Insulated flat conductive wire having high aspect ratio, method for manufacturing same, and coil

Patent metadata

Field	Value
Publication number	US-2019066883-A1
Application number	US-201815937036-A
Country	US
Kind code	A1
Filing date	Mar 27, 2018
Priority date	Aug 22, 2017
Publication date	Feb 28, 2019
Grant date	—

Abstract

This insulated flat conductive wire includes: a flat conductive wire having an aspect ratio a/b of 12 or more, wherein the aspect ratio is a ratio of a length a of a long side of a rectangular cross-section to a length b of a short side thereof; and an insulating film which consists of a polyamide-imide resin or a polyimide resin and coats the flat conductive wire, wherein the insulating film has a film thickness t1 of 10 μm or more at a center portion of the long side of the rectangular cross-section, and the insulating film has a film thickness ratio t1/t2 of 0.80 to 1.35, and wherein the film thickness ratio t1/t2 is a ratio of the film thickness t1 at the center portion of the long side to a film thickness t2 at an edge portion of the long side of the rectangular cross-section.

First claim

1 . An insulated flat conductive wire having a high aspect ratio, comprising:
a flat conductive wire having an aspect ratio a/b of 12 or more, wherein the aspect ratio is a ratio of a length a of a long side of a rectangular cross-section to a length b of a short side thereof; and an insulating film which consists of a polyamide-imide resin or a polyimide resin and coats the flat conductive wire, wherein the insulating film has a film thickness t1 of 10 μm or more at a center portion of the long side of the rectangular cross-section, and the insulating film has a film thickness ratio t1/t2 of 0.80 to 1.35, and wherein the film thickness ratio t1/t2 is a ratio of the film thickness t1 at the center portion of the long side to a film thickness t2 at an edge portion of the long side of the rectangular cross-section.

2 . The insulated flat conductive wire having a high aspect ratio according to claim 1 ,
wherein the polyamide-imide resin or the polyimide resin has a number average molecular weight Mn of 2.0×10 4 to 4.0×10 4 .

3 . A coil comprising:
the insulated flat conductive wire having a high aspect ratio according to claim 1 which is coiled.

4 . A coil comprising:
the insulated flat conductive wire having a high aspect ratio according to claim 2 which is coiled.

5 . A method for manufacturing the insulated flat conductive wire having a high aspect ratio according to claim 1 , the method comprising:
an electrodeposition solution preparation step of mixing a polyamide-imide resin or a polyimide resin having a number average molecular weight Mn of 2.0×10 4 to 4.0×10 4 , a polar organic solvent, and a base, stirring the mixture at a temperature of 20° C. to 25° C. for 3 hours or more to obtain a mixed solution, and subsequently adding water to the mixed solution to prepare an electrodeposition solution; an electrodeposition step of immersing a flat conductive wire having an aspect ratio a/b of 12 or more in the electrodeposition solution, wherein the aspect ratio is a ratio of a length a of a long side of a rectangular cross-section to a length b of a short side thereof, and causing a direct current to flow at a voltage of 150 V or higher in the electrodeposition solution, thereby electrodepositing particles of the polyamide-imide resin or the polyimide resin on a surface of the flat conductive wire; and a baking step of heating the flat conductive wire, on which the particles of the polyamide-imide resin or the polyimide resin have been electrodeposited, to form an insulating film on the surface of the flat conductive wire.

6 . The method for manufacturing the insulated flat conductive wire having a high aspect ratio according to claim 5 ,
wherein the baking step includes: a low-temperature heating step of heating the flat conductive wire, on which the particles of the polyamide-imide resin or the polyimide resin have been electrodeposited, at a low temperature of 150° C. to 220° C. for 0.25 to 30 minutes; and a high-temperature heating step of heating the flat conductive wire, which has been heated at the low temperature, at a high temperature that is 30° C. or more higher than the temperature in the low-temperature heating step for 0.25 to 30 minutes.

Assignees

• Mitsubishi Materials Corp

Inventors

• Sakurai Hideaki
• Hirano Koji

Classifications

• C09D5/4461

  Polyamides; Polyimides · CPC title

• H01F5/06

  Insulation of windings · CPC title

• C25D9/02

  with organic materials · CPC title

• H01B13/06

  Insulating conductors or cables (H01B13/32 takes precedence) · CPC title

• H01F41/12

  Insulating of windings ({impregnating or encapsulating of transformers H01F41/005} ; of conductors in general H01B13/06) · CPC title