Specification
Title of invention: Polymer composition and its use
Technical field
[0001]
　The present invention relates to polymer compositions and their uses.
Background technology
[0002]
　Thermoplastic elastomers are lightweight and easy to recycle, so they are used as energy-saving and resource-saving elastomers, especially as alternatives to vulcanized rubber and vinyl chloride resin for automobile parts, industrial machinery parts, electrical / electronic parts, building materials, etc. Widely used.
[0003]
　Among them, the olefin-based thermoplastic elastomer is made of ethylene / propylene / non-conjugated diene copolymer (EPDM) and crystalline polyolefin such as polypropylene as raw materials, and therefore has a lighter specific gravity and heat resistance than other thermoplastic elastomers. Has excellent durability such as aging resistance and weather resistance.
[0004]
　As a thermoplastic elastomer used for a skin member of an automobile interior part, excellent tactile feel and excellent oil resistance are required.
[0005]
　However, flexibility and oil resistance are contradictory physical properties, and a thermoplastic elastomer having both flexibility and oil resistance has not been reported.
[0006]
　A flexible composition has been reported as a thermoplastic elastomer composition in which an olefin-based thermoplastic elastomer and a styrene-based thermoplastic elastomer are blended (for example, Patent Documents 1 and 2).
[0007]
　Patent Document 1 describes a specific polypropylene resin and a specific propylene with respect to an olefin-based thermoplastic elastomer (I) obtained by dynamically heat-treating a mixture containing a specific polypropylene resin, an ethylene-based copolymer rubber, and a softening agent. A thermoplastic elastomer composition for injection foam molding comprising a thermoplastic elastomer (II) containing an α-olefin copolymer rubber and a softening agent, an ethylene/α-olefin copolymer, and a styrene thermoplastic elastomer. It is described that the product has fluidity, foamability and flexibility and can be suitably used for interior parts of automobiles (for example, abstract, paragraph 0064).
[0008]
　Patent Document 2 discloses a composition containing a specific olefin-based thermoplastic elastomer and a specific styrene-based thermoplastic elastomer, and a thermoplastic elastomer composition having a type A hardness (instantaneous value) of 55 or less in accordance with JIS K6253. It is described that it has both flexibility and moldability (injection foaming) and can be used for automobile parts such as automobile interior parts and automobile exterior parts (for example, claim 1, paragraph 0096).
[0009]
　Neither of Patent Documents 1 and 2 mention oil resistance.
Prior art documents
Patent literature
[0010]
Patent Document 1: Japanese Patent Laid-Open No. 2002-206034
Patent Document 2: International Publication No. 2016/039310
Summary of the invention
Problems to be Solved by the Invention
[0011]
　An object of the present invention is to provide a polymer composition capable of producing a skin member for an automobile interior part that has both flexibility and oil resistance.
Means for solving the problem
[0012]
　The gist of the present invention is as follows.
(1) 20 to 60 parts by mass of a component derived from ethylene copolymer rubber (A), 5 to 30 parts by mass of a component derived from polypropylene resin (B), and 4 to 14 parts by mass of a component derived from styrene-based thermoplastic elastomer (C). Parts and 5 to 70 parts by mass of the component derived from the softening agent (D) (the total amount of the components (A), (B), (C) and (D) is 100 parts by mass), and the styrene-based thermoplastic resin A composition in which the mass ratio ((C)/(D)) of the component derived from the elastomer (C) and the component derived from the softening agent (D) is 0.01 to 1.
(2) At least the component derived from the ethylene-based copolymer rubber (A) and the component derived from the styrene-based thermoplastic elastomer (C) are crosslinked by a cross-linking agent (E) containing an organic peroxide. The composition according to 1).
(3) 20 to 60 parts by mass of the component derived from the ethylene copolymer rubber (A), 5 to 14 parts by mass of the component derived from the polypropylene resin (B), and 5 to 12 parts by mass of the component derived from the styrene thermoplastic elastomer (C). (1) or 5 parts by mass to 70 parts by mass of the component derived from the softening agent (D) (the total amount of the components (A), (B), (C) and (D) is 100 parts by mass) or The composition according to (2).
(4) The styrene-based thermoplastic elastomer (C) is selected from block copolymers of styrene and one or more conjugated dienes selected from butadiene and isoprene, and hydrogenated products thereof (1) to (3). The composition according to any one of 1.
(5) The composition according to any one of (2) to (4) above, wherein the cross-linking agent (E) is composed of only an organic peroxide.
(6) The composition according to any one of (1) to (5) above, which has an MFR of 0.1 to 150 at 230° C. under a load of 10 kg.
(7) A skin member for an automobile interior part, comprising the composition according to any one of (1) to (6) above.
(8) An automobile interior part having the skin member according to (7) above.
(9) The automobile interior part according to (8), which is an instrument panel or a door trim.
Effect of the invention
[0013]
　　Since the composition of the present invention has both a soft touch feeling and excellent oil resistance, it is suitable for use as a skin member of an automobile interior part. Therefore, the skin member of the automobile interior part and the automobile interior part of the present invention have both a soft touch and excellent oil resistance. As used herein, both soft feel and softness indicate low hardness.
MODE FOR CARRYING OUT THE INVENTION
[0014]
　The composition of the present invention comprises at least a component derived from an ethylene copolymer rubber (A), a component derived from a polypropylene resin (B), a component derived from a styrene-based thermoplastic elastomer (C), and a component derived from a softening agent (D). Contains ingredients.
　In the present invention, “component derived from ethylene copolymer rubber”, “component derived from polypropylene resin”, “component derived from styrene-based thermoplastic elastomer” and “component derived from softening agent” are ethylene-based copolymers, respectively. It represents a component obtained from a raw material of a synthetic rubber, a polypropylene resin, a styrene-based thermoplastic elastomer and a softening agent.
