JP2021188047A - Film for motor, motor, and method for manufacturing film for motor - Google Patents

Abstract

To provide a thinned film for motors that has improved slipperiness, resulting in easy insertion into a motor core or the like.SOLUTION: Provided is a film for motors that has a tensile elastic modulus of 2500 MPa or higher and a compressive strength of 50-1300 N, where at least one surface of the film has an arithmetic mean roughness (Ra) exceeding 0.1 μm.SELECTED DRAWING: None

Description

The present invention relates to a thinned motor film having excellent insertability by improving slipperiness, and more particularly to a film that can be suitably used as wedge paper or slot paper.

For motors that are the driving force for home appliances, industrial equipment, etc., conventionally, as an insulating film interposed between the core and the winding coil in the slot in the stator core, the slot paper and the opening of the slot groove are closed from the inside. Wedge paper is provided. These insulating films are usually incorporated by being inserted into the slot through an opening in the end face of the stator core.

In recent years, the performance of motors has been improved more and more, and in particular, small size and high efficiency motors are required. For this reason, a method of thinning the insulating film to increase the space factor of the winding coil may be adopted, but along with this, the insulating film such as wedge paper and slot paper is also required to have a thin wall, and in addition, excellent insertion is required. Sex is also becoming necessary.
Further, since heat tends to be trapped inside the motor due to the miniaturization, the refrigerant may be directly immersed in the stator core or the rotor core, and in addition to heat resistance, chemical resistance to the refrigerant and the like is also required.

As such an insulating film, aramid paper having a surface texture superior to that of a general resin film or the like, or a laminate obtained by laminating aramid paper with a resin film via an adhesive is widely used. Has been done.

However, compared to resin films and the like, aramid paper is more likely to form pinholes and the like due to thinning, and it is difficult to thin the aramid paper while suppressing a decrease in insulation reliability.
Moreover, since aramid paper is less stiff and more likely to buckle than a resin film having the same thickness, if it is made thinner, buckling may occur when it is inserted into a slot.
Further, in the laminated body of the aramid paper and the resin film, since only the products having the aramid paper of 50 μm or more are commercially available, the thickness becomes thick when a plurality of sheets are laminated, and the thickness is usually several hundred μm, and the size is reduced. It becomes difficult to use for a high-efficiency motor.
In addition, the fibers of the aramid paper may fluff when cut or inserted and remain inside the motor as foreign matter, which causes wear on the rotor and significantly reduces motor performance.

As a method for solving these problems, for example, Patent Document 1 discloses an insulating sheet having a predetermined surface roughness, and the insulating sheet can have slipperiness equivalent to that of aramid paper. There is a description. Further, if the arithmetic average roughness (Ra) of the insulating sheet is 0.05 μm or more and 0.1 μm or less and the arithmetic average roughness (Ra) is out of the above range, the slipperiness is poor and the insertability may be deteriorated. It is stated that there is.

Japanese Unexamined Patent Publication No. 2009-05567

As a result of further studies by the present inventors focusing on this arithmetic mean roughness (Ra), there is a relationship between the thickness and the degree of stiffness of the film and the roughness of the film surface. If the thickness is as described in, even if the slipperiness does not matter when it is actually inserted into the motor, if the thickness is further reduced, or if a film made of a weak resin is inserted into the motor. Then, it became clear that the slipperiness described in Patent Document 1 was insufficient.

The present invention has been made under such circumstances, and an object of the present invention is to provide a motor film having excellent insertability by improving slipperiness.

As a result of diligent studies, the present inventors have studied for motors that can solve the problems of the prior art by imparting specific surface texture to the surface of a film having a specific thickness and a specific compressive strength. We succeeded in obtaining a film and completed the present invention.

That is, the present invention provides the following [1] to [14].
[1] A resin film having a tensile elastic modulus of 2500 MPa or more and a compressive strength of 50 to 1300 N, and having an arithmetic mean roughness (Ra) of at least one side of more than 0.1 μm.
[2] A resin film having a tensile elastic modulus of 2500 MPa or more and a thickness of less than 300 μm, and having an arithmetic mean roughness (Ra) of at least one side of more than 0.1 μm.
[3] The film for a motor according to [1] or [2], wherein the arithmetic mean roughness (Ra) is 2 μm or less.
[4] The film for a motor according to any one of [1] to [3], wherein the arithmetic average height (Sa) of at least one side of the film is 0.1 to 3 μm.
[5] The film for a motor according to any one of [1] to [4], wherein the maximum height roughness (Rz) of at least one side of the film is 1 to 10 μm.
[6] The film for a motor according to any one of [1] to [5], wherein the maximum height (Sz) of at least one side of the film is 1.5 to 30 μm.
[7] The film for a motor according to any one of [1] to [6], which comprises at least one selected from the group consisting of polyetheretherketone and polyetherimide as the material of the film.
[8] The film for a motor according to any one of [1] to [7], wherein the dynamic friction coefficient between at least one side of the film and the stainless steel plate is 0.28 or less.
[9] The film for a motor according to any one of [1] to [8], wherein the static friction coefficient between at least one side of the film and the stainless steel plate is 0.42 or less.
[10] The film for a motor according to any one of [1] to [9], which has a folding resistance of 50 times or more at a thickness of 100 μm.
[11] The motor film according to any one of [1] to [10], which is a wedge paper.
[12] The motor film according to any one of [1] to [10], which is a slot paper.
[13] A motor using the motor film according to any one of [1] to [12].
[14] The method for producing a motor film according to any one of [1] to [12], which is produced by extrusion molding using a cast roll having an arithmetic average roughness (Ra) of 0.1 to 2 μm.

