VINYLIDENE FLUORIDE RESIN HOLLOW FIBER POROUS MEMBRANE AND METHOD FOR PRODUCTION THEREOF

Title:

VINYLIDENE FLUORIDE RESIN HOLLOW FIBER POROUS MEMBRANE AND METHOD FOR PRODUCTION THEREOF

Document Type and Number:

WIPO Patent Application WO/2007/032331

Kind Code:

A1

Abstract:

Disclosed is a vinylidene fluoride resin follow fiber porous membrane which has a micropore (A) having a pore size (average pore size) appropriate for the treatment of (filtered) water and a more uniform pore size distribution, has a good microparticle (bacterium)-blocking efficiency through the micropore, and has a large transmissibility (B). The membrane comprises a vinylidene fluoride resin porous membrane in the form of a follow fiber and has the following characteristics (A) and (B): [Pmax(1m)/Pm], which is the ratio of the maximum pore size (Pmax(1m)) as determined by the bubble point method at the length of 1 m to the average pore size (Pm) as determined by the half-dry method (Pm = 0.05 to 0.20 μm), is 4.0 or less; and (B) [F(L=200 mm, v=70%)/Pm2], which is the ratio of the converted value (F)(L=200 mm, v=70%)(m/day) in terms of void content (v=70%) of the transmissibility as measured under the conditions of difference in pressure of 100 kPa and water temperature of 25ºC at the length (L) of 200 mm to the square value (Pm2) of the average pore size (Pm) (μm), is 3000 (m/day·μm2) or higher. The membrane can be produced by a method comprising the step of subjecting a stretched vinylidene fluoride resin hollow fiber porous membrane to a relaxation process comprising at least two stages in a non-wet atmosphere.

Inventors:

TAKAHASHI TAKEO
TADA YASUHIRO
SUZUKI KENICHI
HINO MASAYUKI
MIZUNO TOSHIYA

Application Number:

PCT/JP2006/318028

Publication Date:

March 22, 2007

Filing Date:

September 12, 2006

Export Citation:

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Assignee:

KUREHA CORP (JP)
TAKAHASHI TAKEO
TADA YASUHIRO
SUZUKI KENICHI
HINO MASAYUKI
MIZUNO TOSHIYA

International Classes:

B01D71/34; B01D69/08; D01D5/247; D01F6/12

Domestic Patent References:

WO2002070115A1	2002-09-12
WO2005032700A1	2005-04-14
WO2004081109A1	2004-09-23

Foreign References:

JP2006063095A	2006-03-09
JP2003041450A	2003-02-13
JP2003210954A	2003-07-29
JPH02263845A	1990-10-26

Other References: