JP5691719B2 - Resin composition and power cable covering material - Google Patents

Description

  The present invention relates to an amorphous alicyclic structure-containing polymer suitable as a wire coating material, and a resin composition comprising a thermoplastic elastomer which is a copolymer of ethylene and an α-olefin having 6 or more carbon atoms. .

Polymers containing amorphous alicyclic structures such as hydrides of norbornene polymers are used for optical materials and electronic component materials because of their excellent transparency, low birefringence, heat resistance, and low water absorption. It has been.
Patent Document 1 proposes to use a cyclic olefin-based resin as a wire coating material by taking advantage of its dielectric properties and water-resistant tree properties. Here, the melt viscosity characteristics at the time of extrusion molding are improved by using other thermoplastic resins such as polyolefins together, and the mechanical strength, flexibility and flex resistance are improved by using a soft polymer such as polyolefin rubbers together. Is described as improving.

In addition, as an electric wire covering material, it has been studied to laminate polyethylene on a conductor to make an insulating material. Patent Documents 2 and 3 disclose that flexibility and water-resistant trees are improved by using a copolymer of ethylene and octene as polyethylene. These polyethylenes are cross-linked after extrusion coating to form an insulator layer.
In addition, a copolymer of ethylene and octene can be used in combination with other rubber to improve impact resistance and strength characteristics at low temperatures (Patent Document 4). Again, a resin composition containing a rubber component and a copolymer of ethylene and octene is molded by crosslinking.
Patent Document 5 proposes blending a copolymer of ethylene and octene with polyphenylene ether, which is an amorphous resin, as a wire / cable covering material in order to increase tensile elongation at break. However, a coating material using polyphenylene ether does not necessarily have sufficient water vapor barrier properties and flexibility.

Japanese Patent Laid-Open No. 11-189743 JP-A-8-185712 JP 2000-207939 A Japanese Patent Laid-Open No. 11-080427 JP 2004-161929 A

As described above, it has been confirmed that the copolymer of ethylene and octene improves water tree resistance by crosslinking, but when blended with an amorphous resin, it is expected to improve mechanical properties such as flexibility. Met.
However, when a predetermined amount of a copolymer of an α-olefin having 6 or more carbon atoms, such as ethylene and octene, is blended with an amorphous alicyclic structure-containing polymer such as a hydride of norbornene-based polymer, it is not crosslinked. The inventors have found that a resin composition having excellent moldability that can provide a coating material having a water vapor barrier property at a high temperature can be obtained by reducing breakage due to elongation or bending, and the present invention has been completed.

As a result of intensive studies, the present inventors have found that a resin composition comprising an amorphous alicyclic structure-containing polymer and a thermoplastic elastomer that is a copolymer of ethylene and an α-olefin having 6 or more carbon atoms. And the resin composition having a weight ratio of the amorphous alicyclic structure-containing polymer and the thermoplastic elastomer of 60/40 to 90/10 is excellent in moldability and water vapor barrier property at high temperature. It has been found that a material can be provided, and the present invention has been completed.
Moreover, according to this invention, the power transmission cable which has a coating | covering material which consists of the said resin composition is provided.

  Since the resin composition of the present invention is excellent in water vapor barrier properties and flexibility at high temperatures, it can provide a power transmission cable with improved wiring deterioration due to construction and environmental changes.

  The resin composition of the present invention contains an amorphous alicyclic structure-containing polymer and a thermoplastic elastomer that is a copolymer of ethylene and an α-olefin having 6 or more carbon atoms in a predetermined ratio.

-Amorphous alicyclic structure-containing polymer The amorphous alicyclic structure-containing polymer used in the present invention is an amorphous resin (having a melting point) having an alicyclic structure in the main chain and / or side chain. From the viewpoint of mechanical strength, heat resistance, and the like, and those containing an alicyclic structure in the main chain are preferable.

  Examples of the alicyclic structure of the polymer include a saturated cyclic hydrocarbon (cycloalkane) structure and an unsaturated cyclic hydrocarbon (cycloalkene) structure. From the viewpoint of mechanical strength, heat resistance, etc., the cycloalkane structure. And cycloalkene structures are preferred, and those having a cycloalkane structure are most preferred.

  The number of carbon atoms constituting the alicyclic structure is not particularly limited, but is usually 4 to 30, preferably 5 to 20, more preferably 5 to 15 in the mechanical strength, The properties of heat resistance and moldability are highly balanced and suitable.

  The ratio of the repeating unit having an alicyclic structure in the amorphous alicyclic structure-containing polymer used in the present invention may be appropriately selected according to the purpose of use, but is usually 30% by weight or more, preferably It is 50% by weight or more, more preferably 70% by weight. If the proportion of the repeating unit having an alicyclic structure in the amorphous alicyclic structure-containing polymer is too small, the heat resistance is inferior. The remainder other than the repeating unit having an alicyclic structure in the amorphous alicyclic structure-containing polymer is not particularly limited and is appropriately selected depending on the purpose of use.

