JP2018029004A - Self-lubricating insulated wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-lubricating insulated wire having excellent surface lubricity.SOLUTION: A self-lubricating insulated wire according to one embodiment has a linear metal conductor, and one or more insulating layers stacked around the metal conductor. The outermost layer of one or more insulating layers has a matrix predominantly composed of synthetic resin, and a plurality of particles dispersed in the matrix and predominantly composed of fluorine resin. The content of the particles in the outermost layer is 0.5 mass% or more and 10 mass% or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a self-lubricating insulated wire.

  A coil formed by winding an insulated wire is used for components such as general household electric appliances and automobiles such as a motor, an alternator, and an ignition. The insulated wire forming such a coil is generally composed of a conductive metal conductor and a resin insulating layer covering the conductive conductor.

  When producing a coil with the above insulated wire, the insulated wire is wound at high speed and high density using a high-speed automatic winding machine, etc., but the insulation layer on the surface of the insulated wire is damaged by this winding. Insulation characteristics may be degraded. Therefore, in order to suppress the damage of the insulating layer and the deterioration of the insulation characteristics due to the winding as described above, an insulated wire having a small frictional force and high surface lubricity is required.

  On the other hand, an insulated wire whose surface lubricity is improved by applying a lubricant to the surface of the insulating layer has been developed (see International Publication No. 2009/069545).

International Publication No. 2009/069545

  However, there is a limit to the improvement of surface lubricity by a lubricant such as the conventional insulated wire. In addition, when a lubricant is used, it is necessary to precisely control the amount of the lubricant applied, and it is difficult to uniformly apply the entire surface of the electric wire film.

  This invention is made | formed based on the above situations, and it aims at providing the self-lubricating insulated wire excellent in surface lubricity.

  A self-lubricating insulated wire according to an aspect of the present invention made to solve the above-described problem includes a linear metal conductor and one or more insulating layers laminated on the outer periphery of the metal conductor, The outermost layer of one or more insulating layers has a matrix mainly composed of a synthetic resin and a plurality of particles dispersed in the matrix and mainly composed of a fluororesin, and the inclusion of particles in the outermost layer. The rate is 0.5 mass% or more and 10 mass% or less.

  The self-lubricating insulated wire is excellent in surface lubricity.

FIG. 1 is a schematic cross-sectional view of a self-lubricating insulated wire according to an embodiment of the present invention. FIG. 2 is a schematic side view illustrating a method for measuring the dynamic friction coefficient of the self-lubricating insulated wire. FIG. 3 is a schematic plan view of the measurement method of FIG.

[Description of Embodiment of the Present Invention]
A self-lubricating insulated wire according to an aspect of the present invention includes a linear metal conductor and one or more insulating layers stacked on the outer periphery of the metal conductor, and the outermost layer of the one or more insulating layers. Has a matrix mainly composed of a synthetic resin and a plurality of particles dispersed in the matrix and mainly composed of a fluororesin, and the content of the particles in the outermost layer is 0.5% by mass or more and 10% by mass. It is below mass%.

  The self-lubricating insulated wire has excellent surface lubricity because the outermost layer of the insulating layer has a plurality of particles mainly composed of a fluororesin, and these particles reduce friction.

  The average particle size of the particles is preferably 0.01 μm or more and 5 μm or less. Thus, when the average particle diameter of the particles is within the above range, the insulating layer can be easily formed and relatively large lubricity (reduction of frictional force) can be obtained.

  The main component of the matrix is preferably polyimide, polyamideimide or polyesterimide. Thus, when the main component of the matrix is the resin, the heat resistance, workability, and insulation of the insulating layer are improved.

  The coefficient of dynamic friction of the self-lubricating insulated wire is preferably 0.8 or less. Thus, when the dynamic friction coefficient of the self-lubricating insulated wire is equal to or less than the above upper limit, it is possible to more reliably prevent the insulation layer from being damaged due to the friction during the winding process.

  The average thickness of the outermost layer is preferably 1 μm or more and 50 μm or less. Thus, when the average thickness of the outermost layer is within the above range, the outermost layer has sufficient strength and insulating properties while being relatively easy to mold.

  The main component of the particles may be polytetrafluoroethylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, or tetrafluoroethylene / ethylene copolymer. Thus, the main component of the particles is polytetrafluoroethylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer or tetrafluoroethylene / ethylene copolymer. Further, lubricity and insulation are further improved.

