JP3090348B2 - Manufacturing method of tape wound insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a polyimide tape insulated wire having high heat resistance and having no adhesive layer.

[0002]

2. Description of the Related Art Conventional insulated wires for high heat resistance are produced by winding a commercially available polyimide tape such as a Kapton (made by Toray DuPont) film with a fluororesin adhesive or the like around the core wire and firing it. It is manufactured by directly immersing the core wire in a polyamic acid varnish that is a precursor of polyimide, and then heating and drying and imidizing it.However, the former is not sufficient in heat resistance because it uses a fluororesin or the like as an adhesive. In the latter, it is difficult to arbitrarily control the thickness of the polyimide layer because the core is immersed in the varnish.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyimide tape wound insulation without an adhesive layer, which makes use of the inherent alkali resistance, solvent resistance, heat resistance and electric characteristics of polyimide. An object of the present invention is to provide a method for manufacturing an electric wire.

[0004]

SUMMARY OF THE INVENTION The present invention is a method for producing a tape-wound insulated wire, comprising winding a polyamic acid tape around the outer periphery of a core wire and heating and drying to imidize the tape.

That is, a polyamic acid solution is applied on a release film or a release drum, and dried until a tack-free state is obtained, thereby forming a polyamic acid film. Thereafter, this film is slit into a predetermined width together with the release film or only the amic acid film to form a polyamic acid tape. After winding the tape around the core wire, the tape is sufficiently heated and dried to perform imidization.

In the present invention, the conditions for drying the polyamic acid solution to form a semi-cured polyamic acid film may be such that the film is tack-free and there is no problem in workability. ,Five~
30 minutes is appropriate. If the temperature is lower than this, and the time is short, the amount of the residual solvent remaining in the film is large, and the variation in the coating thickness becomes large, and it is difficult to control the thickness to a predetermined value. If the temperature is higher and the time is longer,
The imidization proceeds too much, the fluidity of the film is lost, and the adhesion to the core wire and the adhesion between the films become insufficient.

[0007] The polyamic acid in the present invention is usually obtained by reacting a diamine with an acid anhydride.
Examples of the diamine include phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and diaminodiphenylether.Examples of the acid anhydride include trimellitic anhydride, pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, and benzophenonetetracarboxylic acid. Dianhydrides and the like can be used.
Species or a combination of two or more can be used as appropriate. The imidation ratio in the state of the polyamic acid film is preferably from 10 to 50%, and more preferably from 20 to 40%.

Examples of the material that can be used as the release film include plastic films such as polypropylene, polyester, polyethersulfone, polyimide, and polyethylene.

Materials that can be used as the core of the electric wire include copper, aluminum, constantan, nickel and the like.

[0010]

According to the present invention, by utilizing the ease of molding and the mechanical strength of the polyamic acid film, a polyamic acid tape is wound around the outer periphery of the core wire and heated and dried to form an imidized film. Good yield, the inherent alkali resistance, solvent resistance, heat resistance of polyimide,
It is possible to obtain a polyimide tape wound insulated wire having no adhesive layer and utilizing the electrical characteristics as it is.

[0011]

EXAMPLE A 4-neck separable flask equipped with a thermometer, a stirrer, a reflux condenser and a dry nitrogen gas inlet was charged with 108 g of purified anhydrous paraphenylenediamine and 4,
Take 200 g of 4'-diaminodiphenyl ether, add a mixed solvent of 90% by weight of anhydrous N-methyl-2-pyrrolidone and 10% by weight of toluene to a solid content ratio of 20% by weight in all the raw materials.
Was added and dissolved. Dry nitrogen gas was allowed to flow throughout the entire process from the preparation of the reaction to the removal of the product. Next, 294 g of purified anhydrous 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 218 g of pyromellitic dianhydride are added little by little with stirring, but the reaction is exothermic. This was cooled by circulating cold water at about 15 ° C. After the addition, set the internal temperature to 20 ° C,
After stirring for 5 hours, the reaction was completed to obtain a polyamic acid solution.

The thickness of this polyamic acid solution after imidization with a bar coater on a commercially available polyester film is
Apply to 50 μm, dry at 110 ° C for 15 minutes,
A polyamic acid film with a release film was obtained.
This film was slit to a width of 20 mm while peeling off the release film using a slitter to obtain a polyamic acid tape. After winding this tape three times on the core wire, it was heated and dried at 380 ° C. for 1 hour and imidized to obtain a polyimide tape wound insulated wire. The properties of the obtained tape wound insulated wire were excellent heat resistance (solder heat resistance, 360 ° C., 1 minute) and chemical resistance inherent to polyimide.

[0013]

According to the present invention, it is possible to obtain a tape-wound insulated wire consisting only of a polyimide layer having no adhesive layer, and further to a continuous process using a normal tape-wound insulated wire manufacturing apparatus as it is. Can also be easily applied,
It is suitable as an industrial method of manufacturing a tape wound insulated wire.

Claims (1)

(57) [Claims] 1. A method for producing a tape-wound insulated wire, comprising winding a polyamic acid tape around the core wire and heating and drying to imidize the tape.