WO2011024809A1

WO2011024809A1 - Electric wire and process for production thereof

Info

Publication number: WO2011024809A1
Application number: PCT/JP2010/064281
Authority: WO
Inventors: 吉本洋之; 木下琢哉; 助川勝通; 大谷誠一郎; 平尾隆行; 鳥居寛; 山口安行; 湯川宏和; 三木規彦
Original assignee: ダイキン工業株式会社
Priority date: 2009-08-24
Filing date: 2010-08-24
Publication date: 2011-03-03
Also published as: JP5423800B2; JPWO2011024809A1

Abstract

Disclosed is an electric wire having a higher spark-over voltage, higher mechanical strength typified by abrasion resistance and higher heat resistance than those of conventional electric wires. The electric wire comprises a conducting body and a first insulating layer formed around the conducting body, wherein the first insulating layer comprises a heat-curable resin and a fluororesin, wherein the ratio of the heat-curable resin to the fluororesin is 90:10 to 10:90 by mass. The first insulating layer is produced by mixing a solution of the heat-curable resin with an organosol of the fluororesin, applying the resulting mixed solution onto the conducting body, and baking the conducting body having the mixed solution applied thereon.

Description

Electric wire and manufacturing method thereof

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 starting voltage, mechanical strength, heat resistance, etc. indicated by wear resistance. Mechanical strength is also required to prevent damage.

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.

An object of the present invention is to provide an electric wire having a higher discharge starting voltage, mechanical strength indicated by wear resistance, and heat resistance than before.

The present invention has a conductor and a first insulating layer formed on the outer periphery of the conductor, and the first insulating layer is made of a thermosetting resin and a fluororesin, and the thermosetting resin and the fluororesin Is a layer formed by mixing a thermosetting resin solution and a fluororesin organosol, coating the resulting mixture on a conductor, and baking it. It is the electric wire characterized by this.

It is preferable that the said electric wire has the 2nd insulating layer which is formed in the outer periphery of a 1st insulating layer and 80 mass% or more of the whole consists of a fluororesin.

The electric wire is formed on the outer periphery of the second insulating layer, is made of a thermosetting resin and a fluororesin, and a third insulation having a mass ratio of the thermosetting resin to the fluororesin of 100: 0 to 30:70. The third insulating layer is a layer formed by mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixed solution on the second insulating layer, and baking it. Preferably there is.

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

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

The present invention is a method for manufacturing the above-mentioned electric wire, comprising mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixed solution on a conductor, and baking it to form a first insulating layer. It is also the manufacturing method characterized by these.

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

The present invention is a method for producing the above electric wire, wherein a thermosetting resin solution and a fluororesin organosol are mixed, and the obtained mixed solution is applied onto a conductor and baked to form a first insulating layer, A second insulating layer containing 80% or more of a fluororesin is formed on the outer periphery of the first insulating layer, a thermosetting resin solution and a fluororesin organosol are mixed, and the resulting mixture is used as the second insulating layer. It is also a manufacturing method characterized in that a third insulating layer is formed by applying and baking on the top.

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, the discharge starting voltage is high, and the mechanical strength (abrasion resistance) is excellent. 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 has a conductor and a first insulating layer formed on the outer periphery of the conductor, and the first insulating layer is made of a thermosetting resin and a fluororesin, and is thermosetting. The mass ratio of the resin to the fluororesin is 90:10 to 10:90, and the first insulating layer is obtained by mixing the thermosetting resin solution and the fluororesin organosol and placing the obtained mixture on the conductor. It is a layer formed by applying and baking. 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. In the case of “a third insulating layer formed on the outer periphery of the second insulating layer”, the third insulating layer is in contact with the second insulating layer.

In the electric wire of the present invention, the first insulating layer contains the thermosetting resin and the fluororesin in the above mass ratio, the thermosetting resin solution and the fluororesin organosol are mixed, and the obtained mixed solution is placed on the conductor. Since it is formed by coating and baking, the discharge start voltage is high, and the mechanical strength (wear resistance) and heat resistance are excellent.

In the electric wire of the present invention, if the thermosetting resin of the first insulating layer is too much, the discharge starting voltage may be lowered or the heat resistance may be inferior. . The mass ratio of the thermosetting resin to the fluororesin is preferably 90:10 to 20:80, and more preferably 75:25 to 30:70. In addition, "mass ratio" is solid content mass ratio. In the first insulating layer, the total of the thermosetting resin and the fluororesin is preferably 97 to 100% by mass.

