Laminate film and packaging bag
The present disclosure relates to a laminate film for packaging. A laminate film according to an aspect of the present disclosure includes: a resin substrate having a heat sealing surface that constitutes one outermost surface of the laminate film; a coating layer made of a non-metallic material; and an underlayer disposed between the resin substrate and the coating layer. The resin substrate includes a first layer that is made of olefin copolymer and constitutes the heat sealing surface, and a second layer made of polypropylene, and the first and second layers are laminated and biaxially stretched.
1. A laminate film for packaging, comprising:
a resin substrate having a heat sealing surface that constitutes one outermost surface of the laminate film;
a coating layer made of a non-metallic material; and
an underlayer disposed between the resin substrate and the coating layer,
wherein the resin substrate includes a first layer that is made of olefin copolymer having a melting point on a range of 80 to 120° C. and a thickness in a range of 0.5 to 5 μm and constitutes the heat sealing surface, and a second layer made of polypropylene having a thickness in a range of 15 to 50 μm, and the first and second layers are laminated and biaxially stretched.
2. The laminate film of claim 1 , further comprising an ink layer directly laminated on a surface of the coating layer.
3. The laminate film of claim 1 , further comprising a vapor deposition layer disposed between the underlayer and the coating layer.
4. The laminate film of claim 1 , wherein a tear strength by the Elmendorf method is in a range of 10 to 200 mN.
5. The laminate film of claim 1 , wherein the coating layer has transparency to visible light.
6. The laminate film of claim 1 , wherein the coating layer includes a water-soluble polymer, at least one of silane coupling agent and a hydrolysate thereof, at least one of metal alkoxide and a hydrolysate thereof, and an inorganic layered compound.
7. The laminate film of claim 1 , wherein a lamination strength is in a range of 1.0 to 4.0 N/15 mm.
8. The laminate film of claim 1 , wherein the underlayer includes an organic polymer as a main component.
9. The laminate film of claim 8 , wherein the organic polymer includes at least one selected from polyols, organic silane compounds, aqueous polyurethane resins, and reaction products of the polyols and the organic silane compounds.
10. A packaging bag formed by bonding films, wherein the film includes the laminate film of claim 1 .
11. The laminate film of claim 1 , wherein the olefin copolymer is a propylene copolymer.