JP2019044111A - Dynamic crosslinking type thermoplastic elastomer composition and molded body thereof - Google Patents

Abstract

To provide a novel dynamic crosslinking type thermoplastic elastomer composition excellent in low hardness and permanent compression set, and good in appearance when made a molded body.SOLUTION: There is provided a dynamic crosslinking type thermoplastic elastomer composition containing following components (A) to (D) and having Duro A hardness in JIS K6253 of 60 or less. Content of the component (A) is 70 to 90 pts.mass, content of the component (B) is 10 to 30 pts.mass in total 100 pts.mass of the component (A) and the component (B). content of the component (C) is 0.05 to 20 pts.mass and content of the component (D) is 20 to 200 pts.mass based on total 100 pts.mass of the component (A) and the component (B). Component (A): an ethylene α-olefin non-conjugated diene copolymer rubber component. Component (B): modified polypropylene having melt flow rate of 0.1 to 250 g/10 min. and melt tension of 1.0 to 20 cN, and exhibiting strain hardening property. Component (C): a crosslinking agent. Component (D): a softener for hydrocarbon rubber.SELECTED DRAWING: None

Description

  The present invention relates to a dynamically crosslinked thermoplastic elastomer composition and a molded article thereof. More specifically, the present invention relates to a novel dynamically crosslinked thermoplastic elastomer composition having low hardness and excellent in molding appearance and compression set, and a molded article using the same.

  In the past, extrusion-vulcanized molded articles made of rubber blends of ethylene / propylene / non-conjugated diene terpolymer (EPDM) required for low hardness and rubber elasticity in automobile parts, electric / electronic parts, construction parts etc. Were generally used in the However, in recent years, thermoplastic elastomer compositions which do not require a vulcanization process have begun to be used in these fields from the viewpoint of productivity, environmental responsiveness and weight reduction.

  For example, a mixture of a polyolefin-based resin such as polypropylene and polyethylene which imparts thermoplasticity, an ethylene / propylene / non-conjugated diene copolymer rubber which imparts rubber elasticity, and a mixture of a softener which imparts flexibility and flowability are crosslinked. Thermoplastic elastomer composition obtained by dynamic heat treatment in the presence of a curing agent exhibits the characteristics as a rubber-like soft material even though the vulcanization step is unnecessary, and the same moldability as a thermoplastic resin is obtained It is known to have. Such a thermoplastic elastomer composition is called a dynamically crosslinked thermoplastic elastomer composition, and from the viewpoint of rationalization of the production process, recyclability, etc., automobile parts, building materials, home appliances, medical equipment parts, electric wires, miscellaneous goods Has attracted attention in a wide range of fields such as. In addition, it is known that the internal structure of the dynamically crosslinked thermoplastic elastomer composition is a sea-island structure in which the polyolefin resin is a sea and the ethylene / propylene / non-conjugated diene copolymer rubber is an island by dynamic crosslinking. .

For example, Patent Document 1 discloses heat obtained by dynamically heat treating an oil-extended ethylene copolymer rubber containing a copolymer ethylene rubber and a mineral oil softener and an olefin resin in the presence of a crosslinking agent. Plasticizable elastomeric compositions are disclosed.
On the other hand, in Patent Document 2 and Patent Document 3, various properties at the time of injection foam molding, for example, foam characteristics, flexibility, heat resistance, and the like are obtained by blending the thermoplastic elastomer composition with modified polypropylene exhibiting strain curing. Techniques to improve etc. are described.

Japanese Patent Application Laid-Open No. 11-269325 JP, 2011-102028, A JP, 2015-098542, A

Conventional thermoplastic elastomer compositions are not sufficient because they are inferior to rubber elasticity with compression set as an index compared to vulcanized rubber, and in severe applications where higher compression set is required. Replacement from vulcanized rubber is not in progress.
In the dynamically crosslinked thermoplastic elastomer composition described in Patent Document 1, in order to improve the properties of low hardness, it is necessary to reduce the amount of olefin resin and increase the amount of ethylene copolymer rubber and softener, When the amount of the softener is increased excessively, there is a problem that the softener bleeds out on the surface of a molded product obtained by molding the thermoplastic elastomer composition. Further, if the amount of the olefin resin is reduced too much, the particle size of the ethylene copolymer rubber can not be reduced by the olefin resin in the dynamic heat treatment stage, and a large particle size rubber fraction is exposed to obtain a molded product The problem arises that the appearance of the

  On the other hand, Patent Document 2 and Patent Document 3 only disclose that various performances in injection foam molding are improved by the incorporation of modified polypropylene exhibiting strain curability, and there is no suggestion about the improvement of compression set.

  The present invention has been made in view of such problems, and an object thereof is to provide a novel dynamically cross-linked thermoplastic elastomer composition which is low in hardness and excellent in molding appearance and compression set and a molded article thereof. It is in.

As a result of intensive studies to solve the above problems, the inventors of the present invention have hitherto found that polypropylene-based materials are considered to be unsuitable for thermoplastic elastomer compositions which have a hard touch and are used for molded articles with low hardness. Resin, among which, strain-hardening modified polypropylene, ethylene / α-olefin / non-conjugated diene copolymer rubber and softener for hydrocarbon rubber are subjected to dynamic heat treatment in the presence of a crosslinking agent It has been found that a dynamically crosslinkable thermoplastic elastomer composition can solve the above-mentioned problems, and the present invention has been completed.
That is, the gist of the present invention resides in the following [1] to [5].

[1] The content of the component (A) in the total 100 parts by mass of the components (A) and (B) containing the following components (A) to (D) is 70 to 90 parts by mass, the component (B) The content of component (C) is 10 to 30 parts by mass, and the content of component (C) is 0.05 to 20 parts by mass with respect to a total of 100 parts by mass of component (A) and component (B) The dynamically crosslinked thermoplastic elastomer composition having a content of 20 to 200 parts by mass, and a Duro A hardness of 60 or less according to JIS K6253.
Component (A): Ethylene / α-olefin / nonconjugated diene copolymer rubber Component (B): Melt flow rate (230 ° C., load 21.2 N, in accordance with JIS K 7210) for 0.1 to 250 g / 10 min, and Strain-curable modified polypropylene having a melt tension of 1.0 to 20 cN Component (C): Crosslinking agent Component (D): Softener for hydrocarbon rubber

[2] The dynamically crosslinked thermoplastic elastomer composition according to [1], wherein the component (B) is a strain-curable modified polypropylene having a long chain branched structure.

[3] The component (C) is at least one selected from the group consisting of organic peroxides, phenolic resins, silicon hydride compounds, polyfunctional vinyl compounds, polyfunctional (meth) acrylate compounds, and tin chloride Dynamically crosslinkable thermoplastic elastomer composition as described in [1] or [2].

[4] The dynamically crosslinked thermoplastic elastomer composition according to [3], wherein the component (C) is an organic peroxide.

[5] A molded article comprising the dynamically crosslinkable thermoplastic elastomer composition according to any one of [1] to [4].

According to the present invention, a novel dynamically crosslinked thermoplastic elastomer composition which is excellent in low hardness and compression set and has a good appearance when formed into a molded article, and a molded article using the same are provided. be able to.
The dynamically cross-linked thermoplastic elastomer composition of the present invention and a molded article using the same are developed into various applications exposed to severe usage environments where better mechanical strength and rubber elasticity are required. Can be expected.

  The embodiments of the present invention will be described in detail below, but the present invention is not limited to the following description, and can be arbitrarily modified and implemented without departing from the scope of the present invention. In addition, in this specification, when using and expressing a numerical value or a physical-property value in front of and behind that using "-", suppose that it uses as a thing including the value before and behind that.

[Dynamically Crosslinkable Thermoplastic Elastomer Composition]
The dynamically crosslinked thermoplastic elastomer composition of the present invention comprises the following components (A) to (D), and the content of component (A) in a total of 100 parts by mass of component (A) and component (B) Is 70 to 90 parts by mass, the content of the component (B) is 10 to 30 parts by mass, and the content of the component (C) relative to 100 parts by mass in total of the component (A) and the component (B) is 0. The content of the component (D) is 20 to 200 parts by mass, and the Duro A hardness in JIS K 6253 is 60 or less.
Component (A): Ethylene / α-olefin / nonconjugated diene copolymer rubber Component (B): Melt flow rate (230 ° C., load 21.2 N, in accordance with JIS K 7210) for 0.1 to 250 g / 10 min, and Strain-curable modified polypropylene having a melt tension of 1.0 to 20 cN Component (C): Crosslinking agent Component (D): Softener for hydrocarbon rubber

<Mechanism>
The mechanism that exerts the effect that the dynamically crosslinked thermoplastic elastomer composition of the present invention is low in hardness and excellent in compression set and has a good appearance when formed into a molded article is component (B), which has low hardness That is, even if the ratio of component (A) and component (D) is high, the particle diameter of component (A) can be reduced in the dynamic heat treatment step, and a good molded appearance and high rubber elasticity can be obtained. It is estimated to be.

