POROUS POLYTETRAFLUOROETHYLENE FILM AND AIR FILTER FILTRATION MATERIAL

摘要

Provided is a porous polytetrafluoroethylene (PTFE) film which has a PF value of 36 or more and a weight of 0.90 g/m2 or less. In this connection, the PF value is equal to {-log(PT (%)/100)/(PL(Pa)/9.8} × 100. In the formula, PT (permeability) is determined by PT (%) = 100 - CE (%); CE (collection efficiency) is determined by the value that is measured using a dioctylphthalate having a particle diameter of 0.10-0.20 µm at a permeation flow rate of 5.3 cm/second; and PL (pressure loss) is determined by the value that is measured at a permeation flow rate of 5.3 cm/second. This porous PTFE film is suitable as an air filter filtration material.