JPS58163107A - 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 producing an insulated core wire coated with a polyamide resin.

Conventionally, to manufacture insulated 4-wire wires such as magnet wires, an insulating paint made by dissolving resin in an organic solvent is usually applied to the conductor.
It is dried and solidified. At this time, in order to make it easier to coat the conductor with insulating paint, the viscosity is adjusted using a vertical solvent, but due to the toxicity of the solvent and the inability to recover the solvent sufficiently, From the viewpoint of improving the working environment and saving resources, there is a strong desire for a method of manufacturing insulated d-wires that does not use solvents.

In order to meet these demands, a method of bath-melting thermoplastic resin such as polyamide thread resin onto the conductor by extrusion molding may be considered, but simply coating the conductor with thermoplastic resin will not improve wear resistance or other properties. It is impossible to obtain an insulated wire that passes JIS standards and can be used as a magnet wire due to its inferior mechanical strength and heat deterioration resistance, and even if it can be used, it can only be used in extremely limited equipment. .

The object of the present invention is to produce an insulated wire that does not use a solvent when coating a conductor with a polyamide resin, does not have the above-mentioned drawbacks, and has sufficient properties to be used as a magnet wire. is to provide.

In order to achieve the above-mentioned object, the present inventors have conducted extensive research on a method for manufacturing insulated wires that does not use solvents, and as a result, they first coated a linear conductor with polyamide resin, and then exposed this resin coating layer to radiation. The gel fraction of the coating layer is 20 after irradiation.
By cross-linking the wire to a temperature of 10% or more, we were able to obtain properties similar to those of an insulated wire. However, as a result of further investigation, it was found that unsaturated monomers were added to the surface of the polyamide resin coating layer before irradiating the polyamide resin coating layer with radiation. By coating, the crosslinking density of the coating layer increases, heat resistance is improved, the bonding force of crosslinking is strengthened, thermal stability can be improved, and mechanical strength can also be improved. Thus, it has been discovered that the above-mentioned drawbacks can be eliminated, and the present invention has been achieved.

In the present invention, a linear conductor is coated with a fat polyamide resin, a polyfunctional unsaturated monomer is applied to the surface of the resin coating, and the coating layer is irradiated with radiation. The above objective is achieved by crosslinking until the gel fraction of the layer is above 20%.

Examples of the polyamide resin used in the present invention include nylon 6 (polycabramide), nylon 6/6 (polyhexamethylene aziboamide), nylon 6/10 (polyhexamethylene sebaamide), and nylon 11 (polyhexamethylene aziboamide). homopolymers such as undecaneamide), nylon 2 (bo-11 lauramide), and nylon 6/nylon 6.6/nylon 6.10 (10/40/fiO %) copolymers, ε-caprolactam/nylon 6 - 6#A/Nylon 6.1O salt (10/40 150% by weight) It is a binary or ternary copolymer such as a coelectric polymer. If necessary, various additives such as stabilizers such as anti-aging agents, pigments, fillers such as glass fibers, etc. can be added to the polyamide resin used in the present invention. Coating polyamide resin onto a linear conductor without using a solvent can be easily done by applying it in a heated molten state, or by a normal thermoplastic resin molding method such as extrusion molding. be able to.

The polyfunctional unsaturated monomers used in the present invention are divinylbenzene, mono-, di-, and tri-ethylene glycol diacrylates.

Mono-, di-, tri-, and tetra-ethylene glycol dimethacrylates, vinyl acrylate, vinyl methacrylate, allyl acrylate, allyl methacrylate, divinyl ether of diethylene glycol, diallyl maleate, diallyl itaconate, diallylbenzene phosphonate, tri- Allyl phosphate, triallyl cyanurate, triallyl isocyanurate, glycerin trimethacrylate, tris(g-hydroxyethyl)isocyanuric acid acrylic acid ester tris(2
- polyfunctional unsaturated monomers selected from the group consisting of methacrylic esters of (hydroxyethyl) isocyanuric acid, dicyclopentenyl acrylate, dicyclopentenyloxy-ethyl acrylate, their corresponding close homologues and mixtures thereof. It is. The polyfunctional unsaturated monomer does not need to be kneaded into the polyamide resin, and exhibits sufficient properties simply by being applied to the surface of the polyamide resin, which is advantageous in terms of manufacturing process and economy. To apply the polyfunctional monomer, use a sprayer to spray the polyfunctional monomer, or place the polyfunctional monomer in cypress wood or the like and pass the polyamide resin-coated wire through it by dipping it. method etc. can be used.

