公开(公告)号：US20240239978A1

公开(公告)日：2024-07-18

申请号：US18559237

申请日：2022-05-04

Applicant: TORAY ADVANCED MATERIALS KOREA INC.

Inventor： Min Gi HONG ,  Young Ho KIM

IPC: C08J5/18 ,  B29C48/00 ,  B29C48/08 ,  B29C55/00 ,  B29C55/14 ,  B29C55/18 ,  B29K67/00 ,  B29K105/16 ,  B29K509/00 ,  C08K3/36 ,  H01M50/414 ,  H01M50/434 ,  H01M50/446 ,  H01M50/489

CPC classification number: C08J5/18 ,  C08K3/36 ,  H01M50/414 ,  H01M50/434 ,  H01M50/446 ,  H01M50/489 ,  B29C48/0018 ,  B29C48/08 ,  B29C55/005 ,  B29C55/14 ,  B29C55/18 ,  B29K2067/003 ,  B29K2105/16 ,  B29K2509/00 ,  C08J2367/02 ,  C08K2201/005

Abstract: A biaxially oriented polyester film according to the present invention is a biaxially oriented polyester film comprising inorganic particles and a polyester resin, wherein the hardness of a roll obtained by slitting a master roll on which the biaxially oriented polyester film is wound and then by being rewound thereon at a winding tension of 6.5 kg/m to 8.5 kg/m, a winding surface pressure of 35 kg/m to 50 kg/m and a winding rate of 300 m/min to 350 m/min, is 90 to 95 points. The biaxially oriented polyester film prevents the roll from forming wrinkles over time in a roll wound state, and therefore when used as an interlayer of a secondary battery separator, can prevent wrinkles from transferring onto the separator.