JPH01309208A - Insulator coated composite wire - Google Patents

Abstract

PURPOSE:To eliminate the lowering of the AC withstanding voltage of a coated wire even under the impregnation of resin by specifying the adhesion strength between the biaxially oriented polyphenylene sulfide film to be coated on a bundle of element wires and the resin to be impregnated in the film. CONSTITUTION:When a bundle of element wires consisting of insulator coated wire is coated further with a biaxially oriented polyphenylene sulfide film and impregnated with resin, the adhesion strength between the biaxially oriented polyphenylene sulfide film and the resin to be impregnated in the film is made to be higher than 30g/cm, preferably higher than 40g/cm. Here, the adhesion strength is defined as the value measured at peel velocity of 200mm/min and peel angle or 90 degree. Contrary, when the adhesion strength is lower than 30g/cm, the AC withstanding voltage of the coated wire is lowered significantly by the impregnation of resin. Thereby the lowering of the AC withstanding voltage, one of the demerits of the impregnated composite wire, can be eliminated to obtain a high AC withstanding voltage.

Description

[Detailed description of the invention] The present invention relates to an electric wire coated with an insulating material.

[Prior Art] Biaxially oriented PPS films have been known as films that have well-balanced properties such as heat resistance, electrical properties, heat and humidity resistance, and mechanical properties.

It is also known from JP-A-55-35459 that the film is used as an electrical insulator (1 size).

Also known is an electric wire (hereinafter sometimes referred to as a composite electric wire) having a structure in which a thin insulator is further wound and coated around the outer periphery of an assembly in which a plurality of wires made of conductors coated with an insulator are bundled together.

[Problems to be Solved by the Invention] However, in order to obtain an electric wire with excellent heat resistance, a PPS film is used for insulation around the outer periphery of the above-mentioned combined electric wire, and the electrical insulation is further stabilized, especially the AC withstand voltage is stabilized. When impregnated with a resin such as an epoxy resin with the aim of increasing and improving the AC voltage, there was a problem in that the AC withstand voltage was significantly lowered. Therefore, the range of application of the above-mentioned cables and coils using biaxially oriented PPS films has been severely limited.

The present invention uses a biaxially oriented PPS film with excellent heat resistance, electrical properties, mechanical properties, etc. as an insulating material, and aims to provide an insulating material-coated composite wire that does not reduce AC withstand voltage even when impregnated with resin. It is something.

[Means for Solving the Problems] The present invention provides a conductor and a bundle of wires made of an insulating material for covering the conductor, which is further coated with a biaxially oriented polyphenylene sulfide film, An insulating material-coated composite wire impregnated with a resin is characterized in that the adhesive force between the biaxially oriented polyphenylene sulfide film and the impregnated resin is 30 g/cm or more.

In the present invention, a conductor is a substance that easily conducts electricity, and metals such as copper, iron, and aluminum are most commonly used.

The shape of the conductor is not particularly limited, but it is most common to have a circular or square cross section. In addition, when the thickness is circular in cross section, the diameter is preferably 2M to 80m.

When the cross section is a quadrilateral, a rectangle with − sides of 1 to 20 m is preferable. The length is not particularly limited.

In the present invention, the insulating material used for the wire is not particularly limited, but it is preferably heat resistant. Examples include single substances or composites of polyester, polyphenylene sulfide, aromatic polyimide, fluorine-based resins, films, insulating paper, heat-resistant paper, mica, and the like. The insulating material covers the conductor with a tube coating, a coating, a winding coating, or the like.

Furthermore, it may be impregnated with another resin.

More preferably, a biaxially oriented PPS film is wound and coated.

Furthermore, the biaxially oriented polyphenylene sulfide film (hereinafter sometimes abbreviated as PP5-BO) used in the present invention is obtained by melt-molding a resin composition containing poly-p-phenylene sulfide as a main component. Sea 1 ~ shape,
This film is biaxially stretched and heat treated.

Moreover, the thickness of the film is preferably in the range of 3 to 200 microns.

In the present invention, the resin composition containing poly-p-phenylene sulfide as a main component (hereinafter sometimes abbreviated as PPS-based composition) refers to a composition containing 90% by weight or more of poly-p-phenylene sulfide. .

If the content of PPS is less than 90% by weight, the crystallinity and thermal transition degree of the composition will be low, and the characteristics of the film made of the composition, such as heat resistance, dimensional stability, and mechanical properties, will be impaired.