According to the present invention, it is possible to provide a film for a motor which is excellent in insertability while being a resin film having at least one of weakness and thinness.

It is a conceptual perspective view for demonstrating an insertability test.

Hereinafter, an example of the embodiment of the present invention will be described, but the present invention is not limited to the embodiment described below as long as the gist thereof is not exceeded.

The compressive strength in the present invention refers to a value measured by the method described in Examples described later with reference to JIS P8126: 2015.

The arithmetic mean roughness (Ra) and the maximum height roughness (Rz) in the present invention are measured according to JIS B0601: 2013 using a contact type surface roughness meter by the method described in Examples described later. Say the value.

The arithmetic mean height (Sa) and the maximum height (Sz) in the present invention refer to values measured by the method described in Examples described later using a white interference microscope.

The coefficient of dynamic friction and the coefficient of static friction in the present invention refer to JIS K7125: 1999 and refer to values measured by the method described in Examples described later.

In the present invention, "film" is not distinguished from "sheet", but is meant to include this.

In the present invention, when expressed as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, it means "X or more and Y or less", "preferably larger than X" and "preferably more than Y". It shall include the meaning of "small".
Further, in the present invention, when expressed as "X or more" (X is an arbitrary number), it includes the meaning of "preferably larger than X" and "Y or less" (Y is an arbitrary number) unless otherwise specified. ) Shall include the meaning of "preferably smaller than Y" unless otherwise specified.

In the present invention, the "main component" refers to the most abundant component in the object, preferably 50% by mass or more, more preferably 60% by mass or more, and further preferably 70% by mass in the object. It is particularly preferably 80% by mass or more, and most preferably 90% by mass or more.

The motor film according to the embodiment of the present invention (hereinafter, may be referred to as “the present film”) has a tensile elastic modulus of 2500 MPa or more, a compressive strength of 50 to 1300 N, and a thickness of at least 300 μm. A resin film comprising any of the above, wherein the resin film has at least one surface having a surface roughness having an arithmetic average roughness (Ra) of more than 0.1 μm. Since such a film is a film for a motor, it is usually an insulator.

That is, the present film according to one embodiment of the present invention has a tensile elastic modulus of 2500 MPa or more, a compressive strength of 50 to 1300 N, and an arithmetic mean roughness (Ra) of at least one side of more than 0.1 μm. ..
Further, the present film according to another embodiment of the present invention has a tensile elastic modulus of 2500 MPa or more, a thickness of less than 300 μm, and an arithmetic mean roughness (Ra) of at least one side of more than 0.1 μm. It is preferable to have the specific compressive strength.

It should be noted that the front and back surfaces of the resin film do not necessarily have to have the surface roughness, and the arithmetic average roughness (Ra) on one side is, for example, so that only the surface side in contact with the winding coil or the inner wall surface has the roughness. ) Is more than 0.1 μm, and it is also possible to use a resin film having a smooth surface on the other side.
Hereinafter, it will be described in detail.

[Material components of resin film]
The resin material of the resin film used for this film is not particularly limited, but for example, engineering plastics having heat resistance at 100 ° C. or higher and chemical resistance due to a refrigerant such as oil as the motor becomes smaller and more efficient. Is preferable, and it is more preferable that it is a super engineering plastic, but it is preferable that the film does not contain 5% by mass or more of fluororesin from the viewpoint of contaminating and corroding manufacturing equipment such as an extruder and reducing the amount of decomposed gas generated. It is more preferably not contained in an amount of 3% by mass or more, further preferably not contained in an amount of 1% by mass or more, and particularly preferably not contained substantially.
Specifically, polyether ether ketones, polyether ketone ketones, polyether ketones, polyether ketone ether ketone ketones, polyaryl ether ketone ether ketone ketones, polyaryl ether ketones, polyaryl ether ether ketones, polyether ether ketone ketones. , Polyaryl ether ether ketone Polyaryl ether ketone such as ketone, polyetherimide, polyetherimide sulfone, polyamide, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polysulfone, polyethersulfone, polyamideimide, polyimide , Polymethylpentene, liquid crystal polymer and the like, and these can be used alone or in combination of two or more, but it is preferable to use them alone or as a main component as one layer.
Of these, polyetheretherketone and polyetherimide are preferable.

Further, the present film may be a single layer or a multi-layer, but in the case of a multi-layer, for example, polyetheretherketone is used for one layer, and for example, polyetherimide is used for the other layer. A resin film having a two-layer structure formed by laminating different resins such as those used, or a resin film having a laminated structure of three or more layers can also be used as this film.

(Polyetheretherketone)
The polyetheretherketone may be a resin having at least two ether groups and a ketone group as structural units, but is excellent in thermal stability, melt moldability, rigidity, chemical resistance, impact resistance, and durability. Therefore, it preferably has a repeating unit represented by the following general formula (1).

(In the above general formula (1), Ar ^{1 to} Ar ³ independently represent an arylene group having 6 to 24 carbon atoms, and each may have a substituent).

