| 摘要 |
<p>The present invention provides a polytetrafluoroethylene (PTFE) porous membrane having, when an arbitrary in-plane direction of the membrane is taken as a first direction, and an in-plane direction orthogonal to the first direction is taken as a second direction, a strength of 20 N/mm 2 or more, an elongation percentage at breakage of 200% or less, and a ratio of the elongation percentage in the second direction with respect to the elongation percentage in the first direction of 0.5 to 2.0, in a tensile test performed in the first direction and in the second direction. The PTFE porous membrane of the present invention is less elongated due to an external force and has small anisotropy in elongation.</p> |
