JPH04162308A - Hollow polyolefin insulated wire - Google Patents

Abstract

PURPOSE:To prevent the contraction of an insulator due to heating and facilitate the terminal treatment by longitudinally attaching a tape composed of a conductive metal foil layer and an organic polymer layer to a hollow polyolefin insulator in the manner that the organic polymer faces the insulator and electrically conducting the metal foil of the tape and a metal braided shield layer. CONSTITUTION:A metal braided shield layer 4 is provided on a hollow polyolefin insulator 2 having a built-in conductor 1 and further an organic polymer jacket 5 is provided thereon. A tape 3 composed of a conductive metal foil layer 32 and an organic polymer layer 33 is longitudinally attached to the hollow polyolefin insulator 2 facing the organic polymer layer 33, and the metal foil 32 and metal braided shield layer 4 are electrically conducted. Thereby, even when heating is carried out during use, contraction is obstructed by binding action of the metal foil 32, and since the tape 3 and the insulator 2 are not bonded to each other, the peeling removal is easy. Accordingly, the terminal treatment is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hollow polyolefin insulated wire, and particularly to an insulated wire suitable as a feeder wire for a vehicle radio antenna.

[Conventional technology]

Conventionally, feeder wires for vehicle radio antennas have been put into practical use with a structure consisting of a hollow polyolefin insulator containing a conductor, a metal wire braided shield layer, and an organic polymer/molecular jacket on top of the hollow polyolefin insulator.

By the way, a hollow polyolefin insulator is used as the insulator of the above-mentioned insulated wire. This insulator is usually molded by extrusion, but the strain generated during extrusion remains, and when the feeder wire is heated during use, the insulator shrinks due to the residual strain. When this insulator contracts, a problem arises in that the metal wire braided shield layer and the conductor, or in the case of using a metal longitudinal tape, short-circuit between it and the conductor.

Therefore, the present inventors first developed an insulated wire that does not shrink even when the hollow polyolefin insulator is heated during use. with metal wire braided shielding layer,
Further, the structure has an organic polymer jacket on top of the hollow polyolefin insulator, and a conductive metal foil tape is vertically bonded directly above the hollow polyolefin insulator, and the metal foil of the tape and the metal braided sole layer are electrically connected. We have developed a hollow polyolefin insulated wire with a conductive structure. This insulated wire was certainly effective in solving the above problems, but because the hollow polyolefin insulator and the conductive metal foil tape applied on it are bonded together, it is difficult to process the ends of the wire. However, there are problems in that it takes a long time to peel and remove the conductive metal foil tape from the insulator, or that the insulator is damaged when removed using a knife.

[Issues that need to be solved]

In consideration of the above-mentioned circumstances, the object of the present invention is to develop a hollow polyolefin insulated wire that does not cause shrinkage of the hollow polyolefin insulator even if the insulator is heated during use, and which can be easily terminal-treated. That is.

[Means of problem solving]

The present inventors have determined that the shrinkage of the insulator can be achieved by simply vertically holding a tape consisting of a conductive metal foil layer and an organic polymer layer with the organic polymer layer facing the hollow polyolefin insulator without adhering it. We found a solution to this problem. Moreover, as a result, the tape and the insulator do not adhere to each other, so that they can be easily peeled off and removed, and therefore the end treatment is facilitated.

The present invention has a structure in which a metal wire braided shield layer is placed on a hollow polyolefin insulator containing a conductor, and an organic polymer jacket is further placed on top of the metal wire braided shield layer. A tape consisting of is vertically aligned with the organic polymer layer facing the hollow polyolefin insulator,
The present invention also proposes a hollow polyolefin insulated wire characterized in that the metal foil of the tape and the metal braided shield layer are electrically connected.

[Action and configuration]

FIG. 1 is a perspective view of an embodiment of the present invention;
The figure is a sectional view taken along the line X-X in FIG. 1.

