JP2001167634A - Peelable, semi-conductive resin composition for, outer semi-conductive layer of chemically cross-linked polyethylene insulating power cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition and a chemically cross-linked polyethylene insulating power cable manufactured using the same, which satisfies conditions required in an outer semi-conductive layer of a power cable having a chemically cross-linked polyethylene as an insulating layer. SOLUTION: Disclosed herein is a chemically cross-linked polyethylene insulating power cable in which an inner semi-conductive layer, a chemically cross- linked polyethylene insulating layer, an outer semi-conductive layer and a jacket layer are formed on a conductor in sequence. In this power cable, the outer semi-conductive layer is formed from a peelable semi-conductive resin composition, which comprises (a) at least one selected from specific ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers and ethylene-butyl acrylate copolymers, (b) specific straight-chain ethylene-α-olefin copolymers, (c) specific polypropylenes, (d) specific organopolysiloxane, (e) carbon blacks, and (f) organic peroxides, the respective components being contained by a specific amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a peelable semiconductive resin composition used as an outer semiconductive layer of a chemically crosslinked polyethylene insulated power cable, and a chemically crosslinked polyethylene insulation obtained by coating the composition on a chemically crosslinked polyethylene insulating layer. Regarding power cables.

[0002]

2. Description of the Related Art An ordinary chemically cross-linked polyethylene insulated power cable has a conductor, an inner semiconductive layer,
Consists of an insulating layer, an outer semiconductive layer, and a jacket layer.The outer semiconductive layer is corona-degraded due to external bends, partial exfoliation from the chemically cross-linked polyethylene insulating layer due to heat cycles, and the generation of voids. Further, in order to prevent other insulation deterioration, the conductivity is set to a low product specific resistance value of about 100 Ω · cm. The external semiconductive layer has the above-described volume specific resistance value, and has good adhesion with the chemically crosslinked polyethylene insulating layer, and bends from the outside and follows a heat cycle,
To prevent partial exfoliation and voids, it is flexible and has good adhesion to chemically cross-linked polyethylene, and does not decrease mechanical strength, elongation, flexibility, and processability despite filling with a large amount of carbon black. A polymer is required, and ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ionomer, acid-modified polyethylene and the like have been conventionally used as typical ones. However,
When connecting chemically cross-linked polyethylene insulated power cables to each other, the outer semiconductive layer must be peeled off from the chemically cross-linked polyethylene insulated layer to facilitate the terminal processing work. It must be a good external semiconductive layer.

[0003] The above-mentioned ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ionomer, acid-modified polyethylene and the like have good adhesiveness, but have insufficient heat resistance and the like. Therefore, a peelable semiconductive resin composition conventionally used for an external semiconductive layer of a power cable by a chemical crosslinking method is disclosed in, for example, JP-A-58-212007.
JP-A-59-230205, JP-A-60-189
No. 110, JP-A-62-258518, JP-A-62-1
No. 17202, JP-A-63-89552, JP-A-3-
Many proposals have been made in JP-A-29210 and JP-A-3-247641. However, the peelability, heat resistance, high-temperature extrusion processability, etc. are insufficient, the mechanical strength, elongation, cold resistance, etc. are poor, and the external semiconductive material has peelability and adhesion that satisfy all conditions There was no layer resin composition and no power cable made therefrom.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a resin composition which satisfies the following conditions required as an outer semiconductive layer of a power cable in which an insulating layer is composed of chemically crosslinked polyethylene, and a chemically crosslinked polyethylene produced using the same. To provide an insulated power cable. (1) The resin composition for an external semiconductive layer is semiconductive and has a volume specific resistance of 100 Ω · cm or less. (2) When the power cable is bent or subjected to a heat cycle, the elongation percentage is 100% or more in order to maintain flexibility and elongation so as not to cause partial peeling or voids from the chemically crosslinked polyethylene insulating layer. . (3) The interface between the chemically cross-linked polyethylene insulating layer and the outer semiconductive layer is smooth and has no fine protrusions. (4) When the outer semiconductive layer is peeled off, the outer semiconductive layer itself does not cut with a weak tensile force.
Pa or more. (5) Cold resistance. (6) When the outer semiconductive layer is peeled off from the chemically cross-linked polyethylene insulating layer, the outer semi-conductive layer is cut with a relatively weak force using a knife, so that the cutting operation can be easily performed without damaging the chemically cross-linked polyethylene layer. , And can be easily peeled off,
The peel strength between the interface with the chemically cross-linked polyethylene insulating layer is 4 kg / 0.5 inch or less so that no residue or scratch remains on the surface of the chemically cross-linked polyethylene layer after peeling. (7) Even if crosslinking with an organic peroxide is not performed, 120
Heat deformation rate at 120 ° C is 40% or less due to heat resistance against heat deformation at 0 ° C.

[0005]

The present inventors have selected various polymers and compounding agents in order to develop a resin composition satisfying the necessary conditions for the above-mentioned outer semiconductive layer, and have selected these in a specific amount. Numerous experiments have demonstrated that the subject of the present invention can be solved only when blended, and completed the present invention.

That is, the first invention of the present invention relates to a chemically crosslinked polyethylene insulation in which an inner semiconductive layer, a chemically crosslinked polyethylene insulating layer, an outer semiconductive layer and a jacket layer are formed on a conductor from inside to outside. The following (a), (b), (c), which are used as an outer semiconductive layer of a power cable,
A releasable semiconductive resin composition comprising components (d), (e) and (f). (A) (I) an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 50% by weight and a melt mass flow rate of 1.0 to 100.0 g / 10 minutes, and (II) an ethyl acrylate content of 10 to 50% by weight. Ethylene-ethyl acrylate copolymer having a melt mass flow rate of 1.0 to 100.0 g / 10 min, and (III) a butyl acrylate content of 10 to 50% by weight, and a melt mass flow rate of 1.0 to 100.0 g / 10 min. At least one selected from ethylene-butyl acrylate copolymers
00 parts by weight (b) Melt mass flow rate 0.1 to 30.0 g / 1
0 minute, 55 to 200 parts by weight of a linear ethylene-α-olefin copolymer having a density of 0.870 to 0.944 g / cm ³ (c) Melt mass flow rate 0.5 to 30.0 g / 1
0 min, 5 to 50 parts by weight of polypropylene having a density of 0.900 to 0.920 g / cm ³ (d) The following formula (A)

Embedded image (Wherein, R ¹ is an aliphatic unsaturated hydrocarbon group, R ² is an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group,
0 ≦ x <1, 0.5 <y <3, 1 <x + y <3, 0 <a
≦ 1, 0.5 ≦ b ≦ 3. 0.5 to 50 parts by weight of an organopolysiloxane represented by the formula (e): 10 to 400 parts by weight of carbon black (f) 0 to 2.0 parts by weight of an organic peroxide.

