JPH0644416B2 - Self-bonding magnet wire - Google Patents

Description

The present invention relates to a self-bonding magnet wire. More specifically, a self-bonding magnet suitable for winding a self-supporting coil, such as a small flat motor coil (hereinafter abbreviated as flat coil) used for driving a VTR or a floppy disk, which requires dimensional accuracy. Regarding wires.

[Conventional technology]

A self-fusing magnet wire that is baked by applying a fusion coating on an electric conductor through an insulating coating, melts or swells the fusion coating by heating or treating with a solvent after winding the coil. Since it can be bonded and solidified, it is possible to relatively easily make a self-supporting coil, and it is widely used for a coil winding having a complicated shape such as a flat coil. Self-fusing magnet wires are roughly classified into two types, hot air bonding type and solvent bonding type, depending on the method of bonding between the lines. In general, in the hot air bonding type in which the fusion film is melt-bonded by heating, there is a limit to the temperature of the hot air blown onto the wire, and the thermal softening temperature is limited to a low melting point resin fusion film of about 120 to 150 ° C. Therefore, the heat resistance is low. On the other hand, the solvent adhesive type, in which the fusion film of the self-adhesive magnet wire is dissolved and swelled with an alcohol solvent such as methanol or ethanol, and then adhered, a high melting point material can be used to produce a coil with good heat resistance. It is possible to

In recent years, due to the introduction of a fully automatic coil winding machine for the flat coil alignment winding, the self-bonding magnet wire has a heat-resistant property, and the finished dimension has less tolerance. There is a growing demand for a winding property that is excellent in alignment and has high dimensional accuracy.

The conventional solvent-bonding self-fusing magnet wire fusing paint is, for example, bisphenol A-based diglycidyl ether type epoxy resin added to alcohol-soluble polyamide resin and dissolved in an organic solvent containing cresol as a main component. The ones that are done are often used.

[Problems to be Solved by the Invention]

However, in the case of self-fusing magnet wire coated and baked with this conventional fusing paint on the conductor through an insulating film, when a flat coil is aligned and wound while applying alcohol using a fully automatic winding machine. Since the fusion coating has too good alcohol solubility, even if the self-bonding magnet wire has little variation in the finished outer diameter, part of the fusion coating is scraped off at the alcohol application part, so The outer diameter was non-uniform, and coils were randomly wound, so the coil alignment rate was poor.

Further, the fusion coating swelled and dissolved by alcohol is apt to adhere to the jig of the above-mentioned winding machine, and there is a drawback that the jig is contaminated. Further, the coil immediately after winding has a drawback that it easily deforms because a large amount of alcohol is contained in the fusion coating, and it takes time for this alcohol to volatilize from the inside of the coil to obtain a strong bond. there were.

In order to solve the above-mentioned drawbacks, a fusion-bonding paint consisting of three components in which a bisphenol A-based diglycidyl ether type epoxy resin and a block isocyanate compound are added to an alcohol-soluble polyamide resin has been proposed, which causes a problem of jig contamination of a winding machine. Was settled. However, even when this improved self-bonding magnet wire was used, the winding property was still poor and the coil alignment rate was low.
The coil immediately after winding contains a large amount of alcohol and is swollen, so it is easily deformed by external force.
There is a problem that the coil size changes after the alcohol is volatilized.

In particular, after the coil winding, if a heat treatment process such as soldering this coil to the substrate using paste solder is performed in the next step, the coil will be further thermally deformed, and it will be significantly deviated from the dimension immediately after winding. Was a challenge.

The present invention was made in order to solve the problems of the above-mentioned prior art, and its object is to have a good winding property and a good coil alignment rate when wound on a flat coil, and to further prevent thermal deformation. It is an object of the present invention to provide a self-fusion-bonding magnet wire that can obtain a coil that does not occur.

[Means for Solving the Problems]

In order to achieve the above object, the present invention uses a bisphenol A-based diglycidyl ether type epoxy resin having an average molecular weight of 30,000 to 50,000 (hereinafter abbreviated as an epoxy resin having a film forming function) having a film forming function as an organic solvent. The molten fusion paint is applied and baked directly on the conductor or through another insulating coating to form a first fusion coating that is insoluble in alcohol and melts by heat, and alcohol is further provided on the outer periphery of the first fusion coating. Molecular weight of 900-4,00 in 100 parts by weight of soluble polyamide resin
0 to 50 parts by weight of a bisphenol A-based diglycidyl ether type epoxy resin and 5 to 15 parts by weight of a blocked isocyanate compound are added, and a fusion paint prepared by dissolving this in an organic solvent is applied and baked to make an alcohol-soluble second fusion bond. It is a self-bonding magnet wire with a coating.

The epoxy resin having a coating film forming function that forms the first fusion-bonding film of the present invention is an epoxy resin having an average molecular weight of 30,000 to 50,000, and specific examples include Fenotote YP50 (trade name of Toto Kasei Co., Ltd.) and Epicron EXA192 (Dainippon Nihon. Ink Chemical Co., Ltd. product name) and the like.