In Figures 1 and 2, 1 is a polygonal type conductor, 2
is a hollow polyolefin insulator, 3 is a conductive metal foil tape vertically laid on the hollow polyolefin insulator, 4 is an annealed copper wire braided shield, and 5 is a jacket made of ordinary jacket material such as polyvinyl chloride or polyethylene. .

Examples of the polyolefin constituting the hollow polyolefin insulator 2 include polyethylene, polypropylene, polybutene-1, and the like.

The conductive metal foil tape 3 has conductive metal foils 32 such as aluminum or copper adhered to both sides of a core layer 31 made of an organic polymer such as polyester, nylon, polyolefin, or polyvinyl chloride, and further conductive metal foils 32 made of conductive metal such as aluminum or copper. It has a 4N structure with an organic polymer layer 33 on one surface of 32,
The organic polymer layer 33 is placed vertically on the side of the hollow polyolefin insulator 2, and the conductive metal foil layers in the overlapped portions of the tapes are adhered to each other by suitable adhesive means. In the present invention, the conductive metal foil layers in the tape overlapping portions do not necessarily need to be bonded to each other; rather, not bonding them together reduces manufacturing costs and facilitates cable terminal processing.

If the organic polymer layer 33 is placed vertically on the hollow polyolefin insulator 2 with good contact, even if the hollow polyolefin insulator 2 and the organic polymer layer 33 are not bonded together, a long The contact of the organic polymer layer 33 over the entire circumference of the hollow polyolefin insulator 2 with a large contact area generates a large sliding frictional force, and due to this frictional force, the hollow polyolefin insulator is entirely included in the tape 3. It is to be supported by the metal foil 32,
Even if a force is generated that tends to shrink due to heating during use, the restraining action of the metal foil 32 prevents the shrinkage.

Further, the outer side of the conductive metal foil tape 3 is a conductive metal foil 32.
The foil 32 and the annealed copper wire braided shield 4 are in electrical contact and conduction, exhibiting an excellent shielding effect.

In the present invention, the conductive metal foil tape 3 only needs to have a restraining effect on the hollow polyolefin insulator by the above-mentioned frictional force and the like, and also have the effect of being electrically conductive with the metal braided shield, and may have the above-mentioned 4N structure. Various other structures are also possible. The simplest structure may be a two-layer structure in which an organic polymer layer is provided on one side of a single sheet of conductive metal foil. However, in general, metal foil has the disadvantage of being easily wrinkled due to buckling when used alone, so in order to overcome this disadvantage, a conductive metal foil tape that is reinforced by adhering at least one layer of the core layer 31 is used. preferable. If the thickness of the conductive metal foil present in the conductive metal foil tape 3 is too small, the prevention effect against shrinkage of the insulator 2 may be insufficient. The total thickness of these (hereinafter the same), especially 5μ
A thickness of m or more is preferable.

For the reasons mentioned above, many organic polymers such as N33 can be used to form the organic polymer layer. For example, polyethylene, polypropylene, polybutene-1, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, etc. Polyolefin homopolymers or copolymers, soft or hard polyvinyl chloride, polyester, nylon, and other plastics, styrene.
Thermoplastic elastomers such as butadiene-styrene copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, polyolefin thermoplastic elastomer, natural rubber, isoprene rubber, butyl rubber, chloroprene rubber, styrene-butadiene-copolymer rubber , acrylonitrile rubber,
Rubbers such as epichlorohydrin rubber, ethylene-propylene-diene terpolymer rubber, ethylene-vinyl acetate copolymer rubber, or their low to high vulcanizates, ethylene-
Examples include hot-melt adhesive-based organic polymers such as ionic copolymers obtained by ionically crosslinking ethyl acrylate copolymers, polyamide resins, and polyester resins. In particular, the coefficient of static friction with the polyolefin constituting the hollow polyolefin insulator is 0.09 or more at room temperature,
Particularly preferred is one having a value of 0.1 or more. Furthermore, it is preferable to use a material that exhibits slight adhesion to the polyolefin insulator, even if it does not have adhesion to the polyolefin insulator, as long as it does not adversely affect terminal treatment. However, care must be taken when using excessively adhesive tapes such as commercially available adhesive vinyl tapes, as wrinkles may occur on the polyolefin insulator when the tape is applied vertically, making vertical application difficult. Otherwise, such excessively sticky materials are undesirable.

