Composite semipermeable membrane, and production process thereof
AssigneeToray Industries, Inc.
InventorsHiroki Tomioka, Kazuya Sugita, Katsufumi Oto
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Abstract
A composite semipermeable membrane which satisfies the following relationship when seawater at 25° C. having a pH of 6.5, a boron concentration of 5 ppm and a TDS concentration of 3.5% by weight is permeated under an operation pressure of 5.5 MPa: Boron removal ratio (%)≧95−4×membrane permeation flow rate (m3/m2·day).
Claims14
A composite semipermeable membrane which satisfies the following relationship when seawater at 25° C. having a pH of 6.5, a boron concentration of 5 ppm and a TDS concentration of 3.5 by weight is permeated under an operation pressure of 5.5 Mpa:
- Boron removal ratio (%)≧95−4×membrane permeation flow rate (m3/m2·day);
- wherein:
- the composite semipermeable membrane comprises a separating functional layer comprising polyamide formed on a porous substrate film, the polyamide comprising crosslinked polyamide formed by means of interfacial polycondensation by contacting, on the porous substrate film:
- (a) an aqueous solution comprising polyfunctional amine,
- (b) an organic solvent solution comprising polyfunctional acid halide, and
- (c) an organic solvent solution comprising aliphatic acid halide, which is different from the polyfunctional acid halide and has 1 to 4 carbon atom(s);
- wherein the aliphatic acid halide is at least one selected from the group consisting of methanesulfonyl chloride, acetyl chloride, propionyl chloride, butyryl chloride, oxalyl chloride, malonic acid dichloride, succinic acid dichloride, maleic acid dichloride, fumaric acid dichloride, chlorosulfonylacetyl chloride, and N,N-dimethylaminocarbonyl chloride.
A composite semipermeable membrane which satisfies the following relationship when seawater at 25° C. having a pH of 6.5, a boron concentration of 5 ppm and a TDS concentration of 3.5% by weight is permeated under an operation pressure of 5.5 MPa:
- Boron removal ratio (%)≧95−4×membrane permeation flow rate (m3/m2·day);
- wherein:
- the composite semipermeable membrane comprises a separating functional layer comprising polyamide formed on a porous substrate film, the polyamide comprising crosslinked polyamide formed by means of interfacial polycondensation by contacting, on the porous substrate film:
- (a) an aqueous solution comprising polyfunctional amine with
- (b) an organic solvent solution comprising polyfunctional acid halide and aliphatic acid halide which is different from the polyfunctional acid halide and has 1 to 4 carbon atom(s);
- wherein the aliphatic acid halide is at least one selected from the group consisting of methanesulfonyl chloride, acetyl chloride, propionyl chloride, butyryl chloride, oxalyl chloride, malonic acid dichloride, succinic acid dichloride, maleic acid dichloride, fumaric acid dichloride, chlorosulfonylacetyl chloride, and N,N-dimethylaminocarbonyl chloride.
Dependencies are inferred from the claim text.