JPS58804B2 - insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an insulated wire, particularly an enamel wire, which is made by modifying low molecular weight polypropylene with a higher fatty acid derivative such as a higher fatty acid, a higher fatty acid ester, or a higher fatty acid amide, and which has further improved lubricity than that of polypropylene alone. It's about lines.

The enameled wire is subjected to severe mechanical abrasion and careful molding in automatic winding machines.

For this reason, enamelled wires are susceptible to mechanical damage, and electrical insulation failures, ie, layer shorts, often occur from this damaged portion.

An object of the present invention is to provide an enameled wire in which the lubricity of the coating is further improved compared to the case of polypropylene alone, in order to reduce mechanical damage to the insulation coating during automatic winding.

A feature of the present invention is that, in order to improve the lubricity of the enamel film, low molecular weight polypropylene is modified by adding higher fatty acids, higher fatty acid esters, higher fatty acid amides, vegetable oils, etc., and this is formed as a thin film on the insulating film. It is at the point.

The low molecular weight polypropylene used in the present invention may be synthesized by a conventional method or may be a commercially available product.

Commercially available low-molecular polypropylenes include Viscoll 660-P (average molecular weight 3,000) manufactured by Sanyo Kagaku Co., Ltd., Viscol 550-P (average molecular weight 4000) manufactured by Chiba Fine Chemical Co., Ltd., and Vistak (average molecular weight 5,000) manufactured by Chiba Fine Chemical Co., Ltd.
~20.000 grade product) Also Vistac C, C
(grade products with an average molecular weight of 10,000 to 30,000), etc.

The thermal softening points of these commercially available low molecular weight polypropylenes are all 150°C or lower.

As the higher fatty acid, stearic acid is generally used, and lauric acid, myristic acid, and valmitic acid can also be used.

As the higher fatty acid ester, butyl stearate, beeswax (main component: mericyl palmitylate), carnauba wax (main component: myricyl cerotate), lanolin, ethylene glycol monostearate, etc. are used.

As the higher fatty acid amide, stearic acid amide, palmitic acid amide, methylene bis stearamide, ethylene bis stearamide, etc. are used.

Vegetable oils include drying oils such as soybean oil, tung oil, and linseed oil;
Semi-drying oils such as sesame oil and cottonseed oil, non-drying oils such as olive oil and peanut oil, etc., may be used as long as they contain unsaturated fatty acid esters such as oleic acid and linoleic acid of glycerin as a main component.

In the present invention, the reason why the average molecular weight of the low-molecular polypropylene is set to i,ooo~30,000 is that if it is less than 1.000, the molecular weight is too low and brittle and cannot exhibit sufficient mechanical properties as a lubricating layer of an enameled wire. .

In addition, low-molecular polypropylene with an average molecular weight of 30,000 or more has a high thermal softening point, resulting in a decrease in high-temperature fluidity during enamel coating.

The reason why the thermal softening point of the low molecular weight polypropylene is set to about 170° C. or lower is to prevent foaming of the enamel coating lubricating layer film.

In other words, the baking temperature of a mixture consisting of low-molecular polypropylene with a thermal softening point of 170°C or higher and higher fatty acids or derivatives thereof must be 200°C or higher; however, at such high temperatures, the thermal decomposition of low-molecular polypropylene This is because foaming of the baked enamel film is inevitable.

The present invention is characterized by a lubricating film composed of a mixture of low-molecular polypropylene and one or more higher fatty acids or derivatives thereof. 100
Parts by weight are appropriate.

Further, the thickness of the lubricating layer is not particularly limited as long as it is formed thinly, and a thickness of 2 μm or less is sufficient in practice.

The enameled wire used in the present invention may be any enameled wire that is in practical use. For example, various enameled wires such as formal wire, polyurethane wire, polyester wire, polyesterimide wire, polyamide wire, etc. can be used.

Comparative examples and examples of the present invention are shown below.

The lubricity was evaluated based on the magnitude of the static friction coefficient. [Comparative example] The static friction coefficient of a type 1 polyester wire 1.0 mm with a conductor diameter of LO mm and a coating thickness of 0.036 mm was 0.13 to 0.17.
Met.

[Comparative Example 1] 2 g of polypropylene having an average molecular weight of 900 and 2 g of stearic acid are dispersed and dissolved in toluene 96.9 g.

Add this solution to one type of polyester wire 1.0mm5z! The upper layer of R was applied by drawing with a die, and baked by passing through a heating furnace with a furnace temperature of 200° C. and a furnace length of 6 m at a speed of 22 m/min.

