JP3141386B2 - Self-fusing insulated wire and coil using the same - Google Patents

Description

The present invention relates to a self-fusing insulated wire having excellent fusibility.

(B) Conventional Techniques and Problems Self-fusing insulated wires have the advantage that the work steps can be shortened because the wires can be fixed without using an impregnating varnish during coil production. However, although the use of self-fusing insulated wires is increasing, the applications used are limited because of the following two problems,
Still only a small part.

First, the self-fusing insulated wire, which is the most important characteristic of the insulated wire, is insufficient in fusing force. In particular, butyral resin and phenoxy resin, which have poor fluidity at the time of fusion, have a large shortage of fusion force, and polyamide resin having excellent fluidity has a problem that the fusion force is not sufficient. Furthermore, when the self-fusing insulated wire is formed into a coil shape, depending on the shape of the coil, a portion having a small line density is generated,
There is also a problem that the fusion force is particularly insufficient due to little adhesion between the electric wires.

The second problem is that since the thickness of the fusion layer is large, the space factor representing the cross-sectional area of the electric wire occupying a certain space is small. In recent years, with the miniaturization of equipment, coils,
As motors become smaller, more enamel wire is packed in a smaller space, and it is desired to improve the space factor of electric wires. Therefore, it is preferable that the film thickness of the fusion layer be as thin as possible as long as the fusion force is not impaired, because the space factor is improved. However, the thickness of the currently used fusion layer is about 1/2 to 1/3 of the thickness of the insulating layer, and there is a problem that the space factor cannot be improved so much.

(C) Constitution of the invention The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, during fusion, the fusion layer is foamed at the time of fusion so that the fusion force is excellent and the fusion layer can be made thin. Invented a self-fusing insulated wire.

That is, the present invention is a self-fusing insulated wire characterized in that a fusion layer foamed at the time of fusion is formed on a metal conductor via an insulating layer.

Hereinafter, the present invention will be described in detail. The method for foaming the fusion layer in the present invention is a method using a foaming agent. A method of vaporizing by mixing or impregnating a low boiling volatile solvent.
A method of including microballoons. Is possible.

First, in the method using a foaming agent, the foaming agent used in the present invention decomposes by heating to generate nitrogen gas, carbon dioxide gas, carbon monoxide, ammonia gas, etc., and refers to an organic foaming agent, an inorganic foaming agent. Can be used.

Examples of organic foaming agents include, for example, azodicarbonamide (A, D, C, A) for azo type, azobisisobutyronitrile (A, I, B, N) and dinitrosopentamethylenetetramine (D) for nitroso type. , P, T) N, N 'dinitroly N, N'-dimethylterephthalamide (DNDMTA) In the hydrazide system, P-toluenesulfonylhydrazide (T, S, H) P, P'-oxybis (benzenesulfonylhydrazide)
(O, B, S ', H) Benzenesulfonyl hydrazide (BS'H) In addition, trihydrazinotriazine (THT) acetone-P-sulfonylhydrazone, etc. Each of which has different decomposition temperature and generated gas amount is commercially available Have been. These can be used alone or in combination of two or more kinds dissolved or dispersed in a fusion coating. Further, the decomposition temperature and the decomposition rate can be controlled by a foaming aid as needed.

As a foaming aid that promotes foaming, for example, zinc white,
Inorganic salts such as zinc nitrate, lead phthalate, lead carbonate, and tribasic lead phosphate, metal soaps such as zinc fatty acid soap, lead fatty acid soap, cadmium fatty acid soap, borax, oxalic acid, succinic acid, and adipic acid Examples include acids, urea, biurea, ethanolamine, glycol, glycerin and the like. Conversely, as foaming aids for suppressing foaming, for example, maleic acid, fumaric acid, organic acids such as 1,2-phthalic acid, stearoyl chloride, halogenated organic acids such as phthaloyl chloride, maleic anhydride, anhydride Examples include water organic acid anhydride polyhydric alcohols such as phthalic acid, phosphates, tin compounds, and the like.

On the other hand, examples of the inorganic blowing agent include sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, sodium borohydride, sodium boron hydride, and silicon oxyhydride. Organic foaming agents are preferred because they are slower than organic foaming agents and difficult to control gas generation.

