JPH0562406B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a composite enamelled wire.
More specifically, the present invention relates to a composite enameled wire comprising a brazing polyesterimide layer and a polyurethane layer. [Prior Art] A polyurethane enameled wire is an insulated wire made by coating and baking a polyurethane paint on a conductor. In this polyurethane enameled wire, the enamel film molecules are thermally dissociated at a temperature of 200°C or higher, and the thermally dissociated product exhibits a flux effect. Therefore, the polyurethane enamelled wire can be soldered directly onto the enameled wire without peeling off the enamel film. This property is called brazing property, and this polyurethane enameled wire is the most representative enameled wire having this brazing property. In addition to its brazing properties, polyurethane enameled wire has excellent coloring properties and workability for applying and baking thin enameled wires, so it is used as coils for electrical equipment such as communication equipment and home appliances where thin enameled wires are mainly used. Widely used. On the other hand, such polyurethane enamelled wires are being used in electrical equipment such as communication equipment and home appliances at higher frequencies in order to improve performance. However, when polyurethane enameled wire is applied to high-frequency electrical equipment coils, such as deflection coils for high-resolution displays and coils for switching regulator transformers, the disadvantage is that its service life is short. Examples of such enameled wires having excellent high-frequency breakdown voltage characteristics include polyamide-imide enameled wires, polyimide enamel wires, and polyester enameled wires. However, these enamelled wires essentially do not have brazing properties, and the disadvantage is that they require many man-hours for terminal treatment after coil winding. On the other hand, as enameled wires having brazing properties other than polyurethane enameled wires, brazing oil-based enameled wires, brazing polyesterimide enameled wires, etc. are produced in small quantities. For example, an insulated wire disclosed in Japanese Patent Application Laid-Open No. 49-97288 is known as a brazing polyester imide enameled wire. This soldering polyesterimide enameled wire has a soldering polyesterimide layer synthesized from a specific material directly above the conductor, and a polyimide insulation paint or polyamideimide insulation paint with excellent heat resistance is applied and baked on the top layer. It is what it is. However, the problem with this product is that the soldering properties are deteriorated by the polyimide layer or polyamide-imide layer. Furthermore, Japanese Patent Application Laid-Open No. 52-104780 describes a process of applying unsaturated urethane varnish on a conducting wire and curing it by irradiating it with ultraviolet rays or electron beams to form a base-treated conducting wire; A method for manufacturing a solderable enamelled wire has been proposed, which comprises the steps of coating the above-mentioned base-treated conductive wire and curing it by irradiating it with ultraviolet rays or electron beams.
However, this solderable enameled wire requires a curing process by irradiating it with ultraviolet rays or electron beams, and since it is a resin that hardens by irradiating ultraviolet rays or electron beams, it has many unsaturated bonds in its molecules, resulting in heat aging resistance. However, it has the disadvantage that its properties and high-frequency breakdown voltage characteristics are significantly inferior. In addition, JP-A No. 54-90588 discloses that thermoplastic linear polyurethane obtained from diol and diisocyanate is coated on a conductor with another insulator interposed therebetween for the purpose of improving refrigerant resistance.・
A self-bonding insulated wire characterized by baking has been proposed. However, since this self-bonding insulated wire is intended to improve refrigerant resistance and uses thermoplastic linear polyurethane as the upper layer, it has a disadvantage in that its brazing properties are poor. Furthermore, JP-A-56-6311 discloses a thermoplastic linear polyurethane obtained by reacting polyoxyalkylene glycol or a glycol component consisting of polyoxyalkylene glycol and alkylene glycol with an aromatic diisocyanate. A self-bonding insulated wire has been proposed, which is characterized by coating and baking a paint as a main component on a conductor via another insulator. However, since this insulated wire is a self-bonding insulated wire made by coating and baking a paint mainly composed of thermoplastic linear polyurethane, it has excellent refrigerant resistance and high temperature adhesive strength, but has poor solderability. The problem is that it is inferior. Furthermore, JP-A No. 59-99617 discloses a brominated polyhydroxy polyether resin with a molecular weight of 10,000 or more containing 10 to 55 wt% of bromine (100 wt%).
5 to 50wt of thermoplastic polyurethane resin
% is applied onto the conductor via a solderable polyesterimide film with a heat resistance class B or higher or a heat softening temperature of 300°C or higher. Self-bonding polyesterimide-based insulated wires have been proposed.
