JP7049062B2 - Dynamically crosslinked thermoplastic elastomer composition - Google Patents

Description

The present invention relates to a dynamically crosslinked thermoplastic elastomer composition having excellent mechanical strength and compression set, and a molded body, a member for an automobile, a member for a building material, and the like using the same.

Conventionally, in automobile parts, electric / electronic parts, building parts, etc., extruded vulcanized molded products made of a rubber compound of ethylene / propylene / non-conjugated diene ternary copolymer (EPDM) are required to have low hardness and rubber elasticity. It was commonly used in the parts to be used. However, in recent years, from the viewpoint of productivity, environmental friendliness and weight reduction, thermoplastic elastomer compositions that do not require a vulcanization step have begun to be used.

As the thermoplastic elastomer composition, for example, a thermoplastic elastomer composition obtained by dynamically heat-treating a mixture containing a polypropylene resin and an ethylene / α-olefin copolymer in the presence of a cross-linking agent can be used in the vulcanization step. Although it is unnecessary, it exhibits characteristics as a rubber-like soft material, and is known to have molding processability similar to that of a thermoplastic resin. Therefore, from the viewpoint of rationalization of manufacturing process and recyclability, it is attracting attention in a wide range of fields such as automobile parts, building materials, home appliances, medical equipment parts, electric wires, and miscellaneous goods.

For example, Patent Document 1 includes ethylene / propylene / non-conjugated polyene copolymer rubber, paraffin-based process oil, carbon black master batch, and the like, and organic peroxide and divinylbenzene are contained in the extruder. Described are dynamically crosslinked thermoplastic elastomer compositions.

On the other hand, in Patent Documents 2 and 3, various performances at the time of injection foam molding, for example, foaming characteristics, flexibility, heat resistance, etc., can be obtained by blending the thermoplastic elastomer composition with modified polypropylene exhibiting strain curability. Techniques for improvement are described.

Japanese Unexamined Patent Publication No. 2007-070387 Japanese Unexamined Patent Publication No. 2011-102028 JP-A-2015-098542

However, in general, the conventional thermoplastic elastomer composition is not sufficient in that it is inferior in rubber elasticity with compressive permanent strain as an index as compared with vulcanized rubber, and higher compressive permanent strain is required. The replacement with vulcanized rubber has not progressed in severe applications. Therefore, there is a demand for a thermoplastic elastomer composition having improved rubber elasticity without impairing basic performance such as mechanical strength.

On the other hand, Patent Documents 2 and 3 only disclose improvements in various performances in injection foam molding by blending modified polypropylene exhibiting strain curability.

The present invention has been made in view of the above problems, and an object thereof is a novel dynamically crosslinked thermoplastic elastomer composition having excellent mechanical strength and compression set, and a molded product and an automobile using the same. The present invention is to provide members for materials, members for building materials, and the like.

It should be noted that the present invention is not limited to the above-mentioned purpose, and it is an action and effect derived by each configuration shown in the embodiment for carrying out the invention described later, and it is also possible to exert an action and effect which cannot be obtained by the conventional technique. It can be positioned as another purpose.

As a result of diligent studies to solve the above problems, the present inventors have found that a dynamically crosslinked thermoplastic elastomer composition having a predetermined compounding composition can solve the above problems, and have reached the present invention. That is, the present invention provides various specific embodiments shown below.

[1] A dynamically crosslinked thermoplastic elastomer composition comprising the following components (A), component (B), component (C) and component (D).
Component (A): Ethylene / α-olefin / non- conjugated diene copolymer rubber Component (B): Modified polypropylene exhibiting strain curability Component (C): Cross-linking agent Component (D): Hydrocarbon-based rubber softener

[2] The dynamically crosslinked thermoplastic elastomer composition according to [1], which further contains a component (E): a polypropylene-based resin.

[3] The dynamically crosslinked thermoplastic elastomer composition according to [2], wherein the content ratio of the components (B) and (E) in terms of solid content is 99: 1 to 1:99.

[4] The component (A) is contained in an amount of 50 to 90 parts by mass and the component (B) is contained in an amount of 10 to 50 parts by mass with respect to 100 parts by mass of the total amount of the components (A) to (B) [1] to [ 3] The dynamically crosslinked thermoplastic elastomer composition according to any one of the items.

[5] The component (B) has a melt flow rate of 0.1 to 250 g / 10 min (MFR, 230 ° C., load 21.2 N, JIS K7210 compliant) and a melt tension of 1.0 to 20 cN [ 1] The dynamically crosslinked thermoplastic elastomer composition according to any one of [4].

[6] The component (C) contains at least one selected from the group consisting of organic peroxides, phenolic resins, polyfunctional vinyl compounds, polyfunctional (meth) acrylate compounds, and tin chloride [1] to [ 5] The dynamically crosslinked thermoplastic elastomer composition according to any one of the items.

[7] The dynamically crosslinked thermoplastic elastomer composition according to any one of [1] to [6], wherein the content of the component (C) is 0.05 to 20% by mass.

[8] In any one of [1] to [7], the content ratio of the component (D) is 10 to 200 parts by mass with respect to a total of 100 parts by mass of the components (A) and (B). The dynamically crosslinked thermoplastic elastomer composition according to the above.

[9] A molded product obtained by molding the dynamically crosslinked thermoplastic elastomer composition according to any one of [1] to [8].

[10] An automobile member obtained by molding the dynamically crosslinked thermoplastic elastomer composition according to any one of [1] to [8].

[11] A member for building materials obtained by molding the dynamically crosslinked thermoplastic elastomer composition according to any one of [1] to [8].

According to the present invention, it is possible to provide a novel dynamically crosslinked thermoplastic elastomer composition having excellent mechanical strength and compression set, and a molded body, an automobile member, a building material member and the like using the same. can. The dynamically crosslinked thermoplastic elastomer composition of the present invention and the molded article using the same are used for various applications exposed to harsh usage environments where better mechanical strength and rubber elasticity are required. Can be expected to develop.

Hereinafter, embodiments of the present invention will be described in detail. The following embodiments are examples (representative examples) of the embodiments of the present invention, and the present invention is not limited to the following description. The present invention can be arbitrarily modified and carried out without departing from the gist thereof. Further, in the present specification, when a numerical value or a physical property value is inserted before and after using "-", it is used as including the values before and after that. Further, the (co) polymer is used in the sense of including both a homopolymer composed of only one polymer component and a copolymer composed of two or more copolymer components.

[Thermoplastic Elastomer Composition]
The thermoplastic elastomer composition of the present embodiment is a dynamically crosslinked thermoplastic elastomer composition containing at least the following components (A), component (B), components (C) and (D).
Component (A): Ethylene / α-olefin / non- conjugated diene copolymer rubber Component (B): Modified polypropylene exhibiting strain curability Component (C): Cross-linking agent Component (D): Hydrocarbon-based rubber softener

The dynamically crosslinked thermoplastic elastomer composition is obtained by dynamically heat-treating a resin composition containing the components (A), (B) and (D) in the presence of the component (C). be. By performing such dynamic cross-linking, a thermoplastic elastomer composition having good mechanical strength and excellent rubber elasticity with compression set as an index is realized.