The remaining less than 10% by weight of the composition is a polymer other than PPS, v! Additives such as organic or organic fillers, lubricants, colorants, and ultraviolet absorbers may be included as long as they do not impede the purpose of the present invention.

The melt viscosity of the resin composition is preferably in the range of 500 to 12,000 poise (more preferably 700 to 10,000 poise) at a temperature of 300° C. and a shear rate of 2001/sec from the viewpoint of film formability.

The melt viscosity of the resin composition is equal to the melt viscosity of the final 1q biaxially oriented poly-p-phenylene sulfide film.

In the present invention, poly-p-phenylene sulfide (hereinafter sometimes abbreviated as PPS) is defined as a group in which 70 mol% or more (preferably 85 mol% or more) of repeating units are represented by the structural formula →()S÷ A polymer consisting of component units. If the content of such components is less than 70 mol%, the crystallinity, thermal transition temperature, etc. of the polymer will be low, impairing the heat resistance, dimensional stability, and mechanical properties that are the characteristics of a film made of a resin composition containing PPS as a main component.

Less than 30 mol% of repeating units, preferably 15 mol%
If the amount is less than 1, there is no problem even if a unit containing a sulfide bond capable of co-assembly is included.

The insulating material coated composite electric wire of the present invention is obtained by wrapping a biaxially oriented PPS film around a bundle of a plurality of the above-mentioned wires.

Wrapped coating is made by slitting the film to an appropriate width to create a tape-like product, and rubbing it in a helical pattern around multiple bundled wires to completely insulate the wires so that they are not exposed. This can be achieved by preserving one's sexuality. The winding coating is generally wound in half or overlapping manner, and it is preferable to twist the winding two or more times from the viewpoint of reliability of electrical insulation.

The insulating material coated composite electric wire of the present invention comprises the above-mentioned biaxially oriented PPS.
The film wrap is further impregnated with resin. Examples of the resin include thermosetting resins such as epoxy resin, silicone resin, acrylic resin, and phenol resin, but it is particularly preferable to use an epoxy resin. Furthermore, it is possible, but rather preferable, for the resin to contain additives such as curing aids and heat stabilizers.

Furthermore, impregnation is performed to completely infiltrate the resin into the gaps between the films of the conductor covered with the above film and between the film and the conductor, and to further stabilize the electrical insulation by completely adhering the conductor. be.

In the insulating material-coated composite wire of the present invention, the two
The adhesive strength between the axially oriented PPS film and the resin used for impregnation is 309/an or more (preferably 40 g/c
The adhesive force referred to here must be
This refers to the value measured at a peeling angle of 90 degrees and a peeling speed of 200 m/min. If the adhesive strength is less than 3 OL3/cm, the AC withstand voltage will be significantly reduced due to resin impregnation.

The insulating material-coated composite wire of the present invention may be bent and deformed into various shapes.

Next, a method for manufacturing the insulating material-coated composite wire of the present invention will be described.

PPS used in the present invention is obtained by reacting an alkali sulfide and paradihalobenpine in a polar solvent at high temperature and high pressure. In particular, sodium sulfide and balajichlorobenzene are
- It is preferable to carry out the reaction in an amide type high boiling point polar solvent such as medylpyrrolidone.

In this case, in order to adjust the degree of polymerization, it is most preferable to add a so-called polymerization aid such as a strong alkali or an alkali metal carboxylic acid salt, and to carry out the reaction at 230 to 280'C. The pressure within the polymerization system and the polymerization time are appropriately determined depending on the type and amount of the auxiliary agent used, the desired degree of polymerization, etc. The resulting powdered or granular polymer is washed with water and/or a solvent to separate by-product salts, polymerization aids, unreacted additives, and the like.

In order to form this polymer into a biaxially oriented film, the resin is melted by an extruder and cast onto a metal drum from a die at a constant ω constant rate, followed by rapid cooling to form a non-oriented, amorphous sheet. Then, the sheet is biaxially stretched and heat treated by a well-known method. Stretching is carried out at 90 to 110'C in both the longitudinal direction and the width direction in a range of 3.0 to 4.5 times. Heat treatment ranges from 240℃ to melting point, fixed length or 15%
Perform the following restricted contractions for 1 to 60 seconds. Additionally, it may be relaxed in one or two directions to improve the thermal dimensional stability of the film.

The method of rubbing the above-mentioned biaxially oriented PPS film around a plurality of bundled electric wires in a helical shape is to slit the film to a width of, for example, 20 shoes to create a tape-like product, and then rub the film around the electric wires. Use a winding machine or the like to cover the material by wrapping it in a half-overlap or half-overlap manner. Usually, the above-mentioned winding coating is carried out in two to five layers.

