JPS5880210A - Crosslinked polyethylene cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a crosslinked polyethylene cable having a peelable outer chiroelectric layer.

In recent years, when connecting and terminal-treating cross-linked polyethylene cables, in order to make the external semiconducting layer into a material, vinyl chloride, ethylene-vinyl-vinyl copolymer, chlorinated polyethylene, etc. are being used as main materials. It has been proposed to use a composition made of

However, since the purpose of the above method is only to reduce the peel strength with the crosslinked polyethylene insulator, when actually stripping the cable, as a preliminary step, 1) External 2) Make two or more woven scratches on the 4wL layer using a knife or the like so that it does not look like an insulator, or 2) Add a spiral shape to the outer semiconductor layer using a special jig (not shown) with a built-in sharp knife. Nine methods are used, such as attaching a togaki to the name.

However, although these preliminary works are relatively simple in the case of 1), there is a high risk of accidentally damaging the insulator, which can cause fatal damage to the cable and reduce the reliability of the construction, resulting in damage to the external half. There are disadvantages such as the fact that the thickness of 4 [7 m] cannot be reduced beyond a certain level, which is disadvantageous in terms of material reduction and cable volume. In the case of 2), ■ a special dedicated jig is required, ■ the preparatory stripping process takes too much time and is inefficient, and ■ the insulator will still remain if the jig is not carefully adjusted. However, there is a risk that the outer S semiconducting layer may be damaged, and as a result, the thickness of the outer S semiconducting layer cannot be made thinner, which is a disadvantage.

As described above, the peelable outer semiconducting layer in conventional cross-linked polyethylene cables has many drawbacks in connection ffm, and therefore, for example, 6KV--GV
4! The reason for the delay in practical application is the lumpy form.

The present invention has been made in view of the above-mentioned points.
A cross-linked polyethylene/cable T-layer that can easily peel off the outer 4kJt layer in a spiral shape with just the force of a fingertip, without the conventional pre-injection nest when peeling off the U-. The purpose is to

In other words, the claim of non-invention is that the cable is formed by blending conductive carbon black and a cross-linking agent with a mixed proboscis mainly composed of an olefin dish combination or an olefin electrocombination, and has a peelable outer semiconductive layer. The peelable outer semiconducting layer in the peelable outer semiconducting layer with the inner cross-polyethylene
Vt≦20, where the thickness is t-1 and the thickness of the external semiconducting layer is t-1.
1, and the extension wing at the time of tearing of the outer semiconducting layer satisfies 1.0 cm≦X≦4.03.

Examples of the olefin polymer used in the present invention include polyethylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, and ethylene 1! f): &Vinyl copolymer, ethylene-ethyl acrylate copolymer, and the like.

In addition, as the conductive carbon black, acetylene black, furnace black, and other commercially available products are suitably used.
It is preferably 10 to 10 parts by weight, particularly 30 to 10 parts by weight, based on the negative part.

Additionally, the crosslinking agent may be an organic peroxide, such as dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)-hexane, 2,5-dimethyl-2,S
Di(t-butylperoxy)-hexyne-3,1,3-
Bis(t-butylperoxyisopropyl)benzene and the like are preferred.

In the present invention, the elongated wings of the peelable outer semiconductive layer at tear rupture are 1.0 cm≦! ≦40a11 and 9 is that if the elongation of the outer semiconducting layer is less than 1.0 mm, it is easy to tear in directions other than the intended peeling direction when peeling in a spiral shape etc. with fingertip force. This is because continuous peeling becomes difficult, and if ocyn t occurs, the material may tear even if you try to peel it off in a spiral shape without using a knife, etc., as shown in 4. I'm worried that it will continue to grow and make stripping 9 impossible. 91 The relationship between the peel strength with the insulator (Kf/115■ width) and the thickness t (■) of the external semiconducting layer is M/l > 20, the peeling Kl'
As the force increases, the outer semiconducting layer becomes susceptible to material destruction and breakage.

When manufacturing the crosslinked polyethylene cable of the present invention, the p-in S insulator and the outer semiconducting layer are co-extruded by a conventional method, or after the insulator is extruded,
Although any method for forming the outer semiconductive layer can be used, temporary extrusion is preferred from the standpoint of cable quality control and work efficiency. For crosslinking of the extruded nine cores, a heating step using steam, inert gas, etc. as a medium is added after the extrusion of one culm.

Next, the present invention will be specifically explained with reference to Examples.

The figure shows a cross-sectional view of a cross-linked polyethylene cable, in which 1 is a conductor, 2 is a conventionally known inner semiconducting layer, 3 is a cross-polyethylene insulator, and 4 is a peelable outer semiconducting layer. has the composition and thickness shown in each example and comparative example in the following table, and is formed by coextrusion with an internal semiconducting layer and an insulator on a conductor, and then crosslinked in heated steam at 20 atmospheres. .

The peel strength in the table is 1 from cross-linked polyethylene insulation.
This is the force required to peel off a 15 m wide piece of external semiconducting layer, and the test method was in accordance with the American standard Mutei IC, c85-71. In addition, the elongation at tear rupture (work) is determined by JI8 6301 for the external semiconductive layer peeled off from the crosslinked polyethylene insulator.
A test piece punched out with a dumbbell according to
It was made to tear and break at a tensile rate of -1=, and the elongation at break was determined. Furthermore, the evaluation of spiral stripping properties with fingertips shows the evaluation when the outer semiconductive layer of a cable core with a length of about 30mm was peeled off in a spiral shape with a width of about 3mm using only the force of a fingertip. be.

As is clear from the table, all of the peelable outer semiconductive layers according to the present invention simultaneously satisfy the following conditions: m/l≦20.1.03≦X≦4 and 0 countries.

As described above, the present invention provides a peelable outer semiconducting layer tN tip 5.
Since it can be easily peeled off continuously in a spiral shape using the force of fIL, the efficiency of fII at the connection and terminal parts of the couple is dramatically improved. No more damage to the 9
In addition, the reliability of its quality can be improved, and the thickness of the external semiconducting layer can be made thinner, which not only reduces the amount of material used but also reduces the cable volume. Can be done.

[Brief explanation of drawings]

The figure is a sectional view of a crosslinked polyethylene cable according to the present invention. DESCRIPTION OF SYMBOLS 1... Conductor, 2... Inner semiconducting layer, 3... Insulator, 4... Peelable outer semiconducting layer. Patent applicant Yazaki Sogyo Co., Ltd.

Claims (1)

[Claims] In a cable having a peelable external chiroelectric layer formed by blending conductive carbon black and a crosslinking agent with a mixture mainly composed of an olefin polymer or an olefin polymer,
The peelable outer semiconducting layer satisfies the peel strength with respect to the internal crosslinked polyethylene insulator (mu), the thickness of the outer semiconducting layer (mu), and the thickness of the outer semiconducting layer (mu/l≦20t). M
! A cross-linked polyethylene cable with an extended wing length of 1 and Otyar≦X≦4.03 as a 1-w image.