  Specific examples of the amorphous alicyclic structure-containing polymer include (1) norbornene polymer, (2) monocyclic olefin polymer, (3) cyclic conjugated diene polymer, and (4) vinyl. Examples thereof include alicyclic hydrocarbon polymers and hydrides of (1) to (4). Among these, norbornene-based polymers and hydrides thereof are preferable from the viewpoints of heat resistance, mechanical strength, and the like.

(1) Norbornene-based polymer The norbornene-based polymer is obtained by polymerizing a norbornene-based monomer that is a monomer having a norbornene skeleton, and is obtained by ring-opening polymerization or by addition polymerization. Broadly divided into things.

  As ring-opening polymerization, ring-opening polymers of norbornene monomers, ring-opening polymers of norbornene monomers and other monomers capable of ring-opening copolymerization, and hydrogens thereof. And the like. Examples of the polymers obtained by addition polymerization include addition polymers of norbornene monomers and addition polymers of norbornene monomers and other monomers copolymerizable therewith. Among these, a ring-opening polymer hydride of a norbornene-based monomer is preferable from the viewpoint of heat resistance, mechanical strength, and the like.

Examples of the norbornene-based monomer include bicyclo [2.2.1] hept-2-ene (common name: norbornene) and derivatives thereof (having a substituent in the ring), tricyclo [4.3.0 ^1,6 . 1 ^2,5 ] deca-3,7-diene (common name dicyclopentadiene) and derivatives thereof, 7,8-benzotricyclo [4.3.0.1 ^2,5 ] dec-3-ene (common name) Methanotetrahydrofluorene: 1,4-methano-1,4,4a, 9a-tetrahydrofluorene) and its derivatives, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene (common name: tetracyclododecene) and its derivatives.
Examples of the substituent include an alkyl group, an alkylene group, a vinyl group, an alkoxycarbonyl group, and an alkylidene group, and the norbornene-based monomer may have two or more of these. Specifically, 8-methoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-methyl-8-methoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-ethylidene-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene and the like.
These norbornene monomers are used alone or in combination of two or more.

A ring-opening polymer of a norbornene-based monomer, or a ring-opening polymer of a norbornene-based monomer and another monomer capable of ring-opening copolymerization with a monomer component is a known ring-opening polymerization. It can be obtained by polymerization in the presence of a catalyst. Examples of the ring-opening polymerization catalyst include a catalyst comprising a metal halide such as ruthenium or osmium, a nitrate or an acetylacetone compound, and a reducing agent, or a metal halide or acetylacetone such as titanium, zirconium, tungsten, or molybdenum. A catalyst comprising a compound and an organoaluminum compound can be used.
Examples of the other monomer capable of ring-opening copolymerization with a norbornene monomer include monocyclic olefin monomers such as cyclohexene, cycloheptene, and cyclooctene.
The ring-opening polymer hydride of a norbornene-based monomer is usually obtained by adding a known hydrogenation catalyst containing a transition metal such as nickel or palladium to the polymerization solution of the above-described ring-opening polymer, and then adding a carbon-carbon unsaturated bond. Can be obtained by hydrogenation.

  An addition polymer of a norbornene monomer, or an addition polymer of a norbornene monomer and another monomer copolymerizable therewith, these monomers are added to a known addition polymerization catalyst, for example, It can be obtained by polymerization using a catalyst comprising a titanium, zirconium or vanadium compound and an organoaluminum compound.

Examples of other monomers that can be addition copolymerized with norbornene-based monomers include, for example, α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, and the like. A cycloolefin such as cyclobutene, cyclopentene, cyclohexene, cyclooctene, 3a, 5,6,7a-tetrahydro-4,7-methano-1H-indene, and derivatives thereof; 1,4-hexadiene, 4-methyl -1,4-hexadiene, 5-methyl-1,4-hexadiene, non-conjugated dienes such as 1,7-octadiene; and the like. Among these, α-olefins are preferable and ethylene is particularly preferable.
These other monomers capable of addition copolymerization with norbornene monomers can be used alone or in combination of two or more. In the case of addition copolymerization of a norbornene monomer and another monomer capable of addition copolymerization, other units capable of addition copolymerization with the structural unit derived from the norbornene monomer in the addition polymer. Appropriately, the ratio with the structural unit derived from the monomer is usually in the range of 30:70 to 99: 1, preferably 50:50 to 97: 3, more preferably 70:30 to 95: 5 by weight. Selected.

(2) Monocyclic cyclic olefin polymer As the monocyclic olefin polymer, for example, an addition polymer of a monocyclic olefin monomer such as cyclohexene, cycloheptene, or cyclooctene can be used. it can.
(3) Cyclic conjugated diene polymer As the cyclic conjugated diene polymer, for example, a polymer obtained by subjecting a cyclic conjugated diene monomer such as cyclopentadiene or cyclohexadiene to 1,2- or 1,4-addition polymerization, and The hydride can be used.
(4) Vinyl alicyclic hydrocarbon polymer Examples of the vinyl alicyclic hydrocarbon polymer include polymers of vinyl alicyclic hydrocarbon monomers such as vinyl cyclohexene and vinyl cyclohexane and their hydrides; , Hydrides of aromatic ring moieties of polymers of vinyl aromatic monomers such as α-methylstyrene; and the like, and vinyl alicyclic hydrocarbon polymers and vinyl aromatic monomers, and these Any of random copolymers with other monomers copolymerizable with monomers, copolymers such as block copolymers, and hydrides thereof may be used. Examples of the block copolymer include diblock, triblock, or more multiblock and gradient block copolymers, and are not particularly limited.

