| 摘要 |
A microporous membrane which has a highly homogenous structure and is excellent in fluid permeation properties, the properties of separating fine particles from a fluid, and mechanical properties. It is prepared by a process for preparing the same, characterized by dissolving an olefin polymer or a mixture thereof with a block or graft copolymer having an olefin chain portion, a hydrogenated butadiene chain portion, or a hydrogenated isoprene chain portion and styrene, methyl methacrylate, vinyl acetate, or vinyl chloride units homogeneously in a particular solvent to prepare a one-phase solution, cooling the solution, at a satisfactory cooling rate to form a gel film having a percolation structure created by liquid-liquid separation, and stretching the same at a low stretching ratio before or after the extraction of the solvent. The microporous membrane thus prepared has a homogenous structure and possesses satisfactory mechanical properties and excellent liquid permeation and fine particle separation properties. |
