JP6834261B2 - Thermoplastic elastomer composition - Google Patents

Description

The present invention relates to thermoplastic elastomer compositions. More specifically, the present invention relates to a thermoplastic elastomer composition having an excellent balance between rubber elasticity and fluidity.

A thermoplastic elastomer is an elastomer that softens by heating and has fluidity, and when cooled, it has rubber elasticity. Specifically, during molding, it melts at the processing temperature and can be easily molded in the same manner as a well-known thermoplastic resin. However, after molding, the temperature actually used as various materials is used. In the above, it has the same physical properties as the crosslinked rubber. As described above, the thermoplastic elastomer has the same molding processability as the thermoplastic resin, has unique rubber elasticity, and is recyclable. Therefore, automobile parts, building parts, medical parts, and the like. It is widely used for wire coating materials, miscellaneous goods, etc.

As a typical example of a thermoplastic elastomer composition, a dynamically crosslinked thermoplastic elastomer (TPV) composition is known. The dynamically crosslinked thermoplastic elastomer composition is characterized by a sea-island structure in which crosslinked rubber particles, which are thermosetting elastomers, are finely dispersed as domains (island phases) in a crystalline thermoplastic matrix (sea phase). It is a polyphase polymer material. At room temperature, the domain imparts the function of vulcanized rubber to the TPV composition, and at high temperature, the thermoplastic matrix flows and plastic deformation is possible, so that the same molding process as that of thermoplastic plastic is possible. These materials are used in many applications where vulcanized rubber is used, such as hoses, gaskets and the like.

The TPV composition is typically cross-linked by reacting a cross-linking elastomer containing a diene or the like with a suitable cross-linking agent to achieve dynamic cross-linking, that is, cross-linking while mixing inside a mixer, molding machine or the like. It is obtained by forming crosslinked rubber particles while finely dispersing in the thermoplastic matrix.

Most of the TPV compositions obtained by dynamically heat-treating an ethylene / α-olefin / non-conjugated diene copolymer and a polyolefin resin in the presence of a cross-linking agent have been put into practical use, and the amount of diene has been reduced. Studies have been conducted to increase the degree of cross-linking and improve rubber elasticity by increasing the amount of cross-linking agent, increasing the amount of cross-linking agent, and increasing the cross-linking reaction time. However, since the fluidity decreases when the rubber elasticity is increased, it has been an issue to achieve both the rubber elasticity and the fluidity.

Patent Documents 1 and 2 are derived from a main chain composed of an ethylene / α-olefin copolymer or an ethylene / α-olefin / non-conjugated diene copolymer and a crystalline propylene polymer containing a vinyl group at one end. A thermoplastic elastomer composition containing a branched olefin-based copolymer having a side chain is proposed. In these thermoplastic elastomer compositions, a side chain of a highly crystalline polypropylene segment and a main chain of an ethylene / α-olefin copolymer or an ethylene / α-olefin / non-conjugated diene copolymer are used as a thermoplastic elastomer. Although it is said that extremely high performance can be obtained, even in the thermoplastic elastomer compositions described in Patent Documents 1 and 2, both rubber elasticity and fluidity cannot be sufficiently satisfied.

Japanese Patent No. 5600219 Japanese Unexamined Patent Publication No. 2014-214204

An object of the present invention is to provide a thermoplastic elastomer composition having an excellent balance between rubber elasticity and fluidity.

As a result of studies by the present inventor to solve the above problems, a polyolefin (a) having a reactive functional group at least at one end, an ethylene / α-olefin / non-conjugated diene copolymer (b), and a polyolefin resin (c) It has been found that a thermoplastic elastomer composition containing) can solve the above-mentioned problems. That is, the gist of the present invention is as follows [1] to [8].

[1] Polyolefin (a) having a reactive functional group at least at one end, ethylene / α-olefin / non-conjugated diene copolymer (b), and polyolefin resin (c) (however, the component (a) is different. ) And at least a thermoplastic elastomer composition.

[2] 0.1 to 400 parts by mass of polyolefin (a) having a reactive functional group at least at one end with respect to 100 parts by mass of ethylene / α-olefin / non-conjugated diene copolymer (b), polyolefin resin The thermoplastic elastomer composition according to [1], which contains 0.1 to 400 parts by mass of (c).

[3] The thermoplastic elastomer composition according to [1] or [2], which further contains a cross-linking agent (d) and / or a hydrocarbon-based rubber softening agent (e).

[4] The thermoplastic elastomer composition according to [3], which contains a catalyst (f) together with a cross-linking agent (d).

[5] The thermoplastic elastomer composition according to [4], which contains a neutralizing agent (g) together with a cross-linking agent (d) and a catalyst (f).

[6] The thermoplastic elastomer composition according to any one of [1] to [5], wherein the polyolefin (a) having at least one terminal having a reactive functional group is a propylene polymer having a vinyl group at one end.

[7] The thermoplastic elastomer composition according to any one of [1] to [6], wherein the polyolefin resin (c) is a polypropylene resin having a number average molecular weight of 50,000 or more and 250,000 or less.

[8] The melt flow rate (MFR) measured under the conditions of 230 ° C. and a load of 49 N according to JIS K7210 is 5 to 200 g / 10 minutes, and 70 ° C., 22 hours, 25% compression according to JIS K6262. The thermoplastic elastomer composition according to any one of [1] to [7], which has a compression set of 60% or less measured under the conditions of.

The thermoplastic elastomer composition of the present invention has an excellent balance between rubber elasticity and fluidity. Therefore, the thermoplastic elastomer composition of the present invention is industrially very useful as a substitute material for crosslinked rubber having excellent molding processability.

The thermoplastic elastomer composition of the present invention can be suitably used in the automobile field such as seals, cushions and boots; the construction field such as gaskets and packing; and the miscellaneous goods field such as grips and casters.

Hereinafter, embodiments of the present invention will be described in detail, but the following description is typical examples of embodiments of the present invention, and the present invention is not limited to these contents. In the present invention, "~" is used to mean that the numerical values described before and after the value are included as the lower limit value and the upper limit value.

[Thermoplastic Elastomer Composition]
The thermoplastic elastomer composition of the present invention comprises a polyolefin (a) having a reactive functional group at least at one end (hereinafter, may be referred to as “component (a)”) and ethylene / α-olefin / non-conjugated. The diene copolymer (b) (hereinafter, may be referred to as "component (b)") and the polyolefin resin (c) different from the component (a) may be referred to as "component (c)". There is.) And as an essential ingredient.
The thermoplastic elastomer composition of the present invention preferably further contains a cross-linking agent (d) (hereinafter, may be referred to as "component (d)") and a hydrocarbon-based rubber softening agent (e) (hereinafter, referred to as "component (d)"). It may be referred to as "component (e)"), catalyst (f) (hereinafter, may be referred to as "component (f)"), neutralizer (g) (hereinafter, "component (g)"). It may be referred to as), and if necessary, it may contain other components other than the components (a) to (g) as long as the effects of the present invention are not impaired. ..

<Working mechanism>
The thermoplastic elastomer composition of the present invention containing a polyolefin (a) having a reactive functional group at least at one end, an ethylene / α-olefin / non-conjugated diene copolymer (b), and a polyolefin resin (c) The details of the mechanism of action that can achieve both rubber elasticity and fluidity to be excellent are not clear, but are presumed as follows.

