WO2012153636A1 - Polyimide resin varnish, insulated electric wire using same, electric coil, and motor - Google Patents

Polyimide resin varnish, insulated electric wire using same, electric coil, and motor Download PDF

Info

Publication number
WO2012153636A1
WO2012153636A1 PCT/JP2012/061047 JP2012061047W WO2012153636A1 WO 2012153636 A1 WO2012153636 A1 WO 2012153636A1 JP 2012061047 W JP2012061047 W JP 2012061047W WO 2012153636 A1 WO2012153636 A1 WO 2012153636A1
Authority
WO
WIPO (PCT)
Prior art keywords
insulating layer
polyimide resin
polyimide
resin varnish
conductor
Prior art date
Application number
PCT/JP2012/061047
Other languages
French (fr)
Japanese (ja)
Inventor
吉田　健吾
雅晃 山内
正隆 志波
悠史 畑中
惇一 今井
菅原　潤
清水　亨
齋藤　秀明
雄大 古屋
Original Assignee
住友電工ウインテック株式会社
住友電気工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 住友電工ウインテック株式会社, 住友電気工業株式会社 filed Critical 住友電工ウインテック株式会社
Publication of WO2012153636A1 publication Critical patent/WO2012153636A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K3/00—Details of windings
    • H02K3/30—Windings characterised by the insulating material
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D179/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen, with or without oxygen, or carbon only, not provided for in groups C09D161/00 - C09D177/00
    • C09D179/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
    • C09D179/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/18—Fireproof paints including high temperature resistant paints
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
    • H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
    • H01B3/303—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups H01B3/38 or H01B3/302
    • H01B3/306—Polyimides or polyesterimides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F5/00—Coils
    • H01F5/06—Insulation of windings
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K3/00—Details of windings
    • H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
    • H02K3/18—Windings for salient poles

