JP6891887B2 - Coil for rotary electric machine, manufacturing method of coil for rotary electric machine, mica tape, cured product of mica tape and insulator - Google Patents

Description

The present invention relates to a coil for a rotary electric machine, a method for manufacturing a coil for a rotary electric machine, mica tape, a cured product of mica tape, and an insulator.

A coil used in a rotating electric machine such as a generator or an electric machine (hereinafter, also simply referred to as a coil) generally has a coil conductor and an insulating layer arranged on the outer periphery of the coil conductor in order to insulate the coil conductor from the external environment. doing. As a material for forming an insulating layer, an insulating material using mica called mica tape is known. The mica tape is generally mainly composed of a lining layer containing a lining material and a mica layer containing mica. The mica tape is impregnated with a resin component in a state before being wound around the insulated body or after being wound around the insulated body, and the insulating layer is formed by curing the resin component.

On the other hand, in the field of generators and the like that employ an indirect cooling method in which hydrogen gas or air is passed through the outside of the coil, high thermal conductivity of the insulating layer provided on the outside of the coil is desired. As one of the methods for increasing the thermal conductivity of the insulating layer, there is a method of incorporating an inorganic filler in the backing layer of the mica tape forming the insulating layer. For example, Patent Document 1 describes a mica tape having improved thermal conductivity by incorporating boron nitride particles as an inorganic filler in the backing layer.

International Publication No. 2015-053374

Mica contained in the mica layer is a flaky inorganic substance having excellent electrical insulating properties, and the larger the amount of mica contained in the mica layer, the higher the insulating effect tends to be. On the other hand, if the amount of mica is increased, the thickness of the mica tape may increase, making it difficult to wrap the mica tape around the insulator, or voids, cracks, etc. may occur in the formed insulating layer.
In addition, if the content of the inorganic filler is increased to improve thermal conductivity, the mica tape becomes hard, wrinkles, cracks, etc. are likely to occur when wound around the coil, delamination of the insulating layer, residual voids, etc. occur. As a result, the insulation reliability of the insulating layer may decrease.
Further, if the proportion of the mica layer in the mica tape is increased in order to improve the electrical insulation property, the proportion of the backing layer containing the inorganic filler may decrease, and the thermal conductivity of the insulating layer may decrease.
Therefore, the development of a coil having an insulating layer having excellent electrical insulation while maintaining high thermal conductivity is awaited. In addition, the development of mica tape capable of forming an insulating layer having excellent electrical insulation while maintaining high thermal conductivity is awaited.

In view of the above circumstances, it is an object of the present invention to provide a coil for a rotary electric machine having an insulating layer having excellent electrical insulation while maintaining high thermal conductivity, and a method for manufacturing the coil. Another object of the present invention is to provide a mica tape capable of forming an insulating layer having excellent electrical insulation while maintaining high thermal conductivity, a cured product of mica tape, and an insulator using the mica tape.

Specific means for solving the above problems are as follows.
<1> A coil conductor and an insulating layer arranged on the outer periphery of the coil conductor are provided, the insulating layer contains mica tape, and the mica tape includes a mica layer containing mica, a backing material, and an inorganic filler. anda backing layer containing, by mass per 1 m ² of the mica layer is ^{110g / m 2 ~160g / m 2} , the rotary electric machine coils.
<2> The coil for rotating electricity according to <1>, wherein the content of the mica in the mica layer is 45% by volume or less.
<3> In the mica tape, the proportion of mica that does not pass through the JIS standard sieve having a nominal opening of 2.8 mm is less than 45% by mass of the total mica contained in the mica layer, <1> or <2. > Coil for rotary electric machine.
<4> The coil for a rotary electric machine according to any one of <1> to <3>, wherein the mica tape further contains a resin component.
<5> Any of <1> to <4>, wherein the content of the inorganic filler in the mica tape is 20% by volume to 50% by volume of the total volume of the non-volatile content excluding the mica and the backing material. The coil for a rotary electric machine according to item 1.
<6> The coil for a rotary electric machine according to any one of <1> to <5>, wherein the thickness ratio of the mica layer in the mica tape is 30% to 70%.
<7> Any of <1> to <6>, which comprises a step of winding the mica tape around the outer periphery of the coil conductor and a step of forming an insulating layer from the mica tape wound around the outer periphery of the coil conductor. The method for manufacturing a coil for a rotary electric machine according to item 1.
<8> and mica layer containing mica has a backing layer containing a backing material and an inorganic filler, mica tape weight of the mica layer is ^{110g / m 2 ~160g / m 2} .
<9> The mica tape according to <8>, wherein the content of the mica in the mica layer is 30% by volume to 45% by volume.
<10> The mica according to <8> or <9>, wherein the proportion of mica that does not pass through the JIS standard sieve having a nominal opening of 2.8 mm is less than 45% by mass of the total mica contained in the mica layer. tape.
<11> The item according to any one of <8> to <10>, wherein the content of the inorganic filler is 20% by volume to 50% by volume of the total volume of the non-volatile content excluding the mica and the backing material. Mica tape.
<12> The mica tape according to any one of <8> to <11>, further containing a resin component.
<13> The cured product of the mica tape according to <12>, which is obtained by curing the resin component.
An insulator having <14> an insulator and an insulating layer containing a cured product of <13> mica tape arranged on at least a part of the surface of the insulator.

According to the present invention, there is provided a coil for a rotary electric machine having an insulating layer having excellent electrical insulation while maintaining high thermal conductivity, and a method for manufacturing the coil. Further, according to the present invention, there are provided a mica tape capable of forming an insulating layer having excellent electrical insulation while maintaining high thermal conductivity, a cured product of mica tape, and an insulator using the mica tape.

It is the schematic sectional drawing which shows an example of the structure of the mica tape of this embodiment.

Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the components (including element steps and the like) are not essential unless otherwise specified. The same applies to the numerical values and their ranges, and does not limit the present invention.
In the present specification, the term "process" includes not only a process independent of other processes but also the process if the purpose of the process is achieved even if the process cannot be clearly distinguished from the other process. Is done.
In the numerical range indicated by using "~" in the present specification, the numerical values before and after "~" are included as the minimum value and the maximum value, respectively.
In the numerical range described stepwise in the present specification, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. Good. Further, in the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.
In the present specification, the content or content of each component in the composition refers to the content of each component in the composition when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified. It means the total content or content of substances.
In the present specification, the particle size of each component in the composition is a mixture of the plurality of particles existing in the composition unless otherwise specified, when a plurality of particles corresponding to each component are present in the composition. Means a value for.
In the present specification, the term "layer" refers to the case where the layer is formed in the entire region when the region is observed, and the case where the layer is formed only in a part of the region. Is also included.
As used herein, the term "laminated" refers to stacking layers, and two or more layers may be bonded or the two or more layers may be removable.

