JPH01309207A - Insulator coated 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 the conductor and the resin to be impregnated in the film. CONSTITUTION:The adhesion strength between the biaxially oriented polyphenylene sulfide film to be coated on the conductor of an insulator coated wire 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 defied as the value measured at peel velocity of 200mm/min and peel angle of 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 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 electrically insulating material.

[Problem to be solved by the invention] However, it is possible to wrap the above-mentioned film around a conductor to further stabilize the electrical insulation, especially the AC withstand voltage,
Moreover, when impregnated with a resin such as epoxy resin for the purpose of improving the voltage, there was a problem in that the AC withstand voltage was significantly lowered. Therefore, the scope of application of cables and coils using electric wires using biaxially oriented PPS films as insulation coatings has been severely limited.

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

[Means for Solving the Problems] The present invention provides a conductor, a biaxially oriented PP for covering the conductor,
The present invention is an insulating material-coated electric wire made of an S film and an impregnated resin, characterized in that the adhesive force between the biaxially oriented PPS film and the impregnated resin is 309/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 2'# to 80 m. When the cross section is a quadrilateral, a rectangle with − sides of 1 to 20 m is preferable. The length is not particularly limited. Further, two or more of the above conductors may be bundled together. The conductor may also be bent and deformed into various shapes.

In addition, the biaxially oriented polyphenylene sulfide film (hereinafter sometimes abbreviated as PP5-BO) used in the present invention is a resin composition containing poly-p-7 ethylene sulfide as a main component. Form into a sheet, 2
It is made of a film that has been axially stretched and heat treated.

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

In the present invention, a 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. say.

If the content of PPS is less than 90% by weight, the crystallinity, thermal transition degree, etc. 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 may contain additives such as polymers other than PPS, inorganic or organic fillers, lubricants, colorants, ultraviolet absorbers, etc., as long as the purpose of the present invention is not impaired. do not have.

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'C1 and a shear rate of 2001/sec in terms of film formability.

The melt viscosity of the resin composition is equal to the melt viscosity of the biaxially oriented poly-p-phenylene sulfide film finally obtained.

In the present invention, poly-p-phenylene sulfide (hereinafter sometimes abbreviated as PPS) means that 70 mol% or more (preferably 85 mol% or more) of repeating units are composed of structural units represented by the structural formula ÷S+. It refers to a polymer. If the content of such components is less than 70 mol%, the crystallinity, thermal transition temperature, etc. of the polymer will be low, and the heat resistance, dimensional stability, mechanical properties, etc., which are the characteristics of a film made of a resin composition mainly composed of PPS, will be deteriorated. cormorant.

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 copolymerizable sulfide bond is included.

The biaxially oriented PPS film of the insulation coating of the present invention is wrapped around the conductor. Wrapped covering means slitting the film to an appropriate width to create a tape-like product, and rubbing it around the conductor in a spiral pattern to completely cover the conductor so that it is not exposed and maintain electrical insulation. That's it. The winding coating is generally wound in half or overlappingly, and it is preferable to overlap the winding two or more times from the viewpoint of reliability of electrical insulation.

The insulating material coated electric wire of the present invention is obtained by further impregnating the wound coating of the biaxially oriented PPS film with a resin.

Examples of the resin include thermosetting resins such as epoxy, silicone, acrylic, and phenol resins, but it is preferable to use epoxy resins.

Furthermore, it is possible, but rather preferable, for the resin to contain additives such as curing aids and heat stabilizers.

Impregnation is carried out in order to completely infiltrate the resin into the spaces between the films of the conductor covered with the above-mentioned film and between the film and the conductor, thereby further stabilizing the electrical insulation.

2Nl wound and coated in the insulating material coated electric wire of the present invention
The adhesive force between the oriented PPS film and the resin used for impregnation is 30'g/cm or more (preferably 40'g/cm).
The adhesive strength referred to here means that the peeling angle is 90 degrees and the peeling speed is 200 m/min.
The value measured at The adhesive force is 30'; J/c
If it is less than m, the AC withstand voltage will be significantly lowered due to resin impregnation.

