Patent ID: 9295931
Filing Date: 2016-03-29
CPC Classification: B01D,B29C,B29K

Claim Text:
1. A porous polytetrafluoroethylene membrane having a PF value of 36 or more and a mass per unit area of 0.90 g/m 2 or less, the PF value being determined by the following equation: where PT is a permeability and is determined by PT (%)=100−CE (%), CE is a collection efficiency and is determined by a value measured using dioctyl phthalate particles with a particle diameter of 0.10 μm to 0.20 μm under a condition of a permeate flow rate of 5.3 cm/sec, and PL is a pressure loss and is determined by a value measured under a condition of a permeate flow rate of 5.3 cm/sec.