JP6855288B2 - Thermoplastic elastomer compositions, molded articles thereof and methods for producing them - Google Patents

Description

The present invention relates to an olefin-based thermoplastic elastomer composition, more specifically, an olefin-based thermoplastic elastomer composition using a 4-methyl-1-pentene polymer as an olefin-based resin, a molded product thereof, and a method for producing the same. ..

Olefin-based thermoplastic elastomers are lightweight, easy to recycle, and do not generate toxic gas when incinerated. Therefore, from the viewpoint of energy saving, resource saving, and in recent years, vulcanized rubber, in particular, from the viewpoint of protecting the global environment. It is widely used as a product in automobile parts, industrial machine parts, electrical / electronic parts, building materials, etc.

On the other hand, the 4-methyl-1-pentene polymer is used as a material for a mandrel for producing a curved tube hose, for example, but a more flexible material is required. It is known that compounding an ethylene / α-olefin / non-conjugated polyene copolymer such as an ethylene / α-olefin / non-conjugated diene copolymer with a 4-methyl-1-pentene polymer makes it flexible.

Patent Document 1 describes a thermoplastic elastomer composition containing a 4-methyl-1-pentene polymer and a crosslinked rubber such as an ethylene / α-olefin / non-conjugated polyene copolymer as essential components, and a mandrel as its use. Is described.

Patent Document 2 describes a thermoplastic elastomer composition containing a modified 4-methyl-1-pentene polymer and a crosslinked rubber as essential components.

Patent Document 3 describes a thermoplastic elastomer composition containing a 4-methyl-1-pentene polymer, a crosslinked rubber and an unsaturated carboxylic acid as essential components.

Peroxide cross-linking is specifically used as the cross-linking means in Patent Documents 1 to 3.

However, the 4-methyl-1-pentene polymer / peroxide crosslinked rubber-based thermoplastic elastomer composition has a problem that eye tar is generated during extrusion molding.

Further, the thermoplastic elastomer composition needs to be excellent not only in terms of the effect of suppressing eye tar, but also in terms of flexural modulus, heat resistance and mold releasability.

However, the olefin-based thermoplastic elastomer composition using the 4-methyl-1-pentene-based polymer is satisfactory in all aspects of the effect of suppressing eye tar, flexibility (flexural modulus), heat resistance and releasability. There was nothing.

JP-A-11-269330 (Claim 1, paragraph 0003, Examples) JP-A-2002-20562 (Claim 1) JP-A-2006-274119 (Claims 2-4)

An object of the present invention is an olefin-based thermoplastic elastomer composition using a 4-methyl-1-pentene-based polymer, which has an effect of suppressing eye tar, flexibility (flexural modulus), heat resistance, and mold releasability. It is an object of the present invention to provide an olefin-based thermoplastic elastomer composition excellent in terms of points.

The gist of the present invention is as follows.
(1) A structural unit (P) derived from 4-methyl-1-pentene is contained in an amount of 90 mol% or more and 100 mol% or less, and a structural unit derived from an α-olefin other than 4-methyl-1-pentene (hereinafter, "" 30 to 90 parts by mass of the polymer (A) in which the ratio of the structural unit (AQ) to all the structural units is 0 mol% or more and 10 mol% or less.
The structural unit (P) is defined as a structural unit (P) derived from an α-olefin having 2 to 20 carbon atoms other than 4-methyl-1-pentene and 65 mol% or more and less than 90 mol% (hereinafter referred to as “constituent unit (BQ)”). 10 to 70 parts by mass of 4-methyl-1-pentene / α-olefin copolymer (B) containing 10 mol% or more and 35 mol% or less (which may be referred to) (however, (A) and (B) ) Is 100 parts by mass),
Ethylene / α-olefin / non-conjugated polyene copolymer (C) 1-250 parts by mass,
A thermoplastic elastomer composition containing 1 to 20 parts by mass of a phenol resin-based cross-linking agent (D).
(2) 50 to 90 parts by mass of the polymer (A), 10 to 50 parts by mass of the copolymer (B) (however, the total of (A) and (B) is 100 parts by mass), ethylene. The thermoplastic elastomer composition according to (1) above, which comprises 1 to 200 parts by mass of an α-olefin / non-conjugated polyene copolymer (C) and 1 to 20 parts by mass of a phenol resin-based cross-linking agent (D).
(3) 60 to 90 parts by mass of the polymer (A), 10 to 40 parts by mass of the copolymer (B) (however, the total of (A) and (B) is 100 parts by mass), ethylene. The thermoplastic elastomer composition according to (1) above, which comprises 1 to 200 parts by mass of an α-olefin / non-conjugated polyene copolymer (C) and 1 to 20 parts by mass of a phenol resin-based cross-linking agent (D).
(4) The thermoplastic elastomer composition according to any one of (1) to (3) above, which has been dynamically heat-treated.
(5) The polymer (A), the copolymer (B), the ethylene / α-olefin / non-conjugated polyene copolymer (C), and the phenol resin-based cross-linking agent (D) are dynamically mixed. The method for producing a thermoplastic elastomer composition according to any one of (1) to (4) above, which comprises heat-treating.
(6) The thermoplastic elastomer composition according to any one of (1) to (4) above, which is used for extrusion molding.
(7) A molded product obtained by extruding the thermoplastic elastomer composition according to (6) above.
(8) The molded product according to (7) above, which is a mandrel for hose molding.
(9) The method for producing a molded product according to (7) or (8) above, which comprises extruding the thermoplastic elastomer composition according to (6) above.