[Ingredient (A)]
The ethylene / α-olefin / non- conjugated diene copolymer rubber of the component (A) is a copolymer containing ethylene, an α-olefin, and a non-conjugated diene compound as copolymerization components. There are two types of ethylene / α-olefin / non- conjugated diene copolymer rubber, oil-extended type and non-oil-extended type. The ethylene / α-olefin / non- conjugated diene copolymer rubber used in the component (A) is In the present embodiment, a non-oil-extending type copolymer rubber is intended, but an oil-extending type can also be preferably used. That is, in the present invention, the ethylene / α-olefin / non- conjugated diene copolymer rubber of the component (A) can be used in either an oil-extended type or a non-oil-extended type. That is, it may be referred to as a mixture of ethylene / α-olefin / non- conjugated diene copolymer rubber and a softening agent for hydrocarbon-based rubber (hereinafter, referred to as “oil-extended ethylene / α-olefin / non- conjugated diene copolymer rubber”). It is also possible to use only one type of oil-extended type alone, two or more types in any combination and ratio, or an oil-extended type and a non-oil-extended type in any combination and ratio. ..

Examples of the α-olefin in the component (A) include propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 1-. Examples thereof include α-olefins having 3 to 20 carbon atoms, more preferably 3 to 8 carbon atoms such as hexene, 4-methyl-1-hexene, 1-heptene, 1-octene, 1-decene and 1-octadecene. It is not particularly limited to these. Among these, propylene, 1-butene, 3-methyl-1-butene and 1-pentene are preferable, and propylene and 1-pentene are more preferable, from the viewpoint of cross-linking property by the cross-linking agent at the time of dynamic cross-linking and suppression of bloom-out. Butene. As the α-olefin, only one type can be used alone, or two or more types can be used in any combination and ratio.

Examples of the non-conjugated diene in the component (A) include dicyclopentadiene, 1,4-hexadiene, cyclohexadiene, cyclooctadiene, dicyclooctadiene, 1,6-octadiene, 5-methyl-1,4-hexadiene. , 3,7-dimethyl-1,6-octadene, 1,3-cyclopentadiene, 1,4-cyclohexadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl Echiliden norbornene such as -1,6-octadiene, tetrahydroinden, methyltetrahydroinden, 5-isopropylidene-2-norbornene, 5-vinyl-norbornene, vinylidene norbornene, 5-ethylidene-2-norbornene (ENB), 5-methylene -2-Methylenenorbornene such as norbornene (MNB) and the like can be mentioned, but the present invention is not particularly limited thereto. Among these, dicyclopentadiene, ethylidene norbornene and vinylidene norbornene are preferable, and dicyclopentadiene, 5-ethylidene-2-norbornene and vinylidene norbornene are more preferable from the viewpoint of cross-linking property by the cross-linking agent at the time of dynamic cross-linking. .. As the non-conjugated diene, only one type can be used alone, or two or more types can be used in any combination and ratio.

Specific examples of the ethylene / α-olefin / non- conjugated diene copolymer rubber include ethylene / propylene / non-conjugated diene copolymer rubber (EPDM), ethylene / 1-butene / non-conjugated diene rubber, and ethylene / propylene / 5-. Ethylene-2-norbornene copolymer rubber, ethylene / propylene / dicyclopentadiene copolymer rubber, ethylene / propylene / 1,4-hexadiene copolymer rubber, ethylene / propylene / 5-vinyl-2-norbornene copolymer Examples thereof include rubber, but the present invention is not particularly limited thereto. Among these, ethylene-propylene-non-conjugated diene copolymer rubber (EPDM) is preferable from the viewpoint of cross-linking property by the cross-linking agent at the time of dynamic cross-linking and suppression of bloom-out. As the ethylene / α-olefin / non- conjugated diene copolymer rubber, only one type can be used alone, or two or more types can be used in any combination and ratio.

As the ethylene / α-olefin / non- conjugated diene copolymer rubber of the component (A), those synthesized using a Ziegler-based catalyst or a metallocene-based catalyst are preferably used. The Cheegler-based catalyst is a polymerization catalyst composed of a titanium compound, a vanadium compound and an organoaluminum compound, and the metallocene-based catalyst is a highly active polymerization composed of a cyclopentadienyl derivative of a transition metal such as titanium or zirconium and a co-catalyst. It is a catalyst.

The content of ethylene units in the ethylene / α-olefin / non- conjugated diene copolymer rubber is not particularly limited, but is preferably 50 to 90% by mass, more preferably 55 to 85% by mass, and further preferably 60. It is ~ 80% by mass. When the content of the ethylene unit is within the above preferable range, it tends to be easy to obtain a dynamically crosslinked thermoplastic elastomer composition having excellent mechanical strength and rubber elasticity.

The content of the α-olefin unit in the ethylene / α-olefin / non-conjugated diene copolymer rubber is not particularly limited, but is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, and further preferably. Is 20-40% by mass. When the content of the α-olefin unit is within the above preferable range, it tends to be easy to obtain a dynamically crosslinked thermoplastic elastomer composition having excellent mechanical strength, appropriate flexibility, and rubber elasticity.

Further, the content of the non-conjugated diene unit in the ethylene / α-olefin / non-conjugated diene copolymer rubber is not particularly limited, but is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass. Yes, more preferably 2-10% by mass. When the content of the non-conjugated diene unit is within the above preferable range, the crosslinkability and moldability can be easily adjusted, and a dynamically crosslinked thermoplastic elastomer composition having excellent mechanical strength and rubber elasticity tends to be easily obtained. It is in.

The content of each structural unit of the component (A) can be determined by infrared spectroscopy. In particular, the ethylene unit content is 55 to 75% by mass, the propylene unit content is 15 to 40% by mass, and it is selected from the group consisting of dicyclopentadiene, 5-ethylidene-2-norbornene, and vinylidene norbornene. An ethylene / propylene / non-conjugated diene copolymer rubber copolymer having a content of at least one non-conjugated diene of 1 to 10% by mass is preferable.

As a method for producing ethylene / propylene / non-conjugated diene copolymer rubber (EPDM), a known polymerization method using a known catalyst for olefin polymerization can be applied. For example, EPDM can be produced by a slurry polymerization method, a solution polymerization method, a massive polymerization method, a gas phase polymerization method or the like using a Ziegler-Natta catalyst, a complex catalyst such as a metallocene complex or a non-metallocene complex. .. In general, a solution polymerization method mainly using an aliphatic hydrocarbon as a solvent is adopted, and a slurry polymerization method using a monomer as a main solvent is also adopted in some cases. Further, a gas phase polymerization method in which various inert materials (for example, carbon black) are used as a dispersant in the monomer gas to promote the polymerization reaction has also been industrialized. Unlike the gas phase polymerization method, the synthesis by the solution polymerization method is excellent in suppressing bloom out because the polymer does not contain carbon black or the like. Further, when a metallocene catalyst is used, the effect of suppressing bloom-out is further improved. On the other hand, the synthesis by the vapor phase polymerization method can synthesize a polymer having a higher molecular weight than the solution polymerization method or the slurry polymerization method, and as a result, the Mooney viscosity can be increased, which is effective for oil resistance and compression set.

The weight average molecular weight in terms of polypropylene by the gel permeation chromatography method (GPC method) of the ethylene / α-olefin / non- conjugated diene copolymer rubber of the component (A) is not particularly limited, but is 100,000 or more. It is preferably more preferably 200,000 or more, further preferably 300,000 or more, preferably 1,000,000 or less, still more preferably 900,000 or less, still more preferably 800,000 or less. .. When the mass average molecular weight of the component (A) is within the above preferable range, the moldability, processability, and the like are improved, and the bleed-out of the hydrocarbon-based rubber softener tends to be easily suppressed.

