US 12,215,255 B2
Biaxially oriented polyester film and laminated body
Noboru Tamari, Inuyama (JP); and Masayuki Haruta, Inuyama (JP)
Assigned to TOYOBO CO., LTD., Osaka (JP)
Appl. No. 18/247,974
Filed by TOYOBO CO., LTD., Osaka (JP)
PCT Filed Oct. 4, 2021, PCT No. PCT/JP2021/036623
§ 371(c)(1), (2) Date Apr. 5, 2023,
PCT Pub. No. WO2022/075260, PCT Pub. Date Apr. 14, 2022.
Claims priority of application No. 2020-169653 (JP), filed on Oct. 7, 2020.
Prior Publication US 2023/0374349 A1, Nov. 23, 2023
Int. Cl. C09J 7/25 (2018.01); B65D 65/40 (2006.01); C09J 167/03 (2006.01)
CPC C09J 7/255 (2018.01) [B65D 65/40 (2013.01); C09J 167/03 (2013.01); C09J 2301/122 (2020.08); C09J 2301/312 (2020.08); C09J 2301/414 (2020.08); C09J 2400/163 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A biaxially oriented polyester film, comprising at least a base layer and an adhesive layer each of which contains a polyester as a main component, wherein
the biaxially oriented polyester film satisfies the following requirements (1) to (3):
(1) a difference between reversible heat capacity differences (ΔCp) at around glass transition temperatures of the adhesive layer and the base layer is not smaller than 0.10 and not larger than 0.45;
(2) the biaxially oriented polyester film has a molecular orientation ratio measured by using a molecular orientation meter, the molecular orientation ratio being higher than 1.2; and
(3) the biaxially oriented polyester film has a stress at 10% elongation (F10) in each of a machine direction and a transverse direction, the stress at 10% elongation (F10) being not lower than 90 MPa and not higher than 160 MPa.