Examples of the radiation that crosslinks the coating layer after coating the polyfunctional monomer include electron beams, alpha rays, and beta rays.

Although ultraviolet rays are used, high-energy electron beams generated from electron accelerators that can easily obtain a large capacity and speed up the irradiation operation on the applied adhesive composition, and relatively easily The resulting UV radiation is particularly preferred.

The irradiation dose of the radiation irradiated to the resin coating layer is 5 to fl OMrad when using an electron beam, which is a preferable radiation source.
It is desirable that the range is 20, and a particularly preferable range is 20.
~40 Mrad. The reason for this is that the radiation monitor is 5 M
If it is less than rad, the crosslinking is insufficient and the gel fraction does not reach 20%, so the magnet wire insulation 'I!
This is because it is difficult to obtain the necessary characteristics as a II beam, and even if irradiation is performed in a larger amount than fl O'Mrad, the effect will not increase, but rather a decomposition reaction will occur and the characteristics will tend to deteriorate. "Gel fraction" here refers to m-
This is the weight ratio of the insoluble residue to the total coating layer when heated in cresol. Also, when using ultraviolet light,
Using a high-pressure mercury lamp, the distance between the electric wire and the mercury lamp is 10c.
By setting rn and performing irradiation for about 0.4 to 10 seconds, crosslinking can be carried out until the gel fraction reaches 20% or more.

1. In the case of ultraviolet rays, 0.5 to 5% by weight of the polyfunctional unsaturated monomer used, for example, benzophenone or its derivatives, benzoin ether,
It is necessary to use a photoinitiator such as benzyl, benzyl dimethyl ketal, or tetramethylthiuram monosulfide. It is also possible to add and blend a photoinitiator into the polyamide resin, but in this case, since the resin has a high melting point, the photoinitiator may decompose during kneading, and the desired effect may not be achieved. This is not preferable because it will not be possible to obtain it.

Furthermore, radiation and irradiation of glands are sometimes not limited to the atmosphere;
For example, it can be carried out in any atmosphere, such as an atmosphere that does not contain oxygen or an atmosphere that contains oxygen such as air.

The polyfunctional unsaturated monomers applied to the surface of the polyamide resin coating j- not only react with each other, but also react with free radicals generated during the crosslinking process of the polyamide resin. It is possible to react with When polyfunctional monomers coexist, a stronger crosslinked product is produced than when polyamide resin is used alone, and therefore it has better heat resistance than when radiation crosslinking alone is used without coating polyfunctional unsaturated monomers. It is believed that this provides good physical properties and mechanical properties. When comparing the heat resistance of insulated wires for magnet wires with respect to the increased heat softening temperature, which is important as a measure of their heat resistance, those with only radiation crosslinking and not coated with a polyfunctional monomer are 2.
While the temperature is about 60°C, the one coated with a polyfunctional monomer shows a remarkable improvement to about aOO″C.

In producing an insulated wire according to the present invention, each step of (coating with at polyamide resin, coating with (bl polyfunctional monomer) and irradiation with radiation is carried out continuously using a running linear conductor. The coating layer is heated to a temperature higher than the melting point of the resin in the heating process and melts, becoming liquid in the same way as when applying conventional paints that use solvents. If this is not done in the correct condition, unevenness or dripping of the resin coating layer will occur.In addition, winding up on a bobbin etc. after coating the polyfunctional monomer may cause uneven coating and change in properties. So I don't like it very much.

Therefore, it is most preferable that the steps of resin coating, monomer application, and radiation irradiation are performed continuously. In conventional manufacturing methods that use solvents, the amount of one coating in the coating and baking process for film formation is limited in order to volatilize the solvent and reaction products.
When using a linear conductor of This is also an advantage of the present invention. The insulated wire obtained by the method of the present invention has a thermal softening temperature, which is a measure of its heat resistance, and mechanical strength, which are almost the same as those of an insulated wire produced by the conventional method using a solvent-based paint.

