Method for manufacturing porous membrane and porous membrane
AssigneeFUJIFILM Corporation
InventorAkihiro Ikeyama
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Abstract
The present invention provides a method for manufacturing a porous membrane having high water permeability and hydrophilicity, which is not easily affected by a treatment such as washing, the method including: preparing, as a substrate, a membrane having a plurality of pores, which includes a water-insoluble resin such as polysulfone and a water-soluble resin including a monomer unit of polyvinylpyrrolidone or a monomer unit of polyvinyl alcohol; and irradiating the substrate with an electron beam in the presence of an aqueous solvent to crosslink at least a part of the water-soluble resin.
Claims24
A method for manufacturing a porous membrane, comprising:
- preparing, as a substrate, a membrane having a plurality of pores, which includes a water-insoluble resin and a water-soluble resin including a monomer unit of polyvinylpyrrolidone or a monomer unit of polyvinyl alcohol;
- and
- irradiating the substrate with an electron beam in the presence of an aqueous solvent to crosslink at least a part of the water-soluble resin,
- which further comprises
- in the preparation of the substrate, casting a solution including the water-insoluble resin and the water-soluble resin on a support to form the membrane having a plurality of pores on the support, the membrane having a layered compact portion with a minimum pore diameter inside the membrane,
- wherein a thickness of the substrate is 40 μm or more and the electron beam irradiation is performed at an absorbed dose of 50 kGray or more,
- the water-soluble resin is included in an amount of 0.5% to 10% by mass of the dry mass of the porous membrane, and
- an insoluble component which is a cross-linked water-soluble resin is 1.2% by mass or more of a dry mass of the porous membrane, said mass percentage being obtained by immersing 60 cm2 of the porous membrane in 50 mL of methylene chloride for 24 hours, measuring the mass of the insoluble component and determining the percentage of the insoluble component based on the dry mass of the porous membrane before the immersion.
A porous membrane comprising:
- a water-insoluble resin;
- and
- a water-soluble resin including a monomer unit of polyvinylpyrrolidone or a monomer unit of polyvinyl alcohol,
- wherein an insoluble component which is a cross-linked water-soluble resin is 1.2% by mass or more of a dry mass of the porous membrane, said mass percentage being obtained by immersing 60 cm2 of the porous membrane in 50 mL of methylene chloride for 24 hours, measuring the mass of the insoluble component and determining the percentage of the insoluble component based on the dry mass of the porous membrane before the immersion,
- the water-soluble resin is included in an amount of 0.5% to 10% by mass of the dry mass of the porous membrane,
- the porous membrane has a layered compact portion with a minimum pore diameter inside the membrane, and
- a thickness of the porous membrane is 40 μm or more.
A porous membrane comprising:
- a water-insoluble resin;
- and
- a water-soluble resin including a monomer unit of polyvinylpyrrolidone or a monomer unit of polyvinyl alcohol,
- wherein an insoluble component which is a cross-linked water-soluble resin is 1.2% by mass or more of a dry mass of the porous membrane, said mass percentage being obtained by immersing 60 cm2 of the porous membrane in 50 mL of methylene chloride for 24 hours, measuring the mass of the insoluble component and determining the percentage of the insoluble component based on the dry mass of the porous membrane before the immersion,
- the porous membrane has a layered compact portion with a minimum pore diameter inside the membrane, and
- a thickness of the porous membrane is more than 40 μm.
Dependencies are inferred from the claim text.