JP2011071089A - Electric wire and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric wire in which a conductor and an insulating layer have a high adhesion and which has a higher discharge starting voltage and higher heat resistance than a conventional one. <P>SOLUTION: The electric wire has a conductor, a first insulating layer which is formed on the outer circumference of the conductor and of which 80 wt.% or more of the total is made of a fluororesin, and a second insulating layer which is formed on the outer circumference of the first insulating layer and contains a thermosetting resin. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an electric wire and a manufacturing method thereof.

Electric wires used in automobiles and robots, and coil windings used in motors require high discharge start voltage, heat resistance, etc., and mechanical strength is sufficient to prevent damage during processing. Required.

Under such a background, in Patent Document 1, a small amount of a dispersion of fluororesin fine powder dispersed in alcohol is mixed with an insulating paint such as polyamideimide to form a lubricating paint, and the lubricating paint is baked on the outermost layer. It was proposed to use an insulated wire.

In Patent Document 2, on the insulating film mainly composed of a thermosetting resin, a film composed of a fluororesin not containing a binder or a composition ratio of a binder composed of a fluororesin and a binder in a weight ratio, the fluororesin and the binder There has been proposed an insulated wire characterized in that a film comprising 20% or less of the combined amount is formed.

Patent Document 3 is characterized in that an insulating layer is formed by electrodeposition of a water-dispersed resin emulsion obtained by water-dispersing a polyimide resin, a fluororesin, and a charge imparting agent on a conductor, followed by drying and baking. A method of manufacturing an insulated wire has been proposed.

In Patent Document 4, a self-lubricating insulated wire having a coating made of a lubricating polyamideimide synthesized in the presence of fluororesin fine powder as an outermost layer has been proposed.

JP-A-5-247374 JP 2000-223309 A JP 2002-298664 A JP-A-5-320340

However, in response to demands for miniaturization and higher output of equipment and motors used in automobiles and robots, the density of the current flowing through the wires and coils used there increases, and the winding density also increases. Therefore, an electric wire having high performance that cannot be achieved by a conventional electric wire is required.

The subject of this invention is providing the electric wire which has a higher discharge start voltage and heat resistance than before, while a conductor and an insulating layer have high adhesiveness.

The present invention includes a conductor, a first insulating layer formed on the outer periphery of the conductor, wherein 80% by mass or more of the whole is made of fluororesin, and formed on the outer periphery of the first insulating layer, and includes a thermosetting resin. And a second insulating layer.

The second insulating layer preferably further contains a fluororesin.

The second insulating layer preferably has a mass ratio of the thermosetting resin to the fluororesin of 99.9: 0.1 to 30:70.

The thermosetting resin is at least one selected from the group consisting of polyvinyl formal, polyamideimide, polyimide, polyesterimide, polyester, polyurethane, polyamide, polyethersulfone, polyarylene sulfide, polyetherimide, and polyesterimide. Is preferred.

The fluororesin is polytetrafluoroethylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, ethylene / tetrafluoroethylene copolymer, ethylene / tetrafluoroethylene / hexafluoropropylene. It is preferably at least one selected from the group consisting of a copolymer, polyvinylidene fluoride and polychlorotrifluoroethylene.

The second insulating layer is preferably a layer formed by mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixed solution on the first insulating layer, and baking it.

The present invention is a method for producing the electric wire, wherein a first insulating layer containing 80% or more of a fluororesin is formed on the outer periphery of the conductor, and a thermosetting resin solution is applied on the first insulating layer, It is a manufacturing method characterized by baking and forming a 2nd insulating layer.

The present invention is a method for producing the above-described electric wire, wherein a first insulating layer containing 80% or more of a fluororesin is formed on the outer periphery of a conductor, and a thermosetting resin solution and a fluororesin organosol are mixed. The mixed liquid is applied onto the first insulating layer and baked to form the second insulating layer.

Since the electric wire of the present invention has the above-described configuration, the conductor and the insulating layer are firmly bonded, the dielectric constant is low, and the discharge start voltage is high. In addition, since a thin insulating layer can be formed, heat dissipation is also good. Furthermore, when the outermost layer has a fluororesin, the slipperiness is good and the heat resistance is also excellent.