According to the present invention, the olefin-based thermoplastic elastomer composition using a 4-methyl-1-pentene-based polymer has all of the effect of suppressing eye tar, flexibility (flexural modulus), heat resistance and releasability. An olefin-based thermoplastic elastomer composition excellent in terms of can be provided.

Since the thermoplastic elastomer composition of the present invention contains the phenol resin-based cross-linking agent (D), at least a part thereof is cross-linked, but a dynamically heat-treated one is preferable. The dynamically heat-treated thermoplastic elastomer composition dynamically heats a mixture containing ethylene, α-olefin, and non-conjugated polyene copolymer (C) in the presence of a phenol resin-based cross-linking agent (D). It does not include a blend of the crosslinked product obtained as described above, the polymer (A), and the copolymer (B). The dynamically heat-treated thermoplastic elastomer composition can be distinguished from the blend in terms of oil resistance and rubber elasticity.

Unlike the peroxide-based cross-linking agent, the phenol-resin-based cross-linking agent constitutes a part of the cross-linked product even after the cross-linking reaction, and the unreacted component is not decomposed and remains in the composition. Conceivable.

Therefore, the thermoplastic elastomer composition of the present invention can be obtained by dynamically heat-treating in the presence of a peroxide-based cross-linking agent by oil resistance evaluation, rubber elasticity evaluation and composition analysis. Can be distinguished.

[4-Methyl-1-pentene polymer (A)]
The 4-methyl-1-pentene polymer (A) used in the present invention is a homopolymer of 4-methyl-1-pentene, or 4-methyl-1-pentene and other α-olefins such as ethylene. With α-olefins having 2 to 20 carbon atoms such as propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like. It is a random copolymer. Preferred copolymerization components are α-olefins having 10 to 20 carbon atoms such as 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene or 1-eicosene. The α-olefin copolymerized with 4-methyl-1-pentene may be a mixture of two or more kinds.

When the 4-methyl-1-pentene polymer (A) is a copolymer, the content of 4-methyl-1-pentene is 90 mol% or more and less than 100 mol%, preferably 92 mol% or more and less than 100 mol%. More preferably, a copolymer mainly composed of 4-methyl-1-pentene, which is 94 mol% or more and less than 100 mol%, is preferable. When the content of the copolymerization component is in the range of 10 mol% or less, a composition having more excellent heat resistance can be obtained. As the 4-methyl-1-pentene polymer (A), a random copolymer of 4-methyl-1-pentene and an α-olefin having 10 to 20 carbon atoms is preferable.

The 4-methyl-1-pentene polymer (A) preferably has a melt flow rate (MFR) of 0.1 to 200 g / 10 minutes measured under the conditions of an ASTM D 1238 with a load of 5.0 kg and a temperature of 260 ° C. Is preferably in the range of 1 to 150 g / 10 minutes.

A commercially available product can also be used as the 4-methyl-1-pentene polymer (A). Specific examples thereof include TPX MX001, MX002, MX004, MX021, MX321, RT18 and DX845 (all trademarks) manufactured by Mitsui Chemicals, Inc. Further, even if it is manufactured by another manufacturer, any 4-methyl-1-pentene polymer that satisfies the above requirements can be preferably used. The 4-methyl-1-pentene polymer (A) may be used alone or in combination of two or more.

[4-Methyl-1-pentene / α-olefin copolymer (B)]
The 4-methyl-1-pentene / α-olefin copolymer (B) used in the present invention includes 4-methyl-1-pentene and other α-olefins such as ethylene, propylene, 1-butene, and 1, -A random copolymer with an α-olefin having 2 to 20 carbon atoms such as hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Preferred copolymerization components are α-olefins having 3 to 20 carbon atoms such as propylene, 1-butene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene or 1-eicosene. The α-olefin copolymerized with 4-methyl-1-pentene may be a mixture of two or more kinds.

The content of 4-methyl-1-pentene in the copolymer is 65 mol% or more and less than 90 mol%, preferably 67 mol% or more and 85 mol% or less, more preferably 69 mol% or more and 83 mol% or less, copolymerization. The content of the component is 10 mol% or more and 35 mol% or less, preferably 15 mol% or more and 33 mol% or less, and more preferably 17 mol% or more and 31 mol% or less. When the content of the copolymerization component is in the range of 65 mol% or more and less than 90 mol%, a composition having excellent dispersibility can be obtained.

[Ethylene / α-olefin / non-conjugated polyene copolymer (C)]
The ethylene / α-olefin / non-conjugated polyene copolymer (C) used in the present invention includes ethylene and an α-olefin other than ethylene, preferably an α-olefin having 3 to 20 carbon atoms, and a non-conjugated polyene, preferably. Is a copolymer composed of non-conjugated diene.

