US 11,728,068 B2
Magnet wire with corona resistant polyimide insulation
Matthew Leach, Fort Wayne, IN (US); James J. Connell, Fort Wayne, IN (US); Allen Roe Guisinger, Huntertown, IN (US); Allan R. Knerr, Fort Wayne, IN (US); Frederick Marshall McFarland, Fort Wayne, IN (US); Tamanna Ferdous McFarland, Fort Wayne, IN (US); and Mohammad Mazhar Said, South Barrington, IL (US)
Assigned to Essex Furukawa Magnet Wire USA LLC, Atlanta, GA (US)
Filed by Essex Furukawa Magnet Wire USA LLC, Atlanta, GA (US)
Filed on Apr. 28, 2022, as Appl. No. 17/731,350.
Application 17/731,350 is a continuation in part of application No. 17/316,333, filed on May 10, 2021, granted, now 11,352,521.
Application 17/316,333 is a continuation in part of application No. 17/003,503, filed on Aug. 26, 2020, granted, now 11,004,575, issued on Apr. 21, 2021.
Application 17/003,503 is a continuation in part of application No. 16/403,665, filed on May 6, 2019, granted, now 10,796,820, issued on Sep. 16, 2020.
Claims priority of provisional application 62/667,649, filed on May 7, 2018.
Prior Publication US 2022/0254542 A1, Aug. 11, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H01B 3/02 (2006.01); H01B 3/30 (2006.01)
CPC H01B 3/306 (2013.01) [H01B 3/305 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A magnet wire comprising:
a conductor; and
an insulation system formed around the conductor, the insulation system comprising:
a basecoat of first polymeric enamel insulation having a first thickness that is between forty-five percent and sixty-five percent of a total thickness of the insulation system;
a midcoat of second polymeric enamel insulation formed around the basecoat and having a second thickness that is between twenty-five percent and forty percent of the total thickness, the second polymeric enamel insulation comprising a filler dispersed in a base polyimide material, wherein the filler comprises between 20 percent and 80 percent by weight of silica dioxide and between 20 and 80 percent by weight of titanium dioxide; and
a topcoat of third polymeric enamel insulation formed around the midcoat and having a third thickness that is between five percent and fifteen percent of the total thickness.