Insulation sheet and motor

Abstract

To provide an insulation sheet having excellent thermal conductivity as well as excellent adhesiveness between an outer layer and an adhesive layer.SOLUTION: An insulation sheet includes: two outer layers 13 arranged to face each other; two adhesive layers 12 arranged to face each other between the two outer layers; and a substrate layer 11 arranged between the two adhesive layers. Each of the two adhesive layers 12 includes an inorganic filler.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an insulating sheet that is, for example, a component of a motor, and a motor including the insulating sheet. [Background technology]

[0002] Conventionally, an insulating sheet has been known which includes a base layer, two outer layers arranged to face one side and the other side of the base layer, and two adhesive layers respectively arranged between one and the other outer layer and the base layer.

[0003] Known examples of this type of insulating sheet include insulating sheets for motors, such as an insulating sheet with a five-layer structure in which a base layer is made of a polyester film and one outer layer and the other outer layer are bonded to the base layer by two adhesive layers made of an acrylic adhesive (for example, Patent Document 1).

[0004] In the insulating sheet described in Patent Document 1, the outer layer is adhered to an adhesive layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-262687 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the insulating sheet described in Patent Document 1 does not necessarily have good thermal conductivity. Therefore, there is a demand for an insulating sheet that has good thermal conductivity and good adhesion between the outer layer and the adhesive layer.

[0007] In view of the above problems and demands, an object of the present invention is to provide an insulating sheet having good thermal conductivity and good adhesion between the outer layer and the adhesive layer. Another object of the present invention is to provide a motor equipped with the above insulating sheet. [Means for solving the problem]

[0008] In order to solve the above problems, the insulating sheet according to the present invention comprises: The adhesive tape comprises two outer layers arranged to face each other, two adhesive layers arranged to face each other between the two outer layers, and a base material layer arranged between the two adhesive layers, and both of the two adhesive layers contain an inorganic filler.

[0009] A motor according to the present invention includes the insulating sheet described above. Effect of the Invention

[0010] The insulating sheet according to the present invention has good thermal conductivity and a relatively high adhesive strength between the outer layer and the adhesive layer. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view of an insulating sheet according to this embodiment cut in the thickness direction. [Diagram 2] FIG. 2 is a perspective view of the stator of the drive motor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of an insulating sheet according to the present invention will be described with reference to the drawings.

[0013] As shown in FIG. 1, the insulating sheet 10 of this embodiment comprises two outer layers 13 arranged opposite each other, two adhesive layers 12 arranged opposite each other between the two outer layers 13, and a base material layer 11 arranged between the two adhesive layers 12. In other words, the insulating sheet 10 of this embodiment comprises one base material layer 11, two adhesive layers 12 arranged to sandwich the base material layer 11 in the thickness direction, and two outer layers 13 arranged to sandwich the two adhesive layers 12 in the thickness direction. In this embodiment, the base material layer 11 is in direct contact with one of the adhesive layers 12, and the base material layer 11 is in direct contact with the other adhesive layer 12. In addition, on one side of the base material layer 11, the adhesive layer 12 is in direct contact with the outer layer 13, and also on the other side, the adhesive layer 12 is in direct contact with the outer layer 13. Each outer layer 13 may be the outermost layer of the insulating sheet 10 .

[0014] The thickness of the insulating sheet 10 is, for example, 50 μm or more and 500 μm or less. The thickness of the insulating sheet 10 may be 100 μm or more, or 150 μm or more. The thickness of the insulating sheet 10 may be 450 μm or less, or 400 μm or less. The thickness of the insulating sheet 10 is preferably 150 μm or more, and more preferably 200 μm or more, in order to improve the workability when inserting the sheet into a slot of a stator (described in detail later).

[0015] The thickness of the base layer 11 may be, for example, 25 μm or more and 200 μm or less. The thickness of the base layer 11 is preferably 100 μm or less.

[0016] The thickness of the adhesive layer 12 (per layer) may be, for example, 1 μm or more and 150 μm or less. The thickness of the adhesive layer 12 is preferably 5 μm or more and 100 μm or less, and more preferably 25 μm or more and 80 μm or less. Of the two adhesive layers 12, it is preferable that there is a small difference in thickness between one adhesive layer 12 and the other adhesive layer 12. For example, the thickness of one adhesive layer 12 may be 0.9 to 1.1 times the thickness of the other adhesive layer 12.

