Patent ID: 9283525
Filing Date: 2016-03-15
CPC Classification: B01D,C08F,C08G,C08J

Claim Text:
1. A porous polymer membrane comprising a fluoropolymer (A) that includes a vinylidene fluoride unit and a tetrafluoroethylene unit, wherein the membrane is a hollow fiber membrane, wherein the fluoropolymer (A) includes the vinylidene fluoride unit and the tetrafluoroethylene unit in a molar ratio of the vinylidene fluoride unit/tetrafluoroethylene unit of 50 to 90/50 to 10; and wherein the porous polymer membrane has a surface that has a ratio of oxygen/fluorine content (0/F) on the surface of not less than 0.050 but not more than 0.118 when measured by X-ray photoelectron spectroscopy (XPS).