CN108431905B - Insulated wire - Google Patents
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- CN108431905B CN108431905B CN201780005958.1A CN201780005958A CN108431905B CN 108431905 B CN108431905 B CN 108431905B CN 201780005958 A CN201780005958 A CN 201780005958A CN 108431905 B CN108431905 B CN 108431905B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/02—Disposition of insulation
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Abstract
An insulated wire comprising a linear conductor and one or more insulating layers laminated on the outer peripheral surface of the conductor, wherein the insulating layers contain silicone.
Description
Technical Field
The present invention relates to an insulated wire. The present invention is claimed to be entitled to the priority of Japanese application No. 2016-.
Background
In an electric device to which a high voltage is applied, for example, a motor used at a high voltage, a high voltage is applied to an insulated wire constituting the electric device, and a partial discharge (corona discharge) is likely to occur on the surface of the insulated coating. When the corona discharge is generated, a local temperature rise, ozone generation, ion generation, or the like occurs in the insulated wire, and insulation breakdown occurs at an early stage. This shortens the life of the insulated wire and hence the electric device. Therefore, an insulated wire used in an electric device having a high application voltage is required to have not only excellent insulation properties, mechanical strength, and the like, but also an improvement in corona discharge start voltage.
As a method for increasing the corona discharge starting voltage, it is effective to reduce the dielectric constant of the insulating film. In order to reduce the dielectric constant of an insulating coating, an insulated wire has been proposed in which a thermosetting film (insulating coating) is formed from an insulating varnish containing a coating film-forming resin and a thermally decomposable resin that decomposes at a temperature lower than the sintering temperature of the coating film-forming resin (see japanese patent application laid-open No. 2012-224714). The insulating wire utilizes the thermal decomposition of the thermal decomposition resin during the sintering of the coating film forming resin, the part becomes a pore, thereby forming a pore in the heating curing film, and the formation of the pore realizes the low dielectric constant of the insulating coating film.
In addition, an overvoltage (surge voltage) may be temporarily applied to the insulated wire during use. When a surge voltage is applied, the insulating layer is deteriorated by heat dissipation, and the product life is shortened. Therefore, an insulated wire containing an inorganic fine particle (silica) in an insulating layer to improve surge resistance has been proposed (see japanese patent application laid-open No. 2007-141507).
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open No. 2012 and 224714
Patent document 2: japanese patent laid-open publication No. 2007-141507
Disclosure of Invention
Means for solving the problems
One embodiment of the present invention, which has been made to solve the above problems, relates to an insulated wire including a linear conductor and one or more insulating layers laminated on an outer peripheral surface of the conductor, wherein the insulating layers contain silicone.
Drawings
Fig. 1 is a schematic cross-sectional view of an insulated electric wire according to an embodiment of the present invention.
Fig. 2 is a schematic cross-sectional view of an insulated electric wire of an embodiment different from that of fig. 1.
Fig. 3 is a schematic cross-sectional view of an insulated wire according to an embodiment different from that of fig. 1 and 2.
Detailed Description
Problems to be solved by the invention
In the conventional insulated wire described above, it is difficult to disperse silica used in the insulating layer in the resin, and the silica is likely to be unevenly distributed, so that the improvement of the surge resistance may be insufficient. In addition, the varnish containing silica has such a disadvantage that: silica precipitates easily, making handling difficult and the manufacturability of the insulated wire lowered.
The present invention has been made in view of the above circumstances, and an object thereof is to provide an insulated wire having excellent surge resistance while maintaining manufacturability.
Effects of the invention
The insulated wire of the present invention has excellent surge resistance while maintaining manufacturability.
Description of embodiments of the invention
An insulated wire according to an embodiment of the present invention includes a linear conductor and one or more insulating layers laminated on an outer peripheral surface of the conductor, wherein the insulating layer contains silicone.
The insulated wire contains silicone in the insulating layer. The silicone is modified into silicon dioxide by heat dissipation when a surge voltage is applied. The organic silicon contained in the insulating layer is difficult to be unevenly distributed in the insulating layer unlike silicon dioxide, and is modified into silicon dioxide after heat dissipation. Therefore, the insulating wire contains the silicone, so that the surge resistance of the insulating layer is uniformly improved while the manufacturability is maintained, and the product life can be remarkably prolonged. The term "silicone" refers to a polymer having a repeating structure of a siloxane bond in which a silicon atom is bonded to an oxygen atom.
At least one of the insulating layers may contain a matrix and a silicone dispersed in the matrix. By containing and dispersing the silicone in the matrix of the insulating layer in this manner, surge resistance can be easily and reliably improved.
At least one of the insulating layers may contain silicone as a main component. By including the layer containing silicone as a main component in the insulating layer, surge resistance can be easily and reliably improved.
At least one of the insulating layers may include a plurality of pores and a shell around the pores, and the shell may include silicone as a main component. When the insulating layer contains such pores and the case, the dielectric constant of the insulating layer can be reduced and the surge resistance can be improved. In addition, since the air holes included in the insulating layer are surrounded by the case, the air holes are difficult to communicate with each other and it is difficult to form coarse air holes. Therefore, the dielectric constant can be reduced while suppressing a reduction in insulation properties and solvent resistance.
The term "main component" refers to a component contained at most, and means, for example, a component containing 50% by mass or more.
[ detailed description of embodiments of the invention ]
Hereinafter, an insulated wire according to an embodiment of the present invention will be described with reference to the drawings.
[ first embodiment ]
The insulated wire 10 of fig. 1 includes a linear conductor 1 and an insulating layer 2 laminated on the outer peripheral surface of the conductor 1. The insulating layer 2 contains a matrix and a silicone 3 dispersed in the matrix.
< conductor >
The conductor 1 is, for example, a round wire having a circular cross section, but may be a rectangular wire having a square cross section or a stranded wire obtained by twisting a plurality of bare wires.
The material of the conductor 1 is preferably a metal having high electrical conductivity and high mechanical strength. Examples of such metals include: copper, copper alloys, aluminum, nickel, silver, soft iron, steel, stainless steel, and the like. The conductor 1 may be formed of a wire of these metals or a multilayer structure in which the wire is further coated with another metal, for example, a nickel-coated copper wire, a silver-coated copper wire, a copper-coated aluminum wire, a copper-coated steel wire, or the like.