  The molecular weight of the amorphous alicyclic structure-containing polymer used in the present invention is appropriately selected according to the purpose of use, but gel permeation of cyclohexane solution (toluene solution when the polymer resin does not dissolve) The polystyrene-reduced weight average molecular weight measured by chromatography is usually 5,000 or more, preferably 5,000 to 500,000, more preferably 8,000 to 200,000, and particularly preferably 10,000 to 100. When it is in the range of 1,000, mechanical strength and moldability are highly balanced, which is preferable.

The glass transition temperature of the amorphous alicyclic structure-containing polymer used in the present invention may be appropriately selected according to the purpose of use, but is usually 50 to 300 ° C, preferably 70 to 250 ° C, particularly preferably. When it is in the range of 90 to 200 ° C., the heat resistance and the moldability are highly balanced and suitable.
The glass transition temperature as used in the field of this invention is measured based on JISK7121.

  Incidentally, these amorphous alicyclic structure-containing polymers can be used alone or in combination of two or more.

A thermoplastic elastomer that is a copolymer of ethylene and an α-olefin having 6 or more carbon atoms. An ethylene-based copolymer that is a copolymer of ethylene and an α-olefin having 6 or more carbon atoms used in the present invention. The polymer (hereinafter sometimes simply referred to as “ethylene-based copolymer”) has a density of usually 0.860 to 0.950 g / cm ³ , preferably 0.862 to 0.920 g / cm ³ . More preferably, it is 0.865 to 0.910 g / cm ³ . When the density is smaller than 0.860 g / cm ³ , the water vapor barrier property of the molded body tends to be inferior, and when the density is larger than 0.950 g / cm ³ , cracking occurs when the molded body is bent. It tends to be easy to do. Here, the density is a value measured based on ASTM D 792.

  The ethylene copolymer has a melt flow rate (hereinafter referred to as MFR) measured at a temperature of 190 ° C. and a load of 2.16 kgf of 0.01 to 30 g / 10 minutes, preferably 0.5 to 5 g / 10. Minutes. If the MFR is too small, the melt fluidity of the resulting resin composition tends to be inferior, and if it is too large, the tensile elongation of the molded product obtained from the resin composition tends to be inferior. Here, MFR is a value measured based on ASTM D 1238.

The content of α-olefin copolymerized with ethylene is not particularly limited as long as the above density and MFR ranges are satisfied, but all the monomer units in the ethylene-based copolymer which is a thermoplastic elastomer are included. When it is 100 mol%, it is usually 2 mol% or more, preferably 40 mol% or less, more preferably 3 to 30 mol%, still more preferably 5 to 25 mol%. Within this range, the tensile elongation is high and the water vapor barrier property is excellent, which is preferable.
Furthermore, as a monomer constituting the ethylene-based copolymer, propylene can be contained as long as it is 10 mol% or less in addition to ethylene and an α-olefin having 6 or more carbon atoms.
In addition, the kind and content of the α-olefin copolymerized with ethylene can be measured by pyrolysis GC-MS.

  Examples of the α-olefin having 6 or more carbon atoms include 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 3-methyl-1-butene, and 4-methyl-1-pentene. Etc. are exemplified. In the present invention, the α-olefin copolymerized with ethylene is preferably an α-olefin having 6 to 10 carbon atoms, more preferably 6 carbon atoms, from the viewpoints of industrial availability, various characteristics, and economical efficiency. Are α-olefins having ˜8, and straight-chain α-olefins (especially 1-octene) having 6 to 8 carbon atoms such as 1-hexene and 1-octene are particularly preferably used. The α-olefin copolymerized with ethylene may be used alone or in combination of two or more.

  As the method for producing the ethylene copolymer, a known polymerization method using a known olefin polymerization catalyst is used. For example, a slurry polymerization method, a solution polymerization method, a bulk polymerization method, a gas phase polymerization method and the like using a complex catalyst such as a Ziegler-Natta catalyst, a metallocene complex, or a nonmetallocene complex can be used. It is also possible to use commercially available products. Specific examples of commercially available products include “Engage (registered trademark)” series, “Affinity (registered trademark)” series, “Infuse (registered trademark)” series manufactured by Dow Chemical Company, and “Tafmer (registered trademark)” manufactured by Mitsui Chemicals, Inc. ) ”Series,“ Kernel (registered trademark) ”series manufactured by Japan Polyethylene Corporation, and the like.

  The resin composition of the present invention contains the above-described ethylene-based copolymer, and the ratio is 60/40 to 90/90 by weight ratio of the amorphous alicyclic structure-containing polymer and the ethylene-based copolymer. 10, preferably 65/35 to 85/15. When the content of the ethylene-based copolymer is small, the tensile elongation and the flexibility tend to be inferior. When the content is large, the molded article obtained using the composition tends to be inferior in the water vapor barrier property.

