| 摘要 |
<p>Provided is a method of makinga stretched, multilayer breathable film having the combination of properties of: (i) providing a barrier to microorganisms; and (ii) providing a barrier to blood and bodily fluids; said method comprising the steps of: (a) simultaneously extruding at least a five-layer film from a die, said five-layer film having as a minimum the following structure: C:A:B:A:C; where B comprises a microporous core layer containing at least one thremoplastic polymer and at least one particulate filler; C comprises an outer monolithic layer containing a hydrophilic polymeric resin capable of absorbing and desorbing moisture and providing a barrier to aqueous fluids and microorganisms, said C layer being substantially free of particulate filler; and A comprises a microporous adhesive layer for bonding said C layers to said core layer B, wherein said C layer sustantially prevents the buildup of particulate filler material on said die during said extrusion step; (b) stretching said extruded five-layer film to thereby form micropores in said microporous core layer and said microporous adhesive layer, wherein said stretching step is conducted and said microporous core layer and said microporous adhesive layers have been formulated so as to provide micropores which allow the passage of gaseous water but substantially prevent the passage of liquid water. The invention also relates to a multilayer film.</p> |