The copolymer (C) can be used in "Polymer Manufacturing Process (Industrial Research Council, Inc., Publication p.309-330)" or JP-A-9-71617, JP-A-9-71618 according to the application of the applicant of the present application. No. 9, JP-A-9-208615, JP-A-10-67823, JP-A-10-67824, JP-A-10-110054, WO2009 / 081792 pamphlet, WO2009 / 081794 pamphlet, etc. It can be produced by a conventionally known method as described above.

Examples of the catalyst for olefin polymerization preferably used in the production of the ethylene / α-olefin / non-conjugated polyene copolymer (C) used in the present invention include, for example.
A known Ziegler catalyst composed of a transition metal compound such as vanadium (V), zirconium (Zr), titanium (Ti), and an organoaluminum compound (organoaluminium oxy compound);
A known metallocene catalyst composed of a metallocene compound of a transition metal selected from Group 4 of the periodic table of elements and an organic aluminum oxy compound or an ionized ionic compound, for example, a metallocene catalyst described in JP-A-9-40586. ;
A known metallocene catalyst composed of a specific transition metal compound and a cocatalyst such as a boron compound, for example, the metallocene catalyst described in WO2009 / 072553 pamphlet;
A transition metal compound catalyst comprising a specific transition metal compound and an organometallic compound, an organoaluminum oxy compound, or a compound that reacts with the transition metal compound to form an ion pair, for example, is described in JP-A-2011-52231. Transition metal compound catalyst;
Can be mentioned. In particular, the use of a metallocene catalyst is particularly preferable because the distribution of diene becomes uniform and high cross-linking efficiency can be obtained even if the introduction of diene is small, and the chlorine content derived from the catalyst can be reduced due to the high catalytic activity.

The ethylene / α-olefin / non-conjugated polyene copolymer (C) used in the present invention has a total of 100 mol of a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 to 20 carbon atoms. The content (Ea mol%) of the structural unit derived from ethylene is usually 40 to 90 mol%, preferably 40 to 80 mol%, more preferably 45 to 70 mol%, and further preferably 50 to 50 to%. The content of structural units derived from α-olefins having 60 mol% and 3 to 20 carbon atoms is usually 60 to 10 mol%, preferably 60 to 20 mol%, more preferably 55 to 30 mol%, and further. It is preferably 50-40 mol%.

When the content of the structural unit derived from ethylene and the content of the structural unit derived from the α-olefin having 3 to 20 carbon atoms are within the above ranges, the mechanical properties, rubber elasticity, cold resistance and processability are excellent. It is excellent in that a thermoplastic elastomer composition can be obtained. When the content of the structural unit derived from ethylene is 90 mol% or less and the content of the structural unit derived from the α-olefin having 3 to 20 carbon atoms is 10 mol% or more, the thermoplastic composition becomes flexible and has a low temperature. Excellent rubber elasticity and workability. When the content of the structural unit derived from ethylene is 40 mol% or more and the content of the structural unit derived from the α-olefin having 3 to 20 carbon atoms is 60 mol% or less, the thermoplastic composition has mechanical properties and high temperature. Excellent rubber elasticity. The content of the ethylene structural unit of the ethylene / α-olefin / non-conjugated polyene copolymer (B) and the content of the α-olefin structural unit ^{can be measured by the 13} C-NMR method, for example, the method described later. The peaks can be identified and quantified according to the methods described in the "Polymer Analysis Handbook" (Asakura Shoten, first edition, pp. 184 to 211, published in 2008).

Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 4-methylpentene-1,1-hexene, 1-hexene, 1-octene, 1-nonene. 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicosene, 9-methyldecene-1,11-methyldodecene- Examples thereof include 1,12-ethyltetradecene-1. Of these, propylene, 1-butene, 4-methylpentene-1, 1-hexene and 1-octene are preferable, and propylene is particularly preferable. These α-olefins may be used alone or in combination of two or more.

Specific examples of the non-conjugated polyene include 1,4-hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4,5. Chain non-conjugated diene such as −dimethyl-1,4-hexadiene, 7-methyl-1,6-octadien, 8-methyl-4-ethylidene-1,7-norbornene, 4-ethylidene-1,7-undecadien; Methyltetrahydroinden, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropyriden-2-norbornene, 5-vinylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene , 5-Vinyl-2-norbornene, 5-isopropenyl-2-norbornene, 5-isobutenyl-2-norbornene, cyclopentadiene, norbornene and other cyclic non-conjugated diene; 2,3-diisopropylidene-5-norbornene, 2 Examples thereof include trienes such as −ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornene, and 4-ethylidene-8-methyl-1,7-nonadien. Of these, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, cyclopentadiene, and 4-ethylidene-8-methyl-1,7-nonadien are preferable.

The ethylene / α-olefin / non-conjugated polyene copolymer (C) according to the present invention has an intrinsic viscosity [η] measured in decalin at 135 ° C., which is usually 0.6 to 6.5 dl / g, preferably 0. It is preferably 0.8 to 6.0 dl / g, more preferably 0.9 to 5.5 dl / g. When the ultimate viscosity [η] measured in decalin at 135 ° C. is in this range, it is excellent in that a thermoplastic elastomer having an excellent balance of mechanical properties, rubber elasticity and processability can be obtained.