Other components In the resin composition of the present invention, if necessary, other polymers, various compounding agents usually used in the resin industry, and the like can be used alone or in admixture of two or more.

  Examples of the other polymer include other polymers such as polystyrene, poly (meth) acrylate, polycarbonate, polyester, polyether, polyamide, polyimide, polysulfone, petroleum resin, phenol resin, and the like.

  Various compounding agents commonly used in the resin industry include antioxidants, ultraviolet absorbers, light stabilizers, near infrared absorbers, colorants such as dyes and pigments, plasticizers, antistatic agents, and fluorescent whitening agents. Can be mentioned.

  Examples of the antioxidant include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, etc. Among them, phenolic antioxidants are preferable, and alkyl-substituted phenolic antioxidants are particularly preferable. preferable.

  A conventionally well-known thing can be used as a phenolic antioxidant, for example, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2 , 4-di-t-amyl-6- (1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl) phenyl acrylate and the like, and JP-A Nos. 63-179953 and 1-168643. Acrylate compounds described in Japanese Patent Publication No. 1; octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) ), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5 Di-t-butyl-4-hydroxybenzyl) benzene, tetrakis (methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenylpropionate) methane [ie, pentaerythrmethyl-tetrakis] (3- (3,5-di-t-butyl-4-hydroxyphenylpropionate)], triethylene glycol bis (3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate), etc. Alkyl substituted phenol compounds; 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5-triazine, 4-bisoctylthio-1,3 5-triazine, 2-octylthio-4,6-bis- (3,5-di-t-butyl-4-oxyanilino) -1,3,5-triazine And the like, and the like.

  The phosphorus antioxidant is not particularly limited as long as it is usually used in the general resin industry. For example, triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) Phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10 Monophosphite compounds such as dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl phosphite ), 4,4′isopropylidene-bis (phenyl-di-alkyl phosphite) (carbon of the alkyl moiety) Number 12-15) and the like diphosphite compounds such as. Among these, monophosphite compounds are preferable, and tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and the like are particularly preferable.

  Examples of the sulfur-based antioxidant include dilauryl 3,3-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3,3-thiodipro Pionate, pentaerythritol-tetrakis- (β-lauryl-thio-propionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane, etc. Can be mentioned.

  Examples of the ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) 2H-benzotriazole, 2- (3-tert-butyl-2-hydroxy-5-methylphenyl) -5-chloro-2H- Benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl)- 2H-benzotriazole, 5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) ) -2H-benzotriazole and other benzotriazole ultraviolet absorbers; 4-t-butylphenyl-2-hydroxybenzoate, phenyl-2-hydroxyben 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate, 2- (2H- Benzotriazol-2-yl) -4-methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2- (2-hydroxy-5-t-octylphenyl) -2H-benzotriazole , 2- (2-hydroxy-4-octylphenyl) -2H-benzotriazole and other bezoate ultraviolet absorbers; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone -5-sulfonic acid trihydrate, 2-hydroxy-4-octyloxybenzophenone, 4-dodeca Benzophenone series such as xyl-2-hodoxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone UV absorbers; acrylate UV absorbers such as ethyl-2-cyano-3,3-diphenyl acrylate, 2′-ethylhexyl-2-cyano-3,3-diphenyl acrylate; [2,2′-thiobis (4- t-octylphenolate)]-2-ethylhexylamine nickel and other metal complex ultraviolet absorbers.

  Examples of the light stabilizer include 2,2,6,6-tetramethyl-4-piperidylbenzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, and bis (1,2,2). , 6,6-pentamethyl-4-piperidyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butyl malonate, 4- (3- (3,5-di) -T-butyl-4-hydroxyphenyl) propionyloxy) -1- (2- (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy) ethyl) -2,2,6 Examples thereof include hindered amine light stabilizers such as 6-tetramethylpiperidine.

  When it is necessary to color the molded article of the present invention, any of dyes and pigments can be used within the scope of the present invention and is not limited.

  Various compounding agents usually used in these resin industries can be used within the range not impairing the object of the present invention, and may be used alone or in combination of two or more. It is 0.001-5 weight part normally with respect to 100 weight part of total amounts of an alicyclic structure containing polymer and an ethylene-type copolymer, Preferably it is the range of 0.01-2 weight part.

  Examples of the filler include organic or inorganic fillers, such as silica, diatomaceous earth, alumina, titanium oxide, magnesium oxide, pumice powder, pumice balloon, basic magnesium carbonate, dowamite, calcium oxide, calcium carbonate, Minerals such as calcium sulfate, potassium titanate, barium sulfate, calcium sulfite, talc, clay, mica, asbestos; fibers such as glass fiber, boron fiber, silicon carbide fiber, polyethylene fiber, polypropylene fiber, polyester fiber, polyamide fiber; glass Examples include flakes, glass beads, calcium silicate, montmorillonite, bentonite, graphite, aluminum powder, molybdenum sulfide, and the like.

  These fillers can be added alone or in combination of two or more. The blending ratio of the filler can be appropriately determined according to each function and purpose of use within a range not impairing the object of the present invention.