[0015]
[Ethylene Copolymer Rubber (A)]
　The ethylene copolymer rubber (A) used in the present invention is an elastic copolymer rubber containing ethylene and an α-olefin having 3 to 20 carbon atoms as main components. And preferably, an amorphous random elastic copolymer rubber composed of ethylene and an α-olefin having 3 to 20 carbon atoms, and an amorphous random elastic rubber composed of ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated polyene. A copolymer rubber may be used.
[0016]
　Specific examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 2-methyl-1-propene, 3-methyl-1-pentene, Examples thereof include 4-methyl-1-pentene and 5-methyl-1-hexene. These α-olefins may be used alone or in combination of two or more.
[0017]
　The molar ratio of ethylene to the α-olefin having 3 to 20 carbon atoms in the ethylene-based copolymer rubber (A) is usually 55/45 to 85/15, preferably 60/40 to 83/17.
[0018]
　Specific examples of the non-conjugated polyene include dicyclopentadiene, cyclooctadiene, methylene norbornene (eg, 5-methylene-2-norbornene), ethylidene norbornene (eg, 5-ethylidene-2-norbornene), methyltetrahydro. Cyclic diene such as inden, 5-vinyl-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, norbornene; 1,4-hexadiene, 3-methyl-1 , 4-Hexadiene, 4-Methyl-1,4-Hexadien, 5-Methyl-1,4-Hexadene, 4,5-dimethyl-1,4-Hexadene, 6-Methyl-1,6-octadene, 7-Methyl -1,6-octadiene, 6-ethyl-1,6-octadiene, 6-propyl-1,6-octadiene, 6-butyl-1,6-octadiene, 6-methyl-1,6-nonadiene, 7-methyl -1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene, 6-methyl-1,6-decadiene, 7-methyl-1,6-decadiene, 6-methyl Chain dienes such as -1,6-undecadiene and 7-methyl-1,6-octadiene; trienes such as 2,3-diisopropylidene-5-norbornene and 2-ethylidene-3-isopropylidene-5-norbornene Can be mentioned. Among these non-conjugated polyenes, 5-ethylidene-2-norbornene, dicyclopentadiene, 1,4-hexadiene and the like are preferable, and 5-ethylidene-2-norbornene is more preferable.
[0019]
　As the ethylene copolymer rubber (A), ethylene/propylene/non-conjugated diene copolymer rubber and ethylene/1-butene/non-conjugated diene copolymer rubber are preferable, and ethylene/propylene/non-conjugated diene copolymer is preferable. Rubber, especially ethylene/propylene/5-ethylidene-2-norbornene copolymer rubber, is particularly preferable in that a thermoplastic elastomer having an appropriate crosslinked structure can be obtained.
[0020]
　The Mooney viscosity [ML 1 + 4 (125 ° C.)] of the ethylene-based copolymer rubber (A) is usually 35 to 300, preferably 40 to 160.
[0021]
　The ethylene-based copolymer rubber (A) used in the present invention may be a so-called oil-extended rubber in which a softening agent, preferably a mineral oil-based softening agent, is blended during its production. Examples of the mineral oil-based softener include conventionally known mineral oil-based softeners such as paraffin-based process oil.
[0022]
　The iodine value of the ethylene copolymer rubber (A) is usually 3 to 30, preferably 5 to 25. When the iodine value of the ethylene copolymer rubber (A) is in such a range, it is crosslinked in a well-balanced manner, and a thermoplastic elastomer composition having excellent moldability and rubber elasticity can be obtained.
[0023]
　The blending amount of the ethylene-based copolymer rubber (A) is 100 parts by mass of the total amount of the ethylene-based copolymer rubber (A), polypropylene resin (B), styrene-based thermoplastic elastomer (C) and softening agent (D). On the other hand, it is 20 to 60 parts by mass, preferably 30 to 50 parts by mass, more preferably 30 to 45 parts by mass. If it is within this range, it has excellent flexibility.
[0024]
[Polypropylene Resin (B)]
　The polypropylene resin (B) used in the present invention is a high molecular weight solid obtained by polymerizing propylene alone or propylene and one or more other monoolefins by a high pressure method or a low pressure method. Composed of products.
[0025]
　Suitable raw material olefins other than propylene in the polypropylene resin (B) are preferably α-olefins having 2 or 4 to 20 carbon atoms, specifically ethylene, 1-butene, 1-pentene, 1-hexene, 1 -Octen, 1-decene, 2-methyl-1-propene, 3-methyl-1-pentene, 4-methyl-1-pentene, 5-methyl-1-hexene and the like can be mentioned. The polymerization mode may be random type or block type as long as a resinous material is obtained. These polypropylene resins may be used alone or in combination of two or more kinds.
[0026]
　The polypropylene resin (B) used in the present invention is preferably a propylene-based polymer having a propylene content of 40 mol% or more, more preferably a propylene-based polymer having a propylene content of 50 mol% or more.
[0027]
　Among these polypropylene resins, propylene homopolymer, propylene/ethylene block copolymer, propylene/ethylene random copolymer, propylene/ethylene/butene random copolymer and the like are particularly preferable.
[0028]
　The melting point of the polypropylene resin (B) used in the present invention is usually 80 to 170°C, preferably 120 to 170°C.
[0029]
　The polypropylene resin (B) used in the present invention has an MFR (ASTM D1238-65T, 230 ° C., 2.16 kg load) usually in the range of 0.01 to 100 g / 10 minutes, particularly 0.05 to 50 g / 10 minutes. It is preferable.
[0030]
　The polypropylene resin (B) used in the present invention preferably has an isotactic structure as a three-dimensional structure, but a syndiotactic structure, a mixture of these structures, or a partly atactic structure is also used. be able to.
[0031]
　The polypropylene resin (B) used in the present invention is polymerized by various known polymerization methods.
　The blending amount of the polypropylene resin (B) is 100 parts by mass of the total amount of the ethylene copolymer rubber (A), the polypropylene resin (B), the styrene thermoplastic elastomer (C) and the softening agent (D). The amount is 1 to 40 parts by mass, preferably 5 to 30 parts by mass, more preferably 5 to 14 parts by mass. Within this range, the balance between flexibility and oil resistance is particularly excellent.