As mentioned above, the conductive metal foil layers in the overlapped portions of the tapes may be adhered to each other by an appropriate adhesive means if necessary. For example, when attaching the tape 3 vertically, adhesive may be applied to only the overlapped portions of the tapes for adhesion. However, an adhesive that exhibits good adhesion to the conductive metal foil 32 as an organic polymer constituting the organic polymer layer such as the layer 33, for example, the above-mentioned 7) melt type adhesive system. When manufacturing the hollow polyolefin insulated wire of the present invention, it is also preferable to bond only the conductive metal foil layers in the tape overlapping portions to each other with an adhesive organic polymer layer. Note that even when using the above-mentioned hot-melt adhesive-based organic polymers as the constituent material of the organic polymer layer, it is often better not to bond the conductive metal foil layers in the overlapped portions of the tapes.

〔Example〕

Example 1 Inner diameter 2.4 mm, outer diameter 3.4 mm, wall thickness 0. A 5mm polyethylene pipe was manufactured by extrusion molding, and this was
The hollow polyethylene insulator was cut into m-long pieces. A polygonal wire type conductor with an outer diameter of 1.6 mm was inserted inside this.

A 108 m thick aluminum alloy foil was adhered to both sides of a 25 μm thick polyester tape (Mylar tape was used), and a modified ethylene-vinyl acetate copolymer (trade name: Atmer) N was applied to one side of the negative aluminum alloy foil. existing 4
A layered tape was used and was placed vertically on top of the hollow polyethylene insulator. An annealed copper wire braided shield was formed by vertically attaching an annealed copper wire braided tape thereon in a conventional manner, and a polyvinyl chloride jacket was successively provided thereon by extrusion molding, thus producing a feeder wire for a vehicle radio antenna.

This feeder wire was subjected to a heat cycle test (heated at 80°C for 4 hours, then returned to room temperature and left for 30 minutes, then cooled at -40'C for 1.5 hours, returned to room temperature again for 30 minutes)
A heat cycle was carried out 10 times (one cycle was a step of leaving the wire for 1 minute), but the shrinkage length of the hollow polyethylene insulator at the end of the feeder wire was extremely small, 1 mm or less.

Example 2 Instead of the aluminum alloy foil tape used in Example 1,
Aluminum alloy foil with a thickness of 7 μm is adhered to both sides of a polyester tube (using Mylar tape) with a thickness of 30 μm, and modified ethylene is applied to one side of the aluminum alloy foil.
A feeder wire was obtained which differed only in the use of a four-layer tape having a vinyl acetate copolymer (trade name: Atomer) N, and was subjected to the same heat cycle test as above.

As a result, the shrinkage length of the hollow polyethylene insulator was 2 mm.

Example 3 Instead of the aluminum alloy foil tape used in Example 1,
2 with a layer of modified ethylene-vinyl acetate copolymer (trade name Atomer) on one side of a 50 μm thick pure aluminum foil.
Using a layered tape, a feeder line was obtained which differed only in that it was vertically laid on a hollow polyethylene insulator with the pure aluminum foil layer on the outside, and this feeder line was subjected to the same heat cycle test as above. As a result, the shrinkage length of the hollow polyethylene insulator was 4 mm.

Example 4 Instead of the aluminum alloy foil tape used in Example 1, 5 μm thick copper foil was adhered to both sides of a 40 μm thick polyvinyl chloride tape, and soft polyvinyl chloride was attached to one side of the copper foil. A feeder line was obtained which differed only in the use of a four-layered tape having a film layer, and was subjected to the same heat cycle test as above. As a result, the shrinkage length of the hollow polyethylene insulator was extremely small, 1 mm or less.

