JPS63205011A - Manufacture of insulated wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a method for manufacturing an insulated wire having an insulating film having excellent dielectric strength and solvent resistance.

"Prior Art and its Problems" Conventionally, various enamelled wires have been provided as insulated wires. Among such enameled wires, for example, polyurethane enameled wire (hereinafter referred to as "UEW"), which can be wired without peeling off the insulation film, is known to have good connection workability.

This UEW is made by applying a polyurethane resin film onto a conductor and then baking this face onto the conductor to form an insulating film made of polyurethane resin.

However, in Una UEW, the burning process depends on the process.
Although efforts are being made to improve the solvent resistance of the insulating film, the insulating film may still swell due to organic solvents such as xylene or acetone, or the insulating film may be extracted into the organic solvent. I was dissatisfied with my sexuality. Also,
During the process of applying and baking enamel paint onto conductors, air bubbles may be generated in the paint, and in this case, the air bubbles may remain as pinholes in the insulation film, which may reduce the dielectric strength of the insulation film. Ta.

"Means for Solving the Problems" Therefore, the present invention aims to solve the above problems by forming a polymer insulation film on a conductor by an electrolytic polymerization method.

Hereinafter, the present invention will be described in detail with reference to the drawings.

The drawings show an example of a manufacturing apparatus that can be suitably used to carry out the insulated wire manufacturing method of the present invention. In this manufacturing device, a conductor l made of copper or aluminum is first sent out from a delivery roll 2,
Through the metal guide roll 3, the electrolytic bath 5 of the electrolytic polymerization tank 4
guided inside.

Here, a plate-shaped electrode 6 arranged in this electrolytic bath 5 is electrically connected to the guide roll 3 via a power source 7, and this electrode 6 is used to conductor l during electrolytic polymerization to be described later. It is the opposite. The electrode 6 is made of platinum, gold, or the like.

The electrolytic bath 5 is made of a monomer of a material forming an insulating polymer film, which will be described later, a solvent, and a supporting electrolyte. For example, monomers include five-membered heterocyclic compounds such as pyrrole, thiophene and furan, aniline derivatives such as aniline and medylaniline, benzene and benzene derivatives such as biphenyl and terphenyl, 0-aminophenol and 2-amino-3-methyl. Phenol, 0-aminophenol derivatives such as 2-amino-6-methylphenol, 2-medylaminophenol, etc. are used, but are not limited thereto. As the solvent, a solvent is selected that dissolves the monomer and does not react with the supporting electrolyte, and specifically, water, acetonitrile, propylene carbonate, etc. are suitable, but the solvent is not limited thereto.

In addition, as supporting electrolytes, chlorides such as LiCQSNaCff, perchlorates such as LiCl20CC, H9), N CQO, TBACdO, (C4H11)4N
Tetrafluoroborates such as BF4, TBABF'4, sulfates such as Na, 804, CF3CO0Na
Although tetrafluoroacetates such as , etc. are used, it is desirable to use perchlorate, HCl2, H2SO, CF3CO0Na, and to make the electrolytic bath an acidic bath with a pH of 6 or less, preferably 3 or less. The origin of the supporting electrolyte in the 71 bath solution 5 is determined by the type of supporting electrolyte, the thickness of the insulating film finally obtained, etc.
It is usually in the range of about 0.1-1 mol/di. Further, the concentration of the monomer in the electrolytic bath 5 varies depending on the type of monomer, but is usually determined within a range of about 0.01 to 0.5 mol/Q.

Next, in such an electrolytic bath 5, electrolytic polymerization is performed to form a polymer film on the running conductor l. Electrolytic polymerization is carried out by applying a voltage between the conductor I and the electrode 6 using the power supply 7 so that the conductor I has a positive or negative potential with respect to the electrode 6, and the monomer in the electrolytic bath 5 is The polymer is polymerized on the surface of the running conductor 1, and a polymer film made of this polymer is uniformly formed. The electrolytic conditions for this electrolytic polymerization are determined by taking into consideration various conditions such as the outer diameter of the conductor I, the thickness of the polymer film, the type and concentration of the supporting electrolyte in the electrolytic bath 5, and the running speed of the conductor I. The current density is usually about 0.1 to 5 zA/cJI', but is not limited thereto. Furthermore, the electrolysis time for the conductor 1, that is, the time for the conductor 1 to pass through the electrolytic bath 5, depends on the running speed of the conductor 1, the length of the conductor 1 immersed in the electrolytic bath 5, etc., and the final insulation Determined by the film thickness of the film.

The thickness of the polymer film obtained in this way is determined depending on the type of polymer forming this polymer film and the thickness of the final insulation film. For example, the wire diameter of the conductor l is
If it is about OμIII to 1■, 1 to 200 μm
However, it is not limited to this range.

Anions and cations derived from a supporting electrolyte are introduced into the interior of such a polymer film as a dopant during electrolytic polymerization, and these dopants exhibit electrical conductivity. Therefore, depending on the level of conductivity of the polymer film, it is necessary to make the polymer film an insulator. In such a case, the conductor 1 is sent to an insulating tank 8 adjacent to the electrolytic polymerization tank 4, where the polymer film of the conductor 1 is subjected to a dedoping treatment.

There are chemical methods and electrochemical methods for this dedoping treatment, and the drawing shows an insulating tank 8 that is preferably used for treatment by the chemical method.

