JPH11189743A - Electric wire coating material of cyclic olefin-based resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a material excellent in balance, having flextural resistance, flexibility and strength characteristics sufficient as an electric wire coating material while keeping excellent dielectric characteristics, water-treeing resis tance and durability which amorphous polyolefin has. SOLUTION: This electric wire coating material contains a cyclic olefin-based polymer containing 20-100 wt.% recurring structural unit derived from a tricylic norbornene-based monomer in total recurring unit of the polymer and having 10,000-100,000 number-average molecular weight (Mn) measured by gel permeation chromatography method and expressed in terms of polyisoprene. An electric wire improved in flexing resistance, flexibility and strength characteristics is produced by covering the outer periphery of a conductor with the electric wire coating material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric wire covering material comprising a cyclic olefin polymer, and more particularly, to an electric wire covering material excellent in bending resistance and flexibility, and a high-pressure electric wire provided with the electric wire covering material around a conductor. It relates to electric wires such as power cables and high-frequency cables.

[0002]

2. Description of the Related Art Conventionally, as insulation materials for power cables, insulation resistance and dielectric strength, water and moisture resistance, chemical resistance,
Crosslinked polyethylene is used from the viewpoint of solvent resistance and the like. However, the insulator made of the cross-linked polyethylene has poor water tree resistance, and when subjected to long-term application of water under water, water tree (mainly cracks originating from impurities in the insulator or defects originating from the crystal structure, (A phenomenon in which a water passage is formed), which results in dielectric breakdown.

[0003] In order to solve the above problem, the outer periphery of the conductor is
Japanese Patent Application Laid-Open No. 5-166418 discloses that a power cable using an amorphous polyolefin as an insulator has a remarkable effect of improving water tree generation degree and AC breakdown voltage. It is also disclosed as a specific example that the use of a norbornene-based ring-opening polymer having a specific structural formula as an insulator has an effect of improving water tree generation degree and AC breakdown voltage. However, the amorphous polyolefin generally has a low elongation of 50% or less,
Since it is inferior in bending resistance and flexibility, even if it is used for a flexible electric wire covering material, cracks and the like are generated, and it is not at a practically usable level, nor norbornene represented by the structural formula described in the publication Amorphous polyolefins having a repeating structural unit obtained by ring-opening polymerization of a monomer with a substituent introduced into the ring are relatively satisfactory among polyolefins, although they are relatively excellent in bending resistance, flexibility and strength properties. It wasn't good.

[0004] From the above, it has been found that a material excellent in balance having sufficient bending resistance, flexibility, and strength characteristics as a wire covering material while maintaining excellent dielectric properties, water tree resistance, and durability has been found. I didn't.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an amorphous polyolefin with sufficient bending resistance, flexibility and strength as a wire covering material while maintaining excellent dielectric properties, water tree resistance and durability. It is to provide a material having an excellent balance.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, a cyclic olefin-based polymer having excellent heat resistance and strength properties has been identified in a total repeating unit of the polymer. A specific molecular weight range containing a certain amount of repeating units of the structure is particularly excellent in elongation, impact strength, etc., so when used as a wire coating material, the flex resistance, flexibility, and strength characteristics are significantly improved. Heading to do
The present invention has been completed.

Thus, according to the present invention, (1) 20 to 100% by weight of a repeating unit derived from a tricyclic norbornene-based monomer is contained in all the repeating units of the polymer, and the polymer is subjected to gel permeation chromatography. The measured number average molecular weight (Mn) was 10,000 in terms of polyisoprene.
An electric wire covering material containing a cyclic olefin-based polymer in an amount of 0 to 100,000 is provided. According to the present invention, there is provided the electric wire covering material according to (1), wherein (2) the cyclic olefin-based polymer is a hydrogenated product of a norbornene-based ring-opening polymer. According to the present invention, (3) Claim 1 is provided on the outer periphery of the conductor.
Alternatively, an electric wire provided with the electric wire covering material according to 2 is provided.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below by dividing them into items.

(Cyclic olefin-based polymer) The cyclic olefin-based polymer used in the present invention is a polymer having 20 to 100% by weight of a repeating unit derived from a tricyclic norbornene-based monomer in all repeating units of the polymer. % And a number average molecular weight of 10,000 to 100,000. The cyclic olefin polymer is a non-crystalline polymer having a hydrocarbon ring structure in the main chain or side chain of the polymer, and specifically, is disclosed in JP-A-63-264646, JP-A-64
No. 1,1705, JP-A-1-168724, ring-opened polymer of a monomer having a norbornene ring and hydrogenated product thereof disclosed in JP-A-1-168725, and JP-A-60-168708. And addition polymers of a monomer having a norbornene ring and α-olefins disclosed in JP-A-6-13657, cyclic olefins and cyclic compounds disclosed in JP-A-7-258362 and the like. Diene addition polymers and hydrogenated products thereof can be mentioned. Among them, the cyclic olefin-based polymer of the present invention is preferably a tricyclic norbornene-based monomer as a raw material monomer. To use.

Among these polymers, more flex resistance,
As those having a remarkable effect of improving the flexibility and mechanical properties, dicyclopentadiene and other monomers having a norbornene ring (norbornene-based monomers) such as tetracyclododecene-based monomers and norbornene-based monomers A ring-opening polymer of
An addition copolymer of dicyclopentadiene, another monomer having a norbornene ring (norbornene-based monomer) and an α-olefin is preferable, and the above-mentioned ring-opening polymer is more preferable.

