| 摘要 |
PURPOSE:To obtain the titled porous membrane having excellent permeability and a uniform porous structue by using a mixture of a chlorotrifluoroethylene oligomer and a heat-resistant organic substance other than said substance and having a specified sp value as a heat-resistant organic liquid body. CONSTITUTION:A chlorotrifluoroethylene oligomer and a heat-resistant organic substance such as silicon oil having 5-11 sp value are mixed to obtain a heat- resistant organic liquid body. Then, 30-75vol% said organic liquid body, 10- 50vol% polychlorotrifluoroethylene resin, and 7-42 vol% inorganic fine powder such as finely powdered silica are mixed and kneaded. A membrane is formed from the kneaded material with a melt-moldling method. Subsequently, the organic liquid body is extracted by an organic solvent such as 1,1,1-trichloroethane. Besides, the inorganic fine powder is extracted with an aq. alkaline soln. Consequently, a polychlorotrifluoroethylene porous membrane, having 0.02-1mu mean pore diameter, <=4 ratio of maximum pore diameter to mean pore diameter, and 30-90% porosity, is obtained. |
