JP2003272455A - Surface treating method of covered wire and manufacturing method of covered wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treating method of a covered wire capable of improving wettability of an insulator layer and having a high productivity and manufacturing method of the covered wire. <P>SOLUTION: In the surface treating method of the covered wire 11A having the insulator layer around a conductor, an atmospheric plasma generator is used for the surface treatment. By doing so, the surface treatment of the covered wire made of an extruded insulator can be performed in a relatively easy and continuous manner. Especially, as plasma treatment can be efficiently applied to a thin covered wire by using a plasma treater for irradiating plasma from its nozzle, the surface treatment process can be incorporated in a manufacturing line of a conventional covered wire and the surface treatment can be conducted efficiently. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment method for a covered electric wire having an insulating layer formed of a fluorine resin material or the like and a method for manufacturing the covered electric wire. It is preferably used for cables with a sex shield.

[0002]

2. Description of the Related Art Generally, a covered electric wire is a conductor formed of a single wire or a multifilamentary wire having a predetermined diameter and an insulating layer applied to the surface of the electric wire. Fluororesin is used.

Further, such a covered electric wire is manufactured by continuously extruding an insulating layer on a conductor.
In order to identify the product at the time of use, characters or the like to be an identification mark are printed on the surface of the insulating layer at the time of manufacturing.

In making such marking, it has been attempted to print in a non-contact manner using an ink jet recording head. However, since the ink used in such an ink jet recording head is generally water-soluble, there is a problem that printing cannot be easily performed on an insulating layer made of a fluororesin material.

On the other hand, it has been proposed that the insulator layer is directly metal-plated to form a shield. For example, Japanese Patent Laid-Open No. 6-119824 discloses a metal-plated shield enameled wire in which a metal plating shield formed by electroless plating is provided on an enamel layer made of an ultraviolet curable resin provided on the outer periphery of a conductor. In addition, JP-A-2000-13
JP-A-2000-138014 discloses a coaxial cable in which an insulator made of fluorocarbon resin is provided on a conductor, a metal layer is formed on the insulator by electroless metal plating, and a metal layer is formed on the insulator by electrolytic plating. In the official gazette, an insulator made of fluororesin on a conductor and ABS coated on the insulator
A coaxial cable in which a resin coating layer, a metal layer provided on the coating layer by electroless metal plating, and a metal layer formed on the coating layer by electrolytic plating are further provided is disclosed.

However, none of them is intended to manufacture thin-line shielded cables with high productivity, their structure is complicated, and there is a problem in bending resistance of the shield. That is, there is a problem in that the adhesion between the insulating layer made of a fluororesin material and the metal plating layer is poor, and the shield is easily peeled off.

Therefore, in order to improve the adhesion when printing or plating, it is necessary to treat the surface of the insulating layer to improve the wettability.

[0008]

As described above, in order to roughen the surface of the insulator layer, physical surface treatment performed by irradiating fine particles, chemical surface treatment performed with acid or alkali, and the like are required. Although conceivable, all of them have a problem that they are not preferable as a method for continuously treating a coated electric wire coated with an insulating layer. Further, it is considered that printing by the inkjet printing means is performed in a high temperature environment, but there is a problem that high quality printing is difficult.

In view of such circumstances, it is an object of the present invention to provide a surface treatment method for a covered electric wire and a method for manufacturing a covered electric wire, which can improve the wettability of an insulating layer with high productivity.

[0010]

A first aspect of the present invention which solves the above-mentioned problems is a surface treatment method for a covered electric wire having an insulating layer around a conductor, the surface treatment using an atmospheric pressure plasma generator. The surface treatment method for a covered electric wire is characterized in that

In the first aspect, the wettability of the insulating layer is improved by continuously treating the coated electric wire coated with the insulating layer using the atmospheric pressure plasma generator.

A second aspect of the present invention is characterized in that, in the first aspect, the surface treatment is performed by irradiating a coated electric wire that is extrusion coated and conveyed with plasma from a nozzle of a plasma treater. There is a surface treatment method for the covered electric wire.

In the second aspect, the wettability of the insulating layer can be easily improved by irradiating the coated electric wire with the plasma from the nozzle of the plasma treater.

According to a third aspect of the present invention, in the second aspect, the plasma irradiation is performed from a direction inclined by 30 ° to 60 ° with respect to the conveying direction of the coated electric wire. Surface treatment method.

In the third aspect, the efficiency of the surface treatment of the insulator layer can be improved by inclining the plasma irradiation from the nozzle of the plasma treater by a predetermined angle with respect to the transport direction.