  The “main component” is a component having the highest content, preferably 50% by mass or more, more preferably 80% by mass or more. The “average particle diameter” is an average of a major axis (maximum diameter) measured by microscopic observation and a minor axis perpendicular to the major axis, and means an average of measured values of 10 or more particles. Further, the “dynamic friction coefficient” means a friction coefficient in the case where the self-lubricating insulated wires are vertically crossed and one of them is slid in the other length direction.

[Details of the embodiment of the present invention]
Hereinafter, a self-lubricating insulated wire according to an embodiment of the present invention will be described with reference to the drawings.

[Self-lubricating insulated wire]
The self-lubricating insulated wire of FIG. 1 includes a linear metal conductor 1 and two insulating layers (an inner layer 2 and an outermost layer 3) laminated on the outer periphery of the metal conductor 1.

<Metal conductor>
The metal conductor 1 is, for example, a round wire having a circular cross section, but may be a square wire having a square cross section or a stranded wire obtained by twisting a plurality of strands.

  The material of the metal conductor 1 is preferably a metal having high conductivity and high mechanical strength. Examples of such metals include copper, copper alloys, aluminum, nickel, silver, iron, steel, and stainless steel. The metal conductor 1 is a material in which these metals are formed in a linear shape, or a multilayer structure in which such a linear material is further coated with another metal, such as a nickel-coated copper wire, a silver-coated copper wire, a copper-coated wire. Aluminum wires, copper-coated steel wires, etc. can be used.

The lower limit of the average cross-sectional area of the metal conductor 1 is preferably 0.01 mm ^2, 0.1 mm ² is more preferable. On the other hand, the upper limit of the average cross-sectional area of the metal conductor 1 is preferably 25 mm ^2, 15 mm ² is more preferable. When the average cross-sectional area of the metal conductor 1 is less than the lower limit, the cross-sectional area of the insulating layer with respect to the metal conductor 1 is increased, and the volume efficiency of a coil or the like formed using the self-lubricating insulated wire may be reduced. is there. On the contrary, when the average cross-sectional area of the metal conductor 1 exceeds the upper limit, the flexibility of the self-lubricating insulated wire may be insufficient.

<Inner layer>
The inner layer 2 is laminated on the outer peripheral surface of the metal conductor 1 and is located inside the outermost layer 3. The inner layer 2 is composed of a resin composition.

  The resin as the main component of the resin composition forming the inner layer 2 is not particularly limited, but examples thereof include polyethersulfone, polyetherimide, polycarbonate, polyphenylsulfone, polysulfone, polyethylene terephthalate, and polyetheretherketone. Thermoplastic resins and heat such as polyvinyl formal, thermosetting polyurethane, thermosetting acrylic, epoxy, thermosetting polyester, thermosetting polyester imide, thermosetting polyester amide imide, aromatic polyamide, thermosetting polyamide imide, thermosetting polyimide A curable resin can be used. Among these thermosetting resins, polyimide (PI), polyamide imide (PAI), or polyester imide (PEI), which has a low dielectric constant and can make the dielectric constant of the inner layer 2 relatively small, and is excellent in insulation and strength, are particularly. preferable.

  Moreover, you may make the resin composition which forms the inner layer 2 contain a hardening | curing agent with the said resin. Curing agents include titanium-based curing agents, isocyanate compounds, blocked isocyanates, urea and melamine compounds, amino resins, alicyclic acid anhydrides such as methyltetrahydrophthalic anhydride, aliphatic acid anhydrides, and aromatic acid anhydrides. Etc. are exemplified. These curing agents are appropriately selected according to the type of resin contained in the inner layer 2. For example, in the case of polyamideimide, imidazole, triethylamine and the like are preferably used as the curing agent.