[0017] The thickness of the outer layer 13 (per layer) may be, for example, 10 μm or more and 200 μm or less. The thickness of the outer layer 13 is preferably 20 μm or more and 125 μm or less, and more preferably 25 μm or more and 75 μm or less. Of the two outer layers 13, it is preferable that there is a small difference in thickness between one outer layer 13 and the other outer layer 13. For example, the thickness of one outer layer 13 may be 0.9 times or more and 1.1 times or less the thickness of the other outer layer 13.

[0018] The thickness of each layer mentioned above refers to the average thickness. The thickness of each layer is determined by averaging the thicknesses of at least five randomly selected locations. The same applies below. The thickness of each layer can be measured, for example, by observing the side or cross section of the insulating sheet 10 with a digital microscope.

[0019] The ratio of the thickness of the base layer 11 to the total thickness of the insulating sheet 10 may be 0.10 or more, or may be 0.15 or more. This thickness ratio may be 0.50 or less, or may be 0.40 or less. A ratio of 0.15 or more has the advantage that the electrical insulation of the insulating sheet 10 is further improved.

[0020] The ratio of the total thickness of the adhesive layers 12 (thickness of two layers) to the total thickness of the insulating sheet 10 may be 0.10 or more, 0.15 or more, 0.20 or more, or 0.30 or more. Moreover, such a ratio may be 0.70 or less, or 0.60 or less. By having such a ratio of 0.30 or more, there is an advantage that the thermal conductivity of the insulating sheet 10 is further improved.

[0021] The ratio of the total thickness of the outer layers 13 (thickness of two layers) to the total thickness of the insulating sheet 10 is preferably 0.10 or more. This ratio may be 0.70 or less, or may be 0.50 or less. A ratio of 0.50 or less has the advantage that the thermal conductivity of the insulating sheet 10 is further improved.

[0022] It is preferable that the above-mentioned numerical range regarding the ratio of each thickness of the adhesive layer 12 to each thickness of the outer layer 13 is satisfied on at least one of the one surface side or the other surface side of the base layer 11. It is more preferable that the ratio of each thickness of the adhesive layer 12 to each thickness of the outer layer 13 is within the above-mentioned numerical range on both the one surface side and the other surface side of the base layer 11.

[0023] The base layer 11 in this embodiment is a resin film. Examples of the resin film include a heat-resistant resin film such as a polyimide resin film, a polyester resin film, etc. The resin film is preferably a polyester resin film.

[0024] Examples of the polyester resin film include films formed from a polymer of a dicarboxylic acid such as terephthalic acid or 2,6-naphthalenedicarboxylic acid and a diol such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, or 1,4-cyclohexanedimethanol. Specifically, examples of the polyester resin film include a polyethylene terephthalate resin (PET) film and a polyethylene naphthalate resin (PEN) film.

[0025] The base layer 11 is more preferably a polyethylene naphthalate resin film.

[0026] The base layer 11 may be a single layer as in this embodiment, or may be a laminate film in which a plurality of resin films are laminated.

[0027] As the base material layer 11, for example, a commercially available product such as the "Teonex" series (manufactured by Toyobo Co., Ltd.) can be used.

[0028] The two adhesive layers 12 constituting the insulating sheet 10 of this embodiment each contain an inorganic filler, and further contain a polymer component (adhesive component), a crosslinking agent, a tackifier, and the like.

[0029] The adhesive layer 12 may contain 20% by volume or more and 60% by volume or less of inorganic filler. The content of inorganic filler in the adhesive layer 12 is preferably 25% by volume or more. This has the advantage that the thermal conductivity of the adhesive layer 12 is further improved. The content of inorganic filler is preferably 50% by volume or less, and more preferably 45% by volume or less. This has the advantage that the adhesive layer 12 and the outer layer 13 can be more sufficiently bonded to each other. The above volume percentages are calculated from the mass and specific gravity of each material, specifically according to the following formula: Inorganic filler content [volume%] = 100×(A / A') / [(A / A')+(B / B')] A: mass of inorganic filler, A': specific gravity of inorganic filler, B: mass of polymer component, B': specific gravity of polymer component

[0030] Examples of the inorganic filler include magnesium carbonate filler and alumina filler. The inorganic filler preferably contains at least magnesium carbonate filler.