(Tricyclic norbornene-based monomer repeating structural unit) The tricyclic norbornene-based monomer repeating structural unit forms a double bond in a norbornene ring in a tricyclic norbornene-based monomer. It is a repeating unit formed by ring-opening polymerization or addition polymerization. In the present invention, said 3
It is preferred that the cyclic norbornene-based monomer repeating structural unit is contained in an amount of 20 to 100% by weight, preferably 25 to 100% by weight, more preferably 30 to 100% by weight, based on all the repeating units of the polymer. When the content of the norbornene-based monomer repeating structural unit in the tricyclic form is within the above range, the polymer is highly balanced in terms of flex resistance, flexibility, mechanical properties, workability, and the like, which is preferable.

The tricyclic norbornene monomer used in the present invention refers to an adduct of a substituted or unsubstituted cyclic olefin or cyclic diene with cyclopentadiene.

As a specific example, cyclopentadiene 2
Tricyclo [4.3.1 ^2,5 . 0 ^1,6 ] Deca
3,7-diene (commonly known as dicyclopentadiene), and its partially hydrogenated product (or adduct of cyclopentadiene and cyclopentene), tricyclo [4.3.1 ^2,5 .
0 ^1,6 ] dec-3-ene; tricyclo [4.4.1] which is an adduct of cyclopentadiene and cyclohexadiene
^2,5 . 0 ^1,6 ] undeca-3,7-diene or tricyclo [4.4.1 ^2,5 . [ ^1,6 ] undeca-3,8-diene or a partially hydrogenated product thereof (or an adduct of cyclopentadiene and cyclohexene), ie, tricyclo [4.4.1 ^2,5 . 0 ^1,6 ] undec-3-ene; 5-cyclopentyl-bicyclo [2.2.1] hept-2-ene, which is an adduct of cyclopentadiene with a vinyl compound having an alicyclic group or an aromatic ring group. -Cyclohexyl-bicyclo [2.2.1] hept-2-ene, 5-cyclohexenylbicyclo [2.2.1] hept-2-ene, 5-phenyl-bicyclo [2.2.1] hept-2
Tricyclic norbornenes such as -ene; and the like. Further, substituted products of these norbornenes substituted with polar groups such as halogen, hydroxyl group, ester group, alkoxy group, cyano group, amide group, imide group and silyl group (for example, 5-methoxycarbonylbicyclo [2.2] .1] Hept-2-ene, 5-ethoxycarbonylbicyclo [2.2.1] hept-2-ene, 5-methyl-5-methoxycarbonylbicyclo [2.2.1]
Hept-2-ene, 5-methyl-5-ethoxycarbonylbicyclo [2.2.1] hept-2-ene, bicyclo [2.2.1] hept-5-enyl-2-methylpropionate, bicyclo [2.2.1] Hept-5-enyl-2-methyloctanoate, bicyclo [2.2.1] hept-2-ene-5,6-dicarboxylic anhydride, 5-hydroxymethylbicyclo [2. 2.1] Hept-2-ene, 5,6-di (hydroxymethyl) bicyclo [2.
2.1] Hept-2-ene, 5-hydroxy-i-propylbicyclo [2.2.1] hept-2-ene, 5,6
Norbornene derivatives having a substituent containing an oxygen atom such as -dicarboxybicyclo [2.2.1] hept-2-ene; 5-cyanobicyclo [2.2.1] hept-2-ene
Ene, bicyclo [2.2.1] hept-2-ene-5,
Norbornene derivatives having a substituent containing a nitrogen atom such as 6-dicarboxylic imide).

(Other Norbornene-Based Monomers) In the present invention, other norbornene-based monomers can be used as monomers copolymerizable with the tricyclic norbornene-based monomers.

Other norbornene monomers include:
A bicyclic olefin, norbornene (NB), which is an adduct of ethylene and cyclopentadiene; a tetracyclic olefin, tetracyclododecene (TCD), to which cyclopentadiene is added; and a trimer of cyclopentadiene, which is a pentacyclic diene. Certain pentacyclopentadecadiene, pentacyclopentadecene (also referred to as 2,3-dihydrodicyclopentadiene) which is a pentacyclic olefin in which a part of the unsaturated bond is saturated by hydrogenation, and an aromatic ring in a structural unit. 1,4-methano-1,4,4a, 9a-tetrahydrofluorene (MTF) having the formula: 1,4-methano-1,4,4 obtained by hydrogenating two of the double bonds of the aromatic ring of MTF
a, 4b, 5,8,8a, 9a-octahydro-9H-
Norbornene-based monomers having a cyclohexene ring such as fluorene (MOF); and substituted products thereof. Examples of the substituent include a derivative substituted with a group having no polar group such as an alkyl group, an alkylidene group, or an aromatic group, a hydrogenated derivative, or a derivative obtained by dehydrogenation thereof (for example, 2-norbornene,
-Methyl-2-norbornene, 5,5-dimethyl-2-
Norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-ethylidene-2-norbornene, 5-hexyl-2-norbornene, 5-phenyl-2-norbornene, 5-octyl-2-norbornene, Norbornene derivatives such as 5-octadecyl-2-norbornene and 5-ethylidene-2-norbornene;
1,4: 5,8-dimethano-1,2,3,4,4a,
5,8,8a-2,3-cyclopentadienooctahydronaphthalene, 6-methyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene , 1,4: 5,10: 6,9-trimethano-
1,2,3,4,4a, 5,5a, 6,9,9a, 1
A tetracyclododecene derivative such as 0,10a-dodecahydro-2,3-cyclopentadienoanthracene); a halogen, a hydroxyl group, an ester group, an alkoxy group,
Substitutes (for example, 5-methoxy-carbonyl-2-norbornene, 5-cyano-2-norbornene, 5-methyl-5-methoxycarbonyl) substituted by polar groups such as cyano group, amide group, imide group and silyl group -2-norbornene).

(Other Monomers) In the present invention, in addition to the above-mentioned norbornene-based monomer, if desired, other monomers copolymerizable with the monomer include α-olefins and other cyclic monomers. Monomers such as olefins and cyclic dienes can be copolymerized.