<Component (A)>
The ethylene / α-olefin / non-conjugated diene copolymer rubber of component (A) is a copolymer containing ethylene, an α-olefin and a non-conjugated diene compound as copolymerization components. For ethylene / α-olefin / non-conjugated diene copolymer rubber, a mixture of ethylene / α-olefin / non-conjugated diene copolymer rubber and a softening agent for hydrocarbon type rubber (hereinafter referred to as “oil-extended ethylene · α- There are also oil-extended types which are sometimes referred to as “olefin / non-conjugated diene copolymer rubbers”) and non-oil-extended types which do not contain a softening agent for hydrocarbon rubber, and in the present embodiment oil Although an extended type copolymer rubber is intended, a low oil extended type or a non-oil extended type can also be suitably used. That is, in the present invention, the ethylene / α-olefin / nonconjugated diene copolymer rubber of the component (A) can be used either of oil extending type or non oil extending type, and non oil extending type or oil Only one type of expansion type may be used alone, or two or more types may be used in any combination and ratio, and one or more types of oil expansion type and one or two types of non oil expansion type Species or more may also be used in any combination and ratio.
Here, when the component (A) is an oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber, hydrocarbons contained in the oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber The rubber-based softener is contained in the hydrocarbon-based rubber softener as the component (D).

  The α-olefin in the component (A) is 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 such as hexene, 4-methyl-1-hexene, 1-heptene, 1-octene, 1-decene and 1-octadecene, and more preferably 3 to 8 carbon atoms, It is not particularly limited to these. Among these, propylene, 1-butene, 3-methyl-1-butene, and 1-pentene are preferable from the viewpoint of crosslinkability by a crosslinking agent at the time of dynamic crosslinking and bloomout suppression etc., more preferably propylene, 1-pentene. It is butene. In addition, only (alpha) -olefin can be used individually by 1 type, or 2 or more types can be used by arbitrary combinations and a ratio.

  As the nonconjugated diene compound in the component (A), dicyclopentadiene, 1,4-hexadiene, cyclohexadiene, cyclooctadiene, dicyclooctadiene, 1,6-octadiene, 5-methyl-1,4- Hexadiene, 3,7-dimethyl-1,6-octadiene, 1,3-cyclopentadiene, 1,4-cyclohexadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7- Ethylidene norbornene such as methyl-1,6-octadiene, tetrahydroindene, methyltetrahydroindene, 5-isopropylidene-2-norbornene, 5-vinyl-2-norbornene, vinylidene norbornene, 5-ethylidene-2-norbornene (ENB), etc. Methylene such as 5-methylene-2-norbornene (MNB) Norbornene and the like, but not particularly limited thereto. Among these, dicyclopentadiene, ethylidene norbornene and vinylidene norbornene are preferable from the viewpoint of crosslinkability by a crosslinking agent at the time of dynamic crosslinking, and more preferably dicyclopentadiene, 5-ethylidene-2-norbornene and vinylidene norbornene. . In addition, nonconjugated diene can be used individually by 1 type alone, or 2 or more types can be used by arbitrary combinations and ratios.

  Specific examples of the ethylene / α-olefin / nonconjugated diene copolymer rubber include ethylene / propylene • 5-ethylidene-2-norbornene copolymer rubber, ethylene / propylene / dicyclopentadiene copolymer rubber, ethylene / propylene · Ethylene · propylene · non-conjugated diene copolymer rubber (EPDM) such as 1,4-hexadiene copolymer rubber, ethylene · propylene · 5-vinyl-2-norbornene copolymer rubber, ethylene · 1-butene Examples thereof include 5-ethylidene-2-norbornene copolymer rubber and the like, but are not particularly limited thereto. Among these, ethylene / propylene / non-conjugated diene copolymer rubber (EPDM) is preferable from the viewpoint of crosslinkability by a crosslinking agent at the time of dynamic crosslinking and bloomout suppression. The ethylene / α-olefin / non-conjugated diene copolymer rubber can be used alone or in any combination of two or more in any proportion.

  The content of the ethylene unit in the ethylene / α-olefin / nonconjugated diene copolymer rubber is not particularly limited, but is preferably 50 to 90% by mass, more preferably 55 to 85% by mass, and still more preferably 60 It is -80 mass%. If the content of the ethylene unit is within the above-mentioned preferable range, a dynamic crosslinkable thermoplastic elastomer composition having excellent mechanical strength and rubber elasticity tends to be easily obtained.

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

  Furthermore, the content of the nonconjugated diene unit in the ethylene / α-olefin / nonconjugated diene copolymer rubber is not particularly limited, but is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass And more preferably 2 to 10% by mass. If the content of the non-conjugated diene unit is within the above-mentioned preferable range, adjustment of crosslinkability and moldability becomes easy, and a dynamic crosslinkable thermoplastic elastomer composition having excellent mechanical strength and rubber elasticity tends to be easily obtained. is there.

  In addition, content of each structural unit of a component (A) can be calculated | required by infrared spectroscopy.

  In the present invention, as the component (A), in particular, the content of ethylene units is 55 to 75% by mass, the content of propylene units is 15 to 40% by mass, and dicyclopentadiene, 5-ethylidene-2 Ethylene-propylene-nonconjugated diene copolymer rubber copolymer in which the content of at least one nonconjugated diene unit selected from the group consisting of norbornene and vinylidene norbornene is 1 to 10% by mass is preferable.

  In addition, as a manufacturing method of components (A), such as ethylene propylene non-conjugated diene copolymer rubber (EPDM), the well-known polymerization method using the well-known catalyst for olefin polymerization can be applied. For example, EPDM can be produced by a slurry polymerization method, a solution polymerization method, a bulk polymerization method, a gas phase polymerization method or the like using a complex catalyst such as a Ziegler-Natta catalyst, a metallocene complex or a nonmetallocene complex. . Here, the Ziegler-Natta catalyst is a polymerization catalyst comprising a titanium compound or a vanadium compound and an organoaluminum compound, and the metallocene complex catalyst is a cyclopentadienyl derivative of a transition metal such as titanium or zirconium and a cocatalyst. It is a highly active polymerization catalyst consisting of Generally, a solution polymerization method mainly using aliphatic hydrocarbon as a solvent is adopted, and a slurry polymerization method mainly using a monomer as a main solvent is also adopted. In addition, a gas phase polymerization method in which a polymerization reaction is advanced using various inactive materials (for example, carbon black) as a dispersant in a monomer gas is also industrialized. The synthesis by the solution polymerization method is different from the gas phase polymerization method, and since the polymer does not contain carbon black and the like, it is excellent in suppression of bloomout. Furthermore, when the metallocene complex catalyst is used, the effect of suppressing the bloomout is better. On the other hand, in the synthesis by the gas phase polymerization method, a polymer having a higher molecular weight can be synthesized than the solution polymerization method or the slurry polymerization method. As a result, the Mooney viscosity can be increased, which is effective for improving oil resistance and compression set. .

  The mass average molecular weight in terms of polypropylene by gel permeation chromatography method (GPC method) of ethylene / α-olefin / nonconjugated diene copolymer rubber of component (A) is not particularly limited, but it is 100,000 or more. Preferably, it is more preferably 200,000 or more, still more preferably 300,000 or more, and preferably 1,000,000 or less, more preferably 900,000 or less, and still more preferably 800,000 or less. . When the mass average molecular weight of the ethylene / α-olefin / nonconjugated diene copolymer rubber of the component (A) is within the above-mentioned preferable range, the moldability, the processability and the like are improved, and the hydrocarbon of the component (D) It tends to be easy to suppress the bleed out of the softening agent for a rubber system.

