JPH1192600A - Easily-peelable semiconductive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easily-peelable semiconductive resin composition having a good mechanical strength and heat resistance and an appropriate peel strength which is easily cross-linked. SOLUTION: An easily-peelable semiconductive resin composition comprises (A) from 10 to 80 pts.wt. modified ethylene copolymer obtained by exposing an ethylene copolymer (a1) and a vinyl monomer (a2) to a graft polymerization condition, (B) from 90 to 20 pts.wt. ethylene and a copolymer of an olefin- unsaturated silane compound and an ethylene unsaturated compound, which is represented by the formula: RSiR'n Y3-n (wherein R is an ethylene unsaturated hydrocarbyl or hydrocarbyloxy group; R' is an aliphatic saturated hydrocarbyl group; Y is a hydrolyzable organic group; n is 0, 1 or 2) and (C) from 10 to 110 pts.wt. carbon black.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vinyl monomer graft-modified ethylene copolymer, an ethylene / unsaturated silane compound / ethylenically unsaturated compound copolymer, and a carbon black as a main component. The present invention relates to a silane crosslinkable easily peelable semiconductive resin composition having excellent mechanical strength, heat resistance and moderate peel strength.

[0002]

2. Description of the Related Art Conventionally, in a power cable, a cable of a type in which a semiconductive layer is provided on the inner and outer layers of an insulating layer for the purpose of relaxing an electric field has been used. This semiconductive layer has the meaning of preventing corona discharge. Therefore, it is necessary to adhere or adhere to the insulating layer without any gap. However, if the outer semiconductive layer and the insulating layer are excessively adhered, it is extremely difficult to peel the outer semiconductive layer from the insulating layer, for example, when connecting cables, and as a result, it takes a long time to peel off. Required, and the insulating layer is easily damaged, which requires a great deal of time and effort for the terminal treatment,
Alternatively, skill is required. Conventionally, a semiconductive layer based on an ethylene / vinyl ester copolymer, which is considered to be the best as this type of semiconductive layer, has a property of extremely strongly adhering to the olefin polymer constituting the insulating layer. Therefore, the strippability from the insulating layer is almost zero, which makes the cable terminal treatment extremely difficult.

According to the present invention, the insulating layer and the external semiconductive layer are in close contact with an appropriate strength, and the external semiconductive layer can be peeled off very easily if necessary. It is an object of the present invention to provide a semiconductive resin composition having good mechanical strength such that a release layer is not easily cut.

[0004] The relationship with the prior art will be described in more detail. As the semiconductive layer material, (1) ethylene / vinyl acetate such as ethylene / vinyl acetate copolymer or ethylene / ethyl acrylate copolymer having a high vinyl acetate content; An ester copolymer or an ethylene / acrylate copolymer blended with carbon black. (2) Chlorinated polyethylene, chlorosulfonated polyethylene, EVA
Halogen-containing resins such as vinyl chloride graft copolymers alone or blended with an olefin polymer,
There have been proposed, for example, those in which carbon black is added, (3) polystyrene, styrene copolymer, butadiene / acrylonitrile copolymer, polyester and the like are blended with olefin polymer, and carbon black is added thereto.

[0005] However, these semiconductive resins have the following problems. As described above, the blend described in the above (1) has poor releasability from the insulating layer, and cannot satisfy the object of the present invention. The blend according to the above (2) has been proposed for the purpose of improving the releasability from the insulating layer, and although the effect for the purpose is recognized, the halogen-containing resin is not heat-resistant at a high temperature. Decomposition produces corrosive gases, which can lead to corrosion of equipment,
There is a problem that the copper shielding tape of the cable is corroded and the performance of the cable is deteriorated. Further, the blend described in the above (3) is intended to improve the releasability from the insulating layer, similarly to the blend described in the above (2). Since the solubility is poor and the amount of blending must be increased in order to improve the releasability, the outer semiconductive layer becomes considerably brittle as a result, causing problems such as the release layer being cut off during the release process. . Therefore, when practically used as a covering material for an electric power cable, an organic peroxide is added to the above materials (1), (2), and (3) in order to impart heat resistance to the material, and the temperature is lowered. , And then cross-linked by a special cross-linking device to perform the production in a two-step process.

On the other hand, a silane crosslinking method has been proposed as a method for remarkably improving the productivity of a crosslinking method using an organic peroxide (hereinafter referred to as "peroxide crosslinking"). The silane crosslinking method is disclosed in JP-B-48-1711 and JP-B-Sho-6-17.
After molding a silane-containing polyolefin known in JP-A-2-23777 and the like in the presence of a silanol condensation catalyst,
Since crosslinking is carried out in a moisture atmosphere, there is an advantage that the equipment for crosslinking is simpler and the productivity is remarkably higher than the conventional peroxide crosslinking method. For this reason, silane-crosslinked polyethylene has been widely used as an insulating layer of low-voltage cables, and more recently, Japanese Patent Publication No. 7-3194.
As described in Japanese Patent Application Laid-Open No. 7-293, and Japanese Patent Application Laid-Open No. 4-293945, application to a high-voltage cable is being studied. However, from the viewpoint of appropriate releasability from the insulating layer, a technique that is not always satisfactory in this silane crosslinking method has not been proposed.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an easily peelable semiconductive resin composition which solves all the disadvantages of the above-mentioned method and satisfies the following items. The purpose is to obtain. 1. Close contact with the insulating layer with appropriate strength. 2. It can be easily separated from the insulating layer if necessary. 3. Have excellent mechanical strength. 4. Good dispersibility of carbon black. 5. Have excellent extrudability. 6. Excellent thermal stability and no generation of corrosive decomposition gas. 7. Easy cross-linking process and high productivity.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a specific modified ethylene copolymer and an ethylene / unsaturated silane compound.
It has been found that the above object can be achieved by using a copolymer of an olefinically unsaturated compound in combination. That is, the easily peelable semiconductive resin composition of the present invention is characterized by containing the following components (A), (B) and (C). Here, the compounding amount of the component (C) is based on a total of 100 parts by weight of the component (A) and the component (B). Component (A): Modified ethylene copolymer obtained by subjecting ethylene copolymer (a1) and vinyl monomer (a2) to graft polymerization conditions 10 to 80 parts by weight Component (B): ethylene general formula RSiR' _n Y _3-n olefin emissions unsaturated silane compound represented by a copolymer 90 to 20 parts by weight of an ethylenically unsaturated compound (wherein, R is a hydrocarbyl group having an ethylenically unsaturated or Represents a hydrocarbyloxy group, R ′ represents an aliphatic saturated hydrocarbyl group, Y represents a hydrolyzable organic group, and n is 0, 1, or 2.) Component (C): 10 to 110 weight of carbon black Department