The electric wire of the present invention preferably has a second insulating layer formed on the outer periphery of the first insulating layer. When it has a 2nd insulating layer, it will be excellent in the balance of a discharge start voltage and abrasion resistance.

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

The second insulating layer may contain, for example, an inorganic pigment, a filler, an adhesion imparting agent, an antioxidant, a lubricant, a dye, and the like, which will be described later, in addition to the fluororesin.

The electric wire of the present invention preferably has a third insulating layer formed on the outer periphery of the second insulating layer. The third insulating layer is formed on the outer periphery of the second insulating layer, and is made of a thermosetting resin and a fluororesin, and the mass ratio of the thermosetting resin to the fluororesin is 100: 0 to 30:70. The third insulating layer may be a layer formed by mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixed solution on the second insulating layer, and baking it. A layer formed by applying and baking a thermosetting resin solution not containing a fluororesin organosol on the second insulating layer may be used, but the thermosetting resin solution and the fluororesin organosol are mixed. The obtained liquid mixture is preferably a layer formed by applying and baking on the second insulating layer. In the electric wire of the present invention, the third insulating layer contains the thermosetting resin and the fluororesin in the above-described mass ratio, the thermosetting resin solution and the fluororesin organosol are mixed, and the obtained mixed solution is used as the second mixture. The layer formed by applying and baking on the insulating layer is more excellent in mechanical strength and heat resistance. Moreover, since the electric wire of the present invention has the second insulating layer, the discharge starting voltage is high and the heat resistance is further improved.

In the electric wire of the present invention, if the thermosetting resin of the third insulating layer is too much, the discharge start voltage may be lowered, and if the amount of the fluororesin is too much, the mechanical strength may be inferior. In the third insulating layer, 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. 60:40 to 30:70 is more preferable, and the mass ratio of the thermosetting resin to the fluororesin is particularly preferably 50:50 to 30:70. In the third insulating layer, the total of the thermosetting resin and the fluororesin is preferably 97 to 100% by mass.

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

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 high molecular weight polymers produced by reaction with diamines such as 4,4-diaminophenyl ether and diisocyanates such as diphenylmethane diisocyanate, reaction of dibasic acid having an aromatic imide ring in the molecule and 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].

The PAS includes 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 polymer having the 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 above general formula -Ar-Z can be produced by, for example, the method described in US Pat. No. 3,354,129 and the like, 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 comprising 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.

The fluororesin used for the first 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.
The fluororesin used for the second insulating layer is preferably a melt processable fluororesin, more preferably FEP or PFA.
The fluororesin used for the third 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 “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 polymer. The small amount of the comonomer is not particularly limited. For example, hexafluoropropylene (HFP), chlorotrifluoroethylene (CTFE), trifluoroethylene (3FH), perfluoroalkyl vinyl ether (PAVE), perfluoro (alkoxy) Vinyl ether), (perfluoroalkyl) ethylene and the like. 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 preferably 0.001 to 1% by mass of the total mass with the polymer.

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

[PFA]
The PFA is not particularly limited, but is preferably a copolymer comprising 70 to 99 mol% of TFE units and 1 to 30 mol% of PAVE units, and 80 to 97 mol% of TFE units and 3 to 20 mol 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]
The FEP is not particularly limited, but is preferably a copolymer comprising 70 to 99 mol% of TFE units and 1 to 30 mol% of HFP units, and 80 to 97 mol% of TFE units and 3 to 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 comprising 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 each represents 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.

In FEP, the monomer units derived from monomers copolymerizable with TFE and HFP are 0.1 to 10 mol%, and the total of TFE units and HFP units 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 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 second insulating layer is preferably a perfluoro resin, 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 70 ° C. higher than the melting point, 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, the second insulating layer, or the third insulating layer may contain an inorganic pigment in order to improve the discharge starting voltage and the mechanical strength (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, the second insulating layer, or the third 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, the second insulating layer, and the third 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 thicknesses of the first insulating layer, the second insulating layer, and the third insulating layer may be set as appropriate according to the use of the electric wire, etc. For example, the electric wire of the present invention includes the conductor and the first insulating layer. In the case of consisting only of an insulating layer, the first insulating layer is preferably 10 to 20 μm. In the case of only the conductor, the first insulating layer, and the second insulating layer, the first insulating layer is preferably 5 to 15 μm, and the second insulating layer is preferably 10 to 40 μm. When the electric wire of the present invention comprises only a conductor, a first insulating layer, a second insulating layer, and a third insulating layer, the first insulating layer is 5 to 15 μm, and the second insulating layer is 10 to The thickness is preferably 40 μm, and the third insulating layer is preferably 5 to 20 μm.

