JPS6337923B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing a winding wire with excellent quality and performance, and in particular, a method for producing a fresh copper surface by removing defects such as scratches formed on the surface of the copper wire. After that, a desired insulating paint is applied and baked to manufacture the winding wire.

Insulated wires, which are generally obtained by coating copper wires with various insulating paints such as urethane paints, polyamide paints, formal paints, polyimide paints, polyimide amide paints, etc. and baking them, are used in large quantities as electromagnetic coil windings.

Since this winding exhibits a high degree of insulation with a coating as thin as possible, it is most important that the coating be uniform and defect-free.

A necessary condition for this is that the surface integrity of the copper wire, which serves as a conductor, is strongly required. In other words, copper wire has lubricating oil and copper powder on its surface that are generated during the wire drawing process, and this has a major adverse effect on the integrity of the wire.
Furthermore, essentially serious inhibiting factors are those formed by cracks on the copper wire surface and the intrusion of foreign substances such as scale during processing processes such as casting, hot rolling, and wire drawing. The harmful effects of micro-cracks and their resulting fractures are self-evident if the thickness of the insulating coating is usually between 5 and 50 microns or less. Even if the surface of the copper wire is peeled using a peeling die or the like during wire drawing, scratches will be generated on the soft surface of the copper wire due to contact with various tools in subsequent steps. Furthermore, it is extremely difficult to make the surface of the copper wire defect-free because new defects may occur in the leather wire itself due to wear and tear on the die.
For this reason, it was necessary to increase the number of times the insulating paint was applied to thicken the coating film in order to ensure the insulation properties.

There is also a method of cleaning the copper wire with an organic solvent or an alkaline aqueous solution to remove the adhering substances such as the oil or metal powder, but these cleaning methods are effective to some extent in removing the adhering substances. Nothing could be done to remove the defective parts.

The present invention has been made in view of the current situation, and as a result of intensive research, we have discovered a method for manufacturing a winding wire with excellent performance by removing defective parts on the surface of the copper wire through a simple process and using a normal insulating paint coating and baking process. It is. That is, the method of the present invention includes a first step of electrolytically dissolving a copper wire using it as an anode, a second step of performing electrodeposition using the copper wire as a cathode, and drawing the electrodeposited copper wire using at least one die. and a fourth step of using the drawn copper wire as a conductor and applying and baking an insulating paint on the outside thereof.

In the method of the present invention, before carrying out the conventional insulating paint coating and baking process, the copper wire is first electrolytically dissolved and then electrodeposited on the copper wire in a copper electrolyte. When current is applied in an electrolytic solution, particularly an acidic solution such as sulfuric acid, phosphoric acid, boronic acid, or sulfamic acid, or a complex bath such as ammonia or alkali cyanide, with the wire side as the anode and the counter electrode as the cathode, the current is 100 A/dm ² according to Faraday's law. The maximum current density is 0.36μ/sec (in a monovalent cyanide bath)
0.73μ/sec), and the eluted copper is deposited on the cathode side. In this case, the current density that can be used depends on the external temperature of the bath composition, the number of times of stirring, the linear speed, etc., but it is 10 to 100 A/dm ² for the above-mentioned acidic bath, and 5 to 50 A/dm ² for the complex bath.

The second step of the method of the present invention is carried out in a copper electrolyte using the copper wire as the cathode and the counter electrode as the anode.
Since the copper ions in the liquid are deposited on a line, the copper lost in the first step can be recovered and a fresh copper surface can be formed. As the copper electrolyte, the above-mentioned acidic solution or complex bath in which copper is appropriately dissolved is used. In this case, insufficient copper content limits the current density, while excessive copper content may cause anode passivation, so it must be set appropriately depending on the type of bath and other conditions. Further, when copper is used as the counter anode, it is convenient because the copper in the liquid that is consumed can be constantly replenished. The precipitated copper can be made into dense crystals by changing the bath composition conditions, especially by adding a small amount of additives. The speed of electrodeposition follows Faraday's law like the above-mentioned bathing, so it can be set arbitrarily based on the current density.

In the method of the present invention, when the dissolution in the first step and the precipitation in the second step are the same, the treatment may be continued without washing with water in the middle, and the precipitation may be followed by washing with water and drying. The processing time, processing amount, and current value of the above-mentioned processing are determined by the line speed and the desired amount of dissolution and precipitation, and often require a plurality of tanks.

As an example of the method of the present invention, a case is explained in which one electrolytic bath and one electrodeposition bath are provided for processing. a is a copper wire, 1 is a dissolution bath, 2 is a precipitation bath, and the electrodes 11 and 2 are a precipitation bath, respectively. Holds 12. 13,14
is a contact for supplying power to copper wire a,
Each is connected to the positive and negative terminals of the DC power supply. First, the electrolyte described above is used.

