JPH01260714A - Insulated electric wire - Google Patents

Abstract

PURPOSE:To prevent the occurrence of any damage caused from an increase in winding speed by applying, an insulating paint having a specified amount of given ultraparticulate tetrafluoroethylene oligomer added to the resin portion of said insulating paint, to a conductor and baking the insulating paint. CONSTITUTION:A conductor is coated with an insulating paint having 0.1 to 10wt.% of tetrafluoroethylene oligomer being of an average particle diameter below 10 micrometers and of a mean molecular weight below 500 to 10,000 added to the resin portion of said insulating paint, and then baked or coated and baked via another insulating film. This results in a low coefficient of fric tion, superior wearproofness and improved heat resistance also, with high speed winding operations being kept free from any damage of the insulating film.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an insulated wire used for a wide range of purposes, such as wire for equipment coils such as electrical and communication equipment.

"Prior art" Insulated wires are manufactured in the winding process during the manufacturing of the device coils.
They were damaged by nozzles, pulleys, etc., which caused layer shorts and grounding defects. Particularly in recent years, as winding speeds have increased, electric wires have been subjected to harsh conditions, so the above-mentioned phenomenon has tended to occur frequently, and a solution to this problem has been desired.

In order to prevent the occurrence of scratches, it is necessary to reduce the friction coefficient of the winding and increase its wear resistance. For this reason, insulated wires have traditionally been coated with lubricating oil or coated with a synthetic resin such as nylon or polyethylene, which has a low coefficient of friction.

``Problem to be solved by the invention'' However, the former could not keep up with the increase in winding speed and did not contribute to solving the problem. The latter requires an extra coating process with the synthetic resin, and depending on its compatibility with the insulation film, the heat resistance may decrease.If the coil is impregnated after winding, the temperature range from room temperature to the high temperature of the actual usage condition may be exceeded. The problem was that the adhesion strength decreased.

An object of the present invention is to improve conventional insulated wires and provide an insulated wire that has a low coefficient of wear, excellent wear resistance, and does not impair heat resistance.

``Means for solving the problem'' This problem requires an average particle diameter of 10 μm or less and an average molecular weight of 50 μm or less.
An insulating paint made by adding 0 to 10,000 ethylene tetrafluoride oligomers in an amount of 0.1 to IO% by weight based on the resin content of the insulating paint can be applied directly to the conductor and baked, or another insulating film can be applied. This problem is solved by the present invention, which is characterized in that it is formed by coating and baking.

This will be explained in more detail below.

The tetrafluoroethylene oligomer used in this invention is
It is a solid powder whose average molecular weight is in the range of 500 to 10,000, and whose average particle diameter is 10 μm or less. If the average molecular weight of this oligomer is less than 500, it will become liquid, and sufficient wear resistance will not be obtained.
If it exceeds 0, the dispersibility in the insulating paint will deteriorate, resulting in a disadvantage, but by setting the average molecular weight preferably in the range of 1,000 to 5,000, better characteristics can be obtained. Furthermore, if the average particle force of the ultrafine tetrafluorinated ethylene oligomer exceeds <10 μm, the appearance of the wire becomes poor and it cannot be used as an insulated wire. Moreover, if the amount added exceeds 10% by weight, the appearance of the electric wire will deteriorate and it will be difficult to fix it with impregnated varnish, and if it is less than 0.1% by weight, no improvement in wear resistance will be observed. The preferred amount is 0.
．． It is 5 to 5.0% by weight.

Insulating paints to which ultrafine tetrafluoroethylene oligomer is added include epoxy, modified epoxy, acrylic, polyamide, polyvinyl formal, modified polyvinyl formal, polyurethane, polyester, modified polyester, polyesterimide, and modified Examples include those made of polyesterimide, polyhydantoin, polyimidazopyrrolone, polyamideimide, polyimide-modified polyimide, and the like.

This ultra-fine tetrafluoroethylene oligomer has a low molecular weight compared to tetrafluoroethylene resins with an average molecular weight of 50,000 or more, so it has very good dispersibility in insulating paints. Not only do additives such as auxiliaries become unnecessary, but the paint also has better storage stability. Therefore, to add it to the insulating paint, it is sufficient to simply add a predetermined amount of the ultrafine fluorinated ethylene oligomer to the insulating paint and stir it, which will sufficiently disperse it.

The insulating paint obtained in this way can be applied and baked directly onto the conductor, but in this case, the adhesion with the conductor decreases, so it is usually better to apply and bake it through another insulating film to improve the contact with the conductor. This is advantageous in terms of adhesion. In this case, the preferred film thickness ratio is approximately 1/10 to 5/1O.

Such insulated wires have a low coefficient of friction and excellent abrasion resistance due to the presence of ultrafine tetrafluorinated ethylene oligomers in their insulating coating. The adhesion force is also improved. In particular, ultrafine fluorinated ethylene oligomers have good dispersibility in insulating paints, so even in the later insulating coatings, the particles do not aggregate and are uniformly dispersed, which improves wear resistance. The improvement in the coefficient of friction and the decrease in the coefficient of friction are extremely significant, and furthermore, there is no occurrence of cracks or cracks in the insulation film when the insulated wire is bent.