In the electric wire of the present invention, the first insulating layer is a layer formed by mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixed solution on a conductor, and baking it.

In the electric wire of the present invention, the third insulating layer is obtained by mixing a thermosetting resin solution and a fluororesin organosol, and applying the obtained mixed liquid (or thermosetting resin solution) on the second insulating layer. , A layer formed by baking.

The coating method is not particularly limited, and a known method such as a dipping method can be used.

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. The discharge start voltage is high, and mechanical strength, heat resistance, and the like are greatly improved.

The mixing of the thermosetting resin solution and the fluororesin organosol is preferably performed until the thermosetting resin and the fluororesin are sufficiently mixed with each other, and can usually be performed 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. The baking temperature of the first insulating layer is more preferably 250 to 270 ° C., and the baking temperature of the third insulating layer is preferably 250 to 310 ° C., more preferably 250 to 300 ° C. Further, from the viewpoint of sufficiently evaporating the medium and the like in the mixed solution and further improving the adhesiveness, the baking temperature of the third insulating layer is preferably higher than the baking temperature of the first insulating layer. For example, the baking temperature of the first insulating layer is 250 to 270 ° C., and the baking temperature of the third insulating layer is preferably higher than 270 ° C. and not higher than 310 ° C., preferably higher than 270 ° C. and lower than 300 ° C. More preferably.

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, and may be 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 30 to 500 nm. More preferably, it is 30 to 350 nm. When the dispersed particle diameter is too large or too small, there is a risk of causing problems such as cracks.
When the fluororesin organosol is an organosol made of a fluororesin excluding PTFE, the dispersed particle diameter is preferably 30 to 200 nm. When the dispersed particle diameter is too large or too small, there is a risk of causing problems such as cracks. More preferably, it is 40 to 100 nm.
When the fluororesin organosol is a PTFE organosol made of PTFE, the dispersed particle size is preferably 150 to 350 nm. When the dispersed particle diameter is too large or too small, there is a risk of causing problems such as cracks. It is more preferably 200 to 300 nm, and further preferably 230 to 260 nm. The dispersed particle diameter is a value measured by a dynamic light scattering method using FPAR-1000 manufactured by Otsuka Electronics Co., Ltd.

The fluororesin organosol can be produced by a known method. For example, a method for producing an aqueous dispersion containing colloidal particles of 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, British Patent No. 1094349, Japanese Patent Publication No. 48-17548), a phase inversion agent such as a water-soluble organic liquid or an aqueous electrolyte solution is added to the fluororesin aqueous dispersion and stirred. And a method of causing phase inversion to a phase inversion liquid such as an organic solvent which is insoluble or hardly soluble in water (see Japanese Patent Publication No. 49-17016).

The concentration of the solid content (fluororesin and thermosetting resin) in the mixed solution is preferably 5 to 70% by mass, more preferably 5 to 50% by mass, and 10 to 30% by mass. More preferably.

In the case of the mixed liquid for forming the first insulating layer, the mass ratio of the thermosetting resin to the fluororesin in the mixed liquid is preferably 90:10 to 10:90, and 90:10 to It is more preferably 20:80, and further preferably 75:25 to 30:70. In the case of the mixed liquid for forming the third insulating layer, the mass ratio of the thermosetting resin to the fluororesin in the mixed liquid is preferably 100: 0 to 30:70, and 99.9: It is more preferably 0.1 to 30:70, still more preferably 80:20 to 30:70, particularly preferably 60:40 to 30:70, and 50:50 to 30:70. Most preferably it is.

The use of the mixed solution for forming the first insulating layer or the third insulating layer is beneficial in obtaining an electric wire having excellent characteristics, and the mixed solution is used for a layer other than the layer structure of the electric wire. It is possible.