The subsequent resin impregnation is performed using a heat-resistant curing resin such as epoxy resin or silicone resin. A curing aid, heat stabilizer, etc. are added to the above resin, and the mixture is placed in a vacuum impregnation tank. Then, a biaxially oriented PPS film is wound around a plurality of bundled electric wires in the resin. The coated material is charged and impregnated at a temperature in the range of room temperature to 50° C. while degassing in vacuum. The resin-impregnated electric wire thus obtained has a temperature range of 0°5 to 3°C at a temperature ranging from 100°C to 200°C
It is heat cured under conditions of 0 hours.

Further, in order to improve the adhesion between the film and the impregnated resin, at least one side of the film is subjected to electrical surface treatment such as corona discharge treatment or plasma treatment or primer coating treatment. Corona discharge treatment is 2000 J
It is preferable to carry out the treatment at a treatment intensity in the range of # to 8000 J/rd. In addition, the plasma treatment is performed in a gas atmosphere such as Ar or Co2.02. It is particularly preferred to carry out the reaction at a pressure of less than 1000 m. Further, the primer coating process uses an epoxy-based, acrylic-based, silicone-based resin, etc., and is applied by a method such as a gravure roll method or a reverse coater method. The coating thickness is preferably within the range of 0.1 to 5.0 μm. Furthermore, the above electrical surface treatment and primer coat joint may be performed in combination of two or more types of treatments. Primer coating is particularly preferred to achieve the objectives of the present invention.

[Effects of the Invention] Since the electric wire of the present invention has the above-described structure, it is coated and insulated with a biaxially oriented PPS film, and the decrease in AC withstand voltage, which was a drawback of the conventional composite electric wire impregnated with a resin, is eliminated. The resulting wire has a higher AC withstand voltage than a wire without impregnation.

[Function] Although it is not clear why the present invention prevents a decrease in AC withstand voltage and conversely improves it, corona discharge occurs between the films by increasing the adhesive strength between PP5-BO and the impregnated resin. This is thought to be because the insulation breakdown due to corona deterioration is prevented.

[Applications] The electric wire of the present invention can be used not only for power and signal cables but also for coils of equipment requiring F-class insulation such as power generation buildings, electric motors, vehicle motors, and transformers.

Furthermore, since the biaxially oriented PPS film has excellent radiation resistance and cryogenic properties, it is also suitable for parts that require cold resistance and radiation resistance, such as the coil for a nuclear fusion reactor in a nuclear fusion device.

[1S property measurement method and evaluation basis Q] (1) Adhesive strength PP5-BO is wrapped around multiple bundled wires and resin-impregnated wires are coated with PP5-801J (two or more layers overlapped). Take out the part and measure the adhesive force using a shopper.The adhesive force measurement conditions are that the peeling angle is 90 degrees.
degree J: sea urchin, peeling speed is 20 o#/min
Te 35 le.

(2) Measurement of AC withstand voltage Wrap PP5-BO around multiple bundled wires, cut the resin-impregnated wires to a length of 300 m, and place aluminum foil (one part µm thick) in the center of the lean pull. > to a width of 100m.Measure the withstand voltage between the conductor part of the wire and the aluminum foil.The withstand voltage is measured using an AC power source at 750 m.
This is carried out at a boosting rate of V/sec.

[Example] Next, the present invention will be explained in detail by giving examples.

Example 1 (1) Biaxially oriented PPS film 50 μm thick biaxially oriented PPS film “Torelina”, type 3000 manufactured by Toshi 2 was used.

(PPS-80-1> PPS-8
0-2>, the following adhesive was applied.

Adhesive: "Hisole" T [5401 solid content concentration 40
Weight% (manufactured by Toshimagari) Mixing ratio of main agent/curing agent: % Solvent: Methyl ethyl ketone Adjust the above adhesive to have a solid content of 20% by weight, and apply it to both sides of PP5-BO-2 using a gravure roll method. did. The drying conditions were 100'C for 3 minutes, and the coating thickness was adjusted to 1.5 μm/side after drying. (
PPS-BO-3) (2) Preparation of electric wire (single wire) A 4 m square copper rod (length 300 m) was prepared and washed with acetone.

Next, PP5-BO-3 was slit to a width of 1,571,111 mm, and rubbed on the copper rod with half overlap, and the rubbing was repeated 3 times.

(3) Electric wire (bundling of multiple wires) PPS-BO-3 was slit into a width of 20 m to create a tape-like wire.

