JP2006252852A - Insulated wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive insulated wire with improved scratch resistance, lubricity, corona resistance, etc. <P>SOLUTION: An insulating film provided to a conductor contains at least layered clay mineral or a carbon nanotube, and a resin of the insulating film is a resin selected from vinyl chloride, polyethylene, polyester, polyurethane, polyamide, polyimide, polyesterimide and polyamidoimide. Thereby, even with one layer of the film, the insulated wire having sufficient scratch resistance, lubricity and corona resistance can be provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an insulated wire having improved scratch resistance, lubricity, corona resistance and the like.

  Insulated wires are obtained by forming an insulating film on the surface of a copper or aluminum conductor wire by applying a resin such as polyester or polyamide by baking or extruding, and are used in various fields.

  When using insulated wires as windings, there are demands such as high efficiency, high space factor, omission of impregnation varnish process from the work and global environment, miniaturization and weight reduction, prevention of coil heat generation, high voltage response, etc. ing. The insulating film is also required to have heat resistance, water resistance, refrigerant resistance, and the like. In order to realize these required characteristics, scratch-resistant windings, irregular windings such as square wires and rectangular wires, self-bonding windings, ultrafine wires, high heat conduction windings, corona resistance windings, etc. have been developed. ing.

  For example, in order to improve the scratch resistance, two or more insulating films are applied, the lower layer is made of ester imide having high adhesion to the conductor, and the upper layer is made of amide imide having a small static friction coefficient and improved lubricity. It becomes composition.

  Applying two or more layers of insulating films using different resins in this manner is a commonly performed method. For example, a three-layer insulated wire capable of thinning the insulating film is known (for example, patents). Reference 1).

  Further, as an insulated wire excellent in lubricity and workability, a method of dispersing a liquid obtained by mixing a fluororesin in a solvent having a surface tension at 25 ° C. of 30 dyn / cm or less into a polyamide-imide resin, and using the paint as a film, A method of adding fluororesin powder to the outermost insulating layer, or a method of applying an organic lubricant that is solid at room temperature with a limited number of main chain carbon atoms to a liquid organic lubricant at room temperature, etc. are known. (See Patent Documents 2, 3, and 4).

Moreover, in order to improve lubricity at low cost, it is common practice to apply paraffin or wax to the surface of the insulating film.
Japanese Patent No. 3307435 Japanese Patent No. 2519814 Japanese Patent No. 2686148 Japanese Examined Patent Publication No. 7-73008

  In the conventional method of applying two or more insulating films, since an interface exists between the films, the mechanical strength or thermal shock may cause a decrease in bonding strength at the interface, and the film may be peeled off. For this reason, there are cases in which an insulating film improved to satisfy the required characteristics for an insulated wire as described above cannot exhibit sufficient characteristics. In addition, when the film is thickened or stacked in layers, the diameter of the insulated wire increases, and in order to use it as a winding, it tends to go against increasing the space factor and downsizing.

  In addition, since the conventional insulating film uses an expensive material such as a fluororesin, the material cost may increase or sufficient corona resistance may not be obtained.

Furthermore, applying paraffin or wax to improve lubricity cannot be used in sealed compressor motor applications because the paraffin and wax are melted by the refrigerant and lubricating oil, causing clogging of the capillary. The use of an insulated wire will be limited.

  The present invention solves the above-described problems, and an object thereof is to provide an insulated wire that is inexpensive and has improved scratch resistance, lubricity, corona resistance, and the like.

  In order to solve the above problems, in the present invention, an insulated wire containing at least a lamellar clay mineral or carbon nanotube is used for an insulating film applied to a conductor. Thereby, scratch resistance, lubricity, and corona resistance can be improved without increasing the film thickness or increasing the coating layer.