As the α-olefin, in addition to olefins in a narrow sense such as ethylene, propylene, 1-butene and 4-methylpentene-1, olefinic monomers in which a part thereof is substituted with a polar group such as halogen are used. Can be mentioned.

As the cyclic olefin, cyclobutene,
1-methylcyclopentene, 3-methylcyclobutene,
Monocyclic cycloolefins such as 3,4-diisopropenylcyclobutene, cyclopentene, 3-methylcyclopentene, cyclohexene, cyclooctene, 1-methylcyclooctene, 5-methylcyclooctene, cyclooctatetraene, cyclododecene, and the above-mentioned norbornene Among the monomers having a ring, those having one unsaturated bond can be mentioned.

Examples of the cyclic diene include monocyclic dienes such as cyclopentadiene, 1,3-cyclohexadiene, and 1,4-cyclohexadiene, and those having two unsaturated bonds among the above-mentioned monomers having a norbornene ring. Can be mentioned.

Further, in both the ring-opening polymerization and the addition polymerization, various copolymerizable monomers may be copolymerized in the respective catalyst systems to be polymerized. The copolymerizable monomer is
In addition to the above-mentioned monomer having a norbornene ring, α-olefin, cyclic olefin, and cyclic diene, linear or branched dienes such as butadiene and isoprene can be mentioned. The polymerization may be random, block type, or alternating type.
In the case where there is an addition and a 1,4-addition, either may be the main.

When unsaturated bonds remain in the polymer after polymerization,
That is, in the case of a ring-opened polymer of a monomer having a norbornene ring or an addition polymer of a cyclic diene, the weather resistance and thermal stability of the polymer are reduced due to the remaining unsaturated bonds, and this is improved. For the purpose of hydrogenation, 80% or more, preferably 90%, of the unsaturated bonds are added by hydrogenation.
% Or more is preferably used after being saturated. The hydrogenation method and the hydrogenation catalyst can be performed by a known method.

The molecular weight of the polymer is measured by gel permeation chromatography after dissolving it in a good solvent of the polymer such as toluene or tetrahydrofuran and measuring the number average molecular weight (Mn) in terms of polyisoprene. 10,000 to 100,000, more preferably 15,000 to 80,000 and most preferably 20,000.
0 to 50,000. When the molecular weight of the polymer is in the above range, the bending resistance, flexibility, moldability (flow characteristics, viscosity characteristics) and the like of the electric wire coating material are highly balanced, which is preferable.

It is also preferable to remove or reduce the residue of the catalyst and the like from the polymer solution after the polymerization or after the hydrogenation reaction by a known method. The method for recovering the polymer from the polymer solution is not particularly limited, but it is important to remove residual volatile components as much as possible. After performing the washing method described in the catalyst removal method, the solvent is removed by a filtration method, and further heated, or a method of removing by vacuum heating, or directly heating the resin solution from which metal contaminants have been removed by a precipitation aggregation method, Alternatively, there is a method of removing the solvent by heating under vacuum.

The heat resistance of the cyclic olefin resin is described, for example, by the glass transition temperature. The glass transition temperature is determined by the type of the monomer, the ratio of the monomer when copolymerized, the molecular weight,
Although it depends on the hydrogenation rate and the like, when used as an electric wire coating material, it is 60 to 220 ° C., preferably 70 to 200 ° C.
C, more preferably 80 to 190C.

Further, when used as an electric wire coating material, it is preferable that the cyclic olefin resin contains few foreign substances. As a method for suppressing foreign matter, for example, after the polymerization reaction or the hydrogenation reaction, the polymer solution can be filtered with a filter having a pore size of 0.2 μm or less to precisely remove metal residues and foreign matter.

The cyclic olefin polymer used in the present invention may contain a crosslinking agent, a foaming agent, a flame retardant, and other polymers for use as a wire covering material.

(Crosslinking Agent) The crosslinking agent used in the present invention is not particularly limited, but (1) an organic peroxide, (2)
A cross-linking agent that exhibits an effect by heat, (3) a crosslinking agent that exhibits an effect by light, and the like are used. (1) Organic peroxide Examples of the organic peroxide include ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane , 2, 2
Peroxy ketals such as -bis (t-butylperoxy) butane; t-butyl hydroperoxide,
Hydroperoxides such as 2,5-dimethylhexane-2,5-dihydroperoxide; dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, α Dialkyl peroxides such as, α'-bis (t-butylperoxy-m-isopropyl) benzene; octanoyl peroxide;
Diacyl peroxides such as isobutyryl peroxide; peroxy esters such as peroxydicarbonate. Among these, from the viewpoint of the moldability and the performance of the resin after crosslinking, a crosslinking agent having a high decomposition temperature and excellent heat resistance is preferable, and hydroperoxides, dialkyl peroxides, and peroxyketals are preferable, and dicumyl par Oxide, 1,1-bis (t-
Butylperoxy) 3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5-dimethylhexane-
2,5-dihydroperoxide and the like are particularly preferred.