In preparing the thermoplastic elastomer composition, when the polyolefin (a) having a reactive functional group at least at one end, the ethylene / α-olefin / non-conjugated diene copolymer (b) and the polyolefin resin (c) are kneaded, It is presumed that the following reactions (I) to (III) occur.
(I) Crosslinking reaction of ethylene / α-olefin / non-conjugated diene copolymer (b) (II) Ethylene / α-olefin / non-conjugated diene copolymer of polyolefin (a) having a reactive functional group at least at one end Copolymerization reaction to coalescence (b) (Component (b) is grafted to component (a), and component (b) forms a graft chain to the main chain of component (a).)
(III) Bonding reaction between polyolefins (a) having a reactive functional group at least at one end Of these, the grafted product produced by the reaction of (II) above is the crystallinity of a conventional dynamically crosslinked thermoplastic elastomer. Compatibility between the polyolefin resin (c) phase corresponding to the thermoplastic matrix (sea phase) and the ethylene / α-olefin / non-conjugated diene copolymer (b) phase corresponding to the domain (island phase) of the crosslinked rubber particles. It is considered that by functioning as an agent, sufficient fluidity is imparted while maintaining rubber elasticity.

The thermoplastic elastomer composition described in Patent Document 2 described above includes a main chain composed of an ethylene / α-olefin / diene copolymer corresponding to the component (b) used in the present invention and a component used in the present invention. It contains a branched structure olefin copolymer having a side chain derived from a crystalline propylene polymer (crystalline polypropylene macromonomer) having a vinyl group at one end corresponding to (a), and is described in Patent Document 2. Describes that the thermoplastic elastomer composition may be dynamically crosslinked in the presence of a crosslinking agent, and for the purpose of improving various physical properties of the elastomer, other elastomer components such as diene copolymer rubber, There is also a description that a crystalline resin component such as a crystalline polyolefin may be added.
The branched structure olefin copolymer in Patent Document 2 is a mixture of a crystalline propylene polymer having a vinyl group at one end, ethylene, α-olefin and diene, and is coordinated in the presence of a specific transition metal catalyst. It is produced by polymerization, and in the composition after polymerization, not only the branched structure olefin copolymer of the product but also the ethylene / α-olefin / diene copolymer and the crystalline polypropylene macromonomer are included. It will be included.

However, Patent Document 2 does not provide an example in which a polyolefin resin is specifically blended, and the type and blending amount of the polyolefin resin to be used have not been examined at all.
In the present invention, the polyolefin resin (c) is contained as an essential component to improve the fluidity and achieve both rubber elasticity and fluidity. However, Patent Document 2 does not include a description suggesting such an effect. Absent.
Moreover, a crystalline propylene polymer having a vinyl group at one end is mixed with ethylene, α-olefin and non-conjugated diene, and coordinated polymerization in the presence of a specific transition metal catalyst to carry out coordinate polymerization of the branched structure olefin. When a coalescence is produced, it is presumed that the cross-linking reaction of the ethylene / α-olefin / non-conjugated diene copolymer does not proceed at the same time, and the polyolefin (a) having a reactive functional group at least at one end, the ethylene / α-olefin, The thermoplastic elastomer composition of the present invention containing the non-conjugated diene copolymer (b) and the polyolefin resin (c), or the polyolefin (a) having a reactive functional group at least at one end, ethylene / α-olefin / non-conjugated. Like the thermoplastic elastomer composition of the present invention obtained by dynamically heat-treating a mixture containing the diene copolymer (b) and the polyolefin resin (c), the effect of improving the rubber elasticity derived from the crosslinked structure can be obtained. Absent.

<Polyolefin (a) having a reactive functional group at least at one end>
Examples of the reactive functional group of the polyolefin (a) having a reactive functional group at least one end include a vinyl group, an alkynyl group, a hydroxy group, an amino group, a nitro group, a mercapto group, a sulfo group, a cyano group, a carbonyl group and an imino. Groups, halogen groups and the like can be mentioned. Of these, the component (a) preferably has a vinyl group as the reactive functional group from the viewpoint of reactivity with the diene in the ethylene / α-olefin / non-conjugated diene copolymer. The component (a) may contain only one of these reactive functional groups, or may contain two or more of these reactive functional groups.

The polyolefin of the component (a) includes a propylene resin, an ethylene resin, a crystalline polybutene-1 resin, an ethylene-vinyl acetate copolymer, an ethylene- (meth) acrylic acid copolymer, and an ethylene- (meth). Ethylene-based copolymer resins such as acrylic ester copolymers can be mentioned, but propylene-based resins are preferable from the viewpoint of improving heat resistance and moldability.

In particular, the component (a) is a crystalline propylene polymer having a vinyl group at one end from the viewpoint of reactivity with diene in an ethylene / α-olefin / non-conjugated diene copolymer, heat resistance and moldability. (Hereinafter, it may be referred to as "crystalline polypropylene macromonomer".).

Hereinafter, a crystalline polypropylene macromonomer suitable as the component (a) will be described.

The terminal vinyl group of the crystalline polypropylene macromonomer is an unsaturated bond formed at the terminal due to β-hydrogen desorption or β-methyl desorption at the terminal end of propylene polymerization, and the resulting unsaturated bond is formed. It means that three of the four substituents are hydrogen atoms. This terminal vinyl group is also called a 1-propenyl group. Usually, unsaturated terminals other than this vinyl group, such as vinylidene group and internal olefin, are difficult to carry out the above-mentioned grafting reaction, so it is important that the terminal group of the crystalline polypropylene macromonomer is a vinyl group.

Preferred examples of the crystalline polypropylene macromonomer used in the present invention include the following (a1) or (a2).
(A1) A crystalline propylene polymer having a vinyl group at one end, an isotactic pentad fraction of 0.80 or more, and a number average molecular weight (Mn) of 75,000 or less (hereinafter, "" It may be referred to as "component (a1)".)
(A2) A crystalline propylene polymer having a vinyl group at one end, a syndiotactic pentad fraction of 0.60 or more, and a number average molecular weight (Mn) of 75,000 or less (hereinafter, "" It may be referred to as "component (a2)".)

The method for producing the component (a1) or the component (a2) is not particularly limited, and a conventionally known method for producing a macromonomer can be appropriately used, but a highly crystalline polypropylene macromonomer can be efficiently used. A manufacturable method is preferred. More specifically, a method produced by coordinate polymerization of propylene using a transition metal compound and having a vinyl group at a high proportion of the polymerization-terminated ends is preferable from an economical point of view.

For example, as a method for producing the component (a1), a stereorigid C2 symmetric crosslinked metallocene catalyst is used, and the β-methyl group elimination reaction frequently occurs by polymerizing propylene at a high temperature, and vinyl at the terminal is used. A method of introducing a group (for example, JP-A-2001-525461), by using a complex having a bulky substituent at a specific site, or by using a complex having a heterocyclic group at a specific site, relatively. Method for producing while maintaining high stereoregularity by increasing the frequency of β-methyl elimination reaction at low temperature (for example, JP-A-11-349634, JP-A-2009-299045, etc.), isotactic structure selective A method of copolymerizing a vinyl comonomer having a functional group that is easily desorbed, such as vinyl chloride, in propylene using a metallocene catalyst, and causing β-functional group desorption at the same time when this comonomer is inserted to selectively produce a macromonomer having a terminal vinyl group. (Gaynor, SG Macromonomers 2003, 36, 4692-4689) and propylene polymerization catalysts in which 2,1-insertion of propylene is prioritized (for example, late-period transition metals such as pyridyldiimine iron (II) complexes. A method of introducing a terminal vinyl group through β-hydrogen desorption using a complex) without going through a relatively difficult β-methyl group desorption process (Blockart, M. et. Al. Monomercules 1999, 32, 2120) and the like can be mentioned.

