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US-20260128190-A1 - RECTANGULAR WIRE AND PRODUCTION METHOD FOR SAME

US20260128190A1US 20260128190 A1US20260128190 A1US 20260128190A1US-20260128190-A1

Abstract

The present invention pertains to a rectangular wire including: a rectangular conductor; and a film of an insulating coating material that directly covers the entire circumferential direction of the rectangular conductor, wherein: a melt flow rate of the insulating coating material at a temperature of 372° C. and a load of 49 N is from 20.0 to 300.0 g/10 min; the insulating coating material contains polyaryletherketone (A) and a fluorine-containing copolymer (B) having a unit based on tetrafluoroethylene; an amount of the fluorine-containing copolymer (B) with respect to a total mass of the polyaryletherketone (A) and the fluorine-containing copolymer (B) in the insulating coating material is 5% by mass or more; and the rectangular wire is such that the film of the insulating coating material does not peel off from the rectangular conductor in a winding test conforming to “JIS3216-3:2011 5.1.2 Rectangular Wire”.

Inventors

  • Masatoshi Abe
  • Toru Sasaki
  • Tsuyoshi Kawai

Assignees

  • AGC Inc.

Dates

Publication Date
20260507
Application Date
20251009
Priority Date
20230412

Claims (11)

  1. 1 . A rectangular wire comprising: a rectangular conductor having a rectangular cross section in a direction perpendicular to the axial direction; and a film of an insulating coating material formed by extrusion molding that directly covers the entire circumferential direction of said rectangular conductor, wherein: a melt flow rate of said insulating coating material at a temperature of 372° C. and a load of 49 N is from 20.0 to 300.0 g/10 min; an average thickness of the film of said insulating coating material is from 10 to 1,000 μm; an unbiased standard deviation of a thickness of the film of said insulating coating material in the axial direction of said rectangular wire is less than 0.06 mm; said insulating coating material comprises polyaryletherketone (A) and a fluorine-containing copolymer (B) having a unit based on tetrafluoroethylene; said fluorine-containing copolymer (B) comprises one or more selected from the group consisting of a fluorine-containing resin (B1) having a melting point of 260° C. or higher and a fluorine-containing elastomer (B2); an amount of said fluorine-containing copolymer (B) with respect to a total mass of said polyaryletherketone (A) and said fluorine-containing copolymer (B) in said insulating coating material is 5% by mass or more; and said rectangular wire is such that the film of said insulating coating material does not peel off from said rectangular conductor in a winding test conforming to “JIS3216-3:2011 5.1.2 Rectangular Wire”.
  2. 2 . The rectangular wire according to claim 1 , wherein a cross sectional area of said rectangular conductor is 2.6 mm 2 or more.
  3. 3 . The rectangular wire according to claim 1 , wherein said fluorine-containing resin (B1) has a —CH 2 OH group, and an amount of said —CH 2 OH group is more than 30 with respect to 1×10 6 main chain carbon atoms of said fluorine-containing resin (B1).
  4. 4 . The rectangular wire according to claim 1 , wherein said fluorine-containing elastomer (B2) has an iodine atom, and an amount of said iodine atom is 0.05% by mass or more with respect to a total mass of said fluorine-containing elastomer (B2).
  5. 5 . The rectangular wire according to claim 1 , wherein a partial discharge inception voltage of said insulating coating material is 600 Vrms or more.
  6. 6 . A method for producing a rectangular wire including a rectangular conductor having a rectangular cross section in a direction perpendicular to the axial direction, and a film of an insulating coating material formed by extrusion molding that directly covers the entire circumferential direction of said rectangular conductor, the method comprising: melting a composition containing polyaryletherketone (A) and a fluorine-containing copolymer (B) having a unit based on tetrafluoroethylene using an extruder equipped with a die; and extruding said composition that has been melted from said die around said rectangular conductor; thereby coating around said rectangular conductor with said melted composition and forming said insulating coating material, wherein: a melt flow rate of said insulating coating material at a temperature of 372° C. and a load of 49 N is from 20.0 to 300.0 g/10 min; an average thickness of the film of said insulating coating material is from 10 to 1,000 μm; an unbiased standard deviation of a thickness of the film of said insulating coating material in the axial direction of said rectangular wire is less than 0.06 mm; said fluorine-containing copolymer (B) comprises one or more selected from the group consisting of a fluorine-containing resin (B1) having a melting point of 260° C. or higher and a fluorine-containing elastomer (B2); an amount of said fluorine-containing copolymer (B) with respect to a total mass of said polyaryletherketone (A) and said fluorine-containing copolymer (B) in said composition is 5% by mass or more; and said rectangular wire is such that the film of said insulating coating material does not peel off from said rectangular conductor in a winding test conforming to “JIS3216-3:2011 5.1.2 Rectangular Wire”.
  7. 7 . The method for producing a rectangular wire according to claim 6 , wherein a drawdown ratio DDR calculated by the following Formula 1 is 0.5 or more and less than 10.0, DDR = ( D A - C A ) / ( F A - C A ) Formula ⁢ 1 wherein D A is an opening area (mm 2 ) of said die, C A is a cross sectional area (mm 2 ) of said rectangular conductor in a direction perpendicular to the axial direction, and F A is a cross sectional area (mm 2 ) of said rectangular wire in a direction perpendicular to the axial direction.
  8. 8 . The method for producing a rectangular wire according to claim 6 , wherein a cross sectional area of said rectangular conductor is 2.6 mm 2 or more.
  9. 9 . The method for producing a rectangular wire according to claim 6 , wherein said fluorine-containing resin (B1) has a —CH 2 OH group, and an amount of said —CH 2 OH group is more than 30 with respect to 1×10 6 main chain carbon atoms of said fluorine-containing resin (B1).
  10. 10 . The method for producing a rectangular wire according to claim 6 , wherein said fluorine-containing elastomer (B2) has an iodine atom, and an amount of said iodine atom is 0.05% by mass or more with respect to a total mass of said fluorine-containing elastomer (B2).
  11. 11 . The method for producing a rectangular wire according to claim 6 , wherein a partial discharge inception voltage of said insulating coating material is 600 Vrms or more.