Definitions

  • the present invention relates to a polyimide resin varnish that can be coated and baked on a conductor to form an insulating film, an insulated wire having an insulating layer formed using this polyimide resin varnish, an electric coil, and a motor using the same.
  • an insulating layer (insulating film) covering the conductor is required to have excellent insulation, adhesion to the conductor, heat resistance, mechanical strength, and the like.
  • the resin forming the insulating layer include polyimide resin, polyamideimide resin, and polyesterimide resin.
  • a high voltage is applied to an insulated wire constituting the electric device, and partial discharge (corona discharge) is likely to occur on the surface of the insulating film.
  • the generation of corona discharge is likely to cause local temperature rise and generation of ozone and ions.
  • Insulated wires used at high voltages are also required to improve the corona discharge starting voltage for the above reasons, and it is known that reducing the dielectric constant of the insulating layer is effective for this purpose.
  • Patent Document 1 discloses an enameled wire in which a polyimide resin enamel film layer is applied and baked directly on a conductor as an enameled wire having a heat resistance class C (class of 180 ° C. or higher).
  • Patent Document 2 describes a polyimide resin having an aromatic ether structure. Specifically, a polyimide by reacting an acid anhydride having an aromatic ether structure such as 4,4′-oxydiphthalic dianhydride (ODPA) with a diamine having an aromatic ether structure and a diamine having a fluorene structure. The precursor is synthesized. The flexibility is improved by using an acid anhydride having an aromatic ether structure and a diamine. Further, it is described that the polyimide resin having such a structure has a low dielectric constant and can provide an insulating film excellent in suppressing corona generation.
  • ODPA 4,4′-oxydiphthalic dianhydride
  • polyimide resin is a material having excellent heat resistance, mechanical properties, and electrical properties, but has a problem of poor workability, particularly wear resistance.
  • the insulated wire is greatly deformed to increase the space factor of the coil. For example, after forming the coil by winding the insulated wire, the coil is inserted into the slot, or the insulated wire deformed in advance is welded to form the coil. If the insulating layer has poor wear resistance, the insulating layer is easily damaged during processing, and the insulating layer may be cracked or pinholed, resulting in poor electrical characteristics.
  • Patent Document 1 a film layer made of polybenzimidazole resin is provided on a polyimide film layer to achieve both heat resistance and wear resistance.
  • the polyimide film is formed by applying and baking a varnish (polyimide resin varnish) obtained by dissolving a polyimide precursor resin in a solvent on a conductor.
  • the polyamic acid which is a polyimide precursor, is imidized by heat during baking to become polyimide. Since only a thin film having a thickness of about several ⁇ m can be formed by a single coating and baking process, a polyimide film having a predetermined thickness (several tens of ⁇ m) is formed by repeating the coating and baking processes a plurality of times.
  • a polyimide resin varnish is applied on the polyimide layer formed in the previous step.
  • the solvent contained in the polyimide resin varnish dissolves the lower layer (polyimide layer formed in the previous step) slightly, so that the compatibility between the layers is improved and the adhesion between the layers is obtained.
  • the baked imidized polyimide is too high in solvent resistance compared to other resins such as polyamideimide, so that the lower layer hardly dissolves when varnish is applied. Accordingly, the adhesion force (adhesive force) between the layers is reduced, and if the processing causes a large deformation in the film, the film is destroyed due to the peeling between the layers.
  • the adhesion between the insulating layer and the conductor is also necessary. If the adhesion between the conductor and the insulating layer is low, floating occurs between the conductor and the insulating layer in the winding process or the process of deforming the insulated wire, and the electrical characteristics deteriorate.
  • the present invention has been made in view of the above problems, and an object thereof is to provide a polyimide resin varnish capable of forming an insulating layer having high interlayer adhesion and adhesion with a conductor and excellent workability. Further, the present invention has an insulating layer formed using the above polyimide resin varnish, an insulated wire that can satisfy required characteristics such as work resistance, heat resistance, mechanical strength, and an electric coil using the same, It is an object to provide a motor.
  • the interlayer adhesion of the polyimide film correlates with the solubility of the polyimide in the solvent.
  • the present inventors paid attention to the imide group concentration of polyimide and found that the solubility in a solvent can be improved by lowering the concentration of a highly polar imide group.
  • a general polyimide resin widely used for a film of an insulated wire is obtained by imidizing a polyimide precursor (polyamic acid) obtained by polymerizing pyromellitic dianhydride and 4,4′-diaminodiphenyl ether.
  • the imide group concentration is 36.6%.
  • the present invention is a polyimide resin varnish mainly composed of a polyimide precursor resin obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride, It is a polyimide resin varnish whose imide group density
  • concentration after the imidation of the said polyimide precursor resin is 28.0% or more and 33.0% or less (Claim 1).
  • the imide group concentration is (Molecular weight of imide group) / (Molecular weight of all polymers) ⁇ 100 (%) It is a value calculated by. Since the polyimide precursor is obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride, the imide group concentration is increased when the molecular weight of each monomer (aromatic diamine or aromatic tetracarboxylic dianhydride) increases. Lower.
  • the imide group concentration is lowered, the solubility of the polyimide after imidization is improved and the interlayer adhesion is improved.
  • the highly polar imide group contributes to the adhesion with the conductor, and the adhesion with the conductor decreases when the imide group concentration decreases.
  • the imide group concentration is adjusted by arbitrarily selecting the aromatic diamine and the aromatic tetracarboxylic dianhydride constituting the polyimide precursor so that the imide group concentration is 28.0% or more and 33.0% or less. .
  • the aromatic tetracarboxylic dianhydride is preferably pyromellitic dianhydride (PMDA) (Claim 2).
  • PMDA pyromellitic dianhydride
  • Pyromellitic dianhydride has a relatively small molecular weight and a rigid structure.
  • aromatic diamine or aromatic tetracarboxylic dianhydride has a large molecular weight
  • aromatic tetracarboxylic dianhydride having a large molecular weight is Since heat resistance decreases when used, it is preferable to select PMDA having a low molecular weight and to adjust the imide group concentration using an aromatic diamine having a high molecular weight because the heat resistance is improved.
  • the aromatic diamine comprises 2,2-bis [4- (aminophenoxy) phenyl] propane, 1,3-bis (4-aminophenoxy) benzene, and 1,4-bis (4-aminophenoxy) benzene. It is preferable to contain 1 or more types selected from the group (Claim 3). These aromatic diamines have a large molecular weight and can reduce the imide group concentration. In particular, when PMDA is selected as the aromatic tetracarboxylic dianhydride, the balance between heat resistance and adhesion is preferred. A plurality of aromatic diamines may be used in combination.
  • the imide group concentration by combining the above-described aromatic diamine having a large molecular weight and an aromatic dian having a small molecular weight such as 4,4'-diaminodiphenyl ether (ODA).
  • aromatic diamine having a large molecular weight and an aromatic dian having a small molecular weight such as 4,4'-diaminodiphenyl ether (ODA).
  • ODA 4,4'-diaminodiphenyl ether
  • Invention of Claim 4 is an insulated wire which has a conductor and the insulating layer which coat
  • the invention according to claim 5 is an insulated wire having an insulating layer that directly covers a conductor, and the insulating layer is formed by repeating the steps of applying and baking the polyimide resin varnish a plurality of times. It is an insulated wire. Since the polyimide resin varnish of the present invention is excellent in adhesion and interlaminar adhesion with a conductor, even with an insulated wire having an insulating layer composed of a plurality of layers of polyimide resin in this manner, adhesion with the conductor Workability is improved due to excellent strength and interlayer adhesion. Moreover, since it is possible to form an insulating layer only with the polyimide which is excellent in heat resistance, the heat resistance of an insulated wire can be improved more.
  • the invention according to claim 6 is an electric coil formed by winding the insulated wire.
  • a seventh aspect of the present invention is a motor having the electric coil according to the sixth aspect. Since an insulated wire excellent in workability and heat resistance is used, a coil with a high space factor can be obtained, and the coil and motor can be downsized. Further, even when a high voltage is applied, the insulating film is hardly deteriorated, so that the life can be extended.
  • the present invention it is possible to provide a polyimide resin varnish capable of forming an insulating layer having high interlayer adhesion and adhesion with a conductor and excellent workability. Moreover, the insulated wire of the present invention is excellent in work resistance and can satisfy required characteristics such as heat resistance and mechanical strength.
  • the polyimide precursor resin (polyamic acid) which is the main component of the polyimide resin varnish of the present invention is obtained by condensation polymerization of an aromatic tetracarboxylic dianhydride and an aromatic diamine. This condensation polymerization reaction can be performed under the same conditions as in the conventional synthesis of a polyimide precursor.
  • aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride (PMDA), 4,4′-oxydiphthalic dianhydride (ODPA), 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride.
  • Anhydride (BPDA), 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride (BTDA), 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, bicyclo (2, 2,2) -Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,2-bis (3 4-dicarboxyxyphenyl) hexafluoropropane dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, etc.
  • pyromellitic dianhydride is preferable because it has a low molecular weight and a rigid structure and can improve the heat resistance of the polyimide resin.
  • Aromatic diamines include 4,4′-diaminodiphenyl ether (ODA), 4,4′-methylenedianiline (MDA), 2,2-bis [4- (aminophenoxy) phenyl] propane (BAPP), 1, 4-bis (4-aminophenoxy) benzene (TPE-Q), 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,1-bis [4- (4-aminophenoxy) phenyl]
  • Examples include cyclohexane (4-APBZ), 1,3-bis (3-aminophenoxy) benzene (3-APB), 1,5-bis (3-aminophenoxy) naphthalene (1,5-BAPN), and the like.
  • 2,2-bis [4- (aminophenoxy) phenyl] propane (BAPP), 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,4-bis (4-aminophenoxy) Benzene (TPE-Q) is preferably used because it has a large molecular weight and can reduce the imide group concentration.
  • the imide group concentration can be adjusted by using these aromatic diamines in combination with an aromatic diamine having a small molecular weight such as ODA and MDA.
  • the aromatic tetracarboxylic dianhydride and the aromatic diamine are selected so that the imide group concentration after imidization is 28.0% or more and 33.0% or less.
  • the imide group concentration is (Molecular weight of imide group) / (Molecular weight of all polymers) ⁇ 100 It is a value calculated by. Specifically, the imide group concentration is calculated by the following method.
  • concentration in a unit unit is calculated from the molecular weight of aromatic tetracarboxylic dianhydride and aromatic diamine.
  • aromatic tetracarboxylic dianhydride and aromatic diamine are mixed and reacted.
  • the reaction proceeds favorably, which is preferable.
  • Each material is mixed and heated to react in an organic solvent to obtain a polyimide precursor resin.
  • an aprotic polar organic solvent such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, ⁇ -butyrolactone can be used. These organic solvents may be used alone or in combination of two or more.
  • the amount of the organic solvent is not particularly limited as long as it is an amount capable of uniformly dispersing the aromatic tetracarboxylic dianhydride and the aromatic diamine, but usually 100 parts by mass per 100 parts by mass of the total amount of these components. Use up to 1000 parts by mass (so that the resin concentration is about 10% to 50%). If the amount of the organic solvent is reduced, the amount of the solid content of the polyimide resin varnish obtained is increased, which is effective for cost reduction.
  • additives such as pigments, dyes, inorganic or organic fillers, lubricants, adhesion improvers, reactive low molecules, compatibilizers, and the like may be added to the polyimide resin varnish.
  • melamine is added as an adhesion improver, adhesion with the conductor can be improved.
  • other resins can be mixed and used within a range not impairing the gist of the present invention.
  • a polyimide resin varnish is applied on a conductor directly or through another layer and baked to form an insulating layer.
  • the polyimide precursor resin is imidized to become polyimide.
  • Application and baking can be performed in the same manner as in the production of a normal insulated wire.
  • an insulating layer is formed by repeating several times of baking in a furnace with a preset temperature of 350 to 500 ° C. for 5 to 10 seconds per pass. The thickness of the insulating layer is 10 ⁇ m to 150 ⁇ m.
  • the conductor copper, copper alloy, aluminum, or the like can be used.
  • the size of the conductor and the cross-sectional shape thereof are not particularly limited, but in the case of a round wire, a conductor diameter of 100 ⁇ m to 5 mm is generally used, and in the case of a flat wire, one having a side length of 500 ⁇ m to 5 mm is generally used.
  • the insulating layer may be a single layer or multiple layers.
  • the insulating layer is a single layer, only the insulating layer formed by applying and baking the above polyimide resin varnish becomes the insulating layer.
  • the insulating layer has a multilayer structure, another insulating layer is formed before or after the formation of the insulating layer made of polyimide.
  • the resin for forming the other insulating layer any resin such as polyimide, polyamideimide, polyesterimide, polyurethane, and polyetherimide can be used.
  • the outermost layer has a surface lubricating layer as the insulating layer because the workability is further improved. Moreover, you may apply
  • FIG. 1 is a schematic sectional view showing an example of an insulated wire of the present invention.
  • a multi-layer insulating layer is provided outside the conductor 3, and the insulating layers are a first insulating layer 1 and a second insulating layer 2 from the conductor side.
  • the first insulating layer 1 and the second insulating layer 2 are all formed by applying and baking the polyamide-imide resin varnish of the present invention, an insulated wire having excellent heat resistance and excellent adhesion to conductors and interlayer adhesion is obtained. can get. Further, in order to further improve the adhesion with the conductor, other resins such as polyamideimide may be used as the first insulating layer 1.
  • the insulated wire of the present invention is not limited to this shape.
  • FIG. 2 (a) is a schematic view showing an example of the electric coil of the present invention
  • FIG. 2 (b) is a cross-sectional view taken along the line A-A 'of FIG. 2 (a).
  • the electric wire 12 is formed by winding the insulated wire 11 outside the core 13 made of a magnetic material.
  • a member composed of a core and an electric coil is used as a rotor or a stator of a motor.
  • a stator 15 in which a plurality of divided stators 14 each composed of a core 13 and an electric coil 12 are combined and arranged in an annular shape is used as a constituent member of a motor.
  • An insulating layer having a thickness of about 40 ⁇ m was formed on the surface of a flat conductor having a thickness of 1.5 mm and a width of 3.0 mm by repeating the steps of applying and baking the produced polyimide resin varnish by a conventional method several times. Insulated wires of Comparative Examples 1 to 5 were produced.
  • Examples 1 to 3 and Comparative Examples 1 to 3 ODA having a low molecular weight and BAPP having a high molecular weight are used in combination as an aromatic diamine, and the ratio of BAPP (modified amount of long-chain diamine in the table) is 0% to 100%.
  • the imide group concentration was adjusted by changing. The higher the BAPP ratio and the lower the imide group concentration, the higher the interlayer adhesion. Further, the conductor adhesion is lower as the imide group concentration is lower.
  • the imide group concentration is 28.0% or more and 33.0% or less
  • both the conductor adhesion strength and the interlayer adhesion strength are 50 g / mm or more, and it is estimated that the workability is good.

