JPH06116362A - Semiconducting resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition suitably usable as inner and outer semiconducting layers, etc., such as electric wires or power cables. CONSTITUTION:This semiconducting resin composition is obtained by blending an epoxy group-containing olefinic polymer containing 0.1-40wt.% epoxy group unit in a resin component or its composition with an epoxy curing agent and electrically conductive carbon black.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition preferably used for inner and outer semiconductive layers of electric wires, electric power cables and the like and electric power cables using the same.

[0002]

2. Description of the Related Art In a high voltage cross-linked polyethylene insulated power cable, deterioration due to corona discharge generated in a gap between a center conductor and a cross-linked polyethylene insulating layer and between a cross-linked polyethylene insulating layer and a shielding layer is prevented. To this end, inner and outer semiconductive layers are provided on the inner and outer layers of the crosslinked polyethylene insulating layer, respectively. This semiconductive layer is required to be in good contact with the crosslinked polyethylene insulating layer and have excellent surface smoothness. Therefore, in recent years, this layer and the polyethylene insulating layer are simultaneously extruded, that is, so-called multilayer coextrusion. Tends to be formed by law.

[0003]

Of the inner and outer semiconductive layers formed in this manner, the outer semiconductive layer is stripped from the crosslinked polyethylene insulating layer at the time of connecting and terminating the cable. If the adhesion between the layers is strong, the peeling work becomes difficult, and if the peeling is performed unreasonably, the cross-linked polyethylene insulating layer will be scratched, which is not preferable. Further, there is a problem in the coupling property between the filler component such as conductive carbon black and the resin component, and the addition of the organic peroxide at the time of crosslinking is accompanied by problems such as decomposition residue and odor.

[0004]

[Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned problems, as a result, the adhesiveness to the electric insulating layer and the appropriate releasability, the coupling property between the filler component and the resin component, and the crosslinking property at the time of crosslinking are obtained. As a result of intensive studies on problems such as decomposition residue and odor associated with the addition of the organic peroxide, the present invention having a remarkable effect has been reached. That is, first, the present invention relates to an epoxy group-containing olefin polymer containing 0.1 to 40% by weight of an epoxy group unit in a resin component or a composition thereof, an epoxy curing agent, a conductive carbon black, and optionally an inorganic A semiconducting resin composition containing a filler, and secondly, a power cable using the above semiconducting resin composition.

The present invention will be described in detail below. The epoxy group-containing olefin polymer of the present invention includes an olefin and an epoxy group-containing monomer obtained by high pressure radical polymerization.
Ternary or multi-component random copolymer of terpolymer or olefin with epoxy group-containing monomer and other unsaturated monomer, graft obtained by addition-modifying epoxy group-containing monomer to olefin polymer Copolymers are included. As the olefin of the epoxy group-containing olefin polymer obtained by high-pressure radical polymerization, ethylene, propylene, butene-
Examples thereof include α-olefins having 2 to 12 carbon atoms such as 1, but ethylene is particularly preferable, and ethylene 60 to
A copolymer composed of 99.9% by weight, an epoxy group-containing monomer of 0.1 to 40% by weight, and another unsaturated monomer of 0 to 39.9% by weight is preferable.

The above-mentioned epoxy group-containing monomer is preferably an unsaturated glycidyl group-containing monomer, and specific examples of the unsaturated glycidyl group-containing monomer include glycidyl acrylate, glycidyl methacrylate and itaconic acid monoester. Glycidyl ester, butene tricarboxylic acid monoglycidyl ester, butene tricarboxylic acid diglycidyl ester,
Butene tricarboxylic acid triglycidyl ester, and glycidyl esters such as α-chloroallyl, maleic acid, crotonic acid, fumaric acid, etc. or glycidyl ethers such as vinyl glycidyl ether, allyl glycidyl ether, glycidyl oxyethyl vinyl ether, styrene-p-glycidyl ether Examples thereof include p-glycidyl styrene and the like, and particularly preferable examples include glycidyl methacrylate and allyl glycidyl ether.

Other unsaturated monomers include olefins,
At least one monomer selected from vinyl esters, α, β-ethylenically unsaturated carboxylic acids or derivatives thereof, and the like are preferable, and specifically, propylene and butene-
1, hexene-1, decene-1, octene-1, styrene and other olefins, vinyl acetate, vinyl propionate, vinyl benzoate and other vinyl esters, acrylic acid, methacrylic acid methyl, ethyl, propyl, butyl, 2 -Ethylhexyl, cyclohexyl, dodecyl, octadecyl and other esters, vinyl chloride, vinyl methyl ether, vinyl ethyl ether and other vinyl ethers, and acrylic acid amide compounds, but especially vinyl acetate, (meth) acrylic acid ester,
Vinyl chloride and the like are preferable.