However, since this self-bonding polyesterimide insulated wire uses a bromine-containing blended polyurethane resin, there are drawbacks such as deterioration of the working environment due to brome, a decrease in heat resistance, and an increase in the cost of paint. [Problems to be Solved by the Invention] The present invention has been made based on the above points, and its purpose is to eliminate the drawbacks of the prior art described above, and to improve soldering properties and high frequency dielectric breakdown voltage resistance. The object of the present invention is to provide a composite enameled wire with excellent properties. [Means for Solving the Problems] The gist of the present invention is to provide a composite enameled wire in which a soldering polyesterimide layer is provided directly above a conductor, and a polyurethane layer is provided on the soldering polyesterimide layer, The composite enameled wire is characterized in that the brazing polyesterimide layer accounts for 5 to 20% of the total coating thickness, and the polyurethane layer consists of a non-linear polyurethane resin. In the present invention, the brazing polyesterimide layer is obtained by applying a brazing polyesterimide paint onto a conductor and baking it. Further, the polyurethane layer is obtained by applying and baking a polyurethane paint containing a non-linear polyurethane resin as a main component. In the present invention, the brazing polyesterimide layer provided directly on the conductor is set at 5 to 20% of the total film thickness because if the brazing polyesterimide layer is less than 5%, the brazing polyesterimide layer is too thin, so it is effective in improving high frequency breakdown voltage characteristics. This is because the temperature at which soldering is possible will rise rapidly if it is small and on the other hand 20% or more. That is, in the present invention, 5 to 20% of the total film thickness is applied directly on the conductor.
A solderable polyesterimide layer of 80% of the total film thickness is provided on the upper layer of the solderable polyesterimide layer.
By providing a polyurethane layer of ~95%, the brazing temperature is maintained at the same level as that of polyurethane, while the high-frequency dielectric breakdown voltage resistance, which is a drawback of polyurethane layers, is significantly improved. [Function] The composite enameled wire of the present invention significantly improves the high-frequency dielectric breakdown voltage resistance by providing a brazing polyester imide layer of 5 to 20% of the total film thickness directly on the conductor, and further improves its brazing properties. 80-95% of the total film thickness is a polyurethane layer on the polyesterimide layer.
By providing this, the brazing polyesterimide layer and the polyurethane layer are effectively eutecticly dissociated to exhibit excellent low-temperature brazing properties. [Example] Next, examples of the composite enamelled wire of the present invention and conventional comparative examples will be described using diagrams. First, the enamel wire paint used will be explained. (Polyester imide enamel wire paint with low adhesion properties) As the polyester imide enamel wire paint with low adhesion properties, FS-2 paint manufactured by Dainichiseika Kogyo Co., Ltd. was used. This FS-2 paint consists of 30% low-stick polyesterimide resin and the rest organic solvent such as cresol. (Polyurethane enamel wire paint) WD-4305 manufactured by Hitachi Chemical Co., Ltd. was used as the polyurethane enamel wire paint. This WD−
4305 was used. This WD-4305 paint is made up of 40% resin mainly consisting of polyol components and stabilized polyisocyanate, and the remainder made up of organic solvents such as cresol. The resin containing the polyol component and the stabilized polyisocyanate as main components becomes a non-linear polyurethane resin, that is, a thermosetting polyurethane resin, by baking. (Example 1) A brazing polyester imide enamel wire paint is applied and baked on a conductor wire with a conductor diameter of 1.0 mm, so that the brazing polyester imide layer has a thickness of 0.002 mm, and then a commercially available resin is applied as an upper layer. A composite enameled wire was obtained by applying and baking a 40% polyurethane enamel wire paint so that the polyurethane layer had a thickness of 0.038 mm. (Example 2) A soldering polyester imide enamel wire paint is applied and baked on a conductor wire with a conductor diameter of 1.0φmm so that the soldering polyester imide layer has a thickness of 0.003 mm, and then polyurethane enamel wire paint is applied as an upper layer. After coating and baking, the polyurethane layer becomes 0.037
A composite enamelled wire was obtained in such a way that the width was 3 mm. (Example 3) A commercially available soldering polyesterimide enamel wire paint is applied and baked on a conductor wire with a conductor diameter of 1.0φmm to give a soldering polyesterimide layer of 0.005 mm, and then polyurethane enamel is applied as an upper layer. A polyurethane layer is created by applying and baking line paint.
A composite enamelled wire was obtained with a thickness of 0.035 mm. (Example 4) A soldering polyester imide enamel wire paint was applied and baked on a conductor wire with a conductor diameter of 1.0 mm, so that the soldering polyester imide layer had a thickness of 0.008 mm, and then a commercially available polyurethane enamel wire was applied as an upper layer. A polyurethane layer is created by applying and baking line paint.
