JPS6020853B2 - Insulated wire for safety coil formation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to various electrical devices that use coils made of multi-layered enamelled wire, and when an abnormality occurs in the electrical circuit and a temporary excessive current flows, the enameled wire generates heat and the enameled wire is heated. An object of the present invention is to provide an insulated wire for forming a safety coil, which has a function of easily short-circuiting the wires to each other, interrupting current, and preventing combustion of the coil.

BACKGROUND ART In recent years, with the spread of household electrical appliances, the occurrence of fires and the like has increased, and many attempts have been made to prevent such incidents.

One possibility is to improve the heat resistance of materials such as insulated wires in order to prevent the risk of fire, but this would require the materials to be extremely expensive, and on the other hand, if only heat resistance is considered, Despite the high temperatures, the equipment continues to operate, eventually leading to a fire. Therefore, it is being considered to cut off the current flowing through the equipment before an accident such as a fire occurs. Generally, devices such as transformers that use enameled wires have a fuse installed in their circuit, and when this fuse breaks, it cuts off the current, prevents ignition and combustion, and protects the entire device. It is something.

However, providing a bimetal type fuse or the like in a circuit within a device increases costs and is not practical. Therefore, recently, instead of this, enameled wire coated with an insulating film made of thermoplastic resin with a low softening temperature, mainly made of nylon 12, has been used as the winding wire for equipment such as transformers to ensure normal actual operation. Sometimes it works as an insulated wire, and in the event of an abnormality, the insulating coating softens and short-circuits, cutting off the power and preventing fire.However, the insulated fin wire, whose insulating coating is made of nylon 12, Although it exhibits sharp thermal deformation behavior that causes rapid melting, it does not have sufficient electrical or thermal characteristics as an insulated wire when operated under normal conditions.

In order to improve these points, attempts have been made to form an insulating coating using nylon 12 to which urethane resin or polyester resin is added. (Samurai Kosho 51-1 66
"Mochiseki Sho 51-48191). However, since these additive resins are thermosetting resins, depending on the amount added *
This inhibited the thermal deformation behavior characteristic of nylon 12. Also, it is easier to obtain the desired product by mixing it with a thermoplastic resin, but since there is a difficulty in compatibility between nylon 12 and other resins, it is not easy to add and use a thermoplastic resin to nylon 12. . Furthermore, thermoplastic resins other than nylon LA cannot exhibit sharp thermal deformation behavior like nylon 12. In view of the current situation, the present inventors conducted intensive research and found that the thermal deformation behavior is not inferior to that of an insulated wire with an insulating coating made of nylon 12, and the electrical and thermal properties of the insulated wire are improved. This is the discovery of an excellent insulated wire.

That is, in the present invention, the following general formula (n.

or a positive integer of 30 or more) and a thermoplastic copolymerized polyester resin other than those represented by formula '11 that is soluble in phenolic solvents, and an insulating coating is provided on the outside thereof. This is an insulated wire characterized by providing an insulating coating containing nylon 12 as a main component.

In the insulated wire of the present invention, an insulating coating made of a thermoplastic polyester resin mixture as described above is provided between the conductor and an insulating coating made of nylon 12. The reason for limiting the thermoplastic polyester resin mixture to the aromatic polyester resin having the structure shown is that the aromatic polyester represented by the above general formula is a common aromatic polyester resin such as polyethylene terephthalate (PET), polybutylene terephthalate, etc. This is because it has comparable heat resistance to (PBT) and is easily soluble in solvents, especially cresol, which is usually used as a solvent for enameled wires.

However, since the polyester resin represented by the formula {1' alone does not short-circuit at a required short-circuit temperature, that is, 20,000 or less, a thermoretroactive copolymerized polyester resin soluble in other phenolic solvents is mixed. In this way, the insulated wire of the present invention has a two-layer structure, such as an upper layer of an insulation coating of nylon 12 and a lower layer of an insulation coating of a specific aromatic polyester resin mixture. Sensitivity to temperature is significantly improved compared to when the aromatic polyester resin layer is used alone.

Further, in the present invention, the reason why the nylon 12 layer is particularly used as the upper layer is that nylon 12 has excellent mechanical properties, so it also acts as a protective layer and can prevent damage to the film during winding processing. . Next, performance examples of the present invention will be described.

Examples 1 to 5 and Comparative Examples 1 to 3 U Polymer (trade name) 1060 manufactured by Unitika Co., Ltd. as the aromatic polyester resin represented by the above formula '1' and Polyester Vylon (trade name) 20 manufactured by Toyobo Co., Ltd. as other resins Mix these in the proportions shown in Table 1 and dissolve them in cresol to prepare each paint.
300qo in a baking furnace with a length of 3 kites.
The insulated power supply of the present invention was obtained as shown in Table 1 by applying and baking a paint prepared by dissolving Daicel's Diamid (trade name) L1801 in cresol on the outside as nylon 12. .

Table 1 also lists the results of measuring the short circuit temperature and electrical and mechanical properties of the thus obtained insulated wire of the present invention.

In addition, in order to compare with the insulated wire of the present invention, a wire with a conductor diameter of 0.4 and an insulating film of nylon 12 provided on the outer periphery (Comparative Example 1)
) and those provided with only a polyester resin insulation coating (Comparative Examples 2 and 3) were made, and the characteristics of these insulated wires were measured in the same manner as above, and the results are also listed in Table 1. .

Table 1 Note '1} The short circuit temperature is the temperature when a sample of two insulated wires is placed in a constant temperature box and heated by applying 200 V AC to cause a short circuit.

As is clear from the table above, the insulated wire of the present invention has a sharp thermal deformation behavior with less variation in short circuit temperature, equivalent to that of the conventional insulated wire made only of nylon 12, so there is no risk of ignition even when the temperature rises abnormally. It has excellent thermal and electrical properties and is extremely useful as an insulated wire for forming coils in electrical equipment.

Claims (1)

[Claims] 1 Aromatic polyester resin represented by the following general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (n is a positive integer of 30 or more) on the conductor and soluble in phenolic solvent (1 ) Insulation for forming a safety coil, characterized by providing an insulating film made of a mixture with a thermoplastic copolymerized polyester resin other than that shown in the formula, and further providing an insulating film mainly composed of nylon 12 on the outside of the insulating film. Electrical wire.