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 comprises only a conductor and a first insulating layer, it is preferable that the relative dielectric constant of the first insulating layer measured by the following method is 3.0 or less. When the electric wire of the present invention is composed of only the conductor, the first insulating layer, and the second insulating layer, the relative dielectric constant when the laminate comprising two layers is measured by the following method may be 3.0 or less. preferable. When the electric wire of the present invention is composed of a conductor, a first insulating layer, a second insulating layer, and a third insulating layer, the relative dielectric constant is 3.0 when a laminate composed of three layers is measured by the following method. The following 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)
Outer 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, the electric wire includes a conductor, a first insulating layer, a second insulating layer, and a third insulating layer. , The discharge start voltage of the entire insulating layer including the first insulating layer, the second insulating layer, and the third insulating layer.

The discharge start voltage can be 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 a twist piece prepared in accordance with JIS C3003 11.1.

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.

The electric wire of the present invention is obtained by mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixed solution on a conductor, and baking it to form a first insulating layer. It can manufacture suitably.

The electric wire of the present invention is a mixture of a thermosetting resin solution and a fluororesin organosol, and the resulting mixture is applied onto a conductor and baked to form a first insulating layer. The outer periphery of the first insulating layer In addition, the second insulating layer containing 80% or more of the fluororesin can be preferably formed by a manufacturing method characterized by forming the second insulating layer.

The electric wire of the present invention is a mixture of a thermosetting resin solution and a fluororesin organosol, and the resulting mixture is applied onto a conductor and baked to form a first insulating layer. The outer periphery of the first insulating layer Then, a second insulating layer containing 80% or more of the fluororesin is formed, and the thermosetting resin solution and the fluororesin organosol are mixed, and the obtained mixed liquid (or thermosetting resin solution) is second insulated. It can also be preferably manufactured by a manufacturing method characterized in that the third insulating layer is formed by applying and baking on the layer.

When the first insulating layer is formed from the mixture obtained by mixing the thermosetting resin solution and the fluororesin organosol, the thermosetting resin and the fluororesin are uniformly dispersed in the first insulating layer. Therefore, an electric wire having a high discharge start voltage and excellent mechanical strength, heat resistance, etc. 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 same applies to the third insulating layer.

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

When the second insulating layer is formed by applying a paint containing 80% or more of a fluororesin on the first insulating layer and firing it, the firing conditions are appropriately determined depending on the type of the fluororesin used, etc. For example, the baking is preferably performed at 270 to 320 ° C.

In the case where the second insulating layer is formed by melt extrusion molding, the melt extrusion molding conditions may be appropriately set depending on the type of fluororesin to be used. For example, the extrusion temperature is 360 to 400 ° C. It is preferable.

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. By the heating, the adhesiveness of each insulating layer can be made more excellent.

The above electric wires can be suitably used for automobile electric wires, robot electric wires and the like. Moreover, it can be used suitably also as a coil winding (magnet wire), and if the electric wire of the present invention is used, the electric wire is hardly damaged during winding. 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, It has the characteristics that it can withstand use with high-power motors. Moreover, it is suitable also as an electric wire for power distribution, power transmission, or communication.

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.

The substrate, the first insulating layer formed on the substrate, and the first insulating layer are composed of the thermosetting resin and the fluororesin described above, and the mass ratio of the thermosetting resin and the fluororesin is 90: 10 to 10:90, a high-frequency transmission characterized in that it is a layer formed by mixing a thermosetting resin solution and a fluororesin organosol, coating the resulting mixture on a conductor, and baking it. In the product, the insulating layer and the substrate are firmly bonded, the dielectric loss is low, and the transmission characteristics are excellent.

The high-frequency transmission product may further include a second insulating layer that is formed on the first insulating layer and has 80% by mass or more of a fluororesin. The second insulating layer can be preferably manufactured by forming a second insulating layer containing 80% or more of a fluororesin on the first insulating layer.

The high-frequency transmission product is further formed on the second insulating layer, is made of a thermosetting resin and a fluororesin, and a mass ratio of the thermosetting resin to the fluororesin is 100: 0 to 30:70. Three insulating layers, the third insulating layer is a mixture of a thermosetting resin solution and a fluororesin organosol, and the resulting mixture (or thermosetting resin solution) is mixed on the second insulating layer. It is also a preferred form that it is a layer formed by applying and baking onto a layer.

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 twisted piece prepared in accordance with JIS C3003 11.1 using a DAC-PD-3 manufactured by Soken Denki Co., Ltd. .