  Examples of the titanium-based curing agent include tetrapropyl titanate, tetraisopropyl titanate, tetramethyl titanate, tetrabutyl titanate, and tetrahexyl titanate. Examples of the isocyanate compound include aromatic diisocyanates such as tolylene diisocyanate (TDI), diphenylmethane isocyanate (MDI), p-phenylene diisocyanate, and naphthalene diisocyanate, hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexane diisocyanate, C3-C12 aliphatic diisocyanate such as lysine diisocyanate, 1,4-cyclohexane diisocyanate (CDI), isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), methylcyclohexane diisocyanate, isopropylidene Dicyclohexyl-4,4′-diisocyanate, 1,3-diisocyanatomethylcyclohexane (hydrogenated XD ), Hydrogenated TDI, carbon such as 2,5-bis (isocyanatomethyl) -bicyclo [2,2,1] heptane, 2,6-bis (isocyanatomethyl) -bicyclo [2,2,1] heptane Examples thereof include aliphatic diisocyanates having an aromatic ring such as alicyclic isocyanate, xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI), and modified products thereof. Examples of the blocked isocyanate include diphenylmethane-4,4′-diisocyanate (MDI), diphenylmethane-3,3′-diisocyanate, diphenylmethane-3,4′-diisocyanate, diphenylether-4,4′-diisocyanate, and benzophenone-4,4. '-Diisocyanate, diphenylsulfone-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, naphthylene-1,5-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, etc. Is exemplified. Examples of the melamine compound include methylated melamine, butylated melamine, methylolated melamine, and butyrololized melamine.

  The resin in the resin composition forming the inner layer 2 may be cross-linked. By cross-linking the resin in the resin composition forming the inner layer 2, the mechanical strength of the inner layer 2 is improved, and the mechanical strength of the inner layer 2 is easily maintained. Moreover, chemical resistance and weld resistance can also be improved by crosslinking the resin in the resin composition forming the inner layer 2.

  Moreover, as a minimum of the average thickness of the inner layer 2, 5 micrometers is preferable and 10 micrometers is more preferable. On the other hand, the upper limit of the average thickness of the inner layer 2 is preferably 200 μm, and more preferably 180 μm. When the average thickness of the inner layer 2 is less than the above lower limit, the insulating property of the inner layer 2 may not be sufficiently improved. Conversely, when the average thickness of the inner layer 2 exceeds the upper limit, the self-lubricating insulated wire may unnecessarily increase in diameter.

<Outermost layer>
The outermost layer 3 includes a matrix 4 mainly composed of a synthetic resin and a plurality of particles 5 dispersed in the matrix and mainly composed of a fluororesin.

  The lower limit of the average thickness of the outermost layer 3 is preferably 1 μm, more preferably 2 μm, and even more preferably 3 μm. On the other hand, the upper limit of the average thickness of the outermost layer 3 is preferably 50 μm, and more preferably 40 μm. When the average thickness of the outermost layer 3 is less than the lower limit, the mechanical strength of the outermost layer 3 may be insufficient. On the contrary, when the average thickness of the outermost layer 3 exceeds the above upper limit, the flexibility of the self-lubricating insulated wire may be insufficient.

  The lower limit of the ratio of the average thickness of the outermost layer 3 to the average thickness of the inner layer 2 is preferably 5%, more preferably 10%, and even more preferably 20%. On the other hand, the upper limit of the ratio is preferably 700%, more preferably 650%, and still more preferably 600%. When the said ratio is less than the said minimum, there exists a possibility that the insulation strength of the said self-lubricating insulated wire may become inadequate. On the contrary, when the ratio exceeds the upper limit, the mechanical strength of the outermost layer 3 may be insufficient.

(matrix)
The synthetic resin as the main component of the matrix 4 of the outermost layer 3 is not particularly limited, but examples thereof include polyethersulfone, polyetherimide, polycarbonate, polyphenylsulfone, polysulfone, polyethylene terephthalate, and polyetheretherketone. Thermoplastic resins such as polyvinyl formal, thermosetting polyurethane, thermosetting acrylic, epoxy, thermosetting polyester, thermosetting polyester imide, thermosetting polyester amide imide, aromatic polyamide, thermosetting polyamide imide, thermosetting polyimide, etc. A thermosetting resin can be used. In addition, a thermoplastic resin is more preferable as a resin for forming the outermost layer 3 than a thermosetting resin because the flexibility of the outermost layer 3 is easily maintained. Among these resins, polyimide (PI), polyamideimide (PAI), or polyesterimide (PEI), which is excellent in insulation, heat resistance, and processability, is particularly preferable.

  Moreover, you may make the matrix 4 which forms the outermost layer 3 contain a hardening | curing agent with the said resin. The curing agent can be the same as the curing agent contained in the inner layer 2 described above.