<Coil for rotary electric machine>
The coil for a rotary electric machine of the present embodiment has a coil conductor and an insulating layer arranged on the outer periphery of the coil conductor, and the insulating layer includes mica tape.
The mica tape, the mica layer containing mica has a backing layer containing a backing material and an inorganic filler, weight per 1 m ² of the mica layer is ^{110g / m 2 ~160g / m 2} .

The coil for a rotary electric machine of the present embodiment has excellent thermal conductivity because the mica tape forming the insulating layer contains an inorganic filler.
Further, according to the study by the present inventors, when ^{the mass of the mica layer of the mica tape forming the insulating layer per 1 m 2} is 110 g / m ² or more, the electrical insulating property of the insulating layer is well maintained, but 110 g. It was found that the electrical insulation property was remarkably lowered when it was less than / m ^{2. On the other hand, when the mass per 1 m 2} of the mica layer of the mica tape forming the insulating layer is 160 g / m ² or less, the wrapability of the mica tape is well maintained, and the insulating layer formed by using the mica tape is electrically insulated. Although it has excellent properties, if ^{the mass per 1 m 2 of} the mica layer exceeds 160 g / m ² , the wrapping property of the mica tape is significantly reduced, and the insulating layer formed by using this has voids, cracks, etc. inside. It was found that sufficient electrical insulation could not be obtained.

The details and preferred embodiments of the mica tape used for forming the insulating layer of the coil of the present embodiment are the same as those of the mica tape of the present embodiment described later. Further, the material, shape, size and the like of the coil conductor used for the coil of the present embodiment are not particularly limited and can be selected according to the application of the coil and the like.

<Manufacturing method of coil for rotary electric machine>
The method for manufacturing a coil for a rotary electric machine of the present embodiment includes a step of wrapping a mica tape around the outer periphery of a coil conductor and a step of forming an insulating layer from the mica tape wound around the outer periphery of the coil conductor.

The method of wrapping the mica tape around the outer circumference of the coil conductor is not particularly limited, and a usual method can be adopted.

The method of forming the insulating layer from the mica tape wound around the outer circumference of the coil conductor is not particularly limited. For example, after wrapping the mica tape around the coil conductor, the mica tape is heated (heat pressed) while being pressurized to allow the resin component contained in the mica tape to flow out of the mica tape in advance to fill the space between the overlapping mica tapes. Then, the resin component is mica by the method of curing this to form an insulating layer (in the case of prepreg mica tape) and the vacuum pressurization impregnation method (VPI) after wrapping the mica tape around the coil conductor. Examples thereof include a method of impregnating a tape and curing it to form an insulating layer (in the case of dry mica tape).

<Mica tape>
The mica tape of the present embodiment has a mica layer containing mica and a lining layer containing a backing material and an inorganic filler (an inorganic filler other than mica, hereinafter simply referred to as "inorganic filler"). mass per 1 m ² of the mica layer is ^{110g / m 2 ~160g / m 2} .

According to the study by the present inventors, the electrical insulation (particularly, the insulation life) of the insulating layer formed from the mica tape is maintained at a good level when ^{the mass per 1 m 2 of} the mica layer is 110 g / m ^{2 or more.} However, it was found that the amount decreased significantly below 110 g / m ^2. On the other hand, the wrapping property around the insulator is maintained at a good level when ^{the mass per 1 m 2 of} the mica layer is 160 g / m ^{2 or less, but the mass per 1 m 2 of} the mica layer is 160 g / m ^2. It was found that in the case of the high heat conductive tape, the thickness of the entire tape increases, so that the thickness is significantly reduced. Therefore, the mass per 1 m ² of the mica layer is in the range of ^{110g / m 2 ~160g / m 2} , was found to be capable of forming an insulating layer excellent in electric insulation while maintaining high thermal conductivity.

Mass per 1 m ² of the mica layer ^is, 110g / ^m 2 ^~160g / m in the case if no particular limits of ^2, can be selected according to the characteristics required of the mica tape. When better electrical insulation properties is required, it is preferable that the mass per 1 m ² of the mica layer is 120 g / ^{m 2} or more, more preferably 130 g / ^{m 2} or more. If better winding resistance is required, it is preferable that the mass per 1 m ² of the mica layer is 150 g / ^{m 2} or less, more preferably 140 g / ^{m 2} or less.

FIG. 1 is a schematic cross-sectional view showing an example of the structure of the mica tape of the present embodiment. As shown in FIG. 1, the mica tape has a mica layer 6 containing mica 4 and a backing layer 5 containing a backing material 2 and an inorganic filler 1. Further, the mica layer 6 and the lining layer 5 may each contain the resin component 3. The resin component 3 may be contained in both the mica layer 6 and the lining layer 5, or may be contained in only one of them. When the mica layer 6 (or the lining layer 5) contains the resin component 3, the resin component 3 may be contained entirely or partially in the mica layer 6 (or the lining layer 5).

The mica tape of the present embodiment is a mica tape (prepreg mica tape) used in a method of winding a mica tape around an insulator and then curing a resin component contained in the mica tape in advance to form an insulating layer. Alternatively, it may be mica tape (dry mica tape) used in a method of forming an insulating layer by curing a resin component to be impregnated after being wound around an insulator.

(Mica)
The type of mica contained in the mica layer is not particularly limited. Examples thereof include unfired hard mica, fired hard mica, unfired soft mica, fired soft mica, synthetic mica and flake mica. Among these, unfired hard mica is preferable from the viewpoint of adhesiveness between mica and the resin component.

One type of mica may be used alone, or two or more types may be used in combination. When two or more types of mica are used in combination, for example, two or more types of mica having the same component but different particle sizes are used, two or more types of mica having the same particle size but different components are used, and the average particle size and components are used. There are cases where two or more types of mica with different values are used.

The size (particle size) of mica is not particularly limited. From the viewpoint of electrical insulation, the proportion of mica that does not pass through the JIS standard sieve having a nominal opening of 2.8 mm is preferably less than 45% by mass, and is 30% by mass or less of the total amount of mica contained in the mica layer. Is more preferable, and 20% by mass or less is further preferable.

It is not always clear why mica tends to have better electrical insulation when the proportion of mica that does not pass through a JIS standard sieve with a nominal opening of 2.8 mm is less than 45% by mass, but for example, the mica layer is relatively By containing a large amount of small mica pieces, the resin component sufficiently fills the space between the mica pieces and suppresses the generation of voids in the mica layer. It is conceivable that the peeling between the mica tapes caused by the above is suppressed.

By reducing the proportion of mica that does not pass through the JIS standard sieve having a nominal opening of 2.8 mm to less than 45% by mass, the electrical insulation property can be improved without increasing the mass per ^{1 m 2 of the mica layer.} That is, it is possible to obtain good wrapping property by suppressing an increase in the thickness of the mica tape while ensuring the necessary electrical insulation.