The mixing method of the resin composition is not particularly limited as long as the compounding agent is sufficiently dispersed in the polymer. For example, a method of kneading a resin in a molten state with a mixer, a single-screw kneader, a twin-screw kneader, a roll, a brabender, an extruder, or the like, a method of dissolving and dispersing in an appropriate solvent, a coagulation method, a casting method, or direct drying There is a method of removing the solvent by a method.
When a biaxial kneader is used, after kneading, it is usually extruded in a rod shape in a molten state, cut into an appropriate length with a strand cutter, and pelletized in many cases.

The resin composition of the present invention is excellent in moldability, and can give a molded article excellent in water vapor barrier and flexibility.
Applications of the resin composition of the present invention include piping, tubes, package films, resin molds and release films for resin molding, wire / cable coating materials, solar cell backsheets, insulating films, capacitor films, etc. In particular, it is suitable for a coating material for electric wires and cables.

The covering material for power transmission cables of the present invention contains the above-described resin composition of the present invention.
When provided in the form of pellets, it can be melted once in a molding machine by an extrusion molding method and then coextruded with the conductor to coat the conductor. Moreover, when the resin composition is dissolved in an organic solvent and provided as a varnish, the conductor can be directly coated and coated.
In any method, the thickness can be appropriately selected depending on the thickness of the covering material and other required characteristics.
When used as a varnish, the solvent used is, for example, an aromatic hydrocarbon such as toluene, xylene or ethylbenzene, an aliphatic hydrocarbon such as n-pentane, hexane or heptane, an alicyclic hydrocarbon such as cyclohexane, chlorobenzene, And halogenated hydrocarbons such as dichlorobenzene and trichlorobenzene. The solvent is used in an amount ratio sufficient to uniformly dissolve or disperse the cyclic polymer and each component to be blended as necessary, and the solid content concentration is usually 1 to 80% by weight, preferably 5 to 60% by weight, More preferably, it is adjusted to 10 to 50% by weight.

  As a method of coating the outer periphery of the conductor with the coating material for a power transmission cable of the present invention supplied in pellets, an extrusion coating method using an extruder similar to a conventionally known wire coating with polyethylene can be applied. Since the resin composition of the invention has a higher glass transition temperature than conventional coating materials such as polyethylene, it is necessary to set the melting temperature during extrusion (cylinder temperature of the extruder) to a higher temperature than before. is there.

  The covering material for power transmission cables of the present invention can crosslink the resin component in the covering material for the purpose of improving heat resistance and mechanical properties. As a crosslinking method, a method of adding an organic peroxide as a crosslinking agent and causing chemical crosslinking by heat treatment, as in the crosslinking method used for a conventionally known crosslinked polyethylene (XLPE) cable (CV cable), electron beam, ultraviolet ray For example, crosslinking with an organic peroxide or electron beam / ultraviolet crosslinking is preferable in consideration of durability and the like. The cross-linking reaction is performed by heat treatment simultaneously with the extrusion molding, but it is preferable to perform heat treatment with nitrogen gas or the like in order to prevent deterioration of the resin or the like. Furthermore, since the cyclic olefin polymer of the present invention has a high glass transition temperature and a high melt extrusion temperature, when crosslinking is performed using an organic peroxide, the decomposition temperature is controlled so that the crosslinking reaction rate can be easily controlled. It is preferable to use an organic peroxide having a high value.

  In the case of using the power transmission cable covering material of the present invention by foaming, as a method thereof, in addition to a foaming method using a conventionally known foaming agent, a gas is directly injected into a molten polymer composition at the time of extrusion. For example, a method of mixing an inert gas in the form of closed cells can be used.

  The cable which coat | covered the conductor using the coating material for power transmission cables of this invention can be used as various power transmission cables. Specific examples include power distribution cables, control / instrumentation cables, electronic equipment cables, plastic cables such as mobile cables; power cables such as insulated cables, high-voltage power cables, plastic power cables; Cables, intra-office cables, broadband cables, high-frequency coaxial cables, high-frequency coaxial (tube) feeders and elliptical waveguides, communication cables such as communication wires and cables, etc. It is particularly effective for high-voltage power cables and high-frequency coaxial cables because of its mechanical properties, bending resistance, flexibility, and the like.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited only to these examples.
In the following examples and comparative examples, “part” or “%” is based on weight unless otherwise specified.