Among these, a method for producing while maintaining high stereoregularity by increasing the frequency of β-methyl elimination reaction at a relatively low temperature by using a complex having a heterocyclic group at a specific site (for example, JP-A-2009-). 299045) is particularly preferable from the viewpoint of achieving both high stereoregularity and high vinyl selectivity.

As a method for producing the component (a2), a method using a non-bridged metallocene catalyst having a very bulky substituent (Resconi, L. et. Al. J. Am. Chem. Soc. 1992, 114, 1025.) , A method of polymerizing propylene at high temperature using a stereorigid Cs symmetric crosslinked metallocene catalyst (Japanese Patent Laid-Open No. 2001-525461), having a functional group such as vinyl chloride that is easily desorbed in propylene by a syndiotactic selective metallocene catalyst. A method of copolymerizing a vinyl comonomer and causing β-functional group elimination at the same time as the vinyl comonomer is inserted to selectively produce a macromonomer having a terminal vinyl group (Kaminsky, W. et. Al. Macromol. Chem. Phys. 2010, ASAP), a bis (phenoxyimine) titanium complex with a specific substituent, selectively introduces a vinyl group at the end of the syndiotactic polypropylene by β-hydrogen desorption from the 2,1-insertion of propylene. Methods (International Publication No. 03/025025, or Cherian, AE et. Al, Macromethylules 2005, 38, 6268, etc.) and the like can be mentioned.

Of these, from the viewpoint of achieving both high stereoregularity and high vinyl selectivity, syndiotac was used by using a bis (phenoxyimine) titanium complex having a specific substituent and by β-hydrogen elimination from 2,1-insertion of propylene. A method in which a vinyl group is selectively introduced at the end of the tic polypropylene is preferable.

The crystalline polypropylene macromonomer usually has a vinyl group at one end, but may contain a molecule having no vinyl group at the end, or may contain a molecule having a vinyl group at both ends. Preferably, one end of the macromonomer molecule is a vinyl group and the other end is an alkyl group.

The method for producing the crystalline polypropylene macromonomer used in the present invention is not limited, but as described above, it is preferably produced by coordination polymerization of propylene from an economical point of view. This is because, when produced by this method, the terminal of the crystalline polypropylene macromonomer molecule usually has an alkyl group at the start end of the polymerization reaction and a vinyl group at the end end of the polymerization reaction. In this case, the possibility that both ends of the macromonomer molecule will be vinyl groups is usually extremely low.

The ratio of molecules having a vinyl group at one end (terminal vinyl ratio) to the obtained crystalline polypropylene macromonomer is usually 50% or more, preferably 80% or more. If this ratio is less than 50%, the ratio of crystalline polypropylene macromonomers contained in the thermoplastic elastomer composition of the present invention to be grafted is small, and the performance of the obtained thermoplastic elastomer composition becomes insufficient. There is a risk.

The terminal vinyl ratio of the polypropylene macromonomer is ^{determined from the measurement results of 13} C-NMR and ¹ H-NMR based on the following formula.
Terminal vinyl ratio (%) = number of vinyl terminals / number of starting terminals
= Number of vinyl terminals / {(number of total terminals-number of long chain branches) / 2}
Total number of terminals = number of i-butyl terminals + number of n-propyl terminals + number of n-butyl terminals + 2,3-dimethylbutyl terminal number + vinyl terminal number + vinylidene terminal number + vinylidene terminal number ( ^{determined from 13} C-NMR measurement)
Number of isobutyl terminals (pieces / 1000 propylene monomer)
= 1000 × (average of integrated values of signals of 22.52, 23.79, 25.76, 47.42 ppm) / integrated value of Sαα number of n-propyl terminals (pieces / 1000 propylene monomer)
= 1000 × (average of integrated values of signals of 14.47, 30.48, 39.64 ppm) / integrated value of Sαα n-butyl terminal number (pieces / 1000 propylene monomer)
= 1000 × (average of integrated values of signals of 14.11, 23.21, 36.90 ppm) / integrated value of Sαα 2,3-dimethylbutyl terminal number (pieces / 1000 propylene monomer)
= 1000 × (average of integrated values of signals of 16.23, 17.66, 36.42, 42.99 ppm) / integrated value of Sαα Number of long chain branches (pieces / 1000 propylene monomer)
= 1000 × (total of integrated values of signals of 31.60, 44.00, 44.69 ppm) / integrated value of (4 × Sαα) (obtained from ^{1 1} H-NMR measurement)
Number of vinyl terminals (pieces / 1000 propylene monomer)
= 2000 × (Integral value of vinyl signal in 4.9-5.1, 5.7-5.9 ppm region) / (Integral value of signal derived from main chain in 3.0-0.2 ppm region)
Number of vinylidene terminals (pieces / 1000 propylene monomer)
= 3000 × (Integral value of vinylidene signal of 4.69, 4.74 ppm) / (Integral value of signal derived from main chain in 3.0-0.2 ppm region)
Number of vinylene terminals (pieces / 1000 propylene monomer)
= 3000 × (Integral value of vinylene signal in 5.3-5.5 ppm region) / (Integral value of signal derived from main chain in 3.0-0.2 ppm region)

In order to satisfy the above characteristics, the crystalline polypropylene macromonomer is produced under appropriate polymerization conditions using an appropriate catalyst such as the above-mentioned production method.

Further, the crystalline polypropylene macromonomer may be a branched crystalline polypropylene macromonomer having crystalline polypropylene in the side chain as long as the rigidity and heat resistance are not impaired.

The structure of the crystalline polypropylene macromonomer is not particularly limited, but specifically, the polypropylene in the macromonomer has a structure having high stereoregularity. "Pentad (partsper)" is used as a factor indicating the high degree of stereoregularity of polypropylene. Pentad indicates the continuity of the relative arrangement of adjacent side chain methyl groups in polypropylene, and the higher this value, the higher the stereoregularity. The isotactic pentad fraction (mm mm) is the percentage of the propylene unit at the center of the chain in which five propylene monomer units are continuously mesobonded to the total propylene unit. The syndiotactic pentad fraction (rrrr) is the percentage of the propylene unit at the center of the chain in which five propylene monomer units are continuously lasemi-bonded to the total propylene unit. Pentad is usually ^{determined by 13} C-NMR. Specifically, it is obtained by the method described in JP-A-2003-292700. The polypropylene macromonomer used in the present invention preferably has a high isotactic pentad fraction (mm mm) or a syndiotactic pentad fraction (rrrr). This is because these are considered to give excellent elastomeric performance by forming stronger crystals with a high degree of crystallinity as "hard segments", which act as stronger cross-linking points.

As a crystalline polypropylene macromonomer having a high isotactic pentad fraction (hereinafter, may be referred to as "isotactic polypropylene macromonomer"), the isotactic pentad fraction (mm mm) is usually 0.80. As mentioned above, it is preferably 0.90 or more. The larger the isotactic pentad fraction is, the higher the melting point is, which is preferable in that the heat resistance is further improved. The upper limit is not particularly limited as long as the object of the present invention is not impaired, but the upper limit is usually 1.00, which is a calculated upper limit.