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

Example 1
In this example, as fluororesin organosol, organosol (PTFE concentration 70%) composed of methyl isobutyl ketone (MIBK) and polytetrafluoroethylene [PTFE], and MIBK and tetrafluoroethylene / hexafluoropropylene copolymer [FEP] are used. 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 is used. used. The organosol is a dispersion of primary particles.
The FEP organosol of Example 1, which was an organic solvent dispersion by phase inversion of an emulsion-polymerized FEP from an aqueous dispersion to an organic solvent, had a dispersed particle size of 40 to 100 nm and an average particle size of 50 nm. The PTFE organosol has a dispersed particle size of 230 to 260 nm and an average particle size of 255 nm.

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 was passed from the top surface of the beaker into a continuous firing furnace installed at the top of the beaker.

The continuous firing furnace is obtained by directly connecting three 2 m long firing furnaces vertically. This firing 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 270 ° 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 (first layer) of the electric wire obtained by one operation was 24 μm.

On the first layer, FEP was melt-extruded at a die temperature of 380 ° C. and a molding speed of 15 m / min to form a second layer. On top of that, a third layer was formed in the same manner as the first layer.

Example 2
The aqueous dispersion of FEP was placed in a beaker with a rubber stopper consisting of a polyethylene beaker with a hole in the bottom and a rubber stopper with a hole fixed to the bottom of the beaker. The electric wire having the first layer formed in the same manner as in Example 1 is passed through the rubber plug into the beaker, and the upper end of the electric wire is passed from the upper surface of the beaker to the continuous firing furnace installed on the upper portion of the beaker. Thus, the second layer was formed, and then the third layer was formed in the same manner as in Example 1 except that the third furnace was set to 305 ° C., and an electric wire was obtained.

Example 3
The mixed solution of Example 1 was applied and baked three times to obtain an electric wire.

Comparative Example 1
An electric wire was obtained in the same manner as in Example 1 except that only the 30% PAI solution was applied to the conductor to form the first layer.
Table 1 shows the evaluation results of the electric wires obtained in Examples 1 to 3 and Comparative Example 1.

(Heat resistance evaluation)
The heat resistance of the coated wires obtained in Examples 1 to 3 and Comparative Example 1 was evaluated by the following method.
The covered electric wires obtained in Examples 1 to 3 or Comparative Example 1 were heated in an electric furnace at 200 ° C. for 200 hours, removed from the furnace, and returned to room temperature. Then, the test piece was created by the method from two based on JIS C 3003 11.1, and the partial discharge start voltage was measured. The partial discharge start voltage was 80% or more in the ratio before and after the heat treatment in both Example 1, Example 2, and Example 3. In Comparative Example 1, the ratio before and after heat treatment was 40% or less. From this result, it can be seen that the covered electric wires obtained in Examples 1 to 3 have higher heat resistance than the conventional covered electric wires.

Example 4
In this example, the fluorosol organosol was obtained by dissolving MIBK and FEP in an organosol (FEP concentration 70%), and a thermosetting resin solution obtained by dissolving polyamideimide [PAI] in an N-methylpyrrolidone solvent. % PAI solution (HI-680 manufactured by Hitachi Chemical Co., Ltd.) was used. The FEP organosol having the FEP concentration of 70% is the same as the FEP organosol of Example 1.

The FEP organosol and the PAI solution were put into a rotary stirrer so that the mass ratio (solid content) of the resin components was FEP: PAI = 50: 50, and the mixture was stirred for 1 hour and mixed.

The thickness of the insulating layer (first layer) of the electric wire obtained by the above one operation was 10 μm.

On the first layer, FEP was melt-extruded at a die temperature of 380 ° C. and a molding speed of 15 m / min to form a second layer. The film thickness of the second layer was 35 μm. A third layer was formed on the second layer in the same manner as the first layer except that the third furnace was set at 305 ° C. The film thickness of the third layer was 10 μm.

Example 5
In this example, an organic sol composed of MIBK and FEP (70% FEP concentration) was used as the fluororesin organosol, and a polyester imide [PEI] was dissolved in an N-methylpyrrolidone solvent as a thermosetting resin solution. % PEI solution was used. The FEP organosol having the FEP concentration of 70% is the same as the FEP organosol of Example 1.

The FEP organosol and the PEI solution were put into a rotary stirrer so that the mass ratio (solid content) of the resin components was FEP: PEI = 50: 50, and the mixture was stirred for 1 hour and mixed. A first layer was formed in the same manner as in Example 4 except that the mixed liquid obtained after the stirring was used. The film thickness of the first layer was 10 μm. Thereafter, a second layer and a third layer were formed on the first layer by the same method as in Example 4.