In addition, in this specification, the measurement conditions of the mass mean molecular weight of polypropylene conversion based on the GPC method of ethylene-alpha-olefin nonconjugated diene copolymer rubber of a component (A) are as follows.
Equipment: Waters 150C
Column: Shodex AD 806 MS x 3 (8.0 mm id x 300 mm length)
Detector: IR (Dispersive type, 3.42 μm)
Solvent: ODCB (o-dichlorobenzene)
Temperature: 140 ° C
Flow rate: 1.0 mL / min Injection volume: 200 μL
Concentration: 10 mg / mL
Calibration sample: Polydispersed standard polyethylene Calibration method: Converted into polypropylene using Mark-Houwink equation

The density of the ethylene / α-olefin / nonconjugated diene copolymer rubber of the component (A) 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 0.900 g / cm ³ or less, more preferably 0.890 g / cm ³ 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, a thermoplastic elastomer composition excellent in processability, moldability, flexibility and the like can be easily obtained There is a tendency. The density can be measured based on JIS K7112: 1999.

The Mooney viscosity (ML _{1 + 4} , 125 ° C.) of the non-oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber (ethylene / α-olefin / non-conjugated diene copolymer rubber before oil extension) of component (A) is The Mooney viscosity (ML _{1 + 4} , 125 ° C.) of the oil-extended ethylene / α-olefin / conjugated diene copolymer rubber is preferably 15 to 400, more preferably 30 to 300, but not particularly limited, although it is not particularly limited. , Preferably 15 to 100, more preferably 30 to 80. The Mooney viscosity of the component (A) is preferable from the viewpoint of improving the appearance of the molded article obtained to be above the above lower limit value, and is preferably below the above upper limit value from the viewpoint of moldability and low temperature impact resistance .

In the present invention, the Mooney viscosity (ML _{1 + 4} at 125 ° C.) of the component (A) ethylene-α-olefin-conjugated diene copolymer rubber before oil-extended is as described in JP-A-1-103639. Calculated by the method of That is, the following ML ₁ can be measured, and the ML ₂ (the Mooney viscosity (ML _{1 +4} at 125 ° C.) of the component (A)) can be obtained as a calculated value.
Calculation formula: log (ML ₁ / ML ₂ ) = 0.0066 (ΔPHR)
ML ₁ : Mooney viscosity before oil expansion of oil-extended ethylene / α-olefin / nonconjugated diene copolymer rubber ML ₂ : Mooney viscosity of oil-extended ethylene / α-olefin / nonconjugated diene copolymer rubber ΔPHR: ethylene / α Oil spread per 100 parts by mass of olefin / nonconjugated diene copolymer rubber

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

  Examples of softeners for hydrocarbon rubbers used for oil-extended ethylene / α-olefin / conjugated diene copolymer rubbers include softeners for mineral oil rubbers, softeners for synthetic resin rubbers, and the like. From the viewpoint of affinity with other components, a softener for mineral oil-based rubber is preferred. The softener for mineral oil type rubber is generally a mixture of aromatic hydrocarbon, naphthene type hydrocarbon and paraffin type hydrocarbon, and the proportion of carbon of paraffin type hydrocarbon is 50% by mass to total carbon atoms The above items are paraffin oil, naphthene hydrocarbon 30 to 45 mass% carbon ratio naphthene oil, aromatic hydrocarbon carbon ratio 35 mass% or more aromatic oil is called. Among these, as a softener for hydrocarbon-based rubber of oil-extended ethylene / α-olefin / conjugated diene copolymer rubber of component (A), a softener for paraffin-based rubber (paraffin-based oil) is preferable. The hydrocarbon-based rubber softener may be used alone or in any combination of two or more, in any proportion.

  The paraffinic oil used for the oil-extended ethylene / α-olefin / nonconjugated diene copolymer rubber of the component (A) is not particularly limited, but the dynamic viscosity at 40 ° C. is usually 20 cst (centistokes) or more, preferably 50 cst It is the above and is usually 800 cst or less, preferably 600 cst or less. The pour point is usually −40 ° C. or more, preferably −30 ° C. or more and 0 ° C. or less. The pour point is usually −40 ° C. or more, preferably −30 ° C. or more and 0 ° C. or less. Furthermore, the flash point (COC) is usually 200 ° C. or more, preferably 250 ° C. or more, and usually 400 ° C. or less, preferably 350 ° C. or less is suitably used.

  Content ratio of ethylene / α-olefin / non-conjugated diene copolymer rubber and hydrocarbon-based rubber softener when oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber is used as component (A) The content of the softening agent for hydrocarbon rubber is usually 10 parts by mass or more, and preferably 20 parts by mass, with respect to 100 parts by mass of ethylene / α-olefin / non-conjugated diene copolymer rubber, though not particularly limited. The amount is usually 200 parts by mass or less, preferably 160 parts by mass or less, and more preferably 120 parts by mass or less.

  The method (oil extending method) for preparing the oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber is not particularly limited, and a known method can be used. As an oil extending method, for example, a method of mechanically kneading and oil extending an ethylene / α-olefin / non-conjugated diene copolymer rubber and a softening agent for hydrocarbon rubber using a mixing roll or a Banbury mixer, ethylene · A method of adding a predetermined amount of a softening agent for a hydrocarbon-based rubber to an α-olefin · non-conjugated diene copolymer rubber and thereafter removing the solvent by a method such as steam stripping, crumb-like ethylene · α-olefin · non- Examples thereof include a method in which a mixture of a conjugated diene copolymer rubber and a softening agent for a hydrocarbon-based rubber is stirred and impregnated with a Henschel mixer or the like. From the viewpoint of preparing a high molecular weight oil-extended ethylene / α-olefin / nonconjugated diene copolymer rubber, the polymerization reaction solution or suspension of the component (A) ethylene / α-olefin / nonconjugated diene copolymer rubber A preferred method is to remove the solvent after adding a predetermined amount of a hydrocarbon-based rubber softener to the liquid.

  In addition, as ethylene (alpha) -olefin nonconjugated diene copolymer rubber | gum of a component (A), many things of various grades are marketed from the maker inside and outside the country, and the commercial item can be used. Examples of commercially available products include JSR EPR manufactured by JSR, Mitsui EPT manufactured by Mitsui Chemicals, Esprene (registered trademark) manufactured by Sumitomo Chemical, Keltan (registered trademark) manufactured by ARLAN XEO, and the like.

<Component (B)>
The modified polypropylene of the component (B) is a polypropylene-based resin (a homopolymer of propylene or a propylene-based copolymer, hereinafter referred to as a "propylene-based (co) polymer") exhibiting strain hardening. is there. Here, "strain hardening" means a phenomenon in which the viscosity increases with an increase in the stretching strain of the melt, and in the present invention, the presence or absence of "strain hardening" is measured when melt tension is measured under the conditions described later. It can be judged from the fracture behavior of the molten strand, and when the take-up speed is increased, the take-up load increases rapidly, and when it comes to cutting, it is judged to exhibit strain hardening.

  Modified polypropylene exhibiting strain hardening of component (B) has a melt flow rate of 0.1 to 250 g / 10 min (MFR, 230 ° C., load 21.2 N, in accordance with JIS K 7210), and 1.0 to 20 cN It has melt tension.

  The MFR of the modified polypropylene exhibiting the strain curability of the component (B) is more preferably 0.3 g / 10 min or more and 100 g / 10 min or less, further preferably 0.5 g / min from the viewpoint of formability and the like. 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 strain curability of component (B) is preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, most preferably 10 g / 10 min It is below. Here, MFR of the modified polypropylene which shows the strain hardening property of a component (B) is a value measured by 230 degreeC and the load 2.12N based on JISK7210.

  The melt tension of the modified polypropylene exhibiting strain curability of the component (B) is more preferably 1.5 to 19 cN, further preferably 2.0 to 18 cN, from the viewpoints of moldability and compression set. , Particularly preferably 2.5 to 15 cN.

Here, the measuring method of melt tension is as follows.
That is, using a capilograph (made by Toyo Seiki Seisakusho Co., Ltd.) equipped with a melt tension measurement attachment and equipped with a φ10 mm cylinder fitted with an orifice of φ1 mm and 10 mm in length at the tip, the piston lowering speed 10 mm / The strand discharged from the die when it is lowered by a minute is hung on a load cell equipped pulley under 350 mm and taken at a speed of 1 m / min, and after stabilization, the take-up speed is increased at a rate to reach 200 m / min in 4 min. The load applied to the load cell equipped pulley when the strand breaks is measured, and this measured load is taken as the melt tension.

