US 12,428,532 B2
Method for producing polyamide resin film
Akiko Kurosawa, Uji (JP); and Atsuko Noda, Uji (JP)
Assigned to UNITIKA LTD., Osaka (JP)
Filed by UNITIKA LTD., Osaka (JP)
Filed on Apr. 28, 2023, as Appl. No. 18/308,997.
Application 18/308,997 is a division of application No. 17/794,030, granted, now 12,012,491, previously published as PCT/JP2021/002310, filed on Jan. 22, 2021.
Claims priority of application No. 2020-010068 (JP), filed on Jan. 24, 2020.
Prior Publication US 2023/0257539 A1, Aug. 17, 2023
Int. Cl. C08J 5/18 (2006.01); B32B 27/34 (2006.01); C08J 11/10 (2006.01); C08L 77/02 (2006.01)
CPC C08J 5/18 (2013.01) [B32B 27/34 (2013.01); C08J 11/10 (2013.01); C08L 77/02 (2013.01); B32B 2272/00 (2013.01); B32B 2305/70 (2013.01); B32B 2307/518 (2013.01); B32B 2307/704 (2013.01); B32B 2307/75 (2013.01); B32B 2439/00 (2013.01); C08L 2207/20 (2013.01); Y02P 20/143 (2015.11); Y02W 30/62 (2015.05)] 6 Claims
OG exemplary drawing
 
1. A method for producing a polyamide resin film, the method comprising:
(1) a step of producing a monomer from a raw material (A) for depolymerization;
(2) a step of producing a polyamide resin (B) through polymerization using a raw material containing the monomer;
(3) a step of refining the polyamide resin (B); and
(4) a step of producing an unstretched film using a starting material containing the refined polyamide resin (B), and stretching the unstretched film, wherein the starting material partly contains a remelted resin obtained by melting a polyamide resin (provided that the polyamide resin (B) is excluded) and a content of the remelted resin is 1 mass % or more.