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

[I] Easy-peeling semiconductive resin composition (1) Component (A) Component (A): Modified ethylene copolymer The modified ethylene copolymer used as the component (A) in the present invention is: And a modified ethylene copolymer (A) obtained by subjecting an ethylene copolymer (a1) and a vinyl monomer (a2) to graft polymerization conditions.

(A) Ethylene copolymer (a1) Here, ethylene copolymer (a1) is composed of ethylene as a main component and α-olefin such as propylene, butene and octene as its comonomer; Or a copolymer with a vinyl ester represented by vinyl acetate, acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, or an unsaturated carboxylic acid or a derivative thereof such as an ester, each used alone or two or more kinds They can be used together. These include those polymerized with a single-site catalyst. Among them, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / acrylic ester copolymer, ethylene / methacrylic ester copolymer and the like are preferable. The content of ethylene comonomer such as α-olefin, vinyl ester, unsaturated carboxylic acid or its ester derivative in the ethylene copolymer (a1) is generally 20 to 50% by weight, preferably 25 to 50% by weight. It is 45% by weight, particularly preferably 25 to 40% by weight. If the content of the comonomer is too low, the releasability tends to be insufficient. On the other hand, if it is higher than the above range, the heat resistance tends to decrease. The ethylene copolymer (a1) has a melt flow rate (MF) from the viewpoint of suitability for graft reaction, kneading with carbon black, and moldability.
R: 190 ° C, 2.16 kg load) 0.1 to 300 g
/ 10 min, especially 0.5 to 200 g / 10 min, especially 1 to 1
Those having a flow rate of 100 g / 10 minutes are preferred.

(B) Vinyl monomer (a2) Specific examples of the vinyl monomer (a2) subjected to the graft polymerization conditions with the ethylene copolymer (a1) include styrene and 2- Unsaturated aromatic monomers such as methylstyrene, 3-methylstyrene, 4-methylstyrene, dimethylstyrene, and chlorostyrene; vinyl esters such as vinyl acetate and vinyl propionate; methyl acrylate, ethyl acrylate, isopropyl acrylate;
Acrylic esters such as n-butyl acrylate, s-butyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, hexyl acrylate, octyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, s-butyl methacrylate, decyl methacrylate, 2 -Methacrylic esters such as ethylhexyl methacrylate and glycidyl methacrylate; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride, dimethyl maleate and di (2-ethylhexyl) maleate; unsaturated carboxylic acids such as acrylonitrile and methacrylonitrile; Saturated nitriles; examples thereof include unsaturated mono- or di-halides such as vinyl chloride and vinylidene chloride. Among them, aromatic vinyl monomers such as styrene, or methyl methacrylate,
In particular, the modified ethylene copolymer (A) obtained from styrene is preferred in view of the properties and easy modification. The amount of the vinyl monomer (a2) used is such that the content in the obtained modified ethylene copolymer (A) is such that the vinyl monomer graft-bonded to the ethylene copolymer (a1) is used. (A
The total amount of 2) and the homopolymer of the vinyl monomer (a2) is set so as to be 10 to 60% by weight, preferably 20 to 50% by weight. Approximately matches. If the content is too low, the effect of improving the compatibility tends to be small. On the other hand, if the content is too high, the effect of improving the compatibility tends to be low because the phase transition occurs.

(C) Graft polymerization conditions (production of modified ethylene copolymer (A)) The above ethylene copolymer (a1) and vinyl monomer (a)
As the radical generator used in producing the modified ethylene copolymer (A) by subjecting 2) to the graft polymerization conditions, a general-purpose radical generator can be used, but a preferable graft generator described later is used. From the viewpoint of the reaction method, those having a decomposition temperature of 50 ° C. or higher and being oil-soluble are preferred. When a material having a low decomposition temperature is used, the polymerization of the vinyl monomer (a2) may proceed abnormally, and a homogeneous modified ethylene copolymer (A) may not be obtained. However, conversely, those having a high decomposition temperature and those having a low decomposition temperature can be appropriately combined to perform the decomposition stepwise or continuously, and the graft reaction can be carried out efficiently.

Examples of such radical generators include 2,4-dichlorobenzoyl peroxide, t-butylperoxypivalate, and o-methylbenzoylperoxide.
Oxide, bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, t-butyl peroxy-2-ethylhexanoate, cyclohexanone peroxide, 2,5-dimethyl-oxide 2,5-dibenzoylperoxyhexane, t-butylperoxybenzoate, di-
t-butyl-diperoxyphthalate, methyl ethyl ketone peroxide, dicumyl peroxide, di-t
Organic peroxides such as -butyl peroxide; azo compounds such as azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile). The amount of the radical generator used is generally within the range of about 0.01 to 10% by weight based on the amount of the vinyl monomer (a2) used, and is appropriately adjusted depending on the type of the radical generator and the reaction conditions. If the amount used is less than this amount, the reaction does not proceed smoothly, while if it exceeds this amount, a gel tends to be easily formed in the modified ethylene copolymer (A).

