Patent ID: 8695812
Filing Date: 2014-04-15
Classification: B29C,B29K,B29L,B32B,C08J

Abstract:
1. A water-proof sound-transmitting membrane comprising a polytetrafluoroethylene porous membrane, wherein the polytetrafluoroethylene porous membrane includes a first porous layer and a second porous layer, each of the first and second porous layers including a polytetrafluoroethylene matrix, the second porous layer being stacked on and integrated with the first porous layer by a binding force acting between the polytetrafluoroethylene matrices, the water-proof sound-transmitting membrane has a surface density of 2 to 10 g/m the first porous layer and the second porous layer have an average pore size of 1 μm or less, respectively, and the polytetrafluoroethylene porous membrane shows no peripheral leakage within 30 minutes when the polytetrafluoroethylene porous membrane is subjected to a water pressure of 150 kPa.