Specific examples of the epoxy group-containing olefin polymer include ethylene-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, ethylene-ethyl acrylate-glycidyl methacrylate copolymer, ethylene. Examples thereof include carbon monoxide-glycidyl methacrylate copolymer and ethylene-vinyl chloride-glycidyl methacrylate copolymer. Two or more kinds of these epoxy group-containing olefin (co) polymers may be mixed.

Another example of the epoxy group-containing olefin polymer of the present invention is a modified graft copolymer obtained by addition-reacting the above-mentioned epoxy group-containing monomer with an olefin homopolymer or copolymer. Examples of the olefin polymer include homopolymers of low density, medium density, high density polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, etc., ethylene-propylene copolymer, ethylene-
With other α-olefins containing ethylene as a main component, such as butene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-4-methylpentene-1 copolymer, and ethylene-octene-1 copolymer , A copolymer of propylene-ethylene block copolymer and other propylene-based α- olefins, ethylene-vinyl acetate copolymer, ethylene and acrylic acid or methacrylic acid methyl, ethyl , Copolymers with esters such as propyl, isopropyl, butyl, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, ethylene-vinyl acetate-vinyl chloride copolymer and mixtures thereof. .

In the present invention, the olefin polymer containing an epoxy group may be blended with another olefin polymer.
The resin composition contains 0.1 to 40 epoxy group monomer units.
It is essential that the content be wt%. Other olefin polymers include homopolymers such as ultra low density polyethylene, linear low density polyethylene, low density, medium density, high density polyethylene, polypropylene, polybutene-1, and poly-4-methylpentene-1. Ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, copolymer of ethylene and ester of acrylic acid or methacrylic acid such as methyl, ethyl, propyl, isopropyl and butyl, ethylene-vinyl acetate-vinyl chloride copolymer Examples thereof include olefin polymers such as polymer and ethylene-ethyl acrylate-vinyl chloride copolymer. You may use these in mixture of 2 or more types.

As the epoxy curing agent used in the present invention, an appropriate epoxy curing agent is used, and one or more of an acid group-containing compound, an amino group-containing compound, an isocyanate group-containing compound or one or more of these compounds. A (co) polymer of olefin and olefin / addition-modified graft copolymer is preferably used.

Examples of the acid group-containing compound include C1 to C20 or higher saturated aliphatic carboxylic acids, or C1 to C
20 or more unsaturated aliphatic carboxylic acids, or C1-C20 or more aromatic carboxylic acids, or mixtures thereof, such as formic acid, acetic acid, butyric acid, maleic acid, itaconic acid, fumaric acid, benzoic acid, palm Fatty acids extracted from vegetable oils such as oil, animal oils such as whale oil and cow oil, lauric acid, palmitic acid, stearic acid, oleic acid, etc., but compounds containing two or more carboxyl groups in the molecule, such as malic acid , Sebacic acid, succinic acid, adipic acid, thiodipropionic acid, citraconic acid,
Citric acid and the like are preferable, and DL-malic acid and sebacic acid are particularly preferable.

Copolymers of acid group-containing compounds and olefins, acid-modified polymers such as acid-modified polyethylene and acid-modified polypropylene, and acid-modified wax can also be used. Specific examples thereof include ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-crotonic acid copolymer, ethylene-maleic anhydride copolymer, maleic anhydride-modified polyethylene, ethylene-ethyl acrylate copolymer. Examples thereof include thermal decomposition products of polymers.

Examples of the amino group-containing compound include C1 to C2
0 or more saturated aliphatic amines, C1 to C20 or more unsaturated aliphatic amines, C1 to C20 or more aromatic amines such as methylamine, propylamine, stearylamine, 1,6 hexadiamine, Trioctaamine, aniline, 2ethylaniline, etc., and aliphatic amines such as diethylenetriamine, triethylenetetramine, diethylaminopropylamine, menthenediamine, isophoronediamine, bis (4-amino-3-methylcyclohexyl) methane, N
A cycloaliphatic polyamine such as aminoethylpiperazine,
Aliphatic polyamines containing aromatic rings such as metaxylenediamine, aromatics such as polyethyleneimine having primary, secondary and tertiary amine nitrogen in one molecule, metaphenylenediamine, methylenedianiline, diaminodiphenylsulfone Polyamines, aliphatic polyamines containing the above aliphatic polyamines and aromatic rings, known modification methods of polyamine compounds such as aromatic polyamines, for example, addition reaction with epoxy compounds, acrylonitrile, Michael addition reactions such as acrylic acid esters, and methylol compounds. Modified polyamine produced by the Mannich reaction, etc., 2-methylimidazole, 2-ethyl-4-methylimidazole,
Examples thereof include imidazole compounds such as 1-cyanoethyl-2-methylimidazole, tertiary amines such as trisdimethylaminophenol, tri-2-ethylhexyl acid salt of trisdimethylaminomethylphenol, and the like.