In the general formula (1), ^{the arylene groups of Ar 1 to} Ar ³ may be different from each other, but are preferably the same. Examples of the arylene group of Ar ^{1 to} Ar ³ include a phenylene group and a biphenylene group. Of these, a phenylene group is preferable, and a p-phenylene group is more preferable.

Examples of the substituent that the arylene groups of Ar ^{1 to} Ar ³ may have include an alkyl group having 1 to 20 carbon atoms such as a methyl group and an ethyl group, and a carbon atom such as a methoxy group and an ethoxy group. Examples thereof include an alkoxy group having a number of 1 to 20. When Ar ^{1 to} Ar ³ have substituents, the number of the substituents is not particularly limited.

Among them, the polyetherketone having the repeating unit (a-1) represented by the following structural formula (2) is from the viewpoint of thermal stability, melt moldability, rigidity, chemical resistance, impact resistance, and durability. preferable. The repeating unit (a-1) has two ether groups and one ketone group.

The total number of repeating units of the polyetheretherketone represented by the formulas (1) and (2) (n: degree of polymerization of the formulas (1) and (2)) is preferably 10 or more. It is more preferably 20 or more. On the other hand, it is preferably 500 or less, more preferably 300 or less, and particularly preferably 100 or less. As long as the total number of repeating units (degree of polymerization) of the polyetheretherketone is within the range, this film tends to have excellent chemical resistance, heat resistance, and impact resistance, and the viscosity at the time of melting is not too high. It also tends to be excellent in melt moldability.

The number average molecular weight of the polyetheretherketone is preferably 10,000 or more, more preferably 12,000 or more, further preferably 14,000 or more, and particularly preferably 16,000 or more. On the other hand, it is preferably 35,000 or less, more preferably 32,000 or less, further preferably 30,000 or less, and particularly preferably 28,000 or less. As long as the number average molecular weight of the polyetheretherketone is within the range, this film tends to have excellent chemical resistance, heat resistance, and impact resistance, and also tends to have excellent melt moldability because the viscosity at the time of melting is not too high. Will be.

The number average molecular weight of the polyetheretherketone is such that the amorphous film of the polyetheretherketone is dissolved in pentafluorophenol by heating at, for example, 100 ° C. for 60 minutes, allowed to cool, and then chloroform at room temperature (23 ° C.) is added. The sample solution can be measured using gel permeation chromatography. As the eluent, pentafluorophenol / chloroform = 1/2 (mass ratio) is used, and the column temperature is 40 ° C., and the number average molecular weight can be obtained in terms of standard polystyrene.

The calorific value for crystal melting of the polyetheretherketone is preferably 20 J / g or more, more preferably 25 J / g or more, further preferably 30 J / g or more, and more preferably 35 J / g or more. Especially preferable. On the other hand, it is preferably 60 J / g or less, more preferably 55 J / g or less, and further preferably 50 J / g or less. As long as the amount of heat for crystal melting of the polyetheretherketone is within the range, the film tends to have excellent heat resistance and the heat energy given during melt molding can be small, so that the film tends to have excellent melt moldability.

The crystal melting temperature of the polyetheretherketone is preferably 300 ° C. or higher, more preferably 320 ° C. or higher, further preferably 330 ° C. or higher, particularly preferably 335 ° C. or higher, and 340 ° C. or higher. Most preferably, it is above ° C. On the other hand, the upper limit is preferably 400 ° C. or lower, more preferably 380 ° C. or lower, and even more preferably 360 ° C. or lower. As long as the crystal melting temperature of the polyetheretherketone is within the range, this film tends to have excellent heat resistance and also has excellent melt moldability because the viscosity at the time of melting is not too high.

The glass transition temperature of the polyetheretherketone is preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and even more preferably 140 ° C. or higher. On the other hand, it is preferably 200 ° C. or lower, more preferably 190 ° C. or lower, and even more preferably 180 ° C. or lower. Within the range where the glass transition temperature of the polyetheretherketone is applied, this film tends to have excellent heat resistance and also tends to have excellent melt moldability because the viscosity at the time of melting is not too high.

The amount of heat of crystal melting in the present invention is determined by using a differential scanning calorimeter (for example, Pyris1 DSC manufactured by PerkinElmer) in a temperature range of 25 to 400 ° C. and a heating rate of 10 ° C./min according to JIS K7122: 2012. It can be obtained from the area of the melting peak of the detected DSC curve by raising the temperature.
The crystal melting temperature in the present invention is set in a temperature range of 25 to 400 ° C. and a heating rate of 10 ° C./min using a differential scanning calorimeter (for example, Pyris1 DSC manufactured by PerkinElmer) according to JIS K7121: 2012. It can be obtained from the peak top temperature of the melting peak of the detected DSC curve by raising the temperature.
The glass transition temperature in the present invention is raised in a temperature range of 25 to 400 ° C. and a heating rate of 10 ° C./min using a differential scanning calorimeter (for example, Pyris1 DSC manufactured by PerkinElmer) according to JIS K7121: 2012. It can be obtained from the detected DSC curve.

The polyetheretherketone can be produced by a known production method, and a commercially available product can also be used. Examples of commercially available products include, for example, the "VICTREX PEEK" series manufactured by Victrex, the "KetaSpire" series manufactured by Solvay, and the "VESTAKEP" series manufactured by Daicel Evonik.