The electric wire of the present invention is formed on the outer periphery of the conductor, the conductor, 80% by mass or more of the first insulating layer made of fluororesin, and formed on the outer periphery of the first insulating layer. And a second insulating layer. In addition, when saying "the 1st insulating layer formed in the outer periphery of a conductor", this 1st insulating layer will contact | connect a conductor. In the case of “a second insulating layer formed on the outer periphery of the first insulating layer”, the second insulating layer is in contact with the first insulating layer.

The second insulating layer is formed on the outer periphery of the first insulating layer and contains a thermosetting resin. By having the second insulating layer containing the thermosetting resin, the adhesion between the conductor and the first insulating layer is strengthened.

In the electric wire according to the present invention, although 80% by mass or more of the first insulating layer formed on the conductor is made of fluororesin, the adhesion between the conductor and the insulating layer is strong. Usually, fluororesin has a characteristic that it is difficult to adhere to a conductor. Therefore, it is predicted that sufficient adhesive strength cannot be obtained with the configuration of the electric wire of the present invention, but the characteristic configuration of the electric wire of the present invention is high contrary to prediction. It has been found by the present inventors to provide adhesive strength.

In the electric wire of the present invention, the first insulating layer is made of fluororesin at 80% by mass or more. More preferably, it is 85 mass% or more, More preferably, it is 90 mass% or more.

In addition to the fluororesin, the first insulating layer may contain, for example, an inorganic pigment, a filler, an adhesion imparting agent, an antioxidant, a lubricant, a dye, etc., which will be described later.

The second insulating layer is formed on the outer periphery of the first insulating layer and contains a thermosetting resin. It is preferable that 30 mass% or more of the sum total of a thermosetting resin and the other resin contained in a 2nd insulating layer is a thermosetting resin. As other resin, the fluororesin mentioned later is mentioned. The second insulating layer preferably further contains a fluororesin.

In the electric wire of the present invention, the second insulating layer may not contain a fluororesin or may contain a fluororesin. In the case of containing a fluororesin, the mechanical strength and heat resistance are more excellent.

In the electric wire of the present invention, if the thermosetting resin of the second insulating layer is too much, the discharge starting voltage may be lowered or the heat resistance may be inferior. If the amount of the fluororesin is too much, the adhesiveness, mechanical strength, and resistance. There is a risk of poor wear. The mass ratio of the thermosetting resin to the fluororesin is preferably 99.9: 0.1 to 30:70, more preferably 80:20 to 30:70, and 60:40 to 30:70. It is more preferable that it is 70, and it is especially preferable that mass ratio of a thermosetting resin and a fluororesin is 50: 50-30: 70.

In the electric wire, the thermosetting resin is at least one selected from the group consisting of polyvinyl formal, polyamideimide, polyimide, polyesterimide, polyester, polyurethane, polyamide, polyethersulfone, polyarylene sulfide, polyetherimide, and polyesterimide. Preferably it is a seed.

The thermosetting resin is more preferably at least one selected from the group consisting of polyamideimide, polyimide, polyethersulfone, polyarylene sulfide, polyetherimide, and polyesterimide.

You may use the said thermosetting resin individually or in combination of 2 or more types. Preferred embodiments when two or more are used include a combination of polyarylene sulfide and polyamideimide, a combination of polyarylene sulfide and polyimide, a combination of polyarylene sulfide and polyesterimide, and the like.

The polyamideimide [PAI] is a resin composed of a polymer having both an amide bond and an imide bond in the molecular structure. The PAI is not particularly limited. For example, a reaction between an aromatic diamine having an amide group in the molecule and an aromatic tetravalent carboxylic acid such as pyromellitic acid, an aromatic trivalent carboxylic acid such as trimellitic anhydride, Resins comprising a high molecular weight polymer produced by a reaction with a diamine such as 4,4-diaminophenyl ether or a diisocyanate such as diphenylmethane diisocyanate, a reaction between a dibasic acid having an aromatic imide ring in the molecule and a diamine, etc. Is mentioned. As said PAI, what consists of a polymer which has an aromatic ring in a principal chain from the point which is excellent in heat resistance is preferable.