Example 6
A first layer, a second layer, and a third layer were formed in the same manner as in Example 4. The thickness of the 1st layer and the 3rd layer was 5 micrometers, respectively.

Example 7
A first layer, a second layer, and a third layer were formed in the same manner as in Example 5. The thickness of the 1st layer and the 3rd layer was 5 micrometers, respectively.

Example 8
A first layer and a second layer were formed in the same manner as in Example 6.

Example 9
A first layer and a second layer were formed by the same method as in Example 7.

Example 10
The aqueous dispersion of FEP was put into a beaker with a rubber stopper, which was 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. An operation in which the electric wire having the first layer formed by the same method as in Example 6 is passed through the rubber plug into the beaker, and the upper end of the electric wire is passed from the upper surface of the beaker to the continuous firing furnace installed on the upper portion of the beaker. The second layer was formed by performing 7 times. Then, the 3rd layer was formed by the same method as Example 6, and the electric wire was obtained. The film thickness of the second layer was 35 μm.

Example 11
The FEP organosol and PEI solution used in Example 7 were put into a rotary stirrer so that the mass ratio (solid content) of the resin components was FEP: PEI = 10: 90, and the mixture was stirred for 1 hour. Mixed. A first layer was formed in the same manner as in Example 7 except that the mixed liquid obtained after the stirring was used. Thereafter, a second layer and a third layer were formed on the first layer by the same method as in Example 7.

Example 12
The FEP organosol and PEI solution used in Example 7 were put into a rotary stirrer so that the mass ratio (solid content) of the resin components was FEP: PEI = 30: 70, and the mixture was stirred for 1 hour. Mixed. A first layer was formed by the same method as in Example 7 except that the mixed liquid obtained after the stirring was used. Thereafter, a second layer and a third layer were formed on the first layer by the same method as in Example 7.

Example 13
The FEP organosol and the PEI solution used in Example 7 were put into a rotary stirrer so that the mass ratio (solid content) of the resin components would be FEP: PEI = 70: 30, and stirred for 1 hour. Mixed. A first layer was formed by the same method as in Example 7 except that the mixed liquid obtained after the stirring was used. Thereafter, a second layer and a third layer were formed on the first layer by the same method as in Example 7.

Example 14
The FEP organosol and PEI solution used in Example 7 were put into a rotary stirrer so that the mass ratio (solid content) of the resin components would be FEP: PEI = 90: 10, and stirred for 1 hour. Mixed. A first layer was formed by the same method as in Example 7 except that the mixed liquid obtained after the stirring was used. Thereafter, a second layer and a third layer were formed on the first layer by the same method as in Example 7.

Example 15
A first layer and a second layer were formed in the same manner as in Example 7. Thereafter, Examples were used except that only a 30% PAI solution (HI-680 manufactured by Hitachi Chemical Co., Ltd.) obtained by dissolving polyamideimide [PAI] in an N-methylpyrrolidone solvent was used on the second layer. A third layer was formed in the same manner as in FIG. The film thickness of the third layer was 5 μm.

Example 16
A first layer and a second layer were formed in the same manner as in Example 7. The FEP organosol and PAI solution used in Example 7 were put into a rotary stirrer so that the mass ratio (solid content) of the resin components was FEP: PAI = 70: 30, and stirred for 1 hour. Mixed. A third layer was formed in the same manner as in Example 7 except that the mixed liquid obtained on the second layer was used.

Example 17
A first layer was formed in the same manner as in Example 7. On the first layer, FEP was melt-extruded at a die temperature of 380 ° C. and a molding speed of 15 m / min to form a second layer. The film thickness of the second layer was 55 μm. A third layer was formed on the second layer by the same method as in Example 7.

Example 18
A first layer was formed in the same manner as in Example 4. The FEP organosol and PAI solution used in Example 4 were charged into a rotary stirrer so that the mass ratio (solid content) of the resin components would be FEP: PAI = 81: 19, and stirred for 1 hour. Mixed. A second layer was formed in the same manner as the first layer except that the mixed solution thus obtained was used. The film thickness of the second layer was 50 μm. A third layer was formed on the second layer by the same method as in Example 4.

