Porous film of vinylidene fluoride resin and method for producing same
AssigneeKureha Corporation
InventorsTakumi Katsurao, Tomoaki Kawakami, Toshio Hosokawa
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Abstract
A porous membrane of vinylidene fluoride resin excellent in hydrophilicity and having a good balance among strength, elongation and water permeation rate, which is thus useful as a microfiltration membrane or a separator of battery. The porous membrane is formed from a copolymer of 100 mols of a vinylidene fluoride monomer and 0.01-10.0 mols of a hydrophilic monomer having at least one species of hydrophilic group selected from epoxy group, hydroxy group, carboxy group, ester group, amide group and acid anhydride group.
Claims12
A porous membrane of vinylidene fluoride resin, comprising:
- a copolymer of 100 mols of a vinylidene fluoride monomer and 0.01-10.0 mols of a hydrophilic monomer having at least one species of hydrophilic group selected from epoxy group, hydroxy group, carboxy group, ester group, amide group and acid anhydride group.
A process for producing a porous membrane of vinylidene fluoride resin comprising:
- mixing 100 wt. parts of a vinylidene fluoride resin including a copolymer of 100 mols of a vinylidene fluoride monomer and 0.01-10.0 mols of a hydrophilic monomer having at least one species of hydrophilic group selected from epoxy group, hydroxy group, carboxy group, ester group, amide group and acid anhydride group with 70-250 wt. parts of a plasticizer and 5-80 wt. parts of a good solvent for the copolymer to provide a composition;
- melt-extruding the composition into a film;
- cooling the film preferentially one side thereof to solidify the film;
- extracting the plasticizer;
- and further stretching the film.
Dependencies are inferred from the claim text.