The polyimide [PI] is a resin made of a polymer having an imide bond in the molecular structure. The PI is not particularly limited, and examples thereof include a resin made of a high molecular weight polymer produced by a reaction of an aromatic tetravalent carboxylic anhydride such as pyromellitic anhydride. As said PI, what consists of a polymer which has an aromatic ring in a principal chain from the point which is excellent in heat resistance is preferable.

The polyarylene sulfide [PAS] is a resin made of a polymer having an arylene thioether group in the molecular structure. In the present specification, “arylene” means arylene and does not mean allylene. The PAS is not particularly limited, and examples thereof include polyphenylene sulfide [PPS].

As the PAS, a terminal group represented by a general formula -Ar-Z (wherein Ar represents an arylene group, Z represents a thiolate group (-SM, M represents an alkali metal) or -F). Or a general formula —Ar—Z ′ (wherein Ar represents an arylene group and Z ′ represents a mercapto group (—SH) or —H). It may consist of a polymer having a terminal group.

PPS comprising a polymer having a terminal group represented by the general formula -Ar-Z can be produced by, for example, a method described in U.S. Pat. No. 3,354,129, for example, N-methyl It can be produced by producing a polyarylene thioether by dehalogenation / sulfurization reaction between an alkali metal sulfide such as Na ₂ S or sodium sulfate and a dihaloaromatic compound such as paradichlorobenzene in a polar solvent such as pyrrolidone. it can.

A PPS composed of a polymer having a terminal group represented by the general formula -Ar-Z 'can be produced, for example, by modifying the terminal group represented by the general formula -Ar-Z by acid treatment. it can.

As the polyethersulfone [PES], the following general formula

(In the formula, t represents an integer of 2 or more) and the like. The PES is not particularly limited, and examples thereof include a resin made of a polymer obtained by polycondensation of dichlorodiphenyl sulfone and bisphenol.

The polyesterimide [PEI] is a resin composed of a polymer having both an imide bond and an ester bond in the molecular structure.

More preferably, PAI or PEI is used as the thermosetting resin. By using PAI or PEI, the mechanical strength of the insulating layer can be improved.

In the electric wire, the fluororesin is polytetrafluoroethylene [PTFE], tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer [PFA], tetrafluoroethylene / hexafluoropropylene copolymer [FEP], ethylene / tetrafluoro It is preferably at least one selected from the group consisting of ethylene copolymers, ethylene / tetrafluoroethylene / hexafluoropropylene copolymers, polyvinylidene fluoride, and polychlorotrifluoroethylene. More preferably, the fluororesin is at least one selected from the group consisting of PTFE, PFA and FEP.

As the fluororesin used for the first insulating layer, a melt processable fluororesin is preferable, and FEP or PFA is more preferable.
The fluororesin used for the second insulating layer is preferably at least one selected from the group consisting of PTFE and FEP. PTFE and FEP may be used alone or in combination.

[PTFE]
The PTFE may be a tetrafluoroethylene homopolymer or a modified polytetrafluoroethine [modified PTFE]. The above-mentioned “modified PTFE” means a product obtained by copolymerizing a small amount of a comonomer with TFE so as not to impart melt processability to the obtained copolymer. The small amount of the comonomer is not particularly limited, and examples thereof include HFP, CTFE, 3FH, PAVE, perfluoro (alkoxy vinyl ether), and (perfluoroalkyl) ethylene. One kind or two or more kinds of the small amount of comonomer can be used.

The ratio in which the small amount of the comonomer is added to the modified PTFE varies depending on the type thereof. For example, when PAVE, perfluoro (alkoxy vinyl ether) or the like is used, the TFE and the small amount of the comonomer are usually used. It is preferable that it is 0.001-1 mass% of the total mass with a weight body.

PTFE having a melting point of 320 ° C. or higher is preferable from the viewpoint of heat resistance.

[PFA]
Although it does not specifically limit as said PFA, It is preferable that it is a copolymer which consists of 70-99 mol% of TFE units and 1-30 mol% of PAVE units, 80-97 mol% of TFE units, and 3-20 mols of PAVE units. It is more preferable that the copolymer is composed of%. If the TFE unit is less than 70 mol%, the mechanical properties tend to decrease, and if it exceeds 99 mol%, the melting point becomes too high and the moldability tends to decrease.

