JPH03184208A - Insulated electric cable - Google Patents

Abstract

PURPOSE:To prevent insulating layer from being damaged and dropping off at the time of coiling work at high speed by containing perfluoropolyether and solid powder of polytetrafluoroethylene with specified average particle size and molecular weight in the most outer insulating layer. CONSTITUTION:The most outer insulating layer is formed by using an insulating paint containing 0.01-20wt.% of perfluoropolyether and 0.1-10wt.% of solid pow der with average particle size 2mum or below of poly(tetrafluoroethylene) with average molecular weight 500-10000. The layer thus has high lubricating property and heat resistance and since high speed coiling work can be carried out, the insulating layer of an insulated cable is neither damaged nor stripped off in coil forming process by high speed coiling work and thus prescribed work can be carried out easily and stably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an insulated wire, and more particularly to an insulated wire that has excellent self-lubricating properties, wear resistance, and good resistance to processing deterioration.

[Prior art] In order to speed up the manufacturing of electric motors, transformers, etc., high-speed automatic winding machines are introduced to wind insulated wires (magnet wires), and it is possible to wind insulated wires at high speed. It is widespread.

However, when forming a coil by high-speed wire winding, if the surface of the insulated wire lacks lubricity, a large amount of tension will be applied to the insulated wire, making it susceptible to damage, and the reliability of the resulting coil will likely decrease. was there. In addition, it is desired to form compact coils depending on the purpose and use.
This required the insulated wire to be tightly wound with high tension in order to minimize the space factor of the insulated wire. However, as mentioned above, if the surface of the insulated wire has poor lubricity, the workability during winding is very poor, the space factor is limited, and it is difficult to obtain the desired coil, and the surface of the insulated wire may be damaged. There were some inconveniences such as receiving a refund.

Therefore, in order to provide an insulated wire that can be easily processed at high speed while maintaining its reliability, it has been proposed to add lubricity to the surface of the insulated wire. There is.

Methods for imparting lubricity include applying paraffin wax to the surface of the insulated wire, providing an overcoat layer made of polyamide resin, or applying and baking an emulsion (friction reducer) containing paraffin wax. There are methods such as forming a thin anti-friction layer on the surface.

[Problems to be Solved by the Invention] However, with the method of applying paraffin wax described above, there is a problem that the paraffin wax peels off during high-speed winding, making it impossible to maintain sufficient lubricity. The method of providing an overcoat layer has disadvantages such as insufficient heat resistance.

In addition, the method of applying and baking an antifriction agent has high lubrication +h and high workability, but when used for hermetic motors such as compressors for air conditioners and refrigerators, it is difficult to coat the surface of insulated wires. The thin lubricant layer that is formed can be extracted into the refrigerant or motor oil of air conditioners and refrigerators, causing various problems.

Therefore, this invention solves the above-mentioned problems, has high lubricity and heat resistance, is capable of high-speed winding processing, and is capable of
An object of the present invention is to provide an insulated wire that can stably maintain high lubricity even when used for a specific purpose.

[Means for Solving the Problems] This invention provides an outermost insulating layer made of 0.01 to 20% by weight of bellfluoropolyether and polytetrafluoroethylene having an average particle size of 2 μm or less and an average molecular weight of 500 to 10,000. The solution was to form it from an insulating paint containing 0.1 to IO weight percent of solid powder.

[Function] Therefore, the insulated wire of the present invention has high lubricity and heat resistance, and high-speed winding is possible, so even when forming a coil by high-speed winding, the insulation layer of the insulated wire is The desired work can be easily and stably performed without falling off or being damaged by scratches, etc., and highly reliable coils can be obtained. In addition, when this product is used for hermetic motors such as air conditioners and refrigerators, the insulating layer can minimize the amount of extraction into the refrigerant or motor oil, and the amount of extraction is stable, so there are no problems. It also has the advantage of not causing any problems and being used for a wide range of purposes.

Hereinafter, the insulated wire of the present invention will be explained in detail.

This insulated wire has at least one insulating layer on a conductor made of copper or the like, and the outermost insulating layer contains 0.01 to 20% by weight of perfluoropolyether.
Average particle size of 2 μm or less and average molecular weight of 500 to 1000
0 solid powder of polytetrafluoroethylene 0.1-1
% by weight of an insulating paint.