A fourth aspect of the present invention is the surface treatment method for a covered electric wire according to the second or third aspect, characterized in that the plasma irradiation is performed from a plurality of directions around the covered electric wire.

In the fourth aspect, the surface treatment can be efficiently performed by irradiating the plasma from a plurality of directions around the covered electric wire.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the surface of the covered electric wire is characterized in that after the surface treatment, the surface is covered with a solvent to be improved in wettability. It is in the processing method.

In the fifth aspect, after the surface treatment,
The deterioration of wettability due to aging can be suppressed.

A sixth aspect of the present invention is a method for producing a covered electric wire in which an insulating layer is provided around a conductor to form a covered electric wire, wherein an atmospheric pressure plasma generator is used for the covered electric wire which is extruded and conveyed. And a step of marking the surface of the surface-treated insulating layer with an inkjet printing means.

In the sixth aspect, the coated electric wire coated with the insulating layer is continuously treated by using the atmospheric pressure plasma generator to improve the wettability of the insulating layer and to mark by the ink jet printing means. Can be done with high quality.

A seventh aspect of the present invention is characterized in that, in the sixth aspect, the surface treatment is performed by irradiating a coated electric wire, which is extrusion-coated and conveyed, with plasma from a nozzle of a plasma treater. There is a method for manufacturing a covered electric wire.

In the seventh aspect, the wettability of the insulating layer can be easily improved by irradiating the coated electric wire with the plasma from the nozzle of the plasma treater.
In addition, marking with the inkjet printing means can be performed with high quality.

An eighth aspect of the present invention is the coated electric wire according to the seventh aspect, wherein the plasma irradiation is performed from a direction inclined by 30 ° to 60 ° with respect to the conveying direction of the coated electric wire. In the manufacturing method.

In the eighth aspect, the efficiency of the surface treatment of the insulator layer can be improved by inclining the irradiation of plasma from the nozzle of the plasma treater by a predetermined angle with respect to the transport direction.

According to the present invention, since the insulator layer of the covered electric wire is treated using the atmospheric pressure plasma generator, the covered electric wire extruded with the insulator layer can be surface-treated relatively easily and continuously. Can be given. In particular, by using a plasma treater that irradiates plasma with a nozzle, it is possible to efficiently perform plasma treatment even on thin coated electric wires, so it is easy to incorporate the surface treatment process into the conventional coated electric wire production line and efficiently Surface treatment can be performed. The processing gas for generating plasma is not particularly limited and may be air, but other processing gas such as helium may be used as appropriate.

Here, when the plasma is irradiated from the nozzle to perform the surface treatment, it is preferable to irradiate the covered electric wire from a direction inclined by 30 ° to 60 °. This is for efficient surface treatment. Therefore, even if it deviates from this range, the surface treatment can be performed although the efficiency is lowered. The irradiation direction is not particularly limited, such as the front or rear of the transport direction, and the advantageous direction differs depending on the material. Therefore, it is preferable to appropriately select the advantageous direction depending on the material.

Further, when the plasma is irradiated from the nozzle in this way to surface-treat the entire periphery of the covered electric wire, it is preferable to irradiate the plasma from a plurality of directions around the covered electric wire. Moreover, when irradiating from a plurality of surrounding directions, it is preferable to irradiate at different positions along the transport direction. This is for efficient surface treatment. By surface-treating the entire covered electric wire in this manner, it is possible to improve the adhesion to the plating layer provided on the outer periphery of the electric wire and the printing.

However, in the case of marking continuously,
Since it is sufficient to perform the surface treatment only on the surface in at least one circumferential direction, in this case, the plasma treatment may be performed from one direction. Furthermore, in order to increase the efficiency of plasma processing, a plurality of plasma treaters may be provided in the transport direction to perform plasma processing.

Here, the plasma irradiation conditions by the plasma treater are not particularly limited, and the irradiation may be performed under the condition that the surface treatment can be performed. That is, the irradiation may be performed under the condition that the irradiated plasma efficiently contacts the coated electric wire, and the material of the insulating layer and the extent to which the surface modification is performed may be appropriately examined.

As described above, the wettability after the surface treatment by the method of the present invention is about 80 degrees or less, although it varies depending on the diameter when measured by the contact angle with distilled water.

After performing the surface treatment of the present invention, it is preferable to immerse it in a solvent whose wettability is desired to be improved, for example, water. This makes it possible to prevent deterioration of wettability due to aging.

Here, the conductive wire included in the coated electric wire of the present invention is a single wire having a predetermined diameter, for example, a diameter of 30 μm.
A wire of about 0.8 mm may be used alone,
A multifilamentary wire, for example, a collection of a plurality of ultrafine wires having a diameter of about 10 to 120 μm may be used.