The PAVE is selected from the group consisting of perfluoro (methyl vinyl ether) [PMVE], perfluoro (ethyl vinyl ether) [PEVE], perfluoro (propyl vinyl ether) [PPVE], and perfluoro (butyl vinyl ether). It is preferably at least one, more preferably at least one selected from the group consisting of PMVE, PEVE and PPVE, and even more preferably PMVE.

PFA may be a copolymer composed of TFE, PAVE, and a monomer copolymerizable with TFE and PAVE. Examples of the monomer include HFP, CX ¹ X ² = CX ³ (CF _{2 N} X ⁴ (wherein X ¹ , X ² and X ³ are the same or different and each represents a hydrogen atom or a fluorine atom; X ⁴ represents a hydrogen atom, a fluorine atom or a chlorine atom; And a vinyl monomer represented by CF ₂ ═CF—OCH ₂ —Rf ¹ (wherein Rf ¹ represents a perfluoroalkyl group having 1 to 5 carbon atoms). And alkyl perfluorovinyl ether derivatives represented.

As the alkyl perfluorovinyl ether derivative, those in which Rf ¹ is a perfluoroalkyl group having 1 to 3 carbon atoms are preferable, and CF ₂ = CF—OCH ₂ —CF ₂ CF ₃ is more preferable.

PFA has a monomer unit derived from a monomer copolymerizable with TFE and PAVE in an amount of 0.1 to 10 mol%, and a total of TFE unit and PAVE unit is 90 to 99.9 mol%. Is preferred. If the copolymerizable monomer unit is less than 0.1 mol%, the moldability, environmental stress crack resistance and stress crack resistance tend to be inferior, and if it exceeds 10 mol%, heat resistance, mechanical properties and productivity. Tend to be inferior.

[FEP]
Although it does not specifically limit as said FEP, It is preferable that it is a copolymer which consists of 70-99 mol% of TFE units and 1-30 mol% of HFP units, 80-97 mol% of TFE units, and 3-20 mol of HFP units. It is more preferable that the copolymer is composed of%. If the TFE unit is less than 70 mol%, the mechanical properties tend to decrease, and if it exceeds 99 mol%, the melting point becomes too high and the moldability tends to decrease.

FEP may be a copolymer composed of TFE, HFP, and a monomer copolymerizable with TFE and HFP. As the monomer, CF ₂ = CF-ORf ² (wherein Rf ² represents a perfluoroalkyl group having 1 to 5 carbon atoms.) Perfluoro (alkyl vinyl ether) [PAVE], CX ¹ X ² = CX ³ (CF ₂ ) _n X ⁴ (wherein X ¹ , X ² and X ³ are the same or different and represent a hydrogen atom or a fluorine atom, X ⁴ represents a hydrogen atom, a fluorine atom or a chlorine atom, and n represents an integer of 2 to 10. A vinyl monomer and an alkyl perfluorovinyl ether derivative represented by CF ₂ = CF—OCH ₂ —Rf ¹ (wherein Rf ¹ represents a perfluoroalkyl group having 1 to 5 carbon atoms). Named, Even if, it is preferable that the PAVE.

The PAVE is selected from the group consisting of perfluoro (methyl vinyl ether) [PMVE], perfluoro (ethyl vinyl ether) [PEVE], perfluoro (propyl vinyl ether) [PPVE], and perfluoro (butyl vinyl ether). It is preferably at least one, and more preferably at least one selected from the group consisting of PMVE, PEVE and PPVE.

As the alkyl perfluorovinyl ether derivative, those in which Rf ¹ is a perfluoroalkyl group having 1 to 3 carbon atoms are preferable, and CF ₂ = CF—OCH ₂ —CF ₂ CF ₃ is more preferable.

FEP has 0.1 to 10 mol% of monomer units derived from monomers copolymerizable with TFE and HFP, and 90 to 99.9 mol% of TFE units and HFP units in total. Is preferred. If the copolymerizable monomer unit is less than 0.1 mol%, the moldability, environmental stress crack resistance and stress crack resistance tend to be poor, and if it exceeds 10 mol%, heat resistance, mechanical properties, productivity, etc. Tend to be inferior.