The perfluoropolyether used here is a fluorocarbon polymer having a linear or branched structure having +CF, -0) in the main chain.

Specifically, for example, as a linear one, →CF t-
c F , -o←→cpf-o)y-...(1)+C
F! -CF', -CF, -0 configuration...
(2), etc., and CF is a branched type.

+CF -CF t-0) -If-(CF t-Ohr
...(3) CF3 A: CF -CF t-Oh"
... (4), etc., but from the viewpoint of the effect of imparting lubricity, those having a linear structure are preferably used, and among them, those of general formula (2) are preferred. Further, as the average molecular weight, those having an average molecular weight of about 1,000 to 20,000 are preferably used. If the molecular weight is less than this range, the loss due to evaporation during baking will be large, and if the molecular weight exceeds the above range, it will become solid and difficult to handle, which is not preferred.

The amount of such perfluoropolyether added is 0.0
1-20% by weight, more preferably 0. 1-10% by weight
It is said that If it is less than 0.01% by weight, the effect of improving lubricity will not be sufficiently obtained, and if it exceeds 20% by weight, the insulated wire will become sticky and will be difficult to handle, and when used for hermetic motors such as compressors. This is because there is a disadvantage that a large amount of extracted material is extracted into the refrigerant or motor oil.

Furthermore, the polytetrafluoroethylene powder used in this invention has an average molecular weight of 500 to +000
00, more preferably 1000 to 5000, and the average particle size of the powder is 2 μm or less. If the average molecular weight is less than 500, it becomes liquid and sufficient abrasion resistance cannot be obtained, and if it exceeds 10,000, the dispersibility in insulation paint deteriorates, which is disadvantageous.

Furthermore, if the average particle size of the polytetrafluoroethylene powder exceeds 2 μm, the appearance of the wire becomes poor and it cannot be used as an insulated wire.

The amount of polytetrafluoroethylene powder added is
0.01 to IO% by weight, more preferably 0.5 to 5.0% by weight. If it is less than 0.1% by weight, no improvement in wear resistance will be observed, and if it exceeds 10% by weight, the appearance of the wire will deteriorate, which is inconvenient.

Such polytetrafluoroethylene powder has a lower molecular weight than polytetrafluoroethylene, which has an average molecular weight of 50,000 or more, so it has very good dispersibility in insulating paints, and it does not require surfactants or dispersion aids. Not only do additives such as these become unnecessary, but the paint also has better shelf life. Therefore, addition to insulation paint simply adds a predetermined amount of polytetrafluoroethylene powder to insulation paint,
Only stirring is required, which enables sufficient dispersion.

Since such an insulated wire has polytetrafluoroethylene powder dispersed in its insulating layer, it has a low coefficient of friction and excellent wear resistance.

Moreover, because it contains bellfluoropolyether, which is compatible with polytetrafluoroethylene and has excellent lubricity by itself, it exhibits even better wear resistance than when used alone. .

As a 4-filament insulating paint containing such perfluoropolyether and polytetrafluoroethylene powder,
For example, polyurethane, polyvinyl formal, polyester, polyesterimide, polyhydantoin, polyamideimide, polyesteramideimide, polyhydantoin ester, polyesteramide, and the like are preferably used.

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 will be reduced, so it is usually better to apply and bake it through another insulating layer to ensure that the conductor does not stick to the conductor. This is advantageous in terms of adhesion. In this case, the preferred thickness ratio between the insulating layer and other insulating layers is approximately 1/20 to 1/20.
It is 2.

In the insulated wire thus obtained, the outermost insulating layer contains 0.01 to 20% of perfluoropolyether.
weight% and polytetrafluoroethylene powder is 0.1-
Since it contains 10% by weight, it has high lubricity and good wear resistance, making it possible to perform high-speed wire winding without causing damage or falling off of the insulating layer, even during high-speed winding. A highly reliable coil etc. that is densely wound can be obtained. Moreover, the inclusion of perfluoropolyether and polytetrafluoroethylene powder in the insulating layer does not cause a decrease in the heat resistance of the insulated wire. It is also suitable for use in hermetic motors of compressors such as air conditioners and refrigerators, since the amount extracted into the refrigerant or motor oil is small.