The iodine value of the ethylene / α-olefin / non-conjugated polyene copolymer (C) according to the present invention is usually 2 to 50 g / 100 g, preferably 5 to 40 g / 100 g, and more preferably 7 to 30 g / 100 g. Is desirable. When the iodine value falls below this range, the cross-linking efficiency in the thermoplastic elastomer decreases, and the rubber elasticity decreases. If the iodine value exceeds this range, the crosslink density becomes too high, the elongation decreases, and the physical characteristic balance may deteriorate.

The ethylene / α-olefin / non-conjugated polyene copolymer (C) according to the present invention has a molecular weight distribution (Mw / Mn) of usually 1.5 to 50, preferably 1.8 to 30 as measured by GPC. It is more preferably 2.0 to 6. When the molecular weight distribution falls below this range, the content of the low molecular weight component decreases, and the processability deteriorates. When the molecular weight distribution exceeds this range, the content of the low molecular weight component increases and the fogging resistance deteriorates.

_{The Mooney viscosity [ML 1 + 4} (100 ° C.)] of the ethylene / α-olefin / non-conjugated polyene copolymer (C) according to the present invention is preferably 15 to 400. When the Mooney viscosity is in this range, the balance between mechanical properties and workability is excellent.

[Phenol resin-based cross-linking agent (D)]
The phenol resin-based cross-linking agent used as a cross-linking agent is also called a phenol-based curative, and refers to a vulcanizing agent containing a phenolic curing resin, preferably a US patent. Examples thereof include a phenolic curative system composed of a phenolic curing resin and a cure activator disclosed in the specification of No. 431216.

Basic components of the systems are substituted phenol in an alkaline medium (e.g., halogen substituted phenol, C ₁ -C ₂ alkyl substituted phenol) or unsubstituted phenol with an aldehyde, or preferably by condensation with formaldehyde, or bifunctional phenol dialcohols (preferably, the para position is C ₅ -C ₁₀ dimethylol phenols substituted with an alkyl group) a phenolic curing resin made by condensation of. Halogenated alkyl-substituted phenolic curable resins produced by halogenation of alkyl-substituted phenolic curable resins are particularly suitable. Phenolic vulcanizers consisting of methylolphenolic curable resins, halogen donors and metal compounds are particularly recommended and are described in detail in US Pat. Nos. 3,287,440 and 3709840. The non-halogenated phenolic curable resin is used together with the halogen donor, preferably with a hydrogen halide scavenger. Generally, a hydrogen halide-based curable resin, preferably a brominated phenol-based curable resin containing 2 to 10% by mass of bromine, does not require a halogen donor, but for example, iron oxide, titanium oxide, or oxidation. Used concurrently with hydrogen halide scavengers such as magnesium, magnesium silicate, silicon dioxide and preferably metal oxides such as zinc oxide. The presence of such a scavenger promotes the cross-linking action of the phenolic curable resin, but in the case of rubber that is not easily vulcanized with the phenolic curable resin, it is desirable to share the halogen donor and zinc oxide. Methods for producing halogenated phenolic curable resins and their use in vulcanizing agents using zinc oxide are described in U.S. Pat. Nos. 2,972,600 and 309,613, the disclosure of which is described in U.S. Pat. No. It shall be incorporated herein by reference with the disclosure of 3287440 and 3709840. Examples of suitable halogen donors are, for example, stannous chloride, ferric chloride, or halogen-donating weights such as chlorinated paraffins, chlorinated polyethylene, chlorosulfonated polyethylene and polychlorobutadiene (neoprene rubber). Coalescence is mentioned. As used herein, the term "activator" means virtually any substance that increases the cross-linking efficiency of phenolic curable resins, and includes metal oxides and halogen donors, which alone. , Or in combination. For more details on phenolic vulcanizing agents, see Vulcanization and Vulcanizing Agents (W. Hoffman, Palmerton Publishing Company). Suitable phenolic curable resins and brominated phenolic curable resins are commercially available, for example from Schenectady Chemicals, Inc. trade names "SP-1045", "CRJ-352", " It can be purchased as "SP-1055" and "SP-1056". Similar operatively equivalent phenolic curable resins can also be obtained from other suppliers.

The phenolic resin-based cross-linking agent is a suitable vulcanizing agent from the viewpoint of preventing fogging because it generates less decomposition products.

The phenolic resin-based crosslinker is used in an amount sufficient to achieve essentially complete vulcanization of the rubber.

[Thermoplastic Elastomer Composition]
In the thermoplastic elastomer composition of the present invention, the blending amount of the 4-methyl-1-pentene polymer (A) is as follows: 4-methyl-1-pentene polymer (A) and 4-methyl-1-pentene. The total amount of the α-olefin copolymer (B) is 30 to 90 parts by mass, preferably 35 to 90 parts by mass, and more preferably 40 to 90 parts by mass with respect to 100 parts by mass. If the amount of the 4-methyl-1-pentene polymer (A) is less than 30 parts by mass, the heat resistance is lowered, while if it exceeds 90 parts by mass, the flexibility is lowered.

The blending amount of the ethylene / α-olefin / non-conjugated polyene copolymer (C) is the 4-methyl-1-pentene polymer (A) and the 4-methyl-1-pentene / α-olefin copolymer (C). B) is 1 to 250 parts by mass, preferably 10 to 230 parts by mass, and more preferably 20 to 210 parts by mass with respect to 100 parts by mass of the total amount. If the blending amount of the ethylene / α-olefin / non-conjugated polyene copolymer (C) is less than 1 part by mass, the flexibility is lowered, while if it exceeds 250 parts by mass, the heat resistance is lowered.