From the viewpoint of ensuring sufficient dielectric breakdown electric field strength, the proportion of mica that does not pass through the JIS standard sieve with a nominal opening of 0.5 mm has a particle size of 0.5 mm when sieved using the JIS standard sieve. The ratio of the mica pieces as described above is preferably 40% by mass or more, and more preferably 60% by mass or more of the total amount of mica contained in the mica layer.

The above JIS standard sieve complies with JIS-Z-8801-1: 2006 and corresponds to ISO3310-1: 2000. When ISO3310-1: 2000 is used, it is preferable to apply one having a square mesh shape as in JIS-Z-8801-1: 2006.

The target of sieving is the mica piece in the state before forming the mica layer, or the mica piece obtained from the mica layer (mica paper) before forming the mica tape, from the backing layer of the mica tape. It may be a piece of mica obtained from the mica layer peeled off by using a razor or the like.

When the mica pieces obtained from the mica layer are sieved, 1 g of the mica layer is dispersed in 100 g of methyl ethyl ketone, shaken for 10 minutes, and then centrifuged at 8000 rpm (rpm) for 5 minutes. After removing the supernatant, 100 g of methyl ethyl ketone is added to the remaining solid content, shaken for 10 minutes, and then centrifuged at 8000 rpm (rpm) for 5 minutes. Once again, 100 g of methyl ethyl ketone is added to the remaining solid content after removing the supernatant, shaken for 10 minutes, and then centrifuged at 8000 rpm (rpm) for 5 minutes. After removing the supernatant, 100 g of methyl ethyl ketone is added to 1 g of the remaining solid content, dispersed in a mix rotor for 30 minutes, and shaken for another 10 minutes. Then, while shaking the container, the container is sieved with a JIS standard sieve (JIS-Z-8801-1: 2006, ISO3310-1: 2000, Tokyo Screen Co., Ltd., test sieve) having a predetermined opening.

The content of mica in the mica layer is preferably 45% by volume or less, more preferably 30% by volume to 45% by volume, and even more preferably 30% by volume to 40% by volume. In the case of prepreg mica tape, if the mica content is in this range, the resin flow property when the mica tape is wound and heat-molded is improved, the voids in the tape are reduced, and the electrical insulation property tends to be improved. is there. In the case of dry mica tape, when the content of mica is within this range, the resin impregnation property in the vacuum impregnation step is excellent, the voids are reduced, and the electrical insulation property tends to be improved.

The mica layer may contain a substance other than mica (resin component, organic compound other than the resin component, inorganic compound, etc.). In addition, voids may be present in the mica layer. In the case of dry mica tape, the ratio of voids in the mica layer is preferably set according to the desired resin impregnation amount. For example, it is preferably 55% by volume to 70% by volume.

(Backing material)
The type of lining material is not particularly limited. For example, glass cloth can be mentioned. By using the glass cloth as the backing material, the inorganic filler is taken in between the fibers constituting the glass cloth, and the removal of the inorganic filler tends to be suppressed. In addition, the resin component permeated between the fibers tends to be well integrated with the adjacent mica layer, and the thermal conductivity tends to be improved.

When glass cloth is used as the lining material, it may be a fiber whose part is composed of an organic material. The fiber composed of an organic material is not particularly limited, and examples thereof include fibers such as aramid, polyamide, polyimide, and polyester. When a part of the glass cloth is a fiber made of an organic material, the warp, the weft, or both may be a fiber made of an organic material.

The average thickness of the lining material is not particularly limited. For example, it is preferably 30 μm to 60 μm, and more preferably 45 μm to 50 μm. When the average thickness of the backing material is 30 μm or more, it is suppressed that the backing layer becomes too thin following the thickness of the backing material when the mica tape is pressed, and the decrease in thermal conductivity is suppressed. There is a tendency. When the thickness of the backing material is 60 μm or less, the mica tape can be suppressed from becoming thick, and the mica tape tends to be suppressed from being cut or cracked during the process of winding the mica tape around the insulator.

In the present embodiment, the average thickness of the backing material is the arithmetic mean value of the obtained measured values obtained by measuring the thickness of the backing material at a total of 10 points using a micrometer (MDC-SB, Mitutoyo Co., Ltd.). ..

The lining material may be surface-treated, if necessary. As a method of surface treatment of the backing material, for example, treatment with a silane coupling agent can be mentioned.

(Inorganic filler)
The type of inorganic filler is not particularly limited. For example, silica, boron nitride and alumina can be mentioned. Boron nitride is preferable from the viewpoint of thermal conductivity. Boron nitride exhibits higher thermal conductivity than other inorganic fillers (eg, alumina). Therefore, when the backing layer contains boron nitride, the thermal conductivity of the insulating layer formed from the mica tape tends to be further improved. When the inorganic filler contains boron nitride and an inorganic filler other than boron nitride, the proportion of boron nitride in the inorganic filler is preferably 50% by mass or more, more preferably 70% by mass or more, and 90% by mass. The above is more preferable.

The type of boron nitride is not particularly limited, and examples thereof include hexagonal boron nitride (h-BN), cubic boron nitride (c-BN), and wurtzite type boron nitride. Among these, hexagonal boron nitride (h-BN) is preferable. The boron nitride may be a primary particle of boron nitride formed in a scaly shape or a secondary particle formed by aggregating the primary particles.

The average particle size of the inorganic filler is not particularly limited. For example, in the case of the volume average particle size, it is preferably 1 μm to 40 μm, more preferably 5 μm to 20 μm, and further preferably 5 μm to 10 μm.
When the volume average particle diameter of the inorganic filler is 1 μm or more, the thermal conductivity and the withstand voltage of insulation tend to be further improved, and in the resin impregnation step of impregnating the mica tape with the resin component, the particles of the fine inorganic filler The outflow tends to be suppressed. When the average particle size of the inorganic filler is 40 μm or less, the anisotropy of thermal conductivity due to the anisotropy of the particle shape tends to be suppressed, and the protrusion of the particles of the inorganic filler from the tape surface is suppressed. , The outflow of inorganic filler tends to be suppressed in the resin impregnation step.

The volume average particle size of the inorganic filler can be measured by using, for example, a laser diffraction / scattering type particle size distribution measuring device (Nikkiso Co., Ltd., “Microtrack MT3000II”). Specifically, after the inorganic filler is put into pure water, it is dispersed by an ultrasonic disperser. By measuring the particle size distribution of this dispersion, the particle size distribution of the inorganic filler is measured. Based on this particle size distribution, the particle size (D50) corresponding to the cumulative volume of 50% from the small diameter side is obtained as the volume average particle size.