In the present specification, the measurement conditions of the polypropylene-equivalent mass average molecular weight of the ethylene / α-olefin / non- conjugated diene copolymer rubber of the component (A) based on the GPC method are as follows.
Equipment: Waters 150C
Column: Shodex AD806MS x 3 (8.0 mm inner diameter x 300 mm length)
Detector: IR (dispersion type, 3.42 μm)
Solvent: ODCB
Temperature: 140 ° C
Flow rate: 1.0 mL / min Injection amount: 200 μL
Concentration: 10 mg / mL
Calibration sample: Polydisperse standard polyethylene Calibration method: Polypropylene conversion using Mark-Houwink formula

The density of the ethylene / α-olefin / non- conjugated diene copolymer rubber of the component (A) is not particularly limited, but is preferably 0.850 g / cm3 or more, and more preferably 0.860 g / cm3 or more. On the other hand, it is preferably 0.900 g / cm3 or less, and more preferably 0.890 g / cm3 or less. When the density of the ethylene / α-olefin / non- conjugated diene copolymer rubber of the component (A) is within the above-mentioned preferable number range, it is easy to obtain a thermoplastic elastomer composition having excellent processability, moldability, flexibility and the like. There is a tendency. The density can be measured based on JIS K7112: 1999.

An oil-extended ethylene / α-olefin / non- conjugated diene copolymer can also be used as the component (A). In the oil-extended ethylene / α-olefin / non- conjugated diene copolymer, the softening agent for hydrocarbon-based rubber softens the ethylene / α-olefin / non- conjugated diene copolymer rubber, and increases flexibility and elasticity. , It is used for the purpose of improving the processability and fluidity of the obtained thermoplastic elastomer composition.

Examples of the softener for hydrocarbon-based rubber include softeners for mineral oil-based rubber and softeners for rigid resin-based rubber. Among these, mineral oil-based softeners are used from the viewpoint of compatibility with other components. A softener for rubber is preferable. The softener for mineral oil-based rubber is generally a mixture of aromatic hydrocarbons, naphthenic hydrocarbons and paraffin-based hydrocarbons, and the ratio of carbon of the paraffin-based hydrocarbon to the total carbon atom is 50% by mass. The above are paraffin oils, those with a carbon content of naphthenic hydrocarbons of 30 to 45% are called naphthenic oils, and those with a carbon content of aromatic hydrocarbons of 35% or more are called aromatic oils. It has been. Among these, as the hydrocarbon-based rubber softener of the component (A), a paraffin-based rubber softener (paraffin-based oil) is preferable. As the softener for hydrocarbon rubber, only one type can be used alone, or two or more types can be used in any combination and ratio.

The paraffin-based oil of the component (A) is not particularly limited, but has a kinematic viscosity at 40 ° C. of usually 20 cst (centi-stokes) or more, preferably 50 cst or more, and usually 800 cst or less, preferably 600 cst or less. The pour point is usually −40 ° C. or higher, preferably −30 ° C. or higher, and 0 ° C. or lower is preferably used. The pour point is usually −40 ° C. or higher, preferably −30 ° C. or higher, and 0 ° C. or lower is preferably used. Further, a flash point (COC) of usually 200 ° C. or higher, preferably 250 ° C. or higher, and usually 400 ° C. or lower, preferably 350 ° C. or lower is preferably used.

Content ratio of ethylene / α-olefin / non-conjugated diene copolymer rubber and hydrocarbon softener when oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber is used as component (A) Is not particularly limited, but the content of the softening agent for hydrocarbon-based rubber is usually 10 parts by mass or more, preferably 20 parts by mass, based on 100 parts by mass of the ethylene / α-olefin / non-conjugated diene copolymer rubber. It is more than parts by mass, while it is usually 200 parts by mass or less, preferably 160 parts by mass or less, and more preferably 120 parts by mass or less.

When an oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber is used as the component (A), the method for preparing the oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber (oil spreading method) is , A known method can be used without particular limitation. As an oil spreading method, for example, a method of mechanically kneading an ethylene / α-olefin / non-conjugated diene copolymer and a softening agent for a hydrocarbon rubber by using a mixing roll or a Banbury mixer, and ethylene / A method in which a predetermined amount of a softening agent for hydrocarbon rubber is added to an α-olefin / non-conjugated diene copolymer and then desolvated by a method such as steam stripping, a crumb-shaped ethylene / α-olefin / non-conjugated diene Examples thereof include a method of impregnating a mixture of a copolymer and a hydrocarbon-based rubber softening agent by stirring with a Henshell mixer or the like. From the viewpoint of preparing a high molecular weight oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber, a polymerization reaction solution or suspension of the ethylene / α-olefin / non-conjugated diene copolymer rubber of the component (A). A method of adding a predetermined amount of a softening agent for hydrocarbon-based rubber to the liquid and then removing the polymer is preferable.

The Mooney viscosity (ML1 + 4, 120 ° C.) of the component (A) is not particularly limited, but is 50 to 150 or less, preferably 80 to 130. The Mooney viscosity of the component (A) is preferable from the viewpoint of improving the appearance of the thermoplastic elastomer when it is at least the above lower limit value, and is preferable from the viewpoint of moldability and low temperature impact resistance when it is at least the above upper limit value.

As the ethylene / α-olefin / non-conjugated diene copolymer rubber of the component (A), many grades of various grades are commercially available from domestic and overseas manufacturers, and the commercially available products can be used. Examples of commercially available products include JSR EPR manufactured by JSR, Mitsui EPT manufactured by Mitsui Chemicals, Esplen (registered trademark) manufactured by Sumitomo Chemical, and Keltan (registered trademark) manufactured by ARLANXEO.

[Component (B)]
The modified polypropylene of the component (B) is a polypropylene-based resin exhibiting strain curability. Here, "strain hardening" means a phenomenon in which the viscosity increases as the stretching strain of the melt increases, and the presence or absence of "strain hardening" in the present invention is determined when the melt tension is measured under the conditions described later. It can be determined from the breaking behavior of the molten strands of the above, and it is determined that the take-up load increases sharply when the take-up speed is increased, and that it exhibits strain curability when it reaches cutting.

The type of the modified polypropylene exhibiting the strain curability of the component (B) is not particularly limited, and may be either a propylene homopolymer, a block copolymer of propylene and another copolymer component, a random copolymer, or the like. Can also be used. As the component (B), only one type can be used alone, or two or more types can be used in any combination and ratio. Here, the propylene copolymer means that the content of the propylene unit is more than 50% by mass. From the viewpoint of heat resistance, rigidity, crystallinity, chemical resistance, etc., the content of the propylene unit in the propylene copolymer is preferably 60% by mass or more, more preferably 75% by mass or more, still more preferably 90% by mass. That is all. On the other hand, the upper limit is not particularly limited, but is usually less than 100% by mass. The content of the propylene unit in the component (B) can be determined by infrared spectroscopy.