(2) Crosslinking agent that exerts its effect by heat
The crosslinking agent is not particularly limited as long as the crosslinking agent can be used.
, Triamine or higher aliphatic polyamines, fats
Cyclic polyamine, aromatic polyamine bis azide, acid anhydride
Substances, dicarboxylic acids, polyhydric phenols, polyamides, etc.
No. As a specific example, for example, hexamethyl
Rangeamine, triethylenetetramine, diethyleneto
Aliphatic amines such as lamine, tetraethylenepentamine, etc.
Liamine; diaminocyclohexane, 3 (4), 8
(9) -Bis (aminomethyl) tricyclo [5.2.
1.0^{2, 6}Decane; 1,3- (diaminomethyl) cyclo
Rohexane, mensendiamine, isophoronediamine N
-Aminoethylpiperazine, bis (4-amino-3-meth
Tylcyclohexyl) methane, bis (4-aminocyclo)
Alicyclic polyamines such as hexyl) methane; 4,4'-
Diaminodiphenyl ether, 4,4'-diaminodiph
Phenylmethane, α, α'-bis (4-aminophenyl)
-1,3-diisopropylbenzene, α, α'-bis
(4-aminophenyl) -1,4-diisopropylben
Zen, 4,4'-diaminodiphenylsulfone, meta
Aromatic polyamines such as phenylenediamine; 4,4-
Bisazidobenzal (4-methyl) cyclohexanone,
4,4'-diazidochalcone, 2,6-bis (4'-a
Zidobenzal) cyclohexanone, 2,6-bis (4 '
-Azidobenzal) -4-methyl-cyclohexanone,
4,4'-diazidodiphenyl sulfone, 4,4'-di
Azidodiphenylmethane, 2,2'-diazidostilbe
Bisazides such as phthalic anhydride, pyromellitic anhydride
Acid, benzophenonetetracarboxylic anhydride, Nagic
Acid anhydride, 1,2-cyclohexanedicarboxylic acid, anhydride
Maleic acid-modified polypropylene, maleic anhydride-modified ring
Anhydrides such as linear olefin resin; fumaric acid, phthalic acid
Acid, maleic acid, trimellitic acid, hymic acid, etc.
Carboxylic acids; phenol novolak resin, cresol
Polyphenols such as novolak resin; tricyclodeca
Diol, diphenylsilane diol, ethylene glycol
Coal and its derivatives, diethylene glycol and its
Derivatives, triethylene glycol and its derivatives
Polyhydric alcohols: nylon-6, nylon-66, na
Iron-610, nylon-11, nylon-612,
Nylon-12, Nylon-46, methoxymethylated
Lamide, polyhexamethylenediamine terephthalamide
Polyamides such as polyhexamethylene isophthalamide
And the like. These may be of one kind or two or more kinds.
It may be used as a mixture. Among these, cured products
Heat resistance, mechanical strength, adhesion to metal, dielectric properties (low dielectric constant)
Due to its excellent electrical conductivity and low dielectric loss tangent)
Polyamines, acid anhydrides, polyhydric phenols, polyhydric alcohols
Preferred are alcohols, among which 4,4-diaminodiffee
Nylmethane (aromatic polyamines), maleic anhydride
Cyclic olefin resin (acid anhydride), polyhydric phenols
Etc. are particularly preferred. Also, if necessary, a curing accelerator
Can increase the efficiency of the crosslinking reaction.
You. Although the amount of the crosslinking agent is not particularly limited,
The bridge reaction is carried out efficiently and the obtained cured product
From the viewpoints of improving the performance and economical efficiency, the polymer 1
0.1 to 30 parts by weight, preferably 1 to 100 parts by weight
Used in the range of ２０20 parts by weight. Less amount of crosslinker
When cross-linked, cross-linking hardly occurs, and sufficient heat resistance and solvent resistance are obtained.
And too much water absorption of the crosslinked resin
It is not preferable because properties such as properties and dielectric properties are deteriorated.
Therefore, when the compounding amount is in the above range, these characteristics are high.
It is suitable to be balanced each time.

Examples of the curing accelerator include amines such as pyridine, benzyldimethylamine, triethanolamine, triethylamine, and imidazole. The curing speed is adjusted and the efficiency of the crosslinking reaction is further improved. It is added for the purpose. The amount of the curing accelerator is
Although not particularly limited, it is used in an amount of 0.1 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the above-described polymer. , Dielectric properties, water absorption, etc. are well balanced. In particular, imidazoles are preferable because of their excellent dielectric properties.

(3) Crosslinking agent that exerts an effect by light The crosslinking agent that exerts an effect by light is irradiation of actinic rays such as ultraviolet rays such as g-rays, h-rays and i-rays, far ultraviolet rays, x-rays and electron rays. Is not particularly limited as long as it is a photoreactive substance that reacts with the polymer to generate a cross-linking compound, and examples thereof include an aromatic bisazide compound, a photoamine generator, and a photoacid generator.

Specific examples of the aromatic bis azide compound include 4,4′-diazidochalcone and 2,6-bis (4 ′
-Azidobenzal) cyclohexanone, 2,6-bis (4'-azidobenzal) 4-methylcyclohexanone, 4,4'-diazidodiphenylsulfone, 4,
Representative examples include 4'-diazidobenzophenone, 4,4'-diazidodiphenyl, 2,7-diazidofluorene, 4,4'-diazidophenylmethane, and the like. These can be used alone or in combination of two or more.

Specific examples of the photoamine generator include o-nitrobenzyloxycarbonyl carbamate of aromatic amine or aliphatic amine, 2,6-dinitrobenzyloxycarbonyl carbamate and α, α-dimethyl-
3,5-dimethoxybenzyloxycarbonyl carbamate and the like, and specifically, aniline, cyclohexylamine, piperidine, hexamethylenediamine, triethylenetetraamine, 1,3- (diaminomethyl)
O-Nitrobenzyloxycarbonyl carbamates such as cyclohexane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, and phenylenediamine. These can be used alone or in combination of two or more.

The photoacid generator is a substance that generates a Bronsted acid or a Lewis acid upon irradiation with actinic rays, such as an onium salt, a halogenated organic compound,
Examples include quinonediazide compounds, α, α-bis (sulfonyl) diazomethane compounds, α-carbonyl-α-sulfonyl-diazomethane compounds, sulfone compounds, organic acid ester compounds, organic acid amide compounds, and organic acid imide compounds. These compounds which can be cleaved by irradiation with actinic rays to generate an acid may be used alone or in combination of two or more.