[0031] The shape of each particle of the inorganic filler is not particularly limited. The shape of each particle is, for example, spherical, needle-like, plate-like, or irregular (unspecified shape). The spherical shape includes a perfect sphere and an oval sphere.

[0032] The polymer component may, for example, be an acrylic polymer.

[0033] The acrylic polymer is preferably a polymer formed by polymerization of at least an alkyl (meth)acrylate ester. The acrylic polymer may be, for example, a polymer of an alkyl (meth)acrylate ester, or a copolymer of an alkyl (meth)acrylate ester and another polymerizable monomer. In this specification, the term "(meth)acrylic" includes both "acrylic" and "methacrylic".

[0034] Examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate [e.g., normal propyl (meth)acrylate, isopropyl (meth)acrylate, etc.], butyl (meth)acrylate [e.g., normal butyl (meth)acrylate, isobutyl (meth)acrylate, secondary butyl (meth)acrylate, tertiary butyl (meth)acrylate, etc.], 2-ethylhexyl (meth)acrylate, normal octyl (meth)acrylate, normal nonyl (meth)acrylate, and isononyl (meth)acrylate.

[0035] Examples of other polymerizable monomers include ethylene, styrene, vinyl chloride, acrylic acid, butadiene, and acrylonitrile.

[0036] Examples of the copolymer include ethylene-(meth)acrylic acid alkyl ester copolymer, ethylene-(meth)acrylic acid alkyl ester-acrylic acid copolymer, styrene-(meth)acrylic acid alkyl ester-acrylic acid copolymer, (meth)acrylic acid alkyl ester-vinyl chloride copolymer, (meth)acrylic acid alkyl ester-acrylic acid copolymer, (meth)acrylic acid alkyl ester-vinyl chloride copolymer, styrene-(meth)acrylic acid alkyl ester-butadiene copolymer, (meth)acrylic acid alkyl ester-acrylonitrile copolymer, and the like.

[0037] The acrylic polymer is preferably polybutyl acrylate (PAB), which is a polymer of at least butyl (meth)acrylate. Such polybutyl acrylate (PAB) may have a carboxy group or a hydroxy group in the molecule.

[0038] The above acrylic polymers may be used alone or in combination of two or more.

[0039] The crosslinking agent may, for example, be an isocyanate compound.

[0040] The isocyanate compound is preferably a polyfunctional isocyanate compound having a plurality of isocyanate groups in the molecule. Examples of the polyfunctional isocyanate compound include diphenylmethane diisocyanate, tolylene diisocyanate, and hexamethylene diisocyanate. The polyfunctional isocyanate compound may be an adduct formed by adding a tolylene diisocyanate trimer to trimethylolpropane.

[0041] Examples of the tackifier include petroleum-based resins such as aliphatic copolymers, aromatic copolymers, aliphatic-aromatic copolymers, and alicyclic copolymers, etc. Further examples include coumarone-indene resins, terpene resins, terpene phenol resins, rosin resins such as polymerized rosin, alkylphenol resins, xylene resins, and hydrogenated products thereof. The tackifier may be used alone or in combination of two or more kinds.

[0042] The adhesive layer 12 preferably contains a polymer compound which is a crosslinking reaction product between the above-mentioned polybutyl acrylate (PAB) as a polymer component and the above-mentioned isocyanate compound as a crosslinking agent. More preferably, the adhesive layer 12 contains a crosslinked reaction product of polybutyl acrylate (PAB) and an isocyanate compound, and an alkylphenol resin as a tackifier. This improves the adhesion between the adhesive layer 12 and the outer layer 13 (particularly aromatic polyamide paper). The amount of alkylphenol resin added is preferably 1 part by mass or more and 50 parts by mass or less, more preferably 30 parts by mass or less, per 100 parts by mass of polybutyl acrylate (PAB). Incidentally, polybutyl acrylate (PAB) may have a carboxy group in the molecule.

[0043] The weight of the adhesive layer 12 is, for example, 20 g / m 2 More than 240g / m 2 It may be the following.

[0044] The adhesive layer 12 may be formed of, for example, a commercially available polymer. The adhesive layer 12 may be formed of, for example, a polymer composition in which a plurality of types of polymers are crosslinked.

[0045] Both of the two outer layers 13 constituting the insulating sheet 10 of this embodiment are preferably aromatic polyamide paper. Since the outer layers 13 are aromatic polyamide paper, the insulating sheet 10 of this embodiment can have good heat resistance. In addition, after the insulating sheet 10 is placed in a slot of a motor stator, for example, good slip properties can be imparted when inserting a coil wire.

