JP2001006446A - Cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve water repulsion, chemical resistant, flame resistant characteristics by providing a plastic sheath and a water layer are integrally fused on the outer circumference of a core, the laminated tape layer being provided with a laminated tape having a thermal fusion layer on its Al tape of a specified thickness with the thermal fusion layer disposed toward the outside, the plastic sheath being layed just on the water barrier layer to cover the same. SOLUTION: On a cable core 1, a wire shield 6 is disposed, and thereon a laminated tape 7 having a thermal fusion layer at one surface of its Al tape whose thickness is 0.001-0.03 mm is disposed with the thermal fusion layer arranged to face the outside, and thereby a water barrier layer is formed. On the lower barrier layer a plastic sheath 8 is layed to cover the same and integrally fused with the laminated tape 7 through the thermal fusion layer. Preferably, thermoplastic resin composition of nonhologen type having an olefin polymer as its base polymer is used as the material constituting the plastic sheath 8. Accordingly, generation of harmful gas at the baking time is prevented and also recycling is made easy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable in which a waterproof layer made of a laminated tape and a plastic sheath are sequentially provided on the outer periphery of a cable core, and more particularly to a cable having improved environmental preservation.

[0002]

2. Description of the Related Art Conventionally, in a high-pressure CV cable, in order to prevent water and chemicals from penetrating into a cable core and to provide high flame retardancy, a lead tape as a water barrier layer is provided on the outside of the cable core. A laminated tape in which a polyethylene tape is laminated on one side is vertically attached so that the lead tape surface is on the inside (cable core side), and a sheath made of a vinyl chloride resin is provided on the laminated tape integrally with the laminated tape. ing.

[0003] In recent years, as the demand for preserving the global environment has increased, materials and materials can be recycled, and even when incinerated or buried, harmful halogen gas and dioxin are not generated. Has been required.

However, in the above cable,
The laminating tape and the sheath are fused and integrated, making separation difficult and poor in recyclability (for example, if the laminating tape is mechanically peeled off from the sheath, the tape will break, and Even if only lead is separated by physical means after pulverization in a lump, a considerable amount of lead fine powder is inevitably mixed into the sheath material, and it is difficult to reuse the lead.) In addition, lead is harmful to the human body, and the vinyl chloride resin forming the sheath also generates harmful gases and the like during combustion.

[0005] For this reason, a cable having high environmental preservation in place of the above-mentioned cable, that is, having excellent water-shielding properties, chemical resistance and flame retardancy, is capable of recycling materials, and can be incinerated or buried. There is a demand for a cable that does not generate harmful substances such as halogen gas and dioxin.

[0006]

As described above, in recent years, there has been a demand for wires and cables that are recyclable and do not generate harmful substances even when incinerated or buried, and have a low environmental impact. Conventional high-voltage cables have excellent water-blocking properties, chemical resistance, and flame retardancy, but they are difficult to recycle, and the lead that forms the water-blocking layer is harmful to the human body, and the vinyl chloride resin that forms the sheath There is also a problem that harmful substances are generated during combustion.

The present invention has been made in view of the above circumstances, and has excellent water barrier properties, chemical resistance and flame retardancy, good recyclability, high safety to the human body, and high combustion efficiency. An object of the present invention is to provide a cable which does not sometimes generate harmful substances and is excellent in environmental protection.

[0008]

According to the present invention, there is provided a cable comprising: a laminate tape having a heat-sealing layer on one side of an aluminum tape having a thickness of 0.001 mm to 0.03 mm on the outer periphery of a cable core; , And a plastic sheath that is coated and fused directly on the water-impervious layer.

In the cable having the above structure, the water-impervious layer is formed of a laminate tape having a heat-sealing layer on one side of a thin aluminum tape having a thickness of 0.001 mm to 0.03 mm, and is provided immediately above the tape. The plastic sheath used can be reused, and safety for the human body can be improved. In other words, this thickness is 0.001
Since the thin aluminum tape of mm to 0.03 mm is much thinner than the conventional, usually normal thickness of 0.03 mm to 0.10 mm lead tape, even if it is processed together with a plastic sheath, the aluminum mixed amount is small. A sufficiently reusable sheath material can be obtained. Also, aluminum is not harmful to the human body like lead, so safety is improved. In addition, this aluminum tape is not inferior to lead tape in terms of the water blocking performance, and the water blocking of the cable does not decrease.

If the thickness of the aluminum tape is less than 0.001 mm, the strength becomes insufficient, and there is a possibility that the aluminum tape is cut or buckled when being attached to the outer periphery of the cable core. If the thickness of the aluminum tape exceeds 0.03 mm, the amount of aluminum mixed into the sheath material during batch processing with the plastic sheath will increase, and the physical properties of the collected sheath material will decrease, making reuse difficult. Could be.

In the present invention, the plastic sheath is desirably made of a halogen-free thermoplastic resin composition, so that generation of harmful substances such as chlorine gas and dioxin during combustion can be reduced. As the halogen-free thermoplastic resin composition, a thermoplastic resin composition using an olefin-based polymer as a base polymer is particularly preferable because it is easy to recycle.

