Thermoplastic elastomer composition and molded article formed therefrom

Abstract

The purpose of the present invention is to provide: a thermoplastic elastomer which has excellent fogging resistance (low fogging properties) and flexibility, and which is capable of further reducing the environmental burden when a biomass-derived softening agent is used; and a molded article. A thermoplastic elastomer composition containing (A) 100 parts by mass of an ethylene-alpha-olefin-non-conjugated polyene copolymer, (B) 10-200 parts by mass of a polypropylene resin, and (C) 10-200 parts by mass of a softening agent, at least a portion of the thermoplastic elastomer composition being crosslinked, the softening agent has a paraffin-based carbon atom content (% CP) of from 80% to 100% (inclusive) as determined by gel permeation chromatography (GPC) as determined in accordance with ASTM D3238-85 or ASTM D2140.

Description

Technical Field

[0001] The present invention relates to a thermoplastic elastomer composition and a molded article formed therefrom. Background Art

[0002] Due to the increasing environmental awareness and the expected reduction in the reserves of fossil resources such as natural gas, the importance of bioplastics containing materials obtained from biomass-derived raw materials is increasing day by day.

[0003] Among plastic materials, olefin-based thermoplastic elastomers are an industrially important polymer group and are used in various applications, such as the automotive field, consumer products, packaging, pharmaceuticals, and the construction field. Therefore, even for materials containing thermoplastic elastomers, a reduction in the environmental load is required.

[0004] It is known that in order to increase flexibility and rubber elasticity, a softening agent such as a mineral oil softening agent is blended in the thermoplastic elastomer. In this regard, as a softening agent or plasticizer blended in a composition containing a thermoplastic elastomer, a substance obtained from a biomass-derived raw material has also been tried. For example, Patent Document 1 discloses a polymer composition containing a thermoplastic elastomer, rubber or bioplastic, and a plasticizer, and the plasticizer is a plant-based raw material, a raw material product based on industrial plants, or a raw material product based on animal-derived fat sources.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-529688 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] For a thermoplastic elastomer composition, excellent anti-fogging properties (low fogging properties) and flexibility are required depending on its use, molding method, etc. However, in Patent Document 1, it is not clear what conditions are required for the composition to have excellent anti-fogging properties and flexibility.

[0010] Therefore, an object of the present invention is to provide a thermoplastic elastomer and a molded article that have excellent anti-fogging properties (low fogging properties) and flexibility and can further reduce the environmental load when using a biomass-derived softening agent.

[0011] Means for Solving the Problems

[0012] The inventors of the present invention conducted in-depth research to solve the above problems, and as a result, found that the above problems can be solved by a thermoplastic elastomer composition containing a polypropylene-based resin, an ethylene-α-olefin-non-conjugated polyene copolymer, and a softening agent in a specific mixing ratio, and the softening agent is a softening agent that satisfies specific conditions, and a molded article containing the thermoplastic elastomer composition, thereby completing the present invention.

[0013] That is, the present invention relates to the following [1] to

[20] . [1]

[0015] A thermoplastic elastomer composition containing the following components (A) to (C) and at least a part thereof is crosslinked.

[0016] (A) 100 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer;

[0017] (B) 10 to 200 parts by mass of a polypropylene-based resin;

[0018] (C) 10 to 200 parts by mass of a softening agent, and the content of alkane-based carbon atoms (%) C P ) of the foregoing softening agent measured according to ASTM D3238-85 or ASTM D2140 is 80% or more and 100% or less. [2]

[0020] The thermoplastic elastomer composition according to [1], wherein the foregoing softening agent (C) includes a biomass-derived softening agent. [3]

[0022] The thermoplastic elastomer composition according to [1], wherein the foregoing softening agent (C) is a biomass-derived softening agent. [4]

[0024] The thermoplastic elastomer composition according to any one of [1] to [3], wherein the content of naphthene-based carbon atoms (%) C N ) of the foregoing softening agent (C) measured further according to ASTM D3238-85 or ASTM D2140 is 20% or less and the content of aromatic hydrocarbon-based carbon atoms (%) C A ) is 5% or less. [5]

[0026] The thermoplastic elastomer composition according to any one of [1] to [4], wherein the polystyrene-reduced weight average molecular weight (Mw) of the foregoing softening agent (C) measured by gel permeation chromatography (GPC) is 900 or more. [6]

[0028] The thermoplastic elastomer composition according to any one of [1] to [5], wherein the evaporation loss of the aforementioned softening agent (C) at 200 °C, normal pressure, and for 1 hour is 0.2% by mass or less. [7]

[0030] The thermoplastic elastomer composition according to any one of [1] to [6], wherein the kinematic viscosity of the aforementioned softening agent (C) at 40 °C is 40 mm 2 / s or more and 150 mm 2 / s or less. [8]

[0032] The thermoplastic elastomer composition according to any one of [1] to [7], wherein the density of the aforementioned softening agent (C) at 15 °C is 865 kg / m 3 or less. [9]

[0034] The thermoplastic elastomer composition according to any one of [1] to [8], wherein the pour point of the aforementioned softening agent (C) is -20 °C or less.

[10]

[0036] The thermoplastic elastomer composition according to any one of [1] to [9], wherein the melt flow rate (MFR, 230 °C, 10 kg load) measured according to JIS K7210 is 1 to 150 g / 10 minutes.

[11]

[0038] The thermoplastic elastomer composition according to any one of [1] to

[10] , wherein the aforementioned polypropylene-based resin (B) is at least one selected from the group consisting of propylene homopolymers, random copolymers of propylene and α-olefins other than propylene, and block copolymers of propylene and α-olefins other than propylene.

[12]

[0040] The thermoplastic elastomer composition according to any one of [1] to

[11] , wherein the aforementioned polypropylene-based resin (B) consists only of a block copolymer of propylene and an α-olefin other than propylene.

[13]

[0042] The thermoplastic elastomer composition according to any one of [1] to

[12] , wherein the melting point of the aforementioned polypropylene-based resin (B) is 80 to 170 °C, and further contains 40 parts by mass or less of the following component (D).

[0043] (D) An ethylene-propylene copolymer having a melting point of 70 °C or less or not observable, and a density of 800 to 900 kg / m 3 .

[14]

[0045] The thermoplastic elastomer composition according to any one of [1] to

[13] further contains a crosslinking agent.

[15]

[0047] In the thermoplastic elastomer composition according to

[14] , 0.05 to 3 parts by mass of the above crosslinking agent is contained relative to 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A).

[16]

[0049] In the thermoplastic elastomer composition according to

[14] , 0.10 to 1 part by mass of the above crosslinking agent is contained relative to 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A).

[17]

[0051] In the thermoplastic elastomer composition according to any one of

[14] to

[16] , the above crosslinking agent is an organic peroxide.

[18]

[0053] A molded article comprising the thermoplastic elastomer composition according to any one of [1] to

[17] .

[19]

[0055] A film or sheet formed from the molded article according to

[18] .

[20]

[0057] An automotive interior material formed from the molded article according to

[19] .

[0058] Advantages of the Invention

[0059] According to the present invention, it is possible to provide an olefin-based thermoplastic elastomer and a molded article that are excellent in anti-fogging properties (low fogging properties) and flexibility, and can further reduce the environmental load when using a softening agent derived from biomass. Detailed Description of the Invention

[0060] Hereinafter, the detailed description of the specific embodiments of the present invention will be given. However, the present invention is not limited to any of the following embodiments, and appropriate modifications can be made within the scope of the object of the present invention for implementation.

[0061] Here, in this specification, the term "polymer" is used to include both homopolymers and copolymers unless otherwise specified.

[0062] In this specification, the numerical range expressed by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0063] In addition, in this specification, when referring to the amounts of the respective components in the composition, in the case where there are multiple substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the multiple substances present in the composition.

[0064] [Thermoplastic elastomer composition]

[0065] The thermoplastic elastomer composition of the present invention contains the following components (A) to (C) and is at least partially crosslinked:

[0066] (A) 100 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer;

[0067] (B) 10 to 200 parts by mass of a polypropylene-based resin;

[0068] (C) 10 to 200 parts by mass of a softening agent, and the content of alkane-based carbon atoms (%) C P of the softening agent measured according to ASTM D3238-85 or ASTM D2140 is 80% or more and 100% or less.

[0069] Hereinafter, the thermoplastic elastomer composition of the present invention will be described in detail.