As conductors 1The lower limit of the average cross-sectional area is preferably 0.01mm2More preferably 0.1mm2. On the other hand, the upper limit of the average cross-sectional area of the conductor 1 is preferably 10mm2More preferably 5mm2. When the average cross-sectional area of the conductor 1 does not satisfy the lower limit, the volume of the insulating layer 2 relative to the conductor 1 may increase, and the volume efficiency of a coil or the like formed using the insulated wire may decrease. On the other hand, if the average cross-sectional area of the conductor 1 exceeds the upper limit, the insulating layer 2 must be formed thick to sufficiently reduce the dielectric constant, and the diameter of the insulated wire may be unnecessarily increased.
< insulating layer >
As shown in fig. 1, the insulating layer 2 contains a matrix and a silicone 3 dispersed in the matrix.
The lower limit of the average thickness of the insulating layer 2 is preferably 5 μm, and more preferably 10 μm. On the other hand, the upper limit of the average thickness of the insulating layer 2 is preferably 200 μm, and more preferably 100 μm. In the case where the average thickness of the insulating layer 2 does not satisfy the above lower limit, a crack occurs in the insulating layer 2, and the insulation of the conductor 1 may be insufficient. Conversely, when the average thickness of the insulating layer 2 exceeds the above upper limit, the volume efficiency of a coil or the like formed using the insulated wire 10 may be low.
The matrix of the insulating layer 2 is formed of a resin other than silicone 3.
The main component (main polymer) of the matrix is not particularly limited, but when a thermosetting resin is used, for example, the following can be used: polyvinyl formal, thermosetting polyurethane, thermosetting acrylic resin, epoxy resin, phenoxy resin, thermosetting polyester imide, thermosetting polyester amide imide, thermosetting polyamide imide, thermosetting polyimide, and the like. When a thermoplastic resin is used as the main polymer, for example, polyetherimide, polyetheretherketone, polyethersulfone, thermoplastic polyimide, or the like can be used. Among them, thermosetting polyimide is preferable in that the insulating layer forming varnish can be easily applied and the strength and heat resistance of the insulating layer 2 can be easily improved.
The silicone 3 is in the form of particles and is dispersed in the matrix. The silicone 3 may be spherical or flat.
Examples of the silicone include organopolysiloxanes such as polymethylsiloxane.
The lower limit of the average particle size of the silicone 3 is not particularly limited, but is preferably 0.1 μm, more preferably 1 μm, and still more preferably 1.5 μm. On the other hand, the upper limit of the average particle size of the silicone 3 is preferably 10 μm, more preferably 8 μm, and still more preferably 6 μm. When the average particle size of the silicone 3 is smaller than the lower limit, dispersibility may be reduced, and the effect of improving surging resistance may be reduced. On the contrary, when the average particle diameter of the silicone 3 exceeds the upper limit, the dielectric constant of the insulating layer 2 may be increased, the mechanical strength may be lowered, and the insulating layer 2 may be unnecessarily thickened. The "average particle diameter" refers to a particle diameter that indicates the highest volume content ratio in the particle size distribution measured by the laser diffraction particle size distribution measuring apparatus.
The content of the silicone 3 in the insulating layer 2 can be arbitrarily changed depending on an overvoltage (surge voltage) and a lifetime assumed when the insulated wire is used. The lower limit of the content of the silicone 3 in the insulating layer 2 is preferably 5 parts by mass, more preferably 15 parts by mass, and still more preferably 20 parts by mass with respect to 100 parts by mass of the substrate. On the other hand, the upper limit of the content of the silicone 3 in the insulating layer 2 is preferably 60 parts by mass, more preferably 50 parts by mass, and still more preferably 40 parts by mass with respect to 100 parts by mass of the substrate. If the content of the silicone 3 is less than the lower limit, the effect of improving the surge resistance may be insufficient. In contrast, when the content of the silicone 3 exceeds the above upper limit, the dielectric constant of the insulating layer 2 may increase or the mechanical strength or the like may decrease.
The lower limit of the content of the silicone 3 in the insulating layer 2 in the entire insulating layer 2 is preferably 3 mass%, more preferably 10 mass%, and still more preferably 15 mass%. On the other hand, the upper limit of the content of the silicone 3 in the insulating layer 2 in the entire insulating layer 2 is preferably 50 mass%, more preferably 40 mass%, and still more preferably 30 mass%. If the content of the silicone 3 is less than the lower limit, the effect of improving the surge resistance may be insufficient. In contrast, in the case where the content of the silicone 3 exceeds the above upper limit, the mechanical strength and the like of the insulating layer 2 may decrease, and further, the insulating layer 2 may become thick.
The resin composition for forming the insulating layer 2 may contain a curing agent. As the curing agent, there can be exemplified: titanium-based curing agents, isocyanate-based compounds, blocked isocyanates, urea and melamine compounds, amino resins, alicyclic acid anhydrides such as acetylene derivatives and methyltetrahydrophthalic anhydride, fatty acid anhydrides, aromatic acid anhydrides, and the like. These curing agents are appropriately selected depending on the kind of the main polymer contained in the resin composition to be used. For example, in the case of a polyamideimide type, imidazole, triethylamine and the like are preferably used as the curing agent.