  The type of modified polypropylene exhibiting strain curing property of the component (B) is not particularly limited, and is a propylene homopolymer, or a propylene-based copolymer which is a block copolymer or random copolymer of propylene and another copolymer component. Any copolymer may be used. In addition, a component (B) can be used individually by 1 type individually, or can use 2 or more types by arbitrary combinations and a ratio. Here, a propylene-based copolymer means that whose content of a propylene unit is more than 50 mass%. The content of the propylene unit in the propylene-based copolymer is preferably 60% by mass or more, more preferably 75% by mass or more, and still more preferably 90% by mass from the viewpoints of heat resistance, rigidity, crystallinity, chemical resistance and the like. % Or more. On the other hand, the upper limit is not particularly limited, but is usually less than 100% by mass. The content of each of the constituent units of the propylene unit in the component (B) and the other copolymerization components described below can be determined by infrared spectroscopy.

  When the modified polypropylene exhibiting the strain curability of the component (B) is a propylene-based block copolymer or a random copolymer, ethylene, 1-butene, 1-, etc. may be used as the other copolymer component copolymerized with propylene. Butene, 2-methylpropylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc. Olefins; 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-hexadiene And dienes such as methyl-1,4-hexadiene, 7-methyl-1,6-octadiene; vinyl chloride, vinylidene chloride, acrylonitrile Vinyl monomers such as vinyl acetate, acrylic acid, methacrylic acid, maleic acid, ethyl acrylate, butyl acrylate, methyl methacrylate, maleic anhydride, styrene, methylstyrene, vinyltoluene, divinylbenzene etc. may be mentioned. It is not particularly limited to these. These other copolymerization components can be used alone or in any combination and ratio of two or more. Among these, ethylene and 1-butene are preferable.

  Here, when the component (B) is a propylene-based block copolymer, a propylene-based block copolymer obtained by polymerization in multiple steps is preferable. For example, a propylene-based block copolymer obtained by polymerizing polypropylene in the first stage and polymerizing a propylene / ethylene copolymer in the second stage is preferably used.

  Further, as the component (B), a propylene-based (co) polymer having a branched structure, a propylene-based (co) polymer having a high molecular weight component, and the like are preferably used. As such a propylene-based (co) polymer, for example, a linear propylene-based resin such as a crystalline propylene homopolymer, a propylene homopolymer, a block copolymer, a random copolymer, etc. A polypropylene resin, a conjugated diene compound, a crystalline propylene (co) polymer obtained by melt-mixing a radical polymerization initiator, and the like can be mentioned. Among these, those having a branched structure are preferable.

  It does not specifically limit as a manufacturing method of the modification polypropylene which shows distortion hardening nature of ingredient (B), for example, a publicly known polymerization method using a publicly known catalyst for olefin polymerization can be applied, and its example is, A multistage polymerization method using a Ziegler-Natta catalyst can be mentioned. A slurry polymerization method, a solution polymerization method, a bulk polymerization method, a gas phase polymerization method, etc. can be used for this multistage polymerization method, You may manufacture combining these 2 or more types.

  It is preferable that the modified polypropylene which shows the distortion-hardening property of the component (B) used for this invention has a long-chain branched structure.

For the long chain branched structure, Macromol. Chem. Phys. 2003, vol. The detailed description is given in 204 and 1738, but it is as follows.
The propylene-based (co) polymer having a long chain branched structure has a specific branched structure as shown in the following structural formula (1). In structural formula (1), Ca, Cb, and Cc represent methylene carbon adjacent to a branched carbon, Cbr represents methine carbon at the base of a branched chain, and P1, P2, and P3 are propylene-based (co) heavy The combined residue is shown.
P1, P2 and P3 may contain, in themselves, another branched carbon (Cbr) other than Cbr described in Structural Formula (1).

Such branched structures are identified by ¹³ C-NMR analysis. Assignment of each peak is described in Macromolecules, Vol. 35, no. 10. 2002, pages 3839-3842 can be referred to. That is, a total of three methylene carbons (Ca, Cb, Cc) are observed at 43.9 to 44.1 ppm, 44.5 to 44.7 ppm and 44.7 to 44.9 ppm, respectively, 31.5 Methine carbon (Cbr) is observed at ̃31.7 ppm. The methine carbon observed in the above 31.5 to 31.7 ppm may be abbreviated as branched methine carbon (Cbr) hereinafter.
It is characterized in that three methylene carbons adjacent to the branched methine carbon Cbr are observed as being divided into three nonequivalently to the diastereotopic.
Such a branched chain assigned by ¹³ C-NMR indicates a propylene-based (co) polymer residue having 5 or more carbon atoms branched from the main chain of a propylene-based (co) polymer, and also having 4 or less carbon atoms In the present invention, the presence or absence of a long chain branched structure can be determined by confirming the peak of branched methine carbon in the present invention because the branch position of the branched carbon can be distinguished by the difference in the peak position of the branched carbon.
In addition, about the measuring method of < ¹³ > C-NMR in this invention, it is as follows.

( ¹³ C-NMR measurement method)
An NMR sample with an inner diameter of 10 mmφ with 200 mg of sample together with 2.4 ml of o-dichlorobenzene / deuterated brominated benzene (C ₆ D ₅ Br) = 4/1 (volume ratio) and hexamethyldisiloxane which is a standard substance of chemical shift Place in tube and dissolve, and perform ¹³ C-NMR measurement.
^{The 13} C-NMR measurement is performed using an AV400M NMR apparatus manufactured by Bruker Biospin Ltd. equipped with a 10 mmφ cryoprobe.
The measurement is carried out by the proton complete decoupling method at a temperature of 120 ° C. of the sample. Other conditions are as follows.
Pulse angle: 90 °
Pulse interval: 4 seconds Integration number: 20000 The chemical shift was set with the methyl carbon peak of hexamethyldisiloxane as 1.98 ppm, and the chemical shifts of the peaks due to other carbons were based on this.
The peak around 44 ppm can be used to calculate the amount of long chain branching.

The modified polypropylene having a long chain branching structure according to the present invention is characterized in that the amount of long chain branching quantified from the peak at around 44 ppm in the ¹³ C-NMR spectrum is 0.01 pieces / 1,000 total propylene (1,000 total carbon atoms forming carbon Is preferably not less than 0.03, more preferably not less than 0.03 / 1000 total propylene, still more preferably not less than 0.05 / 1000 total propylene, preferably not more than 1.00 / 1000 total propylene, more preferably Is not more than 0.50 / 1000 total propylene, more preferably not more than 0.30 / 1000 total propylene. Within this range, it is possible to obtain a polypropylene-based resin which has no or little gel and a high degree of strain hardening.

  Further, in the modified polypropylene having a long chain branch structure according to the present invention, the lower limit is 0.3 or more in the order of preferable lower limit in the absolute molecular weight Mabs 1,000,000 for the branch index g ′ known as a direct index regarding long chain branch It is 0.55 or more, 0.75 or more, 0.78 or more, and the upper limit is less than 1.0, 0.98 or less, 0.96 or less, 0.95 or less in order of preference. The above lower limit and the upper limit can be any combination. When the branching index g 'is in the range between any of the above-mentioned preferable lower limits and any of the above-mentioned preferable upper limits, highly cross-linked components are not formed, which is preferable in terms of molding appearance. The most preferable range of the branching index g 'in the present invention is in the range of 0.78 to 0.95.

Branching index g 'is known as a direct indicator for long chain branching. The branching index g ′ is described in detail in “Developments in Polymer Characterization-4” (J. V. Dawkins ed. Applied Science Publishers, 1983), and its definition is as follows.
Branching index g ': [η] br / [η] lin
[Η] br: Intrinsic viscosity of polymer (br) having a long chain branched structure [η] lin: Intrinsic viscosity of linear polymer having the same molecular weight as the polymer (br)

  As apparent from the above definition, when the branching index g 'takes a value smaller than 1, it is judged that a long chain branching structure is present, and the value of the branching index g' becomes smaller as the long chain branching structure increases. .

  The branching index g 'can be obtained as a function of the absolute molecular weight Mabs by using GPC with a light scatterometer and viscometer on the detector. Although the measuring method of branching index g 'in this invention is described in detail in Unexamined-Japanese-Patent No. 2015-40213, it is as follows.