When the modified polypropylene exhibiting the strain curability of the component (B) is a block copolymer or a propylene random copolymer, other copolymerization components that copolymerize with propylene include ethylene, 1-butene, and 1-butene. , 2-Methylpropylene, 1-Pentene, 3-Methyl-1-butene, 1-Hexen, 4-Methyl-1-Pentene, 1-octene, 1-decene and other α-olefins having 2 or 4 to 12 carbon atoms. Cyclic olefins such as cyclopentene, norbornene, tetracyclo [6,2,11,8,13,6] -4-dodecene; 5-methylene-2-norbornene, 5-ethylidene-2-norbornene, 1,4-hexadien, Dienes such as methyl-1,4-hexadien, 7-methyl-1,6-octadien; vinyl chloride, vinylidene chloride, acrylonitrile, vinyl acetate, acrylic acid, methacrylic acid, maleic acid, ethyl acrylate, butyl acrylate, methacryl Examples thereof include vinyl monomers such as methyl acid, maleic anhydride, styrene, methylstyrene, vinyltoluene and divinylbenzene, but the present invention is not particularly limited thereto. As these other copolymerization components, only one kind may be used alone, or two or more kinds may be used in any combination and ratio. Among these, ethylene and 1-butene are preferable. The content of each structural unit of the component (B) can be determined by infrared spectroscopy. Here, when the component (B) is a propylene block copolymer, a propylene block copolymer obtained by polymerizing in multiple steps is preferable. For example, a propylene block copolymer obtained by polymerizing polypropylene in the first step and polymerizing a propylene-ethylene copolymer in the second step is preferably used.

Further, as the component (B), a propylene (co) polymer having a branched structure, a propylene (co) polymer having a high molecular weight component, or the like is also preferably used. Examples of such a propylene (co) polymer include linear polypropylene such as a crystalline propylene homopolymer obtained by irradiating a linear polypropylene-based resin with radiation, a propylene homopolymer, a block copolymer, and a random copolymer. Examples thereof include a system resin, a conjugated diene compound, and a crystalline propylene (co) polymer obtained by melt-mixing a radical polymerization initiator. Among these, those having a branched structure are preferable.

The method for producing the modified polypropylene exhibiting the strain curability of the component (B) is not particularly limited, and for example, a known polymerization method using a known catalyst for olefin polymerization can be applied, and as an example thereof, a known polymerization method can be applied. A multi-stage polymerization method using a Ziegler-Natta catalyst can be mentioned. As this multi-stage polymerization method, a slurry polymerization method, a solution polymerization method, a bulk polymerization method, a gas phase polymerization method and the like can be used, and two or more of these may be combined for production.

The modified polypropylene showing the strain curability of the component (B) has a melt flow rate of 0.1 to 250 g / 10 minutes (MFR, 230 ° C., load 21.2 N, JIS) from the viewpoint of fluidity and moldability. (K7210 compliant) and polypropylene (co) polymers having a melt tension of 1.0 to 20 cN are preferably used.

The MFR of the modified polypropylene showing the strain curability of the component (B) is more preferably 0.3 g / 10 minutes or more, 100 g / 10 minutes or less, and further preferably 0.5 g / 10 minutes from the viewpoint of moldability and the like. It is 10 minutes or more and 70 g / 10 minutes or less. In particular, from the viewpoint of compression set, the MFR of the modified polypropylene exhibiting the strain curability of the component (B) is particularly preferably 50 g / 10 minutes or less, still more preferably 30 g / 10 minutes or less, and most preferably 10 g / min. It is less than 10 minutes. The MFR of the modified polypropylene showing the strain curability of the component (B) is based on JIS K7210, and means a value measured at 230 ° C. and a load of 2.12 N.

The melt tension of the modified polypropylene showing the strain curability of the component (B) is more preferably 1.5 to 19 cN, still more preferably 2.0 to 18 cN from the viewpoint of moldability, compression set, and the like. , Particularly preferably 2.5 to 15 cN. Here, the melt tension is 200 ° C. using a capillograph (manufactured by Toyo Seiki Seisakusho) equipped with an attachment for measuring melt tension and having a φ10 mm cylinder equipped with an orifice of φ1 mm and a length of 10 mm at the tip. The strands discharged from the die when lowered at a piston descent speed of 10 mm / min are hung on a pulley with a load cell 350 mm below and picked up at a speed of 1 m / min. The load applied to the pulley with a load cell when the strand breaks is measured, and this measured load is used as the melt tension.

As the modified polypropylene showing the strain curability of the component (B), many grades of various grades are commercially available from domestic and overseas manufacturers, and the commercially available products can be used. Examples of commercially available products include Prime Polypro (registered trademark) of Prime Polymer Co., Ltd., Sumitomo Noblen (registered trademark) of Sumitomo Chemical Co., Ltd., polypropylene block copolymer of Sun Aroma Co., Ltd., Novatec (registered trademark) PP of Japan Polypropylene Corporation, and Waymax (registered trademark). Registered trademark), Moldell (registered trademark) of Lyondell Basell, ExxonMobile PP of ExxonMobile, Forumorene (registered trademark) of Polymera Plastics, Borealis PP of Borealis, SEETEC PP of LG Chemical. Schulman's ASI POLYPROPYLENE, INEOS Olefins & Polymers, Inc. of INEOS PP, Braskem's Braskem PP, SAMSUNG TOTAL PETROCHEMICALS's Sumsung Total, Sabic's Sabic (registered trademark) PP, TOTAL PETROCHEMICALS company of TOTAL PETROCHEMICALS Polypropylene, SK Corporation of YUPLENE ( Registered trademark) and the like.

[Component (C)]
The cross-linking agent of the component (C) partially cross-links the above-mentioned component (A) in the resin composition containing each component in the dynamic heat treatment, whereby the dynamically cross-linked elastomer composition can be obtained. It will be realized. The cross-linking agent can be appropriately selected from known ones and used, and is not particularly limited, but organic peroxides and phenol resins are preferably used. As the cross-linking agent, only one type can be used alone, or two or more types can be used in any combination and ratio.

Examples of the organic peroxide of the component (C) include aromatic organic peroxides and aliphatic organic peroxides. Specifically, di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl. -2,5-di (t-butylperoxy) hexin-3,1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-di (t-butylperoxy) -3,3,5 -Dialkyl peroxides such as trimethylcyclohexane; t-butylperoxybenzoate, t-butylperoxyisopropylcarbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2 , 5-Di (benzoylperoxy) Peroxyesters such as hex-3; Hydroper such as acetyl peroxide, lauroyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, etc. Examples thereof include oxides, but the present invention is not particularly limited thereto. Among these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane is preferable.

As the phenol resin of the component (C), a non-halogen phenol resin is preferably used. Examples of the non-halogen-based phenol resin include an alkyl-substituted phenol or a condensate of an unsubstituted phenol and an aldehyde in an alkaline medium, preferably a condensate of formaldehyde, which does not contain a halogen atom. The substituted alkyl group in the alkyl-substituted phenol preferably has less than 20 carbon atoms, and more preferably dimethylolphenols substituted with a substituted alkyl group having 1 to 12 carbon atoms at the p-position. Further, as a non-halogen-based phenol resin, a condensate of bifunctional phenol dialcohols is also preferably used. It should be noted that US Pat. No. 4,311,628, US Pat. No. 2,972,600 and 3,287,440 disclose cross-linking techniques for thermoplastic vulcanized rubber using a phenol resin. Technology can also be applied.

（式中、Ｑは、－二価の連結基－ＣＨ₂ －、又は－ＣＨ₂ －Ｏ－ＣＨ₂ －から選択され、ｎは０又は１～２０であり、Ｒは炭素数２０未満、好ましくは炭素数１～１２の有機基である。） More specifically, as the phenol resin of the component (C), those represented by the following general formula (I) are preferable.

(In the formula, Q is selected from the -divalent linking group -CH _2- or -CH ₂ -O-CH _2- , n is 0 or 1 to 20, and R is preferably less than 20 carbon atoms. Is an organic group having 1 to 12 carbon atoms.)