In order to obtain a modified ethylene copolymer (A) by subjecting each of these raw materials to a graft polymerization reaction, the copolymer is produced by an aqueous suspension grafting technique as disclosed in JP-B-63-20266. Is a particularly preferable method in that the gel content can be easily controlled. That is, ethylene-based copolymer (a1) particles (having a diameter of generally 1 to 7 mm, preferably 2 to 5 mm) 1
00 parts by weight, 25 to 200 parts by weight of the vinyl monomer (a2), and a decomposition temperature of 50 to 1 to obtain a half-life of 10 hours.
A radical generator at 30 ° C. was added to a vinyl monomer (a2) 1
0.01 to 5 parts by weight to 00 parts by weight of a suspending agent used for aqueous suspension polymerization, for example, polyvinyl alcohol,
In the presence of polyvinylpyrrolidone, methylcellulose, or other hardly soluble inorganic substances, for example, calcium phosphate, magnesium oxide, etc., in an aqueous medium at any concentration that facilitates stirring of the system (generally 100 parts by weight of water On the other hand, an ethylene copolymer (a1) particle and a vinyl monomer (a2) are added in an amount of 5 to 100 parts by weight, and the mixture is stirred and dispersed. Next, a polymerization treatment is performed. Prior to this, the aqueous suspension is heated within a range in which decomposition of the radical generator to be used does not substantially occur to convert the vinyl monomer (a2) into an ethylene-based copolymer ( a1) Impregnating into particles.

In the impregnation treatment, the heating temperature is preferably higher from the viewpoint of accelerating the impregnation. However, since the vinyl monomer (a2) before the impregnation is polymerized by premature decomposition of the radical generator, this is prevented. The lower the heating temperature is, the better
Preferably it is from room temperature to 50 ° C. or lower. Under such temperature conditions, 80% by weight or more, preferably 90% by weight or more of the vinyl monomer (a2) is impregnated or adhered to the ethylene-based copolymer (a1) particles, Less than 20% by weight of monomer droplets, preferably 10% by weight
The aqueous suspension is left to a volume of less than 1 to 5 hours, preferably under stirring. Unimpregnated vinyl monomer (a
When 2) is 20% by weight or more, the independent vinyl monomer (a
The polymer particles of 2) may precipitate, and the vinyl monomer (a2) in the ethylene-based copolymer (a1) particles
Tends to be non-uniform. Since the free vinyl monomer (a2) is impregnated in the particles of the ethylene copolymer (a1) in the next polymerization step or adheres to the surface of the particles and polymerizes, the vinyl monomer is contained in the product. It is practically not recognized that the polymer particles of the body (a2) exist independently of the ethylene-based copolymer (a1) particles.

The aqueous suspension thus prepared is further heated to a high temperature to complete the polymerization of the vinyl monomer (a2), whereby the modified ethylene copolymer (A) is obtained. At this time, the heating temperature should be a temperature at which sufficient decomposition of the radical generator used occurs. However, it is preferred not to exceed 130 ° C. If it exceeds 130 ° C., a gel-like substance tends to be formed in the modified ethylene copolymer (A), and a temperature of 50 to 130 ° C. is generally suitable.

The modified ethylene-based copolymer (A) thus obtained comprises an ethylene-based copolymer (a1) and a vinyl monomer (a2) and a graft ethylene-based copolymer and a vinyl monomer (A). The three components of the polymer a2) are mixed, and the compatibility of the polymer of the ethylene-based copolymer (a1) and the polymer of the vinyl monomer (a2) is improved by the presence of the graft component. The polymer of a2) is an ethylene copolymer (a1)
It is homogeneously and finely dispersed in the matrix. Therefore, even if the vinyl monomer (a2) unit is increased, its homogeneity is not impaired, and the appearance and physical properties of the molded product are excellent. In a simple blend system of an ethylene copolymer (a1) and a polymer of a vinyl monomer (a2), the compatibility is poor due to poor compatibility between the two, and the appearance is degraded due to the occurrence of delamination during the molding process. And, due to the remarkable decrease in material properties, it is not practical. The amount of the modified ethylene copolymer (A) is
10 to 80 parts by weight, preferably 15 to 70 parts by weight, particularly preferably 2 to 100 parts by weight based on 100 parts by weight of the total of the component (A) and the component (B) which are generally polymer components.
0 to 60 parts by weight. If the amount is too small, the releasability will be insufficient. On the other hand, if it is more than the above range, the degree of crosslinking is insufficient, and the heat resistance becomes insufficient.

(B) Component (B): Ethylene / unsaturated silane compound / ethylenically unsaturated compound copolymer Ethylene / unsaturated silane compound / ethylenically unsaturated compound copolymer used as component (B) in the present invention. The union is a terpolymer obtained by subjecting ethylene, the unsaturated silane compound (b1) and the ethylenically unsaturated compound (b2) to polymerization conditions.

[0019] (a) an unsaturated silane compound (b1) an unsaturated silane compound is copolymerized with ethylene in the present invention (b1) as the preferred example, the general formula RSiR _'n Y _3-n Things can be shown.