The amount of the photoreactive compound to be added is not particularly limited, but it is preferred that the reaction with the polymer be carried out efficiently, that the physical properties of the obtained cross-linked resin be not impaired, and that economic efficiency be met. 0.1 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the polymer. If the added amount of the photoreactive substance is too small, crosslinking is unlikely to occur, and sufficient heat resistance and solvent resistance cannot be obtained.If the added amount is too large, properties such as water absorption and dielectric properties of the crosslinked resin deteriorate. Therefore, it is not preferable. Therefore, when the amount is within the above range, these characteristics are highly balanced and suitable.

(Foaming agent) Foaming agents are especially used for communication cables,
It can be added when used for electric wires that require low dielectric constant and low dielectric loss tangent, such as coaxial cables for computers and high-frequency cables. Conventionally, synthetic rubber, vinyl chloride resin, polyethylene, polypropylene, ABS
Compounded in resin, etc., decompose by heating the composition, generating carbon dioxide gas, nitrogen gas, ammonia, etc.,
There is no particular limitation as long as it can form a cellular structure in the polymer, but those conventionally used for foamed polyethylene are preferred. Specific examples include inorganic foaming agents such as sodium bicarbonate, ammonium bicarbonate, and ammonium carbonate; N, N'-dinitrosopentamethylene.
Nitroso compounds such as tetramine, N, N'-dimethyl-N, N'-dinitroso terephthalamide; azo compounds such as azodicarbonamide, azobis / isobutyronitrile, barium / azodicarboxylate; benzene / sulfonyl / hydrazide , P, p'-oxybis (benzenesulfonyl hydrazide), benzene-
Sulfonyl hydrazides such as a mixture of 1,3-disulfonyl hydrazide and paraffin chloride, toluene sulfonyl hydrazide and derivatives thereof; and other blowing agents such as p-toluene sulfonyl semicarbazide, trihydrazino triazine, and zinc-amine complex compounds. And the like. In particular, when using dinitroso-pentamethylene-tetramine (DPT) or the like, a foaming aid can be added for the purpose of promoting the decomposition and lowering the decomposition temperature, and organic acids such as salicylic acid, urea, and the like. Is used.

(Flame retardant) Although the flame retardant is not an essential component,
In particular, in the case of a wire such as a high-voltage power cable through which a large amount of current flows, it is preferable to add it. The flame retardant is not particularly limited, but is preferably one that does not decompose, modify, or deteriorate with a curing agent, and a halogen-based flame retardant is usually used.
As the halogen-based flame retardant, various chlorine-based and bromine-based flame retardants can be used, but the flame retardant effect, heat resistance at the time of molding, dispersibility in the resin, influence on the physical properties of the resin, etc. are considered. From
Hexabromobenzene, pentabromoethylbenzene,
Hexabromobiphenyl, decabromodiphenyl, hexabromodiphenyloxide, octabromodiphenyloxide, decabromodiphenyloxide, pentabromocyclohexane, tetrabromobisphenol A, and derivatives thereof [for example, tetrabromobisphenol A-bis (hydroxyethyl ether); Tetrabromobisphenol A-bis (2,3-dibromopropyl ether), tetrabromobisphenol A-bis (bromoethyl ether), tetrabromobisphenol A-bis (allyl ether), etc.], tetrabromobisphenol S, and derivatives thereof [ For example, tetrabromobisphenol S-bis (hydroxyethyl ether), tetrabromobisphenol S-bis (2,3-
Dibromopropyl ether), etc.], tetrabromophthalic anhydride, and derivatives thereof [eg, tetrabromophthalimide, ethylenebistetrabromophthalimide, etc.],
Ethylenebis (5,6-dibromonorbornene-2,3
-Dicarboximide), tris- (2,3-dibromopropyl-1) -isocyanurate, an adduct of the Diels-Alder reaction of hexachlorocyclopentadiene,
Tribromophenyl glycidyl ether, tribromophenyl acrylate, ethylene bistribromophenyl ether, ethylene bispentabromophenyl ether, tetradecabromodiphenoxybenzene, brominated polystyrene, brominated polyphenylene oxide, brominated epoxy resin, brominated polycarbonate, poly Pentabromobenzyl acrylate, octabromonaphthalene,
It is preferable to use hexabromocyclododecane, bis (tribromophenyl) fumaramide, N-methylhexabromodiphenylamine and the like. The amount of flame retardant added
Usually 3 to 150 parts by weight, based on 100 parts by weight of the polymer,
Preferably from 10 to 140 parts by weight, particularly preferably from 15 to 140 parts by weight.
120 parts by weight. As a flame retardant aid to more effectively exhibit the flame retardant effect of the flame retardant, for example, antimony trioxide, antimony pentoxide, sodium antimonate,
An antimony-based flame retardant such as antimony trichloride can be used. These flame retardant aids are used in a proportion of usually 1 to 30 parts by weight, preferably 2 to 20 parts by weight, based on 100 parts by weight of the flame retardant.

(Other Polymers) For the purpose of improving mechanical properties and moldability, other polymers such as thermoplastic resins and soft polymers may be blended with the cyclic olefin polymer of the present invention. it can.

As other thermoplastic resins, for example,
Polyolefins such as low density polyethylene, high density polyethylene, linear low density polyethylene, ultra low density polyethylene, polypropylene, polybutene, polypentene;
Polyesters such as polyethylene terephthalate and polybutylene terephthalate; nylon-6, nylon-6
And polyamides such as 6; ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, polystyrene, polyphenylene sulfide, polyphenylene ether, polyamide, polyester, polycarbonate and the like. These other thermoplastic resins can be used alone or in combination of two or more, and the blending amount is appropriately selected within a range not to impair the object of the present invention. In particular, when the amorphous cyclic olefin polymer of the present invention and a crystalline resin such as polyethylene are blended, the melt viscosity characteristics at the time of extrusion molding are highly balanced, which is preferable.

