Composite semipermeable membrane, process of producing the same and method of producing highly pure water using the same
AssigneeToray Industries, Inc.
InventorsToshihiro Ikeda, Yukio Nakagawa, Tadahiro Uemura, Masaru Kurihara
Life of this patent
Estimating the term…
Abstract
A composite semipermeable membrane which has a high electrolytes rejection even when the concentration of the electrolytes in feed water is very low and even if the pH of feed water is not less than 8 is disclosed. The composite semipermeable membrane of the present invention comprises a microporous substrate and a cross-linked polyamide-based ultra-thin membrane laminated on the microporous substrate, the ultra-thin membrane having a covalently bonded quaternary nitrogen atom.
Claims10
A composite semipermeable membrane comprising:
- a microporous substrate;
- and
- a cross-linked polyamide ultra-thin membrane laminated on said microporous substrate, said ultra-thin membrane having covalently bonded quaternary nitrogen atoms.
A method of producing highly pure water, comprising treating raw water by a two stage reverse osmosis system including serially connected two reverse osmosis membrane elements, wherein at least one of said reverse osmosis membrane elements include a composite semipermeable membrane comprising a microporous substrate;
- and a cross-linked polyamide ultra-thin membrane having covalently bonded quaternary nitrogen atoms.
A composite semipermeable membrane comprising:
- a microporous substrate;
- and
- a cross-linked polyamide ultra-thin membrane laminated on said microporous substrate, said ultra-thin membrane having covalently bonded quaternary nitrogen atoms contained in a group selected from ##STR7## a functional group selected from the group consisting of epoxy group, aziridine group, episulfide group, halogenated alklyl group, amino group, carboxylic group, halogenated carbonyl group and hydroxy group.
Dependencies are inferred from the claim text.