JPS58198803A - Method of producing 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 The present invention relates to a method for manufacturing an insulated wire, and particularly to a method for manufacturing an insulated wire used as a wire for a high-voltage rotating electrical machine coil.

Conventionally, when insulating the bare wires of rotating electric machine coils, for low-voltage rotating electric machines, there are methods such as taping bare copper wires with thin polymeric materials such as polyimide film or Nomex paper, or baking an enamel NfjL film and then applying further insulation. The mainstream method is to wrap glass fibers, and for high-voltage rotating electric machines,
The main method of taping was mica tape backed with glass fiber or polyester film.

However, the method of taping thin polymer materials or the method of wrapping glass fiber after enamel baking requires time in the taping process, and when using mica tape backed with mica fiber or polyester film, This method requires a process of gluing the mica and the back nail material, which has the disadvantage of being extremely expensive.

In order to eliminate the drawbacks of the above-mentioned method, the inventors of the present invention have attempted to eliminate the drawbacks of the above-mentioned method, for example, by using the method described in Japanese Patent Application Publication No. 2003-120002. :9 parts 7g, Tokukai Akira/-7
No. 79402 and JP-A No. 11-403 have proposed an electrodeposition coating method using a water-dispersed phenol mixed with mica scales. When insulation is applied to bare copper wires with a thickness of 70% to 95%, damage such as cracking and peeling occurs when molded into a formed coil, making it unsuitable for practical use.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional methods, and provides a manufacturing method that allows insulated wires to be obtained continuously in a straight line and without breakage when formed into a coil. The purpose is to

! 1. In order to achieve the above object, the present invention uses electrodeposition paint to produce insulated wires for use in rotating electric machine coils, and uses scaly mica powder and a film whose thermal softening temperature after heating is 6.
An electrodeposition coating is prepared by dispersing flexible polymer particles at a temperature of 0°C or lower in water, and an electrodeposition layer is formed on a straight continuous copper wire using the electrodeposition coating method, followed by heating. It is characterized by

As the flaky mica used here, natural mica is suitable, and both soft mica and soft mica are applicable.

In addition, the particle size of the flaky mica is preferably one that has passed through a 3S mesh sieve; if the particle size is larger than that that has passed through a 35 mesh sieve, the appearance of the electrodeposited layer will deteriorate, resulting in peeling. .

Further, if the particle size is smaller than that passing through 35 meshes, the mechanical strength of the electrodeposited layer obtained will be weak, and the insulation properties will be poor when it is finally used as coil insulation.

The polymer particles to be used are preferably those dispersed in water, but it is preferable to use polymer particles alone to form a film by heating and have a heat softening temperature of 60°C or less. If the thermal softening temperature of the film is 60'G or higher, the mechanical strength of the electrodeposited layer (3) obtained is so low that it cannot withstand shocks such as when forming a coil. Suitable aqueous dispersions include butadiene-modified epoxy emulsions, emulsions containing polyether acrylate as a main component, and the like. In addition, the ratio of the scale-like mica having the above particle size and the polymer particles is 25 to 100 parts by weight of the scale-like mica to 100 parts by weight of the scale-like mica.
Parts by weight, preferably 2S to 75 parts by weight. If it is less than 25 parts by weight, the mechanical strength of the electrodeposited layer obtained is weak and cannot withstand the impact of coil forming, etc. If it is more than 100 parts by weight, the degree of impregnation of the impregnated resin in the subsequent process may be insufficient. However, the insulation characteristics such as dielectric breakdown voltage and -δ of the obtained rotating electric machine coil deteriorate.

Although the electrodeposition voltage depends on the distance between the electrodes, a suitable voltage is from θ to 10 θV. In addition, the temperature when heating the obtained electrodeposited layer to volatilize the water content is preferably in the range of 70,080 to 300°C, and 100°C.
If the temperature is lower than 1.7000℃, the drying time will be long and it is not suitable for practical use. I can't.

Hereinafter, explanation will be given with reference to comparative examples and examples, and an example of manufacturing an aqueous dispersion of polymer particles will be described.

Production of aqueous dispersion A Ehicoat/θθ/(manufactured by Shell Chemical Co., Ltd.) 100θ parts,
22 g of tetrahydrophthalic anhydride, 37 parts of ethylene glycol, and 0.00 parts of oxidized phthalic anhydride were charged into four flasks and reacted with nitrogen gas at /lIO to /l°C for /S hours to form an acid-added epoxy with an acid value of about SO. Get resin. Next, add lauri A (j [ester soda 7
Pour 100 parts of ion-exchanged water containing 0 parts of ammonia water (X, t%), raise the temperature to 0°C, add 100 parts of acid-added epoxy resin, and remove excess ammonia and water by passing nitrogen through. Stir for 3 hours while evaporating, and adjust pH to 2.
&, obtain an aqueous dispersion of % solids/g%. This aqueous dispersion was electrodeposited on a copper plate by a conventional method, and the electrodeposited layer was immersed in ethyl cellosolve for about 30 seconds, then at gθ℃ for 3θ minutes, /Sθ
” If heated for 1 hour at ℃, the thermal softening temperature of the baked film will be approximately /
/θ°C.

