Heat sealable laminated propylene polymer packaging material
AssigneeToyo Boseki Kabushiki Kaisha
InventorsTsutomu Isaka, Maki Matsuo, Yukinobu Miyazaki
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Abstract
A packaging material having an excellent seal packaging property, which comprises (A) a base layer consisting of a stretched film made of a polymer composition comprising a propylene polymer and (B) a surface layer consisting of a stretched film made of a polymeric mixture comprising a polymer blend provided on at least one surface of said base layer, said polymer blend comprising a copolymer of ethylene and propylene and a copolymer of butene and any other polymerizable monomer having an ethylenic unsaturation in a weight proportion of 5:95 to 95:5.
Claims51
A packaging material having excellent heat seal packaging properties, which comprises (A) a base layer consisting of a stretched film made of a polymer composition comprising (a-1) a propylene polymer and (B) a surface layer consisting of a stretched film made of a polymeric mixture comprising a polymer blend provided on at least one surface of said base layer, said polymer blend comprising (b-1) a copolymer of ethylene and propylene having an ethylene content of 10 to 0.5% by weight and a propylene content of 90 to 99.5% by weight and (b-2) a copolymer of butene and another polymerizable monomer having ethylenic unsaturation having a butene content of 70 to 99% by weight and the other polymerizable monomer content of 30 to 1% by weight, (b-1) and (b-2) being combined in a weight proportion of 5:95 to 95:5;
- the total thickness of (B) being 0.2 to 50% of the total thickness of (A) and (B).
A packaging material having excellent heat seal packaging properties, which comprises (A) a base layer consisting of a stretched film made of a polymer composition comprising (a-1) a propylene polymer and (B) a surface layer consisting of a stretched film made of a polymeric mixture comprising a polymer blend provided on at least one surface of said base layer, said polymer blend comprising (b-1) a copolymer of ethylene and propylene having an ethylene content of 10 to 0.5% by weight and a propylene content of 90 to 99.5% by weight and (b-2) a copolymer of butene and another polymerizable monomer having ethylenic unsaturation having a butene content of 70 to 99% by weight and the other polymerizable monomer content of 30 to 1% by weight, (b-1) and (b-2) being combined in a weight proportion of 82:18 to 95:5;
- the total thickness of (B) being 0.2 to 50% of the total thickness of (A) and (B).
A packaging material having excellent heat seal packaging properties, which comprises (A) a base layer consisting of a stretched film made of a polymer composition comprising (a-1) a propylene polymer and (B) a surface consisting of a stretched film made of a polymeric mixture comprising a polymer blend and a low molecular weight thermoplastic resin in a weight proportion of 75:25 to 97:3 provided on at least one surface of said base layer, said polymer blend comprising (b-1) a copolymer of ethylene and propylene having an ethylene content of 10 to 0.5% by weight and a propylene content of 90 to 99.5% by weight and (b-2) a copolymer of butene and another polymerizable monomer having ethylenic unsaturation having a butene content of 70 to 99% by weight and the other polymerizable monomer content of 30 to 1% by weight, (b-1) and (b-2) being combined in a weight proportion of 5:95 to 95:5;
- the total thickness of (B) being 0.2 to 50% of the total thickness of (A) and (B).
A process for preparing a packaging material having excellent heat seal packaging properties, which comprises stretching an unstretched composite film in the machine direction and then stretching the stretched film in a direction substantially perpendicular to said machine direction, said unstretched composite film comprising (A) a base layer made of a polymer composition comprising (a-1) a propylene polymer and (B) a surface layer made of a polymeric mixture comprising a polymer blend provided on at least one surface of said base layer, said polymer blend comprising (b-1) a copolymer of ethylene and propylene having an ethylene content of 10 to 0.5% by weight and a propylene content of 90 to 99.5% by weight and (b-2) a copolymer of butene and an other polymerizable monomer having ethylenic unsaturation having a butene content of 70 to 99% by weight and the other polymerizable monomer content of 30 to 1% by weight, (b-1) and (b-2) being combined in a weight proportion of 5:95 to 95:5;
- the total thickness of (B) being 0.2 to 50% of the total thickness of (A) and (B).
A process for preparing a packaging material having excellent heat seal packaging properties, which comprises stretching a composite film comprising (A) a base layer consisting of a uniaxially stretched film made of a polymer composition comprising (a-1) a propylene polymer and (B) a surface layer consisting of an unstretched film made of a polymeric mixture comprising a polymer blend provided on at least one surface of said base layer in a direction substantially perpendicular to the direction in which the uniaxially stretched film has been stretched, said polymer blend comprising (b-1) a copolymer of ethylene and propylene having an ethylene content of 10 to 0.5% by weight and a propylene content of 90 to 99.5% by weight and (b-2) a copolymer of butene and another polymerizable monomer having ethylenic unsaturation, having a butene content of 70 to 99% by weight and the other polymerizable monomer content of 30 to 1% by weight, (b-1) and (b-2) being combined in a weight proportion of 5:95 to 95:5;
- the total thickness of (B) being 0.2 to 50% of the total thickness of (A) and (B).
Dependencies are inferred from the claim text.