Abstract

Provided is a polyimide resin varnish capable of forming an insulating layer having high inter-layer adhesion, high adhesion to a conductor, and excellent processing resistance. Also provided is an insulated electric wire having excellent processing resistance, heat resistance, and mechanical properties. The polyimide resin varnish has as the main component thereof a polyimide precursor resin obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride. The imide group concentration of the polyimide precursor resin after imidization is 28.0%-33.0%.

Description

ポリイミド樹脂ワニス及びそれを用いた絶縁電線、電機コイル、モータPolyimide resin varnish and insulated wires, electric coils, and motors using the same
　本発明は導体に塗布、焼付けして絶縁皮膜を形成することができるポリイミド樹脂ワニス、及びこのポリイミド樹脂ワニスを用いて形成された絶縁層を有する絶縁電線およびそれを用いた電機コイル、モータに関する。 The present invention relates to a polyimide resin varnish that can be coated and baked on a conductor to form an insulating film, an insulated wire having an insulating layer formed using this polyimide resin varnish, an electric coil, and a motor using the same.
　モータ等のコイル用巻線として用いられる絶縁電線において、導体を被覆する絶縁層（絶縁皮膜）には、優れた絶縁性、導体に対する密着性、耐熱性、機械的強度等が求められている。絶縁層を形成する樹脂としてはポリイミド樹脂、ポリアミドイミド樹脂、ポリエステルイミド樹脂等がある。 In an insulated wire used as a coil winding for a motor or the like, an insulating layer (insulating film) covering the conductor is required to have excellent insulation, adhesion to the conductor, heat resistance, mechanical strength, and the like. Examples of the resin forming the insulating layer include polyimide resin, polyamideimide resin, and polyesterimide resin.
　また適用電圧が高い電気機器、例えば高電圧で使用されるモータ等では、電気機器を構成する絶縁電線に高電圧が印加され、その絶縁皮膜表面で部分放電（コロナ放電）が発生しやすくなる。コロナ放電の発生により局部的な温度上昇やオゾンやイオンの発生が引き起こされやすくなり、その結果絶縁電線の絶縁被膜に劣化が生じることで早期に絶縁破壊を起こし、電気機器の寿命が短くなる。高電圧で使用される絶縁電線には上記の理由によりコロナ放電開始電圧の向上も求められており、そのためには絶縁層の誘電率を低くすることが有効であることが知られている。 In addition, in an electric device having a high applied voltage, for example, a motor used at a high voltage, a high voltage is applied to an insulated wire constituting the electric device, and partial discharge (corona discharge) is likely to occur on the surface of the insulating film. The generation of corona discharge is likely to cause local temperature rise and generation of ozone and ions. As a result, the insulation coating of the insulated wire is deteriorated, resulting in early dielectric breakdown and shortening the life of the electric equipment. Insulated wires used at high voltages are also required to improve the corona discharge starting voltage for the above reasons, and it is known that reducing the dielectric constant of the insulating layer is effective for this purpose.
　ポリイミド樹脂は絶縁電線の絶縁層として汎用されている樹脂の中では特に耐熱性に優れている。また誘電率が低く機械特性にも優れるため、要求特性の高い絶縁電線の絶縁層として用いられている。たとえば特許文献１には耐熱区分がＣ種（１８０℃以上のクラス）のエナメル線として、導体直上にポリイミド樹脂エナメル皮膜層が塗布焼付けされているエナメル線が開示されている。 Polyimide resin is particularly excellent in heat resistance among resins widely used as an insulating layer for insulated wires. Moreover, since it has a low dielectric constant and excellent mechanical properties, it is used as an insulating layer for insulated wires with high required properties. For example, Patent Document 1 discloses an enameled wire in which a polyimide resin enamel film layer is applied and baked directly on a conductor as an enameled wire having a heat resistance class C (class of 180 ° C. or higher).
　また特許文献２には芳香族エーテル構造を有するポリイミド樹脂が記載されている。具体的には、４，４’－オキシジフタル酸二無水物（ＯＤＰＡ）等の芳香族エーテル構造を有する酸無水物と、芳香族エーテル構造を有するジアミン及びフルオレン構造を有するジアミンとを反応させてポリイミド前駆体を合成している。芳香族エーテル構造を有する酸無水物及びジアミンを用いることで可とう性を向上している。またこのような構造のポリイミド樹脂は低誘電率でありコロナ発生抑制に優れた絶縁皮膜を得ることができる、と記載されている。 Patent Document 2 describes a polyimide resin having an aromatic ether structure. Specifically, a polyimide by reacting an acid anhydride having an aromatic ether structure such as 4,4′-oxydiphthalic dianhydride (ODPA) with a diamine having an aromatic ether structure and a diamine having a fluorene structure. The precursor is synthesized. The flexibility is improved by using an acid anhydride having an aromatic ether structure and a diamine. Further, it is described that the polyimide resin having such a structure has a low dielectric constant and can provide an insulating film excellent in suppressing corona generation.
特開平９－１９８９３２号公報JP-A-9-198932 特開２０１０－６７４０８号公報JP 2010-67408 A
　上記のようにポリイミド樹脂は耐熱性、機械的特性、電気特性に優れる材料であるが、耐加工性、特に耐摩耗性が悪いという問題がある。絶縁電線をコイルとして使用する際には、コイルの占積率を上げるために絶縁電線を大きく変形させる加工を行う。例えば絶縁電線を捲線してコイルを形成した後にコイルをスロット中に挿入したり、あらかじめ変形させた絶縁電線同士を溶接してコイルを形成したりする。絶縁層の耐摩耗性が悪いと、加工時に絶縁層が損傷を受けやすく、絶縁層に割れやピンホールが発生して電気特性が不良となるおそれがある。 As described above, polyimide resin is a material having excellent heat resistance, mechanical properties, and electrical properties, but has a problem of poor workability, particularly wear resistance. When using an insulated wire as a coil, the insulated wire is greatly deformed to increase the space factor of the coil. For example, after forming the coil by winding the insulated wire, the coil is inserted into the slot, or the insulated wire deformed in advance is welded to form the coil. If the insulating layer has poor wear resistance, the insulating layer is easily damaged during processing, and the insulating layer may be cracked or pinholed, resulting in poor electrical characteristics.
　特に最外層にポリイミド皮膜を有する絶縁電線で耐加工性が低下することが知られている。そのためポリイミドを絶縁層として用いる場合、最外層には別の樹脂からなる層を設けることが多い。特許文献１ではポリイミド皮膜層上にポリベンズイミダゾール樹脂からなる皮膜層を設けて耐熱性と耐摩耗性を両立している。 Especially, it is known that the workability is lowered in an insulated wire having a polyimide film as the outermost layer. Therefore, when polyimide is used as the insulating layer, a layer made of another resin is often provided as the outermost layer. In Patent Document 1, a film layer made of polybenzimidazole resin is provided on a polyimide film layer to achieve both heat resistance and wear resistance.
　ポリイミドの耐加工性が低下する一つの要因は、ポリイミド皮膜の耐溶剤性が高いことである。ポリイミド皮膜は、ポリイミド前駆体樹脂を溶剤に溶解したワニス（ポリイミド樹脂ワニス）を導体上に塗布、焼付けして形成する。焼付け時の熱によってポリイミド前駆体であるポリアミック酸がイミド化してポリイミドとなる。一度の塗布、焼付け工程では数μｍ程度の薄い皮膜しか形成できないため、塗布、焼付け工程を複数回繰り返して所定の厚み（数１０μｍ程度）のポリイミド皮膜を形成する。そのため２回目以降の工程では前回の工程で形成されたポリイミド層の上にポリイミド樹脂ワニスを塗布することとなる。この時、ポリイミド樹脂ワニスに含まれる溶剤が下層（前回の工程で形成されたポリイミド層）を若干溶解することで層間のなじみが良くなり層間の密着力が得られる。しかし焼付けてイミド化したポリイミドはポリアミドイミド等の他の樹脂と比べると耐溶剤性が高すぎるためワニスを塗布した際に下層がほとんど溶解しない。従って層間の密着力（接着力）が低下し、皮膜に大きな変形を起こすような加工を行うと層間の剥離に起因して皮膜が破壊される。 One factor that decreases the processability of polyimide is the high solvent resistance of the polyimide film. The polyimide film is formed by applying and baking a varnish (polyimide resin varnish) obtained by dissolving a polyimide precursor resin in a solvent on a conductor. The polyamic acid, which is a polyimide precursor, is imidized by heat during baking to become polyimide. Since only a thin film having a thickness of about several μm can be formed by a single coating and baking process, a polyimide film having a predetermined thickness (several tens of μm) is formed by repeating the coating and baking processes a plurality of times. Therefore, in the second and subsequent steps, a polyimide resin varnish is applied on the polyimide layer formed in the previous step. At this time, the solvent contained in the polyimide resin varnish dissolves the lower layer (polyimide layer formed in the previous step) slightly, so that the compatibility between the layers is improved and the adhesion between the layers is obtained. However, the baked imidized polyimide is too high in solvent resistance compared to other resins such as polyamideimide, so that the lower layer hardly dissolves when varnish is applied. Accordingly, the adhesion force (adhesive force) between the layers is reduced, and if the processing causes a large deformation in the film, the film is destroyed due to the peeling between the layers.