<Measurement method>
GPC: Alliance GPCV 2000 (Waters)
Detector: listed in order of connection Multi-angle laser light scattering detector (MALLS): DAWN-E (Wyatt Technology)
Differential Refractometer (RI): attached to GPC Viscosity detector (Viscometer): attached to GPC Mobile phase solvent: 1,2,4-trichlorobenzene (Irganox 1076 added at a concentration of 0.5 mg / mL)
Mobile phase flow rate: 1 mL / min Column: Two Tohso GMHHR-H (S) HT connected Sample injection temperature: 140 ° C
Column temperature: 140 ° C
Detector temperature: All 140 ° C
Sample concentration: 1 mg / mL
Injection volume (sample loop volume): 0.2175 mL

<Analysis method>
Data processing included with MALLS to determine absolute molecular weight (Mabs), root mean square radius of inertia (Rg) obtained from multi-angle laser light scattering detector (MALLS), and intrinsic viscosity ([η]) obtained from Viscometer The software ASTRA (version 4.73.04) is used, and calculations are performed with reference to the following documents.
References:
1. "Developments in Polymer Characterization-4" (J.V. Dawkins ed. Applied Science Publishers, 1983. Chapter 1.)
2. Polymer, 45, 6495-6505 (2004)
3. Macromolecules, 33, 2424-2436 (2000)
4. Macromolecules, 33, 6945-6952 (2000)

  Such strain-hardened modified polypropylene having a long chain branched structure is produced by a method using a macromer copolymerization method in which a long chain branched structure is formed upon polymerization. Examples of this method are, for example, JP 2001-525460 A, JP 10-338717 A, JP 2002-523575 A, JP 2009-57542 A, JP 05027353 A, JP 10 The method etc. which are disclosed by the -338717 gazette are mentioned. In particular, the macromer copolymerization method of JP-A-2009-57542 is suitable for the present invention.

  In addition, as a modification | reformation polypropylene which shows the distortion-hardening property of a component (B), many thing of various grade is marketed from the maker inside and outside the country, and the commercial item can be used. Examples of commercially available products include Prim Polypro (registered trademark) manufactured by Prime Polymer Co., Ltd., Sumitomo Nobrene (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., polypropylene block copolymer manufactured by Sun Aroma Co., Ltd., Novatec (registered trademark) PP manufactured by Japan Polypro , Waymax (WAYMAX (registered trademark)), Moplen (registered trademark) manufactured by LyondellBasell, ExxonMobil PP manufactured by ExxonMobil, Formolone (registered trademark) manufactured by Formosa Plastics, Borealis PP manufactured by Borealis, manufactured by LG Chemical SEETEC PP, A. ASI POLYPROPYLENE manufactured by Schulman, INEOS PP manufactured by INEOS Olefins & Polymers, Braskem PP manufactured by Braskem, Sumsung Total manufactured by SAMSUNG TOTAL PETROCHEMICALS, Sabic (registered trademark) PP manufactured by Sabic, TOTAL PETROCHEMICALS manufactured by TOTAL PETROCHEMICALS And YUPLENE (registered trademark) manufactured by SK Corporation. Among them, waymax is suitably used as polypropylene having a long chain branched structure and exhibiting strain hardening.

<Component (C)>
The crosslinking agent of the component (C) partially crosslinks the component (A) mentioned above in the resin composition containing each component in dynamic heat treatment, whereby the composition of the dynamically crosslinked thermoplastic elastomer is obtained. Things are realized. Such a crosslinking agent can be appropriately selected from known ones and used, and is not particularly limited, but organic peroxides and phenol resins are preferably used. In addition, a crosslinking agent can be used individually by 1 type individually, or can use 2 or more types by arbitrary combinations and a ratio.

  Examples of the organic peroxide of the component (C) include aromatic organic peroxides and aliphatic organic peroxides. Specifically, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl 2,5-Di (t-butylperoxy) hexyne-3, 1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-di (t-butylperoxy) -3,3,5 Dialkyl peroxides such as trimethylcyclohexane; t-butyl peroxybenzoate, t-butyl peroxy isopropyl carbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2 Peroxy esters such as 5-di (benzoylperoxy) hexyne-3; acetyl peroxide, lauroyl peroxide, benzoyl Peroxide, p- chlorobenzoyl peroxide, 2,4-dichlorobenzoyl but hydroperoxides such peroxide such like, not particularly limited thereto. Among these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane is preferable.

  As a phenol resin of a component (C), an alkyl phenol formaldehyde, the brominated alkyl phenol phenol formaldehyde, etc. are mentioned. These phenol resins may be used alone or in combination of two or more.

  As a phenol resin of component (C), a non-halogen based phenol resin is particularly preferable, and specifically, one represented by the following formula (I) is preferable.

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

  Examples of the non-halogen based phenolic resin include Tackirol 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 Vulkaresat 510E, 532E, Vulkaresen E, 105E, 130E, Vulkaresol 315E (trade name), Amberol ST 137X (trade name) manufactured by Rohm & Haas, Sumite resin PR-22193 (trade name) manufactured by Sumitomo Durez Co., Ltd., Anchor Chem. Symphorm-C-100, C-1001 (trade name), manufactured by Arakawa Chemical Industry Co., Ltd., Tamanor 531 (trade name), Schenectady Chem. Manufactured by Schenectady SP 1045, SP 1055, SP 1056, SP 1059 (trade name), U.S. Pat. C. Examples thereof include CRR-0803 (trade name) manufactured by Company C, CRM-0803 (trade name) manufactured by Showa Union Gosei Co., Ltd., Vulkadur A (trade name) manufactured by Bayer Corp., and the like.

  As the non-halogenated phenol resin of component (C), p-octylphenol formaldehyde resin represented by the following formula (II) is particularly preferably used, among which those having a mass average molecular weight of 2,500 to 4,000 are most preferable. It is preferably used. As this non-halogen based phenol resin, those commercially available as the above-mentioned Tackirol 201, 202 (trade name) can be used.

In addition to the above-mentioned organic peroxides and phenol resins, other crosslinking agents may be used, for example, silicon hydride compounds such as metro hydrogen silicon, sulfur, p-quinone dioxime, p-di Auxiliary agents for peroxides such as nitrosobenzene and 1,3-diphenylguanidine; polyfunctional vinyl compounds such as divinylbenzene, triallyl cyanurate, triallyl isocyanurate and diallyl phthalate; ethylene glycol di (meth) acrylate and diethylene glycol di (Meth) acrylates, polyethylene glycol di (meth) acrylates, trimethylolpropane tri (meth) acrylates, polyfunctional (meth) acrylate compounds such as allyl (meth) acrylates; N, N'-m-phenylenebismaleimide, N, N'-m- toluylene bis Compounds having a bismaleimide structure such Reimido; trimethylolpropane, trimethylolpropane trimethacrylate, tin chloride (SnCl _2), and the like. Among these, divinylbenzene is preferred.

  In addition, a crosslinking agent can be used individually by 1 type individually, or can use 2 or more types by arbitrary combinations and a ratio.

  As the crosslinking agent of the component (C), it is more preferable to use at least an organic peroxide, particularly from the viewpoint of the balance between the rubber elasticity and the molding appearance.

  Among those commercially available as crosslinking agents, there are those containing a softening agent for a hydrocarbon-based rubber corresponding to the component (D) described later and a filler, and the crosslinking agent to be used is for hydrocarbon-based rubbers. When a softener is contained, the softener for hydrocarbon rubbers shall be contained in the softener for hydrocarbon rubbers as ingredient (D). The same applies to fillers.

<Component (D)>
The dynamically cross-linked thermoplastic elastomer composition of the present invention contains a hydrocarbon-based rubber softener as a component (D) from the viewpoint of enhancing the flexibility and elasticity and improving the processability and flowability. In addition, when using oil-extended ethylene-alpha-olefin nonconjugated diene copolymer rubber as this component (A) for this component (D), the softener for hydrocarbon type rubbers contained in it is Even when an oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber is used as the component (A), a component (A) is contained separately from the oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber A hydrocarbon-based rubber softener may be separately added as D). In this case, the softener for hydrocarbon rubber to be separately added is the same as, the same as, or different from the softener for hydrocarbon rubber in the oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber of component (A) Any of the hydrocarbon-based rubber softeners described in the above can be used. The same applies to the case where the hydrocarbon-based rubber softener is contained in the crosslinking agent of the component (C).