  The layered clay mineral is a layered silicate, kaolinite, dickite, halloysite, chrysotile, lizardite, amesite, pyrophyllite, talc, montmorillonite, beidellite, saponite, hectorite, saconite, vermiculite, paragonite, lepidrite, It is preferably at least one selected from margarite, clintnite, anandite, dombasite, kukkeite, suedoite, clinochlore, chamosite, nimite and mica.

  In addition, the current insulation wire manufacturing method and equipment use that the resin that forms the main part of the insulation film is a resin selected from vinyl chloride, polyethylene, polyester, polyurethane, polyamide, polyimide, polyesterimide, and polyamideimide. It is preferable because it is easy.

  Further, it is preferable that the outermost layer of the insulating film is a fusion layer, so that varnish treatment after winding can be made unnecessary.

  As described above, the insulated wire of the present invention has a nano-sized layered clay mineral or carbon nanotube, which is an inorganic filler, and has a lower cost than a conventional lubricated insulated wire, even with a single layer coating. An insulated wire having sufficient scratch resistance, lubricity, and corona resistance can be provided.

  Further, lubricity can be stably improved without applying wax or paraffin to the surface of the electric wire as in the prior art.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples.

  The resin used for the insulated wire film of the present invention may be any resin, and any resin usually used for insulated wires can be used. In particular, vinyl chloride, polyethylene, polyester, polyurethane, polyamide, polyimide, polyesterimide, and polyamideimide are preferable in terms of characteristics and handling.

In addition, the layered clay mineral is a layered silicate, kaolinite, dickite, halloysite, chrysotile, lizardite, amesite, pyrophyllite, talc, montmorillonite, beidellite, saponite, hectorite, soconite, vermiculite, paragonite, lepidrite, It is preferably at least one selected from margarite, clintonite, anandite, donbasite, kukkeite, suedoite, clinochlore, chamosite, nimite and mica. Further, among them, a layered silicate belonging to the smectite group or the mica group is preferable.

  These layered clay minerals need to be stably dispersed layer by layer in the insulating film. Therefore, it is preferable to use an interlayer insertion method. In the interlayer insertion process, the following two methods are mainly used.

  One is an ionic interlayer modification method in which sodium ions and the like are exchanged between clay layers with an onium such as a quaternary alkyl ammonium salt.

  The other is a method of organically modifying the clay layer by forming secondary bonds between the clay interlayer ions and the dipole of the strong polar modifier.

  The layered clay mineral treated in such an intercalation step is mixed and dispersed in the insulating film resin solution.

  Carbon nanotubes preferably have a diameter of several to several tens of nm and a length of several μm to several mm.

  In addition, the addition ratio of the layered clay mineral is preferably 0.5 to 40 wt% in the insulating film resin. Furthermore, 1.0 to 10 wt% is more preferable. If the amount is too small, a sufficient effect cannot be obtained. If the amount is too large, the viscosity of the insulating film resin solution becomes large, making it difficult to apply, and stable production cannot be achieved. In addition, the cured insulating film becomes hard, the flexibility of the insulated wire is reduced, the workability by bending and pulling is lowered, and cracks and crazing are likely to occur.

  Moreover, the addition ratio of the carbon nanotube is preferably 0.1 to 5 wt%. Since the electrical resistance is reduced by adding carbon nanotubes, sufficient insulation cannot be obtained when the amount added is increased.

  Of course, inorganic fillers or organic lubricants other than layered clay minerals or carbon nanotubes may be added. Examples of the inorganic filler include silicon oxide, calcium carbonate, alumina, zirconia, titanium oxide, boron nitride, and carbon. Examples of the organic lubricant include amide compounds such as stearic acid amide and oleic acid amide. In addition, antioxidants, flame retardants, weathering agents and the like may be added.

Moreover, you may give aromatic polyamide, an epoxy resin, etc. as a fusion | melting layer in the outermost layer of an insulation film.
Of course, lamellar clay minerals or carbon nanotubes may be added to these resins.