Further, examples of the titanium-based curing agent include: tetrapropyl titanate, tetraisopropyl titanate, tetramethyl titanate, tetrabutyl titanate, tetrahexyl titanate, and the like. Examples of the isocyanate compound include: aromatic diisocyanates such as Toluene Diisocyanate (TDI), diphenylmethane isocyanate (MDI), p-phenylene diisocyanate, and naphthalene diisocyanate, aliphatic diisocyanates having 3 to 12 carbon atoms such as Hexamethylene Diisocyanate (HDI), 2, 4-trimethylhexane diisocyanate, and lysine diisocyanate, 1, 4-Cyclohexane Diisocyanate (CDI), isophorone diisocyanate (IPDI), 4 '-dicyclohexylmethane diisocyanate (hydrogenated MDI), methylcyclohexane diisocyanate, isopropylidene dicyclohexyl-4, 4' -diisocyanate, 1, 3-bis (isocyanatomethyl) cyclohexane (hydrogenated XDI), hydrogenated TDI, 2, 5-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, 2, 6-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, and the like, having 5 to 18 carbon atoms Alicyclic isocyanates, aliphatic diisocyanates having an aromatic ring such as Xylylene Diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI), and modified products thereof. As the above-mentioned blocked isocyanate, there may be exemplified: diphenylmethane-4, 4 '-diisocyanate (MDI), diphenylmethane-3, 3' -diisocyanate, diphenylmethane-3, 4 '-diisocyanate, diphenylether-4, 4' -diisocyanate, benzophenone-4, 4 '-diisocyanate, diphenylsulfone-4, 4' -diisocyanate, toluene-2, 4-diisocyanate, toluene-2, 6-diisocyanate, naphthylene-1, 5-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, and the like. As the above melamine compound, there can be exemplified: methylated melamine, butylated melamine, methylolated melamine, butanol modified melamine, and the like. Examples of the acetylene derivative include ethynylaniline and ethynylphthalic anhydride.
< method for manufacturing insulated wire >
Next, a method for manufacturing the insulated wire 10 will be described. The method for manufacturing the insulated wire 10 includes: a step (varnish preparation step) of dispersing the silicone 3 in a resin composition obtained by diluting the resin for forming the insulating layer 2 with a solvent to prepare a varnish for forming an insulating layer; and a step (varnish application step) of applying the varnish for forming an insulating layer to the outer peripheral surface of the conductor 1 and heating the applied varnish.
(varnish preparation Process)
In the varnish preparation step, first, a resin (precursor in the case of a thermosetting resin) forming the matrix of the insulating layer 2 is diluted with a solvent to prepare a resin composition forming the matrix of the insulating layer 2. Next, silicone 3 was dispersed in the resin composition to prepare a varnish for forming an insulating layer. The varnish for forming an insulating layer may be prepared by mixing the silicone 3 with a solvent during dilution of the resin without dispersing the silicone 3 in the resin composition.
As the solvent for dilution, a known organic solvent conventionally used for insulating varnish can be used. Specifically, for example, the polar organic solvents such as N-methyl-2-pyrrolidone, N-dimethylacetamide, N-dimethylformamide, dimethyl sulfoxide, tetramethylurea, hexaethylphosphoric triamide, and γ -butyrolactone include: ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as methyl acetate, ethyl acetate, butyl acetate and diethyl oxalate, ethers such as diethyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol dimethyl ether and tetrahydrofuran, hydrocarbons such as hexane, heptane, benzene, toluene and xylene, halogenated hydrocarbons such as dichloromethane and chlorobenzene, phenols such as cresol and chlorophenol, tertiary amines such as pyridine, and the like, and these organic solvents are used alone or in combination of 2 or more.
The lower limit of the resin solid content concentration of the varnish for forming an insulating layer is preferably 15% by mass, and more preferably 20% by mass. On the other hand, the upper limit of the resin solid content concentration of the varnish for forming an insulating layer is preferably 50% by mass, and more preferably 30% by mass. When the resin solid content concentration of the varnish for forming the insulating layer does not satisfy the lower limit, the thickness that can be formed by one varnish application becomes small, and therefore, the number of repetitions of the varnish application step for forming the insulating layer 2 having a desired thickness becomes large, and the time for the varnish application step may become long. On the other hand, when the resin solid content concentration of the varnish for forming an insulating layer exceeds the upper limit, the varnish may increase in viscosity, and the storage stability of the varnish may deteriorate.
(varnish coating Process)
In the varnish coating step, first, the varnish for forming the insulating layer prepared in the varnish preparation step is applied to the outer peripheral surface of the conductor 1, and then the amount of varnish applied to the conductor 1 and the surface of the varnish after application are adjusted by a coating die.
The coating die has an opening through which the conductor 1 coated with the varnish for forming an insulating layer passes to remove excess varnish, thereby adjusting the amount of varnish applied. This makes the thickness of the insulating layer 2 uniform in the insulated wire 10, and uniform electrical insulation can be obtained.
Next, the conductor 1 coated with the varnish for forming an insulating layer is passed through a sintering furnace to sinter the varnish for forming an insulating layer, thereby forming the insulating layer 2 on the surface of the conductor 1.
The varnish application step and the heating step are repeated until the insulating layer 2 laminated on the surface of the conductor 1 has a predetermined thickness, thereby obtaining the insulated wire 10.
< advantage >
In this insulated wire 10, the silicone 3 dispersed in the matrix of the insulating layer 2 is modified into silica by heat dissipation when a surge voltage is applied. The silicon dioxide can improve surge resistance and suppress deterioration of the insulating layer 2 due to a surge voltage. Therefore, in the insulated wire 10, since the silica derived from the organosilicon 3 is present in the insulating layer 2 after heat dissipation, the surge resistance of the insulating layer 2 can be uniformly improved while maintaining the manufacturability, and the product life can be remarkably improved.
In this insulated wire 10, the insulating layer 2 may have a multilayer structure, and in this case, at least 1 layer of the insulating layer 2 may contain the silicone 3.
[ second embodiment ]
The insulated wire 20 of fig. 2 includes a linear conductor 1 and a plurality of insulating layers 22 laminated on the outer peripheral surface of the conductor 1. The insulating layer 22 has an inner layer 22a and an outer layer 22 b. The conductor 1 is the same as the conductor 1 of the insulated wire 10 of fig. 1, and therefore, the same reference numerals are given thereto and the description thereof is omitted.
< insulating layer >
As shown in fig. 2, the insulating layer 22 includes an inner layer 22a laminated on the outer peripheral surface of the conductor 1, and an outer layer 22b laminated on the outer peripheral surface of the inner layer 22a and forming the outermost layer.
The outer layer 22b contains silicone as a main component. The outer layer 22b may contain other insulating resins and additives in addition to silicone.