(Polyetherimide)
The polyetherimide is not particularly limited, but preferably has a repeating unit represented by the following general formula (3).

(In the general formula (3), Y ^{1 to Y 6} independently represent a hydrogen atom, an alkyl group, or an alkoxy group, and Ar ^{7 to} Ar ⁹ independently have a substituent. It represents a good arylene group with 6 to 24 carbon atoms, where X ¹ is a direct bond or -O-, -SO _2- , -S-, -C (= O)-, or a divalent aliphatic hydrocarbon. Represents one of the hydrogen groups.)

In the general formula (3), ^{the arylene groups of Ar 7 to} Ar ⁹ may be different from each other, but are preferably the same. Specific examples of the arylene group of Ar ^{7 to} Ar ⁹ include a phenylene group and a biphenylene group, and among these, a phenylene group is preferable.
Examples of the substituent that the arylene group of Ar ^{7 to} Ar ⁹ may have include an alkyl group having 1 to 20 carbon atoms such as a methyl group and an ethyl group, and a carbon atom number 1 such as a methoxy group and an ethoxy group. Examples thereof include ~ 20 alkoxy groups. When Ar ^{7 to} Ar ⁹ have substituents, the number of the substituents is not particularly limited.

Among them, from the viewpoint of mechanical properties, thermal stability, and melt moldability, the repeating unit represented by the general formula (3) contained in the polyetherimide is a repeating unit represented by the following structural formula (4). It is more preferable to have b-1) or a repeating unit (b-2) represented by the following structural formula (5).

In general, polyetherimides are classified into structures according to the difference in bonding mode, that is, the difference between meta-bonding and para-bonding, and each has different mechanical properties and heat resistance.

The total number of repeating units of the formulas (3) to (5) (n: degree of polymerization of the formulas (3) to (5)) of the polyetherimide is preferably 10 or more, preferably 20 or more. Is more preferable. On the other hand, the upper limit is preferably 1000 or less, more preferably 700 or less, and further preferably 500 or less. As long as the total number (degree of polymerization) of the repeating units of the above formulas (3) to (5) of the polyetherimide is within the range, this film tends to have excellent heat resistance and the viscosity at the time of melting is not too high. It also tends to be excellent in melt moldability.

The number average molecular weight of polyetherimide measured by gel permeation chromatography is preferably 15,000 or more, more preferably 20,000 or more, further preferably 22,000 or more, and particularly preferably 24,000 or more. preferable. On the other hand, it is preferably 50,000 or less, more preferably 45,000 or less, further preferably 40,000 or less, and particularly preferably 38,000 or less. As long as the number average molecular weight of the polyetherimide is within the range, this film tends to have excellent chemical resistance, heat resistance, and impact resistance, and also tends to have excellent melt moldability because the viscosity at the time of melting is not too high. Become.

The glass transition temperature of the polyetherimide is preferably 140 ° C. or higher, more preferably 160 ° C. or higher, further preferably 180 ° C. or higher, and particularly preferably 200 ° C. or higher. On the other hand, it is preferably 300 ° C. or lower, more preferably 280 ° C. or lower, and even more preferably 260 ° C. or lower. As long as the glass transition temperature of the polyetherimide is applied, this film tends to have excellent heat resistance, and since the viscosity at the time of melting is not too high, the film tends to have excellent melt formability.

Polyetherimide can be produced by a known production method. Further, a commercially available product can also be used. Examples of commercially available products include the "Ultem" series manufactured by SABIC.

The polyetheretherketone and the polyetherimide are preferably the main components of this film. That is, it is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, particularly preferably 80% by mass or more, and most preferably 90% by mass or more of the entire film. It is mass% or more.

In addition, this film contains various types of heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antibacterial / antifungal agents, antistatic agents, lubricants, pigments, dyes, etc., as long as the effects of the present invention are not impaired. Additives may be included. However, from the viewpoint of the number of folding times, inorganic particles such as silica are preferably not contained in the film in an amount of 1% by mass or more, more preferably 0.5% by mass or more, and not contained in an amount of 0.1% by mass or more. It is more preferable, and it is preferable that it is not substantially contained.

[Production method]
This film can be manufactured by general molding methods such as extrusion molding, injection molding, blow molding, vacuum molding, pressure molding, press molding and the like. In each molding method, the apparatus and processing conditions are not particularly limited, but from the viewpoint of productivity and thickness control, extrusion molding, particularly the T-die method is preferable.

The method for producing this film is not particularly limited, but for example, the constituent material of the film can be obtained as a non-stretched or stretched film, and from the viewpoint of secondary processability, it is preferably obtained as a non-stretched film. The non-stretched film is a film that is not positively stretched for the purpose of controlling the orientation of the sheet, and includes a film that is oriented when it is taken up by a cast roll by the T-die method.

In the case of a non-stretched film, for example, it can be produced by melt-kneading each constituent material, extrusion molding, and cooling. A known kneader such as a single-screw or twin-screw extruder can be used for melt-kneading. Molding can be performed, for example, by extrusion molding using a mold such as a T-die.