The amount of the phenol resin-based cross-linking agent (D) used is 100% by mass, which is the total amount of the 4-methyl-1-pentene polymer (A) and the 4-methyl-1-pentene / α-olefin copolymer (B). It is 1 to 20 parts by mass, preferably 1 to 15 parts by mass, and more preferably 1 to 12 parts by mass with respect to the parts. If the amount of the phenolic resin-based cross-linking agent (D) used is less than 1 part by mass, oil bleeding occurs, while if it exceeds 20 parts by mass, eye tar is increased.

The thermoplastic elastomer composition of the present invention includes 4-methyl-1-pentene polymer (A), 4-methyl-1-pentene / α-olefin copolymer (B), ethylene / α-olefin / Ingredients other than the non-conjugated polyene copolymer (C) and the phenol resin-based cross-linking agent (D), for example, 4-methyl-1-pentene polymer (A) or 4-methyl-1-pentene / α-olefin Additives such as olefin resins other than the copolymer (B), softeners, heat-resistant stabilizers, antistatic agents, weather-resistant stabilizers, anti-aging agents, fillers, colorants, lubricants, etc. It can be blended within a range that does not impair the object of the invention.

Examples of the olefin-based resin other than the 4-methyl-1-pentene polymer (A) or the 4-methyl-1-pentene / α-olefin copolymer (B) include propylene-based polymers. Homopolypropylene, random copolymers of propylene and α-olefins other than propylene (for example, propylene / ethylene random copolymers, propylene / ethylene / butenerandom copolymers), and α-] of propylene and other than propylene. Examples thereof include one or more propylene-based polymers selected from block copolymers with olefins (for example, propylene / ethylene block copolymers).

The blending amount of the olefin-based resin other than the 4-methyl-1-pentene polymer (A) or the 4-methyl-1-pentene / α-olefin copolymer (B) is 4-methyl-1-pentene. It is usually 20 parts by mass or less, preferably 15 parts by mass or less, based on 100 parts by mass of the total amount of the system polymer (A) and the 4-methyl-1-pentene / α-olefin copolymer (B).

Examples of the softening agent include petroleum-based softeners such as process oil, lubricating oil, paraffin, liquid paraffin, polyethylene wax, polypropylene wax, petroleum asphalt, and vaseline, hydrocarbon-based softeners such as hydrocarbon and colital pitch, and Himashi. Fatroleum-based softeners such as oil, flaxseed oil, rapeseed oil, soybean oil, and coconut oil, waxes such as tall oil, sub (factis), beeswax, carnauba wax, and lanolin, ricinolic acid, palmitic acid, stearic acid, stearic acid Fatty acids and fatty acid salts such as barium acid, calcium stearate, zinc laurate, naphthenic acid, pine oil, rosin or derivatives thereof, terpene resin, petroleum resin, kumaron inden resin, synthetic polymer substances such as tactic polypropylene, dioctyl phthalate. , Dioctyl adipate, ester softeners such as dioctyl sebacate, microcrystallin wax, liquid polybutadiene, modified liquid polybutadiene, liquid polyisoprene, terminal modified polyisoprene, hydrogenated terminal modified polyisoprene, liquid thiocol, hydrocarbon synthetic lubricating oil And so on. Of these, petroleum-based softeners, especially process oils, are preferably used.

4-Methyl-1-pentene polymer (A), 4-methyl-1-pentene / α-olefin polymer (B), ethylene / α-olefin / non-conjugated polyene copolymer (C) and phenol The total amount of the components other than the resin-based cross-linking agent (D) is the total amount of the 4-methyl-1-pentene polymer (A) and the 4-methyl-1-pentene / α-olefin copolymer (B). The amount is usually 20 parts by mass or less, preferably 10 parts by mass or less with respect to 100 parts by mass.

The thermoplastic elastomer composition of the present invention preferably contains a 4-methyl-1-pentene polymer (A), a 4-methyl-1-pentene / α-olefin copolymer (B), and an ethylene / α-. It can be produced by dynamically heat-treating a mixture containing an olefin / non-conjugated polyene copolymer (C) and an additive to be blended if necessary in the presence of a phenol resin-based cross-linking agent (D). it can.

The above-mentioned "dynamic heat treatment" means kneading each component as described above in a molten state.

As the kneading device, conventionally known kneading devices such as an open type mixing roll, a non-open type Banbury mixer, an extruder, a kneader, a continuous mixer and the like are used. Of these, a non-open type kneading device is preferable, and the kneading is preferably performed in an atmosphere of an inert gas such as nitrogen gas or carbon dioxide gas.

The kneading temperature is usually 150 to 280 ° C., preferably 170 to 250 ° C., and the kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes. The shearing force applied is determined as a ^{shear rate in the range of 10 to 50,000 sec -1} , preferably 100 to 20,000 sec ^-1.

The thermoplastic elastomer composition of the present invention is excellent in all of the effect of suppressing eye tar, flexibility (bending elasticity), heat resistance and mold releasability, and is excellent in extrusion moldability. Can be molded using a molding device conventionally used in the above.