Hereinafter, a more detailed explanation will be given with reference to examples.

[Example: A polyester imide paint (manufactured by Dainichiseika Kogyo Co., Ltd.) was applied to a round steel wire with a diameter of 0.5 cm and baked to form a film of 1p! A 7 μm-thick insulating layer was formed to prepare a polyesterimide wire.

On the other hand, according to the compounding amounts shown in Table 1, Verfluoroboriether Demnum 565 (
(manufactured by Daikin Industries, Ltd.) and polytetrafluoroethylene powder to prepare various insulating paints.

This insulating paint was applied to the surface of the polyesterimide wire and baked to form an insulating layer with a thickness of 3 μm, thereby producing insulated wires of Examples and Comparative Examples.

The characteristics of the insulated wires of the examples (9 examples) and comparative examples (14 examples) obtained as described above were determined according to JIS ('', 1 1
1 +1 Q +, = fikl −r−b)A
f-Man -mn, h←heat resistance, number of reciprocating wear,
The measurement results of the static friction coefficient and extraction rate are summarized in Table 1. In addition, the presence or absence of precipitates in each insulating paint was visually checked, and the results are also shown in Table 1. However, the static friction coefficient was measured using an electric wire slip tester manufactured by Toyo Seiki Co., Ltd. under a load of 200 g. Further, the number of reciprocating wear was measured according to the old JIS standard C3003-.

(Hereinafter, blank space) From Table 1, the insulated wires of Examples have excellent abrasion resistance, heat resistance, low extraction rate, good appearance and flexibility, and have excellent well-balanced performance. However, it has also become clear that the insulating paint has good handling properties since there are no precipitates in it.

On the other hand, in Comparative Example 1 in which neither bellfluoropolyether nor polytetrafluoroethylene was added, and Comparative Examples 2 and 4 in which neither bellfluoropolyether nor polytetrafluoroethylene was added, It was found that the number of wears was extremely small and the wear resistance was low. Moreover, in Comparative Example 3.5, in which the amount of either perfluoropolyether or polytetrafluoroethylene exceeded the range of the present invention, the appearance was poor.

In addition, in Comparative Example 6.7, in which only one of bellfluoropolyether and polytetrafluoroethylene was blended, and the amount was excessive, not only did the appearance look bad, but the amount of the former was especially excessive. In Comparative Example 6, the extraction rate was high, and in Comparative Example 7, in which the latter was added in an excessive amount, a precipitate was formed in the insulating paint. Furthermore, in Comparative Example 8 in which both were added in excess, the appearance was poor, the extraction rate was high, and many precipitates were observed in the paint. Further, Comparative Example 9 uses polytetrafluoroethylene having a particle size and molecular weight exceeding the range of the present invention. +0.12.13, the appearance was very bad and the abrasion resistance was insufficient, and especially in Comparative Example 9 using a material with a large molecular weight, precipitates were formed in the insulating paint. Furthermore, in Comparative Example 10 in which a liquid polytetrafluoroethylene was used, the appearance was good, but the extraction rate was high and the abrasion resistance was low.

[Effects of the Invention] As explained above, the insulated wire of the present invention has an outermost insulating layer containing 0.01 to 20% by weight of perfluoropolyether;
Average particle size of 2 μm or less and average molecular weight of 1500 to 1000
0 solid powder of polytetrafluoroethylene 0.1-1
Since it contains 0% by weight, it has high lubricity and enables high-speed wire winding, so it is highly reliable without causing scratches or falling off of the insulating layer during high-speed winding. Coils etc. can be easily obtained. Furthermore, when used for hermetic motors such as air conditioners and refrigerators, it is possible to minimize the amount of extraction into the refrigerant or motor oil, and the amount of extraction is stable, so there is no problem. It does not cause any problems and can be used for a wide range of purposes. Furthermore, the insulating paint used for this insulated wire has good storage stability, and there is the advantage of not requiring strict storage conditions even when stored for a long period of time.

Claims (1)

[Claims] (1) The outermost insulating layer is perfluoropolyether 0.0
1 to 20% by weight, and 0.1 to 10% by weight of solid powder of polytetrafluoroethylene having an average particle size of 2 μm or less and an average molecular weight of 500 to 10,000.