Examples of the above non-halogen phenolic resin products include Tackylol 201 and 202 (trade name) manufactured by Taoka Chemical Industry Co., Ltd., PR-4507 (trade name) manufactured by Gunei Chemical Industry Co., Ltd., and Hoechst Co., Ltd. Vulkarest 510E, 532E, Vulkaresen E, 105E, 130E, Vulkaresol 315E (trade name), Amberol ST 137X (trade name) manufactured by Rohm & Haas, Sumilite Resin PR-22193 (trade name) manufactured by Sumitomo Durez Co., Ltd. Anchor Chem. Symphon-C-100, C-1001 (trade name) manufactured by Arakawa Chemical Industry Co., Ltd., Tamanol 531 (trade name) manufactured by Arakawa Chemical Industry Co., Ltd., Schenectady Chem. Schenectady SP1045, SP1055, SP1056, SP1059 (trade name) manufactured by Schenectady, U.S.A. C. Examples include CRR-0803 (trade name) manufactured by C company, CRM-0803 (trade name) manufactured by Showa Union Synthetic Co., Ltd., Vulkadur A (trade name) manufactured by Bayer, and the like.

In particular, as the non-halogen phenol resin of the component (C), the p-octylphenol formaldehyde resin represented by the following formula is particularly preferably used, and among them, the one having a mass average molecular weight Mw of 2,500 to 4,000 is the most. It is preferably used. As the non-halogen-based phenolic resin, those commercially available as the above-mentioned Tuckillol 201, 202 (trade name) can be used.

Further, in addition to the above-mentioned organic peroxide and phenol resin, other cross-linking agents may be used, for example, sulfur, p-quinonedioxime, p-dinitrosobenzene, 1,3-diphenylguanidine and the like. Auxiliary agent for peroxides; Polyfunctional vinyl compounds such as divinylbenzene, triallyl cyanurate, trimethylolisocyanurate, diallyl phthalate; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) Polyfunctional (meth) acrylate compounds such as acrylates, trimethylolpropane tri (meth) acrylates and allyl (meth) acrylates; Compounds having a bismaleimide structure; trimethylolpropane, trimethylolpropane trimethacrylate, tin chloride (SnCl ₂ ) and the like can be mentioned. These may be used alone or in combination of two or more. As the cross-linking agent, only one type can be used alone, or two or more types can be used in any combination and ratio.

[Component (D): Hydrocarbon-based rubber softener]
The dynamically crosslinked thermoplastic elastomer composition of the present embodiment contains a hydrocarbon-based rubber softener as a component (D) from the viewpoint of increasing flexibility and elasticity and improving processability and fluidity. Is preferable. This component (D) is a softening agent for hydrocarbon-based rubber contained therein when oil-extended ethylene / α-olefin / non- conjugated diene copolymer rubber is used as the above-mentioned component (A). , A softening agent for hydrocarbon-based rubber attached. As this component (D), any of the same, the same type, and different types of hydrocarbon-based rubber softeners as those in the above-mentioned component (A) can be used.

Examples of the softening agent for hydrocarbon-based rubber of the component (D) include a softening agent for mineral oil-based rubber and a softening agent for rigid resin-based rubber. Among these, from the viewpoint of compatibility with other components and the like. Therefore, a softening agent for mineral oil-based rubber is preferable. The softener for mineral oil-based rubber is generally a mixture of aromatic hydrocarbons, naphthenic hydrocarbons and paraffin-based hydrocarbons, and the ratio of carbon of the paraffin-based hydrocarbon to the total carbon atom is 50% by mass. The above are paraffin oils, those with a carbon content of naphthenic hydrocarbons of 30 to 45% are called naphthenic oils, and those with a carbon content of aromatic hydrocarbons of 35% or more are called aromatic oils. It has been. Among these, as the softening agent for hydrocarbon rubber of the component (D), a liquid hydrocarbon softener which is liquid at room temperature (23 ± 2 ° C.) is preferable, and a liquid paraffin oil which is liquid at room temperature is preferable. Is more preferable. By using the softening agent for liquid hydrocarbon-based rubber as the softening agent for hydrocarbon-based rubber of the component (D), the flexibility and elasticity of the dynamically crosslinked thermoplastic elastomer composition of the present embodiment can be increased. In addition, workability and fluidity tend to improve dramatically. As the hydrocarbon-based rubber softener of the component (D), only one type can be used alone, or two or more types can be used in any combination and ratio. When oil-extended ethylene / α-olefin / non- conjugated diene copolymer rubber is used as the component (A), a softening agent for hydrocarbon-based rubber can be attached to the softening agent for hydrocarbon-based rubber. The content ratio can be arbitrarily adjusted without depending on the content ratio of the softening agent for hydrocarbon-based rubber in the oil-developed ethylene / α-olefin / non- conjugated diene copolymer rubber.

The paraffin-based oil of the component (D) is not particularly limited, but has a kinematic viscosity at 40 ° C. of usually 20 cst (centistokes) or more, preferably 50 cSt or more, and usually 800 cSt or less, preferably 600 cSt or less. The pour point is usually −40 ° C. or higher, preferably −30 ° C. or higher, and 0 ° C. or lower is preferably used. The pour point is usually −40 ° C. or higher, preferably −30 ° C. or higher, and 0 ° C. or lower is preferably used. Further, a flash point (COC) of usually 200 ° C. or higher, preferably 250 ° C. or higher, and usually 400 ° C. or lower, preferably 350 ° C. or lower is preferably used.

[Mixing ratio]
In the dynamically crosslinked thermoplastic elastomer composition of the present embodiment, the composition ratio of each of the above components (A) to (D) is not particularly limited, but the mechanical strength and the compression set are enhanced, and the flexibility and molding processability are enhanced. From the viewpoint of improving the above, the content ratio of the components (A) and (B) in terms of solid content is preferably 40% by mass or more and less than 95% by mass in total, and more preferably 50% by mass or more in total. It is 85% by mass or less.

The blending ratios of the components (A) and (B) are not particularly limited, but the components (A) and the components (A) and the components (A) and the components (A) and the components (B) can be improved from the viewpoints of increasing mechanical strength and compression set, as well as improving flexibility and moldability. The component (A) is preferably 50 to 90 parts by mass, the component (B) is preferably 10 to 50 parts by mass, and more preferably the component (A) is 60 to 89 parts by mass with respect to a total of 100 parts by mass of (B). Parts, the component (B) is 11 to 40 parts by mass, more preferably the component (A) is 65 to 88 parts by mass, and the component (B) is 12 to 35 parts by mass.

On the other hand, the blending ratio of the component (C) is not particularly limited, but the total amount of the dynamically crosslinked thermoplastic elastomer composition is adjusted from the viewpoint of sufficiently advancing the crosslinking reaction to increase the mechanical strength and the compression set. On the other hand, it is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.3% by mass or more. On the other hand, from the viewpoint of controlling an excessive crosslinking reaction, it is preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less.

The blending ratio of the component (D) is not particularly limited, but the total of the components (A) and (B) is 100 from the viewpoint of flexibility, elasticity, processability, fluidity, etc. of the obtained thermoplastic elastomer composition. It is preferably 10 to 200 parts by mass, more preferably 25 to 150 parts by mass, and further preferably 40 to 100 parts by mass with respect to the mass part.

In addition to the above-mentioned components (A) to (D), the dynamically crosslinked thermoplastic elastomer composition of the present embodiment may contain other resin components and other resin components depending on the intended purpose, as long as the effects of the present invention are not excessively impaired. It may contain various additives. Examples of the other resin components include polypropylene-based resins other than the above-mentioned components (A) and (B) (hereinafter, may be simply referred to as “component (E)”), and resins other than these (hereinafter, simply “others”). It may be referred to as "resin") and the like. As for other resin components and various additives, only one type can be used alone, or two or more types can be used in any combination and in any ratio.

