US 11,955,258 B2
Laminate of conductor and insulating coating, coil, rotating electric machine, insulating paint, and insulating film
Noriyuki Hayashizaka, Hyogo (JP); Seiji Bando, Hyogo (JP); and Hideyuki Kikuchi, Hitachi (JP)
Assigned to SUMITOMO SEIKA CHEMICALS CO., LTD., Hyogo (JP); and HIDE TECHNOLOGY, LLC, Hitachi (JP)
Appl. No. 17/250,771
Filed by SUMITOMO SEIKA CHEMICALS CO., LTD., Hyogo (JP); and HIDE TECHNOLOGY, LLC, Hitachi (JP)
PCT Filed Mar. 27, 2019, PCT No. PCT/JP2019/013120
§ 371(c)(1), (2) Date Mar. 2, 2021,
PCT Pub. No. WO2020/049784, PCT Pub. Date Mar. 12, 2020.
Claims priority of application No. 2018-164717 (JP), filed on Sep. 3, 2018.
Prior Publication US 2021/0202128 A1, Jul. 1, 2021
Int. Cl. H01B 7/02 (2006.01); C09D 7/61 (2018.01); H01B 3/30 (2006.01); H01B 3/42 (2006.01); H01F 5/06 (2006.01); C08K 3/22 (2006.01)
CPC H01B 7/0216 (2013.01) [C09D 7/61 (2018.01); H01B 3/302 (2013.01); H01B 3/308 (2013.01); H01B 3/421 (2013.01); H01F 5/06 (2013.01); C08K 3/22 (2013.01); C08K 2003/2227 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A laminate comprising at least a conductor, an insulating coating, a composite layer and an inorganic insulating layer, wherein:
the insulating coating is formed of a resin composition containing a metal oxide hydrate,
the resin composition contains the metal oxide hydrate in an amount of 6 to 50 parts by mass per 100 parts by mass of the resin, wherein the metal oxide hydrate is in a shape of flat fine particles having a high aspect ratio (one side/thickness) of 4 to 200,
the resin in the resin composition is at least one selected from the group consisting of a polyamide-imide, a polyimide, and precursors thereof,
the inorganic insulating layer is formed on the insulating coating when the laminate is exposed to partial discharge caused by inverter surges occurring due to switching at a frequency of 1 to 100 kHz, and the composite layer is also formed between the conductor and the inorganic insulating layer, wherein a thickness of the inorganic insulating layer is 10 nm or more and wherein a void ratio of the inorganic insulating layer is lower than 20%, and
the composite layer contains a mixture of the resin and the metal oxide hydrate contained in the insulating coating, and a metal oxide or a metal oxide hydrate formed by dehydration of the metal oxide hydrate contained in the inorganic insulating layer, wherein the composite layer contains voids that are formed upon elimination of a portion of the resin from the composite layer by the partial discharge, wherein a void ratio of the composite layer is 20% or more.