JP2003141954A - Manufacturing method of straight-angle insulated wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a straight-angle insulated wire excellent in insulation property in which a uniform film is formed over a whole surface including corner parts after printing without fear of a conductive surface being exposed, without any large-scale change in the method of manufacturing the straight-angle insulated wire of applying and printing insulating varnish several times on the outer periphery face of straight-angle conductors. SOLUTION: A straight-angle insulating wire with excellent insulation property is manufactured through a rolling process f1 of rolling a cross-section circular round conductors into straight-angle conductors, a plasma treatment process f2 of improving wettability of a whole face or selectively corner parts of the conductors by putting the straight-angle conductors under plasma treatment, and varnish coating and printing process f3 of setting an insulating film of a given thickness by printing insulating varnish several times on the outside of the straight-angle conductors put under plasma treatment.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a rectangular insulated wire. More specifically, the voice coil of the speaker,
Small motor coil for video tape recorder (VTR), choke coil, linear voice coil for optical pickup,
The present invention relates to a method of manufacturing a rectangular insulated wire used for a motor coil for a floppy disk, a noise filter and the like.

[0002]

2. Description of the Related Art A method of manufacturing a flat insulated wire is a method of rolling a round conductor having a circular cross section into a flat conductor and applying an insulating paint to the outside by baking in accordance with a conventional method. The other is an insulating paint on the outside of the round conductor. There is a method of coating and baking and then rolling this to transform it into a rectangular insulated wire, but each method has the following drawbacks. That is, in the former method, when an insulating paint is applied to a rectangular conductor and baked, the fluidity of the paint increases as the temperature of the paint rises, and the film at the corners after baking becomes thin and a film of uniform thickness can be obtained. Have difficulty. If a rectangular insulated wire with a thin coating on the corners and a very exposed conductor surface is used in the coil winding of electrical equipment, it may cause insulation failure and significantly reduce the reliability of the equipment. On the other hand, in the latter method, a film having a uniform thickness can be obtained, but on the other hand, there is a problem of deterioration of characteristics due to work hardening of the conductor by rolling and work deterioration of the insulating film. The work-hardened conductor can be softened by heat treatment, but the work-deteriorated film has poor thermal shock resistance and cracking or peeling occurs. This phenomenon becomes more remarkable as the ratio of the thickness and width of the rectangular insulated wire increases, but especially when the ratio becomes a high rolling ratio of 1: 5 or more, innumerable cracks and peeling occur and the conductor surface is exposed, The insulation characteristics will be significantly reduced. Therefore, it cannot be applied to the coil.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve various problems of the above-mentioned prior art. The first conventional method is to apply an insulating coating material to the outer periphery of a rectangular conductor a plurality of times. Without making any major changes to the manufacturing method of the flat insulated wire to be baked, a uniform film is formed over the entire surface including the corner after baking, and the conductor surface is not exposed. It is an object to provide a method for manufacturing an electric wire.

[0004]

According to a first aspect of the present invention, there is provided a rolling step of rolling a round conductor having a circular cross section into a flat conductor, and a plasma treatment of the flat conductor.
A plasma treatment step for improving the wettability of the entire surface of the conductor or selectively the corner portion of the conductor; and coating of an insulating coating on the outside of the plasma-treated flat rectangular conductor a plurality of times to form an insulating coating of a predetermined coating thickness by baking. A baking step; and a method for producing a rectangular insulated wire having excellent insulation properties. In the method of manufacturing a flat rectangular insulated wire according to the first aspect, by performing plasma treatment on the flat rectangular conductor, the wettability of the entire flat rectangular conductor or selectively the corner portion of the conductor can be improved. As a result, it is possible to increase the affinity between the conductor corner portion and the insulating coating material, and the film forming property is imparted to the conductor corner portion. Therefore, by coating and baking an insulating paint on the outer periphery of a flat conductor that has been plasma-treated, an insulating coating is uniformly formed over the entire surface including the corners, and the conductor surface is not exposed and the flat conductor with excellent insulation properties is exposed. It becomes possible to manufacture an insulated wire.

