Patent ID: 6713165
Filing Date: 2004-03-30
Classification: A61J,A61M,B32B,Y10S,Y10T

Abstract:
A multilayer structure composed of thermoplastic polymers, the structure not exceeding 0.1%, by weight of the total structure, of vinyl chloride polymers and of plasticizers having less than a molecular mass of 1000, said multilayer structure including at least three layers and comprising:a first layer comprising at least 60%, by weight of the total first layer weight, of at least one polyolefin of controllable crystallinity defined as comprising at least 90% by weight of the total weight of said at least one polyolefin, of a compound selected from the group consisting of ethylene, propylene and butene, and having a softening temperature of less than 121Â° C., the first layer having a thickness at least 20% of total thickness of the multilayer structure and the first layer having a modulus of elasticity of less than 350 MPa; a second layer, positioned between the first layer and a third layer, the second layer comprising at least 40%, by weight of the total weight of said second layer, of at least one polyolefin of controllable crystallinity, and having an overall softening temperature of less than 121Â° C.; the third layer comprising at least 50%, by weight of the total weight of said third layer, of at least one polyolefin of controllable crystallinity, and having a thickness of from 5 to 30% of the total thickness of the structure and the third layer having a modulus of elasticity which is less than the modulus of elasticity of the first layer, said third layer being a sealing layer, where, taken as a whole, said third layer exhibits a melting temperature of greater than 121Â° C. and said third layer comprises at least one polymer having a melting temperature less than 121Â° C.