The lower limit of the content of the silicone in the outer layer 22b is preferably 2 mass%, and more preferably 5 mass%. On the other hand, the upper limit of the content of the silicone in the outer layer 22b is not particularly limited, and is usually 100 mass%. If the content of the silicone is less than the lower limit, the effect of improving surge resistance may be insufficient.
The lower limit of the average thickness of the outer layer 22b is preferably 1 μm, and more preferably 3 μm. On the other hand, the upper limit of the average thickness of the outer layer 22b is preferably 200 μm, and more preferably 100 μm. If the average thickness of the outer layer 22b does not satisfy the lower limit, the effect of improving the surge resistance may be insufficient. In contrast, in the case where the average thickness of the outer layer 22b exceeds the above upper limit, the dielectric constant of the insulating layer 2 may increase, or the volume efficiency of a coil or the like formed using the insulated wire 20 may become low.
The inner layer 22a is formed of an insulating resin composition. The resin composition may be the same as the resin composition forming the insulating layer 2 of the insulated wire 10 of fig. 1, for example. The resin composition for forming the inner layer 22a may or may not contain silicone.
The lower limit of the average thickness of the inner layer 22a is preferably 5 μm, and more preferably 10 μm. On the other hand, the upper limit of the average thickness of the inner layer 22a is preferably 200 μm, and more preferably 100 μm. In the case where the average thickness of the inner layer 22a does not satisfy the above lower limit, a crack occurs in the inner layer 22a, and the insulation of the conductor 1 may be insufficient. In contrast, in the case where the average thickness of the inner layer 22a exceeds the above upper limit, the volume efficiency of a coil or the like formed using the insulated electric wire 20 may become low.
< method for manufacturing insulated wire >
The insulated wire 20 can be obtained by a manufacturing method including: a step (inner layer varnish coating step) of applying a resin composition obtained by diluting a resin or the like for forming the inner layer 22a with a solvent to the outer peripheral surface of the conductor 1 and heating the resin composition; a step of applying and heating a resin composition obtained by diluting a resin or the like for forming the outer layer 22b with a solvent to the outer peripheral surface of the inner layer 22a (outer layer varnish application step).
< advantage >
In the insulated wire 20, the silicone contained in the inner layer 22a is modified to silica by heat dissipation when a surge voltage is applied. Therefore, in the insulated wire 20, since the silica derived from the silicone exists in the insulating layer 22 after the primary heat dissipation, the surge resistance of the insulating layer 22 can be uniformly improved while maintaining the manufacturability, and the product life can be remarkably improved.
In the insulated wire 20, the insulating layer 2 may have a multilayer structure of 3 or more layers, and the layer containing silicone as a main component is not limited to the outermost layer, and may be the innermost layer or an intermediate layer.
[ third embodiment ]
The insulated wire 30 of fig. 3 includes a linear conductor 1 and an insulating layer 32 laminated on the outer peripheral surface of the conductor 1. The insulating layer 32 contains a plurality of air holes 4 and a housing 5 around the air holes. The conductor 1 is the same as the conductor 1 of the insulated wire 10 of fig. 1, and therefore, the same reference numerals are given thereto and the description thereof is omitted.
< insulating layer >
As shown in fig. 3, the insulating layer 32 contains a plurality of pores 4 derived from hollow particles having a core-shell structure described later and an outer shell 5 mainly composed of silicone.
The insulating layer 32 is formed of a resin composition having insulating properties, air holes 4 dispersed in the resin composition, and a case 5 around the air holes 4. The resin composition may be the same as the resin composition forming the insulating layer 2 of the insulated wire 10 of fig. 1. The resin composition for forming the insulating layer 32 may or may not contain silicone.
As shown in fig. 3, each of the plurality of pores 4 is covered with an outer shell 5, and the outer shell 5 is formed of a shell in which a core of the hollow particles having a core-shell structure is removed and a hollow core is formed. That is, the outer shell 5 is derived from the shell of a hollow particle-forming core-shell structure. In addition, at least a part of the plurality of shells 5 has a defect.
As shown in fig. 3, the plurality of air holes 4 are preferably flat spheres. In addition, when the short axis of the air hole 4 is oriented in the direction perpendicular to the surface of the conductor 1, the air holes are hard to contact each other in the perpendicular direction in which the external force is likely to act, and therefore, it is easier to maintain the independent air holes. Therefore, the larger the proportion of the air holes 4 having the short axis oriented in the direction perpendicular to the surface of the conductor 1 is, the more preferable. The lower limit of the ratio of the number of air holes 4 having the short axis oriented in the direction perpendicular to the surface of the conductor 1 to the number of all the air holes 4 is preferably 60%, and more preferably 80%. When the ratio of the pores 4 having the short axis oriented in the direction perpendicular to the surface of the conductor 1 does not satisfy the lower limit, the pores 4 in which the pores are in contact with each other increase, and the generation of continuous pores may not be sufficiently suppressed.
The lower limit of the average value of the ratio of the length of the short diameter to the length of the long diameter in the cross section including the short diameter and the long diameter of the gas hole 4 is preferably 0.2, and more preferably 0.3. On the other hand, the upper limit of the average value of the above ratios is preferably 0.95, and more preferably 0.9. When the average value of the above ratios does not satisfy the above lower limit, it is necessary to increase the shrinkage amount in the thickness direction at the time of varnish sintering, and therefore, the flexibility of the insulated wire 30 may be reduced. On the contrary, when the average value of the above-mentioned ratios exceeds the above-mentioned upper limit, in the case of increasing the porosity, the pores are likely to contact each other in the thickness direction of the insulating layer 32 on which the external force is likely to act, and the effect of suppressing the communication of the pores 4 may not be sufficiently obtained. The ratio can be adjusted by changing the pressure applied to the hollow particles by shrinkage of the resin composition contained in the varnish for forming the insulating layer during sintering. The pressure applied to the hollow-forming particles may vary depending on, for example, the kind of material to be the main component of the resin composition, the thickness of the insulating layer 32, the material of the hollow-forming particles, the sintering conditions, and the like.
