POROUS POLYTETRAFLUOROETHYLENE MEMBRANE, SEPARATING APPARATUS USING SAME, AND PROCESS FOR THEIR PRODUCTION.

摘要

The radius of the sepg. hollows in the membrane is specified to be 0.01 - 2 microns. The PTFE resin can be TFE homopolymer, a TFE-perfluoroalkylvinylether copolymer, a TFE-hexafluoropropylene copolymer, a TFE-ethylene copolymer or a mixt. of these. It is specified that the polytetrafluoroethylene resin has no fibrilised part but is only composed of an organisation of combined resin particles. Prodn. of membrane comprises i) forming a mixture of a dispersive soln. of PTFE resin and a filament forming polymer into a membrane having hollows or a sheet-shaped membrane. ii) This membrane is heat-treated at the melting temp. of the resin or higher. iii) The filament forming polymer is removed. The dispersion solution of PTFE is specified to be an aqueous solution. The particle size of the resin in the dispersion solution is 1 micron or less. The separating apparatus is made of the porous hollow filament membrane of PTFE seated at the terminals with a fluoride resin such as vinylidene fluoride resin etc. Prodn. of sepg. appts. comprises i), ii), iii) and additionally iv) encasing the membrane and seating it with fluoride resin using a melt-fixing method.