WATERPROOF SOUND-TRANSMITTING MEMBRANE AND WATERPROOF SOUND-TRANSMITTING STRUCTURE USING THE SAME

摘要

A waterproof sound-transmitting membrane (10) includes a sound-transmitting region (13c) having a porous polytetrafluoroethylene (PTFE) membrane (11). The porous PTFE membrane (11) has a through-thickness air permeability of 2 cm3/cm2/s or more. Thus, it is possible to provide a waterproof sound-transmitting membrane that is suitable for reducing crackling noise while ensuring waterproofness required for at least daily use. The porous PTFE membrane (11) has a water entry pressure of 3 kPa or more, preferably 20 kPa or more and 50 kPa or less. The waterproof sound-transmitting membrane (10) may include an edge region (13p) having an adhesive layer (12).

主权项

1. A waterproof sound-transmitting membrane comprising a sound-transmitting region comprising a porous membrane of polytetrafluoroethylene, the porous membrane having a through-thickness air permeability of 2 cm3/cm2/s or more as measured by Method A (Frazier method) for air permeability measurement according to JIS L 1096 and a water entry pressure of 3 kPa or more as measured by Method B (high hydraulic pressure method) for waterproofness testing according to JIS L 1092.