R in the above formula is an ethylenically unsaturated hydrocarbyl group or hydrocarbyloxy group, which has radical reactivity. Examples of such groups include vinyl, allyl, butenyl, cyclohexenyl, cyclopentadiel, and γ- (meth) acryloxypropyl. R ′ is an aliphatic saturated hydrocarbyl group, such as methyl, ethyl, propyl, and decyl. Y represents a hydrolyzable organic group, and n is 0, 1 or 2. Specific examples of Y include methoxy, ethoxy, formyloxy, acetoxy, propionyloxy, alkyl and arylamino. Particularly preferred is the general formula

[0021]

Embedded image

Wherein R ¹ is H or CH ₃ , R ² is a linear or branched alkyl group having 4 or less carbon atoms, and R ³ is R ² or a linear or branched alkyl group having 4 or less carbon atoms or phenyl group. ), Specifically, vinyltrimethoxysilane, vinyltriethoxysilane,
Examples thereof include vinyl tripropoxy silane, vinyl triacetoxy silane, vinyl methyl diethoxy silane, and vinyl ethyl dimethoxy silane. Further, as another preferred unsaturated silane compound (b1), a compound represented by the general formula:

[0023]

Embedded image

Wherein R ⁴ is H or CH ₃ , R ⁵ is a linear alkyl group having 4 or less carbon atoms, R ⁶ is R ⁵ or 4 carbon atoms.
The following linear alkyl groups or phenyl groups, wherein n is 1
6 to an integer. ), And specific examples thereof include γ-methacryloxypropylmethoxysilane.

In general, a water-crosslinked copolymer having a higher content of the unsaturated silane compound (b1) is more excellent in mechanical strength and heat resistance. However, when the content is excessively high, tensile elongation and processability are reduced. Therefore, the content of the unsaturated silane compound unit is usually about 0.1 to 10% by weight, preferably about 0.3 to 5% by weight, particularly preferably 0.5 to 3% by weight. In order to improve the extrusion appearance, the specific amount of the saturated or unsaturated silane compound having a silane group which can be hydrolyzed at the time of extrusion (0.01 to 5 parts by weight, preferably 100 parts by weight of component (B)) is preferable. Is 0.05 to 3 parts by weight, particularly preferably 0.1 to 2 parts by weight). Specific examples of such a silane compound include vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, hexyltrimethoxysilane, and the like.

(B) Ethylenically unsaturated compound (b2) The ethylenically unsaturated compound (b) used in the present invention
As 2), those having a nitrogen atom and an oxygen atom are used. As such compounds, suitable and ordinary compounds, for example, vinyl esters such as vinyl acetate, vinyl butyrate and vinyl piperate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate (Meth) acrylic acid esters such as, unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, fumaric acid,
(Meth) acrylonitrile, (meth) acrylic acid derivatives such as (meth) acrylamide, and vinyl ethers such as vinyl methyl ether and vinyl phenyl ether. These can be used alone or in combination of two or more. Those preferably used in the present invention include vinyl esters of monocarboxylic acids having about 1 to 4 carbon atoms, for example, vinyl acetate and (meth) acrylic esters of alcohols having about 1 to 4 carbon atoms, for example, (meth) Methyl acrylate, ethyl (meth) acrylate and the like. The “(meth) acrylic acid” means both acrylic acid and methacrylic acid. The content of the ethylenically unsaturated compound (b2) unit in the copolymer (B) (in the case of a combination of two or more kinds) can be in a wide range, but is generally from 1 to 45% by weight, preferably from 1 to 45% by weight. The content is 5 to 45% by weight, particularly preferably 10 to 40% by weight.

[Production of Copolymer] The copolymerization of ethylene, the unsaturated silane compound (b1) and the ethylenically unsaturated compound (b2) may be carried out under any conditions under which the copolymerization of the three occurs. Specifically, for example, a pressure of 500 to 4,000
kg / cm ² , preferably 1,000 to 4,000 kg
/ Cm ² , temperature 100-400 ° C., preferably 150-400 ° C.
At 300 ° C., in the presence of a radical polymerization initiator and, if necessary, a chain transfer agent, in a barrel or tube reactor, preferably a barrel reactor, each monomer is simultaneously or stepwise. The ethylene-unsaturated silane compound (b1) / ethylenically unsaturated compound (b2) copolymer (B) can be produced by contacting the polymer.

In the present invention, any radical generator and chain transfer agent known to be used for homopolymerization or copolymerization of ethylene can be used. Examples of the radical generator include lauroyl peroxide, dipropionyl peroxide, benzoyl peroxide, di-t-butyl peroxide, t-butyl peroxy-2-ethylhexanoate, t-butyl hydroxy peroxide, and t-butyl hydroxy peroxide. Organic peroxides such as butylperoxyisobutyrate, molecular oxygen, and azo compounds such as azoisobutyronitrile and methylazoisobutyrate can be exemplified. As the chain transfer agent, methane,
Paraffinic hydrocarbons such as ethane, propane, butane and pentane, propylene, butene-1, hexene-1
And aldehydes such as formaldehyde, acetaldehyde and n-butyraldehyde, ketones such as acetone, methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons and chlorinated hydrocarbons.

The amount of the ethylene / unsaturated silane compound / ethylenically unsaturated compound copolymer (B) is 90 to 20 parts by weight based on 100 parts by weight of the total of the component (A) and the component (B). Parts by weight, preferably 85 to 30 parts by weight,
Particularly preferred is 80 to 40 parts by weight. If the amount is too large, the releasability will be insufficient. On the other hand, if the amount is too small, the degree of crosslinking becomes insufficient, and the heat resistance becomes insufficient. In this case, from the viewpoint of compatibility of the two components, the olefinically unsaturated compound (b2) is the same as the ethylene comonomer of the ethylene copolymer (a2) in the modified ethylene copolymer (A). It is preferable to use one. If the ethylene comonomer content of the ethylene copolymer (a1) in the component (A) and the content of the ethylenically unsaturated compound (b2) in the component (B) are within the above ranges, (a1) , (B
There is no problem even if those having different contents of 2) are used.