The effect of suppressing eye tar of the thermoplastic elastomer composition of the present invention is to suppress the decomposition of 4-methyl-1-pentene polymer by using phenol resin cross-linking instead of peroxide cross-linking to reduce the melt tension. It is presumed that the effect is due to the prevention and the improvement in the dispersibility of the crosslinked rubber (crosslinked ethylene / α-olefin / non-conjugated polyene copolymer) in the composition.

The thermoplastic elastomer composition of the present invention can be used as an elastomer material that requires the above-mentioned properties. For example, it is useful as a material for mandrel used when vulcanizing rubber hoses.

Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.

In the following, each physical property was measured or evaluated by the following method.

[composition]
The content (mol%) of each structural unit in the polymer ^{was measured by the following method (measurement method by 13} C-NMR).

(conditions)
Measuring device: Nuclear magnetic resonance device (ECP500 type, manufactured by JEOL Ltd.)
Observation nucleus: ¹³ C (125 MHz)
Sequence: Single pulse Proton decoupling Pulse width: 4.7 μsec (45 ° pulse)
Repeat time: 5.5 seconds Accumulation number: 10,000 times or more Solvent: o-dichlorobenzene / deuterated benzene (volume ratio: 80/20) Mixed solvent Sample concentration: 55 mg / 0.6 ml
Measurement temperature: 120 ° C
Standard value of chemical shift: 27.50ppm

[Tensile modulus (23 ° C)]
The elastic modulus of the film was measured according to JIS K7127 (1999).

[Ultimate viscosity [η]]
It was measured by the following method using an Ubbelohde viscometer.
After dissolving 20 mg of the polymer in 25 ml of decalin, the specific viscosity ηsp was measured in an oil bath at 135 ° C. using an Ubbelohde viscometer. After adding 5 ml of decalin to this decalin solution and diluting it, the specific viscosity ηsp was measured in the same manner as described above. This dilution operation was repeated twice more, and the value of ηsp / C when the concentration (C) was extrapolated to 0 was determined as the ultimate viscosity [η] (unit: dl / g) (see the formula below).
[Η] = lim (ηsp / C) (C → 0) ・ ・ ・ Equation

[Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn)]
The weight average molecular weight (Mw) of the polymer and the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) are determined by the following gel permeation chromatography (GPC). It is a value calculated by the standard polystyrene conversion method using.

(conditions)
Measuring device: GPC (ALC / GPC 150-C plus type, differential refractometer detector integrated type, manufactured by Waters)
Column: Two GMH6-HT (manufactured by Tosoh Corporation) and two GMH6-HTL (manufactured by Tosoh Corporation) are connected in series. Eluent: o-dichlorobenzene Column temperature: 140 ° C.
Flow rate: 1.0 ml / min

[Melt flow rate (MFR)]
The melt flow rate (MFR) measured at 230 ° C. and a load of 10 kg was determined according to ASTM D1238.

[density]
The density was determined according to JIS K7112 (Density Gradient Tube Method).

[Melting point (Tm)]
It was measured by the following method using a differential scanning calorimetry (DSC) according to JIS K7121.
About 5 mg of the polymer was sealed in a measuring aluminum pan of a differential scanning calorimeter (DSC220C type) manufactured by Seiko Instruments Inc., and heated from room temperature to 200 ° C. at 10 ° C./min. The polymer was held at 200 ° C. for 5 minutes and then cooled to −50 ° C. at 10 ° C./min to completely melt the polymer. After standing at −50 ° C. for 5 minutes, the polymer was heated to 200 ° C. at 10 ° C./min for the second time, and the peak temperature (° C.) at the second heating was defined as the melting point (Tm) of the polymer. When a plurality of peaks were detected, the peak detected on the highest temperature side was adopted.

[Shore A hardness (instantaneous value)]
According to JIS K6253, two press sheets having a thickness of 2 mm were stacked and measured with a Shore A hardness tester.

[Softening temperature]
The softening temperature was determined by the following equipment and measurement conditions.
Equipment: Thermomechanical analyzer TMA Q400 (manufactured by TA Instruments)
Measurement method: Needle insertion method Measurement conditions: 1 mmφ probe used Temperature rise rate: 5 ° C / min

[CS measurement]
The 2 mmt sheets prepared in the examples were laminated and subjected to a compression set test in accordance with JIS K6262. The test conditions were as follows: compression was performed at 70 ° C. for 22 hours with 25% compression using a laminated sheet having a thickness of 12 mm (six sheets of 2 mm thick pieces), and measurement was performed 30 minutes after strain removal (compression).

[Tensile characteristics]
Using a 50t press machine, a sheet sample (2 mm thick) prepared from the thermoplastic elastomer composition (preparation conditions: preheating 230 ° C., 8 minutes, pressurization, 6 minutes) was used as a test sample, and the measurement temperature was 25 ° C. and the tensile speed. A tensile test was carried out under the condition of 500 mm / min, and the tensile breaking strength (TB) and the tensile breaking elongation (EB) were measured.

[Tear test]
The measurement was performed with ISO34-1. The test piece used was an angle type without a notch, and the maximum stress leading to cutting was measured at a tear rate of 500 ± 50 mm / min.