  As a softening agent for hydrocarbon rubbers added separately from the component (A), for example, a softening agent for mineral oil rubbers, a softening agent for synthetic resin rubbers, etc. may be mentioned, among them, the affinity with other components From the viewpoint of properties and the like, softeners for mineral oil-based rubbers are preferred. As mentioned above, the softener for mineral oil-based rubber is generally a mixture of aromatic hydrocarbon, naphthenic hydrocarbon and paraffinic hydrocarbon, and the ratio of carbon of paraffinic hydrocarbon to total carbon atoms 50% by weight or more is paraffin oil, that of naphthene hydrocarbon 30% to 45% by weight is naphthene oil, carbon of aromatic hydrocarbon is 35% by weight or more It is called aromatic oil. Among these, as a softening agent for hydrocarbon rubber, a softening agent for liquid hydrocarbon rubber which is liquid at normal temperature (23 ± 2 ° C.) is preferable, and a liquid paraffin oil which is liquid at normal temperature is more preferable. By using a softener for liquid hydrocarbon rubber as a softener for hydrocarbon rubber, it is possible to increase the flexibility and elasticity of the dynamic crosslinkable thermoplastic elastomer composition of the present invention, and to process and flow it. There is a tendency for the nature to improve dramatically. The hydrocarbon-based rubber softener may be used alone or in any combination of two or more in any proportion.

  The paraffinic oil is not particularly limited, but the kinematic viscosity at 40 ° C. is 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 more, preferably −30 ° C. or more and 0 ° C. or less. The pour point is usually −40 ° C. or more, preferably −30 ° C. or more and 0 ° C. or less. Furthermore, the flash point (COC) is usually 200 ° C. or more, preferably 250 ° C. or more, and usually 400 ° C. or less, preferably 350 ° C. or less is suitably used.

  Even when using oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber as the component (A), the component (D) can be obtained by separately adding a hydrocarbon rubber softener as the component (D) The content ratio of the softener for hydrocarbon type rubber of D) is arbitrarily adjusted without depending on the content ratio of the softener for hydrocarbon type rubber in oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber It is possible.

<Blending ratio>
In the dynamically crosslinked thermoplastic elastomer composition of the present invention, the content of the component (A) and the component (B) is 70 to 90 parts by mass of the component (A) and 10 to 30 parts by mass of the component (B) However, it shall be 100 mass parts in the sum total of a component (A) and a component (B). If the content of the component (A) is more than the above upper limit and the content of the component (B) is less than the above lower limit, the molding appearance deteriorates, conversely the content of the component (B) is less than the above lower limit, the component (B) When the content of (C) exceeds the above upper limit, the hardness becomes high and the rubber elasticity is lost. From this viewpoint, the content of component (A) in a total of 100 parts by mass of component (A) and component (B) is 75 to 90 parts by mass, and the content of component (B) is preferably 10 to 25 The content of the component (A) is preferably 75 to 85 parts by mass, and the content of the component (B) is more preferably 15 to 25.
Here, when using the oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber as the component (A), the content of the component (A) does not include a softening agent for hydrocarbon rubber. It is content as an ethylene-alpha-olefin nonconjugated diene copolymer rubber.

  In addition, the content of the crosslinking agent (including the crosslinking assistant) of the component (C) with respect to a total of 100 parts by mass of the component (A) and the component (B) is 0.05 mass from the viewpoint of sufficiently advancing the crosslinking reaction. Or more parts, preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more. On the other hand, the content of the component (C) is 20 parts by mass or less, preferably 10 parts by mass or less, more preferably, from the viewpoint of controlling the crosslinking reaction with respect to 100 parts by mass in total of the component (A) and the component (B). Is 8 parts by mass or less, more preferably 6 parts by mass or less, and particularly preferably 4 parts by mass or less.

Moreover, content of the component (D) with respect to a total of 100 mass parts of a component (A) and a component (B) is 20-200 mass parts. If the content of the component (D) is less than the above lower limit, the effect of improving the flexibility, elasticity, flowability and processability by the component (D) can not be sufficiently obtained, and if it exceeds the above upper limit, it bleeds out from the surface There is a fear. From this viewpoint, the content of the component (D) relative to a total of 100 parts by mass of the component (A) and the component (B) is preferably 50 to 170 parts by mass, and more preferably 70 to 150 parts by mass .
Here, the content of the component (D) means the hydrocarbon-based rubber in the component (A) when oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber is used as the component (A) Content of the total of the softener for hydrocarbon rubber and the softener for hydrocarbon rubber as the component (D) separately added to the component (A), and the softener for hydrocarbon rubber in the component (C) When it contains, it is the content of the sum also containing the softening agent for the hydrocarbon type rubber concerned.

<Other ingredients>
In the dynamically crosslinked thermoplastic elastomer composition of the present invention, as long as the object of the present invention is not impaired, other components other than the components (A) to (D) (simply referred to herein simply) May be referred to as "other components". As other components, resins and elastomers other than the components (A) and (B) (these may be simply referred to as "other resins" in this specification) and various additives may be mentioned.

  Other resins that may be contained in the dynamically cross-linked thermoplastic elastomer composition of the present invention include polyolefin resins (but excluding those corresponding to the component (B)), polyester resins, polyamide resins, styrene resins, Resins such as acrylic resin, polycarbonate resin, polyvinyl chloride resin, and olefin-based elastomers such as ethylene / propylene copolymer rubber (EPM), ethylene / butene copolymer rubber (EBM), ethylene / propylene / butene copolymer rubber; polyamide · Polyamide-based elastomers such as polyol copolymers; polyvinyl chloride-based elastomers and polybutadiene-based elastomers, hydrogenated products thereof, those modified with acid anhydrides and the like to introduce polar functional groups, and other units The body is also grafted, random and / or block copolymerized Etc. The. The other resins listed above may contain only one or two or more.

  Among these, as polyolefin resin, the copolymer which has as a main component the single or C2-C4 alpha-olefins, such as ethylene, propylene, 1-butene, is mentioned. Specifically, these polyolefin resins are not limited to homopolymers such as polyethylene, polypropylene, poly-1-butene, etc., and other carbon atoms having 5 carbons as long as they have an α-olefin of 2 to 4 carbon atoms as the main component. To 20 α-olefins or copolymers with vinyl compounds such as vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, styrene and the like. Furthermore, it may be a graft copolymer graft modified with an unsaturated carboxylic acid such as maleic anhydride, maleic acid or acrylic acid or a derivative thereof. Furthermore, these polyolefin resins may be a mixture.

When the dynamically cross-linked thermoplastic elastomer composition of the present invention contains a polyolefin resin such as polypropylene (but excluding those corresponding to the component (B)), the content is the component (A) and the component (A) Preferably it is 0.1-40 mass parts per a total of 100 mass parts of B).
The dynamically crosslinked thermoplastic elastomer composition of the present invention has a strain resistance of polyolefin resin, in particular, a melt flow rate (230 ° C., 21.18 N, in accordance with JIS K 7210) of 0.1 to 2,000 g / 10 min. By containing polypropylene which is not shown, it is possible to control to desired flowability and mechanical properties.

  When the dynamically crosslinked thermoplastic elastomer composition of the present invention contains another resin such as a polyolefin resin, the total content of the other resins in the dynamically crosslinked thermoplastic elastomer composition of the present invention is It is preferable to set it as 40 mass parts or less with respect to a total of 100 mass parts of a component (A) and a component (B), and it is more preferable to set it as 30 mass parts or less.

  Moreover, as an additive which the dynamically crosslinked thermoplastic elastomer composition of the present invention may contain, a light processing stability such as an antioxidant, a crystal nucleating agent, a molding processing aid such as a lubricant, an ultraviolet light absorber, a hindered amine compound, etc. Agents, hydrolysis resistance improvers, pigments, colorants such as dyes, antistatic agents, conductive agents, flame retardants, reinforcing agents, fillers, plasticizers, mold release agents, foaming agents and the like.

  For example, in the dynamically crosslinked thermoplastic elastomer composition of the present invention, a dithiocarbamate antioxidant, a hindered phenol antioxidant, a sulfur antioxidant, a phosphorus antioxidant, etc. as an antioxidant. Can be blended.

  As the dithiocarbamate-based antioxidant, metal salts of dialkyl dithiocarbamic acids are preferable, among which nickel dialkyl dithiocarbamates are preferable, and in particular, nickel dibutyl dithiocarbamate is preferable because it has a large improvement effect on heat aging resistance.