　また耐加工性を上げるためには絶縁層と導体との密着力も必要である。導体と絶縁層との密着力が低いと、捲線工程や絶縁電線を変形させる工程で導体と絶縁層との間に浮きが発生して電気特性が悪化する。 Also, in order to improve the work resistance, the adhesion between the insulating layer and the conductor is also necessary. If the adhesion between the conductor and the insulating layer is low, floating occurs between the conductor and the insulating layer in the winding process or the process of deforming the insulated wire, and the electrical characteristics deteriorate.
　本発明は上記の問題に鑑みてなされたものであり、層間密着力及び導体との密着力が高く耐加工性に優れる絶縁層を形成可能なポリイミド樹脂ワニスを提供することを課題とする。また本発明は上記のポリイミド樹脂ワニスを用いて形成された絶縁層を有し、耐加工性、耐熱性、機械的強度等の要求特性を満たすことのできる絶縁電線及びそれを用いた電機コイル、モータを提供することを課題とする。 The present invention has been made in view of the above problems, and an object thereof is to provide a polyimide resin varnish capable of forming an insulating layer having high interlayer adhesion and adhesion with a conductor and excellent workability. Further, the present invention has an insulating layer formed using the above polyimide resin varnish, an insulated wire that can satisfy required characteristics such as work resistance, heat resistance, mechanical strength, and an electric coil using the same, It is an object to provide a motor.
　上記のようにポリイミド皮膜の層間密着力はポリイミドの溶剤への溶解性と相関する。本発明者らはポリイミドのイミド基濃度に着目し、極性の高いイミド基の濃度を下げることで溶剤への溶解性を向上できることを見いだした。なお絶縁電線の皮膜に汎用されている一般的なポリイミド樹脂はピロメリット酸二無水物と４，４’－ジアミノジフェニルエーテルとを重合して得られるポリイミド前駆体（ポリアミック酸）をイミド化して得られるもので、イミド基濃度は３６．６％である。 As mentioned above, the interlayer adhesion of the polyimide film correlates with the solubility of the polyimide in the solvent. The present inventors paid attention to the imide group concentration of polyimide and found that the solubility in a solvent can be improved by lowering the concentration of a highly polar imide group. In addition, a general polyimide resin widely used for a film of an insulated wire is obtained by imidizing a polyimide precursor (polyamic acid) obtained by polymerizing pyromellitic dianhydride and 4,4′-diaminodiphenyl ether. The imide group concentration is 36.6%.
　本発明は、芳香族ジアミンと芳香族テトラカルボン酸二無水物とを反応して得られるポリイミド前駆体樹脂を主成分とするポリイミド樹脂ワニスであって、
前記ポリイミド前駆体樹脂のイミド化後のイミド基濃度が２８．０％以上３３．０％以下である、ポリイミド樹脂ワニスである（請求項１）。 The present invention is a polyimide resin varnish mainly composed of a polyimide precursor resin obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride,
It is a polyimide resin varnish whose imide group density | concentration after the imidation of the said polyimide precursor resin is 28.0% or more and 33.0% or less (Claim 1).
　イミド基濃度は、ポリイミド前駆体をイミド化した後のポリイミド樹脂において、
　（イミド基部分の分子量）／（全ポリマーの分子量）×１００　（％）
で計算される値である。ポリイミド前駆体は芳香族ジアミンと芳香族テトラカルボン酸二無水物とを反応して得られるので、各モノマー（芳香族ジアミン又は芳香族テトラカルボン酸二無水物）の分子量が大きくなるとイミド基濃度は低くなる。 In the polyimide resin after imidizing the polyimide precursor, the imide group concentration is
(Molecular weight of imide group) / (Molecular weight of all polymers) × 100 (%)
It is a value calculated by. Since the polyimide precursor is obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride, the imide group concentration is increased when the molecular weight of each monomer (aromatic diamine or aromatic tetracarboxylic dianhydride) increases. Lower.
　イミド基濃度を低くするとイミド化後のポリイミドの溶解性が向上し、層間密着力が向上する。しかし極性の高いイミド基は導体との密着力に寄与しており、イミド基濃度が低下すると導体との密着力が低下する。イミド基濃度を２８．０％以上３３．０％以下とすることで、層間密着力と導体との密着力とを両立できる。ポリイミド前駆体を構成する芳香族ジアミンと芳香族テトラカルボン酸二無水物とを、イミド基濃度が２８．０％以上３３．０％以下となるように任意に選択してイミド基濃度を調整する。 If the imide group concentration is lowered, the solubility of the polyimide after imidization is improved and the interlayer adhesion is improved. However, the highly polar imide group contributes to the adhesion with the conductor, and the adhesion with the conductor decreases when the imide group concentration decreases. By adjusting the imide group concentration to 28.0% or more and 33.0% or less, it is possible to achieve both interlayer adhesion and adhesion with the conductor. The imide group concentration is adjusted by arbitrarily selecting the aromatic diamine and the aromatic tetracarboxylic dianhydride constituting the polyimide precursor so that the imide group concentration is 28.0% or more and 33.0% or less. .
　前記芳香族テトラカルボン酸二無水物はピロメリット酸二無水物（ＰＭＤＡ）であると好ましい（請求項２）。ピロメリット酸二無水物は比較的分子量が小さく剛直な構造である。イミド基濃度を調整するためには、芳香族ジアミン、芳香族テトラカルボン酸二無水物のいずれかを分子量の大きいものとすることが考えられるが、分子量の大きい芳香族テトラカルボン酸二無水物を使用すると耐熱性が低下するため、酸成分は分子量の小さいＰＭＤＡを選択し、分子量の大きい芳香族ジアミンを用いてイミド基濃度を調整する方が耐熱性が向上し、好ましい。 The aromatic tetracarboxylic dianhydride is preferably pyromellitic dianhydride (PMDA) (Claim 2). Pyromellitic dianhydride has a relatively small molecular weight and a rigid structure. In order to adjust the imide group concentration, it is considered that either aromatic diamine or aromatic tetracarboxylic dianhydride has a large molecular weight, but aromatic tetracarboxylic dianhydride having a large molecular weight is Since heat resistance decreases when used, it is preferable to select PMDA having a low molecular weight and to adjust the imide group concentration using an aromatic diamine having a high molecular weight because the heat resistance is improved.
　前記芳香族ジアミンとして、２，２－ビス［４－（アミノフェノキシ）フェニル］プロパン、１，３－ビス（４－アミノフェノキシ）ベンゼン、及び１，４－ビス（４－アミノフェノキシ）ベンゼンからなる群から選択される１種以上を含有することが好ましい（請求項３）。これらの芳香族ジアミンは分子量が大きく、イミド基濃度を低くすることができる。特に芳香族テトラカルボン酸二無水物としてＰＭＤＡを選択した場合には耐熱性と密着力とのバランスが取れて好ましい。なお芳香族ジアミンは複数併用しても良い。この場合、上記の分子量の大きい芳香族ジアミンと、４，４’－ジアミノジフェニルエーテル（ＯＤＡ）等の分子量の小さい芳香族ジアンとを組み合わせてイミド基濃度を調整することが好ましい。 The aromatic diamine comprises 2,2-bis [4- (aminophenoxy) phenyl] propane, 1,3-bis (4-aminophenoxy) benzene, and 1,4-bis (4-aminophenoxy) benzene. It is preferable to contain 1 or more types selected from the group (Claim 3). These aromatic diamines have a large molecular weight and can reduce the imide group concentration. In particular, when PMDA is selected as the aromatic tetracarboxylic dianhydride, the balance between heat resistance and adhesion is preferred. A plurality of aromatic diamines may be used in combination. In this case, it is preferable to adjust the imide group concentration by combining the above-described aromatic diamine having a large molecular weight and an aromatic dian having a small molecular weight such as 4,4'-diaminodiphenyl ether (ODA).
　請求項４に記載の発明は、導体及び該導体を直接又は他の層を介して被覆する絶縁層を有する絶縁電線であって、前記絶縁層は上記のポリイミド樹脂ワニスを塗布、焼付けして形成されたものである絶縁電線である。層間密着力に優れたポリイミドで形成された絶縁層を有するため、耐加工性及び耐熱性に優れた絶縁電線が得られる。また絶縁層の誘電率が低いため、コロナ放電開始電圧の高い絶縁電線が得られる。 Invention of Claim 4 is an insulated wire which has a conductor and the insulating layer which coat | covers this conductor directly or through another layer, Comprising: The said insulating layer is formed by apply | coating and baking said polyimide resin varnish It is the insulated wire which is made. Since it has an insulating layer formed of polyimide having excellent interlayer adhesion, an insulated wire excellent in process resistance and heat resistance can be obtained. Further, since the dielectric constant of the insulating layer is low, an insulated wire having a high corona discharge starting voltage can be obtained.