As a second aspect, the present invention is a rolling step of rolling a round conductor having a circular cross section into a flat conductor; and applying an insulating coating to the outside of the flat conductor a plurality of times and baking it to obtain a predetermined coating thickness. Insulation coating coating A coating that improves the wettability of the entire conductor or selectively the corners of the conductor by plasma treatment of a rectangular conductor (hereinafter abbreviated as intermediate) on which a thin insulation coating is formed during baking. A coating and baking / plasma treatment step; and a method for producing a rectangular insulated wire having excellent insulation properties. Incidentally, the film thickness of the intermediate body to be plasma treated is preferably as thin as possible, for example, 0.
It is 001 mm to 0.005 mm. In the manufacturing method of the second aspect, the wettability of the entire flat conductor or the corners of the conductor can be improved by plasma-treating the intermediate body during coating and baking. As a result, it is possible to increase the affinity between the conductor corner portion and the insulating coating material, and the film forming property is imparted to the conductor corner portion. Therefore, by applying and baking insulating paint on the outer periphery of the plasma-treated intermediate, an insulating film is uniformly formed over the entire surface including the corners, and the conductor surface is not exposed, resulting in excellent insulation. It is possible to manufacture flat rectangular insulated wires.

As a third aspect, the present invention resides in a method for producing a flat insulated wire in which the flat conductor is copper, aluminum, or copper clad aluminum. In the manufacturing method of the third aspect, copper, aluminum, or copper clad aluminum can be preferably used as the rectangular conductor.

In a fourth aspect of the present invention, the insulating paint is a polyurethane insulating paint, a polyester insulating paint,
A method for producing a flat insulated wire, which is a polyesterimide insulating coating, a solderable polyesterimide insulating coating, a polyamideimide insulating coating, or a polyimide insulating coating. In the manufacturing method according to the fourth aspect, as the insulating paint, a polyurethane insulating paint, a polyester insulating paint, a polyesterimide insulating paint, a solderable polyesterimide insulating paint, a polyamideimide insulating paint, a polyimide insulating paint, or the like. Is mentioned. Specific examples of these insulating paints include polyurethane-based insulating paints.
WD4307-30% (Hitachi Chemical Co., Ltd. product name), polyester insulating paint LITON3300-30% (Totoku Paint Co., Ltd. product name), etc.

A fifth aspect of the present invention is a method for producing a rectangular insulated wire in which the wettability of the entire surface or corner portions of the plasma-treated rectangular conductor is 60 mN / m or more in terms of surface tension.
In the manufacturing method of the fifth aspect, since the wettability of the entire surface or the corner portion of the flat conductor after the plasma treatment is 60 mN / m or more in terms of surface tension, the wettability of the entire conductor surface or the conductor corner portion can be further improved. It is possible to increase the affinity between the conductor corners and the insulating coating material, and to sufficiently impart film forming properties to the conductor corners.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The contents of the present invention will be described below in more detail with reference to the embodiments shown in the drawings. The present invention is not limited to this. FIG. 1 is a chart showing one embodiment (Example 1) of the method for manufacturing a rectangular insulated wire of the present invention. FIG. 2 is a chart showing a second embodiment (Example 2) of the method for manufacturing a rectangular insulated wire of the present invention.

-First Embodiment (Example 1) -A method for manufacturing a rectangular insulated wire of Example 1 will be described with reference to the chart of FIG. First, round copper wire (φ0.70mm)
Was rolled to produce a rectangular copper wire with a conductor thickness of 0.30 mm and a conductor width of 1.30 mm (rolling process F1). Then, after annealing the rectangular copper wire, plasma treatment was performed on the entire surface of the rectangular copper wire using a plasma irradiator ST-7000 (product name manufactured by KEYENCE CORPORATION) (plasma treatment step F2). At this time, a sample of the rectangular copper wire subjected to the plasma treatment was taken and the surface tension was measured and found to be 70 mN / m or more. Next, a linear speed of 8 m / mi was applied so that the film thickness was 0.017 mm on the plasma-treated rectangular copper wire.
n, Using an electric heating baking furnace with a furnace temperature of 360 ° C, polyurethane insulation coating WD4307-30% (Hitachi Chemical Co., Ltd. product name) was applied and baked multiple times to produce rectangular insulated wires (paint application baking step F3).

