WATER-PROOF SOUND-TRANSMITTING MEMBRANE, METHOD FOR PRODUCTION OF WATER-PROOF SOUND-TRANSMITTING MEMBRANE, AND ELECTRICAL APPLIANCE USING THE MEMBRANE

摘要

A water-proof sound-transmitting membrane 10 includes a polytetrafluoroethylene porous membrane 1 and has a surface density of 1 to 20g/m 2 . The polytetrafluoroethylene porous membrane 1 includes a first porous layer 1a, and a second porous layer 1b stacked on and integrated with the first porous layer 1a by a binding force acting between polytetrafluoroethylene matrices.