Next, bundle the four electric wires created in (2) above, and
The O-3 tape was rubbed with half overlap, and the rubbing was roughly repeated three times.

(4) Resin impregnation The following epoxy resin was used as the impregnating resin.

Epoxy resin ("Epicoat" 828 manufactured by Yuka Shell Epoxy > 100 parts Acid anhydride ("NMA" manufactured by Vetrochemical) 70 parts Tertiary amine ("Dydocral" 11D-8CC-4
3 Parts manufactured by Petrochemical The above composition was stirred and mixed for 1 hour while keeping the temperature at 30'C. Furthermore, the above epoxy resin was placed in a glass tube that could be evacuated.

On the other hand, after heat-treating the wire rubbed with PP5-BO-3 prepared in (3) at a temperature of 120'C for 2 hours,
The temperature was lowered to 50'C, the product was placed in the above epoxy resin, and a cycle of vacuuming for 5 minutes and pressure release for 10 minutes was performed three times. The resin-impregnated electric wire thus obtained was 80%
The impregnating resin was heat cured under the conditions of 5 hours at 120'C, 2 hours at 160'C.

Example 2 (1) Preparation of bidirectionally oriented PPS film The following adhesive was applied to both sides of PP5-BO-2.

Adhesive: "Kemi~Epoxy" TE5920 solid content concentration 30% by weight (manufactured by Toshi ■) Mixing ratio of main agent/curing agent: 15/100 Solvent: Mixed solvent of methanol, toluene, xylene, Medyl Celsolve The above resin composition was adjusted to have a solid content concentration of 20% by weight, and applied to both sides of PP5-BO-2 using a gravure roll method. The coating conditions are the same as in Example 1. (PPS-
BO-4> (2) Preparation of electric wire and resin impregnation Using PP5-BO-4, an electric wire was prepared under the conditions of Example 1 and immersed in resin.

Example 3 (1) γ1 of biaxially oriented PPS film (PPS-80
A primer coat treatment using the following resin composition was performed on both sides of the sample -2.

(8) Acrylic resin (“Kotax” LK730 solid content 5 solids 9-0 (B) Epoxy resin (“Epicoat” 828 Yuka Shell Epoxy) Mixing ratio (solid content): A/B = 1 5/1 solvent ; Toluene, isopropyl alcohol The above resin composition was adjusted to a solid content concentration of 30% by weight, and P was coated using a gravure roll method.
It was applied to both sides of P5-BO. The drying conditions were 120° C. for 2 minutes, and the coating thickness was adjusted to 1.5 μm/side in terms of drying speed. (This is referred to as PPS-80-5.) (2) Preparation of electric wire and resin impregnation Using PP5-BO-5, an electric wire was prepared under the same conditions as in Example 1, and impregnated with resin.

Preparation of Comparative Examples 1 and 2 Four electric wires with PP5-BO-1 wrapped and coated around the conductor were bundled under the conditions of Example 1, and then PPS-80 was wrapped around the wires.
-1 was wound and coated (before being impregnated with resin) as Comparative Example 1.

Next, Comparative Example 2 is obtained by impregnating Comparative Example 1 with resin under the conditions of Example 1.

The evaluation results of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.

The evaluation standard was the AC withstand voltage value of Comparative Example 1 before resin impregnation. This is because, when the withstand voltage of the sample is measured, corona is generated violently as the voltage increases, resulting in dielectric breakdown that looks like a tail from a small portion of the insulating film.

Therefore, the actual withstand voltage is considered to be at least higher than the sample.

Next, when Comparative Example 2 was measured, the withstand voltage was much lower than that of the above-mentioned sample, clearly showing the conventional problem that the withstand voltage was significantly lowered due to resin impregnation.

On the other hand, it can be seen that the electric wires of Examples 1 to 3 of the present invention not only have no decrease in withstand voltage, but also have further improved voltage resistance. Also,
Adhesion strength between impregnated resin and biaxially oriented PPS film is 30
It is well understood that the object of the present invention cannot be achieved unless it is at least g/cm.

Table 1

Claims (1)

[Claims] (1) In an insulating material-coated electric wire formed by bundling a plurality of wires made of a conductor and an insulating material for covering the conductor, the wire is further covered with a biaxially oriented polyphenylene sulfide film and impregnated with a resin. , the adhesive strength between the biaxially oriented polyphenylene sulfide film and the impregnated resin is 30
An insulating material-coated composite electric wire characterized in that the wire has a wire of at least g/cm.