The structure of the covered electric wire in which the insulating layer is applied around the conductor may be a single wire covered with the insulating layer or a multi-core wire covered with the insulating layer.
The coaxial line structure may have a structure in which a conductor is provided on the insulator layer provided around the central conductor and further an insulator layer is provided.

In the present invention, the conductor may be, for example, an electric soft copper, an electric hard copper, a tin-containing copper alloy, a chromium-zirconium-containing copper alloy or an in-situ fiber-reinforced copper alloy. A conductor made of an in-situ fiber-reinforced copper alloy is preferable in terms of bending resistance.

Here, the in-situ fiber-reinforced copper alloy wire is a fiber-reinforced copper matrix, in particular:
It refers to a wire formed by forming fibers on the spot, that is, in the step of forming the wire. For example, it refers to a wire or the like containing in-situ formed fibrous chromium having a maximum diameter of 2.5 μm or less and an average diameter of 1.0 μm or less in a copper matrix.

The conductor made of such an in-situ fiber-reinforced copper alloy is obtained by, for example, swaging an alloy material having a chromium content of 1 to 25% by weight and a balance of substantially copper, followed by the first step. Cold drawing, then solution treatment, and then second cold drawing to form a fibrous chrome in situ in a copper matrix to obtain a wire. It is obtained by forming a conductive wire using at least one piece. The alloy material used as the material is not limited to those described above, and for example, the chromium content is 1 to 25% by weight, the silver or zirconium content is 0.01 to 8% by weight, and the balance is substantially the same. An alloy material made of copper can also be used.

In the wire rod made of such a composite material, high conductivity can be ensured by the flow of electric current in the copper matrix, and mechanical strength can be secured by fiber reinforcement, and characteristics of high mechanical strength and high conductivity are obtained. Also has.

Examples of the insulating layer of the covered electric wire of the present invention include polyester resins, fluorine resins, polystyrene resins, polyolefin resins, etc. for coaxial cables. However, a fluororesin or polyethylene is preferable, and a fluororesin is most preferable from the viewpoint of low dielectric constant, favorable for diameter reduction, and bending resistance.

As the fluorine-based resin, ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene perfluoroalkoxyethylene copolymer (P
FA), fluoroethylene hexafluoropropylene copolymer (FEP) and the like.

The method of forming an insulating layer on a conductor to produce a covered electric wire is not particularly limited, and, for example, the step of producing a conductor and the step of producing an insulator layer may be carried out continuously or separately. Although it may be a step, it is preferable that after the coating step, a surface treatment step is continuously performed, and further marking by an inkjet printing means is performed.

The ink jet printing means is not particularly limited as long as it prints by ejecting ink droplets on the surface of the covered electric wire, and the type of ink is not particularly limited such as water-soluble ink and oil-soluble ink.

The covered electric wire of the present invention may be used as a shielded cable by forming a shield on, for example, a plurality of twisted pieces, or after providing an insulating layer on a plurality of twisted pieces. Alternatively, a shielded cable provided with a sheath may be used.

In addition, since the coated electric wire of the present invention has improved wettability of the insulating layer, the metal plating layer can be easily formed thereon. That is, for example, 0.5 μ
Forming a metal plating layer having a thickness of m to 6 μm has the advantage that a shield that sufficiently functions as a shield and does not pose a problem in terms of bending resistance is obtained, and that peeling is difficult.
Note that such a metal plating layer may be formed only by electroless plating, or electroless plating and electroplating may be combined. Alternatively, it may be formed by a dry method such as sputtering, CVD, or vacuum evaporation. Examples of the metal plating layer include copper, silver, nickel, gold, etc., or composite plating or alloy plating of these.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the surface treatment method and the method for producing a covered electric wire according to the present invention will be described with reference to Examples.

FIG. 1 shows a sectional structure of a covered electric wire manufactured in this embodiment. The covered electric wire 1 shown in FIG. 1 is a single wire conductor 2 provided with an insulating layer 3. That is, the covered electric wire 1 is a conductor 2 made of an in-situ chromium fiber reinforced copper alloy (chromium content of about 10%) and an insulator layer 3 made of a fluororesin provided on the conductor 2.

FIG. 2 shows a schematic structure showing a manufacturing process of such a covered electric wire 1. As shown in FIG. 2, on the conductor 11 sent from a not-shown feeder, the insulating layer 3 is formed by the extruder 12 to form the covered electric wire 11A, and then the first cooling tank 13 and the take-up machine 14 are provided. , Horizontal guide 15, vertical guide 16
And is guided to the second cooling tank 17 via the horizontal guide 18, the vertical guide 19, and the take-up machine 20.
To be wound up.