When the laminated film is produced, the laminating method is not particularly limited, and for example, a coextrusion method in which the resin composition of each layer is coextruded and laminated, an extrusion laminating method in which each layer is formed into a film and laminated, and each layer is formed. It may be formed into a film and may be molded by any of the thermal crimping methods in which these are thermally crimped, but from the viewpoint of productivity, it is preferably molded by the coextrusion method. The coextrusion method includes a multi-manifold method in which the resin compositions of each layer are merged by a mouthpiece, a feed block method in which the resin compositions of each layer are merged by a feed block, and the like, and any of them may be used.

It is important that this film has at least one surface having a surface roughness with an arithmetic mean roughness (Ra) of more than 0.1 μm. The method for adjusting the arithmetic mean roughness (Ra) is not particularly limited, but for example, transfer treatment such as emboss roll transfer, emboss belt transfer, emboss film transfer, sandblast treatment, shot blast treatment, etching treatment, and engraving treatment. , Various methods such as surface crystallization can be used. Among them, a method of roughening by casting a film-shaped molten resin on a cast roll is preferable because it is easy to continuously and uniformly form surface irregularities while extruding the molten resin into a film. In this case, the surface roughness of the resin film can be adjusted by adjusting the arithmetic average roughness (Ra) of the cast roll. The arithmetic mean roughness (Ra) of the cast roll is preferably 0.1 μm or more, more preferably more than 0.1 μm, further preferably 0.5 μm or more, and more preferably 0.7 μm or more. Is even more preferable. Further, it is preferably 2 μm or less, more preferably 1.7 μm or less, and further preferably 1.5 μm or less.

[Film for motor]
This film has at least one surface having a surface roughness with an arithmetic mean roughness (Ra) of more than 0.1 μm, and the front and back surfaces of the film do not necessarily have to have the surface roughness, but the motor. It is preferable to provide both sides from the viewpoint of insertability into a core or the like.

This film has an arithmetic average roughness (Ra) of more than 0.1 μm measured using a contact type surface roughness meter in accordance with JIS B0601: 2013. It is preferably 0.15 μm or more, more preferably 0.2 μm or more, further preferably 0.3 μm or more, and particularly preferably 0.5 μm or more. When the arithmetic mean roughness (Ra) of this film is equal to or higher than the lower limit, the surface of this film is not too smooth and has an appropriate roughness, so that the slipperiness is good. For example, it is inserted into a motor core. There is an advantage that the property is improved and the problem of buckling or breakage at the time of insertion is less likely to occur.
On the other hand, the arithmetic mean roughness (Ra) is preferably 2 μm or less, more preferably 1.7 μm or less, further preferably 1.5 μm or less, and particularly preferably 1.2 μm or less. preferable. By setting the arithmetic average roughness (Ra) of this film to the above upper limit or less, slipping, slippage, twisting, wrinkling, etc. may occur on the transport roll during film transport during manufacturing, or slip between films. There is an advantage that problems such as winding misalignment of the roll due to excessiveness are less likely to occur.

This film has at least one surface having a surface roughness with a maximum height roughness (Rz) of 1 to 10 μm measured using a contact type surface roughness meter in accordance with JIS B0601: 2013. It is preferably 1.5 μm or more, more preferably 2 μm or more, particularly preferably 3 μm or more, further preferably 9 μm or less, still more preferably 8 μm or less. , 7 μm or less is particularly preferable. Within the range where the maximum height roughness (Rz) is applied, the insertability into a motor core or the like is excellent, and the buckling or breakage at the time of insertion tends to be easily prevented.

This film preferably has a surface having a surface roughness of 0.1 to 3 μm in arithmetic mean height (Sa) measured using a white interference microscope, preferably 0.15 μm or more. It is more preferably 0.25 μm or more, particularly preferably 0.3 μm or more, further preferably 2.5 μm or less, still more preferably 2 μm or less. It is particularly preferably 5 μm or less. Within the range where the arithmetic mean height (Sa) is applied, the insertability into a motor core or the like is excellent, and the buckling or breakage at the time of insertion tends to be easily prevented.

This film preferably has at least one surface having a surface roughness with a maximum height (Sz) of 1.5 to 30 μm measured using a white interference microscope, and is preferably 2 μm or more. It is more preferably 3 μm or more, more preferably 28 μm or less, further preferably 25 μm or less, and particularly preferably 20 μm or less. Within the range where the maximum height (Sz) is applied, the insertability into a motor core or the like is excellent, and the buckling or breakage at the time of insertion tends to be easily prevented.

The compressive strength of this film measured with reference to JIS P8126: 2015 is preferably 50 to 1300 N, more preferably 60 N or more, further preferably 70 N or more, and even more preferably 80 N or more. On the other hand, it is more preferably 1200 N or less, further preferably 1100 N or less, and particularly preferably 1050 N or less. Within the range where the compressive strength is applied, buckling and breakage at the time of insertion into the motor core or the like can be prevented, and by extension, the insertability into the motor core or the like tends to be excellent.

This film preferably has a thickness of 100 μm and a folding resistance in the extrusion direction (MD) of the film, measured in accordance with JIS P8115: 2001, preferably 50 times or more, more preferably 60 times or more, and 100 times. It is more preferably more than 150 times, and particularly preferably 150 times or more. As long as the number of times of folding resistance is long, it tends to be a tough film that is hard to tear even if it is repeatedly deformed.