Examples of the isocyanate compound include toluylene diisocyanate, naphthylene 1,5-diisocyanate, o-toluylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate and the like. A blocked isocyanate obtained by blocking hexamethylene diisocyanate, hydrogenated xylene diisocyanate, isophorone diisocyanate and the like with ε-caprolactam, phenols and alcohols is particularly preferable. When a blocked isocyanate is used, it is preferable to add amines or metal soap as a dissociation catalyst depending on molding conditions. Two or more of these epoxy curing agents may be mixed and used, and the blending amount is determined by the degree of crosslinking required for the crosslinked molded article.

The preferable blending amount of the conductive carbon black is 20 to 100 parts by weight. If the blending amount is less than 20 parts by weight, the conductivity will be insufficient, and if it exceeds 100 parts by weight, the extrusion processability will be poor, so that neither can be put to practical use.

Further, in the present invention, it is preferable to mix an inorganic filler. Examples of the inorganic filler include conventional fillers such as aluminum silicate, magnesium silicate, kaolin, clay, mica and talc. Especially aluminum silicate, magnesium silicate,
Talc is preferable, and the compounding amount of these fillers is preferably 5 to 50 parts by weight. If the content is less than 5 parts by weight, the releasability from the coating will be insufficient, and if it exceeds 50 parts by weight, the extrudability will be deteriorated, which is not preferable.

A lubricant such as a higher fatty acid, a higher alcohol, a metal soap or the like may be added to the composition of the present invention in order to further improve the releasability from the coated body and the extrusion processability of the composition. You may add general additives, such as an antioxidant, a ultraviolet absorber, and a pigment, in the range which does not impair the objective of the invention.

As a concrete example of the use of the composition of the present invention, two layers are coextruded with the material of the crosslinked polyethylene insulating layer, or three layers are coextruded with the inner semiconductive layer and the insulating layer and then heated to crosslink. And may be used as a crosslinked inner / outer semiconducting layer of a power cable. In this case, the composition of the present invention adheres well to the insulating layer, has good surface properties (smoothness), and is simultaneously cross-linked in the cross-linking step at the same time, and therefore has excellent electrical properties and mechanical strength. It becomes a conductive layer, and can be completely and easily peeled off without adhering to or remaining on the cable end or the insulating layer during contact treatment.

[0020]

EXAMPLES Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the invention. The composition shown in Table 1 was co-extruded on a conductor together with the composition for an insulating layer made of crosslinkable polyethylene, and then 1
A peeling strength (A) when a cross-linked insulated power cable is manufactured by cross-linking in a heating furnace at 80 ° C for 10 minutes and the outer semiconductive layer is peeled off (A
According to EIC), the quality of the insulator surface after stripping off the outer semiconductive layer, and the volume resistivity of the outer semiconductive layer were measured.
The results are shown in Table 1. The resins used are as follows. E-GMA: ethylene-glycidyl methacrylate copolymer (GMA = 25% by weight) E-VA-PVC: ethylene-vinyl acetate-vinyl chloride copolymer (Sumigraft GF manufactured by Sumitomo Chemical Co., Ltd.) E-GMA-VA: ethylene- Glycidyl methacrylate-vinyl acetate copolymer (GMA = 5% by weight, VA = 2
0% by weight) MAnEEA: Maleic anhydride grafted ethylene-ethyl acrylate copolymer (addition amount of maleic anhydride 0.36)
% By weight, MFR = 1.0 g / 10 minutes) Isocyanate: Blocked isocyanate (Desmodur, CT stable, manufactured by Sumitomo Bayer Urethane Co., Ltd.) In the examples, 1 part of stearic acid, 2 parts of triethylenediamine and 2 parts of zinc to the resin component. Was added.

[0021]

[Table 1]

From the results of Examples 1 to 5 and Comparative Examples 1 and 2 described above, the external semiconductive layer obtained by using the composition of the present invention was easier to peel from the insulating layer than the conventional semiconductive layer. It turns out that In addition, in Examples 1 to 5, carbon particles did not remain on the surface of the insulating layer.

[0023]

The semiconductive resin composition of the present invention is provided as an inner and an outer semiconductive layer of a crosslinked polyethylene insulating layer, and is a corona generated in a void formed between the crosslinked polyethylene insulating layer and the shielding layer. Prevents deterioration due to discharge, has appropriate adhesion and peelability with the cross-linked polyethylene insulation layer, and the external semiconductive layer does not cause excessive peeling from the cross-linked polyethylene insulation layer during cable connection and terminal treatment. Therefore, the crosslinked polyethylene insulating layer has excellent surface smoothness without causing scratches. Also, the coupling effect between the resin and the filler is good, and no organic peroxide is used, so there is no trouble of decomposition residue or odor.

Claims (2)

[Claims] 1. An epoxy group unit of 0.1 to 4 in a resin component.
A semiconductive resin composition comprising an epoxy group-containing olefin polymer containing 0% by weight or a composition thereof and an epoxy curing agent and conductive carbon black. 2. A power cable comprising the semiconductive resin composition according to claim 1 as an inner and / or outer semiconductive layer.