Description

This application is a continuation application of International Application No. PCT/JP2024/014823, filed on Apr. 12, 2024, which claims the benefit of priority of the prior Japanese Patent Application No. 2023-064886, filed Apr. 12, 2023 in Japan, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a rectangular wire and a production method of the same. Description of the Related Art Vehicle equipment or the like used in automobiles, railroads, aircraft, and the like is desired to be smaller and lighter. Therefore, a film of an insulating coating material of an insulated electric wire of an electrical equipment used in the vehicle equipment is required to be thinner. Furthermore, with the increase in the output and voltage of electrical equipment, the above insulating coating material is required to have excellent insulation properties as well as strong adhesion to a conductor. By employing a rectangular conductor as a conductor of an electric wire, the space factor is higher when it is coiled, as compared to a round wire. As a result, it is possible to save space in the entire coil, which contributes to the miniaturization of electrical equipment. However, in the case of rectangular conductors, it is more difficult to form a uniform film of an insulating coating material compared to round wires, and there is a problem in that the insulation properties cannot be sufficiently maintained. Patent Document 1 discloses a method for producing a rectangular wire in which a powder having an average particle size of 0.02 μm or more and 150 μm or less and containing a melt-moldable fluororesin with a melting point of 100° C. or higher and 325° C. or lower and at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group is coated onto a rectangular conductor, thereby forming a film of an insulating coating layer with a thickness of 10 to 150 μm on the outer periphery of the rectangular conductor. PRIOR ART DOCUMENTS Patent Document [Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2017-204410 SUMMARY OF THE INVENTION Problems to be Solved by the Invention However, the production method described in Patent Document 1 requires a powder preparation step and a firing step after the powder coating, which results in a problem of low productivity. In addition, since the powder is coated, there is a problem of low surface smoothness of the film of the insulating coating material. Furthermore, the film of the insulating coating material exhibits low conformability with respect to the rectangular conductor, and during bending deformation of the rectangular wire, there are also problems of wrinkles forming in the film of the insulating coating material or the film of the insulating coating material peeling off from the rectangular conductor. The present invention has an object of providing: a rectangular wire that is highly productive and exhibits excellent surface smoothness of the film of the insulating coating material and conformability of the film of the insulating coating material with respect to the rectangular conductor during bending deformation; as well as a production method thereof. Means for Solving the Problem The present invention includes the following aspects. [1] A rectangular wire including: a rectangular conductor having a rectangular cross section in a direction perpendicular to the axial direction; and a film of an insulating coating material formed by extrusion molding that directly covers the entire circumferential direction of the aforementioned rectangular conductor, wherein a melt flow rate of the aforementioned insulating coating material at a temperature of 372° C. and a load of 49 N is from 20.0 to 300.0 g/10 min, an average thickness of the film of the aforementioned insulating coating material is from 10 to 1,000 μm, an unbiased standard deviation of a thickness of the film of the aforementioned insulating coating material in the axial direction of the aforementioned rectangular wire is less than 0.06 mm, the aforementioned insulating coating material contains polyaryletherketone (A) and a fluorine-containing copolymer (B) having a unit based on tetrafluoroethylene, the aforementioned fluorine-containing copolymer (B) contains one or more selected from the group consisting of a fluorine-containing resin (B1) having a melting point of 260° C. or higher and a fluorine-containing elastomer (B2), an amount of the aforementioned fluorine-containing copolymer (B) with respect to a total mass of the aforementioned polyaryletherketone (A) and the aforementioned fluorine-containing copolymer (B) in the aforementioned insulating coating material is 5% by mass or more, and the aforementioned rectangular wire is such that the film of the aforementioned insulating coating material does not p