The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 06, 2022
Filed:
Feb. 06, 2018
Skc Co., Ltd., Gyeonggi-do, KR;
Dae Seong Oh, Seoul, KR;
Dawoo Jeong, Gyeonggi-do, KR;
Sunhwan Kim, Incheon, KR;
Jin Woo Lee, Gyeonggi-do, KR;
Dong Jin Lim, Gyeonggi-do, KR;
Cheol Ho Kim, Seoul, KR;
SKC CO., LTD., Gyeonggi-do, KR;
Abstract
An embodiment can provide a method for producing a polyamide-imide film which is colorless and transparent and has excellent mechanical properties, the method comprising: a step of producing a polyamide-imide polymer solution by polymerizing an aromatic diamine compound, an aromatic dianhydride compound, and a dicarbonyl compound; a step of producing a gel sheet by extruding, casting and drying the polymer solution; and a step of producing a polyamide-imide film by heat-treating the gel sheet, wherein the viscosity of the polymer solution is 100,000 to 500,000 cps, and the polyamide-imide film has a yellowness index of 5 or lower, a haze of 2% or lower, a transmittance of 85% or above and a modulus of 5.0 GPa or above, at a thickness of 20 μm to 75 μm.