As a polypropylene macromonomer having a high syndiotactic pentad fraction (hereinafter, may be referred to as "syndiotactic polypropylene macromonomer"), the syndiotactic pentad fraction (rrrr) is usually 0.60 or more. Yes, preferably 0.70 or more, more preferably 0.80 or more, still more preferably 0.90 or more. The larger the syndiotactic pentad fraction, the higher the melting point and the higher the heat resistance, which is preferable. The upper limit is not particularly limited as long as the object of the present invention is not impaired, but the upper limit is usually 1.00, which is a calculated upper limit.

The crystalline polypropylene macromonomer may contain a unit derived from ethylene or an α-olefin other than propylene. A small amount of heterogeneous bonds that can be introduced in the process of polymerizing polypropylene and a small amount of comonomer to compensate for the solubility during polymerization are acceptable as long as they do not significantly impair the rigidity and heat resistance of the side chains. However, in terms of maintaining rigidity and heat resistance, the crystalline polypropylene macromonomer is preferably a homopolymer of propylene.

The crystalline polypropylene macromonomer usually has a melting point of 60 ° C. or higher, preferably 80 ° C. or higher, more preferably 100 ° C. or higher, still more preferably 120 ° C. or higher. The melting point can be defined by differential thermal analysis (DSC) and can be used as an indicator of the crystallinity of the crystalline polypropylene macromonomer. Amorphous or low crystallinity polypropylene macromonomers cannot act as hard segments capable of forming physical cross-linking points, and even if they exist as the above-mentioned graft chains, their performance as elastomers is not expected.

The molecular weight of the crystalline polypropylene macromonomer used in the present invention is not particularly limited, but can be arbitrarily adjusted to obtain a composition having the desired physical and mechanical properties.

The molecular weight of the crystalline polypropylene macromonomer is determined by GPC measurement. The number average molecular weight (Mn) of the crystalline polypropylene macromonomer is usually 200,000 or less, preferably 100,000 or less, and more preferably 75,000 or less from the viewpoint of fluidity. On the other hand, the number average molecular weight (Mn) of the crystalline polypropylene macromonomer is usually 1,000 or more, preferably 3,000 or more, and more preferably 10,000 or more from the viewpoint of improving moldability and physical properties. ..

The molecular weight distribution (mass average molecular weight (Mw) / number average molecular weight (Mn)) of the crystalline polypropylene macromonomer used in the present invention is not particularly limited, but in order to enable precise control of physical properties by the molecular weight, crystalline polypropylene The molecular weight distribution of the macromonomer is preferably as narrow as possible. The Mw / Mn is usually 1 or more, 6 or less, preferably 3 or less.

The number average molecular weight (Mn) of the crystalline polypropylene macromonomer is measured by the method described in the section of Examples described later.

The thermoplastic elastomer composition of the present invention may contain only one type of polyolefin (a) having a reactive functional group at least at one end, such as a crystalline polypropylene macromonomer, and may contain two or more types. It may be.

<Ethylene / α-olefin / non-conjugated diene copolymer (b)>
The α-olefin unit in the ethylene / α-olefin / non-conjugated diene copolymer (b) includes propylene unit, 1-butene unit, 3-methyl-1-butene unit, 1-pentene unit, and 4-methyl-1. -Pentene unit, 1-hexene unit, 4-methyl-1-hexene unit, 1-hexene unit, 1-octene unit, 1-decene unit and the like can be mentioned. Among these, propylene unit, 1-butene unit and 1-hexene unit are preferable, and propylene unit is particularly preferable. The ethylene / α-olefin / non-conjugated diene copolymer (b) may contain only one of these α-olefin units, or may contain two or more of them.

The non-conjugated diene unit in the ethylene / α-olefin / non-conjugated diene copolymer (b) includes a dicyclopentadiene unit, a 1,4-hexadiene unit, a cyclooctadiene unit, a methylenenorbornene unit, an ethylidene norbornene unit, and a vinylidene norbornene. Units and the like can be mentioned. Among these, it is preferable that the ethylidene norbornene unit and / or the vinylidene norbornene unit is contained because an appropriate crosslinked structure can be given to the ethylene / α-olefin / unconjugated diene copolymer (b). The ethylene / α-olefin / non-conjugated diene copolymer (b) may contain only one of these non-conjugated diene units, or may contain two or more of them.

The content of ethylene units in the ethylene / α-olefin / non-conjugated diene copolymer (b) is based on the total amount of the monomer units constituting the ethylene / α-olefin / non-conjugated diene copolymer (b). It is preferably 50% by mass or more, more preferably 55% by mass or more, while preferably 90% by mass or less, and more preferably 80% by mass or less. It is preferable that the content of ethylene units is in the above range in order to provide appropriate flexibility.

The content of the α-olefin unit in the ethylene / α-olefin / non-conjugated diene copolymer (b) is the monomer unit constituting the ethylene / α-olefin / non-conjugated diene copolymer (b). It is preferably 10% by mass or more, more preferably 20% by mass or more, and preferably 45% by mass or less, more preferably 35% by mass or less, based on the total amount. It is preferable that the content of the α-olefin unit is in the above range in order to give appropriate flexibility.

Further, the content of the non-conjugated diene unit in the ethylene / α-olefin / non-conjugated diene copolymer (b) is the monomer unit constituting the ethylene / α-olefin / non-conjugated diene copolymer (b). With respect to the total amount, it is preferably 1% by mass or more, preferably 3% by mass or more, while preferably 10% by mass or less, preferably 8% by mass or less. When the content of the non-conjugated diene unit is at least the above lower limit value, it is preferable from the viewpoint of increasing the degree of cross-linking of the thermoplastic elastomer composition, and when it is at least the above upper limit value, it is preferable from the viewpoint of moldability.

The content of each structural unit in the ethylene / α-olefin / non-conjugated diene copolymer (b) can be determined by infrared spectroscopy.

The mass average molecular weight (Mw) of the ethylene / α-olefin / non-conjugated diene copolymer (b) is preferably 300,000 or more, more preferably 350,000 or more, still more preferably 400,000 or more. Is. The mass average molecular weight (Mw) of the ethylene / α-olefin / non-conjugated diene copolymer (b) is preferably 1,000,000 or less, more preferably 900,000 or less, still more preferably 900,000 or less. It is 800,000 or less. When the mass average molecular weight (Mw) of the ethylene / α-olefin / non-conjugated diene copolymer (b) is not more than the above upper limit value, it is preferable from the viewpoint of appearance, and when it is more than the above lower limit value, from the viewpoint of improving rubber elasticity, bleeding. It is preferable from the viewpoint of preventing out.

The method and conditions for measuring the mass average molecular weight (Mw) of the ethylene / α-olefin / non-conjugated diene copolymer (b) are as shown in the section of Examples below.

The thermoplastic elastomer composition of the present invention may contain only one of ethylene, α-olefin, and non-conjugated diene copolymer (b), and the monomer unit contained therein, its content, and physical properties. It may contain two or more different types such as.