As is clear from Figure 1, a power supply roll is used with two power supplies, which not only complicates the equipment, but also causes mechanical wear, friction scratches, and electrical damage such as sparks when tangent to the rolls. There is a high risk of disturbing the surface. On the other hand, if the opposite electrodes of the two tanks are connected to the negative and positive power supplies, respectively, as shown in FIG. 2, power can be supplied without contact without using a power supply roll. This method is most suitable when dissolution and precipitation are performed in pairs as in the method of the present invention. Alternatively, as shown in FIG. 3, one tank may be partitioned into two, and a shielding plate 15 is provided in the middle of the tank to suppress direct current flowing between the counter electrodes (not via a wire). However, in the method shown in Figure 2, the liquid properties between the two tanks can be arbitrarily selected, whereas in the method shown in Figure 3, the liquid is limited to the same liquid, or in any case, it can be processed without contact. Therefore, it is advantageous because the equipment can be simplified and the occurrence of defective parts due to contact power supply can be completely eliminated.

Regarding the maintenance of the counter electrode in the above method, copper is deposited on the counter electrode 11 of the dissolution tank, so it must be renewed after a certain period of time, whereas the counter electrode of the precipitation tank acts as an anode, so there is no need to replace the anode, which is consumed by dissolution. I have to replenish. Needless to say, the amounts of copper counter electrodes in both tanks can be substantially balanced.

In this way, the amount of dissolved copper or the amount of precipitated copper in the treatment according to the method of the present invention must be determined primarily by the quality of the copper wire to be treated, and usually
Sufficient effects can be achieved at 0.05μ or more, especially around 0.1 to 3μ.

In addition, defects on the copper wire surface can reach a depth of several microns to several tens of microns in some cases.
In precipitation, the surface layer of the copper wire is thinly dissolved during the melting process of the first step, removing small defects and at the same time, various foreign substances adsorbed on the surface or contained within the cracks are peeled off, resulting in complete cleaning. . Then the second
In order to firmly coat the surface of the copper wire with fresh copper during the precipitation process to form a healthy and uniform surface layer,
It is possible to provide a copper wire surface suitable for drawing the wire in the third step and applying and baking an insulating paint in the fourth step. That is, in the first and second steps, minute irregularities occur on the surface of the copper wire, resulting in a decrease in smoothness and gloss.Since this affects the appearance gloss after the insulation paint is applied and baked, the die is removed in the third step. The wire is drawn by the method, and the wire is passed through at least one die to achieve a reduction in area of about 1 to 5%.The so-called skin pass wire drawing exhibits a sufficient effect. It is also possible to subject an intermediate-sized copper wire to the above-described melting and precipitation treatments and then draw it continuously. Furthermore, since the surface condition of intermediate-sized copper wires can be improved, the quality of fine wires on the upstream side can also be improved.

In this way, the method of the present invention includes dissolution in the first step, dissolution in the second step,
Precipitation in the step, wire drawing in the third step, and coating and baking in the fourth step can be performed continuously in one line in a heat treatment furnace before coating if necessary, which improves productivity and prevents damage. There is no risk of this occurring.

Next, examples of the present invention will be described.

Example 1 Neomar paint was applied to the outside of a 0.44φ copper wire (O material) at 60 m/min at 380°C and baked to increase the film thickness.
In manufacturing 18μ winding wire, before coating the copper wire with the Neomar, the copper content is 40g/free sulfuric acid.
A vinyl chloride partition plate having a passage hole for the line is provided in the center along the longitudinal direction of a 5 m long tank in which a sulfuric acid copper sulfate bath containing 40 g/sulfuric acid is sprayed and circulated. Let it pass through the processing tank. In addition, a copper plate was placed in the first tank and the second tank, respectively.
The copper plate in the first tank was connected to a DC power source, and the copper plate in the second tank was connected to a DC power source, and a current of 6.0 A was applied at a bath temperature of 45°C.

Next, after passing through the treatment tank, the wire was sprayed with clean water, washed, dried in hot water, and then passed through a 0.43φ diamond die using gasoline as a lubricant to draw the wire. The winding wire of the present invention was obtained by coating and baking.

After the winding thus obtained was left in a constant temperature bath at 95% relative humidity and 60° C. for one week, a twisting test was performed to determine the presence or absence of peeling of the insulation coating, but no peeling was observed. In addition, when the insulation resistance of 1000 m of the winding wire of the present invention was measured, it was 1.2 kV on average.