The alcohol-soluble polyamide resin, which is the main component of the second fusion coating of the present invention, has a melting temperature of 180 ° C. or higher, for example, Ultramid 1C (Germany B) in consideration of the heat resistance of the coil.
It is desirable to use a high melting point material such as ASF's product name), Amilan CM4000, and CM4001 (Toray's product name). A bisphenol A-based diglycidyl ether type epoxy resin having a molecular weight of 900 to 4,000 (hereinafter abbreviated as an epoxy resin) is a resin added for improving the touch-drying property of a coating film and adjusting the viscosity of a fusion coating composition. Examples include Epotote YD-011, YD-014, YD-017 (trade name of Tohto Kasei Co., Ltd.), Epicoat 1001, 1004, 1007 (trade name of Yuka Shell Epoxy Co., Ltd.) and the like. The reason for limiting the molecular weight to 900 to 4,000 is that if the molecular weight exceeds 4,000, the compatibility with the alcohol-soluble polyamide resin deteriorates, and if the molecular weight is less than 900, the shape of the epoxy resin becomes semi-solid. This deteriorates the dryness to the touch and reduces the releasability from the coil winding jig.

The blocked isocyanate compound is a cross-linking agent for the epoxy resin, and specific examples thereof include Millionate MS-50 and Coronate AP Stable (trade name of Nippon Polyurethane Company).

The reason why the addition amount of the epoxy resin to the alcohol-soluble polyamide resin is limited to 10 to 50 parts by weight and the addition amount of the blocked isocyanate compound to 5 to 15 parts by weight is that in these resins, if the addition amount is less than the limited weight part, This is because no effect is observed, and when the amount exceeds the limited weight part, the fusion property of the fusion coating is significantly impaired.

[Work]

A fusion-bonding coating composed of the alcohol-soluble polyamide resin as a main component, and an epoxy resin and a blocked isocyanate compound added thereto, which is a three-component fusion coating composition, is a low-molecular-chain epoxy resin in a matrix of the alcohol-soluble polyamide resin by coating and baking. Are uniformly distributed at a constant ratio, and the hydroxyl group in the main chain of the epoxy resin reacts with the blocked isocyanate compound, so that cross-linking with an interpenetrating network structure is formed. That is, by using the blocked isocyanate compound as a cross-linking agent, it is possible to control the magnitude of the intermolecular cross-linking density. Therefore, the addition of the blocked isocyanate compound acts to suppress the swelling degree or the solubility of the second fusion-bonding film in alcohol to an appropriate value.

Generally, in an aligned winding of a flat coil by applying alcohol, if the swelling degree or the solubility of the fusion coating is too good for alcohol, a part of the swelled or dissolved fusion coating adheres to the winding jig, or Since the outer diameter of the fusion coating also tends to fluctuate, the coil alignment rate decreases. On the contrary, when the swelling degree or the solubility in alcohol is poor, the adhesion between the wires becomes insufficient and the winding cannot be performed. Therefore, the second fusion-bonding film imparts an initial adhesive force required for bonding between coil wires in an aligned winding of a flat coil formed by applying alcohol, and further reduces dirt on the winding jig, Also increase the alignment rate.

On the other hand, the first fusion coating is made of an epoxy resin fusion coating having a coating forming function. Since this fusion coating is insoluble in alcohol, it swells in the step of applying alcohol and winding the flat coil. Although it does not melt and does not contribute to initial adhesion, it melts in the heat treatment for soldering the coil to the printed circuit board using the paste solder in the next step, and the wire between the coils is firmly fused.

In the fusion coating of the present invention, a first fusion coating which is insoluble in alcohol and melts by heat and a second fusion coating which is soluble in alcohol are used instead of the conventional alcohol-soluble fusion coating,
It suffices that the total thickness of the first fusion coating and the second fusion coating is equal to the thickness of the conventional fusion coating. Therefore, when viewed from the whole of the fusion coating, the melt that swells and dissolves in alcohol. Since the adhesion coating is reduced, fluctuations in the outer diameter of the fusion adhesion coating during alcohol application in the flat coil winding process are reduced,
The coil alignment rate increases. Further, since the alcohol content in the wound coil is also reduced, it is possible to suppress the dimensional change of the coil after alcohol volatilization or heat treatment.

〔Example〕

The contents of the present invention will be described below with reference to Examples and Comparative Examples.

Preparation of Fusion Coatings Table 1 is a composition table of the fusion coatings of Examples 1-5 and Comparative Examples 1-3. YP50CS25B (Toto Kasei Co., Ltd. product name), which is a 25% solution of an epoxy resin having a film-forming function dissolved in an organic solvent, is diluted with a mixed solvent of m-cresol and xylol to give a fusing coating having a concentration of 15%. Example-I) was prepared. In addition, the alcohol-soluble polyamide resin Ultramid 1C (trade name of BASF, Germany) is added to Epicoat 1007 (trade name of Yuka Shell Epoxy Co., Ltd.), which is a bisphenol A-based diglycidyl ether type epoxy resin.
And a blocked isocyanate compound, Millionate
MS-50 (trade name of Nippon Polyurethane Company) was added in the composition shown in Table I and dissolved in a mixed solvent of m-cresol and xylol to prepare a fusion coating composition (Example-II) having a concentration of 14%.