[0032]
[Styrene-based thermoplastic elastomer (C)]
　Specific examples of the styrene-based thermoplastic elastomer (C) used in the present invention include styrene/isoprene block copolymers and hydrogenated products of styrene/isoprene block copolymers ( SEP), hydrogenated product of styrene/isoprene/styrene block copolymer (SEPS; polystyrene/polyethylene/propylene/polystyrene block copolymer), styrene/butadiene copolymer, styrene/butadiene block copolymer, styrene/butadiene Examples thereof include hydrogenated block copolymers (SEBS; polystyrene/polyethylene/butylene/polystyrene block copolymers), and more specifically, Septon [manufactured by Kuraray Co., Ltd.] and EARNESTON [Kuraray Plastics Co., Ltd.]. Made], HYBRAR [made by Kuraray Co., Ltd.], Kraton, KRATON, Kraton Polymer [made by Kraton Polymer], Europrene SOLT [made by Veralis], JSR-TR, JSR-SIS [made by JSR] ], Quintac [manufactured by Nippon Zeon Co., Ltd.], Tuftec [manufactured by Asahi Kasei Kogyo Co., Ltd.] (above product name) and the like.
[0033]
　Among these, the styrene-based thermoplastic elastomer (C) is one or more selected from a block copolymer of styrene and one or more conjugated dienes selected from butadiene and isoprene and a hydrogenated product thereof. This is more preferable in terms of oil resistance of the composition. Particularly preferably, the component (C) is a styrene / isoprene block copolymer, a styrene / isoprene block copolymer hydrogenated product, a styrene / isoprene / styrene block copolymer hydrogenated product, a styrene / butadiene block copolymer, and the like. It is one or more selected from hydrogenated products of styrene/butadiene block copolymers.
[0034]
　The styrene-based thermoplastic elastomer (C) used in the present invention has a type A hardness (instantaneous value) according to JIS K6253 of usually 30 to 96, preferably 35 to 69.
[0035]
　The styrene-based thermoplastic elastomer (C) used in the present invention has a styrene content of usually 10 to 70% by mass, preferably 20 to 50% by mass.
[0036]
　The blending amount of the styrene-based thermoplastic elastomer (C) is 100 parts by mass of the total amount of the ethylene-based copolymer rubber (A), polypropylene resin (B), styrene-based thermoplastic elastomer (C) and softener (D). On the other hand, the amount is 4 to 14 parts by mass, preferably 5 to 12 parts by mass, more preferably 5 to 11 parts by mass, particularly preferably 5 to 10 parts by mass. When the compounding amount of the styrene-based thermoplastic elastomer (C) is 4 to 14 parts by mass, the oil resistance, the weight change rate and the flexibility are good, and the heat resistance does not decrease, so that the moldability in vacuum molding or the like is good. (In particular, the residual transfer property of the texture) is also good. When the upper limit of the blending amount of the styrene-based thermoplastic elastomer (C) is 10 parts by mass or less, the heat resistance does not decrease in addition to the oil resistance, the vacuum formability (texture transfer residual property), and the separation from the roll. Also excellent in formability.
[0037]
　The styrene-based thermoplastic elastomer (C) may be a so-called oil-extended product containing a softening agent, preferably a mineral oil-based softening agent. Examples of the mineral oil-based softener include conventionally known mineral oil-based softeners such as paraffin-based process oil.
[0038]
[Softening agent (D)] The
　softening agent is an ethylene copolymer rubber (A), a polypropylene resin (B), a styrene thermoplastic elastomer (C), or an ethylene copolymer rubber (A) and a polypropylene resin in advance. It is added by the method of pouring at the time of mixing (B) or at the time of dynamically crosslinking the mixture. In that case, you may add the said method individually or in combination of the said method.
[0039]
　Specific examples of the softening agent used in the present invention include petroleum-based softening agents such as process oil, lubricating oil, paraffin, liquid paraffin, polyethylene wax, polypropylene wax, petroleum asphalt, and petrolatum; coal tar, coal tar pitch, and the like. Hydrocarbon softeners; fatty oil softeners such as sunflower oil, flaxseed oil, rapeseed oil, soybean oil, palm oil; tall oil; sub, (factis); waxes such as beeswax, carnauba wax, lanolin; stearic acid , Fatty acids and fatty acid salts such as palmitic acid, stearic acid, barium stearate, calcium stearate, zinc laurate; naphthenic acid; pine oil, rosin or its derivatives; terpene resin, petroleum resin, coumarone indene resin, atactic polypropylene, etc. Synthetic polymer substances; ester-based softeners such as dioctyl phthalate, dioctyl adipate, dioctyl sebacate; microcrystallin wax, liquid polybutadiene, modified liquid polybutadiene, liquid polyisoprene, terminal modified polyisoprene, hydrogenated terminal modified polyisoprene, liquid Examples thereof include thiocol and hydrocarbon synthetic lubricating oil. Among them, petroleum-based softeners, particularly process oils are preferably used.
[0040]
　The blending amount of the softening agent (D) is 100 parts by mass of the total amount of the ethylene copolymer rubber (A), the polypropylene resin (B), the styrene thermoplastic elastomer (C) and the softening agent (D). The amount is 5 to 70 parts by mass, preferably 30 to 55 parts by mass, and more preferably 41 to 55 parts by mass. When the blending amount of the softening agent (D) is less than 5 parts by mass, the oil resistance and the weight change rate are deteriorated, while when the blending amount of the softening agent (D) exceeds 70 parts by mass, the heat resistance is high. As a result, the moldability in vacuum molding and the like (particularly the residual texture of grain transfer) deteriorates.
[0041]
　In the composition of the present invention, the mass ratio ((C)/(D)) of the styrene-based thermoplastic elastomer (C) and the softening agent (D) is 0.01 from the viewpoint of oil resistance, heat resistance and roll processability. To 1, preferably 0.02 to 0.9, more preferably 0.03 to 0.7, more preferably 0.05 to 0.5, particularly preferably 0.07 to 0.3, most preferably 0. .1 to 0.3.