The lower limit of the average value of the major axes of the pores 4 is preferably 0.1 μm, and more preferably 1 μm. On the other hand, the upper limit of the average value of the major axis is preferably 10 μm, and more preferably 8 μm. When the average value of the major axes does not satisfy the lower limit, a desired porosity may not be obtained in the insulating layer 32. On the other hand, if the average value of the major axes exceeds the upper limit, it is difficult to make the distribution of the pores 4 in the insulating layer 32 uniform, and the distribution of the dielectric constant may be likely to be uneven.
At least a part of the plurality of shells 5 existing around the plurality of air holes 4 has a defect. The pores 4 and the shell 5 are derived from hollow particles having a core mainly composed of a thermally decomposable resin and a shell having a thermal decomposition temperature higher than that of the thermally decomposable resin. That is, when the varnish containing the hollow particles is fired, the thermally decomposable resin as the main component of the core is vaporized by thermal decomposition and is scattered through the shell, thereby forming the air holes 4 and the shell 5. At this time, the passage of the thermally decomposable resin in the case exists as a defect in the case 5. The shape of the defect varies depending on the material and shape of the case, but from the viewpoint of enhancing the effect of preventing communication of the air holes 4 of the case 5, cracks, and holes are preferable.
The insulating layer 32 may include a shell 5 having no defect. Depending on the conditions under which the core thermal decomposition resin flows out of the shell, no defect may be formed in the shell 5. The insulating layer 32 may include the air holes 4 not covered with the case 5.
The average thickness of the outer shell 5 is the same as the average thickness of the shell of the hollow-formed particle described later.
The lower limit of the average thickness of the insulating layer 32 is preferably 5 μm, and more preferably 10 μm. On the other hand, the upper limit of the average thickness of the insulating layer 32 is preferably 200 μm, and more preferably 100 μm. In the case where the average thickness of the insulating layer 32 does not satisfy the above lower limit, a crack occurs in the insulating layer 32, and the insulation of the conductor 1 may be insufficient. In contrast, in the case where the average thickness of the insulating layer 32 exceeds the above upper limit, the volume efficiency of the coil or the like formed using the insulated wire 30 may become low.
The lower limit of the porosity of the insulating layer 32 is preferably 5 vol%, and more preferably 10 vol%. On the other hand, the upper limit of the porosity of the insulating layer 32 is preferably 80 vol%, and more preferably 50 vol%. When the porosity of the insulating layer 32 does not satisfy the lower limit, the dielectric constant of the insulating layer 32 is not sufficiently lowered, and the corona discharge start voltage may not be sufficiently increased. In contrast, when the porosity of the insulating layer 32 exceeds the above upper limit, the mechanical strength of the insulating layer 32 may not be maintained. Here, the "porosity" refers to a percentage of the volume of the pores with respect to the volume of the insulating layer including the pores.
The upper limit of the ratio of the dielectric constant of the insulating layer 32 to the dielectric constant of the layer which is made of the same material as that of the insulating layer 32 and does not contain pores is 95%, preferably 90%, and more preferably 80%. When the ratio of the dielectric constants exceeds the upper limit, the corona discharge start voltage may not be sufficiently increased.
< method for manufacturing insulated wire >
Next, a method for manufacturing the insulated wire 30 will be described. The method for manufacturing the insulated wire 30 includes: a step (varnish preparation step) of dispersing hollow-forming particles having a core-shell structure in a resin composition obtained by diluting a resin for forming the insulating layer 32 with a solvent to prepare a varnish for forming an insulating layer; a step (varnish application step) of applying the varnish for forming the insulating layer to the outer peripheral surface of the conductor 1; and a step (heating step) of removing the hollow particle nuclei by heating.
(varnish preparation Process)
In the varnish preparation step, first, the resin forming the insulating layer 32 is diluted with a solvent to prepare a resin composition forming the matrix of the insulating layer 32. Next, the hollow-forming particles were dispersed in the resin composition to prepare a varnish for forming an insulating layer. The varnish for forming an insulating layer may be prepared by mixing hollow particles simultaneously with the dilution of the resin with a solvent, without dispersing the hollow particles in the resin composition.
The hollow particles have a core mainly composed of a thermally decomposable resin and a shell having a thermal decomposition temperature higher than that of the thermally decomposable resin.
As the thermally decomposable resin used as the main component of the core, for example, resin particles thermally decomposed at a temperature lower than the sintering temperature of the resin forming the insulating layer can be used. The sintering temperature of the insulating layer forming resin is appropriately set depending on the kind of the resin, but is usually about 200 ℃ to 600 ℃. Therefore, the lower limit of the thermal decomposition temperature of the thermal decomposition resin used as the core of the hollow particles is preferably 200 ℃ and the upper limit thereof is preferably 400 ℃. Here, the thermal decomposition temperature is a temperature at which the temperature is raised from room temperature at 10 ℃/min under an air atmosphere and the mass reduction rate becomes 50%. The thermal decomposition temperature can be measured, for example, by measuring the thermogravimetric analysis using a thermogravimetric-differential thermal analysis apparatus ("TG/DTA" of SII nanotechnology co.).
The thermal decomposition resin used for the core of the hollow particle is not particularly limited, and examples thereof include: a compound obtained by alkylating one, both or a part of the terminal(s) of polyethylene glycol, polypropylene glycol, or the like, (meth) acrylating or epoxidizing, a polymer of (meth) acrylate having an alkyl group having 1 to 6 carbon atoms such as polymethyl (meth) acrylate, polyethyl (meth) acrylate, polypropyl (meth) acrylate, polybutyl (meth) acrylate, or the like, a polymer of modified (meth) acrylate such as urethane oligomer, urethane polymer, urethane (meth) acrylate, epoxy (meth) acrylate, epsilon-caprolactone (meth) acrylate, or the like, poly (meth) acrylic acid, a crosslinked product thereof, polystyrene, crosslinked polystyrene, or the like. Among them, a polymer of a (meth) acrylate having an alkyl group having 1 to 6 carbon atoms is preferable in that it is easily thermally decomposed at a sintering temperature of the insulating layer forming resin and the pores 4 are easily formed in the insulating layer 2. Examples of the polymer of such a (meth) acrylate include polymethyl methacrylate (PMMA).