Further, as the fusion-bonding paint of the comparative example, the fusion-bonding paint having the composition shown in Table I and a concentration of 14% was prepared in the same manner as in Example-II (Comparative Example-I.
I) was prepared.

Production of Self-Fusing Magnet Wire The production of the self-fusing magnet wire of Examples and Comparative Examples will be described with reference to FIG.

Examples 1 to 5 As the conductor 1, first, a fusion-bonding coating (Example-I) made of an epoxy resin having a film-forming function is finished on a copper wire having a conductor diameter of 0.220 mm with a 6 μm-thick polyester insulating film 2. The first fusion-bonding film 3a is formed by coating and baking so that the outer diameter is 0.240 mm, and then a fusion-coating material containing alcohol-soluble polyamide resin as a main component (Example-II) is used to finish the outer diameter. The second fusion coating 3b was formed by coating and baking so as to have a thickness of 0.248 mm, and as the fusion coating 3, a self-fusion magnet wire composed of the first fusion coating 3a and the second fusion coating 3b was manufactured. (The thickness ratio between the first fusion coating and the second fusion coating is 5: 5 in the present embodiment, but the ratio is 4: 6 to.
It may be in the range of 6: 4. ) Comparative Examples 1 to 3 As a conductor, a coating composition (Comparative Example-II) containing alcohol-soluble polyamide resin as a main component was applied onto a copper wire having a conductor diameter of 0.220 mm through a polyester insulating film having a thickness of 6 μm to finish the outer diameter. Of 0.248 mm was applied and baked to manufacture a self-bonding magnet wire. These self-bonding magnet wires were tested based on JIS C 3003 "Test method for enamel copper wire and enamel aluminum wire", and the results are shown in Table II.

Flat coil winding and characteristics Using a single-axis fully automatic winding machine, while applying ethanol to the self-bonding magnet wire of the example and the comparative example, the flat coil was wound at a rotation speed of 1,500 rpm. . For each example, 100 flat coils were wound and tested for coil alignment rate, jig contamination, coil thermal deformation, etc., and the results are shown in Table III. The coil alignment rate was calculated by the following equation.

In addition, the thermal deformation test was carried out at a thickness of 200 ° C x 1 immediately after winding the coil.
The thickness after 0 minute heat treatment is measured with a micrometer, and the value immediately after winding is subtracted from the value after heat treatment. When the value is 0 or-, it is judged that there is no coil swelling (no thermal deformation). When the value was +, it was determined that there was swelling of the coil (there was thermal deformation).

[Effects of the Invention] As is clear from the characteristics shown in Table III, the self-bonding magnet wire of the present invention has a better alignment rate and less jig contamination than the conventional self-bonding magnet wire. ,
Also, a coil with less thermal deformation can be obtained. This is because the self-bonding magnet wire of the present invention has a first fusion-bonding film that is insoluble in alcohol composed of an epoxy resin having a film-forming function and melts by heat and an alcohol-soluble polyamide resin containing an alcohol-soluble polyamide resin as a main component. This is because it has a double-structured fusion film composed of the second fusion film. Further, the second fusion coating contributes to the initial adhesion between the wires in the winding by the application of alcohol, while the first fusion coating does not swell or dissolve in the alcohol, but is melted by the heat treatment after the winding and is then melted. Strengthen the bond between them. Since only the second fusion coating is swollen or dissolved by alcohol, the outer diameter variation of the fusion coating during application of alcohol is reduced, the coil alignment rate and the winding property are extremely good, and the productivity in flat coil production is improved. Greatly improved.

[Brief description of drawings]

FIG. 1 is a transverse sectional view showing an embodiment of the self-bonding magnet wire of the present invention. 1 ... conductor, 2 ... insulating film, 3 ... fusion film, 3a ...
First fusion coating, 3b ... Second fusion coating.

 ─────────────────────────────────────────────────── --- Continued from the front page (56) References JP-A 48-31477 (JP, A) JP-A 50-144089 (JP, A) JP-A 51-101520 (JP, A) JP-A 59- 20916 (JP, A) JP 60-223868 (JP, A) JP 2-142018 (JP, A) JP 3-62412 (JP, A) Actual development Sho 50-34786 (JP, U) Actually open 50-34787 (JP, U) Actually open 50-43876 (JP, U) Special public 45-7893 (JP, B1) Actual public 50-29735 (JP, Y1)

Claims (1)

[Claims] 1. An average molecular weight of 30,000 to have a film forming function.
50,000 bisphenol A-based diglycidyl ether type epoxy resin dissolved in organic solvent is applied and baked on the conductor directly or through another insulating film, and 100 parts by weight of alcohol-soluble polyamide resin is further applied to the outer periphery. 10 to 50 parts by weight of a bisphenol A-based diglycidyl ether type epoxy resin having a molecular weight of 900 to 4,000 and 5 to 15 parts by weight of a blocked isocyanate compound are added, and a fusion paint prepared by dissolving this in an organic solvent is applied and baked. Self-bonding magnet wire that does.