The decomposition temperature of the foaming agent depends on the welding conditions of the self-fusing insulated wire.
Since it is 150 ° C to 200 ° C, 150 ° C to 200 ° C is desirable. The amount of the foaming agent is 0.1 PHR based on the fusion resin.
~ 50 PHR is preferred. If the amount of the foaming agent is 0.1 PHR or less, the effect of improving the fusion force by foaming is small, and if it is 50 PHR or more, the mechanical strength of the fusion layer is insufficient and the control of the foaming speed becomes difficult. In order to obtain more stable foaming, the addition amount of the foaming agent is more preferably 1 PHR to 25 PHR.

Next, as the volatile solvent used in the method of vaporizing by mixing or impregnating a volatile solvent having a low boiling point, alcohol-based, ketone-based, aromatic hydrocarbon-based, and water are used. A paint containing these solvents can be baked at a low temperature to form a fusion layer, and the solvent remaining in the film at the time of fusion is volatilized to foam the film.

In the method using a micro balloon, nitrogen gas,
Microballoons containing carbon dioxide gas, ammonia gas and the like can be used, these are dispersed in the fusion layer, and the fusion balloon is foamed by thermal decomposition of the microballoon. Among these three methods, a method using a foaming agent is preferred from the viewpoint of simplicity in controlling foaming conditions and ease of production.

As the fusion resin used in the present invention, any resin can be used as long as it shows fluidity at a high temperature. For example, butyral resins, phenoxy resins, polyamide resins, and other thermoplastic resins can be used. For phenoxy resins, bisphenol A, bisphenol S, bisphenol F
And modified ethoxy. As the polyamide resin, various copolymerized polyamide resins, 6, nylon resin, 6,6 nylon resin, 6,10 nylon resin and the like are used as thermoplastic resins. Plastic polyurethane resin, polycarbonate resin, polyphenylene oxide resin, polyphenylene sulfide resin, polysulfone resin, polyetherimide resin, polyetheretherketone resin,
Polyether ketone resin, polyether sulfone resin,
A thermoplastic polyamide-imide resin, a thermoplastic polyimide resin, or the like can be used. Also, a melamine resin,
It is also possible to crosslink by adding a phenol resin, isocyanate, or the like, and to obtain a partially thermosetting type.

Of these resins, butyral resin, phenoxy resin, and copolyamide resin are preferable because they have a good balance of fusing force and fusing temperature and are still used for the fusing layer. Further, in the present invention, the use of a butyral resin or a phenoxy resin, which has a little difficulty in fluidity, is more preferable because the fusion layer foams and fills the gap between the wires because the effect of improving fluidity is large.

In the fusing paint used in the present invention, the fusing resin is dissolved in a solvent such as microhexanone xylene, NM2P, DMAC, DMF, cresol or the like to a concentration of about 10% to 50%, and a predetermined amount of a blowing agent is dissolved or dispersed. It can be obtained by: In the case of dispersing, a more uniform coating can be obtained by dispersing with a dissolver, a ball mill, a sand mill or the like.

There is no limitation on the insulating film used in the present invention, and any material can be used as long as it is commonly used.
For example, polyvinyl formal resin, thermosetting polyurethane resin, thermosetting acrylic resin, epoxy resin, thermosetting polyester resin, thermosetting polyesterimide resin, thermosetting polyesteramideimide resin, aromatic polyamide resin, thermosetting polyamideimide resin, heat A resin mainly composed of a cured polyimide resin can be used. The self-fusing insulated wire of the present invention can be obtained by applying and baking the above-mentioned fusing paint on these insulating films under baking conditions under which the foaming agent does not decompose.

When the obtained self-fusing electric wire is made into a predetermined coil shape and is heated by heating or hot air at a decomposition temperature of the foaming agent or more,
The fusion layer foams, and as a result, the voids of the coil are filled by the fusion layer due to the foaming, and the fusion force is remarkably improved as compared with a self-fusing insulated wire not containing a foaming agent. In particular, in the case of a coil shape, the fusion material swells due to foaming even in a place where the fusion material having a low line density is difficult to adhere, and the effect is large. In addition, since the apparent thickness of the fusion layer is increased by foaming, the same fusion force is exhibited even if the conventional film thickness is reduced to about 1/2 to 1/5, greatly contributing to the improvement of the space factor. I do.

 Hereinafter, the present invention will be described in detail based on examples.

[Comparative Example 1] A phenoxy resin (YP-50: Tobu Kasei) was dissolved in NM ₂ P to a concentration of 25% to obtain a fusion coating.