　請求項５に記載の発明は、導体を直接被覆する絶縁層を有する絶縁電線であって、前記絶縁層は上記のポリイミド樹脂ワニスを塗布、焼付けする工程を複数回繰り返して形成されたものである絶縁電線である。本発明のポリイミド樹脂ワニスは導体との密着力と層間密着力に優れているため、このような態様により複数層のポリイミド樹脂からなる絶縁層を備えた絶縁電線であっても、導体との密着力及び層間密着力が優れているため耐加工性が向上する。また耐熱性に優れるポリイミドのみで絶縁層を形成することが可能であるので、絶縁電線の耐熱性をより向上することができる。 The invention according to claim 5 is an insulated wire having an insulating layer that directly covers a conductor, and the insulating layer is formed by repeating the steps of applying and baking the polyimide resin varnish a plurality of times. It is an insulated wire. Since the polyimide resin varnish of the present invention is excellent in adhesion and interlaminar adhesion with a conductor, even with an insulated wire having an insulating layer composed of a plurality of layers of polyimide resin in this manner, adhesion with the conductor Workability is improved due to excellent strength and interlayer adhesion. Moreover, since it is possible to form an insulating layer only with the polyimide which is excellent in heat resistance, the heat resistance of an insulated wire can be improved more.
　請求項６に記載の発明は、上記の絶縁電線を捲線してなる電機コイルである。また請求項７に記載の発明は、請求項６に記載の電機コイルを有するモータである。耐加工性及び耐熱性に優れた絶縁電線を使用していることから占積率の高いコイルが得られ、コイル及びモータの小型化が可能となる。また高電圧が印加された場合でも絶縁皮膜の劣化が起こりにくいので、寿命を長くすることが可能である。 The invention according to claim 6 is an electric coil formed by winding the insulated wire. A seventh aspect of the present invention is a motor having the electric coil according to the sixth aspect. Since an insulated wire excellent in workability and heat resistance is used, a coil with a high space factor can be obtained, and the coil and motor can be downsized. Further, even when a high voltage is applied, the insulating film is hardly deteriorated, so that the life can be extended.
　本発明によれば、層間密着力及び導体との密着力が高く耐加工性に優れる絶縁層を形成可能なポリイミド樹脂ワニスを提供することができる。また本発明の絶縁電線は耐加工性に優れ、耐熱性、機械強度等の要求特性を満たすことができる。 According to the present invention, it is possible to provide a polyimide resin varnish capable of forming an insulating layer having high interlayer adhesion and adhesion with a conductor and excellent workability. Moreover, the insulated wire of the present invention is excellent in work resistance and can satisfy required characteristics such as heat resistance and mechanical strength.
本発明の絶縁電線の一例を示す断面模式図である。It is a cross-sectional schematic diagram which shows an example of the insulated wire of this invention. 本発明のコイルの一例を示す模式図である。It is a schematic diagram which shows an example of the coil of this invention. 本発明のモータの一例を示す模式図である。It is a schematic diagram which shows an example of the motor of this invention.
　本発明のポリイミド樹脂ワニスの主成分であるポリイミド前駆体樹脂（ポリアミック酸）は、芳香族テトラカルボン酸二無水物と芳香族ジアミンとの縮合重合によって得られる。この縮合重合反応は従来のポリイミド前駆体の合成と同様な条件にて行うことができる。 The polyimide precursor resin (polyamic acid) which is the main component of the polyimide resin varnish of the present invention is obtained by condensation polymerization of an aromatic tetracarboxylic dianhydride and an aromatic diamine. This condensation polymerization reaction can be performed under the same conditions as in the conventional synthesis of a polyimide precursor.
　芳香族テトラカルボン酸二無水物としては、ピロメリット酸二無水物（ＰＭＤＡ）、４，４’－オキシジフタル酸二無水物（ＯＤＰＡ）、３，４，３’，４’－ビフェニルテトラカルボン酸二無水物（ＢＰＤＡ）、３，３’，４，４’－ベンゾフェノンテトラカルボン酸二無水物（ＢＴＤＡ）、３，３’，４，４’－ジフェニルスルホンテトラカルボン酸二無水物、ビシクロ（２，２，２）－オクト－７－エン－２，３，５，６－テトラカルボン酸二無水物、１，２，４，５－シクロヘキサンテトラカルボン酸二無水物、２，２－ビス（３，４－ジカルボンキシフェニル）ヘキサフルオロプロパン二無水物、５－（２，５－ジオキソテトラヒドロフリル）－３－メチル－３－シクロヘキセン－１，２－ジカルボン酸二無水物等が例示される。 Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride (PMDA), 4,4′-oxydiphthalic dianhydride (ODPA), 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride. Anhydride (BPDA), 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride (BTDA), 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, bicyclo (2, 2,2) -Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,2-bis (3 4-dicarboxyxyphenyl) hexafluoropropane dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, etc.
　この中でもピロメリット酸二無水物（ＰＭＤＡ）は低分子量で剛直な構造を持つため、ポリイミド樹脂の耐熱性を向上できる点で好ましい。 Among these, pyromellitic dianhydride (PMDA) is preferable because it has a low molecular weight and a rigid structure and can improve the heat resistance of the polyimide resin.
　芳香族ジアミンとしては、４，４’－ジアミノジフェニルエーテル（ＯＤＡ）、４，４’－メチレンジアニリン（ＭＤＡ）、２，２－ビス［４－（アミノフェノキシ）フェニル］プロパン（ＢＡＰＰ）、１，４－ビス（４－アミノフェノキシ）ベンゼン（ＴＰＥ－Ｑ）、１，３－ビス（４－アミノフェノキシ）ベンゼン（ＴＰＥ－Ｒ）、１，１－ビス［４－（４－アミノフェノキシ）フェニル］シクロヘキサン（４－ＡＰＢＺ）、１，３－ビス（３－アミノフェノキシ）ベンゼン（３－ＡＰＢ）、１，５－ビス（３－アミノフェノキシ）ナフタレン（１，５－ＢＡＰＮ）等が例示される。 Aromatic diamines include 4,4′-diaminodiphenyl ether (ODA), 4,4′-methylenedianiline (MDA), 2,2-bis [4- (aminophenoxy) phenyl] propane (BAPP), 1, 4-bis (4-aminophenoxy) benzene (TPE-Q), 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,1-bis [4- (4-aminophenoxy) phenyl] Examples include cyclohexane (4-APBZ), 1,3-bis (3-aminophenoxy) benzene (3-APB), 1,5-bis (3-aminophenoxy) naphthalene (1,5-BAPN), and the like.
　この中でも２，２－ビス［４－（アミノフェノキシ）フェニル］プロパン（ＢＡＰＰ）、１，３－ビス（４－アミノフェノキシ）ベンゼン（ＴＰＥ－Ｒ）、１，４－ビス（４－アミノフェノキシ）ベンゼン（ＴＰＥ－Ｑ）は分子量が大きく、イミド基濃度を低減できるため好ましく使用できる。これらの芳香族ジアミンとＯＤＡ、ＭＤＡ等の分子量の小さい芳香族ジアミンとを組み合わせて使用することで、イミド基濃度を調整できる。 Among these, 2,2-bis [4- (aminophenoxy) phenyl] propane (BAPP), 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,4-bis (4-aminophenoxy) Benzene (TPE-Q) is preferably used because it has a large molecular weight and can reduce the imide group concentration. The imide group concentration can be adjusted by using these aromatic diamines in combination with an aromatic diamine having a small molecular weight such as ODA and MDA.
　芳香族テトラカルボン酸二無水物、芳香族ジアミンは、イミド化後のイミド基濃度が２８．０％以上３３．０％以下となるように選択する。イミド基濃度はポリイミド前駆体をイミド化した後のポリイミド樹脂において、
　（イミド基部分の分子量）／（全ポリマーの分子量）×１００
で計算される値である。具体的には以下の方法でイミド基濃度を計算する。 The aromatic tetracarboxylic dianhydride and the aromatic diamine are selected so that the imide group concentration after imidization is 28.0% or more and 33.0% or less. In the polyimide resin after imidizing the polyimide precursor, the imide group concentration is
(Molecular weight of imide group) / (Molecular weight of all polymers) × 100
It is a value calculated by. Specifically, the imide group concentration is calculated by the following method.
　芳香族テトラカルボン酸二無水物、芳香族ジアミンの分子量からユニット単位でのイミド基濃度を計算する。例えば下記式（１）で示されるポリイミドの場合、イミド基濃度は
イミド基分子量＝７０．０３×２＝１４０．０６
ユニット分子量＝８９４．９６となるため、
イミド基濃度（％）＝（１４０．０６）／（８９４．９６）×１００＝１５．６％
となる。 The imide group density | concentration in a unit unit is calculated from the molecular weight of aromatic tetracarboxylic dianhydride and aromatic diamine. For example, in the case of polyimide represented by the following formula (1), the imide group concentration is imide group molecular weight = 70.03 x 2 = 140.06.
Since unit molecular weight = 894.96,
Imide group concentration (%) = (140.06) / (894.96) × 100 = 15.6%
It becomes.
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
　上記の芳香族テトラカルボン酸二無水物と芳香族ジアミンを混合して反応させる。芳香族ジアミンの合計量（当量）と、芳香族テトラカルボン酸二無水物の合計量（当量）を約１：１とすると反応が良好に進行して好ましい。それぞれの材料を混合し、有機溶媒中で加熱して反応させてポリイミド前駆体樹脂を得る。 The above aromatic tetracarboxylic dianhydride and aromatic diamine are mixed and reacted. When the total amount (equivalent) of aromatic diamine and the total amount (equivalent) of aromatic tetracarboxylic dianhydride is about 1: 1, the reaction proceeds favorably, which is preferable. Each material is mixed and heated to react in an organic solvent to obtain a polyimide precursor resin.
　有機溶媒としては、Ｎ－メチル－２－ピロリドン、Ｎ，Ｎ－ジメチルホルムアミド、Ｎ，Ｎ－ジメチルアセトアミド、ジメチルスルホキシド、γ－ブチロラクトン等の非プロトン性極性有機溶媒が使用できる。これらの有機溶媒は単独で用いても２種以上を組み合わせても良い。 As the organic solvent, an aprotic polar organic solvent such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone can be used. These organic solvents may be used alone or in combination of two or more.