In the dedoping treatment by a chemical method, if the dopant introduced into the polymer film is a cation, a solution containing an oxidizing agent is used as the treatment liquid 9 in the insulating tank 8, and if the dopant is an anion, a solution containing an oxidizing agent is used. This is carried out by using a solution containing a reducing agent as the processing liquid 9 and inserting the conductor 1 into the processing liquid 9 for a predetermined period of time. The oxidizing agent or reducing agent used in the treatment liquid 9 is appropriately selected and used depending on the type of dopant, and is not particularly limited. Time during which conductor l is immersed in processing liquid 9 (processing time)
What is the thickness of the polymer film and the progress of dedoping? The duration may be adjusted as appropriate, but the duration is approximately 1 to 20 minutes.

Further, dedoping treatment by an electrochemical method is carried out by applying a potential in the opposite direction to the potential during electrolytic polymerization to the polymer film.

The electrolytic conditions in this treatment are almost the same as those in the electrolytic polymerization described above, except that the direction of the potential is different. As the treatment liquid 9 used in this treatment, the electrolyte bath 5 described above with the monomer removed can be used.

By converting the polymer film into an insulator in this manner, the desired insulated wire IO is obtained, and this insulated wire IO is wound up by the winding roll 11. The running speed of the conductor 1 is adjusted by controlling the rotational speed of the take-up roll 11, but the running speed is kept approximately constant during the process.

The insulated wire 10 thus obtained has excellent dielectric strength and is resistant to organic solvents, etc., since its insulating film is made of a polymer film formed by electrolytic polymerization and made into an insulator by dedoping treatment. It is extremely stable against solvents. Therefore, according to this method, an insulated wire with high dielectric strength and solvent resistance can be manufactured.

In addition, in this method, the surface of the conductor 1 or the insulation coating surface of the insulated wire 10 may be cleaned by guiding the conductor 1 to a cleaning tank (not shown) before electropolymerization or after dedoping treatment, respectively, as necessary. can. As the cleaning bath in the washing/'P tank, an acidic bath with a pH of 6 or less or a neutral water bath is selected depending on the purpose of cleaning.

Furthermore, when manufacturing large-diameter insulated wires, for example, a cylindrical electrode is used as the electrode (counter electrode of the conductor) in the electrolytic bath, and the conductor is inserted into the cylindrical electrode. It becomes easy to uniformly form a polymer film thereon, and therefore it becomes possible to manufacture large-diameter insulated wires having a uniform film thickness.

"Example" In the manufacturing equipment shown in the drawings, a copper wire with a diameter of 15μ was inserted into the electrolytic bath of the electrolytic polymerization tank for about 1 minute, and then into the dedoping treatment solution of the insulating tank for about 1 minute. An insulating film with a thickness of 3 μm was formed on the conductor to produce an insulated wire (example) having a wire diameter of about 21 μm. During this production, the running speed of the conductor was 21/min, and the electrolytic bath was 0.2 mol/min.
Using an aqueous solution of 12LicQo, -HCl2O, (pi-11,0), the thiophene concentration in this aqueous solution was set to 0.1.
It was set as mol/Q. Then, the current density during electrolytic polymerization is lz
It was set to A/c12. Further, as a treatment solution for the dedoping treatment, an aqueous solution of sodium hydrosulfide (N at s t 04) with a concentration of 0.5 moQ/Q was used.

On the other hand, a UEW with a wire diameter of 21 μm was used, in which a copper wire with a diameter of 15 μπ was coated with an insulating film having a thickness of 3 μm (comparative example).

Next, each of these electric wires was subjected to a pinhole test and a solvent resistance test, and the results are shown in Table 1. In the Vinpol test, each electric wire (12 pieces each) is immersed in a test liquid containing a 3% alcohol solution of phenolphthalein and a 0.2% NaC & aqueous solution mixed at a ratio of 1:1O, and the conductor of each wire and the test A voltage of 12V is applied between each
After application, the insulating film was visually observed to determine the number of pinholes. In addition, the solvent resistance test is 60
After immersing each wire in xylene at °C for 24 hours, the wire diameter of the wire was determined using an optical microscope. Evaluation was made using the wire diameter x 100).

Table 1 As is clear from Table 1, the example has superior dielectric strength compared to the comparative example because it is pinhole-free, and is extremely stable against solvents because of its small degree of swelling. I understand.

Next, a dielectric strength test was conducted on each of the above electric wires.

This test method is based on JIS, and Na112
Immerse the wire in saturated glycerin (immersion length 25 cIN)
After immersing the copper plate as a counter electrode, connect the positive electrode to the wire conductor.
The test was carried out by applying a negative voltage to the counter electrode, and the results are shown in Table 2.

As is clear from Table 2, the examples showed almost the same absolute proof strength as the comparative examples, had excellent insulation properties, and were found to be fully usable for practical use.

"Effects of the Invention" As explained above, according to the present invention, it is possible to form an insoluble and infusible insulating film with a high degree of cross-linking on a conductor, so that the insulating film is pinhole-free, has excellent dielectric strength, and is stable against solvents. An insulated wire with a film can be manufactured.

[Brief explanation of the drawing]

The drawing shows the insulation '2+' of this invention! FIG. 1 is a schematic configuration diagram showing an example of a manufacturing apparatus suitably used in carrying out a wire manufacturing method. l...Conductor, IO...Insulated wire.

Claims (1)

[Claims] A method for manufacturing an insulated wire, comprising forming a polymer insulation film on a conductor by electrolytic polymerization.