One type of inorganic filler may be used alone, or two or more types may be used in combination. When two or more kinds of inorganic fillers are used in combination, for example, two or more kinds of inorganic fillers having the same component but different average particle diameters are used, two or more kinds of inorganic fillers having the same average particle size but different components are used, and There are cases where two or more kinds of inorganic fillers having different average particle sizes and kinds are used.

If necessary, the inorganic filler may be surface-treated by a coupling agent, heat treatment or light treatment.
For example, in the case of heat treatment, impurities on the surface of the inorganic filler are removed by heating the inorganic filler at an appropriate temperature (for example, 250 ° C. to 800 ° C.) for 1 hour to 3 hours. Therefore, the affinity when the inorganic filler is mixed with the resin component is improved, the viscosity of the composition containing the inorganic filler and the resin component is lowered, and the coating tends to be easy. Further, the coated surface of the composition tends to have less coating unevenness and unevenness, and the smoothness tends to be improved.

(Resin component)
The mica tape may contain a resin component. The type of resin used as the resin component is not particularly limited. From the viewpoint of curing the mica tape to form an insulating layer, a curable resin is preferable, and a thermosetting resin is more preferable. Examples of the curable resin include epoxy resin, phenol resin, unsaturated polyester resin and silicone resin. Epoxy resin is preferable from the viewpoint of adhesiveness between the mica layer and the lining layer and electrical insulation.

When an epoxy resin is used as the resin component, the epoxy resin includes a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, a naphthalene type epoxy resin, a ring-type aliphatic epoxy resin, and the like. Can be mentioned. Among them, from the viewpoint of heat resistance, phenol novolac type epoxy resin, bisphenol A type epoxy resin and bisphenol F type epoxy resin are preferable.

The epoxy equivalent of the epoxy resin is not particularly limited. For example, it is preferably 130 g / eq to 500 g / eq, more preferably 135 g / eq to 400 g / eq, and even more preferably 140 g / eq to 300 g / eq. The epoxy equivalent is measured by dissolving the precisely weighed epoxy resin in a solvent such as methyl ethyl ketone, adding acetic acid and a tetraethylammonium bromide acetic acid solution, and then potentiometric titration with an acetic acid perchlorate standard solution. An indicator may be used for potentiometric titration.

The number average molecular weight of the resin used as the resin component is not particularly limited. For example, from the viewpoint of fluidity, it is preferably 100 to 100,000, more preferably 200 to 50,000, and even more preferably 300 to 10,000. The number average molecular weight of the resin is a value measured under the following conditions according to a conventional method using a gel permeation chromatography method (GPC).

〔Measurement condition〕
Pump: L-6000 (Hitachi, Ltd.)
Column: TSKgel (registered trademark) G4000HHR + G3000HHR + G2000HXL (Tosoh Corporation)
Column temperature: 40 ° C
Elution solvent: Tetrahydrofuran (Chromatographic stabilizer-free, Wako Pure Chemical Industries, Ltd.)
Sample concentration: 5 g / L (solubilized in tetrahydrofuran)
Injection volume: 100 μL
Flow velocity: 1.0 mL / min Detector: Differential refractometer (RI-8020, Tosoh Corporation)
Molecular Weight Calibration Standard Material: Standard Polystyrene Data Processing Device: GPC-8020 (Tosoh Corporation)

When the mica tape contains a curable resin as a resin component, a curing agent may be contained as a resin component. The curing agent is not particularly limited and can be appropriately selected depending on the type of the curable resin. One type of curing agent may be used alone, or two or more types may be used in combination.
When the curable resin is an epoxy resin, the curing agent can be appropriately selected from the curing agents usually used as the curing agent for epoxy resins. Specific examples thereof include amine curing agents such as dicyandiamide and aromatic diamine; phenol resin curing agents such as phenol novolac and cresol novolac; and acid anhydride curing agents such as alicyclic acid anhydride. When the curable resin is an epoxy resin, the ratio of the curing agent to the epoxy resin should be 0.8 to 1.2 in an equivalent ratio (curing agent / epoxy resin) from the viewpoint of curability and electrical characteristics of the cured product. Is preferable.

(Curing catalyst)
When the mica tape contains a curable resin as a resin component, it may contain a curing catalyst for the purpose of accelerating the curing reaction of the curable resin. The curing catalyst is not particularly limited and can be selected according to the type of curable resin and, if necessary, the curing agent used. Specific examples of the curing catalyst include tertiary amine compounds such as trimethylamine, imidazole compounds such as 2-methylimidazole and 2-methyl-4-ethylimidazole, organic metal salts such as tin, zinc and cobalt, and boron trifluoride. Examples thereof include amine complexes of Lewis acids such as monoethylamine and organic phosphorus compounds such as organic phosphine compounds. The curing accelerator may be used alone or in combination of two or more.
When the mica tape contains a curing catalyst, its content is not particularly limited. For example, when an epoxy resin is used as the resin component, the content of the curing catalyst is generally in the range of 0.01% by mass to 5% by mass with respect to the total amount of the epoxy resin and the curing agent contained as needed. is there.

(Other ingredients)
The mica tape may contain other components other than those described above, if necessary. Examples of other components include coupling agents, antioxidants, antioxidants, stabilizers, flame retardants, thickeners and the like. When the mica tape contains these components, the content thereof is not particularly limited.

<Overall composition of mica tape>
The mica tape of the present embodiment has a mica layer containing mica and a lining layer containing a lining material and an inorganic filler, and may have other layers if necessary. Examples of the other layer include a protective layer (protective film) provided on the outermost surface of the mica tape.

The average thickness of the mica tape (the total thickness of the mica layer and the lining layer) is not particularly limited. For example, the average thickness of the mica tape may be 400 μm or less, preferably 350 μm or less, and more preferably 300 μm or less.

When the mica tape is used as the prepreg mica tape, the average thickness of the mica tape is preferably 300 μm or less, more preferably 290 μm or less, from the viewpoint of wrapability of the mica tape. From the viewpoint of electrical insulation, the average thickness of the mica tape is preferably 120 μm or more, more preferably 150 μm or more, and further preferably 160 μm or more.

When the mica tape is used as a dry mica tape, the average thickness of the mica tape is preferably 220 μm or less, more preferably 190 μm or less, from the viewpoint of wrapability of the mica tape. From the viewpoint of electrical insulation, the average thickness of the mica tape is preferably 120 μm or more, more preferably 140 μm or more, and further preferably 160 μm or more.

The average thickness of the mica layer is not particularly limited. From the viewpoint of the wrapability of the mica tape, the average thickness of the mica layer is preferably 180 μm or less, and more preferably 170 μm or less. From the viewpoint of electrical insulation, the average thickness of the mica layer is preferably 80 μm or more, and more preferably 90 μm or more.

