JPH07111110A - Flat multi-core shielded electric wire and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Object] The present invention aims to obtain a flat multicore shielded wire in which the number of cores can be easily changed, the physical and electrical characteristics are stable, and the terminal processing is easy. To aim. [Structure] A jacket layer of a shielded wire core is formed by using a resin composition mainly composed of a thermoplastic polymer having a -CO bond in its molecular structure and having a melt flow rate of 10 g / 10 min or more. It is characterized by Then, the flat core multi-core shielded electric wire is obtained by manufacturing and storing the shield core in a state of being manufactured and fusing arbitrary numbers of cores to each other as necessary. More preferably, the flat core multi-core shielded electric wire can be obtained by irradiating radiation in the state of the shield core to cross-link the jacket layer made of the resin composition and then fusing the shield cores to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field of information communication, and more particularly to a flat type multi-core shielded wire used for wiring between computers such as computers, digital electronic exchanges, various measuring instruments, and in-machine wiring.

[0002]

2. Description of the Related Art For the above-mentioned applications, a flat type multi-core shielded wire in which a number of shielded wire cores are arranged in parallel has been used because of a sparse factor. Then, as a manufacturing method thereof, a method of providing a batch outer coating on a plurality of shield cores by extrusion, a method of applying a solvent between adjacent cores, a method of pressing adjacent cores while heating them at high temperature, and fusing each other, etc. It is used.

[0003]

In the case of the method of providing the collective outer coating by extrusion, the number of cores determined in advance is good, but it is not easy to change the number of cores, and the number of cores is appropriately changed. It cannot be done economically and efficiently. On the other hand, while applying a solvent between the adjacent cores or heating them to a high temperature, the method of pressing the adjacent cores to fuse them to each other is to vary the strength of the fused parts or to receive heat and pressure during fusion. In some cases, the insulator is deformed or the shape of the shield core is deformed, the dimensional accuracy between the central conductors cannot be obtained, and a problem occurs in the electrical characteristics. Also, in any of the methods, it is difficult to integrate the jacket layer and the shield layer of the shielded wire core. If it is not integrated, there is a problem that it will take time to process the terminal, but in order to integrate it, another device such as providing an adhesive layer with the jacket layer outside the shield layer is required, which is not economical. .

[0004]

Means for Solving the Problems The present invention has solved the above-mentioned problems and is capable of easily changing the number of cores, has stable physical and electrical characteristics, and is easy to machine into a flat type. An object is to provide a core shielded electric wire. Specifically, it is a resin composition mainly composed of a thermoplastic polymer having a —CO bond in its molecular structure, and has a melt flow rate (MFR, J
It is characterized in that the shielded wire core is formed using a resin composition having an ISK6760) of 10 g / 10 min or more.

Then, the shield core is manufactured and stored, and any number of cores are fused to each other as necessary. More preferably, the shield core may be fused with each other after the jacket layer made of the resin composition is crosslinked by irradiation with radiation in the state of the shield core.

[0006]

Example A foamed layer made of a resin composition composed mainly of polyethylene was provided on a silver-plated copper alloy wire having an outer diameter of 0.18 mmφ to produce an insulated wire having an outer diameter of 0.7 mmφ. While a silver-plated copper alloy wire having an outer diameter of 0.203 mmφ was vertically attached to the foamed electric wire as a drain wire, a 15 μm thick copper-deposited aluminum-attached polyester tape was wrapped to form a shield layer. Subsequently, each of the resin compositions A and B shown in Table 1 was extrusion-coated to form a jacket layer, and as shown in FIG. 1, a rectangular shield wire core having a length of 1.20 mm and a width of 1.27 mm was prepared. . (They are referred to as the rectangular shield core A1 and the rectangular shield core B1, respectively.)

Further, a 15 μm-thick copper-deposited aluminum-attached polyester tape having a thickness of 13 μm is directly lapped on the foamed electric wire to form a shield layer, and a 0.203 mmφ silver-plated copper alloy wire is vertically attached as a drain wire. Table 1
The resin compositions A and B of 1. are extrusion-coated to form jacket layers, and as shown in FIG.
A 27 mm square shield core was created. (They are referred to as square shield core A2 and square shield core B2, respectively.)

[0008]

[Table 1]

As a comparative example, only the material of the jacket layer was changed to the composition C of Table 1, and similarly, a rectangular shield core C1 provided with a drain wire inside the shield layer and a drain wire outside the shield layer. And a square shield core C2 provided with.

Square shield cores A1, A2, B1, B
Attempts were made to arrange 10 cores of each of 2, C1 and C2 into a flat shape, and heat-bond each to a ribbon shape as shown in FIG. A
1, A2, B1 and B2 could be relatively easily heat-fused by only heating the hot plate at 150 ° C. for about 2 minutes. As a result, a flat type multi-core shielded electric wire with stable characteristic impedance and capacitance was obtained. On the other hand, C1,
C2 does not adhere well under the same conditions as above, and the temperature is 180
By raising the temperature to ℃ and applying a load of 1 Kg / cm ² , fusion could be finally achieved. However, as a result, the jacket layer was also deformed, and the foaming of the insulator in the fusion-bonded portion was also crushed, resulting in an electric wire with a large variation in the characteristic impedance and electrostatic capacitance in the length direction.