Polyesterimide varnish Isomid 40 (Nisshin Schenectady) was applied and baked on a 0.3 mmφ copper wire in a horizontal furnace having a furnace length of 3 m by a well-known method to prepare a 21 μm-thick one-type esterimide wire. Furnace temperature is 250 ° C
The coating was baked to form a fused layer of 8 μm to prepare a self-fusing electric wire.

Create a helical coil from the obtained self-fusing electric wire
Table 1 shows the results of fusion bonding at 220 ° C for 3 minutes and measurement of the fixing force.
Shown in

Comparative Example 2 The phenoxy resin of Comparative Example 1 was replaced with Denkabutyral # 3000.
The procedure was the same as in Comparative Example 1 except that K (Electrochemical Industry) was used.

Comparative Example 3 The same procedure as in Comparative Example 1 was carried out except that the phenoxy resin of Comparative Example 1 was changed to copolymerized nylon diamide T-251 (Daicel Chemical), and the solvent was changed from NM2P to m-cresol.

[Example 1] A, D, C, A Vinyl Hole AC # 3M (Eiwa Chemical Co., Ltd.) was added to the fusion coating of Comparative Example 1 in an amount of 5 PHR, and a self-fusing electric wire was prepared in the same manner as in Comparative Example 1. Table 1 shows the results of measuring the fixing force.

Example 2 D, P, T Cellular D (Eiwa Chemical Co., Ltd.) was added to the fusion coating of Comparative Example 1 in an amount of 5 PHR, and a self-fused electric wire was prepared in the same manner as in Comparative Example 1. Table 1 shows the results of measuring the fixing force.

Example 3 The procedure of Example 1 was repeated, except that A, D, C, and A vinyl holes AC # 3M in Example 1 were changed to O, B, S, and H neocervone N1000 #.

Example 4 Example 1 was repeated except that the phenoxy resin of Example 1 was changed to a butyral resin denkabutyral # 3000K (Denki Kagaku Kogyo).
The same was done.

[Example 5] The procedure of Example 1 was repeated, except that the phenoxy resin of Example 1 was changed to a polyamide resin.

Example 6 The procedure of Example 1 was repeated, except that the amounts of A, D, C, and A in Example 1 were changed to 0.1 PHR.

Example 7 The procedure of Example 1 was repeated, except that the amounts of A, D, C, and A were changed to 1 PHR.

Example 8 Example 8 was carried out in the same manner as in Example 1 except that the amounts of A, D, C, and A were changed to 10 PHR.

Example 9 The procedure of Example 1 was repeated, except that the amounts of A, D, C and A in Example 1 were changed to 20 PHR.

Example 10 Example 10 was carried out in the same manner as in Example 1 except that the amounts of A, D, C, and A were changed to 50 PHR.

Comparative Example 4 The procedure of Example 1 was repeated, except that the amounts of A, D, C, and A in Example 1 were changed to 100 PHR.

Example 11 The procedure of Example 1 was repeated, except that the thickness of the fused layer in Example 1 was changed to 6 μm.

Example 12 Example 12 was performed in the same manner as Example 1 except that the thickness of the fusion layer was changed to 3 μm.

 Table 1 shows the experimental results.

As is clear from Table 1, it can be seen that the use of the foaming agent improves the fixing force and makes it possible to reduce the thickness of the fusion layer to 1/3.

[Effects of the Invention] As described above, the use of the self-fusible electric wire of the present invention has an advantage that the fusion force is improved by foaming of the fusion layer and the fusion layer can be thinned. .

[Brief description of the drawings]

 FIG. 1 is a sectional view of the self-fusing insulated wire of the present invention. 1: conductor 2: insulating film 3: self-fusion layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-52-66545 (JP, A) JP-A-60-161466 (JP, A) JP-A-60-243172 (JP, A) JP-A 62-65 117216 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01B 7/02 C09D 5/25 H01B 3/30 H01F 5/06

Claims (5)

(57) [Claims] 1. A self-fusing insulated wire, wherein a fusion layer foamed at the time of fusion is formed on a metal conductor via an insulating layer. 2. The self-fusing insulated wire according to claim 1, wherein the fusion layer contains a foaming agent. 3. The self-fusing insulated wire according to claim 1, wherein the amount of the foaming agent is 0.1 to 50 parts by weight based on 100 parts by weight of the resin of the fusion layer. 4. The self-fusing insulated wire according to claim 1, wherein the resin of the fusion layer contains butyral resin or phenoxy resin as a main component. 5. A coil wherein the self-fusing insulated wire according to claim 1 is subjected to a winding process and then a fusion layer is foamed.