A second invention of the present invention provides a resin composition for an internal semiconductive layer on a conductor, a resin composition for a chemically crosslinkable polyethylene insulating layer, and a peelable semiconductive resin composition of the first invention. The step of coating the resin composition for the internal semiconductive layer and the resin composition for the chemically cross-linkable polyethylene insulating layer is performed by a two-layer co-extrusion apparatus, and then the releasable semiconductive resin is coated. A method for producing a chemically crosslinked polyethylene insulated power cable, comprising performing a step of coating a composition.

[0008] In a third aspect of the present invention, a resin composition for an internal semiconductive layer, a resin composition for a chemically cross-linkable polyethylene insulating layer, and the above-mentioned releasable semiconductive resin composition are sequentially coated on a conductor. The method is a method for producing a chemically crosslinked polyethylene insulated power cable, wherein the step of performing is performed by a three-layer coextrusion apparatus.

Further, the fourth invention of the present invention is directed to the second invention.
Alternatively, it is a chemically crosslinked polyethylene insulated power cable manufactured according to the third invention.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

1. Conductor and Internal Semi-Conducting Layer The conductor and the internal semi-conducting layer used in the present invention may be any as long as they are usually used in chemically crosslinked polyethylene insulated wires. Among them, as the conductor, for example, a conductor made of soft copper, semi-hard copper, hard copper, aluminum, or the like, a stranded conductor, or the like is preferable. Also, as the internal semiconductive layer,
For example, those obtained by blending carbon black or the like with a polyethylene copolymer such as an ethylene-vinyl acetate copolymer or an ethylene-ethyl acrylate copolymer are preferable. The reason polyethylene copolymers are preferred for the inner semiconductive layer is that a large amount of carbon black must be blended in order to make the inner semiconductive layer semiconductive. This is because they are superior in miscibility and dispersibility with carbon black and excellent in adhesion to conductors and insulating layers, as compared with the above resin. The role of the inner semiconductive layer is to improve the electric potential tendency and make the electric potential the same, thereby improving the withstand voltage performance. As a result, the life of the outdoor electric wire is prolonged.

As the carbon black compounded for the internal semiconductive layer, conductive carbon black, acetylene black, Ketjen black and the like can be used. The amount of the carbon black is 8 to 350 parts by weight based on 100 parts by weight of the polyethylene copolymer.
Parts by weight. If the compounding amount of carbon black is less than 8 parts by weight, even if Ketjen black having good conductivity is used, the conductive performance is insufficient. On the other hand, if the compounding amount of carbon black exceeds 350 parts by weight, economical efficiency is low. In addition, the extrudability and the surface properties are deteriorated, which is not desirable.

2. Chemically Crosslinked Polyethylene Insulation Layer The chemically crosslinked polyethylene insulation layer used in the present invention is a method in which a polyethylene resin, an organic peroxide, an antioxidant, and the like are charged into an insulating layer extruder (before the charge, the organic peroxide is added to the polyethylene resin. Or a pre-soaked antioxidant, or a masterbatch of a polyethylene resin and an organic peroxide or an antioxidant.), 110 in an extruder.
It is heated and kneaded at ~ 150 ° C, extruded from a die, and heated to 200 ~ 350 ° C in a crosslinking tube to form a chemically crosslinked polyethylene insulating layer.

The polyethylene resins include high-pressure low-density polyethylene, high-density polyethylene, medium-density polyethylene, linear low-density ethylene-α-olefin copolymer, and linear ultra-low-density ethylene-α-olefin copolymer. Polymer, ethylene-α- produced by metallocene catalyst
Olefin copolymers and the like can be mentioned.

Examples of the organic peroxide include dicumyl peroxide, di-t-butyl peroxide, 2,5
-Di (peroxybenzoate) hexin-3 and the like are used. The amount of organic peroxide used is polyethylene resin 1.
0.01 to 10.0 parts by weight based on 00 parts by weight is preferred.

Examples of the antioxidant include a phenolic antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant and the like, and about 0.001 to 5 parts by weight based on 100 parts by weight of the polyethylene resin. Used.

3. External semiconductive layer (1) Components of peelable semiconductive resin composition The peelable semiconductive resin composition for an external semiconductive layer of the present invention comprises:
It comprises the following components (a) to (g). (A) (I) ethylene-vinyl acetate copolymer, (II)
Ethylene-ethyl acrylate copolymer, and (II)
I) One or more components selected from ethylene-butyl acrylate copolymer (I) Ethylene-vinyl acetate copolymer The ethylene-vinyl acetate copolymer used in the present invention has a vinyl acetate content of 10 to 10. 50% by weight, preferably 15 to 50%
% By weight, melt mass flow rate 1.0 to 100.0 g
/ 10 min. Vinyl acetate content is 10% by weight
If it is less than 1, peeling property, flexibility, elongation, carbon black filling property will be deteriorated, interface state, workability, etc. will be deteriorated, water tree and electric tree will be generated from the interface, and the life of the power cable will be shortened, which is not desirable. , More than 50% by weight, the tensile strength is weakened, the peeling operation is not successful, and the cable manufactured using this is not desirable because the surfaces stick together. Further, the melt mass flow rate is 1.0 g / 1.
If the time is less than 0 minutes, the workability, flexibility, elongation, etc. are insufficient, and if it exceeds 100.0 g / 10 minutes, the tensile strength, heat resistance, etc. deteriorate, which is not desirable.

(II) Ethylene-ethyl acrylate copolymer component The ethylene-ethyl acrylate copolymer used in the present invention has an ethyl acrylate content of 10 to 50% by weight, preferably 15 to 40% by weight, and a melt mass flow rate of 1.
It has a characteristic of 0 to 100.0 g / 10 minutes. When the content of ethyl acrylate is less than 10% by weight, the peeling property, flexibility, elongation, and carbon black filling property are deteriorated, the interface state, workability, etc. are deteriorated. However, the ethylene-ethyl acrylate copolymer exceeding 50% by weight has no physical problem, but is extremely difficult to produce. Further, if the melt mass flow rate is less than 1.0 g / 10 minutes, workability, flexibility, elongation, etc. are insufficient, and if it exceeds 100.0 g / 10 minutes, tensile strength, heat resistance, etc. become poor. Not desirable.