<Polyolefin resin (c)>
Examples of the polyolefin resin (c) (however, different from the component (a)) include a propylene resin, an ethylene resin, a crystalline polybutene-1 resin, an ethylene-vinyl acetate copolymer, and an ethylene- (meth) acrylic acid copolymer. Examples thereof include ethylene-based copolymer resins such as coalesced and ethylene- (meth) acrylic acid ester copolymers, but propylene-based resins are preferably used because they are excellent in heat resistance, molding processability, and the like.

The polypropylene-based resin is a polyolefin resin in which the content of propylene units with respect to all monomer units is more than 50% by mass.

The type of polypropylene-based resin is not particularly limited, and any of propylene homopolymer, propylene random copolymer, propylene block copolymer and the like can be used.

When the polypropylene-based resin is a propylene random copolymer, the monomers copolymerizing with propylene include ethylene, 1-butene, 2-methylpropylene, 1-pentene, 3-methyl-1-butene, and 1-hexene. , 4-Methyl-1-pentene, 1-octene and the like can be exemplified. When the polypropylene-based resin is a propylene block copolymer, a propylene block copolymer obtained by polymerizing in multiple steps can be mentioned. More specifically, polypropylene is polymerized in the first step and then in the second step. Examples thereof include propylene block copolymers obtained by polymerizing propylene / ethylene copolymers.

The content of the propylene unit in the polypropylene-based resin is preferably 60% by mass or more, more preferably 75% by mass or more, and further preferably 90% by mass or more. When the content of the propylene unit is at least the above lower limit value, the heat resistance and the rigidity tend to be good. On the other hand, the upper limit of the content of the propylene unit in the polypropylene-based resin is not particularly limited and is usually 100% by mass. The content of propylene units in the polypropylene resin can be determined by infrared spectroscopy.

The number average molecular weight (Mn) of the polypropylene-based resin is usually 250,000 or less, and preferably 200,000 or less from the viewpoint of fluidity. On the other hand, the number average molecular weight (Mn) of the polypropylene resin is usually 50,000 or more, and is preferably 60,000 or more from the viewpoint of moldability and heat resistance.

The number average molecular weight (Mn) of the polypropylene-based resin is measured by the method described in the section of Examples described later.

As a method for producing the polypropylene-based resin, a known polymerization method using a known catalyst for olefin polymerization is used. For example, a multi-stage polymerization method using a Ziegler-Natta catalyst can be mentioned. For this multi-stage polymerization method, a slurry polymerization method, a solution polymerization method, a massive polymerization method, a gas phase polymerization method and the like can be used, and two or more of these may be combined for production.

In addition, it is also possible to use a commercially available applicable polypropylene resin. As a commercially available polypropylene-based resin, it can be procured from the following manufacturers and the like, and can be appropriately selected. Available commercially available products include Novatec (registered trademark) PP from Japan Polypropylene Corporation, Prime Polypro (registered trademark) from Prime Polymer Co., Ltd., Sumitomo Noblen (registered trademark) from Sumitomo Chemical Co., Ltd., Polypropylene block copolymer from Sun Aroma Co., Ltd., Lyondell Basell Co., Ltd. (Registered Trademarks), ExxonMobil's ExxonMobil PP, Formosa Plastics'Formolene (Registered Trademarks), Borearis' Borealis PP, LG Chemical's SEETEC PP, A.M. 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), etc.

The thermoplastic elastomer composition of the present invention may contain only one type of polyolefin resin (c) such as polypropylene resin, and may contain different types, contents, physical properties, etc. of the monomer units contained. It may contain two or more kinds.

<Crosslinking agent (d)>
The thermoplastic elastomer composition of the present invention preferably contains a cross-linking agent (d) in order to carry out a cross-linking reaction of the above-mentioned component (b) to increase rubber elasticity.

The cross-linking agent (d) is not particularly limited, but the component (b) can be cross-linked without decomposing or cross-linking the component (a) or the grafted product of the component (a) and the component (b). Any cross-linking agent can be used. Specific cross-linking agents (d) include phenolic resins; peroxides; azides; aldehyde-amine reaction products; vinylsilane grafting agents; hydrosilylating agents; urea compounds which may have substituents; substituents. Guanidin which may have a substituent; Xantate which may have a substituent; Dithiocarbamate which may have a substituent; Sulfur compounds such as sulfur, thiazoles, sulfenamides, thiuramidisulfides, etc. An oxime compound such as paraquinonedioxime or dibenzoparaquinonedioxime is used, preferably a phenol-based resin, and more preferably an alkylphenol resin.

The alkylphenol resin of the cross-linking agent (d) is not particularly limited as long as it is a compound having a plurality of alkylphenol structural units. Specific examples of the alkylphenol resin include compounds having a plurality of structural units in which an alkyl group having 1 to 12 carbon atoms is bonded to the ortho-position or para-position of the benzene ring of phenol. More specifically, a compound represented by the following formula (1), which is generally used as a cross-linking agent for rubber, can be mentioned (see US Pat. Nos. 3,287,440 and 3709840).

(In the formula (1), m represents an integer of 0 to 10, X and Y independently represent a hydroxyl group, an alkyl halide or a halogen atom, and R represents a saturated hydrocarbon group having 1 to 15 carbon atoms. In addition, a plurality of Rs may be the same as each other or may be different from each other.)

The compound represented by the above formula (1) can be produced by polycondensing a substituted phenol and an aldehyde with an alkali catalyst, and the shape thereof is usually a solid.

Examples of the alkylphenol resin include alkylphenol formaldehyde and halogenated alkylphenol formaldehyde such as brominated alkylphenol formaldehyde, and more preferably alkyl from the viewpoint of compatibility with ethylene / α-olefin / conjugated diene copolymer. Alkylphenol formaldehyde and / or halogenated alkylphenol formaldehyde having 8 or more carbon atoms in the group.

As these cross-linking agents (d), only one type may be used, or two or more types may be used in combination.

The above-mentioned phenolic resin cross-linking agent is usually used together with a catalyst. Examples of the catalyst that can be used here include catalysts (f) such as stannous chloride, ferric chloride, chlorinated paraffin, chlorinated polyethylene, and chlorosulphonized polyethylene, and iron oxide, titanium oxide, and oxidation. Neutralizers (g) such as magnesium, silicon dioxide, zinc oxide are used. When the phenolic resin is halogenated, the catalyst (f) may not be used.

[Hydrocarbon-based rubber softener (e)]
The thermoplastic elastomer composition of the present invention is carbonized in order to soften the obtained thermoplastic elastomer composition, increase flexibility and elasticity, and improve the processability and fluidity of the obtained thermoplastic elastomer composition. It is preferable to include the softening agent (e) for hydrogen-based rubber.

Examples of the hydrocarbon-based rubber softener (e) include mineral oil-based softeners, synthetic resin-based softeners, and the like, but mineral oil-based softeners are preferable from the viewpoint of compatibility with other components. Mineral oil-based softeners are generally a mixture of aromatic hydrocarbons, naphthenic hydrocarbons and paraffinic hydrocarbons, and paraffinic oils in which 50% or more of all carbon atoms are paraffinic hydrocarbons. Those in which 30 to 45% of all carbon atoms are naphthenic hydrocarbons are called naphthenic oils, and those in which 35% or more of all carbon atoms are aromatic hydrocarbons are called aromatic oils. Among these, the thermoplastic elastomer composition of the present invention preferably contains a paraffinic oil. The hydrocarbon-based rubber softening agent (e) may be used alone or in combination of two or more.