[Volume change rate]
The measurement was performed under the conditions of JIS K6258. The temperature condition was 125 ° C. × 72 h, and the volume change rate before and after oil immersion was measured.

[Weight change rate]
The measurement was performed under the conditions of JIS K6258. As the temperature condition, the weight change rate before and after the oil immersion was measured at 80 ° C. × 24 hours.

[Young's modulus]
Measurements were made based on ISO 527-1. Young's modulus was calculated from the ratio of tensile stress to strain at an elongation of 0.25%.

[Evaluation of releasability]
The releasability of the obtained thermoplastic elastomer from nylon was evaluated using a sample having the following composition.
After superimposing a 2 mm thick sheet of the obtained thermoplastic elastomer and a 100 μm thick film made of UBE nylon (registered trademark) 1030B (manufactured by Ube Industries, Ltd., PA6, M, 27-030), the preheating temperature is 180. A laminated film was prepared by pressing under the conditions of ° C., pressure of 50 kg / cm ² , time of 10 minutes, and cooling of 2 minutes, and the releasability was evaluated.

For comparison, a superposed film of a 2 mm thick sheet made of TPX (registered trademark) MX002 (manufactured by Mitsui Chemicals) and a film made of UBE nylon (registered trademark) 1030B (thickness 100 μm) instead of the thermoplastic elastomer. Was created and used for mold releasability evaluation.

The releasability evaluation was performed by a 180 degree peeling test based on JIS K6854-2. The test conditions are as follows.
-Tension speed 500 mm / min-The test piece was carried out by preparing a 50 mm × 5 mm laminated film.

[Eye evaluation]
The thermoplastic elastomer was extruded under the following conditions using a 50 mm single-screw extruder equipped with a base having a width of 2 mm.
Extrusion time: 10 minutes Barrel rotation speed: 20 rpm
Barrel temperature: C1 / C2 / C3 / C4 / C5 = 160 ° C / 170 ° C / 180 ° C / 190 ° C / 200 ° C

After the extrusion operation was completed, the eye tar around the mouthpiece was collected and quantified (here, the eye tar is a minute mass of the resin composition adhering to the vicinity of the mouthpiece). From the extrusion amount and the amount of eye tar at this time, the amount of eye tar per unit extrusion amount was compared.

<Synthesis example 1>
Polymer A-1 was synthesized by the method described in Comparative Example 9 of WO2006 / 054613. The physical characteristics are shown below.
[composition]
Content of structural unit (P): 96.0 mol%
Type of Monomer Forming Constituent Unit (AQ): 1-Hexadecene / 1-Octadecene Constituent Unit (AQ) Content: 4.0 mol%
[Tension elastic modulus (23 ° C.)] 1200 MPa
[Ultimate viscosity [η]] 2.2 dl / g
[Weight average molecular weight (Mw)] 876000
[Molecular weight distribution (Mw / Mn)] 7.2
[Melt flow rate (MFR)] 21 g / 10 minutes [Density] 833 kg / m ³
[Melting point (Tm)] 224 ° C

<Synthesis Example 2> Synthesis of Polymer B-1 300 ml of n-hexane (dried on activated alumina in a dry nitrogen atmosphere) in an autoclave made of SUS with a stirring blade having a capacity of 1.5 L and sufficiently nitrogen-substituted). After charging 450 ml of 4-methyl-1-pentene at 23 ° C., 0.75 ml of a 1.0 mmol / ml toluene solution of triisobutylaluminum (TIBAL) was charged, and the stirrer was rotated.

Next, the autoclave was heated to an internal temperature of 60 ° C. and pressurized with propylene so that the total pressure (gauge pressure) was 0.40 MPa.

Subsequently, 1 mmol of methylaluminoxane in terms of Al and 0.01 mmol of diphenylmethylene (1-ethyl-3-t-butyl-cyclopentadienyl) (2,7-di-t-) prepared in advance. 0.34 ml of a toluene solution containing butyl-fluorenyl) zirconium dichloride was press-fitted into an autoclave with nitrogen to initiate a polymerization reaction. During the polymerization reaction, the temperature was adjusted so that the internal temperature of the autoclave was 60 ° C.

60 minutes after the start of polymerization, 5 ml of methanol was press-fitted into the autoclave with nitrogen to stop the polymerization reaction, and then the inside of the autoclave was depressurized to atmospheric pressure. After decompression, acetone was added to the reaction solution while stirring the reaction solution to obtain a polymerization reaction product containing a solvent. Next, the obtained polymerization reaction product containing the solvent was dried under reduced pressure at 130 ° C. for 12 hours to obtain 36.9 g of a powdery polymer B-1 as the copolymer (B). The physical characteristics are shown below.