(III) Ethylene-butyl acrylate copolymer component The ethylene-butyl acrylate copolymer used in the present invention has a butyl acrylate content of 10 to 50% by weight, preferably 15 to 40% by weight, and a melt mass flow rate of 1.
It has a characteristic of 0 to 100.0 g / 10 minutes. When the butyl acrylate content is less than 10% by weight, the peeling property, flexibility, elongation, and carbon black filling property are deteriorated, the interface state, workability, and the like are deteriorated. The ethylene-butyl acrylate copolymer having an undesirably short life time and exceeding 50% by weight has no physical problem but is extremely difficult to produce. Further, if the melt mass flow rate is less than 1.0 g / 10 minutes, workability, flexibility, elongation, etc. are insufficient, and if it exceeds 100.0 g / 10 minutes, tensile strength, heat resistance, etc. become poor. Not desirable. As the component (a) of the present invention, the above-mentioned (I) ethylene-vinyl acetate copolymer, (I)
I) Ethylene-ethyl acrylate copolymer and (I)
II) One selected from ethylene-butyl acrylate copolymer alone or a blend of one or more can be used.

(B) Linear ethylene-α-olefin copolymer component The component (b) has a melt mass flow rate of 0.1 to 30.
0 g / 10 min, density 0.870 to 0.944 g / cm ³
Of a linear ethylene-α-olefin copolymer of
It imparts properties to the external semiconductive layer that can withstand a dynamic deformation test of not less than ℃, and enables the external semiconductive layer to be extruded at a high temperature. The melt mass flow rate of the component (b) is 0.
If the amount is less than 1 g / 10 minutes, the processability deteriorates, and 30.
If it exceeds 0 g / 10 minutes, the tensile strength becomes weak, which is not desirable. On the other hand, if the density is less than 0.870 g / cm ³ , the composition cannot withstand a heat deformation test at 120 ° C. or more, and if the density exceeds 0.944 g / cm ³ , it is not desirable because of lack of flexibility. Component (b) is used in an amount of 55 to 200 parts by weight, preferably 75 to 150 parts by weight, per 100 parts by weight of component (a). (B) The amount of the component used is 55
If the amount is less than 10 parts by weight, the external semiconductive layer cannot withstand the heat deformation test at 120 ° C., and if it is more than 200 parts by weight, the flexibility, elongation and carbon black filling property are undesirably deteriorated.

Examples of the linear ethylene-α-olefin copolymer as the component (b) include ethylene-α-olefin copolymers produced with a multi-site catalyst or a single-site catalyst. As the α-olefin, propylene, butene-1, hexene-1, 4-methyl-pentene-1, octene-1, nonene-1, decene-1 and the like are selectively used.

(C) Polypropylene Component The component (c) has a melt mass flow rate of 0.5 to 30.
0 g / 10 min, density 0.900 to 0.920 g / cm ³
Used to impart heat resistance and releasability to the outer semiconductive layer. If the melt mass flow rate of the component (c) is less than 0.5 g / 10 min, the processability is poor, and if it exceeds 30.0 g / 10 min, the tensile strength becomes weak, which is not desirable. Further, the density is 0.900 g / cm ³
If the ratio is less than 0.9, the heat resistance deteriorates, which is undesirable.
If it exceeds 20 g / cm ³ , the flexibility becomes poor, which is not desirable. Component (c) is used in an amount of 5 to 50 parts by weight, preferably 15 to 30 parts by weight, per 100 parts by weight of component (a). If the amount of the component (c) is less than 5 parts by weight, heat resistance and releasability will be insufficient, and if it exceeds 50 parts by weight, flexibility, cold resistance, and carbon black filling property will deteriorate, which is not desirable. The polypropylene used in the present invention may be a propylene homopolymer or a copolymer of propylene and ethylene or another olefin as long as it has the above-mentioned physical properties.

(D) Organopolysiloxane Component The component (d) has the following formula (A)

[0024]

Embedded image (Wherein, R ¹ is an aliphatic unsaturated hydrocarbon group, R ² is an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group,
0 ≦ x <1, 0.5 <y <3, 1 <x + y <3, 0 <a
≦ 1, 0.5 ≦ b ≦ 3. ). In the organopolysiloxane represented by the formula (A), R ¹ is, for example, a vinyl group, an allyl group, an acryl group, a methacryl group, etc., and R ² is a methyl group, an ethyl group, a propyl group, etc. Alkyl group, phenyl group, aryl group such as tolyl group, cycloalkyl group such as cyclohexyl group and cyclobutyl group, and hydrogen partially bonded to carbon atom of these hydrocarbon groups such as halogen atom, cyano group, mercapto group, etc. And the like, and these may be the same or different combinations thereof. Also, a
When the value is 0, the reaction with the ethylene-based resin does not occur, which is not desirable. When it exceeds 1, the composition of the present invention becomes too hard, and the flexibility and processability decrease, which is not desirable. b is 0.
It is necessary to be 5 or more and 3 or less, preferably 1 or 2. If y is 0.5 or less, kneading of the composition of the present invention is difficult, resulting in poor processability. If y is 3 or more, the cable produced from the composition of the present invention becomes too hard, which is not desirable.

The molecular structure of the organopolysiloxane used in the present invention may be any of linear, branched, cyclic, network, and three-dimensional networks as long as it falls within the range of the formula (A). Good, but a chain is preferred. Although the degree of polymerization of this organopolysiloxane is not particularly limited,
A degree of polymerization that does not hinder kneading with the ethylene resin is required, and a degree of polymerization of 250 or more is desirable. Examples of the organopolysiloxane used in the present invention include so-called silicone gum stock which is commercially available as a tear strength improver for silicone rubber. The linear organopolysiloxane used in the present invention has the following formula (B)

[0026]

Embedded image (Wherein, R represents an unsubstituted or substituted monovalent hydrocarbon group,
n represents a number of 10 or more. ) And generally called silicone oil. R in the formula is a group selected from an alkyl group, an aryl group, and hydrogen;
Methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, phenyl group and hydrogen are typical, but all groups are the same group. Or a part of R may be another group, and a part of R may be a vinyl group or a hydroxyl group. n is 10-1
0000, and preferably 100 to 1000. If n is less than 10, kneading with polyethylene is difficult,
If n exceeds 10,000, molding becomes difficult, which is not desirable.