[Ingredient (E)]
Specific examples of the polypropylene-based resin of the component (E) include a propylene homopolymer, a random or block copolymer of propylene and α-olefin, and the like. Here, the propylene-based copolymer means a polymer containing propylene in a composition of 50 mol% or more of a monomer unit. Examples of α-olefins include ethylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 1-hexene and 4-methyl-. Examples thereof include α-olefins having 3 to 20 carbon atoms, more preferably 3 to 8 carbon atoms such as 1-hexene, 1-hexene, 1-octene, 1-decene and 1-octadecene, but the present invention is not particularly limited thereto. As the α-olefin, only one type can be used alone, or two or more types can be used in any combination and ratio.

Among these, a propylene homopolymer and a propylene / ethylene random copolymer are preferable because they can be easily obtained at low cost and are excellent in economy. From the viewpoint of mechanical properties, a propylene homopolymer and a propylene / ethylene random copolymer are more preferable. As the polypropylene-based resin, only one type can be used alone, or two or more types can be used in any combination and ratio.

The density of the polypropylene-based resin of the component (E) is not particularly limited, but is preferably 0.85 g / cm ³ or more, more preferably 0.87 g / cm ³ or more, while 0.96 g / cm ³ or less. It is preferable, more preferably 0.95 g / cm ³ or less. Here, the density of the polypropylene-based resin of the component (E) means a value measured according to JIS K7112: 1999.

The melt flow rate of the polypropylene-based resin of the component (E) is not particularly limited, but is preferably 0.01 to 50 g / 10 minutes, more preferably 0.1 to 10 g / 10 minutes from the viewpoint of moldability and the like. Is. Here, the MFR of the polypropylene-based resin of the component (E) means a value measured at 230 ° C. and a load of 2.12 N in accordance with JIS K7210.

The melt tension of the polypropylene-based resin of the component (E) is not particularly limited, but is preferably 0.05 to 5 cN, more preferably 0.1 to 4 cN, and even more preferably 0.1 to 4 cN from the viewpoint of moldability, compression set, and the like. Is 0.2 to 2.5 cN, and particularly preferably 0.3 to 2.0 cN. The melt tension is measured under the same conditions as the above-mentioned component (B).

When the dynamically crosslinked thermoplastic elastomer composition of the present embodiment contains the polypropylene-based resin of the component (E), it is not particularly limited, but it enhances mechanical strength and compression set, and improves flexibility and moldability. From the viewpoint of improvement and the like, the total content ratio of the components (A), (B), and (E) in terms of solid content is preferably 40% by mass or more and less than 95% by mass, and more preferably the total. It is 50% by mass or more and 85% by mass or less.

The mixing ratio of the polypropylene-based resin of the component (E) is not particularly limited, but is preferably 5 to 50 parts by mass with respect to a total of 100 parts by mass of the components (A), (B), and (E). It is preferably 7 to 40 parts by mass, more preferably 10 to 35 parts by mass.

Further, the content ratio of the components (B) and (E) in the dynamically crosslinked thermoplastic elastomer composition of the present embodiment in terms of solid content is not particularly limited, but is preferably 99: 1 to 1:99. It is preferably 90:10 to 30:70, and more preferably 80:20 to 40:60.

[Other resins]
The type of other resin is not particularly limited as long as it is other than the above-mentioned components (A) to (B) and (E). Ethylene (co) copolymers such as high density polyethylene (HDPE), low density polyethylene (LDPE), ultra low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), polyethylene-based (co) polymers and polypropylene-based Polyethylene-based copolymers other than copolymers, polyester-based (co) polymers such as polyethylene terephthalate and polybutylene terephthalate, polyamide-based (co) polymers such as nylon 66 and nylon 11, and styrene-based (co) such as polystyrene. Polymers, (meth) acrylic (co) polymers such as polymethylmethacrylate resins, polyphenylene ether (co) polymers, polyoxymethylene homopolymers, polyoxymethylene copolymers and other polyoxymethylene (co) weights Combined, polycarbonate-based (co) polymer, polyvinyl chloride-based (co) polymer, ethylene-butene copolymer rubber (EBM), olefin-based thermoplastic elastomer such as ethylene / propylene / butene copolymer rubber, styrene-based thermoplastic Examples thereof include an elastomer, a polyester-based thermoplastic elastomer, and a urethane-based thermoplastic elastomer, but the present invention is not particularly limited thereto. One of these resins can be used alone, or two or more of these resins can be used in any combination. When the dynamically crosslinked thermoplastic elastomer composition of the present embodiment contains other resins, it is not particularly limited, but 1 to 1 to the total amount of the above-mentioned components (A) to (B) and (E). It is preferably 100% by mass, more preferably 2 to 50% by mass, and even more preferably 3 to 10% by mass.

[Various additives]
Various additives include additives known in the art, such as process oils, processing aids, plasticizers, crystal nucleating agents, impact improvers, flame retardants, flame retardants, cross-linking aids, antistatic agents, etc. Conductivity-imparting agents, metal inactivating agents, lubricants, fillers, compatibilizers, dispersants, neutralizers, heat stabilizers, weather stabilizers (antioxidants, light stabilizers, UV absorbers, etc.), carbon Examples thereof include black, colorants (pigments, dyes, etc.), antibacterial agents, antifungal materials, fluorescent whitening agents, and the like, but the present invention is not particularly limited thereto. When these additives are used, the content thereof is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0., With respect to the total amount of the dynamically crosslinked thermoplastic elastomer composition of the present embodiment. It is 2% by mass or more, preferably 5% by mass or less, and more preferably 2% by mass or less.

Flame retardants are roughly classified into halogen-based flame retardants and non-halogen flame retardants. Among these, non-halogen flame retardants are preferable. Specific examples thereof include metal hydroxides, phosphorus-based flame retardants, nitrogen-containing compounds (melamine-based and guanidine-based) flame retardants and inorganic compounds (borate and molybdenum compounds) flame retardants. Examples of the heat stabilizer and antioxidant include hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, halides of alkali metals and the like. Specific examples of the antioxidant include a phenol-based antioxidant, a sulfide-based antioxidant, a thioether-based antioxidant, and the like.

Fillers are roughly classified into organic fillers and inorganic fillers. Examples of the organic filler include naturally derived polymers such as starch, cellulose fine particles, wood flour, okara, fir husks, and bran, and modified products thereof. Examples of the inorganic filler include talc, calcium carbonate, zinc carbonate, wallastonite, silica, alumina, mica, potassium titanate fiber, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, and sodium aluminate. Magnesium silicate, metal soap, titanium dioxide, glass fiber, hollow glass ball, glass balloon, carbon black, zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate, boron nitride , Carbon black, graphite, carbon fiber and the like.

[Manufacturing method of thermoplastic elastomer composition]
The dynamically crosslinked thermoplastic elastomer composition of the present embodiment includes the above-mentioned components (A), (B), (C) and (D), and if necessary, the component (E) and further. Other resin components and various additives are manufactured by mixing, kneading or melt-kneading by a conventional method using an ordinary extruder, Banbury mixer, mixing roll, roll, brabender plastograph, kneader brabender, etc. be able to. Among these, it is preferable to use an extruder, particularly a twin-screw extruder. When the dynamically crosslinked thermoplastic elastomer composition of the present embodiment is kneaded and produced by an extruder or the like, it is preferably melt-kneaded in a state of being heated to usually 80 to 300 ° C, preferably 100 to 250 ° C. .. The treatment time for performing the dynamic heat treatment is not particularly limited, but is usually 0.1 to 30 minutes in consideration of productivity and the like.