Example 19
The FEP organosol and PAI solution used in Example 7 were put into a rotary stirrer so that the mass ratio (solid content) of the resin components was FEP: PEI = 10: 90, and stirred for 1 hour. Mixed. A first layer was formed in the same manner as in Example 7 except that the mixed solution thus obtained was used. A second layer and a third layer were formed on the first layer by the same method as in Example 7.

Comparative Example 2
The first layer was formed in the same manner as in Example 7 except that only the 30% PEI solution was applied to the conductor. The film thickness of the first layer was 8 μm. A second layer was formed on the first layer in the same manner as the first layer except that only the 30% PAI solution was applied. The film thickness of the second layer was 30 μm.

Comparative Example 3
30% PAI obtained by dissolving FEP powder and polyamideimide [PAI] in N-methylpyrrolidone solvent so that the mass ratio (solid content) of the resin component is FEP: PAI = 50: 50 Each solution (HI-680 manufactured by Hitachi Chemical Co., Ltd.) was put into a rotary stirrer and stirred for 1 hour to mix. A first layer was formed in the same manner as in Example 6 except that the obtained mixed solution was used. The film thickness of the first layer was 5 μm. A second layer was formed on the first layer by the same method as in Example 6. A third layer was formed on the second layer by the same method as the first layer.

Comparative Example 4
A first layer was formed in the same manner as in Comparative Example 3. The film thickness of the first layer was 75 μm.
The results of Examples 4 to 19 and Comparative Examples 2 to 4 are shown in Tables 2 to 4.

Comparative Example 5
The FEP aqueous dispersion was converted into secondary particles by coagulation, and then the dried powder was dispersed in MIBK. The dispersion was mixed with the 30% PAI solution (HI-680, manufactured by Hitachi Chemical Co., Ltd.) Created. A coated electric wire was prepared in the same manner as in Example 1 except that this mixed solution was used instead of the mixed solution in Example 1. The powder obtained by making the FEP aqueous dispersion into secondary particles by coagulation and drying has a secondary particle diameter of 0.20 to 0.50 mm, which is about 2000 times that of the FEP organosol used in Example 1. For this reason, when it was made into a paint, because there were FEP secondary particles having a large particle diameter, the film thickness became non-uniform when dipped. Further, since an air layer was present in the particles, the partial discharge start voltage was also as low as 700V.

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

Claims

A conductor and a first insulating layer formed on the outer periphery of the conductor;
The first insulating layer is made of a thermosetting resin and a fluororesin,
The mass ratio of thermosetting resin to fluororesin is 90:10 to 10:90,
An electric wire characterized in that it is a layer formed by mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixture onto a conductor, and baking it.
The electric wire according to claim 1, comprising a second insulating layer formed on the outer periphery of the first insulating layer, wherein 80% by mass or more of the whole is made of a fluororesin.
A third insulating layer formed on the outer periphery of the second insulating layer, made of a thermosetting resin and a fluororesin, and having a mass ratio of the thermosetting resin to the fluororesin of 100: 0 to 30:70; ,
3. The third insulating layer is a layer formed by mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixed solution on the second insulating layer, and baking it. Electric wire.
The thermosetting resin is at least one selected from the group consisting of polyvinyl formal, polyamideimide, polyimide, polyester, polyurethane, polyamide, polyethersulfone, polyarylene sulfide, polyetherimide, and polyesterimide. The electric wire according to 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.
It is a manufacturing method of the electric wire according to claim 1, 2, 3, 4 or 5,
Mix the thermosetting resin solution and fluororesin organosol,
A manufacturing method characterized in that the obtained mixed liquid is applied onto a conductor and baked to form a first insulating layer.
It is a manufacturing method of the electric wire according to claim 2, 3, 4, or 5,
Mix the thermosetting resin solution and fluororesin organosol,
The resulting mixture is applied onto the conductor and baked to form a first insulating layer,
A manufacturing method comprising forming a second insulating layer containing 80% or more of a fluororesin on the outer periphery of the first insulating layer.
It is a manufacturing method of the electric wire according to claim 3, 4 or 5,
Mix the thermosetting resin solution and fluororesin organosol,
The resulting mixture is applied onto the conductor and baked to form a first insulating layer,
Forming a second insulating layer containing 80% or more of a fluororesin on the outer periphery of the first insulating layer;
A manufacturing method comprising mixing a thermosetting resin solution and a fluororesin organosol, applying the obtained mixed solution onto a second insulating layer, and baking the mixture to form a third insulating layer.