This film preferably has a tensile elastic modulus of 2500 MPa or more measured under the conditions of a tensile speed of 5 mm / min and a tensile modulus of 23 ° C. in the extrusion direction (MD) of the film. It is more preferably 2600 MPa or more, further preferably 2800 MPa or more, and particularly preferably 3000 MPa or more. When the tensile elastic modulus of this film is at least the above lower limit value, the film has excellent rigidity and tends to be easy to handle even if the thickness is thin. The tensile elastic modulus is preferably 10,000 MPa or less, more preferably 7500 MPa or less, and even more preferably 5000 MPa or less. It is preferable to set the tensile elastic modulus to be equal to or lower than the upper limit value because it imparts appropriate flexibility to the film and makes it easier to insert it into a motor core or the like.

In this film, the coefficient of dynamic friction between at least one side of the film and the stainless steel plate, measured in accordance with JIS K7125: 1999, is preferably 0.28 or less, more preferably 0.26 or less, and 0. It is more preferably 25 or less. On the other hand, it is preferably 0.01 or more, and more preferably 0.05 or more.
As long as the coefficient of kinetic friction with the stainless steel plate of this film is within the range, it is excellent in insertability into a motor core or the like, and by extension, it tends to be easy to prevent buckling or breakage during insertion.

In this film, the coefficient of static friction between at least one side of the film and the stainless steel plate, measured in accordance with JIS K7125: 1999, is preferably 0.42 or less, more preferably 0.40 or less, and 0. It is more preferably .38 or less, and particularly preferably 0.36 or less. On the other hand, it is preferably 0.01 or more, and more preferably 0.05 or more.
As long as the coefficient of static friction with the stainless steel plate of this film is within the range, it is excellent in insertability into a motor core or the like, and by extension, it tends to be easy to prevent buckling or breakage during insertion.

The volume porosity of this film is preferably less than 20%, more preferably 10% or less, further preferably 5% or less, particularly preferably 1% or less, and pores. It is particularly preferable that the film does not substantially contain. By setting the volume porosity within the range, it is preferable that the decrease in heat conduction is suppressed and the cooling efficiency tends to be improved more easily. The volume porosity can be calculated by using the specific gravity of this film and the raw material resin used for this film.

The thickness of this film is preferably 30 μm or more, more preferably 50 μm or more, further preferably 80 μm or more, and particularly preferably 100 μm or more. On the other hand, it is preferably 400 μm or less, more preferably 300 μm or less, further preferably less than 300 μm, further preferably 250 μm or less, particularly preferably 220 μm or less, and particularly preferably 200 μm or less. Most preferably. When the thickness is not less than the lower limit, the film has sufficient insulating properties and rigidity, and tends to prevent current leakage during use and buckling during insertion. Further, when the thickness is not more than the upper limit value, the density of the coil inserted into the motor core or the like can be increased, and the motor efficiency tends to be maintained high.

This film is a resin film having a compressive strength of 50 to 1300 N, at least one having a thickness of less than 300 μm, and a tensile elastic modulus of 2500 MPa or more, and has an arithmetic mean roughness (Ra) of at least one side. Since the length is more than 0.1 μm, even a resin film having a weak elasticity or a small thickness can be easily inserted into the motor core.

This film may be either a single layer or a multi-layer, but in the case of a multi-layer using at least one of a polyether ether ketone layer and a polyether imide layer, the total of the polyether ether ketone layer and the polyether imide layer. The thickness is preferably 70% or more, more preferably 80% or more, further preferably 90% or more, and most preferably 100% of the entire film.

Further, in the case of a multilayer layer using a polyether ether ketone layer and a polyetherimide layer, the thickness ratio of the polyether ether ketone layer / polyetherimide layer is preferably 1/9 to 5/5, preferably 1/9. It is more preferably ~ 4/6, and even more preferably 2/8 to 3/7.

When this film is a multi-layer using a polyether ether ketone layer and a polyetherimide layer, it may contain a layer other than the polyether ether ketone layer and the polyetherimide layer as long as the effect of the present invention is not impaired. good.

[Usage / Usage]
Since this film has excellent insertability into motor cores by improving slipperiness, home appliances, audio equipment, IT equipment, communication equipment, OA equipment, medical equipment, healthcare equipment, commercial equipment, industrial equipment, etc. It can be suitably used for motors for transportation equipment such as automobiles, railroads, and ships. In particular, it can be suitably used as wedge paper or slot paper.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

1. 1. Production of Films In Examples and Comparative Examples, the following raw materials were used to produce films having the composition shown in Table 1 below.

[Polyetheretherketone]
(A) -1: VESTAKEE P 3300G (manufactured by Daisel Ebonic, repeating unit of (a-1), degree of polymerization n = 59, number average molecular weight = 17000, crystal melting temperature = 343 ° C., crystal melting heat = 41 J / g , Glass transition temperature = 143 ° C)

[Polyetherimide]
(B) -1: Ultem 1000-1000 (manufactured by SABIC, repeating unit of (b-1), degree of polymerization n = 57, number average molecular weight = 34000, glass transition temperature = 217 ° C.)
(B) -2: Ultem CRS5001-1000 (manufactured by SABIC, repeating unit of (b-2), degree of polymerization n = 47, number average molecular weight = 27700, glass transition temperature = 227 ° C.)