Specific examples of hindered phenolic antioxidants include 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, hydroxy Methyl-2,6-di-t-butylphenol, 2,6-di-t-α-dimethylamino-p-cresol, 2,5-di-t-butyl-4-ethylphenol, 4,4'-bis (2,6-di-tert-butylphenol), 2,2'-methylene-bis-4-methyl-6-tert-butylphenol, 2,2'-methylene-bis (4-ethyl-6-tert-butylphenol) 4,4'-Methylene-bis (6-t-butyl-o-cresol), 4,4'-methylene-bis (2,6-di-t-butylphenol), 2,2'-methylene-bis (2 4-Methyl-6-cyclohexene (4) -Butylidene-bis (3-methyl-6-t-butylphenol), 4,4'-thiobis (6-t-butyl-3-methylphenol), bis (3-methyl-4) -Hydroxy-5-tert-butylbenzyl) sulfide, 4,4'-thiobis (6-tert-butyl-o-cresol), 2,2'-thiobis (4-methyl-6-tert-butylphenol), 2, 2, 3- 6-bis (2'-hydroxy-3'-t-butyl-5'-methylbenzyl) -4-methylphenol, 3,5-di-t-butyl-4-hydroxybenzenesulfonic acid diethyl ester, 2,2 '-Dihydroxy-3,3'-di (α-methylcyclohexyl) -5,5'-dimethyl-diphenylmethane, α-octadecyl-3 (3', 5'-di-t-butyl-4'-hydroxyphenyl) Propi , 6- (hydroxy-3,5-di-t-butylanilino) -2,4-bis-octyl-thio-1,3,5-triazine, hexamethylene glycol-bis [β- (3,5-di] -T-Butyl-4-hydroxyphenol) propionate], N, N'-hexamethylene-bis (3,5-di-t-butyl-4-hydroxyhydrocinnamic acid amide), 2,2-thio [diethyl- Bis-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 3,5-di-tert-butyl-4-hydroxybenzenephosphonic acid dioctadecyl ester, tetrakis [methylene-3 (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydride) Xybenzyl) benzene, 1,1,3-tris (2-methyl-4-hydroxy-5-di-t-butylphenyl) butane, tris (3,5-di-t-butyl-4-hydroxyphenyl) isocyanurate , Tris [β- (3,5-di-t-butyl-4hydroxyphenyl) propionyl-oxyethyl] isocyanurate and the like.
Among these, it is particularly preferable to use one having a molecular weight of 500 or more such as tetrakis [methylene-3 (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane.

  The sulfur-based antioxidants are sulfur-containing compounds such as thioethers, dithioacids, mercaptobenzimidazoles, thiocarbanilides, and thiodipropion esters. However, the thing equivalent to said dithiocarbamate-type antioxidant is not included. Among these, thiodipropion ester compounds are particularly preferable.

  Examples of phosphorus-based antioxidants include compounds containing phosphorus such as phosphoric acid, phosphorous acid, hypophosphorous acid derivatives, phenylphosphonic acid, polyphosphonates, dialkylpentaerythritol diphosphites, dialkyl bisphenol A diphosphites and the like.

  One of these antioxidants may be used alone, or two or more thereof may be used in combination.

  When the dynamically crosslinked thermoplastic elastomer composition of the present invention contains an antioxidant, the content of the antioxidant is preferably 0.01 per 100 parts by mass in total of the component (A) and the component (B). 5 parts by mass. If the content of the antioxidant is 0.01 parts by mass or more, it is preferable from the viewpoint of the improvement effect of the heat deterioration resistance, while if it is 5 parts by mass or less, problems such as bleeding are less likely to occur. It is preferable from the viewpoint of mechanical strength and the like.

  In addition, the dynamically crosslinked thermoplastic elastomer composition of the present invention preferably contains a colorant such as carbon black in order to improve the design and weatherability, and in this case, the colorant is a component (A). It is preferable to mix | blend 0.1-5 mass parts, especially 0.3-3 mass parts with respect to a total of 100 mass parts of B) and component (B). In addition, it is preferable to mix | blend trace amount components like coloring agents, such as carbon black, as a masterbatch of resin, such as polyolefin resin, from the surface of the uniform dispersibility in a thermoplastic-elastomer composition.

  In addition, the dynamically cross-linked thermoplastic elastomer composition of the present invention may contain a filler in order to improve production stability, dimensional stability and flame retardancy, and in this case, as the filler, glass is used. Fibers, hollow glass spheres, carbon fibers, talc, calcium carbonate, mica, potassium titanate fibers, silica, metal soaps, titanium dioxide, carbon black and the like can be mentioned (carbon black is used as a colorant and as a filler) Is possible). When mix | blending a filler, a filler is used with 0.1-200 mass parts normally with respect to a total of 100 mass parts of component (A) and component (B).

[Method for Producing Dynamically Crosslinkable Thermoplastic Elastomer Composition]
The dynamic crosslinkable thermoplastic elastomer composition of the present invention can be prepared by adding each of the components (A), (B), (C) and (D), other resin components, various additives, etc. It can be produced by mixing, kneading, or melt-kneading in a usual manner using an extruder, a Banbury mixer, a mixing roll, a roll, a Brabender plastograph, a kneader Brabender or the like. Among these, it is preferable to use an extruder, particularly a twin-screw extruder. When the dynamic crosslinkable thermoplastic elastomer composition of the present invention is kneaded and produced by an extruder or the like, it is preferable to melt and knead it while heating to a temperature of 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 or semi-molten state in the presence of the component (C). It is preferable to carry out this dynamic heat treatment by melt-kneading, and in the case of using a twin-screw extruder, each component is supplied to a raw material feed port (hopper) of a twin-screw extruder having a plurality of raw material feed ports. It is more preferable to carry out the heat treatment. Thus, a dynamic crosslinkable thermoplastic elastomer composition can be obtained by performing the dynamic heat treatment of melt-kneading in the presence of the component (C).

[Various physical properties]
The value of hardness Duro A (according to JIS K6253, hardness after 15 seconds) of the dynamically crosslinked thermoplastic elastomer composition of the present invention is 60 or less, preferably 58 or more and 30 or more. In addition, the measuring method of hardness Duro A is shown to the Example shown below.

  The value of the compression set (70 ° C. × 22 hours) of the dynamically crosslinkable thermoplastic elastomer composition of the present invention is preferably 38% or less. In addition, the measuring method of compression set is shown in the below-mentioned Example.

[Molded body]
The dynamically cross-linked thermoplastic elastomer composition of the present invention can be formed by any molding method used for conventional thermoplastic elastomer compositions, such as injection molding such as gas injection molding, injection compression molding, short shot foam molding, etc. It can be made into a molded object using various molding methods, such as a 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, when performing 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. In addition, secondary processing, such as lamination molding and thermoforming, can also be further performed to the obtained molded object after performing these shaping | molding.

  The dynamic crosslinkable thermoplastic elastomer composition of the present invention is suitable as a member for an automobile or a member for a building material, particularly as a sealing material for a vehicle or a sealing material for a building material, in order to exert the above-mentioned effects. Furthermore, the dynamically crosslinked thermoplastic elastomer composition of the present invention is an automotive component other than a sealing material for automobiles and sealing materials for construction materials (airbag storage cover, center panel, center console box, door trim, door trim, pillar, assist grip, steering , Weather strips, ceiling materials, interior sheets, bumper moldings, side moldings, air spoilers, air duct hoses, sealing materials, various packings, etc., civil engineering and building materials parts (water blocking materials, joint materials, window frames, window frame packings, Sealing materials, etc.) Sports goods (grips of golf clubs and tennis rackets), industrial parts (hose tubes, gaskets etc.), household electric parts (hose, packing etc), medical parts (medical containers, gaskets, Packing etc), food parts (containers, packing etc), medical equipment parts, electric wires, miscellaneous It can be used in a wide range of fields such as is particularly suitable as a molding material for automobile interior parts.

  EXAMPLES Hereinafter, the specific embodiments of the present invention will be described in more detail using examples, but the present invention is not limited by the following examples as long as the gist thereof is not exceeded. The values of various manufacturing 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 value of the upper limit or the lower limit described above The range defined by the values of the following examples or the combination of the values of the examples may be used.

  In the following Examples and Comparative Examples, the raw materials used for preparing the thermoplastic elastomer composition and the evaluation methods of the obtained thermoplastic elastomer composition are as follows.