[0070] [Ethylene-α-olefin-non-conjugated polyene copolymer (A)]

[0071] The ethylene-α-olefin-non-conjugated polyene copolymer (A) (hereinafter also referred to as "copolymer (A)" and sometimes as "component (A)") used in the present invention is a copolymer formed from ethylene, an α-olefin other than ethylene (preferably an α-olefin having 3 to 20 carbon atoms), and a non-conjugated polyene (preferably a non-conjugated diene).

[0072] The aforementioned copolymer (A) can be produced by various known methods using Ziegler-Natta type catalysts or metallocene catalysts.

[0073] The ethylene / α-olefin (molar ratio) in the aforementioned copolymer (A) is usually 85 / 15 to 55 / 45, preferably 83 / 17 to 60 / 40.

[0074] Specific examples of the aforementioned α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 2-methyl-1-propene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 5-methyl-1-hexene. In a preferred embodiment of the present invention, the aforementioned α-olefin is propylene.

[0075] As the aforementioned non-conjugated diene, specifically, examples thereof include cyclic dienes such as dicyclopentadiene, cyclooctadiene, methylene norbornene (e.g., 5-methylene-2-norbornene), ethylidene norbornene (e.g., 5-ethylidene-2-norbornene), methyltetrahydroindene, 5-vinyl-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, norbornadiene;

[0076] linear dienes such as 1,4-hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4,5-dimethyl-1,4-hexadiene, 6-methyl-1,6-octadiene, 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-1,6-undecadiene, 7-methyl-1,6-octadiene. In a preferred embodiment of the present invention, the aforementioned non-conjugated diene is a cyclic diene. Here, as examples of particularly preferred cyclic dienes, 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene can be mentioned.

[0077] The Mooney viscosity ML 1+4 (125 °C) of the aforementioned copolymer (A) is generally 10 to 200, preferably 20 to 160, more preferably 40 to 150, and the iodine value is generally 3 to 25, preferably 5 to 25.

[0078] The aforementioned copolymer (A) can exist in all crosslinked states such as uncrosslinked, partially crosslinked, and fully crosslinked in the thermoplastic elastomer, but in the present invention, it needs to exist in a fully or partially crosslinked state.

[0079] In addition, it is preferred that the kinematic viscosity of the aforementioned copolymer (A) at 40 °C exceeds 500,000 mm 2 / s. Here, "exceeds 500,000 mm 2 / s" is a concept that includes cases where the fluidity is so low that the kinematic viscosity cannot be measured.

[0080] <Polypropylene resin (B)>

[0081] The thermoplastic elastomer composition of the present invention contains a polypropylene-based resin (B) (hereinafter sometimes also referred to as "component (B)"). The polypropylene-based resin (B) used in the present invention is preferably a homopolymer of propylene or a copolymer of propylene and an olefin other than propylene. In the present invention, the polypropylene-based resin (B) is preferably at least one selected from the group consisting of a propylene homopolymer, a random copolymer of propylene and an α-olefin other than propylene, and a block copolymer of propylene and an α-olefin other than propylene. Here, in a particularly preferred embodiment of the present invention, the polypropylene-based resin (B) consists only of a block copolymer of propylene and an α-olefin other than propylene.

[0082] As a suitable raw material olefin other than propylene constituting the polypropylene-based resin (B), an α-olefin having 2 or 4 to 20 carbon atoms is preferred. Specifically, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 2-methyl-1-propene, 3-methyl-1-pentene, 4-methyl-1-pentene, 5-methyl-1-hexene, etc. can be cited. Among these olefins, ethylene is preferred.

[0083] The arrangement of the monomers constituting the polypropylene-based resin (B) is not particularly limited as long as a resinous substance can be obtained, and it can be a random type or a block type. These polypropylene-based resins can be a single type or a combination of two or more types.

[0084] The polypropylene-based resin (B) used in the present invention is preferably a polypropylene-based polymer having a propylene content of 40 mol% or more, and more preferably a polypropylene-based polymer having a propylene content of 50 mol% or more.

[0085] Among these polypropylene-based resins, a propylene homopolymer, a propylene-ethylene block copolymer, a propylene-ethylene random copolymer, a propylene-ethylene-butene random copolymer, etc. are particularly preferred.

[0086] The melting point of the polypropylene-based resin (B) used in the present invention is usually 80 to 170 °C, and preferably in the range of 120 to 170 °C.

[0087] The MFR (ASTM D1238-65T, 230 °C, 2.16 kg load) of the polypropylene-based resin (B) used in the present invention is usually 0.01 to 100 g / 10 minutes, and preferably in the range of 0.05 to 50 g / 10 minutes.

[0088] The polypropylene-based resin (B) used in the present invention preferably has an isotactic structure as the stereostructure, but it can also have a syndiotactic structure, or a structure formed by mixing an isotactic structure and a syndiotactic structure. Or, in addition to these structures, it can further contain a part of an atactic structure.

[0089] The polypropylene-based resin (B) used in the present invention is polymerized by various known polymerization methods.

[0090] In addition, the polypropylene-based resin (B) used in the present invention may be a polymer obtained by using only fossil fuel-derived olefins such as propylene from fossil fuels as raw materials, a polymer obtained by using only biomass-derived olefins such as propylene from biomass as raw materials, or a polymer obtained by using a mixture of fossil fuel-derived olefins and biomass-derived olefins as raw materials, or may also be a mixture of two or more of these polymers.

[0091] Here, fossil fuels refer to substances such as petroleum, coal, natural gas, and shale gas that have been fossilized through the accumulation and pressurization of the remains of animals and plants over hundreds of millions of years. Fossil fuel-derived olefins are olefins obtained from such fossil fuels. Since it has passed a time much longer than the half-life of 5,730 years of 14 C isotope, 14 C cannot be detected from fossil-derived carbon.

[0092] In addition, biomass refers to all renewable natural raw materials and their residues derived from plants or animals, including fungi, yeasts, algae, and bacteria. Biomass-derived olefins are olefins obtained from such biomass. Biomass-derived carbon contains a certain amount of 14 C isotope as carbon (at a ratio of about 10 -12 %).

[0093] With respect to 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A), the content of the polypropylene-based resin (B) is 10 to 200 parts by mass, preferably 15 to 180 parts by mass, more preferably 20 to 150 parts by mass, and still more preferably 25 to 130 parts by mass. Here, when the polypropylene-based resin (B) contains two or more polymers, the total amount of these polymers may be applied to the aforementioned numerical range.

[0094] It should be noted that it is preferred that the kinematic viscosity of the aforementioned polypropylene-based resin (B) at 40 °C exceeds 500,000 mm 2 / s. Here, "exceeds 500,000 mm 2 / s" is a concept that includes cases where the fluidity is low and the kinematic viscosity cannot be measured.

[0095] <Softening agent (C)>

[0096] The content of paraffinic carbon atoms (%C P) is 80% or more and 100% or less. By using such a softening agent (C), the obtained thermoplastic elastomer composition is excellent in anti-fogging property (low fogging property) and flexibility.

[0097] From the viewpoint of compatibility with the polypropylene-based resin in the obtained thermoplastic elastomer composition, and from the viewpoint that the obtained thermoplastic elastomer composition has more excellent anti-fogging property and less flexibility, the content of the above-mentioned alkane-based carbon atoms (%C P ) is preferably 85% or more and 100% or less, more preferably 90% or more and 100% or less, and still more preferably 95% or more and 100% or less.

[0098] In addition, from the above viewpoints, the content of the above-mentioned naphthene-based carbon atoms (C N ) is usually 20% or less (i.e., 0% or more and 20% or less), preferably 15% or less (i.e., 0% or more and 15% or less), more preferably 10% or less (i.e., 0% or more and 10% or less), and still more preferably 5% or less (i.e., 0% or more and 5% or less).

[0099] On the other hand, from the viewpoint of ensuring sufficient heat resistance, the content of the above-mentioned aromatic hydrocarbon-based carbon atoms (%C A ) is usually 5% or less (i.e., 0% or more and 5% or less), preferably 2.0% or less (i.e., 0% or more and 2.0% or less), more preferably 1.0% or less (i.e., 0% or more and 1.0% or less), and still more preferably 0.1% or less (i.e., 0% or more and 0.1% or less).

[0100] The above-mentioned %C P , %C N and %C A are obtained by the measurement method according to ASTM D3238-85 or ASTM D2140. The above-mentioned %C P , %C N and %C A respectively refer to the percentage of the number of alkane carbon atoms, the percentage of the number of naphthene carbon atoms, and the percentage of the number of aromatic hydrocarbon carbon atoms relative to the total number of carbon atoms obtained by the aforementioned measurement method.