Although the said fluororesin should just use 1 or more types, it is also preferable to use 2 or more types of fluororesins. Preferable embodiments when two or more kinds of fluororesins are used include a combination of PTFE and PFA, a combination of PTFE and FEP, and the like.

The fluororesin used for the first insulating layer is preferably a perfluoro resin, and more preferably at least one perfluoro resin selected from the group consisting of PTFE, PFA, and FEP.

When the fluororesin is PTFE, the fluororesin preferably has a standard specific gravity (SSG) of 2.13 to 2.21. When the fluororesin is PFA or FEP, the fluororesin preferably has an MFR at 372 ° C. of 5 to 80 g / 10 min.
In the present specification, the SSG is measured in accordance with ASTM D 4895. The above MFR is compliant with ASTM D3307-01 and flows out from a nozzle with an inner diameter of 2 mm and a length of 8 mm under a 5 kg load at a temperature higher than the melting point by 70 ° C. using a melt indexer (manufactured by Toyo Seiki Co., Ltd.) per 10 minutes. It is the mass (g / 10min) of the polymer to do.

The first insulating layer or the second insulating layer may contain an inorganic pigment in order to improve the discharge starting voltage and the wear resistance. The inorganic pigment is preferably stable even when baked, and examples thereof include titanium, iron oxide, and carbon powder. The inorganic pigment may be contained in any insulating layer constituting the electric wire.

The first insulating layer or the second insulating layer may also contain a filler, an adhesion promoter, an antioxidant, a lubricant, a dye, and the like. The inorganic pigment, filler, adhesion imparting agent, antioxidant, lubricant, dye and the like may be contained in any insulating layer constituting the electric wire.

The thickness of each insulating layer is not limited, but the total thickness of the first insulating layer and the second insulating layer can be 1 to 100 μm. According to the present invention, the total film thickness can be 60 μm or less, or 40 μm or less. Moreover, it can also be thinned to 30 μm or less. Reducing the total film thickness of each insulating layer is advantageous in terms of excellent heat dissipation performance.

The film thickness of the first insulating layer and the second insulating layer may be appropriately set according to the use of the electric wire, etc., for example, the electric wire of the present invention is a conductor, the first insulating layer and the second insulating layer. When it consists of only a layer, it is preferable that a 1st insulating layer is 10-40 micrometers, and a 2nd insulating layer is 5-20 micrometers.

In the electric wire of the present invention, the second insulating layer may be a layer formed by applying and baking a thermosetting resin solution not containing a fluororesin organosol on the first insulating layer, A layer formed by mixing a curable resin solution and a fluororesin organosol and applying the resulting mixed solution on the first insulating layer and baking may be used. It is preferably a layer formed by mixing the resin organosol and applying the obtained mixed solution onto the first insulating layer and baking it. The second insulating layer contains the thermosetting resin and the fluororesin in the above-mentioned mass ratio, the thermosetting resin solution and the fluororesin organosol are mixed, and the obtained mixed solution is applied onto the first insulating layer. However, when the layer is formed by baking, mechanical strength and heat resistance are more excellent. In addition, since the first insulating layer is provided, the discharge starting voltage is high and the heat resistance is further improved.

When an insulating layer is formed from a mixture obtained by mixing a thermosetting resin solution and a fluororesin organosol, the thermosetting resin and the fluororesin are uniformly dispersed in the insulating layer. , Heat resistance and the like are greatly improved.

The thermosetting resin solution and the fluororesin organosol are preferably mixed until the thermosetting resin and the fluororesin are sufficiently mixed with each other, usually by stirring for 5 minutes to 2 hours. .

The liquid mixture may be applied only once or a plurality of times. By applying a plurality of times, pinholes in the insulating film can be reduced.

The baking can be performed by a conventionally known method. You may dry the apply | coated liquid mixture before baking. The baking temperature is preferably 200 to 320 ° C., for example. As for the baking temperature of a 2nd insulating layer, 250 to 300 degreeC is more preferable.

The fluororesin organosol is composed of a fluororesin and an organic medium. Examples of the organic medium include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, cresol, methyl isobutyl ketone and the like.

