JPS6021664B2 - insulated wire - 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 to a certain temperature, the insulating layer of the insulated wire softens and melts. This relates to so-called fuse wires, where the conductor is exposed and a short circuit occurs between the wires.

This type of insulated wire was previously known as
As seen in Japanese Patent No. 103181 and Japanese Publication No. 51-113866, examples include insulated wires in which a conductor is coated with an insulating paint made of nylon-12 or nylon-12 to which a polyurethane resin is added.

However, materials based on nylon-12 have various drawbacks as shown below. (2) The melting short-circuit temperature of the insulating layer is fixed around the thermal softening temperature of nylon-12 (180 qo), and cannot be changed arbitrarily. ■Baking paint has poor stability and tends to gel. (2) It is difficult to form a uniform coating thickness, and the allowable 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 invention consists in an insulated wire in which a conductor is coated with an insulating paint containing 20 to 6 parts by weight of a brominated epoxy resin.

The reason for using an epoxy resin as the resin for forming the insulating coating film in the present invention is that it is a general-purpose resin and resins with any softening point are available, from low softening temperature ones to high molecular weight solid ones, and This is because the compatibility between each grade is good.

High molecular weight epoxy resin with a molecular weight of 30,000 or more is the main component for forming an insulating film, and specifically, Epomate YP-
Examples of 4 include S-2 Spot (trade name, Toto Kasei Co., Ltd.), Eponol OL55 (trade name, Shell Chemical Co., Ltd.), and PKHH (trade name, Union Carbide Co., Ltd.). In addition, a low molecular weight brominated epoxy resin with an epoxy equivalent of 400 to 3500 is blended to arbitrarily set the melting short-circuit temperature of the insulating film, and specifically YDB-500 is a special type of brominated epoxy resin. , 700 (trade name of Toto Kasei Co., Ltd.) and YPT-4WS2 porridge (trade name of the same company), which is a bisphenol-A type brominated epoxy resin, are effective. High-molecular-weight epoxy resin with a molecular weight of 30,000 or more has excellent adhesion with conductors and film-forming properties, and by using this resin as a base material and blending it with a low-molecular-weight brominated epoxy resin with a low softening point, it can be melted into any desired state. It is possible to obtain an insulated wire having a short circuit temperature.

The blending amount of the low molecular weight brominated epoxy resin is in the range of 20 to 60 parts by weight based on 100 parts by weight of the above-mentioned high molecular weight epoxy resin, providing good film properties. Next, examples of the present invention will be described.

A resin having the composition shown in Table 1 is dissolved in a mixed solvent of m-cresol and xylene to make a paint with a resin concentration of 25%, and the paint is coated on a 0.150-bar copper wire to produce an insulated wire according to the present invention. did. Table 2 shows the characteristics of the insulated wires of each example.
Shown below. Table-1 Paint formulation table-2 Characteristics test results
The test was conducted using a test transformer to which a voltage of 0 V was applied, and a coil in which a polyurethane copper wire with a conductor diameter of 0.4 was wound 230 turns was used as the secondary side, and the terminals of this coil were short-circuited.

Since the terminals of the secondary coil are short-circuited, when current flows through the primary coil, an overcurrent flows and the temperature of the transformer rises. Since the conductor resistance changes as the temperature of the transformer increases, this change was measured and converted into resistance from the resistance value at the time of fusing to determine the fusing temperature. According to the present invention having the above structure, a low molecular weight brominated epoxy resin having an epoxy equivalent of 400 to 3500 is added to a high molecular weight epoxy resin having a molecular weight of 30,000 or more, which is an insulating film forming component. It is possible to solve the disadvantages of the electric wire and to obtain a fuse electric wire having any coil short-circuit temperature required in the design, as shown in Table 2.

Claims (1)

[Claims] 1 100 parts by weight of a high molecular weight epoxy resin with a molecular weight of 30,000 or more as an insulating film forming component, and an epoxy equivalent of 400 to 400 to arbitrarily set the melting short-circuit temperature of the insulating film.
An insulated wire having fuse characteristics characterized in that an insulating paint containing 20 to 60 parts by weight of a low molecular weight brominated epoxy resin of 3500 is applied and baked onto a conductor.