Next, the present invention will be explained with reference to Examples and Comparative Examples. Measurement of the properties (flexibility, chemical resistance, abrasion resistance, insulation value w x voltage, crazing resistance) of the insulated wires obtained in these examples was carried out in accordance with the test method specified in HJI8-C8210. . Measurement of thermal softening temperature of insulated wires is JI day-08
18.1.l paternal difference method (2) of the test method prescribed in 008
It was carried out according to the heating method (the load was 800), that is, two test pieces of length l0CII were taken from the same winding frame, stacked at right angles, placed on a flat plate, and placed on the overlapped part. 5
A weight of 001 was placed on the test piece, the test piece was placed in a constant temperature oven, and an AC voltage of 50 to f30 Hz with a waveform close to a sine wave was applied between the conductors of the test piece.
The temperature was increased at a rate of 100 min and the temperature at which a short circuit occurred was measured.

The gel fraction was measured by peeling off the resin film from the insulated wire and heating the film in m-cresol at 90°C to determine the weight % of the insoluble residue.

Example 1; Nylon 6 tatami 10 resin (Toyo Rayon Co., Ltd.) was extruded onto a 0.85 mm φ copper wire at an extrusion temperature of 250'C using a crosshead using an Omuφ extruder with a nylon screw fixing die nipple. Manufactured by, product name: Amilan CM2O0
1, melting point 2]7°C) was extruded to form a coating film with a thickness of 28 to 32 μm on a copper wire. After spraying triallyl cyanurate (manufactured by Nippon 1 Kasei Co., Ltd.) onto this coating film using a sprayer, the coated wire was irradiated with an electron beam at 85 Mrad to obtain an insulated wire. In addition, the manufacturing speed is 200m
/ minute.

(11) Comparative Example] An insulated wire was obtained in the same manner as in Example 1, except that triallyl cyanurate was not sprayed onto the resin-coated wire.

Comparative Example 2 An insulated wire was obtained in the same manner as in Example 1, except that the resin-coated wire was not sprayed with triallyl cyanurate or irradiated with an electron beam, and the coated wire obtained by squeezing with a die was immediately cooled with water. Ta.

Example 2 Tris(
An insulated wire was obtained under the same conditions as in Example 1, except that acrylic acid ester of 2-hydroxyethyl)incyanuric acid (manufactured by Hitachi Chemical Co., Ltd.) was used.

Example 8 Trimethylolpropane trimethacrylate (Shin Nakamura Chemical Co., Ltd.) was used instead of triallyl cyanurate on the resin coating line.
An insulated wire was obtained under the same conditions as in Example 1, except that #) was used.

21 Example 4 Insulation was carried out under the same conditions as in Example, except that diethylene glycol diacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) was used instead of triallyl cyanurate for the resin-coated wire.
I got a blur.

Example 5 2.2' instead of triallyl cyanurate on the resin coating line
An insulated wire was obtained under the same conditions as in Example except that -bis(4-methacryloxy-jethoxyphenyl)propane (manufactured by Shin-Nakamura Chemical Industries, Ltd.) was used.

Example 6 Insulation was carried out under the same conditions as in Example except that nylon 6 resin (manufactured by Toyo Rayon Co., Ltd., trade name: Amilan (M1021, melting point 215'C) was used instead of nylon 6/10 resin). Got the wire.

Example 7 Nylon 6.6 resin (manufactured by Toyo Rayon Co., Ltd., trade name Nimiran CM8001,
An insulated wire was obtained under the same conditions as in Example 1, except that the extrusion temperature was changed to 270°C (melting point: 259°C) and the extrusion temperature was changed to 270°C.

Example 8 Nylon 6/10 resin (manufactured by Toyo Rayon Co., Ltd.).

Product name: Amilan C'M2O0], melting point 2]7°C) was heated and melted at 240 ''C, a copper wire with a diameter of 0.851111 was passed through the molten resin, and the outlet from the molten resin was passed through the molten resin. A coating film with a thickness of 28 to 82μ was formed on the copper wire by squeezing with a die.Benzyl methyl ketal (Wamoto Jun After spraying a solution containing 8M bond part (manufactured by Yakuhin Co., Ltd.) using a sprayer, the input density was 8 on this painted line.
Using a device that uses two 0W high-pressure mercury lamps (2KW) to uniformly emit ultraviolet rays, irradiate ultraviolet rays at a linear velocity of 20rnZ with a distance between the source and the '1 line of 10GII+. After that, I rolled it up.

Regarding the insulated wires obtained in the above examples and comparative examples, gel fraction, thermal softening temperature, and wire characteristics (flexibility, chemical resistance, abrasion resistance, dielectric breakdown voltage) were determined.