[0042]
[Crosslinking Agent]
　Examples of the crosslinking agent used in the present invention include organic peroxides, sulfur, sulfur compounds, phenolic vulcanizers such as phenolic resins, etc. Among them, organic peroxides are the color of the molded product and the resin. Excellent mechanical strength such as elongation at break in a tensile test, resin easily stretches during secondary processing of a molded product, and excellent moldability (for moldability, it is also related to excellent elongation at break in a tensile test to some extent. It is preferably used from the viewpoint of vacuum formability, particularly corner transferability, and the cross-linking agent (E) includes the hue point, mechanical strength, and moldability of the molded product (particularly vacuum formability such as corner transferability). In this respect, it is more preferable to use only the organic peroxide. Even when only organic peroxide is used as the cross-linking agent, a cross-linking aid or a polyfunctional vinyl monomer described later may be used.
[0043]
　Specific examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, and 2,5-dimethyl-2. 5-di-(tert-butylperoxy)hexyne-3,1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, n -Butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, tert-butylperoxyisopropyl carbonate, diacetylperoxide, lauroyl Examples thereof include peroxides and tert-butyl cumyl peroxide.
[0044]
　Of these, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane and 2,5-dimethyl-2,5-di-(tert-butyl) are preferred in terms of odor and scorch stability. Peroxy) Hexin-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (Tert-butylperoxy)valerate is preferable, and 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane and 1,3-bis(tert-butylperoxyisopropyl)benzene are most preferable.
[0045]
　The organic peroxide is usually 0.01 to 5 with respect to 100 parts by mass of the total amount of the ethylene copolymer rubber (A), the polypropylene resin (B), the styrene thermoplastic elastomer (C) and the softening agent (D). It is used in a proportion of parts by mass, preferably 0.05 to 3 parts by mass, more preferably 0.05 to 1 part by mass. From the viewpoint of flexibility and oil resistance, it is preferable to use 0.01 to 2 parts by mass of the organic peroxide with respect to 100 parts by mass of the ethylene copolymer rubber (A) used as a raw material. The value of is preferably 1.9 parts by mass, more preferably 1.6 parts by mass, further preferably 1.5 parts by mass, particularly preferably 1.4 parts by mass, and the lower limit value of the addition amount is preferable. Is 0.02 parts by mass, more preferably 0.05 parts by mass.
[0046]
　In the crosslinking treatment with the organic peroxide, sulfur, p-quinonedioxime, p,p′-dibenzoylquinonedioxime, N-methyl-N,4-dinitrosoaniline, nitrosobenzene, diphenylguanidine, trimethylolpropane, N , N'-m-phenylenedi maleimide, divinylbenzene, triallyl cyanurate, triallyl isocyanurate and other cross-linking aids, or ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, A polyfunctional methacrylate monomer such as allyl methacrylate and a polyfunctional vinyl monomer such as vinyl butyrate and vinyl stearate can be blended.
[0047]
　By using the above compounds, a uniform and mild crosslinking reaction can be expected. In particular, in the present invention, divinylbenzene is most preferable. Divinylbenzene is easy to handle, has good compatibility with the ethylene copolymer rubber (A) and the polypropylene resin (B), which are the main components of the above-mentioned substance to be crosslinked, and solubilizes the organic peroxide. Since it has a function and acts as a dispersant for the organic peroxide, a resin composition having a uniform cross-linking effect by heat treatment and a good balance of fluidity and physical properties can be obtained.
[0048]
　The cross-linking aid is usually 0.01 with respect to 100 parts by mass of the total amount of the ethylene copolymer rubber (A), the polypropylene resin (B), the styrene thermoplastic elastomer (C) and the softening agent (D). It is used in a proportion of ˜15 parts by mass, preferably 0.03 to 12 parts by mass.
[0049]
[Other additives]
　The composition of the present invention comprises a component derived from an ethylene copolymer rubber (A), a component derived from a polypropylene resin (B), a component derived from a styrene-based thermoplastic elastomer (C) and a softening agent (D). ) Derived components may be present in the above-mentioned amounts, but other polymers such as butyl rubber, polyisobutylene rubber, nitrile rubber (NBR), and natural rubber (NR) may be present as long as the object of the present invention is not impaired. , And silicone rubber may be added.
　When another polymer is used, the addition amount is usually 0.1 to 50 parts by mass, preferably 5 to 40 parts by mass with respect to 100 parts by mass of the component (A).
　In the composition of the present invention, if necessary, additives such as a slip agent, a nucleating agent, a filler, an antioxidant, a weathering stabilizer, and a colorant may be added within a range that does not impair the object of the present invention. Can be done. The total amount of these other additives is usually 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 100 parts by mass, based on 100 parts by mass of the total amount of the components (A) to (D). Is 0.1 to 5 parts by mass. The filler is usually 1 to 50 parts by mass, preferably 1 to 45 parts by mass, and more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the component (A).
[0050]
　Examples of the nucleating agent include non-melting type and melting type crystallization nucleating agents, and these can be used alone or in combination of two or more kinds. Non-melting crystallization nucleating agents include inorganic substances such as talc, mica, silica and aluminum, brominated biphenyl ether, aluminum hydroxydi-p-tert-butylbenzoate (TBBA), organic phosphate and rosin-based crystallization. Examples include nucleating agents, substituted triethylene glycol terephthalates and Terylene & Nylon fibers, in particular aluminum hydroxy-di-p-tert-butyl benzoate, sodium methylenebis (2,4-di-tert-butylphenyl) phosphate, 2, 2'-Methylenebis (4,6-di-tert-butylphenyl) sodium phosphate, rosin-based crystallization nucleating agent is desirable. Examples of the melting crystallization nucleating agent include sorbitol compounds such as dibenzylidene sorbitol (DBS), substituted DBS, and lower alkyldibenzylidene sorbitol (PDTS).
[0051]
　Examples of the slip agent include fatty acid amide, silicone oil, glycerin, wax and paraffin oil.