Example 5 Instead of the aluminum base gold foil tape used in Example 1,
A 7 μm thick aluminum alloy foil is adhered to both sides of a 30 μm thick polyester tape (Mylar tape is used), and one side of the aluminum alloy foil has a density of 0.915.
A feeder line was obtained which differed only in that a four-layer tape having a low density polyethylene layer of 100 mL was used and was subjected to the same heat cycle tests as above. As a result, the shrinkage length of the hollow polyethylene insulator was 2 mm.

Example 6 Instead of the aluminum base gold foil tape used in Example 1,
A 7 μm thick aluminum alloy foil was adhered to both sides of a 30 μm thick polyester tape (Mylar tape was used), and an ethylene-vinyl acetate copolymer with a vinyl acetate content of 28% by weight was attached to one side of the aluminum alloy foil. A feeder line was obtained that differed only in the use of a four-layer tape having layers of 1 and 2, and was subjected to the same heat cycle tests as described above. As a result, the shrinkage length of the hollow polyethylene insulator was 2 mm.

Example 7 Instead of the aluminum alloy foil tape used in Example 1,
5μ thick on both sides of 40μm thick PVC tape
Glue the copper foil of m, and one! Ethylene on one side of Pl foil
A feeder wire was obtained which differed only in the use of a four-layered tape having a layer of vinyl acetate-maleic acid copolymer (trade name: VMCH), and was subjected to the same heat cycle test as above. As a result, the shrinkage length of the hollow polyethylene insulator was extremely small, 1 mm or less.

In all of the above Examples 1 to 7, when a part of the cable was cooled to room temperature after manufacturing and disassembled, the hollow polyethylene insulator and the modified ethylene of the polyester tape were removed.
Although it adhered well to the vinyl acetate copolymer layer, it was not adhered or fused. Furthermore, the conductive metal 7M layers at the tape overlapping portions were not adhered to each other.

Comparative Example 1 What is a feeder wire? A feeder wire that differs from Example 1 only in that the four-layered tape described above was not used and a single flat shield of annealed copper wire was provided directly above the insulator in hollow polyethylene was obtained, and this was different from the above. The same heat cycle test was performed. As a result, the shrinkage length of the hollow polyethylene insulator was as large as 180 mm.

Comparative Example 2 What is the aluminum base gold foil tape used in Example 1? This is an example only in that a three-layer tape with no modified ethylene-vinyl acetate copolymer (trade name Atomer) N on one side of the aluminum alloy foil was used. A feeder wire different from No. 1 was obtained and subjected to the same heat cycle test as above. As a result, the shrinkage length of the hollow polyethylene insulator was as large as 250 mm.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the present invention, and FIG. 2 is a sectional view taken along line X--X in FIG. 1 Broken wire type conductor 2 Hollow polyethylene insulator 3 Conductive metal foil tape 31 Core layer 32 Conductive metal foil 33 Organic polymer layer 4 Annealed copper wire braided shield 5 Jacket (and above) Patent applicant Mitsubishi Cable Industries, Ltd.

Claims (3)

[Claims] (1) A tape consisting of a conductive metal foil layer and an organic polymer layer, with a metal wire braided shield layer on a hollow polyolefin insulator containing a conductor, and an organic polymer jacket on top of the metal wire braided shield layer. A hollow polyolefin insulated wire, characterized in that the organic polymer layer is placed vertically on the hollow polyolefin insulator side, and the metal foil of the tape is electrically connected to the metal braided shield layer. (2) The hollow polyolefin according to claim 1, which uses an organic polymer constituting the organic polymer layer that has a static friction coefficient of 0.09 or more at room temperature with the polyolefin constituting the hollow polyolefin insulator. Insulated wire. (3) As a conductive metal foil tape, a hot melt tape has conductive metal foil on both sides of a polyester layer and an organic polymer layer provided on one of the conductive metal foils exhibits adhesive properties to the conductive metal foil. The hollow polyolefin insulated wire according to claim 1 or 2, using an adhesive.