Crazing resistance) was measured and the results are shown in Table 1.

The following can be seen from the table.

Regarding the thermal softening temperature, the temperature is 300 to
310°C, and is therefore equivalent to or higher than that of insulated wire manufactured using conventional solvent-based paints. The wire crosslinked by radiation irradiation (Comparative Example 1) has a temperature of 280°C, which is lower than the insulated wire manufactured using conventional solvent-type paint, which is problematic. In addition, the temperature was even lower at 190° C. for one without crosslinking by electron beam irradiation (Comparative Example 2), which did not satisfy the characteristics as an insulated straight line for magnet wires.

Regarding the gel fraction, it is almost the same in the range of 90 to 98% even if the type of polyamide resin and the type of polyfunctional unsaturated spraying material are changed, and it is almost the same even if the type of polyamide resin and the type of polyfunctional unsaturated monomer are changed. This value is approximately the same as 90% of the crosslinking without crosslinking by electron beam irradiation (Comparative Example 1). Crosslinking was carried out by radiation irradiation.17 The results are shown in Table 2.

Of course, in the case where it was not present (Comparative Example 2), it was 0%.

The characteristics of the electric wire are almost the same even if the type of polyamide resin, the type of polyfunctional unsaturated monomer, or the type of radiation is changed;
Those that satisfy the characteristics as a beam but are only cross-linked with electron beams (comparative example)) and those that were not cross-linked with radiation (comparative examples)
Comparative Example 2) does not satisfy the characteristics at all as an insulated straight line for magnet wire. Although the gel fraction of the polyfunctional unsaturated monomer sprayed and then crosslinked by electron beam irradiation or ultraviolet irradiation was almost the same as that of Comparative Example 1, which was only electron beam crosslinked, High mechanical strength such as heat softening temperature and wear resistance. This is thought to be because the former has a more robust three-dimensional structure than the latter.

Example 9 Insulated wires were obtained under the same conditions as in Example 1, except that the electron beam irradiation dose was changed as shown in Table 2. The gel fraction and thermal softening temperature of this insulated wire are considered to be (] 8 ).

From Table 2, Table 2 shows that when the electron beam irradiation dose is OMrad, the gel fraction is 0% and the thermal softening temperature is as low as 200°C, and when the irradiation dose is a Mrad, the gel fraction is 15%. The thermal softening temperature is as low as 2]0''C, indicating that the irradiation dose is insufficient.As the irradiation dose approaches ]OMrad, the irradiation dose increases until the gel fraction and heat approach 6°Mrad. Both softening temperatures are appropriate.Irradiation I@
When the fiber becomes thicker and becomes 60 Mrad, both the gel fraction and the heat softening temperature decrease slightly. This will cause excessive hardening, and the patent applicant: Furukawa Electric Co., Ltd. Procedural Amendment June 16, 1982 1, Case Description 1982 Patent Application No. 4.5508 2, Title of Invention: Insulated Wire Manufacturing method 3, relationship with the case of the person making the amendment Patent applicant (529) Furukawa Electric Co., Ltd. Telephone number (581) 2241 (representative) 5゜6, Subject of amendment Detailed explanation of the invention in the specification Column 7 , Contents of the amendment (as shown in the attached sheet) ■ Correct ``Amilan (Ml) to ``Amilan OMJ'' on page 18, line 14 of the specification.

2 “Pencil methyl ketal (
manufactured by Wako Pure Chemical Industries, Ltd.)” and “benzyl dimethyl ketal (manufactured by Wako Pure Chemical Industries, Ltd.)”.
Corrected to ``Made by Chiba Geigy, Japan.''

Representative Patent Attorney: Hide Sugimura 1 other person (g・5

Claims (1)

[Scope of Claims] L In manufacturing an insulated wire temporarily covered with a polyamide resin, fal the polyamide resin is coated on a linear conductor, fbl a polyfunctional unsaturated layer is coated on the surface of the resin coating layer. A method for producing an insulated wire, comprising applying a monomer, and irradiating the coating layer with radiation to crosslink the coating layer until the gel fraction of the coating layer becomes 20% or more. The manufacturing method according to claim 1, in which an electron beam is used as the λ radiation. & The method according to claim 1, in which a polyfunctional unsaturated monomer to which 0.5 to 5% by weight of a photoinitiator is added is used as a polyfunctional unsaturated monomer, and ultraviolet rays are used as radiation. Production method.