[0046] Examples of aromatic polyamide paper that can be used include fully aromatic polyamide paper made from at least one of short fibers made of fully aromatic polyamide and synthetic pulp made of fully aromatic polyamide, a sheet containing at least one of short fibers made of aromatic polyamide or synthetic pulp made of aromatic polyamide and mica powder (mica flakes), and sheets obtained by subjecting these papers or sheets to high-temperature and high-pressure calendar processing. As the aromatic polyamide paper, fully aromatic polyamide paper is preferred in that the insulating sheet 10 can have better heat resistance. Examples of the wholly aromatic polyamide constituting the above-mentioned short fibers or the above-mentioned synthetic pulp include a condensation polymer of m-phenylenediamine and isophthalic acid, and a condensation polymer of p-phenylenediamine and terephthalic acid.

[0047] The outer layer 13 may be laminated or surface-treated. The surface treatment may be performed using a coating agent containing a polyamide resin (e.g., a methoxymethylated polyamide resin in which an amide group is methoxymethylated). For example, a commercially available product (product name "Nomex" manufactured by DuPont, etc.) may be used as the outer layer 13.

[0048] The insulating sheet 10 of this embodiment is, for example, 1×10 13 The insulating sheet 10 has a volume resistivity of 1×10 14 It is preferable that the resistivity is Ω·cm or more.

[0049] The insulating sheet 10 of this embodiment has good thermal conductivity and a relatively high adhesive strength between the outer layer 13 and the adhesive layer 12. The adhesive strength can be further increased by including the acrylic polymer in the adhesive layer 12. The adhesive layer 12 can be provided with more sufficient thermal conductivity by including a magnesium carbonate filler as an inorganic filler.

[0050] Next, a method for producing the insulating sheet 10 of this embodiment will be described.

[0051] In the method for producing the insulating sheet 10 of this embodiment, for example, a mixture containing each component constituting the adhesive layer 12 and (if necessary) an organic solvent is prepared, the mixture is applied to both sides of the base layer 11, and the organic solvent contained in the applied mixture is volatilized (if necessary) to produce two adhesive layers 12. Furthermore, the insulating sheet 10 can be produced by bonding the outer layer 13 to each adhesive layer 12. As the coating device, for example, a roll coater can be used.

[0052] As the organic solvent, for example, ethyl acetate, methyl ethyl ketone (MEK), toluene, etc. can be used.

[0053] A general coating method such as die coating or reverse coating can be used when applying the mixture containing an organic solvent to the outer layer 13. The temperature during application is, for example, room temperature (15 to 25° C.).

[0054] The insulating sheet 10 manufactured as described above is used, for example, as a component of a motor. The insulating sheet 10 may be used, for example, as an insulating sheet for a drive motor of an automobile. Specifically, it can be used as slot insulating paper for a motor stator. The insulating sheet 10 can be used, for example, in a heated state.

[0055] Examples of automobiles include hybrid electric vehicles (HEVs) and electric vehicles (EVs). Examples of drive motors include HV motors, motor generators, alternators, 4WD motors, oil pump motors, EPS motors, compressor motors, in-wheel motors, etc.

[0056] Next, an embodiment of a motor according to the present invention will be described with reference to the drawings.

[0057] The motor of this embodiment includes the above-mentioned insulating sheet 10. The insulating sheet 10 is, for example, an insulating sheet for a motor.

[0058] For example, the motor is a drive motor mounted on a hybrid vehicle or an electric vehicle.

[0059] The drive motor of an automobile includes a rotor equipped with a permanent magnet and a stator 20 that generates a force for rotating the rotor. As shown in Fig. 2, the stator 20 has a coil 21 and a stator core 22. The stator 20 rotates the rotor by causing the coil 21 to generate a magnetic field.

[0060] In the above-mentioned driving motor, the coil 21 is formed, for example, by a plurality of segment conductors connected to each other. In the above-mentioned driving motor, a core such as the stator core 22 or the rotor core has a plurality of slot grooves, and each of the coils 21 is housed in each of the plurality of slot grooves. In addition, in the above-mentioned drive motor, a motor insulating sheet is used to ensure insulation between the coil 21 and the inner wall surface of the slot groove. The motor insulating sheet and the coil 21 are housed in the slot groove. More specifically, the motor insulating sheet is housed in the slot groove in a state where it is disposed around the coil 21. Coil 21 wound with a motor insulating sheet is fixed in the slot groove via insulating resin (for example, epoxy varnish) impregnated in the slot groove.

