POROUS POLYTETRAFLUOROETHYLENE MEMBRANE, AND WATERPROOF AIR-PERMEABLE MEMBRANE AND WATERPROOF AIR-PERMEABLE MEMBER INCLUDING THE SAME

摘要

A porous polytetrafluoroethylene (PTFE) membrane of the present disclosure has a water vapor permeability, as measured according to Japanese Industrial Standard (JIS) L 1099 (method B-1), of 150000 g/(m²·day) or more in a thickness direction of the membrane. The porous PTFE membrane of the present disclosure, when attached as a waterproof air-permeable membrane to a housing of an electrical component or electrical device, allows water vapor residing inside the housing to be quickly discharged out of the housing.