US 12,246,292 B2
Micro or nano porous membrane, manufacturing method of same, porous resin membrane complex, and filter element
Hirokazu Katayama, Osaka (JP); Fumihiro Hayashi, Osaka (JP); and Yasuhiro Okuda, Osaka (JP)
Assigned to SUMITOMO ELECTRIC INDUSTRIES, LTD., Osaka (JP)
Appl. No. 17/049,431
Filed by SUMITOMO ELECTRIC INDUSTRIES, LTD., Osaka (JP)
PCT Filed May 8, 2019, PCT No. PCT/JP2019/018340
§ 371(c)(1), (2) Date Oct. 21, 2020,
PCT Pub. No. WO2019/220960, PCT Pub. Date Nov. 21, 2019.
Claims priority of application No. 2018-094025 (JP), filed on May 15, 2018.
Prior Publication US 2021/0260536 A1, Aug. 26, 2021
Int. Cl. B01D 71/36 (2006.01); B01D 67/00 (2006.01); B01D 69/02 (2006.01); B01D 69/10 (2006.01)
CPC B01D 71/36 (2013.01) [B01D 67/00041 (2022.08); B01D 67/0027 (2013.01); B01D 69/02 (2013.01); B01D 69/107 (2022.08); B01D 2323/12 (2013.01); B01D 2325/04 (2013.01); B01D 2325/20 (2013.01); B01D 2325/32 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A micro or nano porous membrane composed of a stretched membrane obtained by stretching a non-porous membrane material of fluororesins,
wherein the non-porous membrane material of the fluororesins is a sintered body obtained by shaping a plurality of core-shell particles containing the fluororesins into a membrane, and by sintering the plurality of core-shell particles by heating the membrane obtained by the shaping to its melting point or more,
wherein the core-shell particles include cores and shells covering outer surfaces of the cores,
wherein an average particle size of the core-shell particles before being sintered is greater than or equal to 100 nm and less than or equal to 1,000 nm,
wherein a ratio of a volume of the shells to a volume of the cores in the core-shell particles before being sintered is greater than or equal to 2/98 and less than or equal to 50/50,
wherein a fluororesin of the cores is a tetrafluoroethylene-hexafluoropropylene copolymer or a combination of the tetrafluoroethylene-hexafluoropropylene copolymer and a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and a fluororesin of the shells is polytetrafluoroethylene,
wherein the tetrafluoroethylene-hexafluoropropylene copolymer does not include any monomer other than tetrafluoroethylene and hexafluoropropylene,
wherein the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer does not include any monomer other than tetrafluoroethylene and perfluoroalkyl vinyl ether,
wherein a first heat of fusion of the fluororesins in the core-shell particles is less than or equal to 68 J/g, and
a Gurley in the micro or nano porous membrane is 25 seconds or less.