The soft polymer is not particularly limited as long as at least one Tg is 40 ° C. or less. Specifically, styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, styrene-butadiene random Random or block copolymers of aromatic vinyl monomers and conjugated diene-based monomers such as copolymers and hydrogenated products thereof; polyisoprene rubber;
Polyolefin rubber such as ethylene-propylene copolymer, ethylene / α-olefin copolymer, propylene / α-olefin copolymer, ethylene-propylene-diene copolymer, α-olefin-diene copolymer, diene copolymer Diene-based copolymers such as copolymers, isobutylene-isoprene copolymers, isobutylene-diene copolymers; copolymers of norbornene-based monomers and ethylene or α-olefins; norbornene-based monomers and ethylene α-olefins And a norbornene-based rubbery polymer such as a ring-opening polymer of a norbornene-based monomer. These other soft polymers, each alone,
Alternatively, two or more kinds can be used in combination, and the compounding amount is appropriately selected within a range that does not impair the object of the present invention. In particular, when a soft polymer is blended, the mechanical strength, elongation (flexibility) and bending resistance of the coating material are further improved, which is preferable.

(Other Compounding Agents) In addition to the cyclic olefin resin used in the present invention, various other compounding agents commonly used in the resin industry can be used.

Examples of the stabilizer include phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Of these, phenol-based antioxidants are preferred, and alkyl-substituted phenol-based antioxidants are preferred. Agents are particularly preferred. Furthermore, in order to prevent volatilization during molding,
It is desirable that the vapor pressure at 10 ° C. be 10 ⁻⁶ Pa or less.
These stabilizers are used alone or in combination of two or more. The amount of the stabilizer is appropriately selected according to the purpose of use.
It is usually in the range of 0.001 to 10 parts by weight with respect to 00 parts by weight.

A lubricant is used as needed for the purpose of improving moldability and the like. As a lubricant,
Partial ester of polyhydric alcohol, full ester of polyhydric alcohol (95% of alcoholic hydroxyl group of polyhydric alcohol)
% Of which are esterified), higher saturated alcohols, partial ethers of polyhydric alcohols and the like. Among them, full esters of polyhydric alcohols, especially full esters of polyhydric alcohols and OH group-containing higher saturated fatty acids, are mentioned. Esters are preferred, or higher saturated alcohols are particularly preferred. Furthermore, in order to prevent volatilization at the time of molding, it is desirable that the vapor pressure at 20 ° C. be 10 ⁻⁶ Pa or less. The blending amount of the lubricant is appropriately selected according to the purpose of use, but is usually 10 parts by weight or less, preferably 5 parts by weight or less, more preferably 3 parts by weight or less based on 100 parts by weight of the cyclic olefin polymer. Range. However, if the lubricant is used in a large amount, the lubricant oozes out of the surface of the molded body, for example, adheres to the surface of the molded body in the form of oil droplets, or adheres to the surface of the mold and may lower the transferability. It is preferable that the amount used is about 1 part by weight or less.

Other compounding agents include, for example, dyes,
Examples include antistatic agents, ultraviolet absorbers, light stabilizers, waxes, and the like. These other compounding agents can be used alone or in combination of two or more.

(Blend) Further, the electric wire coating material of the present invention is blended with a commonly used insulating coating material (polyethylene, polypropylene, a crosslinked product thereof and the like) at an arbitrary blending ratio to provide durability and heat resistance. Properties, workability, etc. can be improved. In particular, the flow characteristics of crystalline polymers such as polyethylene and polypropylene can be improved to prevent eccentricity of the conductor.

(Electric wire coating material) These compounds can be mixed by isolating the cyclic olefin resin and then melt-mixing with a kneader such as a single-screw extruder, a twin-screw extruder, a roll, or a Banbury mixer. Although it is good, it is preferable to add and mix with the cyclic olefin resin solution before filtration. Further, the compounding agents may be added after dissolving each using an appropriate solvent, or may be added by heating the solution as necessary. The cyclic olefin resin solution may be heated similarly. The cyclic olefin resin is often used after being processed into a size of rice grain called a pellet so as to be easily handled at the time of molding. As described above, an additive necessary for the cyclic olefin-based polymer is added to obtain a wire covering material composed of the cyclic olefin resin composition.

The wire covering material comprising the cyclic olefin-based resin composition obtained as described above is provided in the form of pellets as described above. Can be coated together with the conductor by co-extrusion, but what is provided as a varnish dissolved in an organic solvent can be directly coated on the conductor. These methods can be appropriately selected depending on the thickness of the coating material and other required characteristics. When used as a varnish, the solvent used, for example, toluene, xylene, aromatic hydrocarbons such as ethylbenzene, n-pentane, hexane, aliphatic hydrocarbons such as heptane, alicyclic hydrocarbons such as cyclohexane, chlorobenzene, Examples thereof include 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, if necessary, each component to be blended, and usually has a solid content of 1 to 80% by weight, preferably 5 to 60% by weight, More preferably, it is adjusted to be 10 to 50% by weight.

The coating material has a melt viscosity of 100 to 2 from the viewpoints of handling and process advantages.
It is preferably 50 poise or less, more preferably 20 poise or less in the range of 00 ° C.

(Extrusion Molding Method) As a method for coating the outer periphery of the conductor with the electric wire coating material of the present invention supplied in pellets, an extrusion coating method using an extruder similar to a conventionally known electric wire coating with polyethylene is applied. However, since the cyclic olefin-based polymer composition of the present invention has a higher glass transition temperature than conventional coating materials such as polyethylene, the melting temperature during extrusion (cylinder temperature of an extruder) is as follows: It is necessary to set the temperature higher than before.

