US 12,378,051 B2
Packaging bag
Masahiro Hongo, Yokohama (JP); Takahiro Kurosawa, Yokohama (JP); Takashi Miura, Yokohama (JP); Kazuaki Ohashi, Yokohama (JP); Yoshiyuki Yuasa, Yokohama (JP); and Takahiro Akahane, Yokohama (JP)
Assigned to TOYO SEIKAN CO., LTD., Tokyo (JP); and TOYO SEIKAN GROUP HOLDINGS, LTD., Tokyo (JP)
Appl. No. 17/414,202
Filed by TOYO SEIKAN CO., LTD., Tokyo (JP); and TOYO SEIKAN GROUP HOLDINGS, LTD., Tokyo (JP)
PCT Filed Dec. 5, 2019, PCT No. PCT/JP2019/047555
§ 371(c)(1), (2) Date Jun. 15, 2021,
PCT Pub. No. WO2020/129662, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 2018-235672 (JP), filed on Dec. 17, 2018; and application No. 2019-014090 (JP), filed on Jan. 30, 2019.
Prior Publication US 2022/0024660 A1, Jan. 27, 2022
Int. Cl. B65D 65/40 (2006.01); B32B 1/00 (2024.01); B32B 7/12 (2006.01); B32B 27/08 (2006.01); B32B 27/36 (2006.01); B65D 75/00 (2006.01); B65D 75/58 (2006.01); B65D 81/34 (2006.01)
CPC B65D 65/40 (2013.01) [B32B 1/00 (2013.01); B32B 7/12 (2013.01); B32B 27/08 (2013.01); B32B 27/36 (2013.01); B65D 75/008 (2013.01); B65D 75/5805 (2013.01); B65D 81/3461 (2013.01); B32B 2250/03 (2013.01); B32B 2250/244 (2013.01); B32B 2255/10 (2013.01); B32B 2255/20 (2013.01); B32B 2270/00 (2013.01); B32B 2307/31 (2013.01); B32B 2307/518 (2013.01); B32B 2439/46 (2013.01); B32B 2439/70 (2013.01); B65D 2581/3428 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A packaging bag comprising a polyester-based multilayer film, the multilayer film including at least: an innermost layer formed of a biaxially stretched polyethylene terephthalate film; and a layer formed of a blend of polyethylene terephthalate and polybutylene terephthalate, the multilayer film further including a layer formed of a polyethylene terephthalate film, wherein a blend ratio (mass ratio) of polyethylene terephthalate to polybutylene terephthalate in the blend is in a range of 10:90 to 90:10;
the layer formed of the blend of polyethylene terephthalate and polybutylene terephthalate has a thickness of 5 to 50 um;
the innermost layer has a thickness of 5 to 50 μm;
the multilayer film as a whole has a thickness of 20 to 100 μm;
the biaxially stretched polyethylene terephthalate film has a heat sealing portion that is amorphized or low-crystallized by laser light irradiation under conditions including each of: an output of 10 to 400 W; a spot diameter of 0.14 to 15 nmmm; a scanning line interval of 0.05 to 15 mm; and an irradiation energy density of 0.5 to 8 J/cm2, and the packaging bag is formed by: allowing the innermost layers of the polyester-based multilayer film to be opposed to and superimposed on each other; and heat sealing the heat sealing portions; and
the layer formed of a polyethylene terephthalate film is an outermost layer that is formed of a biaxially stretched polyethylene terephthalate and has an easy-opening portion that is amorphized or low-crystallized by laser light irradiation under conditions including each of: an output of 10 to 400 W; a spot diameter of 0.14 to 15 mm; a scanning line interval of 0.05 to 15 mm; and an irradiation energy density of 0.5 to 8 J/cm2, and an intermediate layer located between the outermost layer and the innermost layer has a slit.