The shape of the core is preferably spherical. In order to form the core in a spherical shape, for example, spherical thermally decomposable resin particles may be used as the core. When spherical thermally decomposable resin particles are used, the lower limit of the average particle diameter of the resin particles is not particularly limited, but is preferably 0.1 μm, more preferably 0.5 μm, and still more preferably 1 μm, for example. On the other hand, the upper limit of the average particle diameter of the resin particles is preferably 15 μm, and more preferably 10 μm. When the average particle diameter of the resin particles does not satisfy the lower limit, it may be difficult to produce hollow particles having the resin particles as cores. On the other hand, if the average particle diameter of the resin particles exceeds the upper limit, the hollow particles having the resin particles as cores are too large, and therefore, the distribution of the pores 4 in the insulating layer 32 is difficult to be uniform, and the distribution of the dielectric constant may be likely to be uneven.
As the main component of the shell, silicone is used.
The lower limit of the average thickness of the shell is not particularly limited, but is preferably 0.01 μm, and more preferably 0.02 μm, for example. On the other hand, the upper limit of the average thickness of the shell is preferably 0.5 μm, and more preferably 0.4 μm. When the average thickness of the shell does not satisfy the lower limit, the communication suppressing effect of the air holes 4 may not be sufficiently obtained. In contrast, when the average thickness of the shell exceeds the above upper limit, the volume of the pores 4 becomes too small, and therefore, the porosity of the insulating layer 32 may not be increased to the predetermined level or more. The shell may be formed of 1 layer or a plurality of layers. In the case where the shell is formed of a plurality of layers, the average of the total thickness of the plurality of layers may be within the above-described range.
The upper limit of the CV value (coefficient of variation) of the hollow particles is preferably 30%, and more preferably 20%. When the CV value of the hollow particles exceeds the upper limit, the insulating layer 32 contains a plurality of pores 4 having different sizes, and therefore, the dielectric constant distribution may be likely to vary. The lower limit of the CV value of the hollow particles is not particularly limited, and is preferably 1%, for example. When the CV value of the hollow-forming particles does not satisfy the above lower limit, the cost of the hollow-forming particles may be excessively high.
The hollow-forming particle may have a structure in which the core is formed of 1 thermally decomposable resin particle, or may have a structure in which the core is formed of a plurality of thermally decomposable resin particles and the resin of the shell covers the plurality of thermally decomposable resin particles. The surface of the hollow particles may be smooth without unevenness, or may be formed with unevenness.
In addition, the insulating layer forming varnish may contain a pore forming agent such as thermally decomposable particles for pore formation in addition to the hollow particles. In addition, the varnish for forming an insulating layer may be prepared by combining diluting solvents having different boiling points for pore formation. The pores formed by the pore-forming agent or the pores formed by the combination of the diluent solvents having different boiling points are difficult to communicate with the pores derived from the hollow-forming particles. Therefore, even when the air holes not covered with the case 5 are included, coarse air holes are less likely to be generated in the insulating layer 32 due to the presence of the air holes covered with the case 5.
(varnish coating Process)
In the varnish coating step, the varnish for forming the insulating layer prepared in the varnish preparation step is applied to the outer peripheral surface of the conductor 1, and then the amount of varnish applied to the conductor 1 and the surface of the varnish after application are adjusted by a coating die.
The coating die has an opening through which the conductor 1 coated with the varnish for forming an insulating layer passes, thereby removing excess varnish and adjusting the amount of varnish applied. This makes the thickness of the insulating layer 32 of the insulated wire uniform, and uniform electrical insulation can be obtained.
(heating step)
Next, in the heating step, the conductor 1 coated with the varnish for forming an insulating layer is passed through a sintering furnace to sinter the varnish for forming an insulating layer, thereby forming the insulating layer 32 on the surface of the conductor 1. In the case of firing, the thermally decomposable resin of the core of the hollow particles contained in the varnish for forming an insulating layer is vaporized by thermal decomposition, and the vaporized thermally decomposable resin is scattered by the shell. In this way, the core of the hollow particles is removed by heating at the time of sintering. As a result, hollow particles (shell-only particles) derived from the hollow-forming particles are formed in the insulating layer 32, and the pores 4 are formed in the insulating layer 2 by the hollow particles. Thus, the heating step also serves as a baking step of the varnish for forming the insulating layer.
The varnish coating step and the heating step are repeated until the insulating layer 32 laminated on the surface of the conductor 1 has a predetermined thickness, thereby obtaining the insulated wire 30.
The heating step may be performed before the varnish preparation step. In this case, for example, the hollow particles are heated in a thermostatic bath or the like, and the thermally decomposable resin of the core is vaporized by thermal decomposition, thereby obtaining hollow particles from which the core is removed. In the varnish preparation step, the hollow particles are dispersed in the resin composition forming the matrix of the insulating layer 32 to prepare a varnish for forming an insulating layer. Since the hollow structure of the hollow particles, which are the hollow-forming particles from which the cores have been removed, can be maintained even after the application and sintering of the varnish for forming an insulating layer, the insulating layer 32 including the pores 4 formed by the hollow particles can be formed by the application and sintering of the varnish for forming an insulating layer. However, when the heating step is performed before the varnish preparation step, the step of sintering the varnish for forming the insulating layer is performed after the varnish application step separately from the heating step.
In this way, when the heating step is performed before the varnish preparation step, the nuclei are more easily and reliably eliminated than when the nuclei of the hollow particles are eliminated by heating at the time of sintering. Therefore, pores can be more reliably formed in the insulating layer 32, and foaming of the insulating layer 32 due to the decomposition gas of the thermally decomposable resin can be suppressed.
< advantage >
In this insulated wire 30, the silicone contained in the case 5 is modified into silica by heat dissipation when a surge voltage is applied. Therefore, in the insulated wire 30, since the silica derived from the silicone exists in the insulating layer 32 after the primary heat dissipation, the surge resistance of the insulating layer 32 can be uniformly improved while maintaining the manufacturability, and the product life can be remarkably improved.
In the insulated wire 30, the air holes 4 included in the insulating layer 32 are surrounded by the case 5, and even if the case 5 is in contact with each other, the air holes 4 are difficult to communicate with each other, and therefore, coarse air holes are difficult to be generated. This insulated wire 30 thus suppresses a decrease in insulation and solvent resistance and increases the porosity of the insulating layer 32.
