| 摘要 |
PURPOSE:To produce the title flat polypropylene porous membrane appropriate for the separation of plasma, by forming a surface layer having almost the same network structure as that on the inside of the porous membrane on the membrane surface, and specifying the mean pore diameter, bubble point, porosity, water permeability, and thickness of the membrane. CONSTITUTION:From 200-600pts.wt. org. filler such as liq. paraffin and 0.1-0.5 pts.wt. crystal nucleus forming agent are added to 100pts.wt. polypropylene, melted, and kneaded. The molten mixture is discharged in the form of a flat membrane from a die, brought into contact with a cooling and solidifying liq. such as polyethylene glycol incompatible with the org. filler and having 0.2-0.7cal/g specific heat capacity, cooled, and solidified. The org. filler is then extracted and removed with an extractant not dissolving polypropylene and dissolving the org. filler. By this process, a flat polypropylene porous membrane having 0.1-0.5mum mean pore diameter, <=2.0kgf/cm<2> bubble point, 60-80% porosity, >=100ml/min.mmHg.m<2> water permeability, and 30-300mum thickness is obtained.
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