  The insulated wire of the present invention is a conventional general wire drawing, softening, resin solution coating, and baking hardening except that a solution in which at least a layered clay mineral or carbon nanotube is mixed and dispersed in a resin solution for an insulating coating is used. It can be manufactured by an insulated wire manufacturing method.

  Of course, when the insulating film is thickened, the coating and baking may be repeated a plurality of times as in the prior art.

  An example of the insulated wire of the present invention is shown below.

  Using polyamideimide as a non-volatile component, a solution A was prepared by dissolving it in a solvent containing N-methyl-2-pyrrolidone as a main component so as to be 30 wt%.

  As the layered clay mineral, montmorillonite composed of a phyllosilicate layer having a thickness of about 1 nm having exchangeable cations between layers was used. A layered clay mineral having an alkylammonium cation inserted between the layers of this montmorillonite was added to and mixed with the resin solution A in various amounts.

  Six types of addition amounts of 0, 0.5, 1.0, 5.0, 10.0, and 15.0 wt% were prepared. Using these solutions, a polyamide-imide film was formed on a copper wire having a wire diameter of 0.50 mm.

  Table 1 shows the results of various tests conducted on the insulated wires a to f having the different layered clay mineral contents thus obtained.

  The test was conducted according to JIS-C-3003.

この結果より、層状粘土鉱物を含まない従来の絶縁電線ａに比べて、本発明の絶縁電線は耐コロナ性、潤滑性を向上させることができる。

From this result, the insulated wire of the present invention can improve the corona resistance and lubricity as compared with the conventional insulated wire a that does not contain the layered clay mineral.

  Using polyamideimide and THEIC-modified polyesterimide as nonvolatile components, solutions B and C were prepared by dissolving each resin in a solvent containing N-methyl-2-pyrrolidone as a main component so as to be 30 wt% each.

  Instead of the layered clay mineral of Example 1, carbon nanotubes having a diameter of about 10 nm and a length of about 3 μm were used, and the resin solutions B and C were added and mixed in varying amounts. Six types of addition amounts of 0, 0.5, 1.0, 5.0, 10.0, and 15.0 wt% were prepared. Using these solutions, a THEIC-modified polyesterimide was formed on the lower layer of a copper wire having a wire diameter of 0.50 mm, and a polyamideimide film was formed on the upper layer.

  The results of evaluating these insulated wires g to l in the same manner as in Example 1 are shown in (Table 2).

このように、カーボンナノチューブを用いた場合でも、耐コロナ性、潤滑性を向上できた。

Thus, even when carbon nanotubes were used, corona resistance and lubricity could be improved.

  In this embodiment, an insulated wire having no self-bonding layer is used, but it goes without saying that a layered clay mineral or carbon nanotube may be added to the self-bonding layer.

  The insulated wire of the present invention can be manufactured by using a conventional enameled wire manufacturing apparatus as it is, can suppress the cost of the apparatus, and can easily improve the corona resistance and lubricity, and thus is industrially effective. .

Claims (4)

An insulated wire comprising an insulating film applied to a conductor containing at least a layered clay mineral or a carbon nanotube. 2. The layered clay mineral according to claim 1, wherein the layered clay mineral is a layered silicate, and kaolinite, dickite, halloysite, chrysotile, lizardite, amesite, pyrophyllite, talc, montmorillonite, beidellite, saponite, hectorite, soconite, vermiculite, paragonite. An insulated wire, characterized in that it is at least one member selected from the group consisting of lepidrite, margarite, clintnite, anandite, dombasite, kukkeite, suedoite, clinochlore, chamosite, nimite and mica. The insulated wire according to any one of claims 1 and 2, wherein the resin of the insulating film is a resin selected from vinyl chloride, polyethylene, polyester, polyurethane, polyamide, polyimide, polyesterimide, and polyamideimide. The insulated wire according to any one of claims 1 to 3, wherein the outermost layer of the insulating film is a fusion layer.