[ other embodiments ]
The presently disclosed embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is not limited to the configuration of the above-described embodiments, but is defined by the claims, and is intended to include meanings equivalent to the claims and all changes within the scope.
The configurations of the above embodiments can be combined as appropriate. For example, in the insulated wire according to the first or second embodiment, at least one layer of the insulating layer may have the bubbles according to the third embodiment.
In the third embodiment, the insulated wire in which one insulating layer is laminated on the outer peripheral surface of the conductor has been described, but a plurality of insulating layers may be laminated on the outer peripheral surface of the conductor. That is, one or more other insulating layers may be stacked between the conductor 1 and the insulating layer 32 including the air holes 4 in fig. 3, one or more other insulating layers may be stacked on the outer peripheral surface of the insulating layer 32 including the air holes 4 in fig. 3, or one or more other insulating layers may be stacked on both the outer peripheral surface and the inner peripheral surface of the insulating layer 32 including the air holes 4 in fig. 3.
In this insulated wire, for example, a primer treatment layer or the like may be provided between the conductor and the insulating layer. The primer treatment layer is a layer provided to improve adhesion between layers, and may be formed of, for example, a known resin composition.
In the case where a primer treatment layer is provided between the conductor and the insulating layer, the resin composition forming the primer treatment layer may contain, for example, one or more resins of polyimide, polyamideimide, polyesterimide, polyester, and phenoxy resin. The resin composition for forming the primer treatment layer may contain an additive such as an adhesion improver. By forming a primer treatment layer between the conductor and the insulating layer using such a resin composition, the adhesion between the conductor and the insulating layer can be improved, and as a result, the properties of the insulated wire, such as flexibility, abrasion resistance, scratch resistance, and processing resistance, can be effectively improved.
The resin composition for forming the primer treatment layer may contain other resins such as epoxy resin, phenoxy resin, melamine resin, and the like, together with the above resin. As each resin contained in the resin composition for forming the primer treatment layer, a commercially available liquid composition (insulating varnish) may be used.
The lower limit of the average thickness of the primer treatment layer is preferably 1 μm, and more preferably 2 μm. On the other hand, the upper limit of the average thickness of the primer treatment layer is preferably 30 μm, and more preferably 20 μm. When the average thickness of the primer treatment layer does not satisfy the lower limit, sufficient adhesion to the conductor may not be exhibited. In contrast, when the average thickness of the primer treatment layer exceeds the above upper limit, the insulated wire may be unnecessarily enlarged in diameter.
Examples
The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
[ examples 1 to 5]
First, copper was cast, drawn, and softened to obtain a conductor having a circular cross section and an average diameter of 1 mm. Varnish containing polyamideimide and the silicone filler (polymethylsilsesquioxane particles; powder of polymethyltrimethoxysilane) shown in table 1 was coated on the outer peripheral surface of the conductor and sintered to coat the insulating layer having an average thickness shown in table 1, thereby obtaining insulated wires of examples 1 to 5. In the insulated wires of examples 4 and 5, the insulating layer had a 2-layer structure of the lower layer and the upper layer, and the silicone filler was contained only in either the lower layer or the upper layer. The filler content in table 1 is the content ratio with respect to 100 parts by mass of polyamideimide.
[ example 6]
Insulated wires were obtained in the same manner as in examples 1 to 3, except that varnish containing hollow particles having a core of PMMA and a shell of silicone and an average particle diameter of 2 μm was used instead of the silicone filler.
Comparative example 1
Insulated wires were obtained in the same manner as in examples 1 to 3, except that the varnish for forming the insulating layer did not contain the silicone filler.
Comparative example 2
Insulated wires were obtained in the same manner as in examples 1 to 3, except that the silica fillers shown in table 1 were used instead of the silicone fillers.
[ evaluation ]
The following evaluations were made for examples 1 to 5 and comparative examples 1 and 2. The results are shown in Table 1.
Stability of varnish
The varnish for forming an insulating layer of examples 1 to 5 and comparative example 2 was stored at 25 ℃ for 30 days, and then the appearance of the varnish was confirmed. A represents that there is no difference in concentration between the solutions in the upper and lower layers of the varnish, and B represents that there is a difference in concentration between the solutions such as precipitation.
< flexibility >
The insulated wires of examples 1 to 5 and comparative examples 1 and 2 were drawn at 0% and wound 30 times along round bars of the same diameter in accordance with the "winding test" defined in 5.1 of JIS-C3216-3(2011) with the sample having no cracks in the insulating layer being designated as a and the sample having cracks being designated as B.
< V-t characteristic (h) >
In the insulated wires of examples 1 to 5 and comparative examples 1 and 2, a sine wave voltage of 10kHz and 1kV was applied to a sample obtained by twisting the same insulated wires in pairs, and the time until short-circuiting (maximum 100 hours) was measured.
[ Table 1]
According to table 1, examples 1 to 6 having an insulating layer containing silicone had the same BDV as comparative example 1 having no silicone in the insulating layer, but had excellent V-t characteristics. In comparative example 2 in which silica was contained in the insulating layer, the V-t characteristic was high, but precipitation occurred in the varnish, and the treatment was difficult, and the flexibility of the obtained insulated wire was insufficient. From these results, it is found that by containing silicone in the insulating layer, the surge resistance of the insulating layer can be uniformly improved while maintaining the manufacturability, and the product life can be remarkably improved.
[ confirmation test for modification into silica ]
The white powder precipitated in the insulating layer of the insulated wire of example 2 after the V-t characteristic test (test piece 1) and the insulating layer of the insulated wire of example 2 before the test (test piece 2) were subjected to XPS analysis using "quantera sxm" manufactured by ULVAC PHI corporation. The results (atomic concentrations) are shown in table 2.
[ Table 2]
| C | N | O | Na | | |
| Test piece | |||||
| 1 | 12.2 | 1.0 | 61.8 | 0 | 25.0 |
| |
79.3 | 1.9 | 15.4 | 0.6 | 2.8 |
As shown in table 2, in the insulated wire (test piece 1) in which a short circuit occurred, a large amount of silicon dioxide (SiO) was detected as compared with the insulating layer (test piece 2) before the test2) It was confirmed that the organosilicon was modified to silica.