The viscosity at 23 ° C. of the organopolysiloxane polymer of the formula (B) used in the present invention is 10 c
St or more, preferably 1,000 to 1,000,000
The one of cSt is desirable. When the viscosity is less than 10 cSt, it is difficult to knead by heating, and the organopolysiloxane polymer may ooze out from the surface of the molded article. The amount of the organopolysiloxane used is 0.5 to 50 parts by weight, preferably 2.0 to 50 parts by weight, per 100 parts by weight of the component (a).
Parts by weight, more preferably 2.0 to 10 parts by weight.
If the amount of the organopolysiloxane is less than 0.5 parts by weight, no releasability will be exhibited, and if it exceeds 50 parts by weight, workability, tensile strength and the like will be reduced, which is not desirable.

(E) Carbon black component The component (e) is carbon black, for example, furnace black, acetylene black and Ketjen black, among which Ketjen black is particularly desirable. Ketchen Black is a Dutch AKZO
A highly conductive carbon black developed by NOBEL. There are two types, Ketjen Black EC and Ketjen Black EC600JD. Ketjen Black EC is 1/2 to that of conventional conductive carbon black. Since equivalent conductivity can be obtained with the addition amount of 1/3, the tensile strength, workability, flexibility,
It is possible to provide a semiconductive resin composition of good quality with little decrease in conductive performance due to kneading without greatly affecting physical properties such as elongation and smoothness at an interface. The amount of the carbon black to be used is 10 to 400 parts by weight, preferably 10 to 350 parts by weight, more preferably 40 to 300 parts by weight, based on 100 parts by weight of the component (a). If the amount of carbon black used is less than 10 parts by weight, the volume specific resistance required for the external semiconductive layer of the power cable is 100 Ω · cm or more, which is not desirable. If the amount exceeds 400 parts by weight, tensile strength, workability, flexibility, elongation, etc. are deteriorated, which is not desirable.

(F) Organic peroxide component The component (f) is an organic peroxide having an (OO) bond in the molecule and having a half-life temperature of 100 to 220 ° C for 10 minutes. preferable. The organic peroxide grafts resin components such as an ethylene-vinyl acetate copolymer, a linear / ethylene-α-olefin copolymer, polypropylene and an organopolysiloxane to each other, and fills and disperses carbon black. The present invention improves the tensile strength and heat resistance of the external semiconductive layer. In the present invention, there is an effect that the external semiconductive layer can be peeled off without being cut when peeled. Examples of the organic peroxide include the following. However, the value in parentheses is the decomposition temperature (° C.). Succinic peroxide (110), benzoyl peroxide (110), t-butylperoxy-2-ethylhexanoate (113), p-chlorobenzoyl peroxide (115), t-butylperoxyisobutyrate (115) ), T-butyl peroxyisopropyl carbonate (135), t-butyl peroxyurearate (140), 2,5-dimethyl-2,5
-Di (benzoylperoxy) hexane (140), t
-Butylperoxyacetate (140), di-t-butyldiperoxyphthalate (140), t-butylperoxybenzoate (145), dicumyl peroxide (150), 2,5-dimethyl-2,5- Di (t-butylperoxy) hexane (155), t-butylcumyl peroxide (155), t-butylhydroperoxide (158), di-t-butylperoxide (16)
0), 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 (170), di-isopropylbenzene hydroperoxide (170), p-menthane hydroperoxide (180), , 5-dimethylhexane-2,5-dihydroperoxide (213), cumene hydroperoxide (149). Among them, dicumyl peroxide, 2,5-dimethyl-2,5 (t-butylperoxy) hexane, cumene hydroperoxide and the like are desirable.

The amount of the organic peroxide to be used is as follows:
0 to 2.0 parts by weight with respect to 0 parts by weight. Since an organic peroxide promotes a graft reaction between polymers, when a shear stress is applied at a high temperature for a long time, radicals are generated in a mechanochemical manner. However, when added in a large amount, there is a disadvantage that scorch, burns, etc. occur, so that the use of an organic peroxide in a range of 2.0 parts by weight or less causes a graft reaction even at a relatively low temperature in a short time, and It is desirable because an external semiconductive layer of good quality can be formed without generating scorch or burns. If the amount of the organic peroxide exceeds 2.0 parts by weight, a cross-linking reaction occurs simultaneously even when grafting is performed at a low temperature, a gel is generated, and an external semiconductive layer having a smooth surface cannot be obtained. Trees and electric trees are generated, which shortens the life of the power cable, which is not desirable.

(G) Other components In the present invention, (a), (b), (c),
If necessary other than the components (d), (e) and (f),
(G) As other components, a crosslinking aid, an antioxidant, a processing aid or the like may be used.

(2) Production of resin composition The components (a), (b), (c), (e), (f) and, if necessary, the component (g) are grafted in the following order and combination, for example. It can be produced by performing reaction, blending, soaking, and the like. (A) (a) and (d) are heated and kneaded at a high temperature (220 ° C.) to form a graft of (a) and (d), which is then mixed with (b), (c), (e) and (f). ) Is fed into an extruder for producing an external semiconductive layer. (B) Using (a) and (d) at a low temperature (160 ° C.) using the organic peroxide of (f), a graft of (a) and (d) is prepared. c), (e) and (g) are charged into an extruder for producing an external semiconductive layer. (C) (a), (b), (c), (d) and (f) are heated and kneaded at a low temperature (165 ° C.) to form an intergraft of polymers, and this is mixed with (e), (f) ) Is fed into an extruder for producing an external semiconductive layer. (D) soaking (a) and (f), (b),
(C), (d) and (e) are mixed in a high concentration in (a), and a masterbatch is mixed in a high concentration in (a). Put it in the machine.

4. Jacket Layer The jacket layer of the chemically crosslinked polyethylene insulated power cable of the present invention is usually formed by extrusion-coating a polyvinyl chloride resin composition on an outer semiconductive layer. The jacket layer is formed by extruding the inner semiconductive layer, the chemically cross-linked polyethylene insulating layer, and the outer semiconductive layer by tandem extrusion or three-layer extrusion, and then extrusion-coating the polyvinyl chloride resin composition thereon.

5. Chemically crosslinked polyethylene insulated power cable The chemically crosslinked polyethylene insulated power cable of the present invention comprises, on a conductor, a resin composition for an inner semiconductive layer, a resin composition for a chemically crosslinkable polyethylene insulating layer, and an outer peelable semiconductive resin composition. It can be made by a step of sequentially coating. For this, the resin composition for the internal semiconductive layer and the resin composition for the chemically crosslinkable polyethylene insulating layer are simultaneously extruded and coated in two layers by a two-layer coextrusion apparatus, and then the external peelable semiconductive resin composition is coated. A tandem method of coating and heat-crosslinking at 200 to 350 ° C. to form a chemically crosslinked polyethylene insulating layer, or a resin composition for an internal semiconductive layer, a resin composition for a chemically crosslinkable polyethylene insulating layer, and an external peelable semiconductive The three-layer coextrusion apparatus simultaneously extrudes and coats the three-layered resin composition, for example, sends it to a cross-linking tube and causes a heat cross-linking reaction at 200 to 350 ° C. to form a chemically cross-linked polyethylene insulating layer. It is then made by extrusion coating the jacket layer.