The kinematic viscosity of the hydrocarbon softener (e) at 40 ° C. is preferably 20 centistokes (cSt) or more, more preferably 50 cSt or more, and on the other hand, 800 cSt or less. It is preferably 600 cSt or less. The flash point (COC method) of the hydrocarbon-based rubber softening agent (e) is preferably 200 ° C. or higher, and more preferably 250 ° C. or higher.

When the hydrocarbon softener (e) is used, before the ethylene / α-olefin / non-conjugated diene copolymer (b) of the component (b) is mixed with the components (a) and (c). In addition, a hydrocarbon-based rubber softener (e) and an ethylene / α-olefin / non-conjugated diene copolymer (b) are mixed in advance to obtain an oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber. You may use it.

As a method for producing an oil-extended ethylene / α-olefin / non-conjugated diene copolymer rubber (oil-expanding method), a known method can be used. As an oil spreading method, for example, an ethylene / α-olefin / non-conjugated diene copolymer (b) and a hydrocarbon softener (e) are mechanically kneaded using a mixing roll or a Banbury mixer to obtain oil. A method of spreading, a method of adding a predetermined amount of a softening agent (e) for hydrocarbon-based rubber to an ethylene / α-olefin / non-conjugated diene copolymer (b), and then removing the solvent by a method such as steam stripping. Examples thereof include a method in which a mixture of a crumb-shaped ethylene / α-olefin / non-conjugated diene copolymer (b) and a hydrocarbon-based rubber softening agent (e) is impregnated by stirring with a Henshell mixer or the like.

Oil-developed ethylene / α-olefin / non-conjugated diene copolymer rubbers are available as commercial products. For example, the corresponding product can be selected and used from JSR EPR manufactured by JSR, Mitsui EPT manufactured by Mitsui Chemicals, Esplen (registered trademark) manufactured by Sumitomo Chemical, Keltan (registered trademark) manufactured by LANXESS, and the like.

<Other ingredients>
In addition to the above-mentioned components (a) to (g), the thermoplastic elastomer composition of the present invention may contain any other compounding component according to various purposes as long as the effects of the present invention are not impaired. ..

Optional components include, for example, fillers, antioxidants, heat stabilizers, light stabilizers, UV absorbers, neutralizers, lubricants, fungicides, antiblocking agents, slip agents, dispersants, and colors. Various additives such as agents, flame retardants, antistatic agents, conductivity-imparting agents, metal inactivating agents, molecular weight modifiers, fungicides, fungicides, fluorescent whitening agents, and thermoplastics other than the above components. Examples thereof include resins and elastomers other than the above-mentioned components, and any one of these can be used alone or in combination.

Here, examples of other thermoplastic resins include polyphenylene ether resins, polyamide resins such as nylon 6 and nylon 66, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyoxymethylene homopolymers, and polyoxymethylene. One or more kinds of polyoxymethylene resin such as copolymer and polymethyl methacrylate resin can be mentioned.

When the thermoplastic elastomer composition of the present invention contains another thermoplastic resin or elastomer, the thermoplasticity of the present invention can be effectively obtained by containing the above-mentioned components (a) to (c). The total content of other thermoplastic resins and elastomers in the elastomer composition is preferably 10% by mass or less.

In addition, examples of the filler include one or more of glass fiber, hollow glass ball, carbon fiber, talc, calcium carbonate, mica, potassium titanate fiber, silica, titanium dioxide, carbon black and the like.
When the thermoplastic elastomer composition of the present invention contains these fillers, the content of the filler in the thermoplastic elastomer composition is preferably 20% by mass or less.

<Contents of each component>
The content of the polyolefin (a) having a reactive functional group at least at one end, which is the component (a) in the thermoplastic elastomer composition of the present invention, is the component (b) of ethylene, α-olefin, and non-conjugated diene. The amount is preferably 0.1 to 400 parts by mass with respect to 100 parts by mass of the polymer (b).
When the content of the component (a) is equal to or higher than the above lower limit, the graft is a reaction product of the component (a) and the component (b) due to the introduction of the component (a) into the component (b) as a graft chain. The effect of the product as the above-mentioned compatibilizer can be sufficiently obtained, and it tends to be possible to achieve both rubber elasticity and fluidity at a high level. When the content of the component (a) is not more than the above upper limit, the heat resistance is good, which is preferable.

The thermoplastic elastomer composition of the present invention preferably contains the component (a) in an amount of 1 part by mass or more, particularly 2 parts by mass or more, particularly 300 parts by mass or less, based on 100 parts by mass of the component (b). In particular, it is preferably contained in an amount of 200 parts by mass or less.

The content of the polyolefin resin (c), which is the component (c), in the thermoplastic elastomer composition of the present invention is 100 parts by mass of the ethylene / α-olefin / non-conjugated diene copolymer (b), which is the component (b). On the other hand, it is preferably 0.1 to 400 parts by mass.
The component (c) is a component that contributes to moldability, and when the content of the component (c) is at least the above lower limit, the fluidity and moldability tend to be good, which is preferable. Further, when the content of the component (c) is not more than the above upper limit, the rubber elasticity and flexibility tend to be good, which is preferable.

The thermoplastic elastomer composition of the present invention preferably contains the component (c) in an amount of 1 part by mass or more, particularly 2 parts by mass or more, particularly 300 parts by mass or less, particularly particularly, with respect to 100 parts by mass of the component (b). It is preferably contained in an amount of 200 parts by mass or less.

When the thermoplastic elastomer composition of the present invention contains the cross-linking agent (d) of the component (d), the content of the component (d) is the ethylene / α-olefin / non-conjugated diene copolymer of the component (b). b) With respect to 100 parts by mass, it is preferably 1 part by mass or more, and more preferably 1.5 parts by mass or more in order to sufficiently proceed the crosslinking reaction. On the other hand, from the viewpoint of controlling the cross-linking reaction, it is preferably 10 parts by mass or less, and more preferably 8 parts by mass or less.

As described above, when a phenolic crosslinker such as an alkylphenol resin is used as the crosslinker (d), the phenolic crosslinker such as an alkylphenol resin is preferably used together with the catalyst (f) and the neutralizer (g). In this case, the catalyst (f) is preferably used in an amount of 20 to 100 parts by mass with respect to 100 parts by mass of the phenolic cross-linking agent (d) such as an alkylphenol resin, and the neutralizing agent (g) is used in 100 parts by mass of the catalyst (f). On the other hand, it is preferable to use 30 to 200 parts by mass.

When the thermoplastic elastomer composition of the present invention contains the hydrocarbon-based rubber softening agent (e) of the component (e), the content of the hydrocarbon-based rubber softening agent (e) is the ethylene of the component (b). From the viewpoint of flexibility, the α-olefin / non-conjugated diene copolymer (b) is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and further preferably 20 parts by mass with respect to 100 parts by mass. The above is particularly preferably 30 parts by mass or more. On the other hand, from the viewpoint of production stability, it is preferably 350 parts by mass or less, and more preferably 300 parts by mass or less.

As described above, components other than the above components (a) to (g) are used as long as the effects of the present invention are not impaired.

In order to surely obtain the effect of the present invention by containing the components (a) to (c) as essential components, the thermoplastic elastomer composition of the present invention contains the components (a) and the components in the thermoplastic elastomer composition. The total content of (b) and component (c) is preferably 25% by mass or more, particularly preferably 30% by mass or more.