[0101] ASTM D3238 - 85 covers the Standard Test Method for Calculation of Carbon Distribution and Structural Group Analysis of Petroleum Oils by the n - d - M Method, which specifies the Ring Analysis based on the n - d - M method. The Ring Analysis based on the n - d - M method is a type of structural group analysis used in the compositional analysis of high - boiling petroleum fractions. It is a method for obtaining the following carbon distribution and ring content from the measured values of the refractive index n, density d, and average molecular weight M of the sample at 20 °C or 70 °C, either by calculation formulas or charts.

[0102] · Carbon distribution

[0103] Aromatic carbon %: %C A

[0104] Naphthenic carbon %: %C N

[0105] Paraffinic carbon %: %C P

[0106] Carbon in ring structures %: %C R =%C A +%C N

[0107] · Ring content

[0108] Number of aromatic rings: R A

[0109] Number of naphthenic rings: R N

[0110] On the other hand, ASTM D2140 covers the Standard Practice for Calculating Carbon - Type Composition of Insulating Oils of Petroleum Origin. In ASTM D2140, the carbon - type composition of the softener (C) can be calculated using viscosity, density, and refractive index, and the aromatic carbon % (%C A )、naphthenic carbon % (%C N ) and paraffinic carbon % (%C P ) can be obtained through ring analysis. In the present invention, even if the aromatic carbon % (%C obtained from ASTM D2140 respectivelyA ) and naphthene carbon % (%C N ) instead of the aromatic carbon % (%C P ) obtained in ASTM D3238 - 85, there is no problem in practical use. A ), naphthene carbon % (%C N ) and paraffin carbon % (%C P ).

[0111] In addition, from the viewpoint of atomization characteristics, the weight - average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) of the softening agent (C) used in the present invention is preferably 900 or more, more preferably 950 or more, further preferably 1000 or more, and particularly preferably 1050 or more. On the other hand, regarding the upper limit value of the aforementioned Mw, there is no particular limitation as long as the object of the present invention is not impaired, but it is preferably 1500 or less.

[0112] From the aspect of atomization characteristics, the evaporation loss of the aforementioned softening agent (C) at 200 °C, normal pressure, and 1 hour is preferably 0.2% by mass or less, more preferably 0.15% by mass or less, and further preferably 0.13% by mass or less. The evaporation loss at 200 °C, normal pressure, and 3 hours is preferably 1.2% by mass or less, more preferably 1.0% by mass or less, and further preferably 0.8% by mass or less. The evaporation loss at 200 °C, normal pressure, and 5 hours is preferably 2.5% by mass or less, more preferably 2.0% by mass or less, and further preferably 1.5% by mass or less. By using a softening agent with an evaporation loss of a certain amount or less as the softening agent (C), the content of volatile components in the thermoplastic elastomer composition of the present invention becomes less, and it has good atomization characteristics.

[0113] It should be noted that the aforementioned evaporation loss of the softening agent (C) is specifically the value measured by the method described in "(6) Heating evaporation loss" in the following examples.

[0114] The kinematic viscosity of the aforementioned softening agent (C) at 40 °C is mostly 500,000 mm 2 / s or less. From the aspects of compatibility with polypropylene - based resins and moldability, it is preferably 200 mm 2 / s or less, more preferably 150 mm 2 / s or less, and further preferably 90 mm 2 / s or less. In addition, the kinematic viscosity of the aforementioned softening agent (C) at 40 °C is preferably 40 mm 2 / s or more, and more preferably 50 mm 2 / s or more.

[0115] It should be noted that the aforementioned kinematic viscosity of the softening agent (C) is specifically the value measured at a predetermined measurement temperature (e.g., 40 °C) according to the measurement method of ASTM D 445.

[0116] From the viewpoint of reducing the weight of the molded body, the density of the aforementioned softening agent (C) at 15 °C is preferably 890 kg / m 3 Hereinafter, more preferably 865 kg / m 3 Hereinafter, further preferably 850 kg / m 3 Hereinafter. In addition, the density of the aforementioned softening agent (C) at 15 °C is preferably 800 kg / m 3 or more, more preferably 820 kg / m 3 or more.

[0117] It should be noted that the aforementioned density of the softening agent (C) is specifically the value measured at a predetermined measurement temperature (e.g., 15 °C) according to the measurement method of ASTM D4052.

[0118] From the viewpoint of good low-temperature characteristics, the pour point of the aforementioned softening agent (C) is preferably -10 °C or lower, more preferably -15 °C or lower, and further preferably -20 °C or lower. In addition, the pour point of the softening agent (C) is usually -50 °C or higher, preferably -40 °C or higher, and more preferably -35 °C or higher.

[0119] It should be noted that the pour point of the softening agent (C) is the value measured according to ASTM D-6749.

[0120] Any softening agent can be used as the aforementioned softening agent (C) as long as it satisfies the above properties. For example, it can be a refined mineral oil, a synthetic oil obtained by polymerizing an olefin-based monomer, a softening agent derived from biomass described later, or a mixture of two or more of them.

[0121] Among these, the aforementioned softening agent (C) preferably contains a softening agent derived from biomass, and more preferably is a softening agent derived from biomass. By using a softening agent derived from biomass as the aforementioned softening agent (C), the resulting thermoplastic elastomer composition not only has excellent fluidity, less hue unevenness, and excellent molding appearance, but also can reliably reduce the environmental load. In addition, the softening agent derived from biomass has a tendency that the density at 15 °C is lower than that of refined mineral oil and synthetic oil (e.g., 865 kg / m 3 or lower). Therefore, when the aforementioned softening agent (C) is a softening agent derived from biomass, this softening agent (C) has a tendency that the density at 15 °C is lower than that of refined mineral oil and synthetic oil (e.g., 865 kg / m 3 or lower), which is also advantageous from the viewpoint of reducing the weight of the obtained molded body.

[0122] The aforementioned softener derived from biomass is a softener obtained from raw materials such as cultivated plants, natural plants, and animal fat sources. The softener (C) may contain not only softeners derived from biomass but also softeners derived from fossil fuels. However, from the aspect of better reducing the environmental load, the softener (C) preferably contains softeners derived from biomass and does not contain softeners derived from fossil fuels. It should be noted that the softener derived from fossil fuels refers to a softener obtained through a manufacturing process including processing and other procedures from fossil fuels such as natural gas.

[0123] The softener derived from biomass obtained from plant or animal fat sources is an organic compound or a mixture of organic compounds obtained through a manufacturing process including procedures such as extraction or processing from the raw materials.

[0124] In most cases, the softener derived from biomass contains various specific organic compounds derived from various organic compounds contained in raw materials such as plants (e.g., sugarcane, rapeseed) and animal fat sources (e.g., butter), and further contains these organic compounds in a specific composition distribution. Therefore, generally speaking, it is difficult for the softener derived from biomass and the softener derived from fossil fuels to have the same chemical composition.

[0125] Preferred plants as raw materials for the softener derived from biomass include, for example, trees, sunflowers, rapeseed, rape, corn, linseed, jojoba, peanuts, coconuts, thistles, castor beans, soybeans, palms, hemp, olives, sugarcane, beets, and other grains.

[0126] Preferred animal fat sources as raw materials for the softener derived from biomass include, for example, butter, lard, tallow, beef fat, herring, sardines, and other animal fats.

[0127] As the raw material for the softener derived from biomass, plants are preferred, and cultivated plants are more preferred.

[0128] As a preferred form of the raw material for the softener derived from biomass, vegetable oils obtained from the aforementioned cultivated plants and other plants are preferred. Preferred vegetable oils include, for example, lignin oil, sunflower oil, rapeseed oil, rape oil, corn oil, hempseed oil, olive oil, linseed oil, soybean oil, palm oil, jojoba oil, etc.

[0129] In addition, as a raw material for the softener derived from biomass, raw materials obtained from the aforementioned cultivated plants and other plants that may contain starch, cellulose, or lignin are another preferred form. Among them, as the raw material, there are raw materials obtained from sugarcane or beets, raw materials obtained from palm oil, raw materials obtained from sunflowers, raw materials obtained from rapeseed, etc.