  Further, the resin in the matrix 4 that forms the outermost layer 3 may be cross-linked. By cross-linking the resin in the matrix 4 forming the outermost layer 3, the mechanical strength of the outermost layer 3 is improved, and the decrease in mechanical strength due to the inclusion of the particles 5 can be compensated. Moreover, chemical resistance and weld resistance can also be improved by crosslinking the resin in the matrix 4 forming the outermost layer 3.

(particle)
The particles 5 of the outermost layer 3 are exposed on the surface of the outermost layer 3 to express the low friction property of the fluororesin, and reduce the frictional force by forming fine irregularities on the outer peripheral surface of the outermost layer 3.

  Examples of the fluororesin that is the main component of the particles 5 include polytetrafluoroethylene (PTFE), polytetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), and tetrafluoroethylene / hexafluoropropylene copolymer ( FEP), tetrafluoroethylene / ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene / ethylene copolymer (ECTFE), polyvinyl fluoride (PVF) ), And a thermoplastic fluororesin (THV) and fluoroelastomer composed of three types of monomers such as tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride.

  Among these, the fluororesin used as the main component of the particles 5 includes polytetrafluoroethylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), tetrafluoroethylene / hexafluoropropylene copolymer, and tetrafluoroethylene / ethylene. A copolymer is preferred. By using these fluororesins as the main component of the particles 5, the outermost layer 3 having a relatively low dielectric constant, excellent strength, and improved surface lubricity can be formed. Furthermore, among these fluororesins, polytetrafluoroethylene which is structurally stable and excellent in lubricity is particularly preferable.

  The lower limit of the average particle size of the particles 5 is preferably 0.01 μm, and more preferably 0.1 μm. On the other hand, the upper limit of the average particle diameter of the particles 5 is preferably 5 μm and more preferably 3 μm. When the average particle diameter of the particles 5 is less than the lower limit, the surface lubricity of the outermost layer 3 may not be sufficiently improved. On the other hand, when the average particle diameter of the particles 5 exceeds the above upper limit, it may be difficult to uniformly disperse in the outermost layer 3, or the surface roughness of the outermost layer 3 becomes too large and the surface lubricity decreases. There is a fear.

  The lower limit of the content of the particles 5 in the outermost layer 3 is 0.5% by mass, preferably 1% by mass, and more preferably 2% by mass. On the other hand, the upper limit of the content of the particles 5 in the outermost layer 3 is 10% by mass, and preferably 8% by mass. When the content rate of the particles 5 in the outermost layer 3 is less than the lower limit, the surface lubricity of the outermost layer 3 may not be sufficiently improved. On the contrary, when the content rate of the particles 5 in the outermost layer 3 exceeds the lower upper limit, the strength of the outermost layer 3 may be insufficient, or the outermost layer 3 may be difficult to mold.

  The lower limit of the arithmetic average roughness of the outer peripheral surface of the outermost layer 3 is preferably 1.0 μm, more preferably 1.2 μm, and even more preferably 1.4 μm. On the other hand, the upper limit of the arithmetic average roughness is preferably 3.0 μm, more preferably 2.5 μm, and even more preferably 2.0 μm. Surface lubricity can be improved by making the said arithmetic mean roughness into the said range. The arithmetic average roughness is a value measured in accordance with JIS-B-0601 (2013) with an evaluation length (l) of 3000 nm and a cutoff value (λc) of 1000 nm.

  The lower limit of the dynamic friction coefficient when the self-lubricating insulated wires are crossed vertically and one of them is slid in the other length direction depends on the cross-sectional shape of the metal conductor 1, but 0.01 is preferable. 0.02 is more preferable. On the other hand, the upper limit of the dynamic friction coefficient is preferably 0.8, and more preferably 0.6. In particular, the upper limit of the dynamic friction coefficient when the metal conductor 1 has a circular cross-sectional shape is preferably 0.07, and more preferably 0.06. In order to make the dynamic friction coefficient less than the above lower limit, for example, further lubrication treatment such as application of a lubricant is required, so that the self-lubricating insulated wire may be expensive or may not be easily handled. On the other hand, when the dynamic friction coefficient exceeds the upper limit, for example, the outermost layer 3 and the inner layer 2 may be damaged during processing such as winding, and the insulating property of the self-lubricating insulated wire may be reduced.