[0061] The insulating sheet and motor of this embodiment are as exemplified above, but the present invention is not limited to the insulating sheet or motor exemplified above. In other words, various configurations used in general insulating sheets or motors can be adopted as long as they do not impair the effects of the present invention.

[0062] The matters disclosed in this specification include the following. (1) The present invention provides a method for manufacturing a heat-resistant adhesive sheet comprising: two outer layers arranged to face each other; two adhesive layers arranged between the two outer layers to face each other; and a base layer arranged between the two adhesive layers; An insulating sheet, wherein both of the two adhesive layers contain an inorganic filler. (2) The insulating sheet according to (1) above, wherein each of the two adhesive layers contains the inorganic filler in an amount of 20% by volume or more and 50% by volume or less. (3) The insulating sheet according to the above (1) or (2), wherein the inorganic filler has a spherical particle shape. (4) The insulating sheet according to any one of (1) to (3) above, wherein the two outer layers are both aromatic polyamide papers. (5) The insulating sheet according to any one of (1) to (4) above, wherein each of the two adhesive layers contains an acrylic polymer. (6) The insulating sheet according to (5) above, wherein the acrylic polymer is an acrylic polymer formed by polymerization of at least an alkyl (meth)acrylate ester. (7) The insulating sheet according to (6) above, wherein the adhesive layer comprises a polymer compound which is a cross-linking reaction product between polybutyl acrylate (PAB), which is a polymer of butyl ester of (meth)acrylic acid as the alkyl ester of (meth)acrylic acid, and an isocyanate compound as a cross-linking agent, and an alkylphenol resin as a tackifier. (8) The insulating sheet according to any one of (1) to (7) above, wherein the base layer is a polyethylene naphthalate resin film. (9) A motor comprising the insulating sheet according to any one of (1) to (8) above. EXAMPLES

[0063] The present invention will now be described in more detail with reference to experimental examples, but the present invention is not limited to these.

[0064] The materials or raw materials for the outer layer, adhesive layer, and base layer used to manufacture the insulating sheet are shown below.

[0065] <Outer layer material> [Fully aromatic polyamide paper (PA paper)] Thickness: 40μm per layer Commercially available product <Raw materials for adhesive layer> [Inorganic filler] · Anhydrous magnesium carbonate filler (particle shape: irregular) Product name: Magthermo MS-S (manufactured by Konoshima Chemical Co., Ltd.) Alumina filler (particle shape: spherical) A mixture of 70:30 (mass ratio) of product names "AW-17-25" and "AX3-32" (both manufactured by Micron Corporation) [Polymer component] Polybutyl acrylate (PAB) (commercially available) 100 parts by weight [Crosslinking agent] Polyisocyanate compound (commercially available) 5 parts by weight [Tackifier] Alkylphenol resin (commercially available) 20 parts by weight

[0066] <Material for base layer> ·Polyethylene naphthalate resin film (PEN) Product name: Teonex Q51 (manufactured by Toyobo Co., Ltd.) Thickness: 50 μm

[0067] (Examples 1 to 9, Comparative Examples 1 to 3) The configurations (such as the thickness and material of each layer) of the insulating sheets of the examples and comparative examples are shown in Tables 1 and 2. Each of the insulating sheets of the examples and comparative examples has a five-layer laminate structure as shown in FIG. Each of Reference Examples 1 to 3 has a structure of one layer of resin film.

[0068] <Insulating sheet manufacturing> A mixture containing each of the above components constituting the adhesive layer and an organic solvent (methyl ethyl ketone (MEK)) was prepared. Each of these mixtures was applied to one side of the base layer using a bar coater so that the adhesive layer would have a predetermined thickness after drying. The organic solvent contained in the applied mixture was volatilized (dried) by drying treatment at 110°C for 3 minutes to prepare an adhesive layer on one side of the base layer. Furthermore, an outer layer was attached to the adhesive layer to prepare a three-layer laminate sheet. Then, an adhesive layer and an outer layer were prepared on the other side of the base layer in the same manner as above. In this manner, each insulating sheet with a five-layer structure was manufactured.