(C) Component (C): Carbon Black The carbon black used as the component (C) in the present invention may be any carbon as long as the resin composition of the present invention satisfies the intended conductivity. Black can also be used. As such carbon black,
For example, commercially available furnace black, acetylene black, Ketjen black, channel black, thermal black and the like can be mentioned. The compounding amount is generally 10 to 110 parts by weight, preferably 20 to 90 parts by weight, particularly preferably 40 to 90 parts by weight based on 100 parts by weight of the total of the components (A) and (B), which are generally polymer components. 80
Parts by weight. If the amount is too small, good semiconductivity cannot be obtained, while if it is too large, extrudability and mechanical properties are impaired, which is not preferable.

(D) Component (D): Other optional components In the present invention, if necessary, other components such as an antioxidant, a weathering agent, an ultraviolet absorber, and a corrosion inhibitor are used as long as the effects of the present invention are not significantly impaired. Additives such as agents, lubricants, pressure-sensitive adhesives, dispersants and the like may be added as optional components.

(2) Preparation of easily peelable semiconductive resin composition (A) Melt kneading The easily peelable semiconductive resin composition of the present invention comprises component (A), component (B) and component (C). ) Can be produced by melt-kneading the components. In general, melt kneading is carried out using a conventional kneader such as a single-screw kneader, a twin-screw kneader, a Banbury mixer, or a roll. However, a melt-kneader using a twin-screw kneader or a Banbury mixer is preferable in terms of efficiency.

(B) Silanol Condensation Catalyst In the production of these, a silanol condensation catalyst can be added if necessary. Examples of the silanol condensation catalyst include metal carboxylate salts such as tin, zinc, iron, lead, and cobalt; organometallic compounds such as titanates and chelates; organic bases; inorganic acids; and organic acids.
Specifically, dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, stannous acetate, stannous caprylate, lead naphthenate, zinc caprylate, cobalt naphthenate, tetrabutyl titanate, tetrabutyl titanate, tetratitanate Examples thereof include inorganic acids such as nonier ester, ethylamine, dibutylamine, hexylamine, pyridine, sulfuric acid, and hydrochloric acid, and organic acids such as toluenesulfonic acid, acetic acid, stearic acid, and maleic acid. The amount of the silanol condensation catalyst to be used is generally 0.001 to 10 parts by weight, preferably 0.01 to 5 parts by weight, particularly preferably 0.01 to 1 part by weight, based on 100 parts by weight of the resin component. . As an addition method, it is used by mixing before molding or by applying or impregnating a molded article as a solution or dispersion. When used as a laminate with a polyolefin-based resin, it may be added to each layer of the easily peelable semiconductive resin composition or the polyolefin-based resin, or to both layers.

(C) Bridge In this way, the molded article in which the silanol condensation catalyst is present can be cross-linked by exposing it to water for the purpose of imparting heat resistance. Exposure to water is carried out by subjecting the molded body to room temperature to about 200 ° C., usually room temperature to 10 ° C.
About 0 ° C (liquid or vapor) and 10 seconds to 1 week,
Usually, the contact may be performed for about 1 minute to 1 day. It can also be brought into contact with water under pressure. The water may contain a wetting agent or a surfactant, a water-soluble organic solvent or the like to improve the wetting of the molded body. The water can be in the form of heated water vapor or moisture in the air in addition to ordinary water. In addition, the degree of crosslinking is generally preferably from 40 to 90% by weight.

(D) Conductivity The conductivity of the easily peelable semiconductive resin composition of the present invention is generally 10 ^-1 to 10 ^-4 Ω · cm, preferably 10 to 10 ³ Ω.
Cm and indicates a volume specific resistance value. The conductivity performance can be controlled by the amount of carbon black.

[II] Molding The easily peelable semiconductive resin composition of the present invention can be molded into a desired shape by a usual molding method, for example, film molding, coextrusion molding, calendar molding or the like. it can. In addition, the easily peelable semiconductive resin composition of the present invention can suitably utilize the feature of easy peelability by being laminated with another base material to form a laminate. As a mating base material constituting the laminate, a polyolefin-based resin is preferable.

[0037]

The present invention will be specifically described below with reference to examples and comparative examples. [I] Evaluation method Evaluation methods in Examples and Comparative Examples were performed as follows. (1) Peeling test A typical example of the test actually performed is L / D
26. The semiconductive resin composition was placed in a 20 mm caliber extruder,
/ D28, an ethylene / unsaturated silane compound copolymer as shown in Reference Example 1 or Reference Example 2
The unsaturated silane compound-grafted polyethylene shown below (hereinafter, both are collectively referred to as “silane-modified polyethylene”) is charged, and a two-layer co-extruded sheet is formed by a T-type two-layer molding machine at a die setting temperature of 190 ° C. to obtain a sample. Obtained. The condensation catalyst masterbatch shown in Reference Example 3 (described later) was dry-blended at a predetermined concentration and charged in the silane-modified polyethylene. The composition of the sheet is 1 mm for the semiconductive resin composition layer and 2 m for the silane-modified polyethylene layer.
m. The obtained two-layer sheet was immersed in hot water at 85 ° C. for 12 hours to perform a crosslinking treatment, and then a sample having a resin flow direction of 20 cm × 0.5 inch width was cut out, and the temperature was 23 ° C. and the humidity was 50%.
% In 180% atmosphere, peeling speed 200m
Peeling strength was determined by peeling at m / min.
Here, 2 kg / 0.5 inch or less was regarded as good peelability. In the peeling test, the presence or absence of the residue (carbon residue) of the semiconductive resin composition adhering to the silane-modified polyethylene layer was visually observed.

