Multilayer structure and packaging material comprising same

A multilayer structure comprising:

• a hard layer (A) comprising an olefinic polymer including a linear low-density polyethylene polymer or copolymer, wherein the linear low-density polyethylene polymer or copolymer is made by polymerization using a metallocene catalyst,
• either a resin composition layer (B1) or a resin composition layer (B2), and
• an adhesive resin layer (C) comprising maleic anhydride-modified polyethylene, wherein
• the hard layer (A) has a puncture strength of 45 N/mm or more and 100 N/mm or less;
• the resin composition layer (B1) consists of:
• an ethylene-vinyl alcohol copolymer (b1) having a melting point Tm1 of 190° C. or more,
• an ethylene-vinyl alcohol copolymer (b2) having a melting point Tm2 of less than 170° C., and
• at least one optional additive selected from the group consisting of a saturated aliphatic amide;
• an unsaturated aliphatic acid amide;
• a bis-aliphatic acid amide;
• an aliphatic acid metal salt;
• a polyolefin having a molecular weight of about 500 to 10,000;
• an inorganic filler;
• an aliphatic polyol;
• an inorganic oxygen absorber;
• ascorbic acid;
• an aliphatic acid ester of ascorbic acid;
• a metal salt of ascorbic acid;
• hydroquinone;
• gallic acid;
• a polyhydric phenol;
• bis-salicyl aldehyde-imine cobalt;
• tetraethylenepentamine cobalt;
• a cobalt-Schiff base complex;
• a porphyrin;
• a macrocyclic polyamine complex;
• a polyethyleneimine-cobalt complex;
• a terpene compound;
• a reaction product of an amino acid with a hydroxyl-containing reducing substance;
• a triphenylmethyl compound;
• an alkali metal salt of acetic acid;
• an alkali metal salt of propionic acid;
• an alkali metal salt of lauric acid;
• an alkali metal salt of stearic acid;
• an alkali metal salt of oleic acid;
• an alkali metal salt of behenic acid sulfuric acid;
• an alkali metal salt of sulfurous acid;
• an alkali metal salt of carbonic acid;
• an alkali metal salt of boric acid;
• an alkali metal salt of phosphoric acid;
• an alkaline earth metal acetate salt;
• an alkaline earth metal borate salt;
• an alkaline earth metal phosphate salt;
• and an alkaline earth metal hydrogen phosphate salt;
• an ethylene content of the ethylene-vinyl alcohol copolymer (b1) is 18 to 35 mol %;
• an ethylene content of the ethylene-vinyl alcohol copolymer (b2) is 38 to 45 mol %;
• a saponification degree of each of the ethylene-vinyl alcohol copolymer (b1) and the ethylene-vinyl alcohol copolymer (b2) are 99 mol % or more;
• and
• the resin composition layer (B2) is made of a resin comprising a modified ethylene-vinyl alcohol copolymer containing a modifying group having a primary hydroxy group represented by formula (I),
• wherein:
• X represents a methyl group or a group represented by R2—OH;
• R1 and R2 represent independently of each other a single bond, an alkylene group having 1 to 9 carbon atoms or an alkyleneoxy group having 1 to 9 carbon atoms;
• and
• the alkylene group and the alkyleneoxy group optionally contain a hydroxy group, an alkoxy group or a halogen atom.