A composite enamelled wire was obtained with a thickness of 0.032 mm. (Comparative example 1) Polyurethane enamel wire paint is applied and baked on a conductor wire with a conductor diameter of 1.0φmm to form a polyurethane layer.
A polyurethane enamelled wire was obtained with a thickness of 0.040 mm. (Comparative Example 2) Apply and bake brazing polyesterimide enamel wire paint on a conductor wire with a conductor diameter of 1.0φmm so that the brazing polyesterimide layer has a thickness of 0.0016 mm, and then apply polyurethane enamel wire paint on the top layer. After coating and baking, the polyurethane layer becomes 0.0384
A composite enamelled wire was obtained in such a way that the diameter was 3 mm. (Comparative Example 3) Apply and bake brazing polyester imide enamel wire paint onto a conductor wire with a conductor diameter of 1.0φmm so that the brazing polyester imide layer has a thickness of 0.009 mm, and then apply polyurethane enamel wire paint as an upper layer. After coating and baking, the polyurethane layer becomes 0.031
A composite enamelled wire was obtained in such a way that the diameter was 3 mm. (Comparative Example 4) A soldering polyesterimide wire was obtained by coating and baking a soldering polyesterimide enamel wire paint on a conductor wire with a conductor diameter of 1.0φmm so that the soldering polyesterimide layer was 0.040 mm. Ta. FIG. 1 is a cross-sectional view showing a second embodiment of the composite enamelled wire of the present invention thus obtained. In FIG. 1, 1 is a conductor, 2 is a polyurethane layer, and 20 is a brazing polyesterimide layer. Further, Table 1 shows the results of characteristic tests of Examples 1 to 4 and Comparative Examples 1 to 4 of the composite enamelled wire of the present invention.

[Table] The test method for enamelled wire was based on JIS-C3003. Here, the AC breakdown voltage is
A twisted pair sample was twisted in accordance with JIS-C3003, and its AC breakdown voltage was determined. In addition, the low adhesion
A lead/tin=5/5 solder bath heated to 420°C was prepared, and an enameled wire was immersed in it for 5 seconds, and those with solder were evaluated as good, and those without solder were evaluated as bad. As is clear from Table 1, the polyurethane enameled wire of Comparative Example 1 has a high AC breakdown voltage of 11.0 kV at the commercial frequency of 50 Hz, but the AC breakdown voltage at 60,000 Hz rapidly deteriorates to 2.9 kV, and at 150,000 Hz, the AC breakdown voltage rapidly deteriorates to 2.9 kV. AC breakdown voltage is 1.6kv
And it gets even worse. In the case of Comparative Example 2, the AC breakdown voltage of the enameled wire at the commercial frequency of 50Hz is as high as 11.0kV, but the AC breakdown voltage at 60000Hz is 3.2kV.
The AC breakdown voltage at 150000Hz deteriorates rapidly to 1.9kV. The composite enamelled wire of Comparative Example 3 has a commercial frequency of 50
The AC breakdown voltage at Hz, AC breakdown voltage at 60000Hz, and AC breakdown voltage at 150000Hz are good, but the solderability is poor. The brazing polyester imide enameled wire of Comparative Example 4 also had AC breakdown voltage at 50Hz of commercial frequency, AC breakdown voltage at 60000Hz, and
Good AC breakdown voltage at 150000Hz, but poor brazing properties. On the other hand, the composite enamelled wires of Examples 1 to 3 of the present invention have an AC breakdown voltage at a commercial frequency of 50Hz, an AC breakdown voltage at 60000Hz,
Both the AC breakdown voltage and brazing properties at 150000Hz showed excellent results. [Effects of the Invention] The composite enameled wire of the present invention has excellent AC breakdown voltage characteristics at a commercial frequency of 50 Hz and high frequency AC breakdown voltage characteristics, and also has low-temperature brazing properties comparable to polyurethane enameled wires. , which is useful as a magnet wire for coils of high-frequency electrical equipment.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the composite enamelled wire of the present invention. 1... Conductor, 2... Polyurethane layer, 20...
Low-adhesive polyester imide layer.

Claims (1)

[Claims] 1. In a composite enameled wire comprising a solderable polyesterimide layer provided directly on the conductor and a polyurethane layer provided on the solderable polyesterimide layer, the solderable polyesterimide layer accounts for 5 to 20% of the total film thickness. 1. A composite enameled wire, wherein the brazing polyurethane layer is made of a non-linear polyurethane resin.