JP2646446B2 - Insulated wire - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated wire which has excellent electrical properties, is highly resistant to trauma, and is flexible, and in particular, prevents the occurrence of wrinkles during bending.

[Conventional technology]

As a conventional electric wire of this type, there is known a double insulated electric wire in which an insulator such as polyolefin is provided on a conductor and an outer periphery thereof is coated with an aromatic polymer.

[Problem to be solved]

However, in such an insulated wire, the adhesion between the polyolefin in the inner layer and the aromatic polymer in the outer layer is poor, and therefore, there has been a problem that wrinkles are generated in the outer layer during bending.

Further, the aromatic polymer itself is a polymer having excellent trauma resistance, but has poor adhesion to the polyolefin in the inner layer, so that the effect of improving the trauma resistance in the case of an insulated wire is not so large in some cases.

This is because when the layer of the aromatic polymer is thin, it is difficult to obtain particularly excellent trauma resistance.

In addition, most of aromatic polymers are water-absorbing and have a relatively large saturated water absorption of 450 to 7000 ppm in the air at room temperature.
When water is supplied to the polymer containing polyolefin as the main component of the inner layer and power is applied for a long period of time, water tree and the like are generated in the inner layer polyolefin, which has a drawback such as inferior long-term power application characteristics. .

When we examined the occurrence of wrinkles during bending, the cause of wrinkles was that the adhesion between the polyolefin in the inner layer and the aromatic polymer in the outer layer was poor, and the aromatic polymer with a large flexural modulus during bending was poor in flexibility. It was found that it was not sufficiently bent and that a gap was generated between the inner layer and the outer layer.

Then, this invention aims at improving the adhesiveness of an inner layer and an outer layer, and preventing generation | occurrence | production of the wrinkle at the time of bending.

[Means for solving the problem]

In order to achieve the above object, the present invention provides an insulated wire in which an insulating layer mainly composed of polyolefin is provided on a conductor and an insulating layer mainly composed of an aromatic polymer is provided on the outer periphery of the conductor. At least (i) ethylene / ethyl acrylate maleic anhydride copolymer (ii) ethylene / methacrylic acid copolymer (iv) maleic anhydride grafted polyolefin (V) Ethylene / vinyl alcohol copolymer One or more ethylene copolymers were constituted.

[Action]

In the present invention, the adhesion between the inner layer and the outer layer was improved, and no wrinkling was observed during bending.

〔Example〕

 Hereinafter, preferred embodiments of the present invention will be described.

The drawing shows a cross section of an insulated wire, in which an insulating layer 2 mainly composed of polyolefin is applied on a conductor 1, and an insulating layer 3 mainly containing an aromatic polymer is applied on the outer periphery thereof. The insulating layer 2 comprises at least (i) an ethylene / ethyl acrylate / maleic anhydride copolymer (ii) an ethylene / acrylic acid copolymer (iii) an ethylene / methacrylic acid copolymer (iv) a maleic anhydride grafted polyolefin And (v) one or more ethylene / vinyl alcohol copolymers. Representative examples of these polymers (i) to (v) include: (i) Ethylene / ethyl acrylate / maleic anhydride copolymer Example) Common name E-EA-MAH “Bondane” (trade name) manufactured by Sumitomo Chemical Co., Ltd. (ii) Ethylene / acrylic acid copolymer Example) Nickname of EAA Mitsubishi Yuka, trade name "Yukaron EAA" (iii) Ethylene / methacrylic acid copolymer Example) Nickname of EMAA made by Mitsui DuPont, trade name "Nuclear" Example) Commonly known as Ionomer Dupont, trade name "Surlyn" EMAA cross-linked with metal ions (Na, Zn, etc.) (iv) Maleic anhydride-grafted polyolefin Example) Commonly known MAH-g-polyolefin Sumitomo Chemical "Sumifarm" Mitsui Petrochemical "Admer" Mitsubishi Yuka "Modic" (v) Ethylene. Vinyl alcohol copolymer Example) Commonly known as "EVAL EP" manufactured by E-VAL Crela Co. The insulating layer (inner layer) 2 containing a polyolefin containing such a polymer as a main component may be crosslinked if necessary. As a crosslinking method in this case, chemical crosslinking using an organic peroxide, silane crosslinking, electron beam irradiation crosslinking, or the like is used. The content of maleic anhydride, acrylic acid, and methacrylic acid contained in the insulating layer 2 containing polyolefin as the main component is preferably 0.05 to 20%, and if the content is 0.05% or less, the effect of improving adhesion is small, and If it exceeds 20%, the electrical characteristics will deteriorate.