In the present embodiment, the plasma treater 31 is arranged immediately before the first cooling tank 13 and the second cooling tank 17 is provided.
The rotary encoder 32 and the inkjet print head 33 are arranged in front of.

According to this, the covered electric wire 11A is surface-treated by the plasma of the plasma treater 31, and thereafter, marking is performed by the ink jet print head 33 at each predetermined position measured by the rotary encoder 32.

Here, the position where the plasma treater 31 is arranged is not particularly limited, and may be provided at least on the upstream side of the ink jet print head 33. For example, as shown in FIG. You may arrange | position between the machine 14 and it.

Further, the irradiation direction of the plasma from the plasma treater 31 is, as shown in a test example described later, from a direction inclined by 30 ° to 60 ° with respect to the conveying direction of the covered electric wire 11A, and from the rear side toward the conveying direction. It is preferable to irradiate. That is, as shown in FIG. 4A, the angle θ between the transport direction and the plasma treater 31 is 30 ° to 60 °.
It is preferably °.

Further, only one plasma treater 31 may be provided, but two or three or more plasma treaters 31 may be provided. As shown in FIG. 4B, a plurality of plasma treaters 31 may be provided in the transport direction. , For example, two plasma treaters 31
A and 31B may be arranged. Provide a plurality of insulated wires 1
In the case of surface-treating the entire circumferential direction of 1A, FIG.
As shown in FIG. 3, the plasma treaters 31A and 31A are configured to irradiate different positions to different positions along the transport direction.
It is preferable to arrange B.

On the other hand, the arrangement of the ink jet print head 33 is not particularly limited as long as it can be dried for at least 1 second after printing. For example, as shown in FIG. 5, a rotary encoder is provided after the second cooling tank 17. 32
The inkjet print head 33 may be disposed between the horizontal guide 18 and the vertical guide 19.

(Example 1) Materials for the insulating layer were PFA (Example 1a), FEP (Example 1b), ETFE (Example 1c), PTFE (Example 1d) and polyethylene (Example 1e). A coated electric wire having an outer diameter of about 1 mm was subjected to a surface treatment with an apparatus configuration as shown in FIG. However, although the plasma treater 31 is inclined by 60 ° with respect to the carrying direction, it is arranged so as to irradiate the plasma from the direction opposite to the carrying direction, contrary to FIG. 2, and the output is 490 V, 16 A, and the nozzle tip is The distance from to the covered electric wire was about 4 mm.

Contact angle after surface treatment (advancing angle and receding angle)
Was measured by a contact angle measuring device according to the meniscus method, and the difference between the right angle and the right angle was also shown in Table 1. In addition, Table 2 shows the contact angles before the surface treatment.

From these results, although the effect of the surface treatment varies depending on the material of the insulating layer, the wettability is improved by the surface treatment, and the wettability is remarkably improved by the irradiation at 60 ° rather than the right angle irradiation. there were.

The output of the plasma treater 31 is set to 4
The same operation was carried out at 11 A at 30 V and 8.5 A at 377 V, but almost the same surface treatment effect was observed.

[0058]

[Table 1]

[0059]

[Table 2]

(Example 2) PFA (Example 2a), FEP (Example 2b), ETFE (Example 2c), and PTFE (Example 2d) were used as the material of the insulating layer, and the outer diameter was about 1 mm.
The coated electric wire of 1 was subjected to a surface treatment with the apparatus configuration shown in FIG. In addition, the same procedure as in Example 1 was performed except that the plasma treater 31 was inclined at 45 ° with respect to the transport direction.

Contact angle after surface treatment (advancing angle and receding angle)
Was measured with a contact angle measuring device according to the meniscus method, and the difference between the right angle and the 45 ° is also shown in Table 3.

From these results, although the effect of the surface treatment varies depending on the material of the insulating layer, the wettability is improved by the surface treatment, and the wettability is more significantly improved by the 45 ° irradiation than by the right angle irradiation. there were.

[0063]

[Table 3]

(Embodiment 3) As shown in FIG. 2, the plasma irradiating direction of the plasma treater 31 is the same as the carrying direction (positive direction), and the inclination angle with respect to the carrying direction is 4 degrees.
The insulator layer was FEP (Example 3b) and ETFE in the same manner as in Example 1 except that the angle was 5 ° (θ = 45 ° in FIG. 4).
The coated electric wire of (Example 3c) having an outer diameter of about 1 mm was subjected to a surface treatment with an apparatus configuration as shown in FIG.

The results are shown in Table 4 in comparison with the results in the opposite direction (Example 2).

