US 12,291,821 B2
Heat-sealable paper and packaging bag
Tomofumi Isozaki, Tokyo (JP); Yasutomo Noishiki, Tokyo (JP); Masahiro Tsuruhara, Tokyo (JP); Yuta Shamoto, Tokyo (JP); and Miyoko Tanaka, Tokyo (JP)
Assigned to OJI HOLDINGS CORPORATION, Tokyo (JP)
Appl. No. 17/927,651
Filed by OJI HOLDINGS CORPORATION, Tokyo (JP)
PCT Filed May 21, 2021, PCT No. PCT/JP2021/019315
§ 371(c)(1), (2) Date Nov. 23, 2022,
PCT Pub. No. WO2021/241427, PCT Pub. Date Dec. 2, 2021.
Claims priority of application No. 2020-091869 (JP), filed on May 27, 2020; and application No. 2020-217000 (JP), filed on Dec. 25, 2020.
Prior Publication US 2023/0243106 A1, Aug. 3, 2023
Int. Cl. D21H 27/10 (2006.01); B65D 65/02 (2006.01); B65D 65/40 (2006.01); D21H 11/04 (2006.01); D21H 19/40 (2006.01); D21H 19/58 (2006.01); D21H 19/60 (2006.01)
CPC D21H 27/10 (2013.01) [B65D 65/02 (2013.01); B65D 65/40 (2013.01); D21H 11/04 (2013.01); D21H 19/40 (2013.01); D21H 19/58 (2013.01); D21H 19/60 (2013.01)] 12 Claims
 
1. A heat-sealable paper comprising:
a paper substrate; and
at least one heat-sealable layer formed on at least one surface of the paper substrate, wherein
the paper substrate comprises raw material pulp containing softwood pulp as a main component and a dry paper strength additive,
the heat-sealable layer comprises a water-dispersible resin binder and a lubricant,
the water-dispersible resin binder comprises at least one selected from the group consisting of an ethylene-(meth)acrylic acid copolymer and a styrene/butadiene copolymer, in which,
when the water-dispersible resin binder comprises the ethylene-(meth)acrylic acid copolymer, the lubricant comprises carnauba wax, or
when the water-dispersible resin binder comprises the styrene/butadiene copolymer, the lubricant comprises paraffin wax, and
in the paper substrate, when a tensile energy absorption in a longitudinal direction of the paper substrate as measured in accordance with JIS P 8113:2006 is defined as X1, a tensile energy absorption in a transverse direction of the paper substrate as measured in accordance with JIS P 8113:2006 is defined as Y1, a tensile energy absorption index in the longitudinal direction as measured in accordance with JIS P 8113:2006 is defined as X2, and a tensile energy absorption index in the transverse direction as measured in accordance with JIS P 8113:2006 is defined as Y2, a geometric mean of X1 and Y1 is 120 J/m2 or more, a ratio of X1 to Y1 (X1/Y1) is 0.5 or more and 2.0 or less, and a geometric mean of X2 and Y2 is 2.0 J/g or more.