JP3231414B2 - Semiconductive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductive composition. More specifically, the present invention relates to a semiconductive composition that can be suitably used as a material for forming an external semiconductive layer of a power cable such as a crosslinked polyethylene insulated power cable.

[0002]

2. Description of the Related Art In a power cable such as a crosslinked polyethylene insulated power cable, a semiconductive layer is usually disposed inside and outside an insulating layer covering a conductor. However, when connecting or terminating a cable, crosslinked polyethylene or crosslinked ethylene / propylene is used. The outer semiconductive layer is peeled off from the insulating layer made of copolymer rubber or the like. At this time, if the adhesion between the two layers is too strong, the peeling operation becomes difficult, or if the excessive peeling is performed, the insulating layer is damaged during the peeling operation, which is not preferable. On the other hand, when the cable is deformed by an external force, it is necessary that the insulating layer and the external semiconductive layer do not cause interface separation. For this reason, the external semiconductive layer needs to have both a proper peeling property and a proper adhesion to the insulating layer. Conventionally, many proposals have been made for resin compositions used for such purposes, but in addition to releasability and adhesion, various properties required for the external semiconductive layer, such as workability, flexibility, and low-temperature properties. When the overall evaluation was made, there were not many things that were satisfactory.

[0003]

The inventors of the present invention have conducted various studies based on the present situation. As a result, the following resin composition containing an ethylene / (meth) acrylate / carbon monoxide copolymer as one component has been obtained. It has been found that the conductive layer exhibits good properties. Therefore, an object of the present invention is to provide a semiconductive resin composition suitable as a material for forming an external semiconductive layer of a power cable.

[0004]

According to the present invention SUMMARY OF] ethylene (meth) acrylic acid ester-carbon monoxide copolymer (A) and 10 to 90 parts by weight, scan styrene-based polymer and α-
A semiconductive composition obtained by blending 5 to 100 parts by weight of conductive carbon black with 100 parts by weight of a resin component consisting of 90 to 10 parts by weight of a polymer (B) selected from the group consisting of olefin copolymers Is provided.

The ethylene / (meth) acrylate / carbon monoxide copolymer (A) used as one of the resin components of the semiconductive composition of the present invention is ethylene, (meth) acrylate and monoxide. Carbon can be obtained by random copolymerization under high temperature and high pressure using a radical initiator. Considering various properties as the semiconductive layer, ethylene is 50 to 95% by weight, particularly 50 to 90% by weight, (meth) acrylate is 2 to 40% by weight,
Especially 5 to 35% by weight, 1 to 30% by weight of carbon monoxide,
It is particularly preferable to use a polymer having a polymerization composition of 2 to 25% by weight.

[0006] Here, the (meth) acrylate means an acrylate or a methacrylate,
Specific examples include methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, ethyl methacrylate, and n-butyl methacrylate.

[0007] The (meth) acrylate content and carbon monoxide content of the copolymer (A) affect various properties such as releasability, adhesion, flexibility, low temperature properties, and dispersibility of carbon black. Things. That is, if the content of the (meth) acrylic acid ester is too small, the flexibility, low-temperature properties, and easy peelability are deteriorated, while if the content is too large, the mechanical properties are deteriorated. When the content of carbon monoxide is small, the film does not easily peel off, and when the amount is too large, the mechanical properties, elongation and the like tend to be insufficient. Copolymer (A)
Also, considering workability, peelability, etc., the melt flow rate is 1 to 100 g / 10 min (190 ° C., 2
It is preferable to use one having a load of about 160 g).

[0008] In the present invention, as the other component constituting the resin component with the copolymer (A), the polymer selected from the group consisting of scan styrene polymer and α- olefin copolymer (B) Used.

[0009]

[0010]

Examples of the styrene polymer include polystyrene, high impact polystyrene, styrene / butadiene copolymer, and styrene / acrylonitrile copolymer.

The α-olefin copolymer has 3 carbon atoms.
It is preferable to use a copolymer having the above-mentioned α-olefin as a main component and having a melting point of about 75 to 140 ° C. More specifically, propylene and α having 4 or more carbon atoms
-Olefins, such as 1-butene, 1-hexene, 1-
Copolymers with octene, 4-methyl-1-pentene and the like can be mentioned as preferred examples. Such an α-olefin copolymer includes a melt flow rate (23
It is preferable to use a material having a load of 0 ° C. and a load of 2160 g) of about 1 to 100 g / 10 minutes.

[0013] Ethylene (meth) acrylate
The mixing ratio of the carbon monoxide copolymer (A) and the polymer (B) selected from the group consisting of a halogen-containing polymer, a styrene-based polymer and an α-olefin copolymer is such that the copolymer (A) The preferred range varies depending on the composition and the type of the polymer (B), but generally the former is 10 to 90 parts by weight, and the latter is 90 to 10 parts by weight, preferably the former 20 to 8 parts.
The latter is preferably 80 to 20 parts by weight with respect to 0 parts by weight.