The lubricant layer thickness of the obtained self-lubricating enameled wire was 0.00
1 mm, but the lubricating layer was easily peeled off when rubbed with a fingernail, making it impractical for industrial use.

[Comparative Example 3] 2 g of polypropylene with an average molecular weight of 31,000 and a heat softening point of 175°C, 2 g of stearic acid, and 96 g of toluene.
Disperse and dissolve.

This solution was mixed with Type 1 polyester 1.0i according to Comparative Example 2.
It was coated and baked on i and g.

The appearance of the obtained self-lubricating enameled wire was rough and foamed, and the coefficient of static friction was 0.11 to 0.12.

[Example 1] 2 g of polypropylene having an average molecular weight of 1,000 and 2 g of stearic acid were dispersed and dissolved in 96 g of triene.

This solution was applied to the Type 1 polyester wire 10a according to Comparative Example 2.
It was coated and baked on mfl.

The resulting self-lubricating enameled wire had a good appearance, did not peel off even when rubbed with a fingernail, and had a static friction coefficient of 0.07 to 0.08.

[Example 2] Polypropylene 2.9 with an average molecular weight of 4,000. Comparative Example 2: 2g of beeswax dispersed and dissolved in 96g of triene
Baked according to.

The static friction coefficient of the obtained wire was 0.04 to 0.05.

[Example 3] 2 g of polypropylene with an average molecular weight of 4,000 1 soybean oil 2
g was dispersed and dissolved in 96 g of triene and baked in accordance with Comparative Example 2.

The static friction coefficient of the obtained wire was 0.05 to 0.06.

[Example 4] 2 g of polypropylene having an average molecular weight of 4,000 and 2 g of stearylamide dispersed and dissolved in triene 969 were baked in accordance with Comparative Example 2.

The obtained static friction coefficient was 0.06 to 0.07.

[Comparative Example 5].

Comparative Example 2: 2 g of polypropylene with an average molecular weight of 30,000 and 2 g of beeswax were dispersed and dissolved in 96 g of triene.
The coefficient of static friction of the two wires baked according to the method is 0.0.
It was 4-0.05.

In all examples, the coefficient of static friction is improved,
Winding workability was also good.

According to the present invention, since the lubricity of the enamel film is improved, mechanical damage during automatic winding is reduced, layer short defects are prevented, and the reliability of the coil is significantly improved.

In addition, since the lubricity is improved, the coil insertion force is improved,
Since the enameled wires are tightly wound, the coil space factor is improved.

Since polypropylene is hydrophobic, it prevents moisture from entering and improves water resistance.

Compared to those overcoated with nylon to reduce mechanical damage during automatic winding, the liquid groove properties with treated varnish are improved, and because it is a simple double coating, it can be manufactured in one step and mass production is easy.

In the present invention, in order to improve the lubricity, a thin film is formed on the enamel film using a lubricant modified with polypropylene.
A similar effect can be obtained by applying and baking a lubricant containing 0 phr of this lubricant.

The same effect can also be obtained by double coating by applying and baking a normal enamel varnish and then applying and baking a varnish to which this lubricant has been added.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an enameled wire according to an embodiment of the present invention, in which a thin film of low-molecular polypropylene modified with higher fatty acids is formed on an enamel film. 1: Insulated wire, 2: Metal conductor, 3: Enamel film, 4:
Polypropylene and higher fatty acids and/or higher fatty acid derivatives.

Claims (1)

[Scope of Claims] 1 A metal conductor and an insulating film provided on the outer periphery of the metal conductor as an electrical insulator, and an insulating film having an average molecular weight of 1,000 to 1,000 on the insulating film.
30,000 and a thermosetting point of 170°C or less, and a thin lubricating layer made of one type or a mixture of one or more types of higher fatty acids or their derivatives. An insulated wire characterized by: 2 Higher fatty acids have the general formula CH3(CH2)nC00H1 (
In the formula, n is an integer of 10 to 28. ) The insulated wire according to claim 1, which is a saturated fatty acid represented by: The insulated wire according to claim 1, wherein the higher fatty acid derivative is a higher fatty acid alumide represented by the general formula R-CONH2 (wherein R is an alkyl group having 12 to 29 carbon atoms). 4. The insulated wire according to claim 1, wherein the higher fatty acid derivative is a higher fatty acid ester derived from a higher fatty acid and a higher aliphatic alcohol, or a wax containing these. 5. The insulated wire according to claim 1, wherein the higher fatty acid derivative is a vegetable oil containing esters derived from unsaturated resin acids such as oleic acid, linoleic acid, and lyluic acid and glycerin. 6. The insulated wire according to claim 1, wherein the lubricating thin film has a thickness of 2 microns or less.