The average thickness of the lining layer is not particularly limited. From the viewpoint of wrapping property of the mica tape, the average thickness of the backing layer is preferably 60 μm or less, and more preferably 50 μm or less. From the viewpoint of the strength of the mica tape, the average thickness of the backing layer is preferably 10 μm or more, and more preferably 20 μm or more.

From the viewpoint of improving the wrapping property of the mica tape, the thickness ratio of the mica layer in the mica tape is preferably 70% or less, and more preferably 60% or less. From the viewpoint of improving the electrical insulation property, the thickness ratio of the mica layer in the mica tape is preferably 30% or more, more preferably 40% or more.
The thickness ratio of the mica layer is a value calculated by (average thickness of mica layer / average thickness of mica tape) × 100.

In the present embodiment, the average thickness of the mica tape (total thickness of the mica layer and the lining layer) is determined by using a micrometer (Mitutoyo Co., Ltd., "MDC-SB") to measure the thickness of the mica tape at a total of 10 points. It is measured and used as the arithmetic mean value of the obtained measured values.

In the present embodiment, the thickness of the mica layer and the lining layer in the mica tape is determined by measuring the thickness of the mica layer and the lining layer in the cross section of the mica tape with a stereomicroscope (for example, Olympus Corporation, “BX51”). Observe 3 places and use the arithmetic mean value.

The content of the inorganic filler in the non-volatile components of the mica tape excluding mica and the backing material is not particularly limited. For example, it is preferably 20% by volume to 50% by volume, and more preferably 25% by volume to 35% by volume of the total volume of the non-volatile content excluding mica and the backing material. When the content of the inorganic filler is 20% by volume or more of the total volume of the non-volatile content excluding mica and the backing material, the thermal conductivity of the insulating layer formed from the mica tape tends to be further improved. When the content of the inorganic filler is 50% by volume or less of the total volume of the non-volatile content excluding mica and the backing material, the filling of the inorganic filler into the resin component tends to be easy.

It is preferable that the backing layer of the mica tape contains boron nitride as an inorganic filler, and the apparent volume of mica is 2.0 to 5.0 times the volume of boron nitride.

When the apparent volume of mica is 5.0 times or less the volume of boron nitride, the thermal conductivity is good. On the other hand, if the apparent volume of mica is 2.0 times or more the volume of boron nitride, cracks and wrinkles of the mica tape are less likely to occur when the mica tape is wrapped around the insulator, and voids and voids are less likely to occur. The decrease in thermal conductivity tends to be sufficiently suppressed. Further, by containing a relatively large amount of boron nitride, the proportion of the backing layer exhibiting a relatively high thermal conductivity that contributes to the thermal conductivity of the entire mica tape tends to increase. The apparent volume of mica is more preferably 3.0 to 4.8 times the volume of boron nitride, and even more preferably 3.2 to 4.0 times.

In the present embodiment, the volume of boron nitride is calculated by, for example, the following method.
On a hot plate, mica tape (1 cm ² minutes) containing boron nitride is decomposed in an aqueous nitric acid solution while irradiating with microwaves to prepare a sample solution for measurement. The mass of boron nitride is determined by spraying this sample solution into plasma, separating and quantifying the boron ions generated in the plasma with a mass spectrometer, and converting it into the amount of boron nitride. Dividing the obtained mass by the specific gravity of boron nitride gives the volume of boron nitride (cm ³ ) ^{per 1 cm 2 of mica tape.}

In the present embodiment, the apparent volume of mica is calculated by, for example, the following method.
The thickness (cm) of the mica layer in the mica tape having an area of 1 cm ^{2 was obtained, and the obtained thickness (cm) x 1 cm 2} was obtained to obtain the apparent volume of mica (cm ³ ) ^{per 1 cm 2} of the mica tape. Become.

The content of the non-volatile content excluding the mica and the backing material in the total mass of the mica layer and the backing layer of the mica tape is not particularly limited. For example, it is preferably 5% by mass to 45% by mass, more preferably 10% by mass to 30% by mass, and further preferably 15% by mass to 20% by mass of the total mass of the mica layer and the lining layer. preferable. When the content of the non-volatile content excluding the mica and the lining material is 5% by mass or more of the total mass of the mica layer and the lining layer, the thermal conductivity tends to be improved more effectively. When the content of the non-volatile content excluding the mica and the backing material is 45% by mass or less of the total mass of the mica layer and the backing layer, the increase in the thickness of the mica tape tends to be suppressed. In addition, the impregnation of varnish tends to proceed during the production of mica tape.

The content of the resin component in the non-volatile components of the mica tape excluding mica and the backing material is not particularly limited. For example, it is preferably 35% by mass to 70% by mass, more preferably 50% by mass to 65% by mass, and 55% by mass to 60% by mass of the total mass of the non-volatile content excluding mica and the backing material. Is even more preferable. When the content of the resin component is 35% by mass or more of the total mass of the non-volatile components excluding the mica and the backing material, the adhesiveness between the backing layer and the mica layer tends to be improved. When the content of the resin component is 70% by mass or less of the total mass of the non-volatile components excluding mica and the backing material, the thermal conductivity tends to be improved.

The content of the resin component in the mica tape is not particularly limited and can be selected according to the application of the mica tape and the like. For example, the content of the resin component may be 40% by mass or less of the total mass of the mica layer and the lining layer, and is preferably 5% by mass to 33% by mass.

When the mica tape is used as the prepreg mica tape, the content of the resin component is preferably, for example, 25% by mass to 33% by mass, and 25% by mass to 30% by mass, based on the total mass of the mica layer and the lining layer. Is more preferable. When the content of the resin component is 25% by mass or more of the total mass of the mica layer and the lining layer, the mica and the inorganic filler from the mica tape are prevented from falling off (powder falling off), and when the mica tape is wrapped around the insulator. As a result of suppressing the occurrence of cracks, breaks, wrinkles, etc. of the mica tape, the decrease in insulation reliability and the decrease in thermal conductivity tend to be suppressed. On the other hand, when the content of the resin component is 33% by mass or less of the total mass of the mica layer and the lining layer, the increase in the thickness of the mica tape is suppressed and good wrapping property tends to be maintained. Further, the resin component tends to be suppressed from flowing out in excess of the volume required to fill the gaps between the overlapping mica tapes in a state where the mica tape is wound around the insulator. As a result, the generation of voids tends to be reduced, and the decrease in insulation reliability tends to be suppressed.

When the mica tape is used as a dry mica tape, the content of the resin component in the mica tape is preferably, for example, 5% by mass to 15% by mass of the total mass of the mica layer and the lining layer, and is 5% by mass. It is more preferably ~ 12% by mass, and even more preferably 8% by mass to 10% by mass. When the content of the resin component is 5% by mass or more of the total mass of the mica layer and the mica layer, the adhesiveness between the mica layer and the mica layer tends to be sufficiently ensured. On the other hand, when the content of the resin component is 15% by mass or less of the total mass of the mica layer and the lining layer, high thermal conductivity tends to be achieved.