　有機溶媒の量は、芳香族テトラカルボン酸二無水物、芳香族ジアミンを均一に分散させることができる量であれば良く特に制限されないが、通常これらの成分の合計量１００質量部あたり１００質量部～１０００質量部（樹脂濃度で１０％～５０％程度となるように）使用する。有機溶媒量を少なくするとできあがったポリイミド樹脂ワニスの固形分量が多くなりコスト低減に有効である。 The amount of the organic solvent is not particularly limited as long as it is an amount capable of uniformly dispersing the aromatic tetracarboxylic dianhydride and the aromatic diamine, but usually 100 parts by mass per 100 parts by mass of the total amount of these components. Use up to 1000 parts by mass (so that the resin concentration is about 10% to 50%). If the amount of the organic solvent is reduced, the amount of the solid content of the polyimide resin varnish obtained is increased, which is effective for cost reduction.
　ポリイミド樹脂ワニスには顔料、染料、無機又は有機のフィラー、潤滑剤、密着向上剤等の各種添加剤や反応性低分子、相溶化剤等を添加しても良い。密着向上剤としてメラミンを添加すると、導体との密着力を向上できる。さらに本発明の趣旨を損ねない範囲で他の樹脂を混合して使用することもできる。 Various additives such as pigments, dyes, inorganic or organic fillers, lubricants, adhesion improvers, reactive low molecules, compatibilizers, and the like may be added to the polyimide resin varnish. When melamine is added as an adhesion improver, adhesion with the conductor can be improved. Furthermore, other resins can be mixed and used within a range not impairing the gist of the present invention.
　ポリイミド樹脂ワニスを導体上に直接又は他の層を介して塗布、焼き付けして絶縁層を形成する。焼付け工程でポリイミド前駆体樹脂がイミド化してポリイミドとなる。塗布、焼付けは通常の絶縁電線の製造と同様に行うことができる。例えば、導体に樹脂ワニスを塗布した後、設定温度を３５０～５００℃とした炉内を１パス当たり５～１０秒間通過させて焼付ける作業を数回繰り返して絶縁層を形成する。絶縁層の厚みは１０μｍ～１５０μｍとする。 A polyimide resin varnish is applied on a conductor directly or through another layer and baked to form an insulating layer. In the baking step, the polyimide precursor resin is imidized to become polyimide. Application and baking can be performed in the same manner as in the production of a normal insulated wire. For example, after applying a resin varnish to the conductor, an insulating layer is formed by repeating several times of baking in a furnace with a preset temperature of 350 to 500 ° C. for 5 to 10 seconds per pass. The thickness of the insulating layer is 10 μm to 150 μm.
　導体としては、銅や銅合金、アルミニウム等を使用できる。導体の大きさやその断面形状は特に限定されないが、丸線の場合は導体径が１００μｍ～５ｍｍのものが、平角線の場合は一辺の長さが５００μｍ～５ｍｍのものが一般に使用される。 As the conductor, copper, copper alloy, aluminum, or the like can be used. The size of the conductor and the cross-sectional shape thereof are not particularly limited, but in the case of a round wire, a conductor diameter of 100 μm to 5 mm is generally used, and in the case of a flat wire, one having a side length of 500 μm to 5 mm is generally used.
　絶縁層は単層であっても多層であっても良い。絶縁層が単層である場合は上記のポリイミド樹脂ワニスを塗布、焼き付けして形成された絶縁層のみが絶縁層となる。絶縁層を多層にする場合は、上記のポリイミドからなる絶縁層の形成前又は形成後に他の絶縁層を形成する。他の絶縁層を形成する樹脂としてはポリイミド、ポリアミドイミド、ポリエステルイミド、ポリウレタン、ポリエーテルイミド等任意の樹脂を使用できる。 The insulating layer may be a single layer or multiple layers. When the insulating layer is a single layer, only the insulating layer formed by applying and baking the above polyimide resin varnish becomes the insulating layer. When the insulating layer has a multilayer structure, another insulating layer is formed before or after the formation of the insulating layer made of polyimide. As the resin for forming the other insulating layer, any resin such as polyimide, polyamideimide, polyesterimide, polyurethane, and polyetherimide can be used.
　さらに、絶縁層として、最外層に表面潤滑層を有するとさらに加工性が向上して好ましい。また絶縁電線の外側に表面潤滑油を塗布しても良い。この場合はさらにインサート性や加工性が向上する。 Furthermore, it is preferable that the outermost layer has a surface lubricating layer as the insulating layer because the workability is further improved. Moreover, you may apply | coat surface lubricating oil to the outer side of an insulated wire. In this case, insertability and workability are further improved.
　図１は本発明の絶縁電線の一例を示す断面模式図である。導体３の外側に多層の絶縁層があり、絶縁層は導体側から第１の絶縁層１、第２の絶縁層２としている。第１の絶縁層１、第２の絶縁層２を全て本発明のポリアミドイミド樹脂ワニスを塗布焼き付けして形成すると、耐熱性に優れると共に導体との密着力、層間密着力に優れた絶縁電線が得られる。また導体との密着力をさらに向上するために、第１の絶縁層１としてポリアミドイミド等の他の樹脂を使用しても良い。なお本発明の絶縁電線はこの形状に限定されるものではない。 FIG. 1 is a schematic sectional view showing an example of an insulated wire of the present invention. A multi-layer insulating layer is provided outside the conductor 3, and the insulating layers are a first insulating layer 1 and a second insulating layer 2 from the conductor side. When the first insulating layer 1 and the second insulating layer 2 are all formed by applying and baking the polyamide-imide resin varnish of the present invention, an insulated wire having excellent heat resistance and excellent adhesion to conductors and interlayer adhesion is obtained. can get. Further, in order to further improve the adhesion with the conductor, other resins such as polyamideimide may be used as the first insulating layer 1. The insulated wire of the present invention is not limited to this shape.
　図２（ａ）は本発明の電機コイルの一例を示す模式図であり、図２（ｂ）は図２（ａ）のＡ－Ａ’断面図である。磁性材料からなるコア１３の外側に絶縁電線１１を捲線して電機コイル１２が形成される。コアと電機コイルからなる部材は、モータのロータやステータとして使用される。例えば、図３に示すように、コア１３と電機コイル１２とからなる分割ステータ１４を複数組み合わせて環状に配置したステータ１５を、モータの構成部材として使用する。 FIG. 2 (a) is a schematic view showing an example of the electric coil of the present invention, and FIG. 2 (b) is a cross-sectional view taken along the line A-A 'of FIG. 2 (a). The electric wire 12 is formed by winding the insulated wire 11 outside the core 13 made of a magnetic material. A member composed of a core and an electric coil is used as a rotor or a stator of a motor. For example, as shown in FIG. 3, a stator 15 in which a plurality of divided stators 14 each composed of a core 13 and an electric coil 12 are combined and arranged in an annular shape is used as a constituent member of a motor.
　次に、本発明を実施例に基づいてさらに詳細に説明する。なお本発明の範囲はこの実施例のみに限定されるものではない。 Next, the present invention will be described in more detail based on examples. The scope of the present invention is not limited to this example.
　（実施例１～６、比較例１～５）
　（ポリイミド前駆体樹脂の作製）
　表１、表２に示す種類と量（ｇ）の芳香族ジアミン（ＯＤＡ、ＢＡＰＰ、ＴＰＥ－Ｑ）を表１、表２に示す量（ｇ）のＮ－メチルピロリドンに溶解させた後、表１、表２に示す種類と量（ｇ）の芳香族テトラカルボン酸二無水物（ＰＭＤＡ）を加えて窒素雰囲気下室温で１時間撹拌した。その後６０℃で２０時間撹拌し反応を終え、室温まで冷却し、密着向上剤としてメラミン（日本サイテックインダストリーズ（株）製、商品名：サイメル３０３）を混合してポリイミド樹脂ワニスを得た。各成分の分子量から計算したイミド基濃度を表１、表２中に記載している。 (Examples 1 to 6, Comparative Examples 1 to 5)
(Preparation of polyimide precursor resin)
After dissolving the types and amounts (g) of aromatic diamines (ODA, BAPP, TPE-Q) shown in Tables 1 and 2 in the amounts (g) of N-methylpyrrolidone shown in Tables 1 and 2, 1. The kind and amount (g) of aromatic tetracarboxylic dianhydride (PMDA) shown in Table 2 were added and stirred at room temperature for 1 hour in a nitrogen atmosphere. Thereafter, the mixture was stirred at 60 ° C. for 20 hours to finish the reaction, cooled to room temperature, and mixed with melamine (made by Nippon Cytec Industries, Inc., trade name: Cymel 303) as an adhesion improver to obtain a polyimide resin varnish. The imide group concentration calculated from the molecular weight of each component is shown in Tables 1 and 2.
　（絶縁電線の作製）
　厚み１．５ｍｍ、幅３．０ｍｍの平角導体の表面に、作製したポリイミド樹脂ワニスを常法によって塗布、焼付けする工程を複数回繰り返して厚み約４０μｍの絶縁層を形成し、実施例１～６、比較例１～５の絶縁電線を作製した。 (Production of insulated wires)
An insulating layer having a thickness of about 40 μm was formed on the surface of a flat conductor having a thickness of 1.5 mm and a width of 3.0 mm by repeating the steps of applying and baking the produced polyimide resin varnish by a conventional method several times. Insulated wires of Comparative Examples 1 to 5 were produced.
　（導体密着力）
　得られた絶縁電線の絶縁層に導体と絶縁層との境界面まで０．５ｍｍ幅の切れ込みを入れ、１８０°剥離試験により導体と絶縁層との密着力を測定した。 (Conductor adhesion)
A 0.5 mm width cut was made in the insulating layer of the obtained insulated wire to the boundary surface between the conductor and the insulating layer, and the adhesion between the conductor and the insulating layer was measured by a 180 ° peel test.
　（層間密着力）
　得られた絶縁電線の絶縁層に、絶縁層の途中まで０．５ｍｍ幅の切れ込みを入れ、１８０°剥離試験により層間密着力を測定した。