[composition]
Content of structural unit (P): 72.5 mol%
Type of Monomer Forming Constituent Unit (BQ): Propylene Constituent Unit (BQ) Content: 27.5 mol%
[Tensile modulus (23 ° C.)] 500 MPa
[Ultimate viscosity [η]] 1.5 dl / g
[Weight average molecular weight (Mw)] 337,000
[Molecular weight distribution (Mw / Mn)] 2.1
[Melt flow rate (MFR)] 11 g / 10 minutes [Density] 839 kg / m ³
[Melting point (Tm)] Not observed

[Example 1]
Mitsui EPT (trademark) 3072EPM (ethylene / propylene / ENB copolymer manufactured by Mitsui Chemicals, Inc.) as an ethylene / α-olefin / non-conjugated polyene copolymer (catalog value: ethylene content 64% by mass, ENB content 5.4% by mass) , Polymer conversion value (total of ethylene and propylene is 100 mol%): ethylene content 75.8 mol%, propylene content 24.2 mol%, oil spread 40 parts by mass, iodine value 11.5) is 140 mass. Part, 130 parts by mass of polymer A-1, 100 parts by mass of polymer B-1, and brominated alkylphenol / formaldehyde resin (trade name: SP-1055F, manufactured by Extruda) 8.0 as a phenol resin-based cross-linking agent. 0.20 parts by mass of phenolic antioxidant (Irganox 1010, manufactured by BASF Japan Co., Ltd.) and benzotriazole ultraviolet absorber (trade name: Tinuvin 326FL, BASF Japan Co., Ltd.) as antioxidants. 0.20 parts by mass, hindered amine (HALS) -based weather-resistant stabilizer (trade name: Sanol LS-770, manufactured by Sankyo Lifetech Co., Ltd.) 0.10 parts by mass, zinc oxide (2 types of zinc oxide, manufactured by Huxuitech Co., Ltd.) 0 .80 parts by mass, 4.0 parts by mass of carbon black master batch (PE4993, manufactured by Cabot) and 60 parts by mass of softener (Diana process PW-100, paraffin oil), extruder (part number KTX-30, Kobe) Made by Steel Co., Ltd., Cylinder temperature: C1: 50 ° C, C2: 90 ° C, C3: 100 ° C, C4: 120 ° C, C5: 180 ° C, C6: 200 ° C, C7 to C14: 200 ° C, Die temperature: 200 After kneading at ° C., screw rotation speed: 500 rpm, extrusion rate: 40 kg / h), the mixture was dynamically crosslinked to obtain pellets of a thermoplastic elastomer composition.

The obtained thermoplastic elastomer composition was press-molded under the conditions of preheating 230 ° C., 8 minutes, pressurization, and 6 minutes to obtain a test piece in the shape of a 2 mm thick sheet.

The following physical characteristics were evaluated using the obtained 2 mm thick sheet. The results are shown in Table 1.

[Examples 2 to 4]
In Example 1, pellets of the thermoplastic elastomer composition were produced in the same manner as in Example 1 except that the blending ratio of each component was changed as shown in Table 1.
Physical characteristics were evaluated using the obtained pellets. The results are shown in Table 1.

[Comparative Example 1]
In Example 1, 0.2 parts by mass of an organic peroxide (perhexin 25B, manufactured by Nippon Steel & Sumikin Co., Ltd.) and divinylbenzene (DVB810, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) as a cross-linking aid instead of the phenol resin-based cross-linking agent. Pellets of the thermoplastic elastomer composition were produced in the same manner as in Example 1 except that 0.2 parts by mass was added.
Physical characteristics were evaluated using the obtained pellets. The results are shown in Table 1.

From the results of Examples 1 and 2, it can be seen that the thermoplastic elastomer composition of the present invention exhibits excellent heat resistance, mechanical properties, and an effect of suppressing eye stains during extrusion molding.

Claims (3)

Ratio of structural units derived from 4-methyl-1-pentene (P) from 90 mol% to 100 mol% to all structural units derived from α-olefins other than 4-methyl-1-pentene. 30 to 90 parts by mass of the polymer (A) in which is 0 mol% or more and 10 mol% or less.
The structural unit (P) is contained in an amount of 65 mol% or more and less than 90 mol% and 10 mol% or more and 35 mol% or less of a structural unit derived from an α-olefin having 2 or more and 20 or less carbon atoms other than 4-methyl-1-pentene. 10 to 70 parts by mass of the 4-methyl-1-pentene / α-olefin copolymer (B) (however, the total of (A) and (B) is 100 parts by mass).
Ethylene / α-olefin / non-conjugated polyene copolymer (C) 1-250 parts by mass,
A method for producing a thermoplastic elastomer composition containing 1 to 20 parts by mass of a phenol resin-based cross-linking agent (D) , wherein the polymer (A), the copolymer (B), and ethylene / α-olefin are used. A method for producing a thermoplastic elastomer composition, which comprises dynamically heat-treating the non-conjugated polyene copolymer (C) and the phenol resin-based cross-linking agent (D) . The thermoplastic elastomer composition comprises 50 to 90 parts by mass of the polymer (A), 10 to 50 parts by mass of the copolymer (B), and 100 parts by mass of the total of (A) and (B). The production method according to claim 1, further comprising 1 to 200 parts by mass of an ethylene / α-olefin / non-conjugated polyene copolymer (C) and 1 to 20 parts by mass of a phenol resin-based cross-linking agent (D). The thermoplastic elastomer composition comprises 60 to 90 parts by mass of the polymer (A), 10 to 40 parts by mass of the copolymer (B), and 100 parts by mass of the total of (A) and (B). The production method according to claim 1, further comprising 1 to 200 parts by mass of an ethylene / α-olefin / non-conjugated polyene copolymer (C) and 1 to 20 parts by mass of a phenol resin-based cross-linking agent (D).