(Crosslinking) The electric wire coating material in the present invention is:
The cyclic olefin polymer in the coating material can be crosslinked for the purpose of improving heat resistance and mechanical properties.
As a crosslinking method, a conventionally known crosslinked polyethylene (XLP
E) Similar to the cross-linking method used for cables (CV cables), a method of adding an organic peroxide as a cross-linking agent and causing a chemical cross-linking by heat treatment, a method of cross-linking by electron beam, ultraviolet ray, etc., a silane cross-linking method, etc. However, in view of durability and the like, crosslinking with an organic peroxide or electron beam / ultraviolet crosslinking is preferable. The cross-linking reaction is performed by heat treatment at the same time as extrusion molding, but it is preferable to perform heat treatment by nitrogen gas or the like in order to prevent deterioration of the resin. Furthermore, the cyclic olefin polymer of the present invention has a high glass transition temperature and a high melt extrusion temperature, so that when crosslinking is performed using an organic peroxide, the crosslinking reaction rate is easily controlled, as described above. It is preferable to use an organic peroxide having a high decomposition temperature described in the item (crosslinking agent).

(Foaming) As a method for foaming the wire covering material in the present invention, in addition to the above-mentioned foaming method using a conventionally known foaming agent, a gas is directly injected into a molten polymer composition during extrusion. For example, a method in which an inert gas is mixed in the form of closed cells by performing such a method can be used.

(Electric Wire) The electric wire coated with a conductor using the electric wire coating material of the present invention can be used as various electric wires. Specific examples thereof include plastic insulated wires such as power distribution wires, control / instrumentation cables, electronic device wires, and mobile cables; power cables such as insulated cables, high-voltage power cables, and plastic power cables;
In-city / out-of-city cable, intra-office cable, broadband cable,
High-frequency coaxial cables, high-frequency coaxial (pipe) feeders and elliptical waveguides, communication cables such as communication wires and cables, etc., have excellent dielectric properties, water-tree resistance,
It is particularly effective for high-voltage power cables, high-frequency coaxial cables, etc. due to its mechanical properties, bending resistance, flexibility and the like.

[0052]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Evaluation items) (1) AC breakdown voltage: The AC breakdown voltage is 97 kV / 10 min, 105 kV / 10 min based on UPT.
Thereafter, the measurement was performed under the conditions of 5 kV / 10 min. (2) Water-tree resistance: The water-tree resistance was measured by immersing various cables in hot water at 70 ° C. and applying a voltage of 1 KHz and 38 KV for 60 days. (3) Bending resistance: For evaluation of bending resistance, various cables were wound around a cylinder having a diameter of 300 mmφ and allowed to stand, and after a certain period of time, the occurrence of cracks was observed.

Example 1 (Synthesis of Cyclic Olefin Polymer) Under a nitrogen atmosphere, tricyclo [4.3.1 ^2,5 . [ ^1,6 ] deca-3,7-diene (tricyclic norbornenes, common name dicyclopentadiene, manufactured by Nippon Zeon, purity 95% by weight or more, hereinafter abbreviated as DCP) 100 parts by weight of a known metathesis ring-opening polymerization. Polymerization was carried out using a catalyst system, followed by hydrogenation in a known manner to obtain a hydrogenated DCP ring-opening polymer. This hydrogenated DCP ring-opening polymer had a number average molecular weight Mn of 41,000 as measured by GPC (gel permeation chromatography) using cyclohexane as a solvent in terms of polyisoprene. This hydrogenated product of the DCP ring-opening polymer A was dried by a known method. The hydrogenation rate before and after the hydrogenation reaction was 99.8% or more by proton NMR and the Tg measured by DSC was 97 ° C. This hydrogenated product A10
0.2 parts by weight of a phenolic antioxidant pentaerythrityl-tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) is mixed with 0 part by weight and biaxially kneaded. The strand (rod-like molten resin) was passed through a strand cutter to obtain a pellet (granular) wire covering material.

(Manufacture of Electric Wire) The obtained pellet for coating the electric wire was heated and melted by an extruder, and the outer diameter was 19 mm.
An inner semiconductor layer (1 mm thick) and a cyclic olefin polymer insulating coating layer (2
mm thickness) and an outer semiconductive layer (1 mm thickness) to produce a power cable.

(Evaluation of Characteristics) As a result of the evaluation of the production of the power cable by the above-described evaluation method, the AC breakdown voltage was 7
80 KV, water tree generation degree: 6, crack generation rate (after one month): 0%.

Example 2 (Synthesis of Cyclic Olefin Polymer) Instead of 100 parts by weight of DCP, 8-ethyl-tetracyclo [4.4.1] was used.
^2,5 . [ ^17,10.0 ] dodeca-3-ene (tetracyclic norbornenes, hereinafter abbreviated as ECD), 15 parts by weight and 85 parts by weight of DCP (100 parts by weight in total), and ETD / A DCP ring-opening copolymer hydrogenated product B was obtained. When the copolymerization ratio of each norbornene in the polymer was calculated from the composition of the residual norbornene in the solution after polymerization (by gas chromatography), ETD / DCP = 15
/ 85 was almost equal to the charge composition. This ETD / DC
The hydrogenated P-ring-opened polymer had Mn of 40,000, a hydrogenation ratio of 99.8% or more, and Tg of 105 ° C.

A power cable was manufactured in the same manner as in Example 1 except that the obtained cyclic olefin polymer hydrogenated product B was used, and the manufacture was evaluated. As a result, an AC breakdown voltage: 790 KV, water tree generation was observed. Degree: 7, crack occurrence rate (after one month): 0%.