  Here, the method for measuring the dynamic friction coefficient will be described with reference to FIGS. The dynamic friction coefficient is measured by applying a tension to the self-lubricating insulated wire and extending it by 1%. From the stretched self-lubricating insulated wire, two first test pieces S1 and two second test pieces S2 are obtained. Cut it out. In measuring the dynamic friction coefficient, first, the two first test pieces S1 are fixed in parallel on the fixed base 11. Next, two second test pieces S2 are fixed in parallel to the lower surface of the slider 12. The slider 12 is arranged on the fixed base 11 so that the first test piece S1 of the fixed base 11 and the second test piece S2 of the slider 12 are in perpendicular contact with each other. Subsequently, the upper surface of the slider 12 is pressed downward as indicated by a white arrow to apply a predetermined load to the first test piece S1 and the second test piece S2. Then, the wire 13 connected to the slider 12 is connected to the load cell 15 via the sheave 14, and the wire 12 is pulled to slide the slider 12 along the first test piece S 1 on the base 11. Using this apparatus, the slider 12 is slid to bring the first test piece S1 and the second test piece S2 into sliding contact, and the load of the load cell 15 is continuously measured by an autograph. Then, the dynamic friction coefficient is calculated from “the average load of the load cell when the slider is moving / the load pressing the slider downward (including the load of the slider)”. Here, the pulling speed of the slider 12 can be set to 200 mm / min, for example, and the load for pressing the slider 12 downward can be set to 1 kgf. It is preferable that this test is performed a plurality of times, and an average value of a plurality of test results is set as a dynamic friction coefficient.

[First manufacturing method of insulated wire]
Next, the 1st manufacturing method of the self-lubricating insulated wire of FIG. 1 is demonstrated.

  The self-lubricating insulated wire includes a first application step for applying the material forming the inner layer 2 to the outer peripheral surface of the metal conductor 1, and a first heating step for heating the material layer applied in the first application step. A second coating step in which an outermost layer forming material in which a plurality of particles 5 are dispersed in a material forming the matrix 4 is applied to the outer peripheral surface of the inner layer 2 formed in the first heating step; and the second coating step. And a second heating step of heating the layer of the outermost layer forming material applied in (1).

<First application process>
In the first application step, as a material for forming the inner layer 2, an inner layer varnish obtained by diluting the resin composition constituting the inner layer 2 with a solvent can be used.

  As the solvent for dilution, a known organic solvent conventionally used for the varnish for the inner layer can be used. Specifically, polar organic solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, tetramethylurea, hexaethylphosphoric triamide, and γ-butyrolactone are used. First, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, esters such as methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether (butyl cellosolve) ), Ethers such as diethylene glycol dimethyl ether and tetrahydrofuran, hydrocarbons such as hexane, heptane, benzene, toluene and xylene , Halogenated hydrocarbons such as dichloromethane and chlorobenzene, phenols such as cresol and chlorophenol, and tertiary amines such as pyridine. These organic solvents may be used alone or in combination of two or more. Used.

  In addition, as a minimum of the resin solid content density | concentration of the varnish for inner layers prepared by diluting with these organic solvents, 20 mass% is preferable and 22 mass% is more preferable. On the other hand, the upper limit of the resin solid content concentration of the inner layer varnish is preferably 50% by mass, more preferably 48% by mass. When the resin solid content concentration of the inner layer varnish is less than the lower limit, the amount of application at one time when the inner layer varnish is applied is reduced, so that the inner layer 2 having a desired thickness is formed. There is a possibility that the number of repetitions of the varnish application process increases and the time of the first application process becomes longer. Conversely, if the resin solids concentration of the inner layer varnish exceeds the above upper limit, it may be difficult to adjust the inner layer varnish or it may be difficult to apply the inner layer varnish thinly and uniformly. is there.

<First heating step>
In the first heating step, the first layer applied in the first application step is heated and baked. Thereby, the inner layer 2 is formed outside the metal conductor 1.

  When the inner layer 2 having a desired thickness cannot be formed by one application and baking of the inner layer varnish, the inner layer varnish may be repeatedly applied and baked until the inner layer 2 has a predetermined thickness. .

<Second application process>
In the second coating step, an outermost layer varnish obtained by diluting the material forming the matrix 4 with a solvent and further mixing a plurality of particles 5 can be used.

  As the solvent for diluting the outermost layer varnish, a known organic solvent conventionally used for the inner layer varnish can be used. Specifically, the diluting solvent used for the preparation of the inner layer varnish described above. And the same kind.

