Patent ID: 7507476

Claim:
A multilayered pellet having a core-shell structure, wherein the core of the core-shell structure is made of an ethylene-vinyl alcohol copolymer resin composition (A), and the shell of the core-shell structure is made of an ethylene-vinyl alcohol copolymer resin composition (B), wherein the ethylene-vinyl alcohol copolymer resin composition (A) comprises any on of (i) to (iii): (i) an ethylene-vinyl alcohol copolymer (a) and a modified ethylene-vinyl alcohol copolymer (b); (ii) a modified ethylene-vinyl alcohol copolymer (b); and (iii) an ethylene-vinyl alcohol copolymer (a) and a plasticizer (d), wherein the modified ethylene-vinyl alcohol copolymer (b) is at least one selected from the group consisting of the following compounds (1) to (4): (1) a modified ethylene-vinyl alcohol copolymer (b.1) containing 0.3 to 40 mol % of a unit of Formula (1) and 5 to 55 mol % of an ethylene unit: wherein R 1 , R 2, R 3, and R 4 represent each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms, R 3 and R 4 may be bonded to each other, and R 1 , R 2, R 3 and R 4 may have a hydroxyl group, a carboxyl group, or a halogen atom; (2) a modified ethylene-vinyl alcohol copolymer obtained by reacting an ethylene-vinyl alcohol copolymer (a) and a monovalent epoxy compound (c) having a molecular weight of not greater than 500; (3) a modified ethylene-vinyl alcohol copolymer having an ionizable group at its terminal, wherein the ionizable group is selected from the group consisting of a sulfonic acid group and its salt, a carboxylic acid group and its salt, and an ammonium group; and (4) a modified ethylene-vinyl alcohol copolymer obtained by oxidizing an ethylene-vinyl alcohol copolymer, and wherein a heat sealing temperature (TA) (° C.) of the ethylene-vinyl alcohol copolymer resin composition (A) and a heat sealing temperature (TB) (° C.) of the ethylene-vinyl alcohol copolymer resin composition (B) satisfy Formula (1): 3 ≦TB−TA≦ 100 (1) wherein the heat sealing temperature (TA) is a lower limit of an adhesion temperature at which peel strength is at least 400 g/15 mm, wherein the peel strength is determined by the process of heat-sealing two films, each being made of the ethylene-vinyl alcohol copolymer resin composition (A), at a pressure of 0.98 MPa for 1 second, and conducting T-peel test with a tensile tester at a tensile speed of 250 mm/mm, and wherein the heat sealing temperature (TB) is a lower limit of an adhesion temperature at which peel strength is at least 400 g/15 mm, wherein the peel strength is determined by the process of heat-sealing two films, each being made of the ethylene-vinyl alcohol copolymer resin composition (B), at a pressure 0.98 MPa for 1 second, and conducting T-peel test with a tensile tester at a tensile speed of 250 mm/min.