In the present invention, based on 100 parts by weight of the resin component comprising the copolymer (A) and the polymer (B),
The conductive carbon black is blended at a ratio of 5 to 100 parts by weight. As the conductive carbon black, known materials such as acetylene black and furnace black can be used, and the amount thereof is determined in consideration of the conductivity required for the external semiconductive layer.

The semiconductive resin composition of the present invention may optionally contain a crosslinking agent, a crosslinking assistant, an antioxidant, a stabilizer and the like. Examples of the crosslinking agent include organic compounds such as dicumyl peroxide, 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexyne-3 and 1,3-bis (tert-butylperoxyisopropyl) benzene. A peroxide can be used, and is added in an amount of about 0.2 to 3 parts by weight per 100 parts by weight of the resin component.

The composition of the present invention can be prepared simultaneously or sequentially using a batch-type kneader such as a mixing roll, a Banbury mixer, a Brabender plastograph, or a pressure kneader, or a single-screw or twin-screw extruder. It can be carried out.

Although the semiconductive composition according to the present invention is used not only for surface heating elements but also for forming an external semiconductive layer of a crosslinked polyethylene insulated power cable for high voltage, etc., in this case, Co-extruded with the composition for the inner semiconductive layer and the composition for the insulating layer on the center conductor, or co-extruded with the composition for the insulating layer on the center conductor via the inner semiconductive layer To be served.

[0018]

EXAMPLES Table 1 shows raw material resin materials of resin components used in Examples and Comparative Examples. Table 2 shows conductive carbon black, a crosslinking agent, and the like added to the resin component.

[0019]

[Table 1]

[0020]

[Table 2]

Examples 1 to 5 The materials listed in Tables 1 and 2 were blended with the compositions shown in Table 3, and the resulting blend was adjusted to a surface temperature of 120 ° C.
The mixture was kneaded on an inch mixing roll to prepare a semiconductive composition.

Further, separately from the above, as a composition for an insulating layer,
A mixture obtained by adding 2 parts by weight of DCP and 0.2 part by weight of a stabilizer (Yoshinox SR) to 100 parts by weight of low-density polyethylene was kneaded and prepared on a 6-inch mixing roll also adjusted to a surface temperature of 120 ° C.

The composition for an insulating layer and the semiconductive composition thus obtained were each subjected to a press molding machine for 120 minutes.
After pressing at 120 ° C. for 3 minutes, 30 kg
/ Cm ² under a pressure of 3 minutes to perform temporary bonding. This temporary adhesive sheet was treated at 170 ° C., 30 kg / cm ² , 10
Press molding was performed under the conditions of minutes, to prepare a crosslinked bonded sample. This sample was cut to a width of 25 mm, and the insulating layer and the semiconductive layer were peeled off at a rate of 100 mm / min with a tensile tester, and the force required for the peeling was determined. Table 3 shows the results
It writes in.

[0024]

[Table 3]

[0025] [Comparative Examples 1-4] resin component, ethylene (meth) acrylic acid ester-carbon monoxide copolymer and scan Chile <br/> emissions based polymer in the above embodiment, alpha-olefin copolymerization Except that the ethylene / (meth) acrylate / carbon monoxide copolymer, ethylene / vinyl acetate copolymer and ethylene / ethyl acrylate copolymer shown in Table 3 were used alone in place of the mixture with the coalescing Prepared a semiconductive composition in the same manner as in Example, and measured the peel strength between the insulating layer and the semiconductive layer in the same manner as in Example 1. The results are shown in Table 3.

[0026]

When the semiconductive composition of the present invention is used as the outer semiconductive layer of the power cable, it has excellent adhesion to the crosslinked polyethylene insulating layer, but it is easy to peel off, so Terminal processing can be easily performed. Further, since it is excellent in flexibility, low-temperature characteristics, workability and the like, it is suitable as a material for forming an external semiconductive layer.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI H01B 9/02 H01B 9/02 B (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 73/00-73 / 02 C08K 3/04 C08L 23/02-23/24 C08L 25/04-25/14 H01B 1/24 H01B 9/02 CA (STN)

Claims (1)

(57) [Claims] 1. A ethylene (meth) acrylic acid ester-carbon monoxide copolymer (A) and 10 to 90 parts by weight, the group consisting of the scan switch <br/> alkylene polymer and α- olefin copolymer 100 parts by weight of a resin component comprising 90 to 10 parts by weight of a polymer (B) selected from the group consisting of conductive carbon black 5
A semiconductive composition comprising 100 to 100 parts by weight.