The thermosetting resin solution is composed of a thermosetting resin and a medium. The medium may be composed of an aqueous medium or may be composed of an organic medium. However, from the viewpoint of uniformly mixing with the fluororesin organosol, the medium may be composed of an organic medium. preferable. Examples of the organic medium include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, cresol, methyl isobutyl ketone and the like.

The concentration of the fluororesin in the organosol may be 1 to 80% by mass or 1 to 50% by mass. The thermosetting resin concentration in the thermosetting resin solution may be 1 to 80% by mass or 1 to 50% by mass. When two or more kinds of fluororesin organosols are used, the above-mentioned “concentration of fluororesin in organosol” is the total concentration of fluororesins with respect to the total mass of the fluororesin organosol. The same applies to the case of the thermosetting resin solution.

The fluororesin organosol preferably has a dispersed particle size of 0.05 to 0.5 μm. When the dispersed particle diameter is too large or too small, there is a risk of causing problems such as cracks.

The fluororesin organosol can be produced by a known method. For example, a method for producing an aqueous dispersion containing colloidal particles of a fluororesin by adding an organic solvent having a boiling point of 100 ° C. or higher and then removing the water by heating (Japanese Patent Publication No. 49-18775, US Patent) No. 2937156 specification, British Patent No. 1094349 specification, Japanese Patent Publication No. 48-17548), a phase inversion agent such as an organic liquid soluble in water or an aqueous electrolyte solution is added to the fluororesin and stirred to add water. For example, a method of inversion into a phase inversion liquid such as an insoluble or hardly soluble organic solvent (see Japanese Examined Patent Publication No. 49-17016) can be used.

The concentration of the solid content (fluororesin and thermosetting resin) in the mixed liquid is preferably 5 to 50% by mass, and more preferably 10 to 30% by mass.

In the liquid mixture for forming the second insulating layer, the mass ratio of the thermosetting resin and the fluororesin in the liquid mixture is 100: 0 to 30. : 70, preferably 99.9: 0.1 to 30:70, more preferably 80:20 to 30:70, and 60:40 to 30:70. Is particularly preferable, and the mass ratio of the thermosetting resin to the fluororesin is more preferably 50:50 to 30:70.

The second insulating layer contains the thermosetting resin and the fluororesin in the above-mentioned mass ratio, the thermosetting resin solution and the fluororesin organosol are mixed, and the obtained mixed solution is applied onto the first insulating layer. However, when the layer is formed by baking, mechanical strength and heat resistance are more excellent. In addition, since the second insulating layer is provided, the discharge start voltage is high and the heat resistance is further improved.

The use of an organosol containing a fluororesin and a thermosetting resin for forming the second insulating layer is beneficial, and it is possible to use other than the layer structure of the electric wire.

The material for forming the conductor is not particularly limited as long as the material has good conductivity, and examples thereof include copper, copper alloy, copper clad aluminum, aluminum, silver, gold, and galvanized iron.

The shape of the conductor is not particularly limited, and may be circular or flat. In the case of a circular conductor, the diameter of the conductor may be 0.3 to 2.5 mm.

As for the electric wire of this invention, it is preferable that the dielectric constant as the whole insulating layer is 3.0 or less. For example, when the electric wire of the present invention is composed of only a conductor, a first insulating layer, and a second insulating layer, the relative dielectric constant when a laminate composed of two layers is measured by the following method is 3.0 or less. It is preferable.

The relative dielectric constant is a value measured by a capacitance method. As a measuring method, a covered electric wire is placed in 1% saline, the electric capacity between the conductor and the outside of the outermost insulating layer is obtained, and the relative dielectric constant is obtained from the thickness and surface area. The measurement can be performed under the following conditions.
Capacitance method dielectric constant measurement method 1 kHz (pF / m)
Inner electrode: Core wire (conductor)
Outside electrode: Water measuring device: NF circuit design block LCZ meter

According to the present invention, the discharge start voltage of the insulating layer can be set to 800 V or more. Moreover, it can also be set to 1000V or more. The discharge start voltage means the discharge start voltage of the entire insulating layer constituting the electric wire. For example, when the electric wire includes a conductor, a first insulating layer, and a second insulating layer, the first insulating layer And the discharge start voltage of the entire insulating layer including the second insulating layer.

