MICROPOROUS MEMBRANE,申请号JP19860285997-传众专利搜索

MICROPOROUS MEMBRANE

申请公布号：JPS63141607(A)

申请号：JP19860285997

申请日期：1986.12.02

申请公布日期：1988.06.14

申请人：

FUJI PHOTO FILM CO LTD

发明人：SASAKI JUN;OTANI SUMIO;NARUO KYOICHI

分类号：B01D39/16;B01D71/68;B29C41/12;B29K105/04;B29L7/00;C08J9/28

主分类号：B01D39/16

摘要：PURPOSE:To obtain a title microporous membrane having low filtration resistance, a large filtration flow rate, and a long filtration life by controlling the ratio of the maximum pore diameter to the mean pore diameter in a dense layer to lower than a specified value in an asymmetric membrane having a dense layer in a thickness direction in the membrane. CONSTITUTION:A polymer such as polysulfone is dissolved in a solvent such as N-methyl-2-pyrrolidone, and a swelling agent such as polyvinylpyrrolidone is added to the soln. to prepare a membrane forming soln. The soln. is poured over a glass sheet, the air with controlled temp., relative humidity, and velocity is blown upon the poured liq. film, and the material is immediately dipped in the coagulation bath of water, etc., to obtain a microporous membrane. In this case, the time when to blow the air is adjusted to control the ratio of the maximum pore diameter to the mean pore diameter in the microporous membrane measured by the method according to ASTM-316-80 to <=1.8. By this method, a microporous membrane capable of efficiently collecting fine particles, bacteria, etc., and having a long filtration life is obtained.