Preparation of aqueous dispersion B In a four-loaf flask, hydroxyl-terminated polybutadiene (G-/θ
θθ manufactured by Nisso) / 31 Iθ parts, 3 g of trimellitic anhydride
11 parts of hydroquinone θθθ/left part were charged, and the mixture was stirred at 190° C. for about 30 minutes while passing nitrogen gas to obtain an acid-added epoxy resin. Next, the temperature/! IO” (:, after the lower digit, Epicoat Zako g (Shell Chemical Co., Ltd.) gSθ part, Epicoat lOO/(Shell Chemical Co., Ltd.) qso part, tetrahydrophthalic anhydride 1000 parts, ethylene glycol 30 parts, xylene, 200 , /daθ~/4'
The acid value is 4-. 5-butadiene-modified epoxy resin is obtained. Next, 10 parts of lauryl sulfate sodium ester, 20 parts of ammonia water (X, t%), and 'yoo parts of ion exchange water were added to another three-bottle flask.
The temperature was raised to about 70°C, 700 parts of the above resin was added, and while nitrogen gas was passed through to volatilize excess ammonia and moisture,
Stir for about 3 to 30 minutes to obtain an aqueous dispersion with pI (about 1 t, approximately 1% solids). This aqueous dispersion was prepared in the same manner as aqueous dispersion A, and the thermal softening temperature of the baked film was about SO°C. Met.

Preparation of aqueous dispersion C In a fourth flask, add 10 parts of lauryl sulfate ester soda.
1.230 parts of ion-exchanged water, ethyl acrylate/! ;
0 parts, 30 parts of acrylonitrile, 70 parts of glycidyl methacrylate, and 70 parts of methacrylic acid, heated to about 65°C through nitrogen gas, and then ammonium persulfate,
20 parts of sodium bisulfite, 5 parts of ion-exchanged water
Add the solution dissolved in 0 parts and react at 70°C for ~5 hours to obtain an aqueous dispersion with a pH of about 5 and a solid content of 2g%.

The thermal softening temperature of the baked film obtained by using this aqueous dispersion in the same manner as aqueous dispersion A was about 10°C.

Although typical examples of aqueous dispersions have been described above, comparative examples and examples will be explained using the above aqueous dispersions.

Comparative Examples/~3 Water dispersion shown in Table/ and mica were mixed to obtain an electrodeposition paint with a non-volatility of approximately 13% at the mica/water dispersion ratio shown in Table/. This electrodeposition paint was put into the Picaco (7), and using a model device as shown in Figure 1, the thickness -I was measured.
A DC voltage of approximately SOV was applied to the rectangular copper wire 3 having a width of Im width Qmg to obtain an electrodeposited layer, and then heated at θθ°C for 10 minutes.
An insulating film with a thickness of Q/2m is obtained. In Fig. 1, ``Teda'' is a starte, and ``S'' is a stirrer. The properties of this film are shown in Table 1. Next, the obtained film was vacuum impregnated with an epoxy impregnating resin (Siloza 6-/ manufactured by Ryoden Kasei) and cured at 30° C. for 70 hours to obtain a complete insulating film. The properties of the obtained film are shown in Table 7.

(g) All impregnated varnishes are epoxy type bgb-i) Abrasion resistance is measured using a JIS abrasion tester under load 'yoθg, mouth) DuPont impact tester (100θ17//-inch height at which no cracks occur) cIL) C) Cylindrical diameter that does not cause cracks or peeling when wrapped around a cylinder, 2) 2000C: 10-day thermal deterioration examples 7 to 6 Using the aqueous dispersion shown in Table/, and mica/ Table 7 shows the properties before and after impregnation obtained in the same manner as in Comparative Example 1 using an electrodeposition paint having the proportion of an aqueous dispersion.

As is clear from Table 7, the insulated wire produced by electrodepositing scale-like mica grains using an aqueous dispersion and drying according to the manufacturing method of the present invention has excellent mechanical strength, and is not subject to harsh conditions such as coil forming or assembly. In addition, the insulating film impregnated with impregnated resin and cured has an excellent breakdown voltage, and can be used satisfactorily as wire insulation for high-voltage rotating machine coils.

In order to continuously manufacture an insulated wire by the method of the present invention, for example, as shown in FIG. Electrodeposition can be carried out by an apparatus such that the material is electrocoated while being continuously passed through a tank/y, then heated through a drying oven/S, and wound onto a reel/6. The insulated wire thus obtained can be applied to wire insulation for DC machines, electric train motors, induction motors, and the like.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of a model device for electrocoating copper wire by the method of the present invention, and FIG. It is. /...mica-containing aqueous dispersion, copying force, 3°/, 2
・・Flat conductor, ・・・Star 2, S・・ Stirrer, //,
/A...Reel, 13...Electrodeposition paint tank, llI...
Electrodeposition bath, evening...drying oven. In addition, the same symbols in each figure indicate the same + or corresponding parts.

Claims (1)

[Scope of Claims] (1) A step of forming an electrodeposited layer on the surface of a bare copper wire by an electrophoretic coating method using an electrodeposition paint containing mica powder, and a step of heating the electrodeposited layer. A method for manufacturing an insulated wire, comprising: (2) The method for manufacturing an insulated wire according to claim 1, wherein the electrodeposition coating material includes a liquid in which mica powder and polymer particles are dispersed in water. (3) The method for manufacturing an insulated wire according to claim 1, wherein the electrodeposition paint is an aqueous dispersion of 2S to 100 parts by weight of polymer particles based on 700 parts by weight of mica powder. (4t) The method for manufacturing an insulated wire according to claim 1, wherein the mica powder is passed through a 35-mesh sieve. (5) The method for manufacturing an insulated wire according to claim 1, wherein the polymer particles have a thermal softening temperature of 40° C. or lower after heating.