The discharge start voltage can be measured for the twist piece at a frequency of 100 kHz and a charge amount of 100 pC using DAC-PD-3 manufactured by Soken Denki Co., Ltd.

The mechanical strength is a value measured by a reciprocating wear tester according to JIS C 3003 10.1.

The manufacturing method of the said electric wire is also one of this invention.

In the electric wire of the present invention, the first insulating layer containing 80% or more of the fluororesin is formed on the outer periphery of the conductor, the thermosetting resin solution is applied on the first insulating layer, and baked to obtain the second insulating layer. It can be suitably manufactured by a manufacturing method characterized by forming a layer.

In the electric wire of the present invention, the first insulating layer containing 80% or more of the fluororesin is formed on the outer periphery of the conductor, the thermosetting resin solution and the fluororesin organosol are mixed, and the obtained mixed solution is used as the first mixture. It can be suitably manufactured by a manufacturing method characterized in that the second insulating layer is formed by applying and baking on the insulating layer.

By forming the second insulating layer from the mixture obtained by mixing the thermosetting resin solution and the fluororesin organosol, the thermosetting resin and the fluororesin are uniformly distributed in the second insulating layer. Since it disperses, an electric wire having a high discharge starting voltage and excellent heat resistance can be obtained. Moreover, since the liquid mixture of the thermosetting resin solution and the fluororesin organosol is excellent in processability, the production method of the present invention is also excellent in productivity.

The mixing of the thermosetting resin solution and the fluororesin organosol, the application of the mixed solution, and the baking are as described above.

The first insulating layer may be formed by applying a paint containing 80% or more of a fluororesin on a conductor and baking it, or by melt extrusion molding. More preferably, it is formed by melt extrusion. The paint containing 80% or more of the fluororesin is applied on the conductor.

When the first insulating layer is formed by applying a paint containing 80% or more of a fluororesin on a conductor and firing it, the firing conditions may be appropriately set depending on the type of the fluororesin used. However, for example, the firing is preferably performed at 270 to 320 ° C.

In the case where the first insulating layer is formed by melt extrusion molding, the melt extrusion molding conditions may be appropriately set depending on the type of fluororesin used and the like, for example, preferably performed at 360 to 400 ° C. .

The electric wire of the present invention may be heated after forming each insulating layer. The heating may be performed at a temperature near the melting point of the fluororesin.

The above electric wires can be suitably used for automobile electric wires, robot electric wires and the like. Moreover, it can be used conveniently also as a coil winding (magnet wire), and if it uses the electric wire of this invention, it will be hard to produce the damage by winding processing. The above winding is suitable for motors, rotating electrical machines, compressors, transformers, etc., requires high voltage, high current and high thermal conductivity, requires high-density winding processing, and is downsized. -It has the characteristics that it can sufficiently withstand the use with high output motors. Moreover, it is suitable also as an electric wire for power distribution, power transmission, or communication.

A substrate, a first insulating layer formed on the substrate and comprising 80% by mass or more of the above-mentioned fluororesin, and a second insulating layer formed on the first insulating layer and containing a thermosetting resin The high-frequency transmission product characterized by having an insulating layer and the substrate are firmly bonded, the dielectric loss is low, and the transmission characteristics are excellent.

The liquid mixture of the thermosetting resin solution and the fluororesin organosol can be suitably used as a material for an insulating layer formed on a high-frequency transmission product such as a printed circuit board.

A substrate, a first insulating layer formed on the substrate and comprising 80% by mass or more of the fluororesin described above, and a thermosetting resin and a fluororesin formed on the first insulating layer. And the second insulating layer has a mass ratio of the thermosetting resin to the fluororesin of 100: 0 to 30:70, and the thermosetting resin solution and the fluororesin organosol. The high-frequency transmission product, which is a layer formed by applying and baking the obtained mixed liquid on the first insulating layer and baking it, firmly bonds the insulating layer and the substrate. The dielectric loss is lower and the transmission characteristics are better.

Next, the present invention will be described with reference to examples, but the present invention is not limited to such examples.

Each numerical value of the examples was measured by the following method.

The thickness of the insulating layer is measured according to JIS C 3003.5.