(2) Degree of Crosslinking Using xylene as a solvent, a sample was extracted at a boiling point temperature for about 12 hours by a Soxhlet extractor, and the weight of the unextracted residue was expressed in percentage according to the following formula. Degree of cross-linking (%) = [weight remaining after extraction (g) / weight of sample before extraction (g)] × 100

(3) Tensile strength Measured according to JIS-K7113.

(4) Heat-Pressure Deformation Rate A 30 × 20 mm test piece was cut from the semiconductive resin layer, set between pressure plates, and placed in a 120 ° C. atmosphere under a predetermined amount (1 kg) of a load. Pressure was applied to the test piece over time, the amount of change in the thickness of the test piece was determined using a dial gauge, and the heating / pressing deformation rate was calculated by the following equation. Heat and pressure deformation rate (%) = [Change in test specimen thickness (mm) / test specimen thickness (mm)] × 100

(5) Conductivity A test piece of 20 mm × 80 mm was cut out from the semiconductive resin layer, and the resistance was measured by a digital multimeter according to SRIS 2301. From this value, the resistivity per unit volume was calculated.

[II] Raw Materials Production examples of each raw material used in Examples and Comparative Examples are shown below. Reference Example 1 Production of Ethylene / Vinyltrimethoxysilane Copolymer Ethylene was added to a 1.5-liter reactor equipped with a stirrer.
Vinyltrimethoxysilane (hereinafter may be simply abbreviated as "VTMOS") as an unsaturated silane compound, and a mixture of propylene as a molecular weight regulator and t-butylperoxyisobutyrate as a radical generator Were continuously reacted while being supplied under the following conditions. Supply amount Ethylene 43 kg / h Vinyl trimethoxysilane 0.20 kg / h Propylene 0.45 kg / h t-butyl peroxyisobutyrate 2.3 g / h Supply monomer temperature 65 ° C Polymerization pressure 2,400 kg / cm ² Reaction maximum Temperature: 225 ° C. Production: 5.5 kg / hour The obtained ethylene / VTMOS copolymer has a density of 0.9.
23g / cm ³ , MFR 0.9g / 10min, VTMOS
The content was 1.2% by weight, and the gel fraction after crosslinking treatment was 78%.

Reference Example 2 : Production of vinyltrimethoxysilane-grafted polyethylene Unsaturated silane compound-grafted polyethylene had a density of 0.
100 parts by weight of low-density polyethylene of 919 g / cm ³ and MFR of 2.0 g / 10 minutes, 2 parts by weight of VTMOS,
0.08 parts by weight of dicumyl peroxide is L / D28,
The graft reaction was carried out in a single-screw extruder having a diameter of 40 mm under the conditions of a temperature of 190 ° C. and a residence time of 1.7 minutes. V obtained
TMOS-grafted polyethylene has a density of 0.920 g /
cm ³ , MFR 0.8 g / 10 min, VTMOS content 1.
The gel fraction after cross-linking was 2% by weight and 75%.

Reference Example 3 Production of Silanol Condensation Catalyst Masterbatch With respect to 100 parts by weight of polyethylene having a density of 0.919 g / cm ³ and MFR of 2.0 g / 10 minutes, 1 part by weight of dibutyltin dilaurate and 4,4′-thio- Bis (2-t-butyl-m-cresol) 1 part by weight, 2,2′-oxamide-
1 part by weight of bis- [ethyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and 1 part by weight of zinc stearate were added at a temperature of 180 ° C. under a residence time of 0.7 minutes. Uniform dispersion was carried out using a shaft kneader to obtain a silanol condensation catalyst master batch having a density of 0.925 g / cm ³ , a MFR of 3.0 g / 10 min, and a catalyst concentration of 1% by weight.

Reference Example 4 Production of Styrene-Modified Ethylene-Vinyl Acetate Copolymer 20 kg of pure water in an autoclave having an internal volume of 50 liters
An aqueous medium was prepared by adding 600 g of tribasic calcium phosphate and 0.6 g of sodium dodecylbenzenesulfonate as a suspending agent, and an ethylene / vinyl acetate copolymer (vinyl acetate content: 33% by weight, MFR: 30 g / 10 minutes)
6 kg of 3 mm diameter particles were suspended by stirring. Separately, 8 g of benzoyl peroxide and 4 g of t-butylperoxybenzoate were added as polymerization initiators to 6 kg of styrene (ethylene
1 to 100 parts by weight of vinyl acetate copolymer (EVA)
Of the autoclave, the temperature in the autoclave is raised to 50 ° C., and the temperature is maintained for 3 hours to convert styrene containing the polymerization initiator into ethylene.
It was impregnated into vinyl acetate copolymer particles. The aqueous suspension was kept at 60 ° C. for 7 hours and at 85 ° C. for 5 hours to complete the polymerization. It was confirmed that in the obtained particles of the styrene-modified ethylene / vinyl acetate copolymer, the styrene polymer was present in substantially the same amount as the quantitatively used styrene, that is, about 100 parts by weight.

Reference Example 5 : Production of styrene-modified ethylene / methyl acrylate copolymer Instead of the ethylene / vinyl acetate copolymer used in Reference Example 4, an ethylene / methyl acrylate copolymer (methyl acrylate content 20% by weight, MFR 15g / 10
In the same manner as in Reference Example 4, except that the above-mentioned (Example) was used, a modified ethylene / methyl acrylate copolymer was obtained.