In the present embodiment, the content of the resin component in the mica tape is calculated by, for example, the following method.
Mica tape cut into a size of 30 mm in width and 50 mm in length is heated in an electric furnace under the conditions of 600 ° C. and 2 hours, and the mass reduction rate (%) before and after heating is calculated by the following formula. The above steps are performed three times, and the obtained values are obtained as the arithmetic mean value.
Resin component content = {(mass before heating-mass after heating) / mass before heating} x 100

When the mica tape is used as a dry mica tape, the content of the resin component in the mica layer is preferably 15% by mass or less, more preferably 10% by mass or less, based on the total mass of the mica layer. It is more preferably 5% by mass or less, and particularly preferably 0% by mass.

From the viewpoint of electrical insulation, the mica layer preferably contains substantially no inorganic filler. Specifically, the content of the inorganic filler in the mica layer is preferably 3% by mass or less, more preferably 2% by mass or less, and 1% by mass or less of the total mass of the mica layer. Is more preferable, and 0% by mass is particularly preferable.

From the viewpoint of suppressing the decrease in thermal conductivity, it is preferable that the mica layer is substantially free of fibrils. Specifically, the content of fibrils in the mica layer is preferably 1% by mass or less, more preferably 0.5% by mass or less, and 0.1% by mass, based on the total mass of the mica layer. The following is more preferable, and 0% by mass is particularly preferable. In the present specification, the fibrit is a fibrous substance mixed so that the mica layer can stand on its own, and examples thereof include organic fibers such as polyamide and polyimide, and inorganic fibers such as glass fiber.

The mica tape of the present embodiment can be used, for example, to form an insulating layer provided on the outer periphery of an insulated body such as a coil conductor used for a rotary electric coil or the like.

<Manufacturing method of mica tape>
The mica tape of the present embodiment may be produced through any process, and a conventionally known production method can be applied.

As an example of the method for producing mica tape, a step of arranging a backing material on mica paper to prepare a laminate, and a composition (varnish) containing an inorganic filler and a resin component are provided on the laminate. Examples thereof include a step of applying the coating material to the backing material side and a method including the process. The composition may be applied so that the composition applied to the backing material oozes out to the other surface side of the backing material and permeates the whole or a part of the mica paper. If desired, the composition may contain a solvent.

The details and preferred embodiments of the mica, the lining material, the inorganic filler and the resin component used in the above method, and the mica tape produced are as described above. Mica paper is a sheet-like object formed by collecting mica pieces.

<Cured product of mica tape>
The cured product of the mica tape of the present embodiment is obtained by curing the mica tape described above. More specifically, it is obtained by curing a resin component contained in mica tape. The curing method is not particularly limited and can be selected from ordinary methods. The resin component may be contained in the mica tape before being wound around the insulator, or may be impregnated after the mica tape is wound around the insulator.

<Insulation>
The insulator of the present embodiment has an insulator and an insulating layer which is a cured product of the mica tape of the present embodiment which is arranged on at least a part of the surface of the insulated body. The method of forming the insulating layer using the mica tape of the present embodiment is not particularly limited, and a conventionally known production method can be applied. For example, after wrapping the mica tape around the insulator, the mica tape is heated (heat pressed) while being pressurized so that the resin component contained in the mica tape flows out of the mica tape in advance and the overlapping mica tapes are separated from each other. A method of filling and curing this to form an insulating layer (in the case of prepreg mica tape), and a vacuum pressure impregnation method (Vacum Pressure Impregnation, VPI) after wrapping the mica tape around the insulated material to make the resin component. Is impregnated into mica tape and cured to form an insulating layer (in the case of dry mica tape).

When the insulating layer is formed by the vacuum pressure impregnation method, the resin component to be impregnated in the mica tape is not particularly limited. For example, those containing an epoxy resin such as a bisphenol A type epoxy resin and a curing agent such as an alicyclic acid anhydride can be mentioned. For the method of impregnating the resin component in the vacuum pressure impregnation method, the curing conditions after impregnation, the ratio of the epoxy resin to the curing agent, and the like, conventionally known methods, known conditions, and the like can be referred to.

The type of the insulated material in the insulator is not particularly limited, and examples thereof include metal materials (copper, etc.) having the shape of a coil, a rod, a plate, or the like. Specific examples of the insulated body include a coil conductor of a coil for a rotary electric machine.

By using the mica tape of the present embodiment, an insulating layer exhibiting high thermal conductivity can be formed. Therefore, when the insulator of the present embodiment is a coil, when cooling the coil, the hydrogen cooling method or the air cooling method should be adopted even for a coil of a scale that has conventionally adopted the water direct cooling method. It becomes possible to simplify the structure of the coil.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

<Example 1>
(1) Preparation of Maikapepa by dispersing green hard mica in water and mica pieces, and papermaking in the papermaking machine, the mass per 1 m ² was prepared in 110g / m ² Maikapepa (uncalcined hard mica) ..

(2) Preparation of resin varnish Phenolic novolac type epoxy resin as a resin component (Dow Chemical Japan Co., Ltd., trade name "DEN 438"("DEN" is a registered trademark)) 36 .7 parts by mass, boron trifluoride monoethylamine (Wako Pure Chemical Industries, Ltd.) 1.1 parts by mass as a curing catalyst, and methyl ethyl ketone (MEK) (Wako Pure Chemical Industries, Ltd.) 31.1 parts by mass as an organic solvent. And mixed. Then, 31.1 parts by mass of boron nitride (average particle size 5 μm, Denki Kagaku Kogyo Co., Ltd.) was added and further mixed to prepare a resin varnish.

(3) Preparation of prepreg mica tape A glass cloth (Souyo Co., Ltd., "WEA 03G 103", thickness 0.030 mm) is layered on the mica paper as a backing material, and a resin varnish is rolled on the upper surface of the glass cloth. Was applied using. The application was carried out so that the resin component of the resin varnish penetrated the entire mica paper under the glass cloth. The impregnation properties were all good.
At this time, by adjusting the gap width between the roll coater and the glass cloth, the apparent volume of mica was adjusted to 4.65 times the volume of boron nitride. After drying, the laminate of the mica layer and the glass cloth layer (lining layer) was cut so as to have a width of 30 mm to prepare a prepreg mica tape.

(4) Preparation of laminated cured product of prepreg mica tape The number of prepreg mica tapes prepared by the above method required for the measurement of thermal conductivity, the measurement of insulation breakdown electric field strength, and the evaluation of the chargeable deterioration life, which will be described later ( 3 to 16 sheets) were stacked and heat-pressed at 170 ° C. for 1 hour to cure the resin component to prepare a laminated cured product.