Discharge start voltage The discharge start voltage was measured at a frequency of 100 kHz and a charge amount of 100 pC using a DAC-PD-3 manufactured by Soken Denki Co., Ltd. for the twist piece.

Abrasion resistance Measured using a reciprocating abrasion tester according to JIS C 3003 10.1.

Example 1

On the conductor, FEP was melt extrusion molded at a die temperature of 380 ° C. and a molding speed of 15 m / min to form a first layer.

In forming the second layer, as the fluororesin organosol, an organosol composed of MIBK and polytetrafluoroethylene [PTFE] (PTFE concentration 70%) and an organosol composed of MIBK and tetrafluoroethylene / hexafluoropropylene copolymer [FEP] (FEP concentration 70%) As a thermosetting resin solution, a 30% PAI solution (HI-680 manufactured by Hitachi Chemical Co., Ltd.) obtained by dissolving polyamideimide [PAI] in an N-methylpyrrolidone solvent was used.

The PTFE organosol, the FEP organosol, and the PAI solution were charged into a rotary stirrer so that the mass ratio (solid content) of the resin components would be PTFE: FEP: PAI = 7: 38: 55. Stir for hours to mix.

100 g of the mixed solution obtained after the stirring was put into a beaker with a rubber stopper composed of a polyethylene beaker with a hole in the bottom and a rubber stopper with a hole fixed in the bottom of the beaker. A copper wire having a diameter of 1.0 mm was passed through the rubber plug into the beaker, and the upper end of the copper wire forming the first layer was passed from the top of the beaker into a continuous firing furnace installed on the top of the beaker.

The continuous firing furnace is obtained by directly connecting three 2 m long firing furnaces vertically. This baking furnace was a hot air circulation type, and the temperature inside the furnace was set to 90 ° C. for the first furnace, 180 ° C. for the second furnace, and 305 ° C. for the third furnace.

By pulling the upper end of the copper wire upward at a speed of 1 m / min, the liquid mixture is applied to the surface of the copper wire in a beaker, and then the copper wire is introduced into a continuous firing furnace and covered with an insulating layer. Obtained wire.

The thickness of the insulating layer (second layer) of the electric wire obtained by the above single operation was 24 μm.
Table 1 shows the evaluation results of the electric wire obtained in Example 1.

The electric wire of the present invention can be suitably used for automobile electric wires, robot electric wires and the like. Further, it can be suitably used as a coil winding (magnet wire).

Claims (8)

Conductors,
A first insulating layer formed on the outer periphery of the conductor and comprising 80% by mass or more of a fluororesin;
A second insulating layer formed on the outer periphery of the first insulating layer and containing a thermosetting resin;
An electric wire characterized by having. The electric wire according to claim 1, wherein the second insulating layer further contains a fluororesin. The electric wire according to claim 2, wherein the second insulating layer has a mass ratio of the thermosetting resin to the fluororesin of 99.9: 0.1 to 30:70. The thermosetting resin is at least one selected from the group consisting of polyvinyl formal, polyamideimide, polyimide, polyesterimide, polyester, polyurethane, polyamide, polyethersulfone, polyarylene sulfide, polyetherimide, and polyesterimide. Item 1. The electric wire according to item 1, 2 or 3. The fluororesin is polytetrafluoroethylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, ethylene / tetrafluoroethylene copolymer, ethylene / tetrafluoroethylene / hexafluoropropylene. The electric wire according to claim 1, 2, 3 or 4, which is at least one selected from the group consisting of a copolymer, polyvinylidene fluoride and polychlorotrifluoroethylene. The second insulating layer is a layer formed by mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixed solution on the first insulating layer, and baking it. The electric wire according to 3, 4 or 5. It is a manufacturing method of the electric wire according to claim 1, 3, 4, or 5,
Forming a first insulating layer containing 80% or more of fluororesin on the outer periphery of the conductor;
A manufacturing method, wherein a thermosetting resin solution is applied onto a first insulating layer and baked to form a second insulating layer. It is a manufacturing method of the electric wire according to claim 2, 3, 4, 5 or 6,
Forming a first insulating layer containing 80% or more of fluororesin on the outer periphery of the conductor;
A manufacturing method comprising mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixed solution on a first insulating layer, and baking the mixture to form a second insulating layer.