[0130] The method for manufacturing a softening agent derived from biomass is not particularly limited as long as it uses the above-mentioned plants or the above-mentioned animal fat sources and does not impair the object of the present invention. In an exemplary embodiment of the present invention, a softening agent derived from biomass can be obtained by obtaining an alcohol such as a long-chain aliphatic alcohol from the above-mentioned plants or the above-mentioned animal fat sources, and then modifying the alcohol.

[0131] Compared with a softening agent derived from fossil fuels, a softening agent derived from biomass tends to contain more alkane-based carbon atoms. On the other hand, a softening agent derived from biomass tends to contain no cycloalkane-based carbon atoms and aromatic hydrocarbon-based carbon atoms at all, or only contains a small amount of cycloalkane-based carbon atoms and aromatic hydrocarbon-based carbon atoms compared with a softening agent from fossil fuels.

[0132] As a softening agent derived from biomass, it may contain a plant-derived molecular structure classified as the following (α) to (γ), but from the viewpoint of heat resistance, it is preferably not contained.

[0133] (α) A softening agent containing a fatty acid ester represented by the following formula (α)

[0134] (β) A softening agent containing a triglyceride represented by the following formula (β)

[0135] (γ) A softening agent containing a dimer acid-based compound, i.e., a dimer acid ester, represented by the following formula (γ)

[0136] The softening agent (α) derived from biomass of the above classification (α) is a softening agent containing a fatty acid ester represented by the following formula (α).

[0137] [Chemical Formula 1]

[0138]

[0139] In the above formula (α), R1 is a substituted or unsubstituted aryl group having 1 to 22 carbon atoms, preferably a substituted or unsubstituted phenyl group having 1 to 10 carbon atoms; a substituted or unsubstituted linear or branched alkyl group having 1 to 22 carbon atoms; or a substituted or unsubstituted linear or branched alkylene group having 1 to 3 double bonds, preferably 1 double bond, and having 1 to 22 carbon atoms;

[0140] R2 is a substituted or unsubstituted linear or branched saturated or unsaturated aliphatic hydrocarbon group having 1 to 21 carbon atoms, preferably a linear saturated or unsaturated aliphatic hydrocarbon group having 1 to 21 carbon atoms, more preferably a linear unsaturated aliphatic hydrocarbon group having 1 to 3 double bonds and having 1 to 21 carbon atoms, and further preferably a linear unsaturated aliphatic hydrocarbon group having 1 double bond and having 1 to 17 carbon atoms.

[0141] When R1 is an alkyl group as described above, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, stearyl, or oleyl is preferred, and 2-ethylhexyl, decyl, or oleyl is more preferred.

[0142] In addition, when R1 is an alkylene group having one double bond, the double bond is preferably located at the 9th position of the alkylene group.

[0143] In addition, unless otherwise specified, the number of carbon atoms in the groups that become R1 and R2 is the total number of carbon atoms including the carbon atoms of the substituents and side chains.

[0144] As R1 of the fatty acid ester represented by the above formula (α), a substituted or unsubstituted linear or branched alkyl group having 1 to 22 carbon atoms is preferred, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, stearyl, or oleyl is more preferred, and 2-ethylhexyl, oleyl, or decyl is further preferred.

[0145] As R2 of the fatty acid ester represented by the above formula (α), a substituted or unsubstituted linear or branched saturated or unsaturated aliphatic hydrocarbon group having 1 to 21 carbon atoms is preferred, a linear saturated or unsaturated aliphatic hydrocarbon group having 1 to 21 carbon atoms is more preferred, a linear unsaturated aliphatic hydrocarbon group having 1 to 21 carbon atoms and having 1 to 3 double bonds is further preferred, and a linear unsaturated aliphatic hydrocarbon group having 1 to 17 carbon atoms and having 1 double bond is still further preferred.

[0146] Preferred compounds of the fatty acid ester represented by the above formula (α) include, for example, alkyl arachidonate, alkyl linoleate, alkyl linolenate, alkyl laurate, alkyl myristate, alkyl oleate, alkyl caprate, alkyl stearate, alkyl palmitate, alkyl octanoate, alkyl hexanoate, alkyl butyrate, alkyl behenate, etc.

[0147] Among these fatty acid esters, 2-ethylhexyl oleate, 2-ethylhexyl stearate, decyl oleate, decyl stearate, oleyl oleate, and oleyl stearate are preferred.

[0148] The above fatty acid esters can be used alone or in the form of a mixture of two or more.

[0149] The softening agent (β) derived from biomass of the above classification (β) is a softening agent containing a triglyceride represented by the following formula (β). Triglyceride refers to an ester of glycerol in which all the hydroxyl groups of a fatty acid having 3 hydroxyl groups are esterified.

[0150] [Chemical formula 2]

[0151]

[0152] In the above formula (β), R3, R4, and R5 are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 22 carbon atoms; or a substituted or unsubstituted linear or branched alkylene group having 1 to 22 carbon atoms and having 1 to 3 double bonds, preferably 1 double bond.

[0153] As R3, R4, and R5 of the triglyceride represented by the above formula (β), it is preferred that they are all the same. One preferred form of R3, R4, and R5 of the triglyceride represented by the above formula (β) is an oil group, and another preferred form is an organic group having 17 carbon atoms represented by the following formula (β1).

[0154] [Chemical formula 3]

[0155]

[0156] The biomass-derived softener (γ) of the above classification (γ) is a softener containing a dimer acid-based compound, that is, a dimer acid ester, represented by the following formula (γ). This dimer acid ester is usually a reaction product of dimer acid and a linear or branched saturated alcohol having 1 to 22 carbon atoms or an unsaturated alcohol having 1 to 3 carbon-carbon double bonds.

[0157] [Chemical formula 4]

[0158]

[0159] In the above formula (γ), n is an integer of 1 or more, preferably an integer of 1 to 40, more preferably an integer of 1 to 30, and R6 and R7 are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 22 carbon atoms, preferably methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, stearyl, or oil group.

[0160] The dimer acid ester is an ester of an unsaturated fatty acid dimer. The dimer fatty acid can be obtained by dimerization of each fatty acid. This ester can be obtained by the reaction of the above dimer acid and an alcohol. As the aforementioned alcohol used as a raw material for the dimer acid ester, methanol, 2-ethylhexanol, tridecanol, and oleyl alcohol are preferred.

[0161] When using the aforementioned biomass-derived softeners (α) to (γ) as the biomass-derived softener, only one kind can be used as this softener, or a mixture of two or more kinds can be used as this softener.

[0162] From the viewpoints of suppressing the exudation of the softening agent and ensuring good anti-fogging property, flexibility and processability, the content of the softening agent (C) is 10 to 200 parts by mass, preferably 20 to 180 parts by mass, more preferably 25 to 160 parts by mass, and still more preferably 30 to 150 parts by mass with respect to 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A).

[0163] <Propylene-ethylene copolymer (D)>

[0164] In addition to the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene-based resin (B) and the aforementioned softening agent (C), the thermoplastic elastomer composition of the present invention may further contain a propylene-ethylene copolymer (D) (hereinafter sometimes also referred to as "component (D)").

[0165] The melting point of the propylene-ethylene copolymer (D) that can be used in the present invention is 70°C or lower or not observable, and the density is 800 to 900 kg / m 3 .

[0166] The propylene-ethylene copolymer (D) used in the present invention is preferably a random copolymer of propylene and ethylene.

[0167] The aforementioned propylene-ethylene copolymer (D) preferably satisfies the following (1) and (2).

[0168] (1) It contains 70 mol% or more and less than 90 mol%, preferably 75 to 88 mol% of units derived from propylene, and contains more than 10 mol% and 30 mol% or less, preferably 12 mol% or more to 25 mol% [propylene content + α-olefin content = 100 mol%] of units derived from α-olefins containing ethylene;

[0169] (2) The melting point (Tm) is 70°C or lower, preferably 60°C or lower.

[0170] The propylene-ethylene copolymer (D) used in the present invention generally does not substantially have an unsaturated bond in the main chain.

[0171] In the propylene-ethylene copolymer (D) used in the present invention, "the melting point is not observable" means a so-called amorphous copolymer that does not have a melting point (Tm). Specifically, for example, it also includes a copolymer in which in the measurement of the melting point (Tm) using DSC described below, no melting peak with a heat of fusion (ΔH) of 10 J / g or more is observable within the DSC measurement temperature range of -100 to 200°C.

[0172] The melt flow rate (MFR: measured at 230°C under a load of 2.16 kg) of the propylene-ethylene copolymer (D) used in the present invention is generally in the range of 0.05 to 100 g / 10 minutes, preferably in the range of 0.1 to 50 g / 10 minutes.