(Interlayer adhesion)
The insulation layer of the obtained insulated wire was cut into a 0.5 mm width partway through the insulation layer, and the interlayer adhesion was measured by a 180 ° peel test.










Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　実施例１～３、比較例１～３は、芳香族ジアミンとして分子量の小さいＯＤＡと分子量の大きいＢＡＰＰを併用し、ＢＡＰＰの比率（表中の長鎖ジアミン変性量）を０％～１００％まで変えてイミド基濃度を調整したものである。ＢＡＰＰの比率を高くしてイミド基濃度が低くなるほど層間密着力が高くなっている。また導体密着力はイミド基濃度が低くなるほど低くなっている。イミド基濃度が２８．０％以上３３．０％以下である実施例１～３では導体密着力、層間密着力ともに５０ｇ／ｍｍ以上であり、耐加工性が良好であると推測される。 In Examples 1 to 3 and Comparative Examples 1 to 3, ODA having a low molecular weight and BAPP having a high molecular weight are used in combination as an aromatic diamine, and the ratio of BAPP (modified amount of long-chain diamine in the table) is 0% to 100%. The imide group concentration was adjusted by changing. The higher the BAPP ratio and the lower the imide group concentration, the higher the interlayer adhesion. Further, the conductor adhesion is lower as the imide group concentration is lower. In Examples 1 to 3 in which the imide group concentration is 28.0% or more and 33.0% or less, both the conductor adhesion strength and the interlayer adhesion strength are 50 g / mm or more, and it is estimated that the workability is good.
　実施例４～６、比較例４～５は、芳香族ジアミンとして分子量の小さいＯＤＡと分子量の大きいＴＰＥ－Ｑを併用し、ＴＰＥ－Ｑの比率（表中の長鎖ジアミン変性量）を２５％～１００％まで変えてイミド基濃度を調整したものである。ＴＰＥ－Ｑの比率を高くしてイミド基濃度が低くなるほど層間密着力が高くなっている。また導体密着力はイミド基濃度が低くなるほど低くなっている。イミド基濃度が２８．０％以上３３．０％以下である実施例４～６では導体密着力、層間密着力ともに５０ｇ／ｍｍ以上であり、耐加工性が良好であると推測される。 In Examples 4 to 6 and Comparative Examples 4 to 5, ODA having a low molecular weight and TPE-Q having a high molecular weight are used in combination as an aromatic diamine, and the ratio of TPE-Q (long chain diamine modification amount in the table) is 25%. The concentration of imide groups was adjusted by changing it to ˜100%. The higher the TPE-Q ratio and the lower the imide group concentration, the higher the interlayer adhesion. Further, the conductor adhesion is lower as the imide group concentration is lower. In Examples 4 to 6 in which the imide group concentration is 28.0% or more and 33.0% or less, both the conductor adhesion force and the interlayer adhesion force are 50 g / mm or more, and it is estimated that the workability is good.
　１　第１の絶縁層
　２　第２の絶縁層
　３　導体
　１１絶縁電線
　１２電機コイル
　１３コア
　１４分割ステータ
　１５ステータ DESCRIPTION OF SYMBOLS 1 1st insulating layer 2 2nd insulating layer 3 Conductor 11 Insulated wire 12 Electric coil 13 Core 14 Split stator 15 Stator