The measuring methods for various physical properties are as follows.
(1) The hydrogenation rate was measured by ¹ H-NMR.
(2) The glass transition temperature is based on JIS K 7121, using a differential scanning calorimeter (product name “DSC6220S11”, manufactured by Nanotechnology), heated to 30 ° C. or higher from the glass transition temperature, and then cooled at a rate of cooling − It measured in the process of cooling to room temperature at 10 degree-C / min, and heating up at a temperature increase rate of 10 degree-C / min after that.
(3) MFR was measured at 190 ° C. and 2.16 kgf using a melt indexer (product name “F-F01”, manufactured by Toyo Seiki Seisakusho Co., Ltd.) based on ASTM D 1238.
(4) The density was measured based on ASTM D 792.
(5) The water vapor transmission rate is a temperature: 70 ° C., humidity: 90% RH based on JIS K 7129 (Method A) using a water vapor transmission tester (product name “L80-5000 type”, manufactured by LYSSY). Measured under conditions.
(6) Tensile elongation was measured based on JIS K 7127 using an autograph (product name “AG-IS 20 kN”, manufactured by Shimadzu Corporation). It pulled until it fractured on the conditions of 10 mm / min of tensile speed, and measured elongation at break as tensile elongation.
(7) In the bending test, a test piece having a thickness of 0.2 mm, a length of 50 mm, and a width of 10 mm was repeatedly bent, and the occurrence of cracks in the test piece was evaluated. A sample which was not broken even after being bent 100 times was designated as “◎”, a sample which was not broken even after being bent 50 times was designated as “◯”, and a sample which was broken within 10 times was designated as “X”.

[Reference Example 1]
Bicyclo [2.2.1] hept-2-ene (hereinafter referred to as “NB”) (120 kg) was added to a reaction vessel charged with 258 liters of cyclohexane at room temperature under a nitrogen stream and stirred for 5 minutes. . Further, triisobutylaluminum was added so that the concentration in the system was 1.0 ml / liter. Subsequently, ethylene was circulated at normal pressure while stirring to create an ethylene atmosphere in the system. The internal temperature of the autoclave was kept at 70 ° C. and pressurized with ethylene so that the internal pressure was 6 kg / cm ^{2 as a} gauge pressure. After stirring for 10 minutes, by adding 0.4 liter of a toluene solution containing isopropylidene (cyclopentadienyl) (indenyl) zirconium dichloride and methylalumoxane prepared in advance, a copolymerization reaction of ethylene and NB Was started. The catalyst concentration at this time is 0.018 mmol / liter for isopropylidene (cyclopentadienyl) (indenyl) zirconium dichloride and 8.0 mmol / liter for methylalumoxane with respect to the entire system.

During the polymerization, ethylene was continuously fed into the system to maintain the temperature at 70 ° C. and the internal pressure at 6 kg / cm ² as a gauge pressure. After 60 minutes, the polymerization reaction was stopped by adding isopropyl alcohol. After depressurization, the polymer solution was taken out, and then contacted with an aqueous solution in which 5 liters of concentrated hydrochloric acid was added to 1 m ^{3 of} water at a ratio of 1: 1 with vigorous stirring to transfer the catalyst residue to the aqueous phase. After leaving this contact liquid mixture, the aqueous phase was separated and removed, and further washed with water twice to purify and separate the polymerization liquid phase.

Next, the purified and separated polymer solution was brought into contact with 3 times the amount of acetone under strong stirring to precipitate a copolymer, and then the solid part (copolymer) was collected by filtration and sufficiently washed with acetone. Further, in order to extract unreacted monomers present in the polymer, this solid part was put into acetone so as to be 40 kg / m ^3, and then an extraction operation was performed at 60 ° C. for 2 hours. After the extraction treatment, the solid part was collected by filtration, and dried under nitrogen flow at 130 ° C. and 350 mmHg for 12 hours to obtain an ethylene / NB copolymer (amorphous alicyclic structure-containing polymer A).

  As described above, the obtained ethylene / NB copolymer (noncrystalline alicyclic structure-containing polymer A) had a Tg of 137 ° C. and an NB unit content of 51 mol%.

[Reference Example 2]
250 parts of cyclohexane is put in a reactor at room temperature and in a nitrogen atmosphere, 0.90 part of 1-hexene, 0.07 part of dibutyl ether and 0.10 part of triisobutylaluminum are mixed, and the mixture is kept at 45 ° C. , 90 parts of tricyclo [4.3.0.1 ^2,5 ] dec-3-ene (hereinafter sometimes abbreviated as “DCP”), 8-ethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] 10 parts of dodec-3-ene (hereinafter sometimes abbreviated as “ETD”) and 17 parts of 0.6% toluene solution of tungsten hexachloride were continuously added over 2 hours for polymerization. . After completion of the polymerization, the polymerization conversion rate of the monomer measured by gas chromatography was 100% at the end of the polymerization.
The obtained polymerization reaction liquid was transferred to a pressure-resistant hydrogenation reactor, and 6 parts of diatomaceous earth-supported nickel catalyst (product name “G-96D”, manufactured by Nissan Gardler, nickel support rate 58%) and 100 parts of cyclohexane were added. In addition, the reaction was carried out at 150 ° C. and a hydrogen pressure of 4.3 MPa for 8 hours. This reaction solution was subjected to pressure filtration (product name “Hunda filter”, manufactured by IHI) at a pressure of 0.25 MPa using Radiolite (registered trademark) # 500 (manufactured by Showa Chemical Industry Co., Ltd.) as a filter bed, and a hydrogenation catalyst. Was removed to obtain a colorless and transparent solution. Subsequently, 0.5 parts of antioxidant per 100 parts of the hydrogenated product: pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals, The product name “Irganox® 1010”) was added to the resulting solution and dissolved. Next, it is sequentially filtered through a Zeta Plus filter 30H (pore size 0.5 to 1 μm, manufactured by Cuno filter), and further filtered through another metal fiber filter (pore size 0.4 μm, manufactured by Nichidai Corp.). Minutes removed.
Next, using a cylindrical concentrator / dryer (manufactured by Hitachi, Ltd.), at a temperature of 270 ° C. and a pressure of 1 kPa or less, cyclohexane and other volatile components as solvents are removed from the solution and directly connected to a concentrator. The molten die was extruded into a strand shape in a molten state, and after cooling, a ring-opened polymer hydrogenated product (amorphous alicyclic structure-containing polymer B) was obtained. Tg was 104 ° C.
In addition, since the polymerization conversion rate at the time of ring-opening polymer synthesis is 100% and the hydrogen conversion rate is as high as 99.9%, a structural unit derived from DCP in the hydrogenated ring-opening polymer ( DCP units) and ETD-derived structural units (ETD units) are estimated to be equal to the amount of monomers used in the production of the ring-opening polymer.