[0173] The thermoplastic elastomer composition of the present invention may or may not contain the propylene-ethylene copolymer (D). However, when the thermoplastic elastomer composition of the present invention further contains the propylene-ethylene copolymer (D), the content of the propylene-ethylene copolymer (D) is more than 0 part by mass and 40 parts by mass or less, preferably more than 0 part by mass and 35 parts by mass or less, more preferably more than 0 part by mass and 30 parts by mass or less, and still more preferably more than 0 part by mass and 25 parts by mass or less, based on 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A).

[0174] <Composition of thermoplastic elastomer composition>

[0175] The thermoplastic elastomer composition of the present invention contains the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene resin (B), the aforementioned softening agent (C), and optionally the aforementioned propylene-ethylene copolymer (D), and at least a part thereof is crosslinked.

[0176] The thermoplastic elastomer composition of the present invention preferably satisfies the following requirement (1), and more preferably satisfies the following requirements (1) to (2):

[0177] (1) The melt flow rate (MFR, 230°C, 10 kg load) measured according to JIS K7210 is 1 to 150 g / 10 minutes.

[0178] (2) The Shore A hardness (instantaneous value) measured according to JIS K6253 in the state where three sheets of 2-mm-thick tablets are overlapped to form a 6-mm-thick sheet is 50 to 100.

[0179] The melt flow rate specified in the aforementioned requirement (1) is preferably 1 to 50 g / 10 minutes, more preferably 1 to 30 g / 10 minutes, still more preferably 1 to 20 g / 10 minutes, and particularly preferably 5 to 20 g / 10 minutes.

[0180] The Shore A hardness (instantaneous value) specified in the aforementioned requirement (2) is preferably 40 to 100, more preferably 45 to 97, and still more preferably 50 to 95. Here, the aforementioned Shore A hardness (instantaneous value) can be specifically measured by the method described in the examples below.

[0181] The thermoplastic elastomer composition of the present invention may be composed only of the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene-based resin (B), and the aforementioned softening agent (C) as long as at least a part thereof is crosslinked. Alternatively, it may be composed only of the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene-based resin (B), the aforementioned softening agent (C), and the aforementioned propylene-ethylene copolymer (D). In addition, the thermoplastic elastomer composition of the present invention may further contain other components (hereinafter referred to as "other components") that do not belong to these components (A) to (D) in addition to containing the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene-based resin (B), the aforementioned softening agent (C), and optionally the aforementioned propylene-ethylene copolymer (D).

[0182] Here, the crosslinking of the thermoplastic elastomer composition of the present invention is usually carried out in the presence of a crosslinking agent. Therefore, in a preferred embodiment of the thermoplastic elastomer composition of the present invention, the thermoplastic elastomer composition of the present invention further contains a crosslinking agent described later. In this case, the thermoplastic elastomer composition of the present invention may further contain a crosslinking aid described later.

[0183] Crosslinking agent

[0184] As described above, the thermoplastic elastomer composition of the present invention may further contain a crosslinking agent. Examples of the aforementioned crosslinking agent include commonly used crosslinking agents such as organic peroxides, phenolic resins, sulfur, hydrosilylated organic compounds, amino resins, quinones or their derivatives, amine compounds, azo compounds, epoxy compounds, isocyanates, and thermosetting elastomers. Among them, in the present invention, the aforementioned crosslinking agent is preferably an organic peroxide.

[0185] Specific examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne, 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-butyl perbenzoate, tert-butyl peroxybenzoate, tert-butyl isopropyl carbonate peroxide, diacetyl peroxide, lauroyl peroxide, and tert-butylcumyl peroxide. In a preferred embodiment of the present invention, the aforementioned crosslinking agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne.

[0186] Such crosslinking agents as organic peroxides can be used in an amount of 0.05 to 3 parts by mass, preferably 0.10 to 1 part by mass, based on 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A). When the addition amount of the crosslinking agent, especially the addition amount of the organic peroxide, is within the above range, the resulting thermoplastic elastomer composition tends to have sufficient heat resistance, tensile properties, rubber elasticity and also has a formability of a certain degree or more. When the addition amount of the crosslinking agent, especially the addition amount of the organic peroxide, is less than the above range, the crosslinking degree of the resulting thermoplastic elastomer composition is low, and thus the heat resistance, tensile properties and rubber elasticity are insufficient. On the other hand, when the addition amount is more than the above range, the crosslinking degree of the resulting thermoplastic elastomer composition becomes too high, sometimes resulting in a decrease in formability.

[0187] From the aspect of obtaining a good appearance of the extruded sheet, such crosslinking agents as organic peroxides are further preferably used in an amount less than the above amount, that is, in an amount of 0.10 to 0.30 parts by mass based on 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A).

[0188] Crosslinking aid

[0189] In the present invention, when crosslinking treatment is carried out using the above-mentioned organic peroxide, a crosslinking aid can be added. That is, when the thermoplastic elastomer composition of the present invention contains the above-mentioned organic peroxide as the above-mentioned crosslinking agent, the thermoplastic elastomer composition can further contain a crosslinking aid. Examples of such crosslinking aids include sulfur, p-quinonedioxime, p,p'-dibenzoylquinonedioxime, N-methyl-N-4-dinitrosoaniline, nitrobenzene, diphenylguanidine, trimethylolpropane-N,N'-m-phenylenedimaleimide and other crosslinking aids commonly used in crosslinking treatment using organic peroxides; or polyfunctional methacrylate monomers such as divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate; and polyfunctional vinyl monomers such as vinyl butyrate and vinyl stearate.

[0190] By using the above-mentioned compounds, a uniform and gentle crosslinking reaction can be expected. Especially in the present invention, divinylbenzene is most preferred. Divinylbenzene is easy to handle, has good compatibility with the main components of the above-mentioned crosslinked object, namely ethylene-α-olefin-non-conjugated polyene copolymer and polypropylene resin, and has the function of solubilizing organic peroxides and acts as a dispersant for organic peroxides. Therefore, a thermoplastic elastomer composition with uniform crosslinking effect based on heat treatment and good balance between fluidity and physical properties can be obtained.

[0191] The crosslinking aid as described above can be used in an amount of usually 5 parts by mass or less, preferably 0.05 to 3 parts by mass, relative to 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A).

[0192] In addition, in order to promote the decomposition of the organic peroxide, decomposition promoters such as tertiary amines such as triethylamine, tributylamine, 2,4,6-tris(dimethylamino)phenol, and naphthenates of aluminum, cobalt, vanadium, copper, calcium, zirconium, manganese, magnesium, lead, mercury, etc. can also be used.

[0193] In addition, in the thermoplastic elastomer composition of the present invention, as the above-mentioned "other components", in addition to the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), other rubbers that do not belong to the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), do not belong to the aforementioned polypropylene-based resin (B), and do not belong to the aforementioned propylene-ethylene copolymer (D) (hereinafter referred to as "other rubbers") can be further contained. At this time, the addition amount of the "other rubber" that can be used in the present invention is preferably 50 parts by mass or less relative to 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A).

[0194] As other rubbers, for example, diene rubbers such as styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), natural rubber (NR), butyl rubber (IIR), SEBS, polyisobutylene, etc. can be used.

[0195] Within the scope of not impairing the object of the present invention, the thermoplastic elastomer composition of the present invention, as the aforementioned "other components", in addition to the above-mentioned crosslinking agent, crosslinking aid, and "other rubber", additives such as heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, fillers, colorants, lubricants, etc. can also be contained.

[0196] As a preferred mode, it can be cited that, relative to 100 parts by mass of the elastomer composition of the present invention, 30 parts by mass or less of components other than the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene-based resin (B), the aforementioned softening agent (C), and optionally the aforementioned propylene-ethylene copolymer (D) (that is, the aforementioned "other components") are blended, but the present invention is not limited thereto.