[0059] Instead of Example 3 (Synthesis of a cyclic olefin polymer) DCP100 parts, tetracyclo [4.4.1 ^2,5. 1 ^7,10 .
0] dodeca-3-ene (tetracyclic norbornenes, hereinafter T
CD) 40 parts by weight, 1,4-methano-1,4,4
20 parts by weight of a, 9a-tetrahydrofluorene (tetracyclic norbornenes containing an aromatic ring, hereinafter abbreviated as MTF) and DC
Using P40 parts by weight (total 100 parts by weight), a TCD / MTF / DCP ring-opening copolymer hydrogenated copolymer C was obtained in the same manner as in Example 1. When the copolymerization ratio of each norbornene in the polymer was calculated from the composition of the residual norbornene in the solution after polymerization (by gas chromatography), TC
D / MTF / DCP = 40/20/40 almost equaled the charged composition. The hydrogenated TCD / MTF / DCP ring-opened polymer had Mn of 39,000, a hydrogenation rate of 99.8% or more, and Tg of 135 ° C.

A power cable was manufactured in the same manner as in Example 1 except that the above-obtained cyclic olefin polymer hydrogenated product C was used, and the production was evaluated. As a result, an AC breakdown voltage: 792 KV, water tree generation was observed. Degree: 7, crack occurrence rate (after one month): 0%.

Example 4 0.2 parts by weight of the phenolic antioxidant pentaerythrityl-tetrakis (3- (3,3)
5-di-tert-butyl-4-hydroxyphenyl) propionate), 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5-dimethylhexane-2,5-di Five parts by weight of hydroperoxide were mixed and kneaded with a twin-screw kneader, and a strand (rod-shaped molten resin) was passed through a strand cutter to obtain a pellet (granular) wire covering material. Hereinafter, as a result of producing a power cable in the same manner as in Example 1 and evaluating the production, an AC breakdown voltage: 798 KV, a water tree generation degree: 2, and a crack generation rate (after one month): 0%. .

Example 5 0.2 parts by weight of the phenolic antioxidant pentaerythrityl-tetrakis (3- (3,3) was added to 100 parts by weight of the hydrogenated product A used in Example 1.
5-di-tert-butyl-4-hydroxyphenyl) propionate), 20 parts by weight of hydrogenated styrene / butadiene / styrene / block copolymer (Tuftec H1051, manufactured by Asahi Kasei Kogyo Co., Ltd., crumb-shaped) are mixed and biaxially kneaded. The strand (rod-like molten resin) was passed through a strand cutter to obtain a pellet (granular) wire covering material.

A power cable was manufactured in the same manner as in Example 1 and the manufacture was evaluated.
6KV, water tree generation rate: 4, crack generation rate (after one month): 0%.

Comparative Example 1 (Synthesis of Cyclic Olefin Polymer) Instead of 100 parts by weight of DCP, 8-ethyl-tetracyclo [4.4.1] was used.
^2,5 . [ ^17,10.0 ] Dodeca-3-ene (ECD) (100 parts by weight) was used to obtain an ETD ring-opening copolymer hydrogenated product D in the same manner as in Example 1. This ETD ring-opened polymer hydrogenated product had a Mn of 38,000 and a hydrogenation rate of 99.
The Tg was 140 ° C. at 8% or more.

A power cable was manufactured in the same manner as in Example 1 except that the obtained cyclic olefin polymer hydrogenated product D was used, and the manufacture was evaluated. As a result, an AC breakdown voltage: 780 KV, water tree generation was observed. Degree: 6, but in the evaluation of the crack occurrence rate measurement, as a result of observing the electric wire wound around the cylinder after one week, fine cracks were generated in the cyclic olefin polymer insulating coating layer. Met.

Comparative Example 2 A power cable was manufactured in the same manner as in Example 1 except that a known crosslinked polyethylene insulating coating material was used as a wire coating material in place of the hydrogenated cyclic olefin polymer. As a result, the AC breakdown voltage was 520 KV, the degree of water tree generation was 100, and the crack generation rate (after one month) was 0%. In addition, as a result of cutting the obtained electric wire and observing the cross section, the conductor was slightly shifted from the center and was eccentric.

Example 6 A blend obtained by mixing the hydrogenated product of the ring-opened polymer A obtained in Example 1 and the crosslinked polyethylene used in Comparative Example 2 at 50:50 (weight ratio), respectively. 5 parts by weight of hydrogenated styrene / butadiene / styrene / block copolymer (Tuftec H1051, manufactured by Asahi Kasei Kogyo Co., Ltd., crumb-shaped) were further mixed as a compatibilizer with 100 parts by weight, and kneaded with a twin-screw kneader. The strand (rod-like molten resin) was passed through a strand cutter to obtain a pellet (granular) wire covering material. Hereinafter, as a result of producing a power cable in the same manner as in Example 1 and evaluating the production, an AC breakdown voltage: 710 KV and a water tree generation degree:
30, crack occurrence rate (after one month): 0%. Further, as a result of cutting the obtained electric wire and observing the cross section, there was no eccentricity of the conductor.

[0068]

According to the present invention, there is provided a wire coating material having excellent bending resistance, flexibility, workability, and mechanical properties, and a cyclic olefin polymer for the coating material. The used electric wire is provided.

Claims (3)

[Claims] 1. A repeating structural unit derived from a tricyclic norbornene monomer is present in an amount of 20 to 10 in all repeating units of the polymer.
An electric wire covering material containing 0% by weight and containing a cyclic olefin-based polymer having a number average molecular weight (Mn) of 10,000 to 100,000 in terms of polyisoprene, as measured by gel permeation chromatography. . 2. The electric wire covering material according to claim 1, wherein the cyclic olefin-based polymer is a hydrogenated product of a norbornene-based ring-opening polymer. 3. An electric wire provided with the electric wire covering material according to claim 1 on the outer periphery of a conductor.