  The resin solid content concentration of the outermost layer varnish can be the same as the resin solid content concentration of the inner layer varnish.

<Second heating step>
In the second heating step, the second layer applied to the outer peripheral surface of the inner layer 2 in the second application step is heated and baked. Thereby, the outermost layer 3 is formed on the outer peripheral surface of the inner layer 2.

  When the outermost layer 3 having a desired thickness cannot be formed by one application and baking of the outermost layer varnish, the outermost layer varnish may be repeatedly applied and baked until the outermost layer 3 has a predetermined thickness.

[Second manufacturing method of insulated wire]
Next, another method for manufacturing the self-lubricating insulated wire shown in FIG. 1 will be described.

  The second manufacturing method of the self-lubricating insulated wire includes a step (extrusion coating step) of coating the outer peripheral surface of the metal conductor 1 with the inner layer 2 and the outermost layer 3 by coextrusion.

<Extrusion coating process>
In the extrusion coating process, the resin composition forming the inner layer 2, the resin composition forming the matrix 4, and the plurality of particles 5 are put into a melt extruder, and the inner layer 2 and the outermost layer 3 are formed from the metal conductor 1 side. The self-lubricating insulated wire is obtained by co-extrusion of these materials so that they are laminated in order.

  In addition, as the resin composition forming the inner layer 2 and the resin composition forming the matrix 4, those having a thermosetting resin as a main component may be used. However, as described above, a thermoplastic resin is the main component. Since the heating control at the time of co-extrusion can be easily performed, the self-lubricating insulated wire can be easily manufactured.

[advantage]
In the self-lubricating insulated wire, since the outermost layer 3 includes a plurality of particles 5 mainly composed of a fluororesin, the particles 5 are exposed on the surface of the outermost layer 3 and express the low friction property of the fluororesin. Since the frictional force is further reduced by forming fine irregularities on the outer peripheral surface of the outermost layer 3, the lubricity is excellent. For this reason, the self-lubricating insulated wire is relatively easy to be wound by winding the windings in close contact with each other, and it is possible to prevent the insulation layer from being damaged and the dielectric strength from being lowered during the processing.

[Other Embodiments]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configuration of the embodiment described above, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  The self-lubricating insulated wire may have no inner layer, or may have one or more additional insulating layers between the inner layer and the outermost layer.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example.

<Prototype example 1>
As the metal conductor, copper was cast, drawn, drawn and softened, and the cross section was circular and the diameter was 1.0 mm. The inner layer was formed using an inner layer varnish in which a polyimide precursor formed by polymerization of pyromellitic dianhydride and diaminodiphenyl ether was dissolved in N-methyl-2-pyrrolidone. Specifically, this inner layer varnish is applied to the outer peripheral surface of the metal conductor and baked under the conditions of a linear velocity of 3.0 m / min, a heating furnace inlet temperature of 350 ° C., and a heating furnace outlet temperature of 450 ° C. An inner layer having an average thickness of 40 μm was formed on the outer peripheral surface of the substrate. The outermost layer is prepared by dissolving a polyimide precursor formed by polymerization of pyromellitic dianhydride and diaminodiphenyl ether in N-methyl-2-pyrrolidone, and solidifying polytetrafluoroethylene particles having an average particle diameter of 1 μm. It was prepared using the varnish for the outermost layer dispersed so that the content rate in the base was 0.5% by mass. Specifically, by applying the outermost layer varnish to the outer periphery of the inner layer and repeatedly baking the wire under the conditions of a linear velocity of 3.0 m / min, a heating furnace inlet temperature of 350 ° C., and a heating furnace outlet temperature of 450 ° C. An outermost layer having an average thickness of 3 μm was formed on the outer peripheral surface of the inner layer, and an insulated wire of Prototype Example 1 was obtained.

<Prototype example 2>
Prototype Example 2 was created under the same conditions as Prototype Example 1 except that the particle content was 1% by mass.

<Prototype example 3>
Prototype Example 3 was created under the same conditions as Prototype Example 1 except that the particle content was 2 mass%.

<Prototype example 4>
Prototype Example 4 was created under the same conditions as Prototype Example 1 except that the particle content was 3 mass%.

<Prototype example 5>
Prototype Example 5 was created under the same conditions as Prototype Example 1 except that the particle content was 5 mass%.

