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 is a membrane having an average fibril length of 50 μm or more, having an average node length 5 or more times larger than the average fibril length, and having an average node area ratio of 5% or less. 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.