[0052]
　As the filler, a conventionally known filler, specifically, carbon black, calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, alumina, barium sulfate, aluminum sulfate. , Calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite, glass fiber, glass spheres, shirasu balloon, basic magnesium sulfate whiskers, calcium titanate whiskers, aluminum borate whiskers, and the like.
[0053]
[Production Method of Composition of the Present Invention]
　The composition of the present invention is preferably an ethylene copolymer rubber (A), a polypropylene resin (B), a styrene thermoplastic elastomer (C) and a softening agent (D). It can be obtained by dynamically cross-linking a mixture containing a predetermined amount of optional components as necessary. When performing dynamic crosslinking, it is preferable to perform the heat treatment dynamically in the presence of the crosslinking agent, or in the presence of the crosslinking agent and the crosslinking aid. When the component (C) is also crosslinked as in the preferred embodiment, the oil resistance is excellent.
　Further, it is preferable that all of the raw materials (A) and (C) are dynamically heat-treated in the presence of a crosslinking agent or in the presence of the crosslinking agent and the crosslinking aid. .. It is preferable that at least a part of the component (B) and the component (D) are dynamically heat-treated in the presence of a cross-linking agent or in the presence of the cross-linking agent and the cross-linking aid, and the total amount of each is It is further preferred that is dynamically heat treated in the presence of a cross-linking agent.
　The crosslinking is preferably carried out by dynamically heat-treating 100 parts by mass of the ethylene copolymer rubber (A) in the presence of 0.01 to 2 parts by mass of an organic peroxide.
　Here, "dynamically heat-treating" means kneading in a molten state.
[0054]
　The dynamic heat treatment in the present invention is preferably performed in a non-open type apparatus, and is preferably performed in an atmosphere of an inert gas such as nitrogen or carbon dioxide gas. The temperature of the heat treatment is in the range of 300 ° C. from the melting point of the polypropylene resin (B), and is usually 150 to 270 ° C., preferably 170 ° C. to 250 ° C. The kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes. Further, the shear force applied is shear rate at 10 ~ 50,000Sec -1 , preferably 100 ~ 10,000Sec -1 in the range of.
[0055]
　The composition of the present invention is particularly suitable for solid molding, and normally does not use a foaming agent or the like.
[0056]
　As a kneading device, a mixing roll, an intensive mixer (for example, Banbury mixer, kneader), a single-screw or twin-screw extruder and the like can be used, but a non-open type device is preferable.
[0057]
　According to the present invention, a resin composition in which at least a part of the ethylene copolymer rubber (A) is crosslinked is obtained by the above-mentioned dynamic heat treatment.
[0058]
[Composition of the
　present invention ] The melt flow rate (MFR) measured at 230 ° C. under a load of 10 kgf or 2.16 kgf according to JIS K7210 of the composition of the present invention is not particularly limited, but is used in vacuum forming. From the viewpoint of achieving both corner transferability and texture transfer residue, the MFR measured at 230 ° C. under a load of 10 kgf is preferably 0.1 to 150 g / 10 min, and more preferably 0.1 to 80 g / 10 min.
　The composition of the present invention has a Shore A hardness (instantaneous value) of usually 30 to 60, preferably 40 to 54, measured according to JIS K6253.
[0059]
　The composition of the present invention is formed into a thermoplastic elastomer molded body by various known molding methods, specifically, various molding methods such as injection molding, extrusion molding, press molding, calender molding, and hollow molding. be able to. Further, a molded body such as a sheet obtained by the above molding method can be secondarily processed by thermoforming or the like. The composition of the present invention is excellent in sharpness of the shape of the corner portion when the sheet is vacuum formed into a shape having the corner portion at the time of thermoforming. Examples of the shape having the corner portion include a shape of a skin member of an automobile instrument panel or a skin member of an automobile door trim. In addition, even when the sheet is subjected to thermoforming after being textured, the easiness of leaving the texture after thermoforming is excellent. The reason why the composition of the present invention is excellent in the transferability of the corner portion and the residual transfer of the textured surface is that the composition of the present invention has heat resistance. In the present invention, excellent one or both of the transferability of the corner portion and the texture transfer residual property may be said to be excellent in vacuum formability.
[0060]
　The above composition has both a soft touch and excellent oil resistance, and is most suitable as a skin member for automobile interior parts, for example, a skin member for automobile instrument panels and a skin member for automobile door trims.
[0061]
　This specification includes the content described in the specification and drawing of Japanese Patent Application No. 2017-237039 which are the basis of the priority of this application.
Example
[0062]
　Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. The methods of measuring physical properties and the methods of evaluation performed in Examples and Comparative Examples are as follows.
[0063]
[Shore A Hardness] According to
　JIS K6253 (hardness test method), a Shore A hardness (instantaneous value) was obtained using a durometer using a press sheet having a thickness of 2 mm.
[0064]
[Melting point (Tm) of polypropylene resin (B)] The
　measurement was carried out by the following method using a differential scanning calorimetry (DSC ) in accordance with JIS K7121.
　About 5 mg of the polymer was sealed in a measuring aluminum pan of a differential scanning calorimeter (DSC220C type) manufactured by Seiko Instruments Inc., and heated from room temperature to 200 ° C. at 10 ° C./min. The polymer was held at 200°C for 5 minutes to completely melt it, then cooled at 10°C/min to -50°C. After being left at −50° C. for 5 minutes, the second heating was performed at 10° C./minute to 200° C., and the peak temperature (° C.) in this second heating was taken as the melting point (Tm) of the polymer. When a plurality of peaks are detected, the peak detected on the highest temperature side was adopted.
[0065]
[Tensile Properties]
　Measured according to the method of JIS K6251.
　The test piece was used by punching out a No. 3 dumbbell piece from a press sheet having a thickness of 2 mm. Measurement temperature: 23 ° C.
　M 100 : 100% elongation at a stress
　(MPa) T B : tensile strength
　(MPa) E B : elongation at break (%)
[0066]
[Oil resistance test: rate of weight change]
　Liquid paraffin (soft) (code number: 26132-35 manufactured by Nacalai Tesque, Inc.) was used as a test oil, and a 2 mm press sheet was immersed at 80°C for 24 hours. Then, the sample surface was wiped off, and the weight change rate was measured at n=3.
