US 11,905,431 B2
Polyimide varnish comprising aromatic carboxylic acid for conductor coating and manufacturing method therefor
In Hwan Hwang, Seoul (KR); Ik Sang Lee, Gyeongsangbuk-do (KR); and Jeong Yeul Choi, Gyeonggi-do (KR)
Assigned to PI ADVANCED MATERIALS CO., LTD., Chungcheongbuk-do (KR)
Appl. No. 17/270,006
Filed by PI ADVANCED MATERIALS CO., LTD., Chungcheongbuk-do (KR)
PCT Filed Nov. 13, 2018, PCT No. PCT/KR2018/013804
§ 371(c)(1), (2) Date Feb. 20, 2021,
PCT Pub. No. WO2020/040356, PCT Pub. Date Feb. 27, 2020.
Claims priority of application No. 10-2018-0097929 (KR), filed on Aug. 22, 2018; and application No. 10-2018-0128186 (KR), filed on Oct. 25, 2018.
Prior Publication US 2021/0198521 A1, Jul. 1, 2021
Int. Cl. C09D 179/08 (2006.01); H01B 3/30 (2006.01); H01B 13/06 (2006.01); C08K 5/092 (2006.01); C08K 5/521 (2006.01)
CPC C09D 179/08 (2013.01) [C08K 5/092 (2013.01); H01B 3/306 (2013.01); H01B 13/06 (2013.01); C08K 5/521 (2013.01)] 22 Claims
 
1. A polyimide varnish for conductor coating,
the polyimide varnish comprising: a polyamic acid solution prepared through polymerization of at least one dianhydride monomer and at least one diamine monomer in an organic solvent;
an aromatic carboxylic acid having four or more carboxyl groups;
an alkoxy silane coupling agent; and
an antioxidant,
wherein the polyimide varnish has a solid content of 15 to 38 wt % on the basis of the total weight thereof, and
a viscosity at 23° C. of 500 to 9.000 cP, and
the coated material prepared from the polyimide varnish has a degree of softening resistance of 520° C. or higher, and a breakdown voltage (BDV) of 8 kV/mm or higher.