<Example 1>
(A) -1 was used as a raw material for the polyetheretherketone layer (PEEK layer), and (B) -1 was used as a raw material for the polyetherimide layer (PEI layer). These were separately melted using two Φ40 mm single-screw extruders (PEEK side 380 ° C., PEI side 380 ° C.). The PEEK layer is divided into halves by a feed block and laminated in the feed block in the order of PEEK layer / PEI layer / PEEK layer to form a two-kind three-layer laminated film with a lamination ratio of 1 /. Extruded from a T-die (base temperature 380 ° C.) so as to be 8/1 (thickness ratio of PEEK layer to the entire film = 20%) to obtain a laminated film having a thickness of 100 μm. Here, one surface of the film was roughened by casting on a cast roll having an arithmetic mean roughness (Ra) of 1.05 μm.

<Example 2>
Polyetherimide (B) -2 was used as a raw material. The raw materials were melt-kneaded using a Φ40 mm single-screw extruder, extruded continuously from the T-die, and cast on a cast roll having an arithmetic mean roughness (Ra) of 1.05 μm to obtain a single-layer film having a thickness of 100 μm. The extruder temperature and the base temperature at this time were both set to 380 ° C.

<Example 3>
A single-layer film having a thickness of 200 μm was obtained by the same method as in Example 2 except that the polyether ether ketone (A) -1 was used as a raw material and the extruder temperature and the base temperature were both set to 380 ° C. ..

<Comparative Example 1>
A laminated film having a thickness of 100 μm was obtained by the same method as in Example 1 except that the arithmetic average roughness (Ra) of the cast roll was 0.07 μm.

<Reference example 1>
Polyetherimide (B) -2 was used as a raw material for the polyetherimide layer (PEI layer), and a laminated film was obtained in the same manner as in Example 1 except that the thickness of the laminated film was set to 300 μm.

<Reference example 2>
Except for the fact that polyetherimide (B) -2 was used as the raw material for the polyetherimide layer (PEI layer), the arithmetic mean roughness (Ra) of the cast roll was 0.07 μm, and the thickness of the laminated film was 300 μm. A laminated film was obtained in the same manner as in Example 1.

Arithmetic mean roughness (Ra), maximum height roughness (Rz), arithmetic mean height (Sa), and maximum height described below for the films of Examples, Comparative Examples, and Reference Examples obtained by the above method. The roughness (Sz), compressive strength, number of foldings, tensile elastic modulus, dynamic friction coefficient, static friction coefficient, and insertability were evaluated. The direction in which the film-shaped molded product is extruded from the T-die is defined as the “vertical” of the film, and the direction orthogonal to this in the film surface is defined as the “horizontal” of the film.
The obtained evaluation results are shown in Table 1.

2. 2. Film evaluation (1) Arithmetic mean roughness (Ra), maximum height roughness (Rz)
For the surface on the roughened side of the film, using a contact type surface roughness meter Surf Coder ET4000A (manufactured by Kosaka Research Institute), the tip radius of the stylus is 0.5 mm, the measurement length is 8.0 mm, and the reference length. Measurements were performed in the vertical direction of the film under the conditions of 8.0 mm, a cutoff value of 0.8 mm, and a measurement speed of 0.2 mm / sec, and the arithmetic average roughness (Ra) and the maximum height roughness (Rz) were calculated.

(2) Arithmetic mean height (Sa), maximum height (Sz)
For the surface on the roughened side of the film, using a white interference microscope Function GT-X (manufactured by BRUKER), the conditions are that the eyepiece magnification is 1.0 times, the objective lens magnification is 20 times, and the measurement area is 235 μm in length × 313 μm in width. After performing the smoothing process with the Gaussian function, the arithmetic average height (Sa) and the maximum height (Sz) were calculated.

(3) Compressive strength First, in a test piece support consisting of a block (outer frame) having a cylindrical recess and a removable disk (inner frame), a circular groove is formed by attaching the disk to the block. Is formed, and the test piece is supported by sandwiching the test piece in this groove. The recess of the block has an inner diameter of 49.8 mm and a depth of 6.35 mm, and the outer diameter of the disc is 49.6 mm when the film thickness is 100 μm, 49.5 mm when the film thickness is 200 μm, and 49.3 mm when the film thickness is 300 μm. The thickness of the disc was 6.35 mm.
The test piece is made into a strip shape by punching from the film using a punching blade having a width of 12.7 mm (longitudinal direction of the film) and a length of 157 mm (horizontal direction of the film). If the ends overlapped when placed in the groove of the one-sided support, the extra length was cut off.
After placing the test piece on the test piece support, the tester is operated until the test piece is crushed using the precision universal testing machine Autograph AG-X (manufactured by Shimadzu Corporation), and the maximum compression force when the test piece is crushed. Was measured and used as the compression strength.

(4) Folding resistance For each film having a thickness of 100 μm, the folding resistance was measured in the vertical direction of the film using a MIT bending fatigue tester (manufactured by Toyo Seiki Co., Ltd.) in accordance with JIS P8115: 2001. For Examples 3 and Reference Examples 1 and 2, in the case of laminating, a film having a thickness of 100 μm for measuring the number of foldings was separately prepared in the same manner with the same laminating ratio, and measurement was performed.