[0197] <Manufacturing method of thermoplastic elastomer composition>

[0198] The thermoplastic elastomer composition of the present invention can be obtained by crosslinking a mixture containing the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene-based resin (B), and the aforementioned softening agent (C). Herein, the aforementioned crosslinking can be carried out by a known dynamic crosslinking method. The dynamic crosslinking method refers to performing dynamic heat treatment in the presence of a crosslinking agent, and "performing dynamic heat treatment" means kneading in a molten state. By performing dynamic heat treatment in the presence of a crosslinking agent, typically, the aforementioned mixture is dynamically crosslinked in the presence of a crosslinking agent (i.e., the aforementioned mixture is kneaded in a molten state in the presence of a crosslinking agent, and at least a part of the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A) is made into a crosslinked state under the state of applying a shearing force to the mixture), whereby a crosslinked thermoplastic elastomer composition can be obtained. Here, the aforementioned crosslinking agent can be incorporated into the mixture containing the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A) and the aforementioned polypropylene-based resin (B) in the form of a crosslinking agent mixture diluted by the aforementioned softening agent (C) and containing the aforementioned crosslinking agent and the aforementioned softening agent (C). Here, the aforementioned crosslinking agent mixture can further contain the aforementioned crosslinking aid. In addition, when using the aforementioned organic peroxide as the aforementioned crosslinking agent, the aforementioned crosslinking agent mixture can further contain the aforementioned organic peroxide.

[0199] When performing the aforementioned crosslinking in the presence of a crosslinking agent, the order of mixing the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene-based resin (B), the aforementioned softening agent (C), the aforementioned crosslinking agent, and the crosslinking aid added as needed is not particularly limited. For example, the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene-based resin (B), and the aforementioned crosslinking agent mixture can be first mixed, and then the aforementioned softening agent (C) can be added.

[0200] In addition, when obtaining a thermoplastic elastomer composition further containing the optional aforementioned propylene-ethylene copolymer (D), a mixture containing the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene-based resin (B), the aforementioned softening agent (C), and the aforementioned propylene-ethylene copolymer (D) can also be obtained by the same method. Such a mixture can be obtained, for example, by adding the aforementioned crosslinking agent or a crosslinking agent mixture containing the aforementioned crosslinking agent and the aforementioned softening agent (C) to a mixture containing the aforementioned ethylene-α-olefin-non-conjugated polyene copolymer (A), the aforementioned polypropylene-based resin (B), and the aforementioned propylene-ethylene copolymer (D). In this case, after the step of adding the aforementioned crosslinking agent mixture, the aforementioned softening agent (C) can also be further added to the obtained mixture.

[0201] The dynamic heat treatment in the present invention is preferably carried out in a non-open device, and further preferably carried out in an inert gas atmosphere such as nitrogen or carbon dioxide. The temperature of the heat treatment is in the range from the melting point of the aforementioned polypropylene resin (B) to 300 °C, usually 150 - 290 °C, preferably 170 - 270 °C. The kneading time is usually 1 - 20 minutes, preferably 1 - 10 minutes. In addition, the applied shear force is in the range of 10 - 10,000 sec ～1 , preferably 100 - 5,000 sec ～1 in terms of shear rate.

[0202] As the kneading device, a mixing roll, a high-intensity mixer (such as a Banbury mixer, a kneader), a single-screw or twin-screw extruder, etc. can be used, preferably a non-open device, and a twin-screw extruder is particularly preferred.

[0203] The thermoplastic elastomer of the present invention is preferably heat-treated statically in hot air after the above-mentioned dynamic heat treatment. The heat treatment is preferably carried out at 80 - 130 °C for about 1 - 10 hours. By this heat treatment, residues of crosslinking agents, etc. can be removed, the odor of the obtained product can be reduced, or a product with good atomization property can be obtained.

[0204] [Molded article]

[0205] The molded article obtained in the present invention contains the aforementioned thermoplastic elastomer composition of the present invention. The aforementioned molded article can be made into a film or a sheet. As the use of the aforementioned molded article, interior materials for automobiles can be cited. The aforementioned molded article can be suitably used as the skin layer of interior materials for automobiles, for example.

[0206] Such a molded article of the present invention can be obtained by molding the aforementioned thermoplastic elastomer composition using various molding methods. Examples of the aforementioned molding methods include injection molding, extrusion molding, vacuum molding, pressure-air molding, blow molding, calendering molding, foam molding, etc. Since the thermoplastic elastomer composition of the present invention contains an ethylene-α-olefin-non-conjugated polyene copolymer (A), a polypropylene resin (B), and a softening agent (C), it has excellent high-temperature fluidity and extrusion moldability, and thus can be molded using molding devices conventionally used in compression molding, transfer molding, injection molding, extrusion molding, etc.

[0207] For example, when manufacturing interior materials for automobiles from the aforementioned thermoplastic elastomer composition, it can usually be manufactured according to the following conventional method.

[0208] (1) Supply to a plastic processing machine such as an extrusion molding machine with a T-die head, a calendering molding machine, etc., and mold it into a desired shape such as a sheet.

[0209] (2) Mold it into a desired shape by injection molding.

[0210] On the skin layer of the interior material for automobiles of the present invention, a surface layer containing at least one polymer selected from the group consisting of polyurethane, saturated polyester, acrylate resin, polyvinyl chloride, and isocyanate resin can be provided.

[0211] As the saturated polyester used for forming such a surface layer, polyethylene terephthalate, polybutylene terephthalate, and their derivatives can be used. In addition, as the acrylate resin, poly(methyl)methacrylate, poly(isobutyl methacrylate), poly(2-ethylhexyl methacrylate), etc. can be used. Further, as the isocyanate resin, polyhexamethylene diisocyanate, polyisophorone diisocyanate, etc. can be used.

[0212] Such a surface layer is preferably 300 μm or less. A primer layer can be interposed between the skin layer and such a surface layer.

[0213] Furthermore, the interior material for automobiles of the present invention can form a laminate with a polyolefin foam or a laminate with a polyolefin resin. As the polyolefin used herein, for example, polyethylene, polypropylene, etc. can be cited. As the polypropylene, the polypropylene-based resin used in the production of the thermoplastic elastomer composition of the present invention can be cited.

[0214] Such a laminate is manufactured, for example, by extruding the thermoplastic elastomer composition using an extruder with a T-die, passing the extruded sheet-like thermoplastic elastomer composition in a molten state between a pair of rolls in a state of being laminated with a polyolefin foam sheet, or by sequential injection molding of a polyolefin resin and a thermoplastic elastomer.

[0215] The interior material for automobiles of the present invention is mainly used as the skin layer of door trims, instrument panels, ceilings, steering wheels, console boxes, seats, etc.

[0216] Examples

[0217] Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. It should be noted that the physical properties in the examples were measured as follows.

[0218] [Measurement method]

[0219] (1) Melt flow rate (MFR)

[0220] The melt flow rate of the thermoplastic elastomer composition obtained in the examples and comparative examples was measured according to JIS K 7210 at 230 °C under a load of 10 kg.

[0221] (2) Production of tablets

[0222] Using a hot press, the pellets of the thermoplastic elastomer compositions obtained in the examples and comparative examples were pressed (pressing temperature: 190 °C, cooling temperature: 20 °C, preheating time: 6 minutes, pressure melting time: 4 minutes). As a result of the pressing process, for each composition, a pressed sheet in the form of a flat plate with a length of 20 cm × width of 20 cm × thickness of 2 mm was obtained.

[0223] (3) Shore A hardness

[0224] Using the 2-mm-thick pressed sheet produced by the above method in the foregoing "(2) Production of pressed sheet", in accordance with JIS K6253, the Shore A hardness (instantaneous value) (hereinafter referred to as "A hardness") was determined using a hardness tester. Here, the measurement of the Shore A hardness (instantaneous value) was carried out on a test piece formed by laminating three 2-mm-thick pressed sheets produced in the above (2).

[0225] (4) Tensile properties (tensile test)

[0226] Using the 2-mm-thick pressed sheet produced by the above method in the foregoing "(2) Production of pressed sheet", the following items were measured in accordance with the method of JIS K6301.

[0227] M100: Stress at 100% elongation

[0228] TB: Tensile strength

[0229] EB: Elongation at break

[0230] (5) Fogging property

[0231] (a) Regarding the thermoplastic elastomer composition

[0232] In accordance with DIN 75201, using 10 g of the pellets of the thermoplastic elastomer compositions obtained in the examples and comparative examples, a test was carried out at "100 °C × 5 hours" to measure the haze of the glass (haze and gloss, %).

[0233] (b) Regarding the softener

[0234] The measurement of the fogging property of the softener was carried out as follows: A test was carried out in accordance with VDA 278, and the peaks detected above the baseline were integrated to calculate the FOG value (μg / g).