-Second Embodiment (Example 2) -A method for manufacturing a rectangular insulated wire of Example 2 will be described with reference to the chart of FIG. First, round copper wire (φ0.70mm)
Was rolled to produce a rectangular copper wire having a conductor thickness of 0.30 mm and a conductor width of 1.30 mm. (Rolling process F1) Next, after annealing the above rectangular copper wire, the wire speed is 8 m / min and the furnace temperature is 360.
Polyurethane insulation paint WD4307
When coating and baking -30% multiple times, the film thickness on the rectangular copper wire is 0.
The 004 mm intermediate product (thin film rectangular conductor) is selectively plasma-treated at the corners of the intermediate product using the plasma irradiator ST-7000, and then applied multiple times to achieve a film thickness of 0.017 mm. Baking was performed to produce a rectangular insulated wire (paint coating baking / plasma treatment process F23). At this time, a sample of the intermediate product subjected to the plasma treatment was taken and the surface tension was measured and found to be 70 mN / m or more.

-Comparative Example 1-Rolled round copper wire (φ0.70 mm), conductor thickness 0.30 mm, conductor width
Using a 1.30 mm rectangular copper wire, after annealing, without applying plasma treatment, paint coating baking was performed under the same conditions as in Example 1 above.
A flat insulated wire was manufactured.

-Characteristics test-The rectangular insulated electric wires obtained in Examples 1 and 2 and Comparative Example 1 were subjected to a pinhole test and a dielectric breakdown voltage test (metal cylinder according to JIS C3003 enamel copper wire and enamel aluminum wire test method). Law). The results are shown in Table 1.

[0014]

[Table 1]

As is clear from Table 1 above, the rectangular insulated wire obtained by the method for producing a rectangular insulated wire of the present invention has excellent pinholes and dielectric breakdown voltage values as compared with the rectangular insulated wire of the comparative example. You can see that

[0016]

EFFECTS OF THE INVENTION According to the method for producing a rectangular insulated wire of the present invention, by rolling a round conductor into a rectangular conductor and then performing a pretreatment in which coating baking is performed a plurality of times, or a plasma treatment during coating baking, The wettability of the whole flat conductor or selectively the flat conductor corner is improved, and the affinity between the conductor corner and the paint is increased,
The film forming property is imparted to the corners. This makes it possible to form an insulating film uniformly over the entire surface including the corners.
It has become possible to obtain a flat insulated wire with excellent insulation without exposing the conductor surface. Therefore, the reliability of the coil wound by using the rectangular insulated electric wire obtained by the present invention is also greatly improved, which is very large in contributing to the industry.

[Brief description of drawings]

FIG. 1 is a chart showing one embodiment (Example 1) of the method for producing a rectangular insulated wire of the present invention.

FIG. 2 is a chart showing a second embodiment (Example 2) of the method for producing a rectangular insulated wire of the present invention.

Claims (5)

[Claims] 1. A rolling step of rolling a circular conductor having a circular cross section into a rectangular conductor; and a plasma treatment for improving the wettability of the entire conductor or selectively the corner portion of the conductor by plasma-treating the rectangular conductor. A step of applying and baking an insulating coating on the outside of the plasma-treated flat rectangular conductor a plurality of times to form an insulating coating having a predetermined coating thickness;
A method for producing a rectangular insulated wire, which comprises producing a rectangular insulated wire having excellent insulation properties. 2. A rolling step of rolling a circular conductor having a circular cross section into a rectangular conductor; and coating and baking an insulating coating having a predetermined coating thickness by coating and baking an insulating coating a plurality of times on the outside of the rectangular conductor. By applying a plasma treatment to a rectangular conductor (intermediate body) with a thin insulation film formed on it, coating and baking to improve the wettability of the entire conductor or selectively the corners of the conductor.
A method of manufacturing a flat insulated wire, which comprises producing a flat insulated wire having an excellent insulating property by a plasma treatment step. 3. The method for manufacturing a rectangular insulated electric wire according to claim 1, wherein the rectangular conductor is copper, aluminum, or copper clad aluminum. 4. The insulating paint is a polyurethane insulating paint, a polyester insulating paint, a polyesterimide insulating paint, a solderable polyesterimide insulating paint,
The method for producing a rectangular insulated wire according to claim 1, 2 or 3, which is a polyamide-imide insulating coating or a polyimide insulating coating. 5. The flat insulated wire according to claim 1, wherein the wettability of the whole surface or the corner portion of the plasma-treated flat conductor is 60 mN / m or more in terms of surface tension. Production method.