[0035]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. In addition, the test method in an Example is as follows. (1) Interface smoothness: The interface between the chemically crosslinked polyethylene insulating layer and the external semiconductive layer was visually judged. (2) Heat deformation ratio of outer semiconductive layer: 12 of outer semiconductive layer
The heat resistance at 0 ° C. was measured by the following method in accordance with the heating deformation test method of JISC3005. (A) Preparation of test piece The resin composition for an external semiconductive layer was heated and kneaded at 180 ° C., and a sheet having a thickness of 2 mm and a size of 150 mm × 180 mm was formed by a hot press molding machine, and punched into a width of 15 mm and a length of 30 mm.
A test piece was used. (B) Measurement method A test piece was placed on a semicircular portion of a semicircular rod having a diameter of 5 mm, a parallel plate was placed on the test piece, and placed in an oven at 120 ° C. for 30 minutes.
After heating for 2 minutes, a pressure of 2 kg was applied from above the parallel plate to 3
After a lapse of 0 minutes, the thickness of the test piece was measured, and the rate of decrease in thickness was measured. (3) Peeling test of the outer semiconductive layer: It was carried out by the following method. (A) Preparation of test piece The chemically crosslinkable polyethylene resin composition was heated with a hot press machine (180 ° C., 30 minutes) to a thickness of 1.5 mm and a length of 150 m.
m, a crosslinked sheet having a width of 180 mm was obtained. On the other hand, the resin composition for an external semiconductive layer was heated and kneaded at 180 ° C., and was 2.0 mm thick, 150 mm long and 180 mm wide by a hot press molding machine.
Sheet was obtained. Both sheets were heated at 180 ° C, 15MP
A 3 mm sheet was integrated by the pressure of a. A test piece having a width of 12.7 mm and a length of 120 mm was punched out of the two-layer sheet to obtain a test piece. (B) Test method Using a tensile tester, perform a peeling test at a pulling speed of 200 mm / min at 23 ° C. and determine the peel strength at which the external semiconductive layer is peeled at an angle of 180 ° C. with respect to the chemically crosslinked polyethylene layer. (Kg / 0.5 inch). (4) Tensile strength of the outer semiconductive layer: The resin composition for the outer semiconductive layer is heated and kneaded at 180 ° C., and a sheet having a thickness of 2.0 mm, a length of 150 mm, and a width of 180 mm is obtained by a hot press molding machine. Using the test piece, the tensile strength was measured in accordance with JIS K-6760. (5) Elongation of outer semiconductive layer: Elongation was measured according to JIS K-6760 using a test piece used for tensile strength. (6) Gel fraction of chemically crosslinked polyethylene insulating layer: A sample was taken from the chemically crosslinked polyethylene insulating layer, immersed in xylene at 110 ° C. for 24 hours, and the extraction residue was determined as the gel fraction. (7) Extrusion processability: The melt mass flow rate of the resin composition for the outer semiconductive layer was measured at a temperature of 190 using a melt indexer.
The melt mass flow rate was measured and evaluated under the conditions of ° C and a load of 21.6 kg (JIS K-6760). (8) Volume resistivity: The volume resistivity of the resin composition for an external semiconductive layer was measured by the method of JIS K-6723.

Example 1 (A) Preparation of resin composition for internal semiconductive layer High-pressure ethylene-vinyl acetate having a vinyl acetate content of 28% by weight, a melt mass flow rate of 20.0 g / 10 minutes and a melting point of 91 ° C. With respect to 100 parts by weight of the copolymer, tetrakis [methylene-3- (3,5-di-
[t-butyl-4-hydroxyphenyl) propionate] 0.5 part by weight of methane (Irganox 1010 manufactured by Ciba Specialty Chemical Co.) and 60 parts by weight of acetylene black are blended, and the mixture is kneaded at 130 ° C. for 10 minutes. 3 mm and a height of 3 mm were formed into cylindrical pellets. Next, the pellets containing organic peroxides 2,5
0.5 part by weight of -dimethyl-2,5-di (t-butylperoxin) hexyne was added, and the mixture was stirred slowly at 70 ° C for 5 hours to uniformly impregnate the organic peroxide into the inside of the pellet. A resin composition for an internal semiconductive layer was prepared.

(B) Preparation of Resin Composition for Chemically Crosslinkable Polyethylene Insulating Layer High-pressure low-density polyethylene (density 0.92 g / cm ³ ,
100 parts by weight of a melt mass flow rate (3.2 g / 10 min) were mixed with organic peroxide 2,5-dimethyl-2,5-di (t-
1.6 parts by weight of butylperoxy) hexine (Perhexin 25B manufactured by NOF Corporation), antioxidant 4,4'-thiobis (6-t-butyl-3-methylphenol) (Seanox BCS (Seenox, manufactured by Cipro Kasei) BC
S) A polyethylene resin composition containing 0.18 parts by weight was prepared as a resin composition for an insulating layer.

(C) Resin composition for external semiconductive layer A resin composition for external semiconductive layer comprising the following (a) to (g) was prepared. Component (a): vinyl acetate content 28% by weight, melt mass flow rate 20.0 g / 10 min, density 0.938 g /
100 parts by weight of an ethylene-vinyl acetate copolymer of cm ³ (b) component: melt mass flow rate 0.8 g / 10
Component, 70 parts by weight of a linear ethylene-butene-1 copolymer produced by a gas phase low pressure method having a density of 0.922 g / cm ³ (c) Component: melt mass flow rate 0.9 g / 10
20 parts by weight of polypropylene having a density of 0.900 g / cm ^{3 and} a component (d) having a viscosity of 300,000 cS at 23 ° C.
t, 5 parts by weight of a silicone gum stock having a methylvinylsilicone content of 1.0% (e) Component: Ketjen Black EC (manufactured by Mitsubishi Chemical Corporation)
30 parts by weight (f) Component: 0.3 parts by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexine (Perhexin 25B manufactured by NOF Corporation) (g) Component: tetrakis [methylene-3 -(3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (Irganox 1010 manufactured by Ciba Specialty Chemical Co.) 0.3 part by weight

(D) Preparation of Common Three-Layer Extrusion Apparatus Three extruders having screen packs of 150 mesh, 250 mesh, and 120 mesh respectively provided on a die plate are prepared, and these are connected to form an internal semiconductive material. The extruder had a common three-layer crosshead which was sequentially arranged as a layer extruder, an insulating layer extruder and an external semiconductive layer extruder.