<Raw materials>
Raw materials used in the following examples and comparative examples are as follows.

[Component (A)]
(A): a mixture of 100 parts by mass of the following ethylene / propylene • 5-ethylidene-2-norbornene copolymer (A-1) and 100 parts by mass of paraffinic oil (D-1) (A-1): ethylene · Propylene • 5-ethylidene-2-norbornene copolymer Ethylene content: 67% by mass
5-ethylidene-2-norbornene unit content: 4.5% by mass
Mooney viscosity of the mixture of (A-1) and (D-1) ML _{1 + 4} (125 ° C.): 64
(D-1): Softener for paraffin-based rubber (Paris oil based on Idemitsu Kosan Co., Ltd. Brand name: Diana (registered trademark) Process oil PW90)
Dynamic viscosity at 40 ° C: 95.54 cSt (centistokes)
Pour point: -15 ° C
Flash point: 272 ° C

[Component (B)]
(B-1): Modified polypropylene exhibiting strain hardening (manufactured by Nippon Polypropylene Corporation, trade name: WAYMAX MFX8)
MFR (230 ° C, 21.2 N): 1 g / 10 min Melt tension: 24 cN (230 ° C.)
Methylene carbon (Ca, Cb, Cc) and methine carbon (Cbr): Long-chain branching observed: 0.1 / 1000 total propylene (per 1000 total carbon atoms forming carbon)
Branching index g 'at an absolute molecular weight Mabs of 1,000,000: 0.89
(B-2): Modified polypropylene exhibiting strain curability (manufactured by Kaneka Corporation, Item No .: 047N)
MFR (230 ° C, load 21.2 N): 1.0 g / 10 min Melt tension: 8 cN (230 ° C)

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

[Component (D)]
(D-2): Softener for paraffin-based rubber (Paris oil based on Idemitsu Kosan Co., Ltd. Brand name: Diana (registered trademark) Process oil PW90)
Dynamic viscosity at 40 ° C: 95.54 cSt (centistokes)
Pour point: -15 ° C
Flash point: 272 ° C

[Component (E)]
(E-1): Polypropylene-based resin (Polypropylene homopolymer manufactured by Japan Polypropylene Corp. Product name: Novatec (registered trademark) PP FY6)
MFR (230 ° C., load 21.2 N): 2.5 g / 10 min Density (JIS K 7112: 1999): 0.90 g / cm ³
(E-2): Polypropylene-based resin (Ethylene-propylene copolymer manufactured by Nippon Polypropylene Corporation, trade name: Novatec (registered trademark) PP EG8B)
MFR (230 ° C., load 21.2 N): 0.8 g / 10 min Density (JIS K 7112: 1999): 0.90 g / cm ³
(E-3): polypropylene-based resin (polypropylene homopolymer manufactured by Japan Polypropylene Corporation, trade name: Novatec (registered trademark) PP EA9)
MFR (230 ° C., load 21.2 N): 0.5 g / 10 min Density (JIS K 7112: 1999): 0.90 g / cm ³

[Component (F)]
Filler (Talc brand name PHSH made by Takehara Chemical Industry Co., Ltd.)

[Component (G)]
Antioxidant (made by BASF Japan Ltd. trade name: Irganox (registered trademark) 1010)
[Component (H)]
Antioxidant (made by BASF Japan Ltd. trade name: Irganox (registered trademark) FS301FF)
[Component (I)]
Black pigment (Dainichi Seika Kogyo Co., Ltd. trade name: PC40C carbon concentration 40% by mass, low density polyethylene 60% by mass)

<Evaluation method>
Various evaluation methods of the dynamically crosslinked thermoplastic elastomer composition in Examples and Comparative Examples are shown below. In the following measurements (2) to (4), an injection pressure of 50 MPa, a cylinder temperature of 220 ° C., a mold temperature of 40 ° C., using an in-line screw type injection molding machine (product name: IS130, manufactured by Toshiba Machine Co., Ltd.) Each thermoplastic elastomer composition was injection-molded under the following conditions to form a sheet 2 mm thick × 120 mm wide × 80 mm long. In the following (4) compression set, 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 29 mmφ are stacked to obtain a test piece It produced and measured using this test piece.

(1) Extruded appearance A sheet of 0.5 mm thick × 35 mm wide obtained at a cylinder setting temperature of 160 ° C. to 200 ° C. and a rotation speed of 20 rpm using a single-screw extruder with a bore of 20 mm and a full flight screw The surface, the smoothness of the end portion, and the presence or absence of the edge were observed and judged based on the following criteria.
○: good △: somewhat bad ×: bad

(2) Injection appearance As described above, the appearance of the 2 mm thick × 120 mm wide × 80 mm long sheet obtained by injection molding was visually observed, and the flow mark and the transfer unevenness were judged based on the following criteria.
○: good △: somewhat bad ×: bad

(3) Hardness Duro A
The hardness (after 15 seconds) was measured in accordance with JIS K6253 (Duro-A).

(4) Compression set: Measured under conditions of 70 ° C., 22 hours, 25% compression in accordance with the standard of JIS K6262.

Example 1
Each raw material other than (D-2) was mix | blended as Table 1, and it mixed for 1 minute with the Henschel mixer. Subsequently, the obtained mixture is introduced by a mass feeder into the upstream feed port of a co-directional twin screw extruder (manufactured by Japan Steel Works, Ltd., product number: TEX 30, L / D = 46, number of cylinder blocks: 12) did. Then, the component (D-2) is supplied from the supply port in the middle of the extruder by a liquid addition pump, and the temperature is raised in the range of 160 to 200 ° C. from the upstream portion to the discharge amount of 20 kg / h in total. The mixture was melt-kneaded and pelletized to produce the dynamically crosslinked thermoplastic elastomer composition of Example 1. Various physical properties of the obtained dynamically crosslinked thermoplastic elastomer composition of Example 1 are shown in Table 1.
In addition, in Table 1, the compounding quantity of (C-1) shows the compounding quantity of only 2, 5- dimethyl- 2, 5- di (t- butylperoxy) hexane except calcium carbonate.

[Examples 2 and 3 and Comparative Examples 1 to 7]
It processed similarly to Example 1 except changing to the composition shown in Table 1, and obtained the pellet of the dynamically crosslinked thermoplastic elastomer composition of Example 2, 3 and Comparative Example 1-7, respectively. The various physical properties of each are shown in Table 1.

[Evaluation results]
As shown in Table 1, Examples 1 to 3 corresponding to the dynamically cross-linked thermoplastic elastomer composition of the present invention all have low hardness and good injection appearance, extrusion appearance and compression set characteristics. I understand.
On the other hand, in the dynamically crosslinked thermoplastic elastomer composition of the comparative example, any of the hardness, the extrusion appearance, the injection appearance or the compression set property was insufficient.
From these results, it was found that the dynamically crosslinked thermoplastic elastomer composition of the present invention containing the component (B) has low hardness and good injection, extrudability, and sealing properties.

Claims (5)

Containing component (B) at a content of 70 to 90 parts by mass of component (A) in the total 100 parts by mass of component (A) and component (B) containing the following components (A) to (D) The content of component (D) is 10 to 30 parts by mass, and the content of component (C) is 0.05 to 20 parts by mass with respect to a total of 100 parts by mass of component (A) and component (B) Dynamically crosslinkable thermoplastic elastomer composition having a Duro A hardness of 60 or less according to JIS K6253.
Component (A): Ethylene / α-olefin / nonconjugated diene copolymer rubber Component (B): Melt flow rate (230 ° C., load 21.2 N, in accordance with JIS K 7210) for 0.1 to 250 g / 10 min, and Strain-curable modified polypropylene having a melt tension of 1.0 to 20 cN Component (C): Crosslinking agent Component (D): Softener for hydrocarbon rubber   The dynamically crosslinked thermoplastic elastomer composition according to claim 1, wherein the component (B) is a strain-curable modified polypropylene having a long chain branched structure.   The component (C) is at least one selected from the group consisting of an organic peroxide, a phenol resin, a silicon hydride compound, a polyfunctional vinyl compound, a polyfunctional (meth) acrylate compound, and tin chloride. The dynamically crosslinked thermoplastic elastomer composition as described in 1 or 2.   The dynamically crosslinked thermoplastic elastomer composition according to claim 3, wherein the component (C) is an organic peroxide.   The molded object which consists of a dynamically crosslinked-type thermoplastic-elastomer composition of any one of Claims 1-4.