Hereinafter, the effects of the present invention will be clarified by showing experimental examples.

"Experimental example" (Experimental example 1) Polyester imide paint (
(manufactured by Dainippon Seika Kogyo Co., Ltd.) and baked to a film thickness of 17 μm.
A polyesterimide wire having an insulating film of m was prepared.

On the other hand, in the above polyesterimide paint, (a) tetrafluoroethylene oligomer (liquid) having an average molecular weight of 400 (b) tetrafluoroethylene oligomer having an average molecular weight of 1000 and an average particle diameter of 1 μm (c) an average molecular weight of 15000 and an average particle diameter 5 μm tetrafluoroethylene oligomer (d) A paint was prepared by adding 1.0% by weight of tetrafluoroethylene resin with an average molecular weight of 50,000 and an average particle size of 1 μm, and this was applied to the above polyesterimide wire and baked. A coating film of 3 μm was formed.

Regarding these insulated wires, flexibility (self diameter), thermal softening temperature (JISC3003, 10, 1>, reciprocating wear (JI
SC3003°13, 1.1 (2)), and the adhesion strength with impregnated varnish was measured.

The adhesion strength with the impregnated varnish was measured using a wire with a diameter of 5 mm.
This was wrapped around a mandrel for 20 turns, impregnated with esterimide-based impregnated varnish, and heated and cured at 200°C for 2 hours to form a test piece. evaluated. The results are shown in Table 1.

Table 1 From Table 1, it can be seen that good wear resistance can be obtained by using a tetrabutylated ethylene oligomer having an average molecular weight of 500 to +0000. In addition, in the paint of (d), the dispersion of the tetrafluoroethylene resin powder was poor, and although the paint was stirred for 12 hours using a ball mill, partial aggregation of particles was observed.

(Experimental Example 2) Tetrabutylene ethylene oligomer with an average molecular weight of ff1lo00 and an average particle diameter of 1 μm was added to the polyesterimide paint used in Experimental Example 1 at a concentration of (a) θ weight % (b) 0.5 weight % (c) 1 Weight% (d) 5% by weight (e) 10% by weight (r) 15% by weight The additives were applied to the polyesterimide wire used in Experimental Example I and baked to form a coating film of 3 μm.

Regarding these insulated wires, the flexibility, thermal softening temperature, reciprocating wear, adhesion to impregnated varnish, and appearance were similarly examined.

The results are shown in Table 2.

From the results shown in Table 2, it can be seen that the appropriate amount of tetrafluoroethylene oligomer to be added to the insulating paint is 0.1 to IO Shigesato%.

(Experiment Example 3) A mixture of 1% by weight of tetrafluorinated ethylene oligomer with an average molecular weight of 1 IQOO and an average particle diameter of 1 μm added to the polyesterimide paint used in Experiment Example 1 was directly applied to a round copper wire with a diameter of 0.5 ffi I and baked. As a result, an insulating film with a speed of 20 μm was formed. This insulated wire has good flexibility, a thermal softening temperature of 370°C, a reciprocating abrasion of 200 times, and an adhesion force to the impregnated varnish of 840g.

The appearance was good.

(Experimental Example 4) Add 1% by weight of the tetrafluoroethylene oligomer used in Experimental Example 3 to polyvinyl formal paint (manufactured by Tokyo Tokushu Electric Wire Paint Co., Ltd.), apply this to the polyesterimide wire used in Experimental Example 1, and bake it. A film with a thickness of 3 μm was formed. This insulated wire has good flexibility and a thermal softening temperature of 355°C.
Reciprocating wear is 240 times, and the adhesion force with impregnated varnish is 920g.
The appearance was good.

(Comparative example 1) Experimental example! An I2-nylon solution was applied to the polyesterimide wire used in 1 and baked to form a film with a thickness of 3 μm.

The flexibility of this product was good, the heat softening temperature was 320°C, the reciprocating abrasion was 67 times, and the adhesion force to the impregnated varnish was 300 g.

"Effects of the Invention" As explained above, the insulated wire of the present invention has an average particle diameter of 1
An insulating paint made by adding ultrafine tetrafluorinated ethylene oligomers of 0 μm or less and an average molecular weight of M500 to 10,000 in an amount of 0.1 to 10% based on the resin content of the insulating paint can be applied directly onto the conductor and baked. Or it is coated and baked through another insulating film, so it has a low coefficient of friction, excellent wear resistance, and high heat resistance, so the insulating film will not be damaged even during high-speed winding. do not have.

Claims (1)

[Claims] Average particle diameter of 10 μm or less and average molecular weight of 500 to 10
An insulating paint made by adding 0.1 to 10% by weight of ultrafine tetrafluorinated ethylene oligomers of 0.000 or less to the resin content of the insulating paint can be applied directly onto the conductor and baked, or through another insulating film. An insulated wire characterized by being coated and baked.