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

PPS used in the present invention is produced by reacting an alkali sulfide and paradihalobenzene in a polar solvent at high temperature and pressure. In particular, it is preferable to react sodium sulfide and balajichlorobenzene in an amide-based high-boiling polar solvent such as N-methylpyrrolidone.

In this case, in order to adjust the degree of polymerization, it is most preferable to add a 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 of 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 lubricating salts, polymerization aids, unreacted monomers, and the like.

In order to form this polymer into a biaxially oriented film, the resin is melted using an extruder and quantitatively cast onto a metal drum through a die and rapidly cooled 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. In addition, in order to improve the thermal dimensional stability of the film, it may be relaxed in one or two directions.Further, in order to improve the adhesion between the film and the impregnating resin, at least one side of the film may be subjected to corona discharge. treatment, electrical surface treatment such as plasma treatment or Pry-Foucault 1~ treatment. Corona discharge treatment is from 2000J# to 8000J/
It is preferable to carry out the treatment at a treatment intensity within the range below. In addition, plasma processing is performed in a gas atmosphere such as Ar, CO2, 02, etc.
Particularly preferred is a pressure of 0 Torr or less. 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. Painting [Thickness is 0.
It is preferably within the range of 1 to 5.0 μm. Further, the above-mentioned electrical surface treatment and primer coating treatment may be performed in combination of two or more types. Primer coating is preferred to achieve the objectives of the present invention.

The method of rubbing the above-mentioned biaxially oriented PPS film around the conductor rod in a helical shape is to slit the film to a width of, for example, 20 feet to create a tape-like piece, and then wrap the film around the conductor in an overlapping manner. , Z wheel winding, etc., using a winding machine or the like to wrap and coat. 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, a heat stabilizer, etc. are added to the above resin, and the mixture is placed in a vacuum impregnation tank. Next, an electric wire coated with a biaxially oriented PPS film wrapped around a conductor is placed in the resin. ,At normal temperature~
Impregnation with vacuum degassing at a temperature in the range of 50°C. The resin-impregnated electric wire made in this way has a length of 100'
It is heat cured at a temperature in the range of C to 200' C for 0.5 to 30 hours.

[Effects of the Invention] Because the electric wire of the present invention has the above-mentioned structure, it is coated and insulated with a biaxially oriented PPS film, which solves the drawback of the conventional resin-soaked electric wire, which is that the AC withstand voltage rarely decreases. The resulting wire has a higher AC withstand voltage than impregnated wire, and has excellent heat resistance and flame retardancy.

[Function] It is not clear why the present invention prevents a decrease in AC withstand voltage, or conversely improves it, but by increasing the adhesive strength between PP5-BO and the impregnated resin, This is thought to be because discharge becomes less likely to occur and dielectric breakdown due to deterioration of the roller thickness is prevented.

[Applications] The insulating material-coated wire of the present invention can be used not only for power and signal cables, but also for coils of equipment that requires class F insulation, such as generators, motors, vehicle generators, and transformers. be able to.

Furthermore, since biaxially oriented PPS films have excellent radiation resistance and cryogenic properties, they are also suitable for parts that require cold resistance and radiation resistance, such as coils for nuclear fusion reactors in nuclear fusion devices.

[Method for measuring properties and criteria for evaluation] (1) Adhesive strength A part where two or more layers of PP5-BO are overlapped is taken out from a rod coated with PP5-BO @ wound around a conductor and impregnated with resin, and the part where two or more layers of PP5-BO overlap is taken out and Measure the adhesive strength. The adhesive strength was measured under conditions such that the peeling angle was 90 degrees and the peeling speed was 200 m/min.

(2) Measuring AC withstand voltage Wrap PP5-BO around the conductor, cut the resin-impregnated rod into a length of 300m++, and rub the center of the sample with aluminum foil (18μm thick) to a width of 100s. . Measure the withstand voltage between the conductor and the aluminum foil. The measurement of withstand voltage is performed using an AC power source at a boost rate of 750 V/sec.

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

Example 1 (1) Preparation of biaxially oriented PPS film.
A thick biaxially oriented PPS film was used.

(It is referred to as PPS-BO-1.) Also, corona treatment is applied to both sides of the film and PP5-B
O-2) and the following adhesive was applied.