Reference Example 6 Production of Styrene-Modified Ethylene / Butyl Acrylate Copolymer Instead of the ethylene / vinyl acetate copolymer used in Reference Example 4, an ethylene / butyl acrylate copolymer (butyl acrylate content 24% by weight, MFR 20g / 10
In the same manner as in Reference Example 4, except that the above-mentioned (Example) was used, a modified ethylene / butyl acrylate copolymer was obtained.

Reference Example 7 Production of Ethylene-Vinyltrimethoxysilane-Methyl Acrylate Copolymer Ethylene was placed in a 1.5-liter reactor equipped with a stirrer.
A mixture of VTMOS, methyl acrylate and propylene as a chain transfer agent and t-butyl peroxyisobutyrate as a radical generator were continuously reacted while supplying them under the following conditions. Supply amount Ethylene 32.1 kg / h Vinyl trimethoxysilane 0.15 kg / h Methyl acrylate 0.76 kg / h Propylene 0.45 kg / h t-butyl peroxyisobutyrate 8.2 g / h Supply monomer temperature 80 ° C Polymerization pressure 2,000 kg / cm ² Maximum reaction temperature 190 ° C. Production amount 5.5 kg / h The obtained ethylene / VTMOS / methyl acrylate copolymer has an MFR of 10 g / 10 min, a VTMOS content of 1.4% by weight, and methyl acrylate. The content was 30% by weight, and the gel fraction after crosslinking treatment was 72%.

Reference Example 8 : Production of ethylene / γ-methacryloxypropyltrimethoxysilane / methyl acrylate copolymer Instead of VTMOS used in Reference Example 7, γ-methacryloxypropyltrimethoxysilane (hereinafter simply referred to as “ γ-MPTMS ”).
An ethylene / γ-MPTMS / methyl acrylate copolymer was obtained in the same manner as in Reference Example 7, except that the mixture was fed at a rate of 52 kg / hour. The obtained ethylene-γ-MPTMS
The methyl acrylate copolymer has an MFR of 10 g / 10 minutes,
The γ-MPTMS content was 1.7% by weight, the methyl acrylate content was 20% by weight, and the gel fraction after the crosslinking treatment was 81%.

Reference Example 9 : Production of ethylene / vinyltrimethoxysilane / vinyl acetate copolymer (1) In place of methyl acrylate used in Reference Example 7,
An ethylene / VTMOS / vinyl acetate copolymer (1) was obtained in the same manner as in Reference Example 7, except that vinyl acetate was fed at a rate of 5.3 kg / hour. Ethylene VTM obtained
OS / vinyl acetate copolymer (1) has an MFR of 20 g / 1
0 minutes, VTMOS content 1.4% by weight, vinyl acetate content 2
The gel fraction after cross-linking was 5% by weight and 70%.

Reference Example 10 : Production of ethylene / vinyltrimethoxysilane / vinyl acetate copolymer (2) In place of methyl acrylate used in Reference Example 7,
5.3 kg / h of vinyl acetate and 0.02 k of VTMOS
An ethylene / VTMOS / vinyl acetate copolymer (2) was obtained in the same manner as in Reference Example 7, except that the mixture was fed at a rate of g / hour. The obtained ethylene / VTMOS / vinyl acetate copolymer (2) had an MFR of 10 g / 10 min, a VTMOS content of 0.1% by weight, a vinyl acetate content of 27% by weight, and a gel fraction after crosslinking treatment of 15%. .

Reference Example 11 Production of Ethylene / VTMOS / Butyl Acrylate Copolymer Instead of methyl acrylate used in Reference Example 7,
Except that butyl acrylate was fed at a rate of 0.8 kg / hr, ethylene / VTMOS /
A butyl acrylate copolymer was obtained. The obtained ethylene
VTMOS / butyl acrylate copolymer has MFR10
g / 10 min, VTMOS content 1.5% by weight, butyl acrylate content 27% by weight, gel fraction after crosslinking treatment is 70%
Met.

[III] Experimental Example Example 1 First, 40 parts by weight of the styrene-modified ethylene / methyl acrylate copolymer shown in Reference Example 5 and ethylene vinyltrimethoxysilane (VTMOS) shown in Reference Example 7・
100 parts by weight of a resin component comprising 60 parts by weight of a methyl acrylate copolymer, and 40 parts by weight of furnace carbon ("Vulcan XC72" manufactured by Cabot Corporation: DBP [dibutyl phthalate] oil absorption 178 cc / 100 g) were used, and the screw diameter was 45 mm. Using the same direction twin screw extruder,
Temperature 180 ° C, rotation speed 250rpm, discharge amount 20kg /
The mixture was melt-kneaded under the conditions described above to produce a semiconductive resin composition. Next, this semiconductive resin composition was charged into an L / D 26, 20 mm diameter extruder, while an L / D 28, 3 mm diameter
To a 0 mm extruder, 100 parts by weight of the ethylene / VTMOS copolymer shown in Reference Example 1 and 5 parts by weight of a master batch of silanol condensation catalyst shown in Reference Example 3 were dry-blended and fed as a mating base material, and T-type two-layer molding was performed. The temperature of the die was set to 190 ° C. by a machine, and two-layer coextruded sheets were formed to obtain a sheet-like sample. Further, the obtained sheet-shaped sample was immersed in hot water at a temperature of 85 ° C. for 12 hours, crosslinked and dried, and then evaluated. The results are shown in Table 1. There is no carbon residue, and 2kg /
Good results of 0.5 inch or less were obtained.