[0069] [Table 1]

[0070] [Table 2]

[0071] The insulating sheets produced in the respective Examples and Comparative Examples were evaluated for thermal conductivity and adhesive strength between the outer layer and the adhesive layer in the manner described below.

[0072] <Evaluation of thermal conductivity of insulating sheets> The thermal conductivity of each insulating sheet was measured at 62.5° C. by the protected heat flow method (steady state method) in accordance with ASTM E1530.

[0073] <Adhesion strength (peel strength) between the outer layer of the insulation sheet and the adhesive layer> For each insulating sheet, the peel force (peel strength) between the outer layer and the adhesive layer was measured as follows. Specifically, the peel force was measured using a tensile tester at a peel speed of 100 mm / min and a peel angle of 180° when the outer layer was pulled. The temperature during the measurement was 23° C.

[0074] The above test results are shown in Tables 1 and 2, respectively. As can be seen from Tables 1 and 2, the insulating sheets of the examples had higher thermal conductivity and higher adhesive strength between the outer layer and the adhesive layer than the insulating sheets of the comparative examples.

[0075] As can be seen from the results of Example 1, Examples 4 to 8, and Comparative Example 1, when the content of the anhydrous magnesium carbonate filler in the adhesive layer was less than 50% by volume, the aromatic polyamide paper (outer layer) underwent cohesive failure and exhibited better peel strength in the peel strength test. It can be said that the content of the anhydrous magnesium carbonate filler in the adhesive layer is particularly preferably 25% by volume or more and 45% by volume or less. As can be seen from the results of Examples 1 and 9, when the adhesive layer contains 50% by volume of inorganic filler, in the peel strength test, peeling occurred at the interface between the outer layer and the adhesive layer in Example 1, but cohesive failure occurred in the outer layer in Example 9. This is thought to be due to the particle shape of the inorganic filler. By having a spherical particle shape rather than an amorphous shape, the specific surface area of ​​the filler particles is reduced, and the polymer component (adhesive component) attached to the particle surface is reduced, which is thought to improve the adhesive strength between the outer layer and the pressure-sensitive adhesive layer. It can be said that the particle shape of the inorganic filler is preferably spherical. As can be seen from the results of Examples 2, 3, 6, and 8, and Comparative Examples 1 to 3, if the adhesive layer does not contain inorganic filler, the thermal conductivity does not depend on the thickness of the adhesive layer (Comparative Examples 1 to 3). On the other hand, in the adhesive layer containing inorganic filler, even if the content of inorganic filler is reduced, by increasing the thickness of the adhesive layer, the thermal conductivity is almost the same (Examples 2 and 6, Examples 3 and 8). By adjusting the content of inorganic filler and the thickness of the adhesive layer, respectively, the thermal conductivity can be maintained at a desired level.

[0076] In recent years, for example in the automotive industry, the electrification of automobiles has accelerated. Accordingly, the development of high-power, compact (lightweight) motors is progressing. However, as motors become more powerful, the amount of heat generated by the motor also increases. When the amount of heat generated increases, each component of the motor is required to have higher heat resistance. If the heat resistance limit is exceeded, the electrical resistance increases, which can lead to a decrease in the energy efficiency of the motor and a decrease in output. As the amount of heat generated from the coil wire in the stator that constitutes the motor will also increase in the future, there is a demand for the performance to efficiently transfer the generated heat to the core via the insulating sheet placed in the slot. In other words, it is desirable for the insulating sheet to have good thermal conductivity. [Industrial Applicability]

[0077] The insulating sheet of the present invention is preferably used, for example, as a component of a motor. The insulating sheet of the present invention is preferably used, for example, by being provided in a motor. [Explanation of symbols]

[0078] 11: Base material layer, 12: Adhesive layer, 13: Outer layer, 10: Insulating sheet.

Claims

1. The present invention provides a method for manufacturing a sheet-type adhesive tape comprising: two outer layers arranged to face each other; two adhesive layers arranged between the two outer layers to face each other; and a base layer arranged between the two adhesive layers; an insulating sheet, wherein the two adhesive layers each contain an inorganic filler.

2. The insulating sheet according to claim 1 , wherein each of the two adhesive layers contains the inorganic filler in an amount of 20% by volume or more and 50% by volume or less.

3. The insulating sheet according to claim 1 , wherein the inorganic filler has a spherical particle shape.

4. A motor comprising the insulating sheet according to claim 1 or 2.

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