<Manufacturing method of thermoplastic elastomer composition>
The thermoplastic elastomer composition of the present invention preferably contains a polyolefin (a) having a reactive functional group at least at one end, an ethylene / α-olefin / non-conjugated diene copolymer (b), a polyolefin resin (c), and a necessary material. It is produced by kneading a mixture containing a predetermined amount of other components such as the hydrocarbon softener (e) used according to the above. Preferably, the thermoplastic elastomer composition of the present invention is produced by dynamic heat treatment in the presence of the cross-linking agent (d) during this kneading.

In the present invention, "dynamic heat treatment" means kneading in a molten state or a semi-molten state. This dynamic heat treatment is preferably performed by melt-kneading, and as the mixing and kneading device for that purpose, for example, a non-open type Banbury mixer, a mixing roll, a kneader, a twin-screw extruder and the like are used. Among these, it is preferable to use a twin-screw extruder. A preferred embodiment of the manufacturing method using a twin-screw extruder is a method in which each component is supplied to a raw material supply port (hopper) of a twin-screw extruder having a plurality of raw material supply ports to perform dynamic heat treatment. In kneading, each component may be kneaded at once, or a multi-stage split kneading method may be used in which any component is kneaded and then the other remaining components are added and kneaded.
Further, the components other than the components (a) to (g) may be mixed before the dynamic heat treatment or may be mixed with the thermoplastic elastomer composition after the dynamic heat treatment.

The temperature at which the dynamic heat treatment is performed is usually 180 to 280 ° C, preferably 190 to 250 ° C. The time for performing the dynamic heat treatment is usually 0.1 to 30 minutes.

<Physical characteristics of thermoplastic elastomer composition>
The thermoplastic elastomer composition of the present invention has an excellent melt flow rate (MFR) at a temperature of 230 ° C. and a measurement load of 49 N in accordance with JIS K7210, and thus has excellent moldability. Therefore, 5 to 200 g / 10 minutes, in particular. It is preferably 7 to 150 g / 10 minutes. When the MFR of the thermoplastic elastomer composition is at least the above lower limit value, the fluidity tends to be good, and when it is at least the above upper limit value, burrs and the like during molding can be easily suppressed, which is preferable.

The thermoplastic elastomer composition of the present invention has excellent rubber elasticity in compression set measured under the conditions of a test temperature of 70 ° C., a test time of 22 hours, and 25% compression in accordance with JIS K6262. % Or less, and more preferably 55% or less.

[Molded body / use]
The thermoplastic elastomer composition of the present invention can be made into a molded product by various molding methods usually used for the thermoplastic elastomer composition, for example, injection molding, extrusion molding, hollow molding, compression molding and the like. Among these, injection molding and extrusion molding are preferable. Further, it is also possible to obtain a molded product obtained by performing secondary processing such as laminating molding and thermoforming after performing these moldings.

The thermoplastic elastomer composition of the present invention has excellent rubber elasticity and fluidity, and is used in the fields of automobiles (seals, cushions, boots, etc.), construction fields (gaskets, packings, etc.), and various other miscellaneous goods fields, such as sports equipment (golf clubs, etc.). Tennis racket grips, etc.), industrial parts (hose tubes, gaskets, etc.), home appliances parts (hose, packing, etc.), medical parts (medical containers, gaskets, packing, etc.), food parts (containers, packing, etc.) Etc.), medical equipment parts, electric wires, and other miscellaneous goods can be used in a wide range of fields.

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 ranges are the above-mentioned upper limit or lower limit values and the following. It may be in the range specified by the value of Examples or the combination of the values of Examples.

The raw materials and the evaluation method used in the following examples are as follows.

<Raw materials>
[Polyolefin (a) having a reactive functional group at least at one end]
(A-1): Crystalline polypropylene macromonomer A toluene solution of purified hexane (10000 mL) and modified methylaluminoxane (Toso Finechem Co., Ltd.) was placed in an induction stirring autoclave having a built-in stirring blade and having an internal volume of 24 L, which was replaced with purified nitrogen. 40 mL of "MMAO-3A" 2.1 mmol [Al equivalent atom]) was introduced. The reaction vessel was heated to 70 ° C., propylene was introduced to 0.40 MPa, and rac-dimethylsilylenebis (2- (2- (5-methyl) -frill)) synthesized according to the method described in JP-A-2004-2259. A toluene solution of -4- (4-isopropylphenyl) phenyl-indenyl) zirconium dichloride (20.0 μmol) was press-fitted into the reaction vessel to initiate the polymerization reaction. During the reaction, propylene was added to keep the reactor pressure at 0.40 MPa. After 70 minutes, ethanol was introduced to stop the reaction. The obtained polymer was collected by filtration and dried under reduced pressure until a constant amount was obtained to obtain 2253 g of the polymer. The number average molecular weight ([Mn (GPC)]) of the obtained macromonomer is 27,000, the ^{isotactic pentad fraction (mm mm) measured by 13} C-NMR is 0.978, and the terminal is terminal. The vinyl ratio was 82%. The melting point (Tm) measured by DSC was 154 ° C., and the crystallization temperature (Tc) was 111 ° C.

[Ethylene / α-olefin / non-conjugated diene copolymer (b) and hydrocarbon softener (e)]
(B-1): Ethylene / propylene / 5-ethylidene-2-norbornene copolymer (mass average molecular weight (Mw) in terms of polystyrene = 547,000, content of ethylene units = 67% by mass, 5-ethylidene-2) -Content of norbornene unit = 4.5% by mass) In 100 parts by mass, (e-1): Softener for hydrocarbon rubber (paraffin oil (Diana process oil PW-90, 40 manufactured by Idemitsu Kosan Co., Ltd.) Hydrodynamic viscosity at ° C = 95.54 cSt, flow point = -15 ° C, ignition point = 272 ° C)) 100 parts by mass of oil-extended ethylene / propylene / 5-ethylidene-2-norbornene copolymer

[Polyolefin resin (c)]
(C-1): Propylene homopolymer (number average molecular weight (Mn) = 69,000, melting point = 164 ° C.)
(C-2): Propylene homopolymer (number average molecular weight (Mn) = 20,900, melting point = 163 ° C.)

[Crosslinking agent (d)]
(D-1): Alkylphenol formaldehyde resin having methylol groups at both ends (Tackiroll 201 manufactured by Taoka Chemical Co., Ltd.)

[Catalyst (f)]
(F-1): Stannous chloride (manufactured by Wako Pure Chemical Industries, Ltd.)

[Neutralizer (g)]
(G-1): Zinc oxide (manufactured by Wako Pure Chemical Industries, Ltd.)

<Evaluation method>
Physical properties were measured by the following method.