<Prototype Example 6>
Prototype Example 6 was created under the same conditions as Prototype Example 1 except that the particle content was set to 10% by mass.

<Prototype Example 7>
Prototype Example 7 was prepared under the same conditions as in Prototype Example 1 except that the average particle diameter was 3 μm and the particle content was 3 mass%.

<Prototype Example 8>
Prototype Example 8 was prepared under the same conditions as Prototype Example 1 except that the average particle diameter was 12 μm and the particle content was 3 mass%.

<Prototype example 9>
Prototype Example 9 was created under the same conditions as Prototype Example 1 except that the particle content was 0 mass%.

<Prototype Example 10>
Prototype Example 10 was prepared under the same conditions as in Prototype Example 1 except that the material of the particles was a polytetrafluoroethylene / perfluoroalkyl vinyl ether copolymer and the particle content was 3% by mass.

<Prototype Example 11>
Prototype Example 11 uses a rectangular wire with a width of 3 mm and a height of 2 mm as the metal conductor, the average thickness of the inner layer is 80 μm, the particle content of the outermost layer is 5 mass%, and the average thickness is 6 μm. Except that, it was created under the same conditions as in Prototype Example 1.

<Prototype Example 12>
In Prototype Example 12, the outermost layer of Prototype Example 11 was omitted.

  About the above prototype examples 1-6, a dielectric breakdown voltage and the elongation rate of an insulating layer are measured, a winding test is performed, and furthermore, the insulated wires are crossed perpendicularly to each other and slide in one length direction. Was measured.

<Dielectric breakdown voltage>
The dielectric breakdown voltage was measured according to JIS-C3216-5 (2011).

<Elongation rate of insulating layer>
The elongation rate of the insulating layer was measured by a tensile tester by peeling the insulating layer of the insulated wire from the metal conductor into a cylindrical shape, and measuring the elongation at break of the cylindrical insulating layer. The elongation at break of this insulating layer was measured for two electric wires, and the average value was obtained.

<Winding test>
The winding test is carried out in accordance with JIS-C3216-3 (2011). “A” indicates that the appearance of the insulating layer is not abnormal, “B” indicates that the insulating layer is wrinkled, and exposure of the metal conductor is Some were rated “C”.

<Dynamic friction coefficient>
The dynamic friction coefficient was measured by the test method of FIG. 2 described above, assuming that the pulling speed of the slider was 200 mm / min and the load pressing the slider downward was 1 kgf.

  Table 1 below summarizes the preparation conditions, partial discharge start voltage, dielectric breakdown voltage, winding test result, and dynamic friction coefficient of each prototype. In addition, “-” in the table means that there is no corresponding configuration.

[Evaluation results]
As described above, it was confirmed that the outermost layer of the insulating layer has particles mainly composed of a fluororesin, thereby improving the surface lubricity and effectively preventing the insulating layer from being damaged during the winding process.

  Since the self-lubricating insulated wire according to the present invention is excellent in surface lubricity, it can be suitably used as a wire used by being wound.

DESCRIPTION OF SYMBOLS 1 Metal conductor 2 Inner layer 3 Outermost layer 4 Matrix 5 Particle | grains 11 Fixed base 12 Slider 13 Wire 14 Sheave 15 Load cell S1, S2 Test piece

Claims (6)

A linear metal conductor and one or more insulating layers laminated on the outer periphery of the metal conductor;
The outermost layer of the one or more insulating layers has a matrix mainly composed of a synthetic resin and a plurality of particles dispersed in the matrix and mainly composed of a fluororesin,
A self-lubricating insulated wire having a particle content of 0.5 mass% or more and 10 mass% or less in the outermost layer.   The self-lubricating insulated wire according to claim 1, wherein the average particle diameter of the particles is 0.01 µm or more and 5 µm or less.   The self-lubricating insulated wire according to claim 1 or 2, wherein a main component of the matrix is polyimide, polyamideimide or polyesterimide.   The self-lubricating insulated wire according to claim 1, 2, or 3, wherein the coefficient of dynamic friction is 0.8 or less.   The self-lubricating insulated wire according to any one of claims 1 to 4, wherein an average thickness of the outermost layer is 1 µm or more and 50 µm or less.   The main component of the particles is polytetrafluoroethylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer or tetrafluoroethylene / ethylene copolymer. The self-lubricating insulated wire according to any one of 5.

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