(Criteria for Oil Resistance)
◎: Weight change rate is 110 or less
◯: Weight change rate is more than 110 and 130 or less
Δ: Weight change rate is more than 130 and 150 or less
×: Weight change rate is more than 150
[0067]
[Flexibility]
　The hardness of the thermoplastic elastomer can be represented by Shore A hardness. If the value of Shore A hardness is high, the material is hard, and if it is low, the material is soft and flexible. The criteria for flexibility in this case are shown below.
(Criteria for Flexibility)
A: Shore A hardness is 45 or less
O: Shore A hardness is 46 to 54
B: Shore A hardness is 55 to 59
X: Shore A hardness is 60 or more
[0068]
[Melt Flow Rate: MFR] The
　melt flow rate was measured at 230° C. under a load of 10 kgf or 2.16 kgf according to JIS K7210.
[0069]
[Vacuum moldability] Molded into
　an instrument panel shape (molding temperature: 125°C), and using a vacuum molding machine BVF-1010-PWB manufactured by Fuse Vacuum Co., Ltd. It evaluated according to the standard.
(Evaluation criteria for corner transferability)
◎: The corners of the molded product are extremely sharp
○: The corners of the molded product are sharp
△: The corners of the molded product are slightly rounded
×: The molded product The corners are rounded
(evaluation criteria for residual texture transfer)
◎: The transferred texture of the
molded product remains very clearly ○: The transferred texture of the molded product remains clearly
△: There is a part where the transferred grain of the molded body is thin
x: There is a part where the transferred grain of the molded body is about to disappear
[0070]
[Roll processability]
　The releasability from the roll was evaluated according to the following test conditions and criteria.
(Test conditions)
Equipment name: Yasuda Seiki Seisakusho No. 191-TM / WM test mixing roll
roll temperature: 180 ° C.
Rotation speed: 5 inches Front 12.2 / rear 15.3rpm
Sample weight: 100g
kneading time 10 min
thickness: 0.5 mmt
guide Width: 21cm
(releasing Judgment criteria of sex)
◎:
It is easily peeled from the roll by its own weight ◯: It is easily peeled by adding a hand
△: It is peeled though it is sticky
×: It sticks strongly to the roll and it does not peel / it does not peel easily
[0071]
[Examples 1 to 4 and Comparative Examples 1 to 7]

(1) The following ethylene-based copolymer rubber (A) was used.
Ethylene/propylene/diene copolymer rubber (EPDM) (trade name: 3072 EPM; manufactured by Mitsui Chemicals, Inc., ethylene content=64 mass %, diene content=5.4 mass %, Mooney viscosity ML(1+4) 125° C.= 51, oil extension=40 (PHR)
(2) The following was used as the polypropylene resin (B).
(A) Propylene/ethylene random copolymer (crystalline resin) (trade name: Prime Polypro B241, manufactured by Prime Polymer Co., Ltd., density: 0.91 g/cm 3 , MFR (temperature: 230° C., load: 2) .16 kg load): 0.5 g/10 minutes, melting point 140° C. measured by DSC, density 0.91 g/cm 3 )
(b) Propylene/ethylene block copolymer (trade name: EL-Pro P740J; SCG Chemicals) Manufactured by MFR (ASTM D1238-65T; 230° C., 2.16 kg load) 27 g/10 minutes, melting point 163° C. measured by DSC)
(3) The following butyl rubbers were used.
Butyl rubber (trade name: IIR065; manufactured by Exxon Mobil Chemical Co., unsaturated degree: 0.8 mol %, Mooney viscosity ML (1+8) 125° C.: 32) and propylene/ethylene block copolymer (trade name: EL-Pro P740J) Manufactured by SCG Chemicals, MFR (ASTM D1238-65T; 230° C., 2.16 kg load) 27 g/10 minutes, melting point 163° C.) 1:1 master batch product
(4) The propylene/ethylene copolymer is as follows: I used the one.
Made by The Dow Chemical Company, VERSIFY ™ 2400.05 (melt flow rate (230° C., 2.16 kg load) 2 g/10 minutes, density 863 kg/m 3 ), weight average molecular weight of 1.0×10 5 or more components Content 1.0%, content 2.5% of components having a weight average molecular weight of 5.0×10 4 or less, melting point 51.8° C.
(5) Use the following as the styrene-based thermoplastic elastomer (C) did.
Asahi Kasei Corporation Tuftec ™H1272: having a structure of polystyrene-hydrogenated polybutadiene-polystyrene, bound styrene content of 35% by mass, number average molecular weight of about 120,000 (paraffin oil (Idemitsu Kosan Diana Process Oil PW-380 [paraffin process oil, Kinematic viscosity: 381.6 cst (40° C.), 30.1 (100° C.), average molecular weight 746, ring analysis value: CA=0%, CN=27%, CP=73%]) 35% by mass oil-extended product (oil Extension amount = 56 (PHR)))
[0072]
(Example 1)
　Ethylene/propylene/diene copolymer rubber (EPDM) (trade name: 3072 EPM: manufactured by Mitsui Chemicals, Inc., ethylene content=64 mass %, diene content=5.4 mass %, Mooney viscosity ML( 1+4) 125° C.=51, oil extension=40(PHR)) 50 parts by mass, propylene/ethylene random copolymer (crystalline resin) (trade name: Prime Polypro B241, manufactured by Prime Polymer Co., Ltd., density: 0.91 g/cm 3 , MFR (temperature: 230° C., load: 2.16 kg load): 0.5 g/10 minutes, density 0.91 g/cm 3 ) 10 parts by mass, styrene-based thermoplastic elastomer (manufactured by Asahi Kasei Kogyo) Tuftec TM H1272, paraffin oil 35% by weight oil extended product (oil extension amount = 56 (PHR)) 10 parts by weight, the softening agent (trade name: available from Idemitsu Kosan Co., Diana process PW-100, paraffin oil) 30 parts by weight, the crosslinking agent After sufficiently mixing 0.40 parts by mass of organic peroxide (Perhexa 25B, manufactured by Nippon Oil & Fats Co., Ltd.) and 0.40 parts by mass of divinylbenzene as a cross-linking aid with a Henschel mixer, an extruder (part number KTX-30, Made by Kobe Steel Co., Ltd., Cylinder temperature: C1: 50 ° C, C2: 90 ° C, C3: 100 ° C, C4: 120 ° C, C5: 180 ° C, C6: 200 ° C, C7 to C14: 200 ° C, Die temperature: The obtained mixture was dynamically crosslinked at 200 ° C., screw rotation speed: 400 rpm, extrusion amount: 50 kg / h) to obtain pellets of the resin composition. The formulation and results are shown in Table 1.