Example 2 Ethylene V used as a mating substrate in Example 1
A sample was produced in the same manner as in Example 1 except that the VTMOS grafted polyethylene shown in Reference Example 2 was used instead of the TMOS / methyl acrylate copolymer.
The same evaluation was performed. Table 1 shows the results.

Example 3 In place of the ethylene / VTMOS / methyl acrylate copolymer used in Example 1, 60 parts by weight of the ethylene / γ-MPTMS / methyl acrylate copolymer shown in Reference Example 8 was used. Except for the above, a sample was manufactured in the same manner as in Example 1, and the same evaluation was performed. Table 1 shows the results.
Shown in

Example 4 Instead of the styrene-modified ethylene / methyl acrylate copolymer shown in Reference Example 5 used in Example 1, a styrene-modified ethylene-vinyl acetate copolymer 4 shown in Reference Example 4 was used.
0 parts by weight, and instead of ethylene / VTMOS / methyl acrylate copolymer, ethylene / V shown in Reference Example 9
A sample was produced in the same manner as in Example 1 except that 60 parts by weight of the TMOS / vinyl acetate copolymer (1) was used, and the same evaluation was performed. Table 1 shows the results.

[0057] Example in place of the styrene-modified ethylene-methyl acrylate copolymer in Reference Example 5 was used in 5 Example 1, styrene-modified ethylene-butyl acrylate copolymer 40 weight shown in Reference Example 6 The same procedure as in Example 1 was conducted except that 60 parts by weight of the ethylene / VTMOS / butyl acrylate copolymer shown in Reference Example 11 was used instead of the ethylene / VTMOS / methyl acrylate copolymer. A sample was manufactured by the technique and the same evaluation was performed. Table 1 shows the results.

Example 6 A sample was prepared in the same manner as in Example 1 except that 0.3% by weight of hexyltrimethoxysilane was added when molding the semiconductive resin composition. It was manufactured and subjected to the same evaluation. Table 1 shows the results.

Comparative Example 1 The procedure of Example 1 was repeated, except that 60 parts by weight of the ethylene / VTMOS / methyl acrylate copolymer used in Example 1 was replaced by 60 parts by weight of the ethylene / VTMOS copolymer shown in Reference Example 1. A sample was manufactured in the same manner as in Example 1,
The same evaluation was performed. Table 2 shows the results.

Comparative Example 2 Instead of 60 parts by weight of the ethylene / VTMOS / methyl acrylate copolymer used in Example 1, Reference Example 10 was used.
A sample was produced in the same manner as in Example 1 except that 60 parts by weight of the ethylene / VTMOS / vinyl acetate copolymer (2) shown in (1) was used, and the same evaluation was performed. Table 2 shows the results.

Comparative Example 3 The procedure of Example 1 was repeated except that the mixing ratio was changed to 95 parts by weight of ethylene / VTMOS / methyl acrylate copolymer and 5 parts by weight of styrene-modified ethylene / methyl acrylate copolymer. A sample was manufactured in the same manner as in Example 1, and the same evaluation was performed. Table 2 shows the results.

Comparative Example 4 Example 1 was repeated except that the mixing ratio was changed to 10 parts by weight of the ethylene / VTMOS / methyl acrylate copolymer and 90 parts by weight of the styrene-modified ethylene / methyl acrylate copolymer. A sample was manufactured in the same manner as in Example 1, and the same evaluation was performed. Table 2 shows the results.

[0063]

[Table 1]

[0064]

[Table 2]

[0065]

The easily peelable semiconductive resin composition of the present invention comprises a modified ethylene copolymer, an ethylene / unsaturated silane compound / ethylenically unsaturated compound copolymer, and carbon black as main components. By using a material that combines good mechanical strength, heat resistance and moderate peel strength,
The cross-linking process is simple and the productivity is high, extrudability and semi-conductivity are excellent, peeling is easy in connection between cables, it is not cut at the time of peeling, and it is applied to the inner and outer layers of the insulating layer for the purpose of relaxing the electric field It is useful as a type of power cable provided with a semiconductive layer.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Jijio 1 Tohocho, Yokkaichi-shi, Mie Prefecture Inside Yokkaichi Research Institute, Mitsubishi Chemical Corporation

Claims (5)

[Claims] An easily peelable semiconductive resin composition comprising the following components (A), (B) and (C). Here, the compounding amount of the component (C) is
And component (B) based on 100 parts by weight in total. Component (A): Modified ethylene copolymer obtained by subjecting ethylene copolymer (a1) and vinyl monomer (a2) to graft polymerization conditions 10 to 80 parts by weight Component (B): ethylene general formula RSiR' _n Y _3-n olefin emissions unsaturated silane compound represented by a copolymer 90 to 20 parts by weight of an ethylenically unsaturated compound (wherein, R is a hydrocarbyl group having an ethylenically unsaturated or Represents a hydrocarbyloxy group, R ′ represents an aliphatic saturated hydrocarbyl group, Y represents a hydrolyzable organic group, and n is 0, 1, or 2.) Component (C): 10 to 110 weight of carbon black Department 2. An ethylene copolymer (a) in component (A)
1) the content of a comonomer copolymerized with ethylene is 20 to
The easily peelable semiconductive resin composition according to claim 1, which is 50% by weight. 3. An ethylene copolymer (a) in component (A).
The easily peelable semiconductive resin composition according to claim 1, wherein 1) is a copolymer having a melt flow rate of 0.1 to 300 g / 10 minutes. 4. The easily peelable semiconductive resin composition according to claim 1, wherein the component (A) contains 10 to 60% by weight of a vinyl monomer (a2) unit. 5. The easily peelable semiconductive resin composition according to claim 1, wherein the vinyl monomer (a2) is an aromatic vinyl monomer.