<Examples 2 to 6 and Comparative Examples 1 to 2>
The prepreg mica tapes of Examples 2 to 6 and Comparative Examples 1 and 2 were applied in the same manner as in Example 1 except that the amount of mica used was changed so that the mass per 1 m ^{2 of mica paper became the value shown in Table 1.} It was prepared and a laminated cured product was prepared.

<Comparative example 5>
The green hard mica and mica pieces were dispersed in water, and paper making in a paper machine, the mass per 1 m ² was prepared Maikapepa of 240 g / m ² (uncalcined hard mica).
The prepreg mica tape of Comparative Example 5 was prepared in the same manner as in Example 1 except that the obtained mica paper was used, and a laminated cured product was prepared.

<Example 7>
(1) Preparation of dry mica paper The same uncalcined hard mica used for producing mica tape in Example 1 was dispersed in water to form mica pieces, which were made with a paper machine to obtain a mass per ^{1 m 2.} 110 g / m ² mica paper (unbaked hard assembled mica) was prepared.

(2) Preparation of resin varnish 13.1 parts by mass of bisphenol A type epoxy resin (Mitsubishi Chemical Co., Ltd., "Epicoat 828" (general-purpose epoxy)) as a resin component and zinc (II) acetylacetonate (genuine chemical) as a curing catalyst (Co., Ltd.) 3.3 parts by mass and 46.0 parts by mass of methyl ethyl ketone (Wako Pure Chemical Industries, Ltd.) as an organic solvent were mixed. Then, 37.6 parts by mass of boron nitride (average particle size 5 μm) was added as an inorganic filler and further mixed to prepare a resin varnish.

(3) Preparation and Evaluation of Dry Mica Tape A glass cloth (Souyo Co., Ltd., "WEA 03G 103") was placed on the mica paper as a backing material, and a resin varnish was applied to the upper surface of the glass cloth with a roll coater. The coating was carried out so that the resin component of the resin varnish permeated a part of the mica paper under the glass cloth and the mica paper and the glass cloth were adhered with the resin component. After drying, it was cut to a width of 30 mm to prepare a dry mica tape.

(4) Preparation of Laminated Hardened Mica Tape of Dry Mica Tape The number of mica tapes prepared by the above method required for the measurement of thermal conductivity, the measurement of dielectric breakdown electric field strength, and the evaluation of chargeable deterioration life (3). ~ 25 sheets) Stacked and immersed in the impregnated resin, and the resin component was impregnated into the dry mica tape by the vacuum impregnation method. The impregnation properties were all good. Then, heat pressing was performed at 130 ° C. for 2 hours and then at 190 ° C. for 2 hours to prepare a laminated cured product. As the impregnated resin, a bisphenol A type epoxy resin (Mitsubishi Chemical Corporation, Epicoat 828) and a curing agent (Hitachi Kasei Co., Ltd., "HN-5500", methylhexahydrophthalic anhydride) are mixed at a ratio of 1: 1 on a mass basis. A mixture was used.

<Examples 8 to 10, Comparative Examples 3 and 4>
The dry mica tapes of Examples 8 to 10 and Comparative Examples 3 and 4 were applied in the same manner as in Example 7 except that the amount of mica used was changed so that the mass per 1 m ^{2 of mica paper became the value shown in Table 1.} It was prepared and a laminated cured product was prepared.

<Comparative Example 6>
The dry mica tape of Comparative Example 6 was prepared in the same manner as in Example 7 except that the same mica paper as that used in Comparative Example 5 was used, and a laminated cured product was prepared.

<Evaluation>
(1) Measurement of thermal conductivity The laminated cured product produced by the above method is subjected to thermal conductivity (W / (m · K)) using a thermal conductivity measuring device (Hideko Seiki Co., Ltd., “HC-110”). ) Was measured. The number of laminated cured products was 16 in the case of prepreg mica tape and 25 in the case of dry mica tape. The results are shown in Table 1.

(2) Measurement of dielectric breakdown electric field strength The laminated cured product prepared by the above method is cut out to a size of 100 mm × 110 mm, and the dielectric breakdown voltage is measured using a dielectric strength test device (Tokyo Transformer Co., Ltd., 100 kV, 10 kVA type). It was measured. The number of laminated cured products was 3 for both the prepreg mica tape and the dry mica tape. The measurement conditions are based on JIS C2110, in electrical insulating oil (Fluorinert, FC-3283), frequency: commercial frequency 50Hz, boost speed: 2kV / sec, breaking current: 8mA, upper sphere electrode: φ20mm / made of brass, lower part. Electrode: φ25 mm / made of SUS, a total of 5 points were measured.

(3) Evaluation of chargeable deterioration life The laminated cured product prepared by the above method is cut out to a size of 100 mm × 110 mm, and the chargeable deterioration life is cut out using a Vt test device (Keinan Electric Co., Ltd., max: 50 kV). (Vt characteristic) was measured. The number of laminated cured products was 3 for both the prepreg mica tape and the dry mica tape. The measurement was performed in silicone oil (Shin-Etsu Chemical Co., Ltd., KF-96-50SC) as an electrical insulating oil, with a frequency of 50 Hz, an upper electrode: φ15 mm / copper, and a lower electrode: φ20 mm / copper, with one voltage. Wibble plots were prepared by measuring 7 points per level. The 5% probability value was calculated with the position parameter of this Weibull plot as 0, and the lifetime (h) at an electric field strength of 35 kV / mm was calculated. The results are shown in Table 1.

(4) Evaluation of wrapability The mica tape is spirally arranged so that half of the tape width overlaps from one end to the other end in the length direction of a metal plate having a length of 200 mm, a width of 30 mm, and a thickness of 9 mm as an insulator. Wrapped in a shape. At that time, the presence or absence of cracks, wrinkles, etc. in the mica tape was evaluated according to the following evaluation criteria. The results are shown in Table 1.
No cracks, wrinkles, etc ... A
Cracks, wrinkles, etc. can be seen in 1 to 4 places ... B
Cracks, wrinkles, etc. can be seen in 5 or more places ... C

(5) Measurement of mica tape thickness The mica tape thickness (μm) was determined by measuring the thickness of 10 points using a micrometer (Mitutoyo Co., Ltd., "MDC-SB") and calculating it as the arithmetic mean value. ..

(6) Measurement of mica layer thickness The mica layer thickness (μm) is determined by measuring the cross section of mica tape cut into a square of 30 mm × 30 mm with a stereomicroscope (“BX51” manufactured by Olympus Corporation) with respect to the width direction. Three points were observed with a micrometer, and the arithmetic mean value was calculated.