In the present invention, flame retardancy can be imparted by adding a flame retardant to the plastic sheath.

In the present invention, from the viewpoint of environmental conservation,
It is desirable that the heat-sealing layer of the laminate tape is also made of the non-halogen thermoplastic resin composition as described above.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing an example of a cable according to the present invention.

In FIG. 1, reference numeral 1 denotes a cable having a structure in which an insulator layer 4 made of crosslinked polyethylene or the like is provided on a conductor 2 via an inner semiconductive layer 3 and an outer semiconductive layer 5 is provided thereon. Shows the core.

On the cable core 1, there is provided a wire shield 6 formed by horizontally winding a large number of fine copper wires, and on one side of an aluminum tape having a thickness of 0.001 mm to 0.03 mm, However, a laminate tape 7 having a structure in which a heat-sealing layer having a thickness of about 0.005 mm to 0.3 mm is provided is attached by vertically attaching the heat-sealing layer to the outside to form a water-blocking layer.

A plastic sheath 8 is coated on the water-shielding layer, and is integrally fused with the laminate tape 7 via a heat-sealing layer.

As a plastic material constituting the plastic sheath 8, use of a non-halogen thermoplastic resin composition containing an olefin polymer as a base polymer prevents generation of harmful substances such as chlorine gas and dioxin during combustion. It is also desirable because it is easy to recycle.

The olefin polymers include low-density polyethylene (LDPE) and medium-density polyethylene (M
DPE), high density polyethylene (HDPE), very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), polypropylene, ethylene / propylene copolymer (EP), ethylene / propylene / diene terpolymer ( EPDM), ethylene / vinyl acetate copolymer (EVA), ethylene / ethyl acrylate copolymer (EEA), ethylene / methyl acrylate copolymer, ethylene / methacrylic acid copolymer, ethylene / methacrylic acid copolymer , Ethylene / ethyl methacrylate copolymer,
Examples include an ethylene / maleic acid copolymer. Further, a copolymer obtained by copolymerizing ethylene with an α-olefin such as propylene, butene, pentene, hexene, octene, or a cyclic olefin with a metallocene catalyst can also be used. These are used alone or in combination.

Such a halogen-free thermoplastic resin composition may contain, if necessary, an inorganic filler, a plasticizer, a softening agent, an antioxidant, a coloring agent, an oxidizing agent as long as the effects of the present invention are not impaired. Inhibitors, ultraviolet absorbers, lubricants, stabilizers and other additives can be added. As the inorganic filler, magnesium oxide, aluminum oxide, zirconium oxide, titanium oxide, silicon carbide, mica and the like, as the plasticizer, fatty acids such as stearic acid and oleic acid or metal salts thereof, and as the softener, Mineral oils, waxes, paraffins, and the like, and examples of antioxidants include esters and amides. The formulation of the inorganic filler
It has the effect of increasing the insulation resistance and making it easy to tear by hand when dismantling.

In the present invention, a flame retardant or a flame retardant auxiliary can be added to such a halogen-free thermoplastic resin composition for the purpose of imparting flame retardancy. Aluminum hydroxide, magnesium hydroxide,
A phosphorus-based flame retardant, a molybdenum-based flame retardant, a silicone-based flame retardant, and the like are used. Among them, a combination of aluminum hydroxide and magnesium hydroxide is desirable. Further, as the flame retardant aid, carbon black, zinc hydroxystannate, zinc oxide, silicone, phosphorus and the like are used.

When aluminum hydroxide and magnesium hydroxide are used in combination, the amount added to the resin component is desirably 50 to 300 parts by weight, preferably 100 to 200 parts by weight, per 100 parts by weight of the resin component. Is more desirable. If the added amount is less than 50 parts by weight, sufficient flame retardancy cannot be obtained even when used in combination with a flame retardant auxiliary, while if it exceeds 300 parts by weight, processing characteristics and mechanical properties are reduced.

These flame retardants and flame retardant auxiliaries are treated with a silane coupling agent, a titanate coupling agent, a higher fatty acid coupling agent or the like to increase the adhesion to the resin and improve the mechanical properties. You can also.

The material constituting the heat-sealing layer of the laminate tape 7 is not particularly limited. However, as in the case of the plastic sheath 8, a non-halogen-based material having an olefin polymer as a base polymer is used. Use of a thermoplastic resin composition is desirable because generation of harmful substances such as chlorine gas and dioxin during combustion is prevented.

In the cable thus constructed, the water-impervious layer is formed by the laminated tape 7 having a heat-sealing layer on one side of a thin aluminum tape having a thickness of 0.001 mm to 0.03 mm. As described in detail below, the plastic sheath 8 provided thereon can be collectively processed together with the laminate tape 7 and reused as a sheath material.

Moreover, since the laminated tape 7 has a water blocking performance comparable to that of a conventional lead laminated tape, the water blocking is also good.

Here, a method of recycling the plastic sheath 8 will be described.