Adhesive 2 “Hisole” Ding E5401 Solid content concentration 40% by weight (manufactured by Toshiku Co., Ltd.) Mixing ratio of main agent/curing agent: % Solvent: Methyl cellosolve Adjust the above adhesive to have a solid content concentration of 200% by weight Then, it was applied to both sides of PP5-BO-2 using a gravure roll method. The drying conditions were 100'C for 3 minutes, and the coating thickness was adjusted to 1.5 μm/side after drying. (
Named PPS-BO-3. ) (2) Copper round rod (300# in length) for 10 s of winding coating around the conductor was prepared and cleaned with acetone.

Next, a tape-like product was prepared by slitting PP5-BO-3 to a width of 20 m, and the above-mentioned copper rod was rubbed with the film half overlapped, and the rubbing was repeated three times.

(3) 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 Petrochemical) 70 parts Tertiary amine (“Guidoclar” HD-He CC-43 manufactured by Petrochemical) 3 parts The above composition was stirred and mixed for 1 hour while keeping the temperature at 30° C. Further, the above epoxy resin was put into a glass tube that could be evacuated.

On the other hand, the copper rod rubbed with PP5-BO-3 prepared in (2) was heat treated at 120°C for 2 hours.
The temperature was lowered to 50°C and poured into the above epoxy resin,
A cycle of 5 minutes of vacuum and 10 minutes of pressure release was performed three times.

The resin-impregnated electric wire thus obtained was heated at 80°C.
The impregnated resin was thermally cured under the conditions of 5 hours at 120'C, 2 hours at 160'C, and 5 hours at 160'C.

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

Adhesive: “Chemit Eboxy” Ding E5920 solid content 30% solids (manufactured by Toshi ■) Base resin/curing agent mixture ratio: 15/100 Solvent: Mixed solvent of methanol, toluene, xylene, methylcellosolve The resin composition was adjusted to have a solid content of 200 times 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-
Named as 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 impregnated with resin.

Example 3 (1) Preparation of biaxially oriented PPS film Both surfaces of PP5-BO-2 were subjected to the following primer coating treatment.

(A) Acrylic resin (“Kotax” LK730 solid content 5 solid content 5) (B) Epoxy resin (“Epicoat” 828 Yuka Shell Epoxy) Mixing ratio (solid content): A/B = 15/1 Solvent: Toluene, Isopropyl alcohol The above resin composition was adjusted to have a solid content of 30% by weight and was coated on both sides of PP5-BO-2 using a gravure roll method for 15 minutes.Drying conditions were 120'C for 2 minutes. The coating thickness was adjusted to 1.5 μm/side after drying.The obtained primer coated film had good tackiness.

(This is referred to as PPS-BO-5.) (2> Preparation of electric wire and resin impregnation Using PPS-80-5, an electric wire was prepared under the same conditions as in Example 1 and impregnated with resin.

Preparation of Comparative Examples 1 and 2 PPS-80-1 was wound and coated under the same conditions as in Example 1. (Comparative Example 1) Next, a sample was prepared by impregnating the sample of Comparative Example 1 with resin under the conditions of Example 1. (Comparative Example 2) 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 the resin was destroyed. This is because, when the withstand voltage of the υ sample is measured, as the voltage increases, corona is generated violently, causing dielectric breakdown that appears as a trail from the damaged portion of the insulating film.

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

Next, looking at Comparative Example 2, the withstand voltage is much lower than that of the above-mentioned samples, and the conventional problem that the withstand voltage is significantly lowered due to resin impregnation is clearly understood.

On the other hand, it is clearly seen that the insulating material-coated wires of Examples 1 to 3 of the present invention not only have no decrease in withstand voltage but also have a further improvement. It is also clear that the object of the present invention cannot be achieved unless the adhesive strength between the impregnated resin and the biaxially oriented PPS film is 30 g/cm or more.

Claims (1)

[Claims] (1) An insulating material-coated electric wire consisting of a conductor, a biaxially oriented polyphenylene sulfide film for covering the conductor, and an impregnated resin, wherein the adhesive force between the biaxially oriented polyphenylene sulfide film and the impregnated resin is 30 g/ An insulating material-coated electric wire characterized by having a length of 1 cm or more.