(5) Tension elastic modulus For each film, a strip test piece with a length of 400 mm and a width of 5 mm was prepared, and a tensile compression tester type 205 (manufactured by Intesco) was used to create an atmospheric temperature of 23 ° C., a chuck distance of 300 mm, and tensile strength. The tensile elastic modulus (MPa) was measured in the longitudinal direction of the film under the condition of a speed of 5 mm / min.

(6) Coefficient of dynamic friction with stainless steel plate, coefficient of static friction A test piece was cut out from the roughened side surface of the film. With reference to JIS K7125: 1999, the surface of the roughened side of the test piece and the stainless steel plate were kept in contact for 15 seconds before the start of the test, and then the measurement was performed in the vertical direction under the following conditions to make stainless steel. The coefficient of dynamic friction and the coefficient of static friction with the plate were evaluated.
・ Equipment: Plastic film slip tester (manufactured by Intesco)
-Sliding piece: Total mass 200 g (square with a contact area of 63 mm on each side)
・ Contact area: 40 cm ²
・ Test speed: 100 mm / min ・ Temperature: 23 ° C ± 2 ° C
・ Relative humidity: 50% ± 10%

(7) Insertability A test piece having a width of 235 mm (horizontal direction of the film) and a length of 210 mm (longitudinal direction of the film) is cut out from the film, and the end of the film is taped to form an inner diameter of 75 mm and a length as shown in FIG. A 210 mm cylindrical test piece 1 was produced. The test piece 1 was manufactured so that the inside of the cylinder had a roughened surface (even when used in an actual product, the copper wire side of the motor usually has a roughened surface).
A plastic lid 2 having a length of 66 mm, an inner diameter of 75 mm, and a head diameter of 99 mm was attached to one end of the test piece 1 and placed on an iron plate 3. Subsequently, at the other end of the test piece 1, an iron weight 4 having a bottom surface of 30 mm × 75 mm and a mass of 1057 g is placed in the cylindrical test piece 1, and the weight 4 does not move in the length direction of the test piece 1. It was fixed with the fixture 5 as described above. When the test piece 1 is pushed in the length direction (arrow direction) from the end to which the lid material 2 is attached, the test piece 1 moves 50 mm or more as insertability ○, and the test piece 1 buckles or breaks before moving 50 mm or more. Insertability ×.

The films obtained in Examples 1 to 3 had an arithmetic mean roughness (Ra) of more than 0.1 μm and were excellent in insertability. This effect is due to the film of the present invention in which a surface having a large arithmetic mean roughness (Ra) is arranged on at least one side. A motor obtained by using such a film having excellent insertability is excellent in motor performance.
On the other hand, in Comparative Example 1, the arithmetic mean roughness (Ra) was 0.1 μm or less, the coefficient of dynamic friction and the coefficient of static friction were large, and the insertability was also inferior.
Reference Examples 1 and 2 are both films having high compressive strength and a large thickness. It can be seen that in such a film, even if the arithmetic mean roughness (Ra) exceeds 0.1 μm (Reference Example 1) or falls below (Reference Example 2), the problem of insertability is unlikely to occur.

Since the motor film of the present invention has excellent insertability into a motor core or the like, home appliances, audio equipment, IT equipment, communication equipment, OA equipment, medical equipment, healthcare equipment, commercial equipment, industrial equipment, automobiles and railways -Widely used for motors for transportation equipment such as ships.

1 Test piece 2 Cover material 3 Iron plate 4 Weight 5 Fixture

Claims (14)

A resin film having a tensile elastic modulus of 2500 MPa or more and a compressive strength of 50 to 1300 N, and having an arithmetic mean roughness (Ra) of at least one side of more than 0.1 μm. A resin film having a tensile elastic modulus of 2500 MPa or more and a thickness of less than 300 μm, and having an arithmetic mean roughness (Ra) of at least one side of more than 0.1 μm. The film for a motor according to claim 1 or 2, wherein the arithmetic mean roughness (Ra) is 2 μm or less. The film for a motor according to any one of claims 1 to 3, wherein the arithmetic mean height (Sa) of at least one side of the film is 0.1 to 3 μm. The film for a motor according to any one of claims 1 to 4, wherein the maximum height roughness (Rz) of at least one side of the film is 1 to 10 μm. The motor film according to any one of claims 1 to 5, wherein the maximum height (Sz) of at least one side of the film is 1.5 to 30 μm. The film for a motor according to any one of claims 1 to 6, which comprises at least one selected from the group consisting of polyetheretherketone and polyetherimide as the material of the film. The motor film according to any one of claims 1 to 7, wherein the dynamic friction coefficient between at least one side of the film and the stainless steel plate is 0.28 or less. The film for a motor according to any one of claims 1 to 8, wherein the static friction coefficient between at least one side of the film and the stainless steel plate is 0.42 or less. The motor film according to any one of claims 1 to 9, wherein the film has a folding resistance of 50 times or more at a thickness of 100 μm. The motor film according to any one of claims 1 to 10, which is a wedge paper. The film for a motor according to any one of claims 1 to 10, which is a slot paper. A motor using the motor film according to any one of claims 1 to 12. The method for producing a film for a motor according to any one of claims 1 to 12, which is produced by extrusion molding using a cast roll having an arithmetic mean roughness (Ra) of 0.1 to 2 μm.

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