Film, laminated film, and packaging bag
This film includes a first resin layer formed of a high-density polyethylene (HDPE) and a second resin layer formed of a medium-density polyethylene (MDPE) made to be adjacent to each other by co-extrusion, in which the first resin layer and the second resin layer are stretched in the same direction. In addition, the film may include a first surface layer formed of a high-density polyethylene (HDPE), an intermediate layer formed of a medium-density polyethylene (MDPE), and a second surface layer formed of a medium-density polyethylene (MDPE) made to be adjacent to each other in this order by co-extrusion, and the first surface layer, the intermediate layer and the second surface layer are stretched in the same direction.
1 . A laminated film comprising a resin film and a sealant layer laminated on the resin film:
wherein the resin film comprises a first resin layer formed of a high-density polyethylene (HDPE) and a second resin layer formed of a medium-density polyethylene (MDPE), the first resin layer and the second resin layer being made to be adjacent to each other by coextrusion, and the first resin layer and the second resin layer are stretched in the same direction,
the high-density polyethylene (HDPE) has a density higher than 940 kg/m 3 ,
the medium-density polyethylene (MDPE) has a density of higher than 925 kg/m 3 and 940 kg/m 3 or less,
the thickness of the first resin layer is 5 to 25 μm,
the thickness of the second resin layer is 5 to 45 μm,
the second resin layer is thicker than the first resin layer,
the sealant layer is formed of a polyethylene-based resin selected from a linear low density polyethylene (LLDPE) and a low-density polyethylene (LDPE),
the first resin layer is disposed opposite to the sealant layer,
the sealant layer is bonded to the second resin layer,
the thickness of the sealant layer is 60 to 180 μm, and
a proportion of the sealant layer to the thickness of the laminated film is 50% or more.
2 . The laminated film according to claim 1 ,
wherein the resin film comprises an intermediate layer formed of a medium-density polyethylene (MDPE) between a first surface layer being the first resin layer and a second surface layer being the second resin layer; and
the first surface layer, the intermediate layer and the second surface layer are made to be adjacent to each other in this order by co-extrusion, and
the first surface layer, the intermediate layer and the second surface layer are stretched in the same direction.
3 . The laminated film according to claim 2 , wherein the intermediate layer contains an additive other than resins.
4 . The laminated film according to claim 1 , wherein a stretch ratio in the same direction is twice to 10 times.
5 . The laminated film according to claim 1 , wherein the sealant layer is formed of a non-stretched polyethylene-based resin.
6 . The laminated film according to claim 2 , wherein a stretch ratio in the same direction is twice to 10 times.
7 . The laminated film according to claim 2 , wherein the sealant layer is formed of a non-stretched polyethylene-based resin.
8 . A packaging bag, wherein at least one member is formed of the laminated film according to claim 1 .
9 . A packaging bag, wherein at least one member is formed of the laminated film according to claim 2 .