The aromatic polymer forming the insulating layer 3 is polyphenylene oxide, polyether ketone, polyether ether ketone, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyetherimide, polyarylate, poly 4-methyl-1-pentene, polysulfone poly. It is selected from the group consisting of ether sulfone and aromatic polyamide. Preferred aromatic polymers are at least 250 ° C, especially at least 300
It is a crystalline polymer with a melting point of ° C.

Next, a comparison between Production Examples 1 to 10 of the present invention and Comparative Examples 1 and 2 is shown in the following table.

* Inner insulation thickness = 0.3mm Irradiated and crosslinked * Outer insulation thickness = 0.2mm * Polyethylene (LDPE MI = 0.2), E-EA-MAH (bondin), EAA (Yukaron EAA), EMAA (Nucrel 409), MAH -G-polyolefin (Admer), E-VAL (Eval EP-G110) * The water tree generation density in the table is as follows: 10KV, 1KH _Z × 3
Check the number of water trees with a size of 50μ or more after 0-day charging
* Bending was not observed for wrinkles, Δ was slightly observed for wrinkles, and X was notably observed for wrinkles. [Effect] As described above, the present invention In the case of (1), wrinkles could be prevented because of good adhesion between the insulating layers constituting the inner layer and the outer layer. In addition, since the inner layer contains a polar polymer, water is dispersed in the polar group, and it is possible to prevent water trees from being generated in an abnormal electric field portion, so that water tree resistance is improved. Furthermore, even when the outer layer of the aromatic polymer is thin (eg, 0.3 mm or less)
Since the outer layer is not easily peeled off because of good adhesion to the inner layer, trauma resistance is improved.

[Brief description of the drawings]

 The drawing is a sectional view of the insulated wire. 1 ... conductor, 2 ... insulating layer (inner layer), 3 ... insulating layer (outer layer).

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Isao Takahashi 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd. (72) Inventor Akira Yoshino 1-9 Futabacho, Numazu-shi, Shizuoka Fujikura Electric Wire & Cable Company (72) Inventor Setsuo Sugiyama 1-9 Futaba-cho, Numazu City, Shizuoka Prefecture Fujikura Electric Wire Co., Ltd. Numazu Plant (72) Inventor Motohisa Murayama 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd. Inside

Claims (3)

(57) [Claims] 1. An insulated wire comprising a conductor (1) on which an insulating layer (2) containing polyolefin as a main component is applied, and an outer periphery of which is provided with an insulating layer (3) containing an aromatic polymer as a main component. At least (i) ethylene / ethyl acrylate / maleic anhydride copolymer (ii) ethylene / acrylic acid copolymer (iii) ethylene / methacrylic acid copolymer (iv) maleic anhydride Acid-grafted polyolefin (v) An insulated wire comprising one or more ethylene / vinyl alcohol copolymers. 2. The method according to claim 1, wherein the content of maleic anhydride, acrylic acid and methacrylic acid contained in the insulating layer (2) containing polyolefin as a main component is 0.05 to 20%. Insulated wires. 3. An aromatic polymer comprising: polyphenylene oxide, polyether ketone, polyether ether ketone, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyetherimide, polyarylate, poly 4-methyl-
The insulated wire according to claim 1, wherein the wire is selected from the group consisting of 1-pentene, polysulfone, polyethersulfone, and aromatic polyamide.