Next, the rectangular shield cores A1, A2, B
1, B2, C1, C2 were respectively irradiated with radiation to cross-link the respective jacket layers, and then 10 cores were arranged in a flat shape in the same manner as described above and heat-sealed. A1, A
Similar to the above, 2, B1 and B2 could be easily heat-sealed, and the shape of the rectangular shield core was hardly changed by heat-sealing, so that the pitch between conductors could be easily controlled and the characteristic impedance A flat type multi-core shielded electric wire with a good control of 75 ± 5Ω was obtained.
When the jacket layer is cross-linked with C1 and C2, heat fusion is more difficult than in the case where the jacket layer is not cross-linked, and the shape of the jacket layer does not change much due to heat fusion, but the foaming of the insulation at the fusion portion is crushed. There was a problem of being lost. As a result, the electric wire has a large variation in the capacitance in the length direction.

[0012]

One of the features of the present invention is a resin composition mainly composed of a thermoplastic polymer having a —CO bond in its molecular structure as a material for the jacket layer, and having a melt flow rate of 10 g / 10 min or more. To use a resin composition. As the thermoplastic polymer having a —CO bond in the molecular structure, ethylene vinyl acetate copolymer, ethylene ethyl acrylate or the like can be used, but silicon graft ethylene ethyl acrylate is particularly effective for the purpose of the present invention. In the present invention, a resin composition obtained by adding a flame retardant or the like to these polymers has a melt flow rate of 10
Although it is necessary to form the jacket layer with a composition of g / 10 min or more, the first effect obtained by using the composition such as the resin composition A or the resin composition B for the jacket layer is a rectangular shielded wire core. That is, it is very easy to heat-bond each other. Therefore, it can be manufactured and stored as a rectangular shielded wire core, and a flat multi-core shielded electric wire having a required number of cores can be obtained as necessary. Further, this heat fusion is easy, and it is possible to obtain a flat type multi-core shielded electric wire which has little influence on the insulator because it does not need to be pressurized and only has to be lightly heated and has stable electric characteristics.

Another advantage of using the composition of the present invention, such as the resin composition A and the resin composition B, for the jacket layer is that the shield layer and the jacket layer can be easily integrated, and as a result, terminal processing can be performed. Can be done easily. When the shield layer and the jacket layer are integrated, the jacket layer and the shield layer can be formed by peeling once for the terminal treatment at the ends where the 10 cores are arranged in a plane and heat-bonded to each other in a ribbon shape. And can be removed all at once. On the other hand, for example, when the resin composition C is used for the jacket layer, the shield layer and the jacket layer are not integrated, so that the jacket layer is removed once in the terminal treatment, and then the shield layers are removed one by one. It is necessary and very time-consuming.

When the resin composition of the present invention is used for the jacket layer, the jacket layer and the shield layer can be easily integrated because the composition is fused to both plastic and metal. This is because it has easy characteristics.Even in the structure in which the drain wire is vertically attached to the insulator, the metal surface is on the inside and the copper taped aluminum-clad polyester tape is wrapped to form the shield layer, the metal surface is on the outside. Wrapping, and drain wire is vertically attached to this, either structure, when extruding the jacket layer,
The feature is that the jacket layer and the shield layer can be easily integrated.

Another feature of the present invention is that the rectangular shield wire cores are irradiated and crosslinked by radiation and then heat-sealed to each other. When the jacket layer is cross-linked, the shape does not change at all even if some heat is applied, so it is easy to control the pitch accuracy between conductors, and thus a ribbon-shaped flat multi-core shielded wire with stable impedance can be obtained. To be

[Brief description of drawings]

FIG. 1 shows an example of a cross section of a rectangular shielded wire core according to the present invention.

FIG. 2 shows another example of a cross section of a rectangular shielded wire core according to the present invention.

FIG. 3 shows an example of a cross section of a flat type multi-core shielded electric wire in which rectangular shielded wire cores according to the present invention are arranged in a plane and heat-sealed to each other.

[Explanation of symbols]

 1: Conductor 2: Insulator 3: Shield layer 4: Drain wire 5: Jacket layer

Claims (3)

[Claims] 1. A shield wire core jacket layer is a resin composition mainly composed of a thermoplastic polymer having a —CO bond in its molecular structure, and its melt flow rate (MFR, JI).
SK6760) is a resin composition of 10 g / 10 min or more, and is a flat type multi-core shielded electric wire. 2. The flat multicore shielded electric wire according to claim 1, wherein the jacket layer and the shield layer of the shielded wire core are integrated. 3. The jacket layer of the shielded wire core is made of the resin composition according to claim 1, the shielded wire core is irradiated with radiation to crosslink the jacket layer, and then a plurality of the flattened layers are arranged in a plane. And at least one end thereof is heat-sealed. Manufacturing method of flat type multi-core shielded electric wire.