JPS6034207B2 - Manufacturing method of insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the method of manufacturing insulated wires such as windings by lightning coating.

The coating film deposited on the conductor by electrodeposition has a structure in which deposited resin particles are piled up in a stone wall shape, so it can be left untreated).
Baking causes insufficient fusion between the precipitated resin particles,
Due to the problem of pinholes remaining in the baked coating,
A technique has been proposed in which the precipitated resin is brought into contact with a soluble solvent before dawn, and the precipitated resin is swollen to promote fusion between the particles to some extent.

In that case, in order to treat the electrocoated film, which is a continuum, in a liquid solvent bath, the structure of the solvent, especially the introduction port for the electrocoated wire, is complicated. It is also proposed to do so. By the way, the high-temperature vapor of the solvent generally has an excessively high dissolving power for the precipitated resin, which leads to excessive dissolution, which deteriorates the appearance after baking, and which may cause new problems such as deterioration of the withstand voltage characteristics and smoothness of the coating film. On the other hand, if the processing time is shortened, the processing becomes uneven.

In view of the above, the present invention proposes a novel method for manufacturing insulated wires using a lightning coating that solves such problems, and in which the lightning coating is coated with the above-mentioned solvent, which is atomized at a temperature below the boiling point. It is characterized by post-processing inside.

As the solvent used in the present invention, those known as post-treatment solvents for insulated wires with haze coating are used. For example, when the deposited resin is an acrylonitrile resin, dimethylformamide, dimethylacetamide, etc. For resins, phenol etc. are used.

In order to atomize the solvent at a temperature below its boiling point, the solvent vapor at a high temperature above its boiling point is cooled to a low temperature below its boiling point. This can be done by a method such as spraying a liquid solvent. The temperature of the solvent mist during post-treatment of the electrodeposited coating is preferably from room temperature to about 100 CO.

The post-treatment time (contact time between the solvent mist and the exposed coating film) is 2.
Appropriate is a sand size of 3 seconds to 6 seconds, preferably a sand size of 3 seconds to 3 seconds. Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 Steam obtained by boiling dimethylformamide was continuously introduced into a cold room to generate a mist of dimethylformamide in the room.

The temperature of the fog at room temperature was 80±5°C. Using a water-dispersed varnish of acrylonitrile resin (resin concentration 2% by weight), line speed 20/min was applied onto the copper conductor on the 0.5 side.
Acrylonite under the condition of a layer voltage of 5V. A hazy coat of rill resin was formed, and the conductor with the coated film was continuously passed through the chamber filled with the dimethyl formamide mist for a passage time of 5 seconds.
000 and then at 40,000 to obtain an insulated wire with an acrylonitrile insulation coating thickness of 0.025 mm. Comparative Example 1 An insulated wire was manufactured, differing from Example 1 only in that the post-treatment of the haze layer was performed with 15,000 ml of dimethylformamide vapor.

Example 2 An insulated wire was manufactured, differing from Example 1 only in that the exposed layer was post-treated in a mist of 7000 ml of dimethylacetamide.

The appearance and withstand voltage characteristics of the insulated wires obtained in Examples 1 and 2 and Comparative Example 1 are shown in the table below.

Claims (1)

[Claims] 1 In the production of insulated wires in which the electrodeposited coating is post-treated with a solvent that is soluble in the resin constituting the electrodeposition coating and then baked, the above-mentioned post-treatment is atomized at a temperature below the boiling point. A method for producing an insulated wire, characterized in that it is carried out in the above solvent.