Medical multilayer film structure

The present invention provides a coextruded multilayer thermoplastic film structure for use in forming a medical fluid container such as an I.V. bag. A coextruded multilayer thermoplastic film structure according to the invention includes at least three layers. The first layer (A), which is the layer that contacts medical fluids such as, for example, saline solutions, lactated Ringers solutions, and the like, includes a mixture of a major part of a homopolymer or copolymer of polypropylene and a minor part of a block polymer of a vinyl aromatic monomer and a conjugated diene, a partially hydrogenated derivative thereof, or a selectively hydrogenated derivative thereof to which has been grafted a unsaturated carboxylic reagent. The second layer (B), which is melt bonded to the first layer (A), includes a block polymer of a vinyl aromatic monomer and a conjugated diene, a partially hydrogenated derivative thereof, or a selectively hydrogenated derivative thereof to which has been grafted a unsaturated carboxylic reagent. The third layer (C), which is melt bonded to the second layer (B), includes a homopolymer or copolymer of polypropylene.