JP2860839B2 - Power cable with separator layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to power cables.
More specifically, the present invention relates to a cable having a semiconductive layer having an ethylene-vinyl acetate copolymer (EVA) as a base polymer and a layer made of copper, in which discoloration and corrosion of the copper layer are suppressed. Regarding power cables.

[0002]

2. Description of the Related Art Conventionally, in a power cable, an outer semiconductive layer is formed by using a carbon black filling composition having an EVA as a base polymer. Usually, a layer (usually a copper tape layer) is provided. In this case, at the contact surface between the EVA and the copper layer, there are disadvantages such as the discoloration of the copper layer and the corrosion of the copper layer after a long time. However, power cables with a discolored copper layer have significantly impaired their commercial value, and power cables with a corroded copper layer cannot serve as external shields. There is a problem that occurs.

[0003] The present inventors have conceived of providing a separator layer between a semiconductive layer having an ethylene-vinyl acetate copolymer as a base polymer and a layer made of copper in order to solve such a problem. .

By the way, the following points can be mentioned as characteristics that the separator layer should satisfy. (1) The separator layer is provided relatively easily after the external semiconductive layer of the power cable is crosslinked. For this purpose, the material for the separator layer must be a liquid, a solution, a suspension, or the like, which can be formed by directly applying it to the external semiconductive layer. (2) In order to maintain the function as a separator for a long period of time, the compatibility with the semiconductive layer is low, that is, it is hardly absorbed by the semiconductive layer. (3) The material for the separator layer has an appropriate viscosity (preferably 10 to 5000 c at 25 ° C.) so that it can be easily applied.
St, more preferably 50-500 cSt).

[0005] An object of the present invention is to provide a power cable in which discoloration and corrosion in the copper layer are suppressed, and which has a separator layer having the above characteristics.

[0006]

According to the present invention, a silicone oil and 2- (N, N-dibutylamino) are added between a semiconductive layer having an ethylene-vinyl acetate copolymer as a base polymer and a layer made of copper. ) -4,6-dimercapto-1,3,5-
It is a power cable provided with a separator layer made of a composition comprising triazine.

In the present invention, the material of the separator layer includes silicone oil and 2- (N, N-dibutylamino) -4,6-dimercapto-1,3,5-triazine.
There are used in combined mixed. These components are generally oil-soluble, and as a material of the separator layer, it is easy to form a uniform layer having good wettability to the semiconductive layer to be applied,
Further, there is an advantage that it can be diluted with a paraffin or an aromatic organic solvent as required.

[0008] Silicone oil has a viscosity at 25 ° C.
Those having 10 to 5000 cSt, preferably 50 to 500 cSt are suitable, and have a refractive index at 25 ° C of 1.400 to 1.510, particularly
Those in the range of 1.420 to 1.500 are preferred.

Specific examples of suitable silicone oils are shown below (note that typical commercial products are shown in parentheses). Polydimethylsiloxane (Shin-Etsu Chemical KF96, KF92, Toray Dow Corning SH200), Polymethylphenylsiloxane (Shin-Etsu Chemical KF50, KF54, Toray Dow Corning SH510, SH55)
0, SH710, SH705), polymethyl hydrogen siloxane (Shin-Etsu Chemical KF99, Toray Dow Corning BY16-805) and the like.

[0010] separator layer, a composition obtained by mixing under heat the sheet recone oil and the triazine compound, EV
It is formed by coating on a semiconductive layer having A as a base polymer. <br/> content of the triazine compound in the composition, and 0.05~10w / v%.

[0011] The silicone oil and the triazine compound
That is in the composition, as other ingredients, such as lubricants such as stearic acid, softening agents such as paraffin, amine, antioxidant phenolic, benzene, toluene, aromatic organic solvents or benzophenone and xylene An ultraviolet inhibitor or the like can be added.

The above triazine compound is usually in the form of a powder.
And make it exist almost uniformly on the semiconductor layer.
Requires some kind of binder. Also triazine
The compound has an excellent effect in preventing copper discoloration due to acetic acid.
It has fruit but has poor water resistance. However, triage
By using the silicone compound as a composition with the silicone compound,
Superior copper inherent in triazine compounds
The function of preventing discoloration can be utilized. And Silicon
Based on the general non-volatility of oil
The radiator layer has the advantage of long life.