In order to compare with the winding of the present invention, a comparative winding was obtained in the same manner as in Example 1 except that the above-mentioned dissolution treatment was not performed. When this winding wire was subjected to the same test as above, peeling of the insulation coating was observed during twisting. Note that the insulating coating did not peel off when no humidification was performed. Furthermore, the dielectric breakdown voltage determined by the reel withstand voltage test was 0.66 kV on average.

Example 2 A 0.326φ copper wire (H material) was coated with urethane paint on the outside at a wire speed of 120 m/min, and the furnace temperature was 350°C.
On a line that manufactures winding wires with a 12μ thick urethane coating, the baking process is repeated five times.
Before the urethane coating process mentioned above, please use Hofutsu Copper in advance.
A treatment tank in which a mixed solution of 100 g ^- m / and 100 g of hydroborofluoric acid was circulated at 35°C, and a skin pass wire drawing section were provided.

The treatment tank consisted of a first tank with a length of 2 m and a second tank with a length of 3 m. A copper plate was installed at the bottom of each tank, connected to the husband's power source, and a current of 6 A was applied.

After the copper wire was run through the treatment tank, it was washed with a water jet, and then drawn using a 0.320φ diamond die using 1% soap as a lubricating oil.

After drawing the wire, it was washed with hot water, and then a predetermined urethane paint was applied and baked to obtain the winding wire of the present invention.

The thus obtained winding wire of the present invention was heated at 55°C with a relative humidity of 95%.
Although it was left in the tank for 50 hours, no discoloration was observed in the conductor wire. Also, when the number of sparks was detected by passing it through a continuous spark tester under the conditions of 450V (DC) and 1MΩ, it was found to be 0 sparks/100Kg bobbin.

In order to compare with the winding of the present invention, a comparative winding was manufactured in the same manner as in Example 2 without performing the above-mentioned melt deposition process, and a moisture resistance test was conducted in the same manner as above. As time passed, discoloration of the conductor was observed. Also, the number of sparks is 22
KE/It was a 100Kg bobbin.

Example 3 Formal paint was applied to the outside of a 0.76φ copper wire (material A) at a linear speed of 90 m/min, and baking was repeated 4 times at a furnace temperature of 400°C to form a formal coating with a thickness of 25μ. On the line that manufactures winding wire,
Sulfuric acid 50 °C at 50 °C before the above formal application step.
g/first tank with a length of 1 m in which the solution circulates and copper sulfate
A second tank with a length of 1 m containing 60 g ^- m / of sulfuric acid and 40 g of sulfuric acid was installed, and the copper wire was run through 8 turns, 4 times each, using a direction changing roll (300φ) outside the tank.

In addition, a copper plate was placed as a counter electrode in the first tank, and the first DC power supply was connected to it, and the two conversion rolls attached to the first tank were also connected as power supply contacts. The second power supply was also connected with the polarity opposite to that described above. 60 each,
After processing with 50A current, wash with water, then
The wire of the present invention was obtained by drawing the wire through a 0.750φ diamond die, washing it with hot water, and applying formal paint and baking it.

When the appearance of 100 m of the thus obtained winding wire of the present invention was checked, no abnormality was observed.
Also, when we conducted a continuous spark test under the conditions of 1000V (DC) and 10MΩ, we found one spark per 500Kg.

In addition, in order to compare with the winding of the present invention, the above-mentioned dissolution precipitation treatment was not performed, and all other conditions were as in Example 3.
A comparative example winding was obtained in the same manner. When we checked the appearance of this winding, we found 4 defective parts caused by foam particles in 100m. Also, the number of sparks is 19
It weighed 500kg.

As detailed above, the method of the present invention has remarkable effects such as being able to manufacture winding wires with excellent quality and performance.

[Brief explanation of the drawing]

1 to 3 are schematic explanatory diagrams showing one example of the melting and precipitation steps in the method for manufacturing a winding wire according to the present invention. a...Copper wire, 1...Dissolution tank, 2...Precipitation tank, 11,1
2... Electrode, 13, 14... Contact, 15... Shielding plate.

Claims (1)

[Claims] 1. A first method for electrolytically dissolving a copper wire as an anode.
step, and a second step in which electrodeposition is performed using the copper wire as a cathode.
a third step in which the electrodeposited copper wire is drawn using at least one die; and a fourth step in which the drawn copper wire is used as a conductor and an insulating paint is applied and baked on the outside.
A method for manufacturing a winding wire, characterized by the following steps: 2. Electrolytic treatment can be carried out by disposing electrodes in the dissolution tank and precipitation tank, respectively, and contacting the electrodes with the positive and negative electrodes of the same power source, by contactlessly supplying electricity without mechanically contacting the electrodes with the copper wire. A method of manufacturing a winding wire according to claim 1, wherein the method comprises: 3. The method of manufacturing a winding wire according to claim 1, wherein the first step to the fourth step are performed continuously on the same line.