	US 12,112,957 B2
	Release film and method of manufacturing release film
Keisuke Sakai, Matsudo (JP); Norifumi Iwawaki, Matsudo (JP); Nanae Tanaka, Matsudo (JP); Satoshi Hiramatsu, Matsudo (JP); and Akane Kawafuchi, Matsudo (JP)
Assigned to KOBAYASHI & CO., LTD., Tokyo (JP)
Appl. No. 17/252,136
Filed by KOBAYASHI & CO., LTD., Tokyo (JP)
PCT Filed Apr. 8, 2019, PCT No. PCT/JP2019/015352 § 371(c)(1), (2) Date Dec. 14, 2020, PCT Pub. No. WO2019/244447, PCT Pub. Date Dec. 26, 2019.
Claims priority of application No. 2018-119269 (JP), filed on Jun. 22, 2018.
Prior Publication US 2021/0257228 A1, Aug. 19, 2021
Int. Cl. B32B 3/10 (2006.01); B29C 33/68 (2006.01); H01L 21/56 (2006.01); H01L 23/29 (2006.01)

CPC H01L 21/566 (2013.01) [B29C 33/68 (2013.01); H01L 23/293 (2013.01)]

11 Claims

1. A release film comprising:

a base layer formed of an easily moldable polyethylene terephthalate resin; and

surface layers laminated on two faces of the base layer and formed of a fluororesin;

wherein the easily moldable polyethylene terephthalate resin has a glass transition temperature of 60° C. to 95° C.,

the fluororesin that forms the surface layer comprises a tetrafluoroethylene resin, and the fluororesin that forms the surface layer on at least one face of the base layer comprises particles having an average particle size of 1 μm to 10 μm determined by laser diffraction particle size analysis, and contains a combination of isocyanate-type polyisocyanate and an adduct-type polyisocyanate.