[0235] (6) Heating loss on evaporation

[0236] (a) Regarding the thermoplastic elastomer composition

[0237] The tablets with a thickness of 2 mm produced by the method described in the aforementioned “(2) Production of tablets” are cut into a size of 60×40 mm, and the weight (mass) (W0) before heating is measured. Then, the tablets are heated using an oven (Gill type aging tester: manufactured by Ueshima Seisakusho Co., Ltd., AG-1115), and the weight (mass) (W1) after cooling at room temperature for 1 hour is measured. The difference (W0 - W1) between the weight (mass) (W0) before heating and the weight (mass) (W1) after the aforementioned heating is calculated respectively, and the percentage of the aforementioned difference (W0 - W1) relative to the weight (mass) (W0) before heating is taken as the heating evaporation loss.

[0238] The aforementioned heating is carried out for each of the three conditions of “100 °C × 100 hours, in air”, “100 °C × 200 hours, in air” and “100 °C × 300 hours, in air”, and the heating evaporation loss under each condition is obtained.

[0239] (b) Regarding the softening agent

[0240] The softening agent as a sample is weighed, and the weight (mass) (W0) before heating is measured. Then, the softening agent is heated using an oven (Gill type oven: manufactured by Toyo Seiki Seisakusho Co., Ltd., ACR-60), and the weight (mass) (W1) after cooling at room temperature for 1 hour is measured. The difference (W0 - W1) between the weight (mass) (W0) before heating and the weight (W1) after the aforementioned heating is calculated respectively, and the percentage of the aforementioned difference (W0 - W1) relative to the weight (mass) (W0) before heating is taken as the heating evaporation loss.

[0241] The aforementioned heating is carried out for each of the three conditions of “200 °C × 1 hour, in air”, “200 °C × 3 hours, in air” and “200 °C × 5 hours, in air”, and the heating evaporation loss under each condition is obtained.

[0242] (7) Physical properties of ethylene-α-olefin-non-conjugated polyene copolymer (A)

[0243] (7-1) Composition (content of each structural unit)

[0244] The mass fraction (mass %) of each structural unit of ethylene-α-olefin-non-conjugated polyene copolymer (A) is obtained based on 13 the measured values of C-NMR. The measured values are obtained by measuring the 13 C-NMR spectrum of the copolymer using an ECX400P type nuclear magnetic resonance apparatus (manufactured by JEOL Ltd.) under the conditions of measurement temperature: 120 °C, measurement solvent: ortho-dichlorobenzene / deuterated benzene = 4 / 1, and number of accumulations: 8000 times.

[0245] (7-2) Iodine value

[0246] The iodine value of the ethylene-α-olefin-non-conjugated polyene copolymer (A) is determined by titration. Specifically, it is carried out by the following method.

[0247] Dissolve 0.5 g of the copolymer in 60 ml of carbon tetrachloride, add a small amount of Wijs reagent and 20% potassium iodide solution, and titrate with 0.1 mol / L sodium thiosulfate solution. Near the end point, add starch indicator and titrate while stirring well until the light purple color disappears. Calculate the number of grams of iodine as the amount of halogen consumed per 100 g of the sample.

[0248] (7-3) Mooney viscosity

[0249] The Mooney viscosity ML of the ethylene-α-olefin-non-conjugated polyene copolymer (A) 1+4 (at 125 °C) is measured at 125 °C according to the measurement method of ASTM D1646-19a.

[0250] (8) Physical properties of the softening agent

[0251] (8-1) Kinematic viscosity

[0252] The kinematic viscosity of the softening agent is measured at 40 °C and 100 °C respectively according to the measurement method of ASTM D 445.

[0253] (8-2) Density

[0254] The density of the softening agent is measured at 15 °C according to the measurement method of ASTM D 4052.

[0255] (8-3) Pour point

[0256] The pour point of the softening agent is measured according to ASTM D-6749.

[0257] (8-4) Hydrocarbon structure

[0258] For the softening agent, the content of naphthenic carbon atoms (%C N )(proportion of naphthenic carbon atoms), the content of paraffinic carbon atoms (%C P )(content of paraffinic carbon atoms), and the content of aromatic carbon atoms (%C A )(proportion of aromatic carbon atoms) are measured according to ASTM D2140.

[0259] It should be noted that in the following examples and comparative examples, the proportion of naphthenic carbon atoms, the content of paraffinic carbon atoms, and the proportion of aromatic carbon atoms were measured according to ASTM D2140, but they can also be measured according to ASTM D3238-85 instead.

[0260] (8-5) Molecular weight distribution

[0261] For the softening agent, gel permeation chromatography (GPC) is carried out based on the following conditions to determine the relative molecular weight (polystyrene-equivalent molecular weight) and its weight fraction (dW / dlogM) at each elution time, prepare a molecular weight distribution curve, and determine the weight-average molecular weight Mw, number-average molecular weight Mn, and Mw / Mn in terms of polystyrene conversion.

[0262] Measuring model: manufactured by Tosoh Corporation (gel permeation chromatograph HLC-8321GPC)

[0263] Column: (2 × TSKgel GMH6-HT + 2 × TSKgel GMH6-HTL (both 7.5 mm I.D. × 30 cm, manufactured by Tosoh Corporation))

[0264] Solvent: o-dichlorobenzene; ODCB (containing 0.025% BHT)

[0265] Column temperature: 140 °C

[0266] Concentration: 0.1%

[0267] Flow rate: 1.0 mL / minute

[0268] Detector: differential refractometer (RI)

[0269] Column calibration: monodisperse polystyrene (manufactured by Tosoh Corporation); #3std set

[0270] Molecular weight conversion: polystyrene conversion / standard conversion method

[0271] [Raw materials]

[0272] The raw materials used in the following examples and comparative examples are as described below.

[0273] <(A) Ethylene-α-olefin-non-conjugated polyene copolymer>

[0274] As the ethylene-α-olefin-non-conjugated polyene copolymer (A) (component (A)), an ethylene-propylene-ENB copolymer (A-1) was prepared according to Production Example 1 below.

[0275] [Production Example 1]

[0276] Using a 300-liter polymerization vessel with a stirring blade, the synthesis of a terpolymer composed of ethylene, propylene, and 5-ethylidene-2-norbornene (ENB) was continuously carried out at a temperature of 60 °C.

[0277] At this time, hexane (feed rate: 26.5 kg / h) was used as the polymerization solvent, and ethylene was fed at a rate of 4.6 kg / h, propylene at a rate of 3.0 kg / h, ENB at a rate of 420 g / h, and hydrogen at a rate of 2 standard liters / h continuously to the polymerizer. While maintaining the polymerization pressure at 1.6 MPa-G, the compound (tert-butylamide)-dimethyl(η5-2-methyl-s-indeno-1-yl)silane titanium(II) 1,3-pentadiene represented by the following formula as the main catalyst was continuously fed to the polymerizer at a rate such that the feed rate became 0.003 mmol / h.

[0278] [Chemical Formula 5]

[0279]

[0280] (C6H5)3CB(C6F5)4 as the cocatalyst was fed continuously to the polymerizer at a rate of 0.017 mmol / h, and triisobutylaluminum as the organoaluminum compound was fed continuously at a rate of 10 mmol / h.

[0281] Thereby, a polymerization solution containing 17.2% by weight of ethylene-propylene-ENB copolymer (A-1) was obtained (polymerization time: 2.12 hours). The obtained polymerization solution was poured into a large amount of methanol to precipitate the copolymer (A-1), and the precipitate was dried under reduced pressure at 80 °C for 24 hours to separate the copolymer (A-1).

[0282] The physical properties of the obtained copolymer (A-1) (hereinafter referred to as "A-1") are as follows.

[0283] (Physical Properties of A-1)

[0284] Ethylene unit content: 66% by mass

[0285] Iodine value: 9.8

[0286] Mooney viscosity ML 1+4 (at 125 °C): 61

[0287] [Production Example 2]

[0288] The monomer feed rates were adjusted and oil was added, and otherwise, the same treatment as in Production Example 1 was carried out to obtain a copolymer (A-2) containing ethylene, propylene, and ENB.

[0289] The physical properties of the obtained copolymer (A-2) (hereinafter referred to as "A-2") are as follows.

[0290] (Physical Properties of A-2)

[0291] Ethylene unit content: 64% by mass

[0292] Iodine value: 11.5

[0293] Mooney viscosity ML 1+4 (at 125°C): 51

[0294] Oil content: 40 parts by mass of rubber softener (C'-1) (manufactured by Idemitsu Kosan Co., Ltd., trade name "Diana Process Oil PW-100") relative to 100 parts by mass of rubber

[0295] <(B) Polypropylene resin>

[0296] As the polypropylene resin (B) (component (B)), the following propylene-ethylene block copolymer (B-1) (hereinafter referred to as "B-1") is used.

