JPS6366348B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention uses a specific composition for the insulating layer resin of the insulated wire that constitutes the coil itself, and when the temperature of the coil rises above a certain temperature, the insulating layer of the insulated wire softens and melts, exposing the conductor. This relates to so-called fuse wires that cause short circuits between lines. Conventionally known insulated wires of this type include 12-nylon or an insulating paint made by adding polyurethane resin to the conductor, as shown in Japanese Patent Application Laid-Open No. 49-103181 and Japanese Patent Publication No. 51-13866. An example of this is insulated wire with baked cloth. However, materials mainly composed of 12-nylon have various drawbacks as shown below. The melting short circuit temperature of the insulating layer is fixed around the thermal softening temperature of 12-nylon (180°C), and this cannot be changed arbitrarily. Baking paint has poor stability and tends to gel. It is difficult to form a uniform coating thickness, and the allowable range of melting short circuit temperature is large. The present invention relates to an insulated wire having an insulating film of a new composition that improves the above-mentioned drawbacks. The insulated wire consists of an insulating paint containing ~40 parts by weight and 0.5 to 5.0 parts by weight of a higher fatty acid ester lubricant as an anti-adhesive agent, which is coated and baked onto a conductor. The reason why a copolyamide resin having 12-nylon as a monomer component in the molecule was used as the resin forming the insulating film in the present invention is as follows.
This is because the thermal deformation behavior is sharp and the insulation paint has good stability. In addition, the heat softening temperature of conventional 12-nylon is fixed around 180℃,
Although it is not possible to arbitrarily change the melting short circuit temperature, when copolymerized polyamide resin is used as the base material,
By blending a copolyamide resin having the same softening point as the thermal softening temperature required for design, an insulated wire having an arbitrary melting short-circuit temperature can be obtained. Examples of the copolymerized polyamide resins include 12-nylon, 6-nylon,
It is copolymerized by appropriately combining monomer components such as 6,10-nylon, 6,6-nylon, and 11-nylon. Specifically, Diamid N1901,
Examples include Diamid E62L (trade name, Daicel Chemical Industries, Ltd.). In addition, specific examples of phenolic resins include Hytanol 1140 (trade name of Hitachi Chemical Co., Ltd.), PP-3121, PP-3007.
(Gun-ei Chemical Industry Co., Ltd. product name). Addition of this phenolic resin lowers the viscosity of the insulating paint, thereby improving the baking efficiency during manufacturing and making it possible to form a uniform coating film. Furthermore, if the baking is insufficient, the film will stick due to residual solvent if only the copolyamide resin is used, but this can be prevented by adding a phenolic resin.
The reason why the amount of phenolic resin added is limited to 10 to 40 parts by weight is that if the amount of phenolic resin added is 40 parts by weight or more, the mechanical strength of the insulating film (processing deterioration that the insulating film undergoes during coil winding) etc.), the plasticizing effect of the phenolic resin significantly lowers the inherent heat softening temperature of the polyamide resin, and the solvent resistance of the insulating film deteriorates. Furthermore, if the amount of phenolic resin added is less than 10 parts by weight, the effect of lowering the solvent viscosity of the polyamide resin cannot be expected, the stability of the paint will be lost, the workability of coating on copper conductors will deteriorate, and furthermore, the phenolic resin The effect of adding the resin is expected to reduce the strong adsorption force between the copolymer resin that makes up the insulating film and the cresol solvent, and improve the scattering of the cresol solvent from the insulating film. This is because it becomes impossible to do so. Addition of phenolic resin can prevent film adhesion caused by residual solvent, but copolyamide resin has a film that does not have lubricity, and slips poorly on the surface of the rotating feed roll of the baking furnace during the coating process. For this reason, when the wire passes through the rotating rolls and enters the next applicator, the wire becomes sag, leading to severe breakage. The sagging of the wire can be solved by increasing the slippage between the rotating roll and the enamel film, and after various studies, it has been found that higher fatty acid esters are effective as lubricants because they have good compatibility with polyamide. In addition, the number of parts of higher fatty acid ester added is 0.5.
The reason why the amount is limited to 5.0 parts by weight is because the effect as a lubricant is not observed if it is less than 0.5 parts by weight, and there is no difference in the effect of the lubricant even if it is added in excess of 5.0 parts by weight. Next, examples of the present invention will be described. As copolymerized polyamide resin, The composition ratio of A units: B units: C units = (20 to 60)
A composition having a composition within the range of weight%: (40 to 80) weight%: (5 to 50) weight% is used, and as a phenol resin, a resin obtained by reacting phenol and formalin under an acid catalyst is used. Softening point is 100~
A novolak type phenolic resin is used which is in the range of 130°C and is solid at room temperature. A resin having the composition shown in Table 1 was dissolved in a mixed solvent of m-cresol and xylene to prepare a paint with a resin concentration of 10%, and the paint was coated on a 0.10 mm copper wire and baked to produce an insulated wire according to the present invention.

【table】 Table 2 shows the characteristics of the insulated wires of each example.

[Table] *In the coil short circuit temperature test, a voltage of 100V was applied to the primary coil of each wire used in the example wound with 1600 turns, and on the other hand, a polyurethane copper wire with a conductor diameter of 0.32 mm was wound with 200 turns. The turned coil is the secondary side, and this terminal is shot, so when current flows through the primary coil, an overcurrent will flow and the temperature of the transformer will rise. A CC thermocouple was inserted between the primary and secondary coils to determine the melting temperature. According to the present invention having the above-described structure, the drawbacks of conventional insulated wires of this type can be overcome, and a fuse wire having any desired coil short-circuit temperature required for design can be obtained.

Claims (1)

[Claims] 1. Add 10 to 40 parts by weight of a phenol resin to 100 parts by weight of a copolyamide resin having 12-nylon as a monomer component in the molecule, and blend 0.5 to 5.0 parts by weight of a higher fatty acid ester lubricant as an anti-blocking agent. An insulated wire with fuse characteristics characterized by coating and baking an insulating paint on a conductor.