Description of the symbols
1 conductor
2. 22, 32 insulating layer
3 organosilicon
4 air holes
5 outer cover
10. 20, 30 insulated wire
22a inner layer
22b outer layer
Claims (11)
1. An insulated wire comprising a linear conductor and one or more insulating layers laminated on the outer peripheral surface of the conductor,
the insulating layer contains an organic silicon,
the silicone is a polymer having a repeating structure of a siloxane bond in which a silicon atom is bonded to an oxygen atom,
the thickness of the insulating layer is 5 μm to 200 μm,
the main component of the insulating layer is a thermosetting resin.
2. The insulated wire according to claim 1,
at least one of the insulating layers contains a matrix and a silicone dispersed in the matrix.
3. The insulated wire according to claim 1,
at least one layer of the insulating layer contains organic silicon as a main component.
4. The insulated wire according to claim 1,
at least one layer of the insulating layer includes a plurality of pores and a shell around the pores, and the shell contains silicone as a main component.
5. The insulated wire according to claim 4,
the porosity of the insulating layer is 5 vol% or more and 80 vol% or less.
6. The insulated wire according to claim 4,
the air holes are flat spheres.
7. The insulated wire according to claim 5,
the air holes are flat spheres.
8. The insulated wire according to claim 6,
the minor axes of the plurality of air holes are oriented in a direction perpendicular to the surface of the conductor.
9. The insulated wire according to claim 7,
the minor axes of the plurality of air holes are oriented in a direction perpendicular to the surface of the conductor.
10. The insulated wire according to claim 2,
the average particle diameter of the organic silicon is more than 0.1 μm and less than 10 μm.
11. The insulated wire according to any one of claims 1 to 10,
there is further a primer treatment layer between the conductor and the insulating layer.
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|---|---|---|---|
| JP2016-024006 | 2016-02-10 | ||
| JP2016024006A JP6613163B2 (en) | 2016-02-10 | 2016-02-10 | Insulated wire |
| PCT/JP2017/000614 WO2017138284A1 (en) | 2016-02-10 | 2017-01-11 | Insulated wire |
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| CN108431905A CN108431905A (en) | 2018-08-21 |
| CN108431905B true CN108431905B (en) | 2020-05-05 |
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| JP (1) | JP6613163B2 (en) |
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| WO (1) | WO2017138284A1 (en) |
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| WO2018186259A1 (en) * | 2017-04-03 | 2018-10-11 | 住友電気工業株式会社 | Insulated electric wire |
| EP3780015A4 (en) | 2018-03-30 | 2021-12-22 | Essex Furukawa Magnet Wire Japan Co., Ltd. | Insulated electric wire |
| CN110136895B (en) * | 2019-05-09 | 2020-12-11 | 无锡锡洲电磁线有限公司 | PEEK enameled wire processing technology |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1220040A (en) * | 1996-05-29 | 1999-06-16 | Abb阿西亚布朗·勃法瑞公司 | Insulated conductor for high voltage winding |
| CN103680744A (en) * | 2012-09-25 | 2014-03-26 | 尼克桑斯公司 | Silicone multilayer insulation for electric cable |
| CN103971797A (en) * | 2013-02-01 | 2014-08-06 | Ls电线有限公司 | Insulating wire having excellent partial discharge resistance and high partial discharge inception voltage |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49781B1 (en) * | 1969-06-19 | 1974-01-09 | ||
| JPS4913308B1 (en) * | 1970-09-15 | 1974-03-30 | ||
| JPS512627B1 (en) * | 1970-12-28 | 1976-01-27 | ||
| JPS5818723B2 (en) * | 1972-04-19 | 1983-04-14 | 住友電気工業株式会社 | Hakuriseisetsuendensen |
| JP2789645B2 (en) * | 1989-02-27 | 1998-08-20 | 住友電気工業株式会社 | Insulated wire and its manufacturing method |
| JPH0794025A (en) * | 1993-09-21 | 1995-04-07 | Furukawa Electric Co Ltd:The | Robust enamel-insulated electric wire |
| JP2003007144A (en) * | 2001-06-22 | 2003-01-10 | Mitsubishi Cable Ind Ltd | Flat cable |
| DE102011083228A1 (en) * | 2011-09-22 | 2013-03-28 | Siemens Aktiengesellschaft | Insulating systems with improved partial discharge resistance, process for the preparation thereof |
| JP5700004B2 (en) * | 2012-09-04 | 2015-04-15 | 日立金属株式会社 | Insulated wire and coil using the same |
| JP2014133834A (en) * | 2013-01-11 | 2014-07-24 | Auto Network Gijutsu Kenkyusho:Kk | Resin composition for wire coating, insulated wire and wire harness |
| CN204834136U (en) * | 2014-11-21 | 2015-12-02 | 3M创新有限公司 | Electric power cable |
| WO2017073551A1 (en) * | 2015-10-28 | 2017-05-04 | 住友電気工業株式会社 | Insulating electric wire and varnish for forming insulating layers |
-
2016
- 2016-02-10 JP JP2016024006A patent/JP6613163B2/en active Active
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- 2017-01-11 WO PCT/JP2017/000614 patent/WO2017138284A1/en active Application Filing
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1220040A (en) * | 1996-05-29 | 1999-06-16 | Abb阿西亚布朗·勃法瑞公司 | Insulated conductor for high voltage winding |
| CN103680744A (en) * | 2012-09-25 | 2014-03-26 | 尼克桑斯公司 | Silicone multilayer insulation for electric cable |
| CN103971797A (en) * | 2013-02-01 | 2014-08-06 | Ls电线有限公司 | Insulating wire having excellent partial discharge resistance and high partial discharge inception voltage |
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| CN108431905A (en) | 2018-08-21 |
| JP2017142998A (en) | 2017-08-17 |
| JP6613163B2 (en) | 2019-11-27 |
| WO2017138284A1 (en) | 2017-08-17 |
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