(E) Production of chemically crosslinked polyethylene insulated power cable The resin composition for the inner semiconductive layer, the chemically crosslinkable polyethylene resin composition and the resin composition for the outer semiconductive layer prepared in the above (A) to (C) Were supplied to an internal semiconductive layer extruder, a chemically crosslinked polyethylene layer extruder and an external semiconductive layer extruder of a three-layer common extruder. Each of these components was heated and kneaded at 130 ° C. for the internal semiconductive layer extruder, 130 ° C. for the chemically crosslinked polyethylene layer extruder, and 160 ° C. for the external semiconductive layer extruder. On the hard copper stranded conductor, the thickness of the inner semiconductive layer is 1 mm, and the thickness of the chemically cross-linked polyethylene insulating layer is 4 m.
m, and extruded simultaneously so that the thickness of the outer semiconductive layer was 1 mm. Next, the crosslinking reaction was completed with a crosslinking tube heated to 230 ° C., and after cooling, a polyvinyl chloride compound was coated so as to have a thickness of 3 mm to form a jacket layer, thereby producing a chemically crosslinked polyethylene insulated power cable of the present invention.

The performance evaluation results of the chemically crosslinked polyethylene insulated power cable of the present invention are shown below. (1) Interface smoothness: The interface between the chemically cross-linked polyethylene insulating layer and the outer semiconductive layer was smooth and no protrusion exceeding 300 μm in diameter was observed. (2) Heating deformation rate of outer semiconductive layer: The rate of decrease in thickness is 1.
0%, indicating that the heat resistance was sufficient. (3) Peel test of outer semiconductive layer: Peel strength is 1.3
kg / 0.5 inch, and the peelability was sufficient. (4) Tensile strength of outer semiconductive layer: Tensile strength is 15.2
MPa, indicating that it was not torn when the external semiconductive layer was peeled off. (5) Elongation of outer semiconductive layer: elongation is 434%,
It was shown that when the cable was bent, it could follow the bending sufficiently. (6) Gel fraction of the chemically cross-linked polyethylene insulating layer: The gel fraction was 82%, which was sufficiently chemically cross-linked, and the heat resistance was sufficient. (7) Extrudability: melt mass flow rate is 55 g
/ 10 minutes, and the extrusion processability was sufficient. (8) Volume resistivity: Volume resistivity is 35Ω · c
m, which was an appropriate numerical value.

Example 2 (A) Preparation of Resin Composition for Internal Semiconductive Layer High-pressure ethylene-ethyl acrylate copolymer having an ethyl acrylate content of 23% by weight, a melt mass flow rate of 10 g / 10 minutes and a melting point of 98 ° C. The antioxidant tetrakis [methylene-3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] 0.5 part by weight of methane (Irganox 1010 manufactured by Ciba Specialty Chemical Co., Ltd.) and 80 parts by weight of acetylene black are blended and kneaded at 130 ° C. for 10 minutes. Pellets were used. Then, 0.5 parts by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne, which is an organic peroxide, was added to the pellet, and the mixture was heated at 70 ° C.
, The organic peroxide was uniformly impregnated into the inside of the pellet to prepare a resin composition for an internal semiconductive layer.

(B) Preparation of Resin Composition for Chemically Crosslinkable Polyethylene Insulating Layer High-pressure low-density polyethylene (density 0.920 g / c
m ³ , melt mass flow rate 3.2 g / 10 min) 10
1.6 parts by weight of organic peroxide 2,5-dimethyl-2,5-di (t-butylperoxy) hexine (Perhexin 25B manufactured by NOF Corporation) was added to 0 parts by weight, and the antioxidants 4,4 ′ were used.
-Thiobis (6-t-butyl-3-methylphenol)
(Seanox BCS manufactured by Cipro Kasei Co., Ltd.
BCS)) A polyethylene resin composition containing 0.18 parts by weight was prepared as a resin composition for an insulating layer.

(C) Preparation of a resin composition for an external semiconductive layer A resin composition for an external semiconductive layer comprising the following (a) to (g) was prepared. Component (a): ethyl acrylate content 32% by weight, melt mass flow rate 10.0 g / 10 min, density 0.9
41 g / cm ^{3 of} an ethylene-ethyl acrylate copolymer 100 parts by weight Component (b): melt mass flow rate 1.8 g / 10
Linear ethylene-hexene-1 prepared by a solution method using a single-site catalyst at a density of 0.935 g / cm ³ .
150 parts by weight of copolymer (c) component: melt mass flow rate 2.5 g / 10
Min, density 0.900 g / cm ³ , 40 parts by weight of a propylene-ethylene copolymer containing 5% by weight of ethylene (d) Component: viscosity at 23 ° C. of 150,000 cS
At t, 45 parts by weight of silicone gum stock having a methylvinylsilicone content of 0.7% (e) component: 130 parts by weight of furnace black (Ensako 250G manufactured by MMM Carbon Co.) (f) component: organic peroxide 2,5-dimethyl −2,5-
Di (t-butylperoxy) hexine (manufactured by NOF CORPORATION)
Perhexin 25B) 1.8 parts by weight (g) Component: tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (Irganox 1010 manufactured by Ciba Specialty Chemical Co.) 3 parts by weight

(D) Preparation of each layer extruder Three extruders each having a 150-mesh, 250-mesh, and 120-mesh screen pack installed on a die plate were prepared, and each extruder was used as an internal semiconductive layer extruder and an insulating layer extruder. And an external semiconductive layer extruder.

(E) Production of chemically crosslinked polyethylene insulated power cable The resin composition for the inner semiconductive layer, the chemically crosslinkable polyethylene resin composition and the resin composition for the outer semiconductive layer prepared in the above (A) to (C) Were supplied to an internal semiconductive layer extruder, a chemically crosslinked polyethylene layer extruder and an external semiconductive layer extruder of a three-layer common extruder. Each of these components was heated and kneaded at 130 ° C. for the internal semiconductive layer extruder, 130 ° C. for the chemically crosslinked polyethylene layer extruder, and 160 ° C. for the external semiconductive layer extruder, and then passed through a crosshead die of each extruder. On the hard copper stranded conductor, the thickness of the inner semiconductive layer is 1 mm, and the thickness of the chemically cross-linked polyethylene insulating layer is 4 m.
m, and the outer semiconductive layer was simultaneously coated so as to have a thickness of 1 mm. Next, the crosslinking reaction was completed with a crosslinking tube heated to 230 ° C., and after cooling, the polyvinyl chloride compound was coated to a thickness of 3 mm to form a jacket layer, thereby completing the chemically crosslinked polyethylene insulated power cable of the present invention. The performance evaluation of the chemically crosslinked polyethylene insulated power cable of the present invention was performed by the same test method as the test method shown in Example 1. The results are shown below.