(7) Thickness ratio of mica layer The thickness ratio (%) of the mica layer was calculated from the average thickness of the mica tape and the average thickness of the mica layer by the following formula.
Mica layer thickness ratio = (average mica layer thickness / average mica tape thickness) x 100

(8) Calculation of mica content The mica content (volume%) in the mica layer is determined by cutting the mica tape into a square of 30 mm × 30 mm and heating it in an electric furnace at 600 ° C. for 1 hour with the solid content as the backing layer. After dividing into mica layers, the area, average thickness and mass of the mica layer were measured, and the mica content was calculated from the following formula. The density of mica was 2.95 g / cm ³ .
Mica content = {(mass of mica layer after heating / density of mica) / (area of mica layer x average thickness of mica layer)} x 100

(9) Measurement of particle size distribution of mica pieces A razor was inserted into the interface between the lining layer of the mica tape and the mica layer, and the mica layer was peeled off from the lining layer. 1 g of the peeled mica layer was dispersed in 100 g of methyl ethyl ketone, shaken for 10 minutes, and then centrifuged at 8000 rpm (rpm) for 5 minutes. To the remaining solid content after removing the supernatant, 100 g of methyl ethyl ketone was added, shaken for 10 minutes, and then centrifuged at 8000 rpm (rpm) for 5 minutes. Once again, 100 g of methyl ethyl ketone was added to the remaining solid content after removing the supernatant, and the mixture was shaken for 10 minutes and then centrifuged at 8000 rpm (rpm) for 5 minutes. After removing the supernatant, 100 g of methyl ethyl ketone was added to 1 g of the remaining solid content, dispersed with a mix rotor for 30 minutes, and shaken for another 10 minutes. Then, while shaking the container, a JIS standard sieve (JIS-Z-8801-1: 2006, ISO3310-1: 2000, manufactured by Tokyo Screen Co., Ltd., test sieve) in the order of opening 2.8 mm to 0.5 mm. ) Was sieved.

As a result of sieving, the ratio (mass%) of the residue remaining without passing through the sieve with a mesh size of 2.8 mm to the total amount of mica pieces before sieving is determined by "sieving using a JIS standard sieve". The proportion of mica pieces having a particle size of 2.8 mm or more at the time of
As a result of sieving, the total of the residue remaining without passing through the sieve with a mesh size of 2.8 mm and the residue remaining without passing through the sieve with a mesh size of 0.5 mm, before sieving. The ratio (mass%) of the mica pieces to the total amount was defined as "the ratio of mica pieces having a particle size of 0.5 mm or more when sieved using a JIS standard sieve".

As shown in Table 1, mica tapes of Examples mass per 1 m ² of the mica layer is 110g / ^{m 2} or more, in Comparative Examples 1 and 3 weight per 1 m ² of the mica layer is less than 110g / ^{m 2} Compared with mica tape, the evaluation of electrical insulation (particularly, the chargeable deterioration life time, which is an evaluation index of long-term electrical insulation) was higher.
On the other hand, mica tapes of Examples mass per 1 m ² of the mica layer is 160 g / ^{m 2} or less, compared to mica tapes of Comparative Examples 2 and 4 weight per 1 m ² of the mica layer is more than 160 g / ^{m 2} to be The wrapping property around the insulator was highly evaluated. From this, the insulating layer formed by winding the mica tape of Example around the insulated body has voids, cracks, etc. inside as compared with the insulating layer formed by winding the mica tape of Comparative Examples 2 and 4 around the insulated body. Is unlikely to occur, and it is considered that it is superior in electrical insulation.

1 Inorganic filler 2 Backing material 3 Resin component 4 Mica 5 Backing layer 6 Mica layer

Claims (14)

It has a coil conductor and an insulating layer arranged on the outer periphery of the coil conductor, the insulating layer contains mica tape, and the mica tape includes a mica layer containing mica and a lining containing a backing material and an inorganic filler. includes a layer, the mass per 1 m ² of the mica layer is Ri 130g ^{/ m 2} ~150g ^/ m 2 der, the proportion of mica nominal mesh opening does not pass through the JIS standard sieve is 2.8mm is, A coil for a rotary electric machine, which is less than 45% by mass of the total mica contained in the mica layer. The content of the mica mica layer is 45 vol% or less, rotary electric machine coil according to claim 1. The coil for a rotary electric machine according to claim 1 or 2, wherein the mica tape further contains a resin component. The mica tape according to any one of claims 1 to 3 , wherein the content of the inorganic filler is 20% by volume to 50% by volume of the total volume of the non-volatile content excluding the mica and the backing material. The coil for rotary electric machine described. The coil for a rotary electric machine according to any one of claims 1 to 4 , wherein the thickness ratio of the mica layer in the mica tape is 30% to 70%. The process of wrapping the mica tape around the outer circumference of the coil conductor and
The method for manufacturing a coil for a rotary electric machine according to any one of claims 1 to 5 , further comprising a step of forming an insulating layer from the mica tape wound around the outer periphery of the coil conductor. Mica layer containing mica has a backing layer containing a backing material and an inorganic filler, the weight of the mica layer is ^{130g / m 2 ~150g / m 2} , JIS nominal mesh opening is 2.8mm A mica tape in which the proportion of mica that does not pass through a standard sieve is less than 45% by mass of the total mica contained in the mica layer. The mica tape according to claim 7 , wherein the content of the mica in the mica layer is 30% by volume to 45% by volume. The mica tape according to claim 7 or 8 , wherein the content of the inorganic filler is 20% by volume to 50% by volume of the total volume of the non-volatile content excluding the mica and the backing material. The mica tape according to any one of claims 7 to 9, further comprising a resin component. The cured product of mica tape according to claim 10, which is obtained by curing the resin component. An insulator having an insulator and an insulating layer containing a cured product of mica tape according to claim 11, which is arranged on at least a part of the surface of the insulator. It has a coil conductor and an insulating layer arranged on the outer periphery of the coil conductor, the insulating layer contains mica tape, and the mica tape includes a mica layer containing mica and a lining containing a backing material and an inorganic filler. includes a layer, wherein the mass per 1 m ² of the mica layer is ^{110g / m 2 ~150g / m 2} , the proportion of mica nominal mesh opening does not pass through the JIS standard sieve is 0.5mm is, the der 40 mass% or more of the total mica contained in the mica layer is, nominal mesh opening does not pass through the JIS standard sieve is 2.8mm proportion of mica, less than 45% by weight of the total mica contained in the mica layer A coil for a rotating electric machine. Mica layer containing mica has a backing layer containing a backing material and an inorganic filler, the weight of the mica layer is ^{110g / m 2 ~150g / m 2} , JIS nominal mesh opening is 0.5mm the proportion of mica that does not pass through the standard sieve is state, and are 40 wt% or more of the total mica contained in the mica layer, the proportion of mica nominal mesh opening does not pass through the JIS standard sieve is 2.8mm is, the mica layer Mica tape that is less than 45% by mass of the total mica contained in.

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