1. 1. GPC measurement The mass average molecular weight (Mw) of the polyolefin (a), ethylene / α-olefin / non-conjugated diene copolymer (b) and polyolefin resin (c) having a reactive functional group at least at one end is determined by GPC measurement. I asked.
The GPC measurement of the polyolefin (a) and the polyolefin resin (c) having a reactive functional group at least at one end was carried out by using the Alliance GPCV2000 manufactured by Waters Corp. and using a differential refractometer as a detector. As the column, four TSKgel GMH6-HT manufactured by Tosoh Corporation were used. Ortodichlorobenzene was used as the mobile phase solvent, and the solvent was drained at 135 ° C. and 1.0 mL / min. As a standard sample, monodisperse polystyrene manufactured by Polymer Laboratories was used, and a calibration curve regarding the retention time and molecular weight was prepared from the polystyrene standard sample and the viscosity formula of the ethylene-based polymer, and the molecular weight was determined based on the calibration curve. The calculation was performed. As the viscosity formula, [η] = K × M ^α was used, K = 1.38 × 10 ^-4 and α = 0.70 were used for polystyrene, and for ethylene-based polymers. As a result, K = 4.77 × 10 ^-4 and α = 0.70 were used.

Regarding the number average molecular weight ([Mn (GPC)]) of the crystalline polypropylene macromonomer, monodisperse polystyrene manufactured by Polymer Laboratories was also used as a standard sample, and the polystyrene standard sample and the propylene-based polymer were used. A calibration curve regarding the retention time and the molecular weight was prepared from the viscosity formula, and the molecular weight was calculated based on the calibration curve. As the viscosity formula, [η] = K × M ^α is used, K = 1.38 × 10 ^-4 and α = 0.70 are used for polystyrene, and propylene-based polymer is used. , K = 1.03 × 10 ^-4 , α = 0.78 was used.

The measurement conditions of the ethylene / α-olefin / conjugated diene copolymer (b) by 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 (dispersed type, 3.42 μm)
Solvent: o-dichlorobenzene Temperature: 140 ° C
Flow velocity: 1.0 mL / min Injection volume: 200 μL
Concentration: 10 mg / mL
Calibration sample: Polydisperse standard polyethylene Calibration method: Polypropylene conversion using Mark-Houwink equation

2. 2. DSC measurement The melting point (Tm), crystallization temperature (Tc), and glass transition point (Tg) of the polymer were measured by DSC measurement. For DSC measurement, PerkinElmer's "Diamond DSC" is used, and the temperature is 20 ° C for 1 minute isothermal, 10 ° C / min for 20 to 210 ° C, 210 ° C for 5 minutes isothermal, and 10 ° C / min for 210-. The temperature was lowered to 70 ° C., isothermal at −70 ° C. for 5 minutes, and then raised to −70 to 210 ° C. at 10 ° C./min.

3. 3. Measurement of physical properties The thermoplastic elastomer composition is injection-molded with a plunger type injection molding machine (injection molding machine attached to Xplore MC15, a small kneader manufactured by Xplore Instruments) at an injection pressure of 3.5 bar, a cylinder temperature of 210 ° C, and a mold temperature of 40 ° C. The sheet (width 30 mm, length 80 mm, thickness 2 mm) thus obtained was used for the measurement of the following (2), and the sheet cut-out portion was used for the measurement of the following (1).
(1) MFR
Measured in accordance with JIS K7210 (1999) under the conditions of 230 ° C. and a load of 49 N.
(2) Permanent compression strain Measured under the conditions of JIS K6262, test temperature 70 ° C., test time 22 hours, and compression 25%.

[Example 1]
(A-1) 25 parts by mass, 400 parts by mass ((b-1)) of an oil-extended ethylene / propylene / 5-ethylidene-2-norbornene copolymer in which (b-1) and (e-1) are mixed. (E-1) is 200 parts by mass), (c-1) is 75 parts by mass, (d-1) is 4 parts by mass, (f-1) is 4 parts by mass, and (g-1) is 2 parts by mass. Is put into a batch type co-directional twin-screw kneader (Xplore MC15, small kneader manufactured by Xplore Instruments, capacity 15 mL), and then kneaded (dynamic heat treatment) at a set temperature of 210 ° C. and a screw rotation speed of 100 rpm for 5 minutes. A thermoplastic elastomer composition was obtained. The obtained thermoplastic elastomer composition was molded by a plunger type injection molding machine, and the evaluations (1) and (2) above were performed. The evaluation results are shown in Table-1.

[Examples 2 and 3, Comparative Examples 1 and 2]
Each component was blended in the blending amount shown in Table 1 and kneaded in the same manner as in Example 1 to obtain a thermoplastic elastomer composition. Moreover, the evaluations (1) and (2) were carried out in the same manner as in Example 1. The evaluation results are shown in Table-1.

[Evaluation results]
From the comparison between Examples 1 to 3 and Comparative Examples 1 and 2, it was found that the fluidity can be improved while maintaining the rubber elasticity by using the (a-1) crystalline polypropylene macromonomer. In Comparative Example 1, (a-1) crystalline polypropylene macromonomer was not used, but the fluidity was lowered. In Comparative Example 2, the crystalline polypropylene macromonomer of Example 3 (a-1) was replaced with polypropylene having the same molecular weight, but the rubber elasticity was lowered (compressive permanent strain was increased).

In Examples 1 to 3, it is presumed that the following three reactions occurred during kneading.
(Estimated reaction 1) Cross-linking reaction of ethylene / propylene / 5-ethylidene-2-norbornene copolymer (estimated reaction 2) Graft of crystalline polypropylene macromonomer to ethylene / propylene / 5-ethylidene-2-norbornene copolymer Copolymerization reaction (estimated reaction 3) Bonding reaction between ends of crystalline polypropylene macromonomers The reason why the thermoplastic elastomer composition in Examples 1 to 3 was able to maintain fluidity while maintaining rubber elasticity is that of (estimated reaction 2). It is possible that the reaction product functioned as a compatibilizer between the polypropylene phase and the rubber phase.

The thermoplastic elastomer composition of the present invention has excellent rubber elasticity and fluidity, that is, moldability, and is useful in the automobile field such as seals, cushions and boots; the construction field such as gaskets and packings; and the miscellaneous goods field such as grips and casters. Is.

Claims (7)

Polyolefin (a) having a reactive functional group at least at one end,
Ethylene / α-olefin / non-conjugated diene copolymer (b) and
A thermoplastic elastomer composition containing at least a polyolefin resin (c) (however, different from the component (a)).
A thermoplastic elastomer composition in which the polyolefin (a) having a reactive functional group at least one end is a propylene polymer having a vinyl group at one end. With respect to 100 parts by mass of the ethylene / α-olefin / non-conjugated diene copolymer (b), 0.1 to 400 parts by mass of the polyolefin (a) having a reactive functional group at least at one end, and the polyolefin resin (c) The thermoplastic elastomer composition according to claim 1, which contains 0.1 to 400 parts by mass of. The thermoplastic elastomer composition according to claim 1 or 2, further comprising a cross-linking agent (d) and / or a hydrocarbon-based rubber softening agent (e). The thermoplastic elastomer composition according to claim 3, which contains a catalyst (f) together with a cross-linking agent (d). The thermoplastic elastomer composition according to claim 4, which contains a neutralizing agent (g) together with a cross-linking agent (d) and a catalyst (f). The thermoplastic elastomer composition according to any one of claims 1 to 5 , wherein the polyolefin resin (c) is a polypropylene resin having a number average molecular weight of 50,000 or more and 250,000 or less. The melt flow rate (MFR) measured under the conditions of 230 ° C. and a load of 49 N according to JIS K7210 is 5 to 200 g / 10 minutes, and according to JIS K6262, under the conditions of 70 ° C., 22 hours and 25% compression. The thermoplastic elastomer composition according to any one of claims 1 to 6 , wherein the measured compression set is 60% or less.