[0073]
(Examples 2 and 3)
　Pellets of the resin composition were obtained in the same manner as in Example 1 except that the compounding amounts of the components were changed as shown in Table 1. The results are shown in Table 1.
[0074]
(Example 4)
　Pellets of the resin composition were obtained in the same manner as in Example 1 except that the compounding amounts of the components were changed as shown in Table 1 and the styrene-based thermoplastic elastomer was added after the crosslinking treatment. .
　That is, ethylene/propylene/diene copolymer rubber (EPDM) (trade name: 3072EPM: manufactured by Mitsui Chemicals, Inc., ethylene content=64 mass %, diene content=5.4 mass %, Mooney viscosity ML(1+4)125. C.=51, oil extension=40 (PHR) 36 parts by mass, propylene/ethylene random copolymer (crystalline resin) (trade name: Prime Polypro B241, manufactured by Prime Polymer Co., Ltd., density: 0.91 g) /Cm 3 , MFR (temperature: 230° C., load: 2.16 kg load): 0.5 g/10 minutes, density 0.91 g/cm 3 ) 10 parts by mass, softening agent (trade name: Diana Process PW manufactured by Idemitsu Kosan) -100, paraffin oil) 46 parts by mass, organic peroxide (Perhexa 25B, manufactured by Nippon Oil & Fats Co., Ltd.) 0.40 parts by mass as a cross-linking agent, and divinylbenzene 0.40 parts by mass as a cross-linking aid with a Henschel mixer. After mixing, extruder (product number KTX-30, manufactured by Kobe Steel, Ltd., cylinder temperature: C1:50°C, C2:90°C, C3:100°C, C4:120°C, C5:180°C, C6:200. C, C7-C14: 200° C., die temperature: 200° C., screw rotation speed: 400 rpm, extrusion rate: 50 kg/h), the resulting mixture was dynamically crosslinked to obtain pellets, and then the pellets. And styrene thermoplastic elastomer (Tuftec ™ manufactured by Asahi Kasei Corporation H1272 and a paraffinic oil 35% by mass oil-extended product (oil-extended amount=56 (PHR)) were mixed in the same extruder so that the blending amount of the components was the value shown in Table 1, and pellets of the resin composition were mixed. Got The results are shown in Table 1.
[0075]
(Comparative Example 1)
　Ethylene-propylene-diene copolymer rubber (EPDM) (trade name: 3072EPM: manufactured by Mitsui Chemicals, Inc., ethylene content = 64% by mass, diene content = 5.4% by mass, Mooney viscosity ML ( 1+4) 125° C.=51, oil extension=40 (PHR) 60 parts by mass, butyl rubber (trade name: IIR065; manufactured by ExxonMobil Chemical Co., unsaturated degree: 0.8 mol %, Mooney viscosity ML(1+8)125 C.: 32) and propylene/ethylene block copolymer (trade name: EL-Pro P740J; manufactured by SCG Chemicals, MFR (ASTM D1238-65T; 230° C., 2.16 kg load) 27 g/10 min, melting point 163° C.) 29 parts by weight of a 1:1 masterbatch product, 11 parts by weight of a softening agent (trade name: Diana Process PW-100 manufactured by Idemitsu Kosan, paraffin oil), an organic peroxide as a cross-linking agent (Perhexa 25B, manufactured by NOF Corporation) After thoroughly mixing 0.3 parts by mass and 0.2 parts by mass of divinylbenzene as a crosslinking aid with a Henschel mixer, an extruder (product number KTX-30, manufactured by Kobe Steel, Ltd., cylinder temperature: C1:50° C.) , C2: 90° C., C3: 100° C., C4: 120° C., C5: 180° C., C6: 200° C., C7 to C14: 200° C., die temperature: 200° C., screw rotation speed: 400 rpm, extrusion rate: 50 kg/ In h), the obtained mixture was dynamically crosslinked to obtain pellets of the resin composition. The formulations and results are shown in Table 2.
[0076]
(Comparative Example 2)
　Ethylene/propylene/diene copolymer rubber (EPDM) (trade name: 3072 EPM: manufactured by Mitsui Chemicals, Inc., ethylene content=64 mass %, diene content=5.4 mass %, Mooney viscosity ML( 1+4) 125° C.=51, oil extension=40(PHR)) 55 parts by mass, propylene/ethylene block copolymer (trade name: EL-Pro P740J; manufactured by SCG Chemicals, melt flow rate (ASTM D1238-65T; 230 ° C., 2.16 kg load) 27 g / 10 min, melting point 163 ° C.) 16 parts by mass, propylene / ethylene copolymer (trade name: VERSIFY TM 2400.05, manufactured by The Dow Chemical Company, melt flow rate (230 ° C.) , 2.16 kg load) 2 g/10 minutes, density 863 kg/m 3 ) 8 parts by mass, softening agent (trade name: Diana Process PW-100 manufactured by Idemitsu Kosan, paraffin oil) 21 parts by mass, organic peroxide (perhexa) as a cross-linking agent. After thoroughly mixing 25B, 0.25 parts by mass of Nippon Oil & Fats Co., Ltd., and 0.15 parts by mass of divinylbenzene as a cross-linking aid with a Henschel mixer, an extruder (part number KTX-30, Kobe Steel Co., Ltd.) Manufacturing, Cylinder temperature: C1:50°C, C2:90°C, C3:100°C, C4:120°C, C5:180°C, C6:200°C, C7-C14:200°C, Die temperature: 200°C, screw rotation The obtained mixture was dynamically crosslinked at a number of 400 rpm and an extrusion rate of 50 kg/h) to obtain pellets of the resin composition. The formulations and results are shown in Table 2.