[Reference Example 3]
In a nitrogen atmosphere, 500 parts of cyclohexane, 0.85 part of 1-hexene, 0.20 part of dibutyl ether, and 0.30 part of triisobutylaluminum were mixed in a reactor at room temperature, and then maintained at 45 ° C while maintaining DCP 80 Department, tetracyclo ^{[9.2.1.0 2,10.} 0 ^3,8 ] tetradeca-3,5,7,12-tetraene (hereinafter referred to as “MTF”) 60 parts, and tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] Dodeca-3-ene (hereinafter referred to as “TCD”) 60 parts of norbornene monomer mixture and 40 parts of tungsten hexachloride (0.7% toluene solution) were continuously added over 2 hours. And polymerized. After completion of the polymerization, the polymerization conversion rate of the monomer measured by gas chromatography was 100% at the end of the polymerization.
The obtained polymerization reaction liquid was transferred to a pressure-resistant hydrogenation reactor, 200 parts of cyclohexane was added, 5 parts of nickel-alumina catalyst (manufactured by JGC Chemical Co., Ltd.) was added as a hydrogenation catalyst, and the pressure was increased to 5 MPa with hydrogen. The mixture was heated to 200 ° C. with stirring and reacted for 4 hours to obtain a reaction solution containing a hydrogenated DCP / MTF / TCD ring-opening polymer. The hydrogenation catalyst was removed from the resulting reaction solution by filtration.
Subsequently, 0.5 parts of antioxidant per 100 parts of the hydrogenated product: pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals, The product name “Irganox® 1010”) was added to the resulting solution and dissolved.
Next, using a cylindrical concentrator / dryer (manufactured by Hitachi, Ltd.), at a temperature of 270 ° C. and a pressure of 1 kPa or less, cyclohexane and other volatile components as solvents are removed from the solution and directly connected to a concentrator. The molten die was extruded into a strand in the molten state, and after cooling, a hydrogenated ring-opening polymer (noncrystalline alicyclic structure-containing polymer C) was obtained. Tg was 138 ° C.
In addition, since the polymerization conversion rate at the time of ring-opening polymer synthesis is 100% and the hydrogen conversion rate is as high as 99.9%, a structural unit derived from DCP in the hydrogenated ring-opening polymer ( DCP units), MTF-derived structural units (MTF units), and TCD-derived structural units (TCD units) are estimated to be equal to the amount of monomers used in the production of the ring-opening polymer.

[Example 1]
85 parts of the amorphous alicyclic structure-containing polymer C (Tg = 138 ° C.) obtained in Reference Example 3 and an ethylene-octene copolymer (product name “engage (registered trademark) 8480”; octene content 9.5) Mole%, density = 0.903 g / cm ³ , MFR (190 ° C., 2.16 kgf) = 1 g / 10 min, 15 parts by Dow Chemical Co. were kneaded with a twin-screw kneader and pelletized. A sheet having a thickness of 200 μm was prepared from the pellets using a vacuum press at 240 ° C. and 20 MPa. The produced sheet was subjected to water vapor permeability at 70 ° C., tensile elongation, and bending test. The results are shown in Table 1.

[Example 2]
80 parts of the amorphous alicyclic structure-containing polymer A (Tg = 137 ° C.) obtained in Reference Example 1 and an ethylene-octene copolymer (product name “engage (registered trademark) 8100”; octene content 7.3) 20 parts by mol%, density = 0.870 g / cm ³ , MFR (190 ° C., 2.16 kgf) = 1.1 g / 10 min, manufactured by Dow Chemical Co., Ltd.) are kneaded with a twin-screw kneader and pelletized. did. A sheet having a thickness of 200 μm was prepared from the pellets using a vacuum press at 240 ° C. and 20 MPa. The test was conducted at 70 ° C. water vapor permeability, tensile elongation, and bending test. The results are shown in Table 1.

