LIQUID PACKAGING CONTAINER

摘要

Provided is a liquid packaging container having satisfactory flexibility and transparency, high heat-seal strength, high bag-breaking strength at normal temperature and low temperatures, and low (inner layer)-(inner layer) adhesiveness, which are properties important for liquid packaging containers for medical use. Specifically, provided is a liquid packaging container formed from a laminate of at least three layers including an inner layer formed from a resin composition (Y) as described below, an intermediate layer, and an outer layer formed from a resin composition (Z) as described below, the intermediate layer being formed from a resin composition (X) as described below:
resin composition (X): a resin composition including 100 parts by mass of a polypropylene-based resin (1), 5 parts by mass to 95 parts by mass of a particular thermoplastic elastomer (2), and 10 parts by mass to 95 parts by mass of a particular ethylene-α-olefin copolymer (3);resin composition (Y): a resin composition including 100 parts by mass of a polypropylene-based resin (1′), and 5 parts by mass to 250 parts by mass of a particular thermoplastic elastomer (2′) (provided that a particular ethylene-α-olefin copolymer is not included or, if included, the content of the copolymer is less than 10 parts by mass); andresin composition (Z): a resin composition including 100 parts by mass of a polypropylene-based resin (1″), and 0 parts by mass to 35 parts by mass of a particular thermoplastic elastomer (2″).

主权项

1. A liquid packaging container comprising a laminate of at least three layers comprising an inner layer formed from a resin composition (Y); an intermediate layer formed from a resin composition (X); and an outer layer formed from a resin composition (Z):
wherein: the resin composition (X) comprises 100 parts by mass of a polypropylene-based resin (1) having a content of a structural unit derived from a propylene monomer of 60 mol % or more; 5 parts by mass to 95 parts by mass of a thermoplastic elastomer (2) having a number average molecular weight of 20,000 to 500,000, the thermoplastic elastomer (2) being a thermoplastic elastomer obtained by hydrogenating a block copolymer comprising a polymer block (A) which comprises a structural unit derived from an aromatic vinyl compound as a main component and has a number average molecular weight of 2,500 to 100,000, and a polymer block (B) which comprises a structural unit derived from a conjugated diene compound as a main component and has a content of a vinyl bond structural unit of 50 mol % or more and a number average molecular weight of 10,000 to 300,000, the polymer block (B) comprising 80 mol % or more of carbon-carbon double bonds hydrogenated; and 10 parts by mass to 95 parts by mass of an ethylene-α-olefin copolymer (3) having a content of a structural unit derived from an ethylene monomer of 50 mol % to 95 mol %, the resin composition (Y) comprises 100 parts by mass of a polypropylene-based resin (1′) having a content of a structural unit derived from a propylene monomer of 60 mol % or more; and 5 parts by mass to 250 parts by mass of a thermoplastic elastomer (2′) comprising a polymer block which comprises a structural unit derived from an aromatic vinyl compound as a main component and a polymer block which comprises a structural unit derived from a conjugated diene compound as a main component, provided that an ethylene-α-olefin copolymer having a content of a structural unit derived from an ethylene monomer of 50 mol % to 95 mol % is not included or, if included, the content of the copolymer is less than 10 parts by mass, and the resin composition (Z) comprises 100 parts by mass of a polypropylene-based resin (1″) having a content of a structural unit derived from a propylene monomer of 60 mol % or more; and 0 parts by mass to 35 parts by mass of a thermoplastic elastomer (2″) comprising a polymer block which comprises a structural unit derived from an aromatic vinyl compound as a main component and a polymer block which comprises a structural unit derived from a conjugated diene compound as a main component.