[0077]
(Comparative Example 3)
　Ethylene-propylene-diene copolymer rubber (EPDM) (trade name: 3072EPM: manufactured by Mitsui Chemicals, Inc., ethylene content = 64% by mass, diene content = 5.4% by mass, Mooney viscosity ML ( 1+4) 125° C.=51, oil extension=40 (PHR)) 28 parts by mass, propylene/ethylene random copolymer (crystalline resin) (trade name: Prime Polypro B241, manufactured by Prime Polymer Co., Ltd., density: 0.91 g/cm 3 , MFR (temperature: 230° C., load: 2.16 kg load): 0.5 g/10 minutes, density 0.91 g/cm 3 ) 13 parts by mass, styrene-based thermoplastic elastomer (manufactured by Asahi Kasei Kogyo) Tuftec ™ H1272, paraffinic oil 35 mass% oil extended product (oil extended amount = 56 (PHR)) 25 parts by mass, softening agent (trade name: Diana Process PW-100 manufactured by Idemitsu Kosan, paraffin oil) 34 parts by mass, crosslinking agent As an organic peroxide (Perhexa 25B, manufactured by NOF CORPORATION) 0.40 parts by mass, and divinylbenzene 0.40 parts by mass as a cross-linking aid, were thoroughly mixed with a Henschel mixer, and then an extruder (product number KTX-30, Kobe Steel, Cylinder temperature: C1:50°C, C2:90°C, C3:100°C, C4:120°C, C5:180°C, C6:200°C, C7-C14:200°C, Die temperature: The resulting mixture was dynamically crosslinked at 200° C., screw rotation speed: 400 rpm, extrusion rate: 50 kg/h) to obtain resin composition pellets, which are shown in Table 2.
[0078]
(Comparative Examples 4 to 7)
　Pellets of the resin composition were obtained in the same manner as in Comparative Example 1 except that the components and the blending amounts thereof were changed as shown in Table 2. The results are shown in Table 2.
[0079]
[table 1]

[0080]
[Table 2]

[0081]
　From the results shown in Tables 1 and 2, it can be seen that the compositions of Examples 1 to 3 have both soft touch and excellent oil resistance. The hue of the pellets is generally good if it is milky white, and coloring such as yellow is not preferable, but the hue of the pellets of all the compositions of Examples 1 to 3 was milky white. ..
　Since Comparative Examples 1 and 2 do not contain the styrene thermoplastic elastomer (C), the weight change rate (oil resistance) is poor. Comparative Example 3 shows that when the blending amount of the styrene-based thermoplastic elastomer (C) is too large, the oil resistance deteriorates, and the embossed transfer residual property and the releasability from the roll deteriorate. Comparative Example 4 shows that when the blending amount of the styrene-based thermoplastic elastomer (C) is too small, the oil resistance and the vacuum moldability are deteriorated. Comparative Example 5 shows that in the case of a hard material in which the polypropylene resin (B) is blended in a large amount, the oil resistance is somewhat good without blending the styrene-based thermoplastic elastomer (C), but the flexibility is poor. Comparative Example 6 shows that when a styrene-based thermoplastic elastomer (C) is blended with a hard material containing a large amount of the polypropylene resin (B), the oil resistance is improved but the flexibility is poor. Comparative Example 7 shows that when the blending amount of the styrene-based thermoplastic elastomer (C) is larger than that of the softening agent, the oil resistance deteriorates.
[0082]
　All publications, patents and patent applications cited in this specification are incorporated herein by reference as they are.
The scope of the claims
[Claim 1]
　20 to 60 parts by mass of the component derived from the ethylene copolymer rubber (A), 5 to 30 parts by mass of the component derived from the polypropylene resin (B), 4 to 14 parts by mass of the component derived from the styrene thermoplastic elastomer (C) and softening. 5 to 70 parts by mass of the component derived from the agent (D) (the total amount of the components (A), (B), (C) and (D) is 100 parts by mass), and the styrene-based thermoplastic elastomer (C ) And the softener (D)-derived component have a mass ratio ((C)/(D)) of 0.01 to 1.
[Claim 2]
　The component derived from at least the ethylene copolymer rubber (A) and the component derived from the styrene thermoplastic elastomer (C) are crosslinked with a crosslinking agent (E) containing an organic peroxide. Composition.
[Claim 3]
　20 to 60 parts by mass of the component derived from the ethylene copolymer rubber (A), 5 to 14 parts by mass of the component derived from the polypropylene resin (B), 5 to 12 parts by mass of the component derived from the styrene thermoplastic elastomer (C) and softening. The composition according to claim 1 or 2, containing 5 to 70 parts by mass of a component derived from the agent (D) (the total amount of the components (A), (B), (C) and (D) is 100 parts by mass). Stuff.
[Claim 4]
　The styrene-based thermoplastic elastomer (C) is selected from block copolymers of styrene and one or more conjugated dienes selected from butadiene and isoprene, and hydrogenated products thereof, according to any one of claims 1 to 3. The composition as described.
[Claim 5]
　The composition according to any one of claims 2 to 4, wherein the cross-linking agent (E) consists only of organic peroxide.
[Claim 6]
　The composition according to any one of claims 1 to 5, which has an MFR of 0.1 to 150 at 230°C under a load of 10 kg.
[Claim 7]
　A skin member for an automobile interior part, comprising the composition according to any one of claims 1 to 6.
[Claim 8]
　An automobile interior component having the skin member according to claim 7.
[Claim 9]
　The automobile interior part according to claim 8, which is an instrument panel or a door trim.