Claims (7)

  1. 　芳香族ジアミンと芳香族テトラカルボン酸二無水物とを反応して得られるポリイミド前駆体樹脂を主成分とするポリイミド樹脂ワニスであって、
    前記ポリイミド前駆体樹脂のイミド化後のイミド基濃度が２８．０％以上３３．０％以下である、ポリイミド樹脂ワニス。     A polyimide resin varnish mainly composed of a polyimide precursor resin obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride,
    The polyimide resin varnish whose imide group density | concentration after imidation of the said polyimide precursor resin is 28.0% or more and 33.0% or less.
  2. 　前記芳香族テトラカルボン酸二無水物が、ピロメリット酸二無水物である、請求項１に記載のポリイミド樹脂ワニス。 The polyimide resin varnish according to claim 1, wherein the aromatic tetracarboxylic dianhydride is pyromellitic dianhydride.
  3. 　前記芳香族ジアミンが、２，２－ビス［４－（アミノフェノキシ）フェニル］プロパン（ＢＡＰＰ）、１，３－ビス（４－アミノフェノキシ）ベンゼン、及び１，４－ビス（４－アミノフェノキシ）ベンゼンからなる群から選択される１種以上を含有する、請求項１又は２に記載のポリイミド樹脂ワニス。 The aromatic diamine is 2,2-bis [4- (aminophenoxy) phenyl] propane (BAPP), 1,3-bis (4-aminophenoxy) benzene, and 1,4-bis (4-aminophenoxy). The polyimide resin varnish of Claim 1 or 2 containing 1 or more types selected from the group which consists of benzene.
  4. 　導体及び該導体を直接又は他の層を介して被覆する絶縁層を有する絶縁電線であって、前記絶縁層は、請求項１～３のいずれか１項に記載のポリイミド樹脂ワニスを塗布、焼付けして形成されたものである絶縁電線。 An insulated wire having a conductor and an insulating layer covering the conductor directly or via another layer, wherein the insulating layer is coated with the polyimide resin varnish according to any one of claims 1 to 3, and baked. An insulated wire that is formed as a result.
  5. 　導体及び該導体を直接被覆する絶縁層を有する絶縁電線であって、前記絶縁層は、請求項１～３のいずれか１項に記載のポリイミド樹脂ワニスを塗布、焼付けする工程を複数回繰り返して形成されたものである絶縁電線。 An insulated electric wire having a conductor and an insulating layer that directly covers the conductor, wherein the insulating layer is formed by repeating the step of applying and baking the polyimide resin varnish according to any one of claims 1 to 3 a plurality of times. An insulated wire that is formed.
  6. 　請求項４又は５に記載の絶縁電線を捲線してなる電機コイル。 An electric coil formed by winding the insulated wire according to claim 4 or 5.
  7. 　請求項６に記載の電機コイルを有するモータ。 A motor having the electric coil according to claim 6.
PCT/JP2012/061047 2011-05-09 2012-04-25 Polyimide resin varnish, insulated electric wire using same, electric coil, and motor WO2012153636A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2011103948A JP2012233123A (en) 2011-05-09 2011-05-09 Polyimide resin varnish, insulated electric wire using the same, electric machine coil, and motor
JP2011-103948 2011-05-09

Publications (1)

Publication Number Publication Date
WO2012153636A1 true WO2012153636A1 (en) 2012-11-15

Family

ID=47139121

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/061047 WO2012153636A1 (en) 2011-05-09 2012-04-25 Polyimide resin varnish, insulated electric wire using same, electric coil, and motor

Country Status (2)

Country Link
JP (1) JP2012233123A (en)
WO (1) WO2012153636A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6012672B2 (en) * 2014-07-14 2016-10-25 古河電気工業株式会社 Insulation coated aluminum wire
JP6614953B2 (en) 2015-12-08 2019-12-04 古河電気工業株式会社 Insulated wires, coils and electrical / electronic equipment
CN109054018B (en) * 2018-06-06 2021-05-14 华南理工大学 Polyamide acid solution and preparation method thereof
CN108794748B (en) * 2018-06-06 2021-08-10 华南理工大学 Polyimide film with low dielectric constant and preparation method thereof
EP3950784A4 (en) 2019-03-29 2022-12-21 Essex Furukawa Magnet Wire Japan Co., Ltd. Insulated electrical wire, coil, and electrical/electronic appliance

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63221126A (en) * 1987-03-09 1988-09-14 Kanegafuchi Chem Ind Co Ltd Polyimide resin of excellent water absorption characteristic
JP2001266647A (en) * 2000-03-23 2001-09-28 Unitika Ltd Insulating coating material and insulating paint for obtaining the same
JP2003119380A (en) * 2001-10-05 2003-04-23 Du Pont Toray Co Ltd Flame-retardant molded product, reflector substrate for illuminating equipment and reflector for illuminating equipment
WO2007083526A1 (en) * 2006-01-20 2007-07-26 Kaneka Corporation Polyimide film and use thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63221126A (en) * 1987-03-09 1988-09-14 Kanegafuchi Chem Ind Co Ltd Polyimide resin of excellent water absorption characteristic
JP2001266647A (en) * 2000-03-23 2001-09-28 Unitika Ltd Insulating coating material and insulating paint for obtaining the same
JP2003119380A (en) * 2001-10-05 2003-04-23 Du Pont Toray Co Ltd Flame-retardant molded product, reflector substrate for illuminating equipment and reflector for illuminating equipment
WO2007083526A1 (en) * 2006-01-20 2007-07-26 Kaneka Corporation Polyimide film and use thereof

Also Published As

Publication number Publication date
JP2012233123A (en) 2012-11-29

Similar Documents

Publication Publication Date Title
WO2012102121A1 (en) Polyimide resin varnish, and insulated electrical wire, electrical coil, and motor using same
JP5365899B2 (en) Polyamideimide resin insulating paint and insulated wire using the same
JP5626530B2 (en) Insulating paint, method for producing the same, insulated wire using the same, and method for producing the same
JP2009161683A (en) Polyamideimide resin insulating paint and insulation wire using the same
JP6394697B2 (en) Insulated wires and coils
JP2013253124A (en) Polyimide resin vanish, and insulated electric wire, electric coil and motor using the same
JP2012184416A (en) Polyamideimide resin insulation coating and insulated electric wire formed by using the same
JP2012224697A (en) Polyimide resin varnish, and electric insulated wire, electric appliance coil and motor using the same
WO2012153636A1 (en) Polyimide resin varnish, insulated electric wire using same, electric coil, and motor
JP2013051030A (en) Insulated wire and armature coil using the same, motor
JP2012234625A (en) Insulation wire, electric machine coil using the same, and motor
JP5829696B2 (en) Insulated wire
JP2013033669A (en) Multilayer insulated electric wire, electric coil using the same, and motor
WO2020203193A1 (en) Insulated electrical wire, coil, and electrical/electronic appliance
JP2013101759A (en) Insulation wire, electric machine coil using the same, and motor
JP2017095594A (en) Resin varnish and insulation wire
JP2012046619A (en) Insulated wire, electric appliance coil using the same, and motor
JP5837397B2 (en) Insulated wire and electric coil and motor using the same
JP2013155281A (en) Insulating coating, insulated wire using the insulating coating, and coil using the insulated wire
JP2013028695A (en) Polyimide resin vanish, and insulated electric wire, electric coil and motor using the same
JP5829697B2 (en) Insulated wire
JP2012243614A (en) Insulated wire, and electric coil and motor using the same
JP2015130281A (en) Multilayer insulated wire
JP7107921B2 (en) insulated wire
KR102564595B1 (en) Polyamic Acid Composition and Polyimide Coating Material Comprising The Same

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12782952

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12782952

Country of ref document: EP

Kind code of ref document: A1