned hydrogenated product (C) contained in the thermoplastic elastomer composition is defined as W0 and the gel content is defined as W1, the value of the ratio W1 / W0 is 0.01 to 0.70, wherein W0 and W1 are expressed in mass %.

2. The thermoplastic elastomer composition according to claim 1, wherein The hydrogenated product (C) is a styrene-based block copolymer.

3. The thermoplastic elastomer composition according to claim 1 or 2, wherein The content of the hydrogenated product (C) contained in the thermoplastic elastomer composition is 180 to 250 parts by mass based on 100 parts by mass of the olefin-based resin (A).

4. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein The first composition is prepared by melt-kneading the olefin resin (A), the ethylene-α-olefin copolymer (B) and the crosslinking agent (F). The thermoplastic elastomer composition is prepared by melt-kneading the first composition and the second composition.

5. A method for producing a thermoplastic elastomer composition, characterized in that: Having the following (i) or (ii), (i) a step of dynamically crosslinking an olefin resin (A) and an ethylene-α-olefin copolymer (B) using a crosslinking agent (F), adding a hydrogenated product (C) to the latter stage of the same extruder, melt-kneading the mixture, and then taking out a thermoplastic elastomer composition from the extruder, (ii) a step of dynamically crosslinking an olefin resin (A) and an ethylene-α-olefin copolymer (B) using a crosslinking agent (F), taking out the crosslinked product from an extruder after the crosslinking reaction is completed, and remelting and extruding the crosslinked product and the hydrogenated product (C) to obtain a thermoplastic elastomer composition, The content of the ethylene-α-olefin copolymer (B) contained in the thermoplastic elastomer composition is 10 to 180 parts by mass based on 100 parts by mass of the olefin-based resin (A). The content of the hydrogenated product (C) contained in the thermoplastic elastomer composition is 170 to 500 parts by mass based on 100 parts by mass of the olefin-based resin (A). When the sum of the content of the above-mentioned ethylene-α-olefin copolymer (B) and the content of the above-mentioned hydrogenated product (C) contained in the thermoplastic elastomer composition is defined as W0 and the gel content is defined as W1, the value of the ratio W1 / W0 is 0.01 to 0.70, wherein W0 and W1 are expressed in mass %. 6 . An instrument panel skin comprising the thermoplastic elastomer composition according to claim 1 .

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