| 摘要 |
<p>It is an object of the present invention to provide polytetrafluoroethylene suitable for forming a porous polytetrafluoroethylene film using a high water-soluble surfactant with high volatility. Polytetrafluoroethylene has non-melt-secondary-processability, standard specific gravity of 2.160 or less, an average primary particle size of 150 nm or more, stress relaxation time of 500 seconds or more, and break strength of 29.7 N or more. The polytetrafluoroethylene is obtainable by emulsion polymerization of tetrafluoroethylene in the presence of a fluorinated surfactant with LogPOW of 3.4 or less.</p> |
