Water-vapor-permeable, waterproof, highly elastic films
AssigneeJapan Gore-Tex, Inc.
InventorHaruo Nomi
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Abstract
A water-vapor-permeable, waterproof, highly elastic film of expanded, porous, unsintered polytetrafluoroethylene having impregnated within the pores of the porous film, on both sides thereof, a water-vapor-permeable resin, for example, an elastomer containing urethane bonds and a hydrophilic group(s) in its molecular structure. The film of this invention is useful in clothing, tents, and various applications where water vapor transmission characteristics and waterproofness are simultaneously desired. The film has elongation percentage in at least one direction exceeding 40% and durability in repeated stretching to 80% of its elongation percentage of more than 200,000 cycles.
Claims4
A water-vapor-permeable, gas impermeable, liquid waterproof, highly elastic composite film comprising a film of expanded, porous, unsintered polytetrafluoroethylene having completely impregnated within its pores a water-vapor-permeable polymeric resin, said composite film having elongation percentage in at least one direction exceeding 40% and durability in repeated stretching to 80% of its elongation percentage of more than 200,000 cycles.
Dependencies are inferred from the claim text.