From these results, it was found that when the insulating layer was FEP, the reverse direction was more effective, but when ETFE was used, the positive direction was more advantageous. .

[0067]

[Table 4]

(Example 4) A coated electric wire having an outer diameter of about 1 mm, which was ETFE (Example 4c), was subjected to a surface treatment with a plasma treater inclined at 45 ° from the positive direction as in Example 3, and then air-treated. Table 5 shows the results of measuring the contact angles of the samples after one day of standing in the medium and one day after leaving in the water.

As a result, it was found that the effect of the surface treatment on the insulator layer made of ETFE is reduced with time by leaving it in the air, but the change with time can be reduced by storing it in water. When an insulator layer made of FEP or PFA was used, the change with time was not remarkable.

[0070]

[Table 5]

(Examples 5 to 7) Plasma treater 31
A coated electric wire having the same structure as that shown in FIG. 2 was manufactured except that the electric wires were provided at two positions sandwiching the covered electric wire. The plasma treater 31 was placed at a position opposed to each other with a shift of 5 cm in the carrying direction and inclined by 60 ° from the carrying direction.

Transport speed of the covered electric wire is 3.5 m / min
(Example 5), 10.5 m / min (Example 6), 40
The durability of the marking printed by the inkjet print head 33 was tested at m / min (Example 7).

In the friction test, as a result of rubbing the markings with the finger pad 10 times, the mark in which the printing was not erased was evaluated as ◯, the mark in which the printing was partially erased was evaluated as Δ, and the mark which was completely erased was evaluated as x. In the peel test, the cellophane tape was strongly adhered to the print with the finger pad, and the film was instantaneously peeled off in 45 ° direction from the adhered surface. Things are △, all things are moved ×
Evaluated as.

For comparison, the same evaluation was carried out for the case where the coated electric wire was not surface-treated but was marked with the ink jet print head immediately after extrusion (the temperature of the covered electric wire was 230 ° C.) (Comparative Example). The conveyance speed of the covered electric wire in the comparative example was 50 m / min.

The results are shown in Table 6. From this result,
Example 5 in which the surface treatment by plasma irradiation was applied, as compared with the comparative example in which the coated electric wire was marked at high temperature
It was found that marking durability of 7 to 7 was better.

[0076]

[Table 6]

[0077]

As described above, since the surface treatment is performed by using the atmospheric pressure plasma generator, the wettability of the insulator layer can be improved with high productivity.

[Brief description of drawings]

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

FIG. 2 is a diagram schematically showing a manufacturing process of a covered electric wire according to an embodiment of the present invention.

FIG. 3 is a diagram showing an outline of a manufacturing process of a covered electric wire according to another embodiment of the present invention.

FIG. 4 is a diagram showing an arrangement example of a plasma treater of the present invention.

FIG. 5 is a diagram schematically showing a manufacturing process of a covered electric wire according to another embodiment of the present invention.

[Explanation of symbols]

1 covered electric wire 2 conductors 3 Insulator layer 11 conductors 11A covered electric wire 31 Plasma Treater 33 inkjet print head

Claims (8)

[Claims] 1. A surface treatment method for a coated electric wire having an insulator layer around a conductor, wherein the surface treatment is performed using an atmospheric pressure plasma generator. 2. The surface treatment method for a coated electric wire according to claim 1, wherein the surface treatment is performed by irradiating a coated electric wire that is extrusion-coated and conveyed with plasma from a nozzle of a plasma treater. 3. The surface treatment method for a covered electric wire according to claim 2, wherein the irradiation of the plasma is performed from a direction inclined by 30 ° to 60 ° with respect to a conveying direction of the covered electric wire. 4. The surface treatment method for a covered electric wire according to claim 2, wherein the plasma irradiation is performed from a plurality of directions around the covered electric wire. 5. The surface treatment method for a covered electric wire according to claim 1, wherein the surface treatment is followed by immersion in a solvent that is an object for improving wettability. 6. A method of manufacturing a covered electric wire, wherein an insulating layer is provided around a conductor to form a covered electric wire, and a step of subjecting the covered electric wire that is extrusion-coated and conveyed to a surface treatment using an atmospheric pressure plasma generator, And a step of marking the surface-treated insulating layer surface with an inkjet printing means. 7. The method for producing a coated electric wire according to claim 6, wherein the surface treatment is performed by irradiating a coated electric wire that is extrusion-coated and conveyed with plasma from a nozzle of a plasma treater. 8. The method for manufacturing a covered electric wire according to claim 7, wherein the irradiation of the plasma is performed from a direction inclined by 30 ° to 60 ° with respect to a conveying direction of the covered electric wire.