Sealant film, resin composition for sealant and uses of the film
AssigneeMitsui Chemicals, Inc.
InventorNorihide Inoue
Life of this patent
Estimating the term…
Abstract
Disclosed is a sealant film having at least two layers including a base layer (X) and a sealant layer (Y) as essential constituents, the base layer (X) comprising a resin composition (AA) which comprises 50 to 98% by weight of a polyolefin resin (A) and 2 to 50% by weight of a tackifier (B), the sealant layer (Y) comprising a polyolefin resin composition (BB), wherein the polyolefin resin (A) is an ethylene polymer (A1) and/or a propylene polymer (A2). Since the sealant film has an excellent balance between heat-sealing properties and easy peel properties, it does not suffer angel hair (nappy phenomenon) even at a lower sealing strength and has good appearance after peeling. The film can be favorably used for forming a food packaging container.
Claims5
A resin composition (EE) for a sealant, comprising a polyethylene resin (CC) or a polypropylene resin (DD), wherein:
- the polyethylene resin (CC) comprises 30 to 90% by weight of an ethylene polymer (A3) having a melt flow rate (ASTM D 1238, 190° C., load of 2.16 kg) of 0.1 to 50 g/10 min and a density (ASTM D 1505) of 0.850 to 0.960 g/cm3, 5 to 50% by weight of a butene polymer (C) having a melt flow rate (ASTM D 1238, 190° C., load of 2.16 kg) of 0.1 to 25 g/10 min and a density (ASTM D 1505) of 0.880 to 0.925 g/cm3 and 2 to 40% by weight of a tackifier (B) ((A3)+(B)+(C)=100% by weight),
- the polypropylene resin (DD) comprises 30 to 90% by weight of a propylene polymer (A4), 5 to 50% by weight of an ethylene polymer (A5) having a melt flow rate (ASTM D 1238, 190° C., load of 2.16 kg) of 0.1 to 50 g/10 min and density (ASTM D 1505) of 0.850 to 0.960 g/cm3 and 1 to 20% by weight of a tackifier (B) ((A4)+(A5)+(B)=100% by weight), and
- the tackifier (B) has a glass transition temperature of 20 to 140° C. and a number-average molecular weight of 1200 or less.
A laminated film being a laminate comprising:
- a) a sealant film having at least two layers including a base layer (X) and a sealant layer (Y) as essential constituents, said base layer (X) comprising a resin composition (AA) which comprises 50 to 98% by weight of a polyolefin resin (A) and 2 to 50% by weight of a tackifier (B), said sealant layer (Y) comprising a polyolefin resin composition (BB), wherein:
- the polyolefin resin (A) is an ethylene polymer (A1) having a melt flow rate (MFR, ASTM D 1238, 190° C., load of 2.16 kg) of 0.1 to 50 g/10 min and a density (ASTM D 1505) of 0.850 to 0.960 g/cm3 and/or a propylene polymer (A2) having a melt flow rate (MFR, ASTM D 1238, 230° C., load of 2.16 kg) of 1 to 100 g/10 min, and the tackifier (B) has a glass transition temperature of 20 to 140° C. and a number-average molecular weight of 1200 or less;
- or
- b) a sealant comprising a resin composition for a sealant, comprising a polyethylene resin (CC) or a polypropylene resin (DD), wherein:
- the polyethylene resin (CC) comprises 30 to 90% by weight of an ethylene polymer (A3) having a melt flow rate (ASTM D 1238, 190° C., load of 2.16 kg) of 0.1 to) 50 g/10 min and a density (ASTM D 1505) of 0.850 to 0.960 g/cm3, 5 to 50% by weight of a butene polymer (C) having a melt flow rate (ASTM D 1238, 190° C., load of 2.16 kg) of 0.1 to 25 g/10 min and a density (ASTM D 1505) of 0.880 to 0.925 g/cm3 and 2 to 40% by weight of a tackifier (B) ((A3)+(B)+(C)=100% by weight),
- the polypropylene resin (DD) comprises 30 to 90% by weight of a propylene polymer (A4), 5 to 50% by weight of an ethylene polymer (A5) having a melt flow rate (ASTM D 1238, 190° C., load of 2.16 kg) of 0.1 to 50 g/10 min and a density (ASTM D 1505) of 0.850 to 0.960 g/cm3 and 1 to 20% by weight of a tackifier (B) ((A4)+(A5)+(B)=100% by weight), and
- the tackifier (B) has a glass transition temperature of 20 to 140° C. and a number-average molecular weight of 1200 or less and having a thickness of 1 to 100 μm and at least one film (Z) selected from the group consisting of a polyolefin film, a polystyrene film, a polyester film, a polyamide film, a laminated film of polyolefin and a gas barrier resin film, an aluminum foil, a paper and a metallized film, which film (Z) is laminated onto the base layer (X) of the sealant film or the sealant.
Dependencies are inferred from the claim text.