First, the fused plastic sheath 8 is peeled off from the cable together with the laminate tape 7 and crushed. Next, washing with water and draining with a centrifugal separator are repeated once or more times to remove as much as possible the aluminum fine powder, and then kneaded again with a kneader to form pellets. The kneading machine is equipped with a filter for removing foreign substances, and the fine aluminum powder is also removed during the re-kneading process. Although the pellets thus obtained contain fine aluminum powder, the amount thereof is small, and the pellets have physical properties sufficiently usable as a sheath material, and can be reused.

[0030]

Next, the present invention will be described more specifically with reference to examples.

Example 1 A heat-sealing layer made of high-density polyethylene having a thickness of 0.10 mm was formed on one side of an aluminum tape having a thickness of 0.03 mm to obtain a laminated tape.

Next, this laminated tape was
1.0mm thick semiconductive layer made of semiconductive polyethylene, 9.0mm thick insulator layer made of crosslinked polyethylene, and 1.0mm made of semiconductive polyethylene.
A heat-sealing layer is applied vertically outward on a 66 kV class cable core provided with a thick external semiconductive layer in order, and 70 parts by weight of high-density polyethylene, ethylene / ethyl acrylate A compound obtained by mixing 30 parts by weight of the polymer and 100 parts by weight of magnesium hydroxide as a flame retardant was extrusion-coated so as to have an outer diameter of 51 mm to form a sheath having a thickness of 4.5 mm.

Subsequently, the sheath was peeled off from the obtained cable together with the laminating tape, pulverized, washed with water and drained with a centrifugal separator, and further kneaded with a kneader to form pellets.

The obtained pellets were extruded into a sheet and examined for physical properties. As a result, the tensile strength was 13.1 MPa and the elongation was 600%. The results of examining the physical properties by extruding the above sheath material into a sheet alone were as follows: tensile strength 11.5 MPa, elongation 458%
Met.

Example 2 As a laminate tape, a heat sealing layer made of low density polyethylene having a thickness of 0.02 mm was formed on one side of an aluminum tape having a thickness of 0.03 mm, and a high density polyethylene layer having a thickness of 0.1 mm was formed on the other side. m
A cable was manufactured in the same manner as in Example 1 except that a laminated tape having a m-thick semiconductive ethylene / ethyl acrylate copolymer layer formed thereon in order was used.

Subsequently, the sheath was peeled off from the obtained cable together with the laminating tape, crushed, washed with water and drained with a centrifugal separator, and further kneaded with a kneader to form pellets.

The pellets obtained were extruded into a sheet and examined for physical properties. As a result, the pellets had a tensile strength of 13.0 MPa and an elongation of 590%.

[0038]

As described above, according to the cable of the present invention, the plastic sheath can be recycled, the safety for the human body is improved, and
Excellent water shielding comparable to conventional cables can be obtained. When the plastic sheath is formed of a halogen-free thermoplastic resin composition, the generation of toxic substances during combustion can be suppressed, and the environmental preservation can be further improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a cable according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cable core 2 ... Conductor 3 ... Inner semiconductive layer 4 ... Insulator layer 5 ... Outer semiconductive layer 7 ... Laminating tape 8 ... Plastic sheath

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazumi Ito 2-1-1, Sakae Oda, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside Showa Electric Wire & Cable Co., Ltd. (72) Minoru Okashita 2 Sakae Oda, Kawasaki-ku, Kawasaki-shi, Kanagawa 1-1-1, Showa Electric Wire & Cable Co., Ltd. (72) Inventor Hajime Tanimoto 2-1-1, Sakae Oda, Kawasaki-ku, Kawasaki-city, Kanagawa Prefecture In-Showa Electric Wire & Cable Co., Ltd. (72) Inventor Eisuke Yamaguchi Kawasaki, Kawasaki-shi, Kanagawa 2-1-1 Oda Ward, Showa Electric Wire & Cable Co., Ltd. F-term (reference) 5G313 AB07 AB09 AB10 AC06 AC07 AD02 AD03 AE02 AE07 5G315 CA03 CA04 CB06 CB08 CC01 CC08 CD02 CD14

Claims (7)

[Claims] 1. A thickness of 0.001 mm or more around the outer periphery of the cable core.
A water-shielding layer having a heat-sealing layer attached to one side of a 0.03 mm aluminum tape and having the heat-sealing layer facing outward, and a water-shielding layer directly over the water-sealing layer, are integrally fused and bonded. A cable comprising: a plastic sheath comprising: 2. The cable according to claim 1, wherein the plastic sheath is made of a halogen-free thermoplastic resin composition. 3. The cable according to claim 1, wherein the non-halogen thermoplastic resin composition is a resin composition using an olefin polymer as a base polymer. A cable comprising a copolymer. 4. The cable according to claim 1, wherein the plastic sheath contains a flame retardant. 5. The electric wire / cable according to claim 4, wherein the flame retardant is aluminum hydroxide and / or magnesium hydroxide. 6. The cable according to claim 1, wherein the heat-sealing layer is made of a halogen-free thermoplastic resin composition. 7. The cable according to claim 6, wherein the non-halogen thermoplastic resin composition forming the heat-sealing layer is a resin composition containing an olefin polymer as a base polymer. .