[Example 3]
70 parts of the amorphous alicyclic structure-containing polymer B (Tg = 104 ° C.) obtained in Reference Example 2 and an ethylene-octene copolymer (product name “engage (registered trademark) 8480”; octene content 9.5) Mole%, density = 0.903 g / cm ³ , MFR (190 ° C., 2.16 kgf) = 1 g / 10 min, manufactured by Dow Chemical Co., Ltd. 30 parts were kneaded with a twin-screw kneader to form pellets. A sheet having a thickness of 200 μm was produced from the pellets using a vacuum press at 220 ° C. and 20 MPa. The test was conducted at 70 ° C. water vapor permeability and tensile elongation, and bending test. The results are shown in Table 1.

[Example 4]
60 parts of the amorphous alicyclic structure-containing polymer B (Tg = 104 ° C.) obtained in Reference Example 2 and an ethylene-octene copolymer (product name “engage (registered trademark) 8200”; octene content 7.3) 40 parts by mol%, density = 0.903 g / cm ³ , MFR (190 ° C., 2.16 kgf) = 5 g / 10 minutes, manufactured by Dow Chemical Co., Ltd. were kneaded with a twin-screw kneader and pelletized. A sheet having a thickness of 200 μm was produced from the pellets using a vacuum press at 220 ° C. and 20 MPa. The test was conducted at 70 ° C. water vapor permeability and tensile elongation, and bending test. The results are shown in Table 1.

[Comparative Example 1]
50 parts of the amorphous alicyclic structure-containing polymer B (Tg = 104 ° C.) obtained in Reference Example 2 and an ethylene-octene copolymer (product name “engage (registered trademark) 8480”; octene content 9.5) Mole%, density = 0.903 g / cm ³ , 50 parts of MFR (190 ° C., 2.16 kgf) = 1 g / 10 minutes, manufactured by Dow Chemical Co., Ltd. were kneaded with a twin-screw kneader and pelletized. A sheet having a thickness of 200 μm was produced from the pellets using a vacuum press at 220 ° C. and 20 MPa. The test was conducted at 70 ° C. water vapor permeability and tensile elongation, and bending test. The results are shown in Table 1.

[Comparative Example 2]
95 parts of the amorphous alicyclic structure-containing polymer B (Tg = 104 ° C.) obtained in Reference Example 2 and an ethylene-octene copolymer (product name “engage (registered trademark) 8480”; octene content 9.5) Mole%, density = 0.903 g / cm ³ , 5 parts of MFR (190 ° C., 2.16 kgf) = 1 g / 10 minutes, manufactured by Dow Chemical Co., Ltd. were kneaded with a twin-screw kneader to be pelletized. A sheet having a thickness of 200 μm was produced from the pellets using a vacuum press at 220 ° C. and 20 MPa. The test was conducted at 70 ° C. water vapor permeability and tensile elongation, and bending test. The results are shown in Table 1.

[Comparative Example 3]
60 parts of the amorphous alicyclic structure-containing polymer B (Tg = 104 ° C.) obtained in Reference Example 2 and an ethylene-butene copolymer (product name “engage (registered trademark) 7380”; density = 0.863 g) / Cm ³ , 40 parts of MFR (190 ° C., 2.16 kgf) = 0.3 g / 10 min, manufactured by Dow Chemical Co., Ltd.) were kneaded with a biaxial kneader to be pelletized. A sheet having a thickness of 200 μm was produced from the pellets using a vacuum press at 220 ° C. and 20 MPa. The test was conducted at 70 ° C. water vapor permeability and tensile elongation, and bending test. The results are shown in Table 1.

[Comparative Example 4]
70 parts of an amorphous alicyclic structure-containing polymer B (Tg = 104 ° C.) obtained from Reference Example 2 and a hydrogenated styrene-based thermoplastic elastomer (SEBS) resin (product name “Tuftec (registered trademark) H1051”, Asahi Kasei) 30 parts) were kneaded with a twin-screw kneader and pelletized. A sheet having a thickness of 200 μm was produced from the pellets using a vacuum press at 220 ° C. and 20 MPa. The test was conducted at 70 ° C. water vapor permeability and tensile elongation, and bending test. The results are shown in Table 1.

From these results, the following can be understood.
When the blending ratio of the thermoplastic elastomer is large, the water vapor permeability at high temperatures is poor (Comparative Example 1), and when it is small, the tensile elongation is low and the flexibility is poor (Comparative Example 2). It was also found that when the thermoplastic elastomer is a copolymer of ethylene and butylene, when the density is low, or when a hydrogenated styrene elastomer is used, the water vapor permeability at high temperatures is poor (comparison). Examples 3, 4). On the other hand, when the weight ratio of the amorphous alicyclic structure-containing polymer to the thermoplastic elastomer is 60/40 to 90/10, the water vapor permeability at high temperature is low, and the tensile elongation and flexibility are excellent. (Examples 1-4).

Claims (2)

A resin composition comprising a non-crystalline alicyclic structure-containing polymer and a thermoplastic elastomer that is a copolymer of ethylene and an α-olefin having 6 or more carbon atoms. A covering material for a power transmission cable comprising a resin composition in which the weight ratio of the coalescence and the thermoplastic elastomer is 60/40 to 90/10. The covering material for power transmission cables according to claim 1, wherein the thermoplastic elastomer is a copolymer of ethylene and 1-octene.