(1) Interface smoothness: The interface between the chemically cross-linked polyethylene insulating layer and the outer semiconductive layer is smooth and has a diameter of 30
No protrusion of 0 μm or more was observed. (2) Heat resistance of the outer semiconductive layer: The reduction rate was 1.4%, and the heat resistance was sufficient. (3) Peeling test of outer semiconductive layer: peeling strength is 1.4k
g / 0.5 inch, and the releasability was sufficient. (4) Tensile strength of the outer semi-electric layer: 12.8 MPa,
When the outer semiconductive layer was peeled off, it was shown not torn. (5) Elongation of the outer semiconductive layer: 381%, indicating that when the cable is bent, it can sufficiently follow the bending. (6) Gel fraction of chemically crosslinked polyethylene insulating layer: 82%
And the composition was sufficiently chemically crosslinked and had sufficient heat resistance. (7) Extrudability: melt mass flow rate (temperature 19)
(0 ° C., load: 21.6 kg) was 45 g / 10 minutes, and the extrusion processability was sufficient. (8) Volume resistivity: 35 Ω · cm, which was an appropriate value.

Example 3 The same experiment as in Example 1 was performed except that the resin composition comprising the following (a) to (g) was used instead of the resin composition of the outer semiconductive layer of Example 1. Was. Component (a): butyl acrylate content 17% by weight, melt mass flow rate 5.0 g / 10 minutes, density 0.93
7 g / cm ³ 100 parts by weight of ethylene-butyl acrylate copolymer (b) Component: melt mass flow rate 20.0 g / 10
100 parts by weight of a linear ethylene-hexene-1 copolymer prepared by a gas phase method and a low pressure method with a density of 0.900 g / cm ³ (c) Component: melt mass flow rate 1.2 g / 10
7 parts by weight of polypropylene having a density of 0.910 g / cm ^{3 and} a component (d) having a viscosity of 3,000 cSt at 23 ° C.
And 30 parts by weight of dimethylpolysiloxane oil containing 0.8% of methyl vinyl silicone (e) Component: Ketjen Black EC (manufactured by Mitsubishi Chemical Corporation) 3
0 parts by weight (f) Component: 1.8 parts by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexine (Perhexin 25B manufactured by NOF Corporation) (g) Component: tetrakis [methylene-3] -(3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (Irganox 1010 manufactured by Ciba Specialty Chemical Co.) 0.3 part by weight

The results are shown below. (1) Interface smoothness: At the interface between the chemically cross-linked polyethylene insulating layer and the external semiconductive layer, the interface was smooth and no protrusion having a diameter of 300 µm or more was observed. (2) Heat resistance of the outer semiconductive layer: the rate of decrease in thickness is 1.1%
And the heat resistance was sufficient. (3) Peeling test of outer semiconductive layer: Peeling strength is 1.8k
g / 0.5 inch, and the releasability was sufficient. (4) The tensile strength of the outer semi-electric layer is 10.6 MPa,
When the outer semiconductive layer was peeled off, it was shown not torn. (5) Elongation of the outer semiconductive layer: 421%, indicating that the cable can sufficiently follow the bending when bent. (6) Gel fraction of chemically crosslinked polyethylene insulating layer: 82%
And the composition was sufficiently chemically crosslinked and had sufficient heat resistance. (7) Extrudability: melt mass flow rate (temperature 19)
(0 ° C., load 21.6 kg) was 62 g / 10 minutes, and the extrusion processability was sufficient. (8) Volume resistivity: 53 Ω · cm, which was an appropriate value.

Comparative Example 1 The same experiment as in Example 1 was carried out except that the ethylene-vinyl acetate copolymer (EVA) of (a) was replaced with EVA having a vinyl acetate content of 8.0%. Where
The flexibility and elongation of the outer semiconductive layer deteriorated.

Comparative Example 2 The same experiment as in Example 1 was conducted, except that the ethylene-vinyl acetate copolymer (EVA) of (a) was replaced with EVA having a vinyl acetate content of 55%. However,
The tensile strength of the outer semiconductive layer was weakened, and the operation of peeling the outer semiconductive layer was not successful.

Comparative Example 3 In Example 1, the ethylene-vinyl acetate copolymer (EVA) of (a) was prepared by adding a melt mass flow rate of 0.8 g /
The same experiment as in Example 1 was performed except that EVA was used for 10 minutes. As a result, the extrudability, flexibility, elongation, and the like of the outer semiconductive layer were insufficient.

Comparative Example 4 In Example 1, the ethylene-vinyl acetate copolymer (EVA) of (a) was used at a melt mass flow rate of 120 g /
When an experiment similar to that of Example 1 was performed except that EVA was used for 10 minutes, the tensile strength and heat resistance of the external semiconductive layer were insufficient.

Comparative Example 5 The same experiment as in Example 1 was carried out except that the ethylene-butene-1 copolymer (b) was replaced with one having a melt mass flow rate of 0.08 g / 10 min. As a result, the workability of the external semiconductive layer deteriorated.

Comparative Example 6 An experiment was conducted in the same manner as in Example 1 except that the ethylene-butene-1 copolymer (b) was replaced with one having a melt mass flow rate of 35.0 g / 10 minutes. As a result, the tensile strength of the outer semiconductive layer became weak.

Comparative Example 7 An experiment was carried out in the same manner as in Example 1 except that the ethylene-butene-1 copolymer (b) was replaced with one having a density of 0.85 g / cm ^3. In addition, the heating deformation rate of the outer semiconductive layer at 120 ° C. or more deteriorated.

Comparative Example 8 An experiment was conducted in the same manner as in Example 1 except that the ethylene-butene-1 copolymer (b) was replaced with one having a density of 0.948 g / cm ^3. In addition, the flexibility of the outer semiconductive layer deteriorated.

Comparative Example 9 An experiment was conducted in the same manner as in Example 1 except that the amount of the ethylene-butene-1 copolymer (b) was changed to 50 parts by weight. At 120 ° C. or higher.

Comparative Example 10 An experiment was conducted in the same manner as in Example 1 except that the amount of the ethylene-butene-1 copolymer (b) was changed to 220 parts by weight. The flexibility and elongation of the layer and the filling properties of carbon black deteriorated.

