US 7,562,778 B2
Composite porous membrane and method for producing the same
Katsuhiko Shinada, Toyohasi (Japan); Kei Murase, Toyohashi (Japan); Teruyuki Yamada, Saeki-gun (Japan); Yuuichi Shirasu, Kyoto (Japan); Masahiko Mizuta, Otake (Japan); and Hiroyuki Fujiki, Saeki-gun (Japan)
Assigned to Mitsubishi Rayon Co., Ltd., Tokyo (Japan)
Filed on Jul. 11, 2007, as Appl. No. 11/826,015.
Application 11/826015 is a continuation of application No. 11/125179, filed on May 10, 2005, granted, now 7,306,105.
Application 11/125179 is a continuation of application No. PCT/JP03/14262, filed on Nov. 10, 2003.
Claims priority of application No. 2002-328085 (JP), filed on Nov. 12, 2002; and application No. 2003-194892 (JP), filed on Jul. 10, 2003.
Prior Publication US 2007/0262017 A1, Nov. 15, 2007
This patent is subject to a terminal disclaimer.
Int. Cl. B01D 69/12 (2006.01); B01D 69/10 (2006.01); B01D 29/00 (2006.01)
U.S. Cl. 210—483  [210/488; 210/489; 210/490; 210/500.21] 4 Claims
 
1. A composite porous membrane comprising a braid and a membrane material, wherein:
the membrane material comprises a first porous layer having an inner surface, an outer surface, and a first thickness, and
a second porous layer having an inner surface, an outer surface, and a second thickness,
wherein the first porous layer is arranged on the outer surface of the braid and the second porous layer is arranged on the first porous layer, the first porous layer including a first dense layer with a thickness less than the first thickness, said first dense layer having an average pore diameter in the range of from 0.2 μm to 1 μm, and
the second porous layer including a second dense layer with a thickness less than the second thickness, said second dense layer having an average pore diameter in a range of from 0.1 μm to 0.8 μm, and the inner surface of the second porous layer has about 1% to about 50% adhesion to the outer surface of the first porous layer,
wherein said membrane has at least one of first and second dense layers located 0.1-50 μm inside from the outer surface of its respective porous layer.