Here, "dynamic heat treatment" means kneading in a molten state or a semi-melted state in the presence of the component (C). This dynamic heat treatment is preferably performed by melt-kneading, and when a twin-screw extruder is used, each component is supplied to a raw material supply port (hopper) of a twin-screw extruder having a plurality of raw material supply ports. It is more preferable to perform a heat treatment. By performing the dynamic heat treatment of melting and kneading in the presence of the above component (C) in this way, a dynamically crosslinked thermoplastic elastomer composition can be obtained.

When performing dynamic heat treatment with a twin-screw extruder, the barrel radius R (mm), screw rotation speed N (rpm), and discharge amount Q (kg / hour) of the twin-screw extruder are as follows from the viewpoint of productivity and the like. It is preferable to melt-extrude while maintaining the relationship of the formula.
2.6 <(N × Q) / R ³ <22.6

Further, it is preferable to extrude while maintaining the relationship of the following formula.
3.0 <(N × Q) / R ³ <20.0

[Various physical characteristics]
The melt flow rate (based on MFR, JIS K7210, temperature 230 ° C., load 49N) of the dynamically crosslinked thermoplastic elastomer composition of the present embodiment is not particularly limited, but is 0 from the viewpoint of handleability, moldability, and the like. .5 to 20 g / 10 minutes, more preferably 0.6 g / 10 minutes or more, 14 g / 10 minutes or less, still more preferably 0.8 g / 10 minutes or more, 10 g / 10 minutes or less, particularly preferably. 0.8 g / 10 minutes or more and 8 g / 10 minutes or less.

The density of the dynamically crosslinked thermoplastic elastomer composition of the present embodiment is not particularly limited, but is preferably 0.850 g / cm ³ or more, more preferably 0.860 g / cm ³ or more, on the other hand. It is preferably 1,000 g / cm ³ or less, and more preferably 0.950 g / cm ³ or less. The density can be measured based on JIS K7112: 1999.

The dynamically crosslinked thermoplastic elastomer composition of the present embodiment has excellent rubber elasticity without impairing mechanical strength. In the present specification, the value of the tear strength at cutting (JIS K6251 compliant, test speed: 500 mm / min) measured by the method shown in the examples described later is used as an index of mechanical strength. The mechanical strength is preferably 5.0 MPa or more, more preferably 5.5 MPa or more, still more preferably 6.0 MPa or less at room temperature 23 ± 2 ° C.

The value of the hardness Duro A (based on JIS K6253 (JIS-A), hardness after 15 seconds) of the dynamically crosslinked thermoplastic elastomer composition of the present embodiment is not particularly limited, but is preferably 60 to 90, more preferably. Is 65-85. The method for measuring the hardness Duro A is shown in Examples described later.

The value of the permanent compression strain (70 ° C. × 22 hours) of the dynamically crosslinked thermoplastic elastomer composition of the present embodiment is not particularly limited, but is preferably 50% or less, more preferably 45% or less, still more preferably 43. % Or less. The method for measuring the permanent compression strain is shown in Examples described later.

[Molded body / use]
The dynamically crosslinked thermoplastic elastomer composition of the present embodiment is a molding method used for a normal thermoplastic elastomer composition, for example, an injection molding method such as a gas injection molding method, an injection compression molding method, a short shot foam molding method, or the like. A molded product can be formed by using various molding methods such as an extrusion molding method, a hollow molding method, and a compression molding method. Among these, the injection molding method and the extrusion molding method are preferable. For example, in the case of injection molding, the molding temperature is generally 150 to 300 ° C, preferably 180 to 280 ° C. The injection pressure is usually 5 to 100 MPa, preferably 10 to 80 MPa. On the other hand, the mold temperature is usually 0 to 80 ° C, preferably 20 to 60 ° C. After performing these moldings, it is also possible to further perform secondary processing such as laminating molding or thermoforming on the obtained molded body.

Since the dynamically crosslinked thermoplastic elastomer composition of the present embodiment exerts the above-mentioned effect, it is suitable as a member for automobiles and a member for building materials, particularly as a sealing material for automobiles and a sealing material for building materials. Further, the dynamically crosslinked thermoplastic elastomer composition of the present embodiment includes automobile parts (airbag storage cover, center panel, center console box, door trim, pillar, assist grip, etc.) other than the sealing material for automobiles and the sealing material for building materials. Steering, weather strips, ceiling materials, interior seats, bumper moldings, side moldings, air spoilers, air duct hoses, sealing materials, various packings, etc.), civil engineering / building material parts (water blocking materials, joint materials, window frames, window frame packings, etc.) , Sealing materials, etc.), Sporting goods (grips for golf clubs and tennis rackets, etc.), Industrial parts (hose tubes, gaskets, etc.), Home appliances parts (hoses, packings, etc.), Medical parts (medical containers, gaskets, etc.) , Packing, etc.), food parts (containers, packings, etc.), medical equipment parts, electric wires, miscellaneous goods, etc., and is particularly suitable as a molding material for automobile interior parts.

Hereinafter, the content of the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. The values of various production conditions and evaluation results in the following examples have meanings as preferable values of the upper limit or the lower limit in the embodiment of the present invention, and the preferable range is the preferable value of the upper limit or the lower limit described above. The preferred range may be a range defined by a combination of the above-mentioned upper limit or lower limit value and the value of the following examples or the values of the examples.

<Raw materials>
The raw materials used in the following Examples / Comparative Examples are as follows.

[Ingredient (A)]
(A-1): Ethylene / α-olefin / non- conjugated diene copolymer rubber (ethylene / propylene / ethylidene norbornen ternary copolymer rubber, manufactured by Mitsui Chemicals Co., Ltd., trade name: EPT3092PM, non-oil exhibition type, Mooney Viscosity (ML1 + 4, 125 ° C.): 61, ethylene content: 65% by mass, ethylidene norbornene content: 4.6% by mass)

[Component (B)]
(B-1): Modified polypropylene exhibiting strain curability (manufactured by Kaneka Corporation, product number: 049N, MFR: 1.0 g / 10 minutes (230 ° C., load 21.2N, JIS K7210 compliant), melt tension: 9.2cN)
(B-2): Modified polypropylene exhibiting strain curability (manufactured by Kaneka Corporation, product number: KIS-51, MFR: 0.5 g / 10 minutes (230 ° C, load 21.2 N, JIS K7210 compliant), melt Tension: 11.1cN)
(B-3): Modified polypropylene exhibiting strain curability (manufactured by Japan Polypropylene Corporation, product number: WAYMAX MFX8, MFR: 1.0 g / 10 minutes (230 ° C., load 21.2 N, JIS K7210 compliant), melt Tension: 11.7cN)

[Component (C)]
(C-1): 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (manufactured by Kayaku Akzo Corporation, trade name: Kayahexa AD40C, 2,5-dimethyl-2,5-di) (T-Butylperoxy) Mixture of 40% by mass of hexane and 60% by mass of calcium carbonate)
(C-2): Divinylbenzene (manufactured by Wako Pure Chemical Industries, Ltd., a mixture of divinylbenzene, 55% by mass of divinylbenzene and 45% by mass of ethylvinylbenzene)

[Component (D)]
(D-1): Paraffin-based rubber softener (paraffin-based oil manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana (registered trademark) process oil PW90, kinematic viscosity at 40 ° C.: 95.54 cSt (centistokes), flow Point: -15 ° C, ignition point: 272 ° C)

[Ingredient (E)]
(E-1): Polypropylene resin (manufactured by Japan Polypropylene Corporation, polypropylene homopolymer, trade name: Novatec (registered trademark) PP FY6, MFR: 2.5 g / 10 minutes (230 ° C, load 21.2 N, JIS) K7210 compliant), density: 0.90 g / cm ³ (JIS K7112: 1999), melt tension: 0.9 cN)

<Evaluation method>
Various evaluation methods of the thermoplastic elastomer composition in Examples and Comparative Examples are shown below. In the measurements (2) to (4) below, an in-line screw type injection molding machine (manufactured by Toshiba Machine Co., Ltd., product number: IS130) was used, and the injection pressure was 50 MPa, the cylinder temperature was 220 ° C, and the mold temperature was 40 ° C. Under the above conditions, each thermoplastic elastomer composition was injection-molded to form a sheet having a thickness of 2 mm, a width of 120 mm, and a length of 80 mm. Further, in the tensile test of (3) below, the obtained sheet (thickness 2 mm × width 120 mm × length 80 mm) was obtained by using a test piece punching blade (JIS No. 3 type dumbbell shape) in accordance with JIS K6251. ) Was punched out from a dumbbell-shaped test piece, and measurement was performed using this test piece. On the other hand, in the compression set of the following (4), the Type A disk obtained by punching out the obtained sheet (thickness 2 mm × width 120 mm × length 80 mm) in accordance with JIS K6262: 6 sheets of Type A disk: 29 mmφ were stacked and tested. Pieces were made and measured using this test piece.

(1) Melt flow rate (MFR)
It was measured at 230 ° C. and a load of 49 N according to JIS K7210.

(2) Hardness Duro A
The hardness (after 15 seconds) was measured according to JIS K6253 (JIS-A).

(3) Tensile strength during cutting / Elongation during cutting (tensile test)
According to JIS K6251, the test speed was measured at 500 mm / min.

(4) Permanent compression strain Measured at 70 ° C. for 22 hours under 25% compression conditions in accordance with JIS K6262 standards.

[Example 1]
Ingredient (A-1) 45% by mass, Ingredient (B-1) 20% by mass, Ingredient (C-1) 0.4% by mass, Ingredient (C-2) 0.3% by mass, Antioxidant (BASF Japan) Made by Co., Ltd., trade name: Irganox (registered trademark) 1010) 0.1 parts by mass, filler (calcium carbonate) 1.5 parts by mass, and black pigment (carbon concentration 40% by mass) 2 parts by mass. , Was mixed with a Henschel mixer for 1 minute. Next, the obtained mixture is charged into the upstream supply port of the same-direction twin-screw extruder (manufactured by Japan Steel Works, Ltd., product number: TEX30, L / D = 46, number of cylinder blocks: 12) by a mass feeder. bottom. Then, 35% by mass of the component (D-1) is supplied from the supply port in the middle of the extruder by the liquid addition pump, and the total discharge amount is 20 kg / h, and the range from the upstream portion to the downstream portion is in the range of 120 to 180 ° C. The temperature was raised in 1 and the mixture was melt-kneaded and pelletized to produce the dynamically crosslinked thermoplastic elastomer composition of Example 1. Table 1 shows various physical properties of the obtained dynamically crosslinked thermoplastic elastomer composition of Example 1.

[Examples 2 to 5 and Comparative Examples 1 to 2]
The same treatment as in Example 1 was carried out except that the composition was changed to the composition shown in Table 1, and the pellets of the dynamically crosslinked thermoplastic elastomer compositions of Examples 2 to 5 and Comparative Example 1 and the heat of Comparative Example 2 were obtained. Pellets of the thermoplastic elastomer composition were obtained respectively. Table 1 shows the various physical characteristics of each.

[Evaluation results]
As shown in Table 1, it can be seen that all of Examples 1 to 5 corresponding to the dynamically crosslinked thermoplastic elastomer composition of the present invention have good mechanical strength and compressive permanent strain characteristics. On the other hand, the dynamically crosslinked thermoplastic elastomer composition of Comparative Example 1 containing no component (B) had insufficient compressive permanent strain characteristics. Further, the olefin-based thermoplastic elastomer composition of Comparative Example 2 which was not dynamically crosslinked had extremely poor compressive permanent strain characteristics and was also inferior in mechanical strength.

Since the thermoplastic elastomer composition of the present invention is excellent in mechanical strength and compression set, various applications for which these are required, such as automobile parts, civil engineering / building material parts, sporting goods, industrial parts, home appliance parts, medical treatment, etc. It can be widely and effectively used in parts for automobiles, food parts, medical equipment parts, electric wires, miscellaneous goods, etc., and is particularly effective as a sealant for automobile interior parts and building materials, especially a sealant for automobiles and a sealant for building materials. It is available.

Claims (10)

In addition to containing the following components (A), component (B), component (C) , component (D) , and component (E) ,
The component (A) is contained in an amount of 50 to 90 parts by mass and the component (B) is contained in an amount of 10 to 50 parts by mass with respect to a total of 100 parts by mass of the components (A) and (B).
A dynamically crosslinked thermoplastic elastomer composition in which the blending ratio of the component (E) is 0 to 50 parts by mass with respect to a total of 100 parts by mass of the components (A), (B), and (E) .
Component (A): Ethylene / α-olefin / non- conjugated diene copolymer rubber Component (B): Modified polypropylene exhibiting strain curability Component (C): Cross-linking agent Component (D): Hydrocarbon-based rubber softener
Component (E): Polypropylene resin The dynamically crosslinked thermoplastic elastomer composition according to claim 1 , wherein the content ratio of the components (B) and (E) in terms of solid content is 99: 1 to 1:99. The dynamically crosslinked thermoplastic elastomer composition according to claim 1 or 2 , wherein the value of hardness Duro A (JIS K6253 (JIS-A) compliant, hardness after 15 seconds) is 60 to 90. Claim 1 to claim 1, wherein the component (B) has a melt flow rate of 0.1 to 250 g / 10 minutes (MFR, 230 ° C., load 21.2 N, JIS K7210 compliant) and a melt tension of 1.0 to 20 cN. 3. The dynamically crosslinked thermoplastic elastomer composition according to any one of 3. Any of claims 1 to 4 , wherein the component (C) comprises at least one selected from the group consisting of an organic peroxide, a phenol resin, a polyfunctional vinyl compound, a polyfunctional (meth) acrylate compound, and tin chloride. The dynamically crosslinked thermoplastic elastomer composition according to item 1. The dynamically crosslinked thermoplastic elastomer composition according to any one of claims 1 to 5 , wherein the content ratio of the component (C) is 0.05 to 20% by mass. The dynamic crosslinking according to any one of claims 1 to 6 , wherein the content ratio of the component (D) is 10 to 200 parts by mass with respect to a total of 100 parts by mass of the components (A) and (B). Molded thermoplastic elastomer composition. The dynamically crosslinked thermoplastic elastomer composition according to any one of claims 1 to 7 is molded.
Molded body. The dynamically crosslinked thermoplastic elastomer composition according to any one of claims 1 to 7 is molded.
Automotive parts. The dynamically crosslinked thermoplastic elastomer composition according to any one of claims 1 to 7 is molded.
Materials for building materials.