[0013]

The semiconductive layer in the power cable of the present invention is not particularly limited as long as EVA is used as a base polymer. EV as a resin component of the composition for a semiconductive layer
A, EV in which aromatic vinyl monomers such as styrene, divinylbenzene, α-methylstyrene and the like are grafted on EVA
A graft copolymer, ethylene ethyl acrylate graft copolymer, ethylene methyl acrylate graft copolymer and the like are exemplified. As a component other than resin, usually
A conductive carbon black and a crosslinking agent are blended. The formation of the semiconductive layer may be performed according to a conventional method. For example, the composition for a semiconductive layer is applied on an insulating layer,
Crosslink at ~ 300 ° C for 5-45 minutes to form a semiconductive layer.

[0015] In the power cables of the present invention, the separator layer is applied, for example, the composition itself or the composition of the liquid composition dissolved or suspended in a solvent, directly above outer semiconducting layer to EVA base polymer And a layer made of copper is formed on the separator layer by a means known per se.

[0016]

The present invention will be described in detail below with reference to examples and comparative examples. Examples 1 to 3 The following semiconductive layer composition was applied on a polyethylene insulating layer and crosslinked at 280 ° C. for 30 minutes to form an external semiconductive layer. Then, the following composition for a separator layer was applied. ,
It is left at room temperature for 24 hours and air-dried to form a separator. Then, a copper tape having a thickness of 0.1 mm and having a polished surface was applied on the separator layer to prepare a sample of the present invention.

Comparative Example 1 A comparative sample was prepared in the same manner as in the example except that no separator layer was provided.

After leaving each of the samples prepared in Examples 1 to 3 and Comparative Example 1 at 80 ° C. for 6 hours and 24 hours, the copper tape was peeled off and the surface was observed for discoloration. The evaluation was indicated by x when copper acetate was generated, and by ◎ when copper acetate was not generated and a sufficient rust-preventing effect was observed. Table 1 shows the results.

[Semiconductive layer composition] EVA copolymer (Note 1) 100 Conductive furnace black (Note 2) 40 Zinc stearate 1 Phenolic antioxidant (Note 3) 0.5 Crosslinker (Note 4) 0. 5 Note 1: Yucalon Eva X-700, manufactured by Mitsubishi Yuka Co .; vinyl acetate content 33% by weight, MFR = 30, density = 0.96 Note 2: Vaccan XC-72, manufactured by Cabot Corporation Note 3: 4, 4 ' -Thiobis (2-tert-butyl-5
-Methylphenol), manufactured by Ouchi Shinko Co., Ltd., Nocrack 30
0 Note 4: 1,3-bis- (tert-butylperoxyisopropyl) benzene, manufactured by Kayaku Nuuri, Parkadox-14

[Separator layer composition] Silicone oil (KF96, manufactured by Shin-Etsu Chemical Co., Ltd.)
(N, N-dibutylamino) -4,6-dimercapto-
5 g (composition A), 10 g (composition B) and 15 g (composition C) of 1,3,5-triazine were dissolved to obtain a separator layer composition .

[0021]

[Table 1]

[0022]

According to the power cable of the present invention, EV
The separator layer prevents contact between the acetic acid generated from A and the layer made of copper, and as a result, it has a specific effect that the discoloration and corrosion of the copper layer can be prevented as much as possible.

Further, the material for the separator layer provided in the present invention may be a liquid itself or a solution or suspension composition, and the material itself or the composition may be coated. When a material having a suitable viscosity is used, there is an advantage that the separator layer can be easily provided by directly applying the material on the semiconductive layer.

Further, since the silicone oil and the like have low compatibility with the semiconductive layer containing EVA as a base polymer, they are less likely to be absorbed by the semiconductive layer, and thus have the advantage that the above-mentioned effect is excellent in persistence.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01B 7/28 H01B 3 / 30,3 / 46 H01B 9/02

Claims (1)

(57) [Claims] 1. A method according to claim 1, wherein a silicone oil and 2- (N, N-dibutylamino) -4,6- are provided between a semiconductive layer having an ethylene-vinyl acetate copolymer as a base polymer and a layer made of copper.
Composition comprising dimercapto-1,3,5-triazine
Power cable provided with a separator layer made of a material .