Comparative Example 11 An experiment was conducted in the same manner as in Example 1 except that the polypropylene in (c) was replaced with one having a melt mass flow rate of 0.3 g / 10 min. Workability deteriorated.

Comparative Example 12 An experiment was conducted in the same manner as in Example 1 except that the polypropylene in (c) was replaced with a melt mass flow rate of 33.0 g / 10 min. Became weaker in tensile strength.

Comparative Example 13 The polypropylene of Example 1 was prepared by using the polypropylene of (c) with a melt mass flow rate of 2.0 g / 10 minutes and a density of 0.89.
When an experiment similar to that of Example 1 was performed except that the thickness of the external semiconductive layer was changed to 5 g / cm ³ , a heating deformation rate of the external semiconductive layer at 120 ° C. or more was deteriorated.

Comparative Example 14 In Example 1, the polypropylene (c) was prepared by subjecting the polypropylene to the melt mass flow rate of 5.4 g / 10 min and the density of 0.92.
When an experiment similar to that of Example 1 was performed except that the weight was changed to 5 g / cm ³ , the flexibility of the external semiconductive layer was deteriorated.

Comparative Example 15 In Example 1, the amount of the polypropylene (c) was changed to 3
The same experiment as in Example 1 was performed except that the weight was changed to parts by weight. As a result, the heat deformation rate and the peeling property of the external semiconductive layer were insufficient.

Comparative Example 16 The amount of the polypropylene (c) used in Example 1 was changed to 5
When an experiment similar to that of Example 1 was performed except that the amount was changed to 5 parts by weight, the flexibility and cold resistance of the outer semiconductive layer were deteriorated.

Comparative Example 17 An experiment was conducted in the same manner as in Example 1 except that the amount of the silicone gum stock in (d) was changed to 0.3 parts by weight. The smooth peelability was insufficient.

Comparative Example 18 An experiment was conducted in the same manner as in Example 1 except that the amount of the silicone gum stock in (d) was changed to 55 parts by weight. The properties deteriorated and the tensile strength was insufficient.

Comparative Example 19 An experiment was conducted in the same manner as in Example 1 except that the amount of Ketjen black in (e) was changed to 8.0 parts by weight. Resistance value is 200Ω
Cm.

Comparative Example 20 An experiment was conducted in the same manner as in Example 1 except that the amount of Ketjen black in (e) was changed to 420 parts by weight. The properties, flexibility and elongation were insufficient.

Comparative Example 21 In Example 1, the amount of the organic peroxide (f) was changed to 10.0
The same experiment as in Example 1 was performed except that the weight part was changed. As a result, a large number of protrusions were generated on the surface of the semiconductive layer, and a smooth surface was not obtained.

[0071]

According to the present invention, there is provided a peelable semiconductive resin composition used as an outer semiconductive layer of a chemically crosslinked polyethylene insulated power cable, comprising a specific ethylene-vinyl acetate copolymer and ethylene-ethyl acrylate copolymer. One or more selected from a copolymer and an ethylene-butyl acrylate copolymer, a linear ethylene-α-olefin copolymer, polypropylene, an organopolysiloxane, carbon black and, if necessary, an organic peroxide. Since it is used in specific amounts, appropriate semi-conductivity, peelability, tensile strength, adhesion, workability, surface smoothness, cold resistance,
It exhibits excellent effects on heat resistance and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 83/07 C08L 83/07 H01B 9/02 H01B 9/02 B 13/14 13/14 A (72) Inventor Koji Ishihara 7-16-12 Ebara, Shinagawa-ku, Tokyo F-term (reference) 4J002 BB05X BB06W BB07W BB123 CP134 DA036 EK017 EK037 EK047 EK057 EK087 GQ01 GQ02 5G301 DA18 DA42 DA43 DA45 DA48 DD04 5G325 GA01 GC06

Claims (4)

[Claims] 1. Use as an outer semiconductive layer of a chemically crosslinked polyethylene insulated power cable in which an inner semiconductive layer, a chemically crosslinked polyethylene insulating layer, an outer semiconductive layer and a jacket layer are formed on a conductor from inside to outside. A peelable semiconductive resin composition comprising the following components (a), (b), (c), (d), (e) and (f). (A) (I) an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 50% by weight and a melt mass flow rate of 1.0 to 100.0 g / 10 minutes, and (II) an ethyl acrylate content of 10 to 50% by weight. Ethylene-ethyl acrylate copolymer having a melt mass flow rate of 1.0 to 100.0 g / 10 min, and (III) a butyl acrylate content of 10 to 50% by weight, and a melt mass flow rate of 1.0 to 100.0 g / 10 min. At least one selected from ethylene-butyl acrylate copolymers
00 parts by weight (b) Melt mass flow rate 0.1 to 30.0 g / 1
0 minute, 55 to 200 parts by weight of a linear ethylene-α-olefin copolymer having a density of 0.870 to 0.944 g / cm ³ (c) Melt mass flow rate 0.5 to 30.0 g / 1
0 min, 5 to 50 parts by weight of polypropylene having a density of 0.900 to 0.920 g / cm ³ (d) The following formula (A) (Wherein, R ¹ is an aliphatic unsaturated hydrocarbon group, R ² is an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group,
0 ≦ x <1, 0.5 <y <3, 1 <x + y <3, 0 <a
≦ 1, 0.5 ≦ b ≦ 3. 0.5 to 50 parts by weight of an organopolysiloxane represented by the formula (e): 10 to 400 parts by weight of carbon black (f) 0 to 2.0 parts by weight of an organic peroxide 2. A resin composition for an internal semiconductive layer on a conductor, a resin composition for a chemically cross-linkable polyethylene insulating layer, and
In the step of sequentially coating the peelable semiconductive resin composition according to the above, the step of coating the resin composition for the internal semiconductive layer and the resin composition for the chemically crosslinkable polyethylene insulating layer is performed by a two-layer simultaneous extrusion device. A method for producing a chemically cross-linked polyethylene insulated power cable, comprising the step of coating the above-mentioned releasable semiconductive resin composition. 3. A resin composition for an internal semiconductive layer, a resin composition for a chemically crosslinkable polyethylene insulating layer on a conductor, and
3. The method for producing a chemically crosslinked polyethylene insulated power cable, wherein the step of sequentially coating the releasable semiconductive resin composition according to <1> is performed by a three-layer coextrusion apparatus. 4. A chemically cross-linked polyethylene insulated power cable manufactured by the method of claim 2.