[0297] (B-1) Propylene-ethylene block copolymer (manufactured by Total Atofina, trade name "PPC 9760", MFR (ISO1133; 230°C, 2.16 kg load) = 25 g / 10 min, melting point (ISO 3146) = 165°C)

[0298] <(C) Softener and other softeners>

[0299] As the softener (C) (component (C)), a softener (C-1) (manufactured by Hansen&Rosenthal, trade name "VIVA-B-FIX10227") (hereinafter referred to as "C-1") having the physical properties shown in Table 1 below is used.

[0300] In addition, as other softeners that do not belong to the softener (C), the following softeners (C'-1), (C'-2) and (C'-3) having the physical properties shown in Table 1 below are used:

[0301] Softener (C'-1) (manufactured by Idemitsu Kosan Co., Ltd., trade name "Diana Process Oil PW-100") (hereinafter referred to as "C'-1");

[0302] Softener (C'-2) (manufactured by Hansen&Rosenthal, trade name "PIONIER 2071P") (hereinafter referred to as "C'-2");

[0303] Softener (C'-3) (manufactured by Hansen&Rosenthal China, trade name "PIONIER 2275") (hereinafter referred to as "C'-3").

[0304] [Table 1]

[0305] [Table 1]

[0306]

[0307] <(D) Propylene-ethylene copolymer>

[0308] As the propylene-ethylene copolymer (D) (component (D)), the following propylene-ethylene copolymer (D-1) (hereinafter referred to as "D-1") is used.

[0309] (D-1) 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 min, density 863 kg / m 3 )

[0310] <Crosslinking agent and crosslinking aid>

[0311] Crosslinking agent: Organic peroxide (2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne, trade name: PERHEXYNE 25B, manufactured by NOF Corporation, Japan)

[0312] Crosslinking aid: Divinylbenzene (trade name: DVB-810, manufactured by Nippon Steel Chemical & Material Co., Ltd.)

[0313] The above crosslinking agent and the above crosslinking aid are used in the form of a crosslinking agent mixture obtained by mixing 100 parts by mass of the crosslinking aid and 100 parts by mass of the softening agent with respect to 100 parts by mass of the crosslinking agent. As the softening agent used in the above mixing, the above softening agent (C-1) or the above softening agent (C'-1) described in the above "(C) Softening agent and other softening agents" is used.

[0314] [Example 1]

[0315] Using a Henschel mixer, 100 parts by mass of the above ethylene-α-olefin-non-conjugated polyene copolymer (A-1), 100 parts by mass of the above polypropylene resin (B-1), and a crosslinking agent mixture containing 0.28 parts by mass of an organic peroxide (manufactured by NOF Corporation, Japan, trade name: PERHEXYNE 25B) as a crosslinking agent, 0.28 parts by mass of divinylbenzene as a crosslinking aid, and 0.28 parts by mass of the softening agent (C-1) were thoroughly mixed.

[0316] For the aforementioned mixture, using a twin-screw extruder (model KTX-46, manufactured by Kobe Steel, Ltd., barrel temperature: C1 = 110 °C, C2 = 120 °C, C3 = 140 °C, C4 = 140 °C, C5 = 150 °C, C6 = 160 °C, C7–C8 = 180 °C, C9–C14 = 230 °C, die temperature: 200 °C), while injecting a softening agent (C-1) into the barrel, pelletization was carried out to obtain pellets of the thermoplastic elastomer composition.

[0317] For the obtained pellets, various physical properties were measured according to the method described in the above “Measurement Method”.

[0318] The results of the physical property evaluation are shown in Table 2 below.

[0319] [Comparative Examples 1–3]

[0320] Except for changing the raw materials and compounding amounts used as described in Table 2 below, pellets of the thermoplastic elastomer composition were produced in the same manner as in Example 1.

[0321] For the obtained pellets, various physical properties were measured according to the method described in the above “Measurement Method”.

[0322] The results of the physical property evaluation are shown in Table 2 below.

[0323] [Table 2]

[0324] [Table 2]

[0325]

[0326] [Example 2, Comparative Examples 4–5]

[0327] Except for changing the raw materials and compounding amounts used as described in Table 3 below, pellets of the thermoplastic elastomer composition were produced in the same manner as in Example 1. Here, in Table 3, regarding the compounding amount of the copolymer (A-2), the value shown in the upper row represents the total amount as the oil-extended rubber, and the italicized value in parentheses in the lower row represents the copolymer component amount (i.e., the amount remaining after removing the oil contained in the oil-extended rubber from the total amount as the oil-extended rubber).

[0328] [Table 3]

[0329] [Table 3]

[0330]

Claims

1. A thermoplastic elastomer composition which contains the following components (A) to (C), and at least a part thereof is crosslinked, (A) 100 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer; (B) 10 to 200 parts by mass of a polypropylene-based resin; (C) 10 to 200 parts by mass of a softening agent, wherein the content of alkane-based carbon atoms of the softening agent measured according to ASTM D3238-85 or ASTM D2140, i.e., %C P is 80% or more and 100% or less.

2. The thermoplastic elastomer composition according to claim 1, wherein The softening agent (C) contains a biomass-derived softening agent.

3. The thermoplastic elastomer composition according to claim 1, wherein The softening agent (C) is a biomass-derived softening agent.

4. The thermoplastic elastomer composition according to claim 1, wherein, Furthermore, the content of naphthenic hydrocarbon-based carbon atoms, i.e., %C, of the softening agent (C) measured according to ASTM D3238-85 or ASTM D2140 N is 20% or less, and the content of aromatic hydrocarbon-based carbon atoms, i.e., %C A is 5% or less.

5. The thermoplastic elastomer composition according to claim 1, wherein The polystyrene-reduced weight-average molecular weight Mw of the softening agent (C) measured by gel permeation chromatography (GPC) is 900 or more.

6. The thermoplastic elastomer composition according to claim 1, wherein The evaporation loss of the softening agent (C) at 200 °C, normal pressure, and for 1 hour is 0.2% by mass or less.

7. The thermoplastic elastomer composition according to claim 1, wherein, The kinematic viscosity of the softening agent (C) at 40 °C is 40 mm 2 / s or more and 150 mm 2 / s or less.

8. The thermoplastic elastomer composition according to claim 1, wherein The density of the softening agent (C) at 15 °C is 865 kg / m 3 or less.

9. The thermoplastic elastomer composition according to claim 1, wherein The pour point of the softening agent (C) is -20 °C or lower.

10. The thermoplastic elastomer composition according to claim 1, wherein The melt flow rate (MFR) at 230 °C and a load of 10 kg measured according to JIS K7210 is 1 to 150 g / 10 min.

11. The thermoplastic elastomer composition according to claim 1, wherein, The polypropylene-based resin (B) is at least one selected from the group consisting of a propylene homopolymer, a random copolymer of propylene and an α-olefin other than propylene, and a block copolymer of propylene and an α-olefin other than propylene.

12. The thermoplastic elastomer composition according to claim 1, wherein, The polypropylene-based resin (B) consists only of a block copolymer of propylene and an α-olefin other than propylene.

13. The thermoplastic elastomer composition according to claim 1, wherein The melting point of the polypropylene-based resin (B) is 80 to 170 °C, and it further contains 40 parts by mass or less of the following component (D), (D) An ethylene-propylene copolymer having a melting point of 70 °C or lower or not observable and a density of 800 to 900 kg / m 3 .

14. The thermoplastic elastomer composition according to claim 1, which further contains a crosslinking agent.

15. The thermoplastic elastomer composition according to claim 14, wherein, 0.05 to 3 parts by mass of the crosslinking agent is contained relative to 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A).

16. The thermoplastic elastomer composition according to claim 14, wherein, 0.10 to 1 part by mass of the crosslinking agent is contained relative to 100 parts by mass of the ethylene-α-olefin-non-conjugated polyene copolymer (A).

17. The thermoplastic elastomer composition according to claim 14, wherein, The crosslinking agent is an organic peroxide.

18. A molded article which contains the thermoplastic elastomer composition according to any one of claims 1 to 17.

19. A film or sheet which is formed from the molded article according to claim 18.

20. An automotive interior material which is formed from the molded article according to claim 19.

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