Regenerated cellulose porous membrane for porous diffusion and method of manufacturing same

Abstract

A pore diffusion type flat membrane separation apparatus X including a plurality of flat membranes 7 and a plurality of flat plate-like supports 1 arranged alternately with each other, each flat membrane 7 defining a plurality of pores and configured to separate a predetermined dispersed substance contained in a solution by a pore diffusion technique, each flat plate-like support 1 having a flow conduit 2 on one or both faces thereof. A ratio between a spatial volume of the flow conduit 2 and a membrane area of the flat membrane 7 is set from 0.04 to 0.4 cm. The flat plate-like support 1 includes, in at least two positions in a lateral face thereof; water conduits 3 in communication with the flow conduit 2, so that flow directions of the solution in the flow conduits 2 of upper and lower flat plate-like supports 1 across the flat membrane 7 may be substantially same directions. The flat plate-like support 1 and the flat membrane 7 can be assembled with and disassembled from each other.

1 - 23 . (canceled) 
     
     
         24 . A regenerated cellulose porous membrane comprising a regenerated cellulose membrane including a multi-layered structure having an average pore diameter (2rf) ranging from 5 to 500 nm, a membrane thickness (d) ranging from 50 to 500 μm, a porosity (Pr) ranging from 0.6 to 0.9; and a development degree of intermolecular hydrogen bond of 40% or less. 
     
     
         25 . The regenerated cellulose porous membrane according to  claim 24 , wherein the average pore diameter (2fr) is set from 8 to 100 nm, the membrane thickness (d) is set from 100 to 300 μm, and the product of the porosity (Pr) and the membrane thickness (d) is set to 50 μm or more. 
     
     
         26 . The regenerated cellulose porous membrane according to  claim 25 , wherein the product of the porosity (Pr) and the membrane thickness (d) is set to range from 100 μm and 200 μm. 
     
     
         27 . A method of manufacturing a regenerated cellulose porous membrane as defined in  claim 24 , the method comprising the steps of:
 forming a porous membrane by a micro-phase separation technique from a solution of cellulose ester as a cellulose derivative with addition of 1% in weight or more of a metal salt thereto; and   subsequently subjecting the resultant membrane to a saponification treatment with an alkaline aqueous solution having a pH value ranging from 11 to 13 at a temperature of 50° C. or lower.   
     
     
         28 . A method of manufacturing a regenerated cellulose porous membrane as defined in  claim 25 , the method comprising the steps of:
 forming a porous membrane by a micro-phase separation technique from a solution of cellulose acetate as a cellulose derivative with addition of 1% in weight or more of a metal salt thereto; and   subsequently subjecting the resultant membrane to a saponification treatment with an alkaline aqueous solution having a pH value ranging from 11 to 13 at a temperature of 50° C. or lower.   
     
     
         29 . A method of manufacturing the regenerated cellulose porous membrane as defined in  claim 26 , the method comprising the steps of:
 forming a porous membrane by a micro-phase separation through evaporation of a good solvent of a cellulose ester, from a solution of cellulose ester as a cellulose derivative with addition of 1% in weight or more of a metal salt thereto; and   subsequently subjecting the resultant membrane to a saponification treatment with an alkaline aqueous solution having a pH value ranging from 11 to 13 at a temperature of 50° C. or lower.