Composite semi-permeable membrane

Patent metadata

Field	Value
Publication number	US-2023001363-A1
Application number	US-202017772608-A
Country	US
Kind code	A1
Filing date	Oct 30, 2020
Priority date	Oct 31, 2019
Publication date	Jan 5, 2023
Grant date	—

Abstract

The present invention relates to a composite semipermeable membrane including: a support membrane including a base and a porous support layer; and a separation functional layer disposed on the porous support layer and including a crosslinked aromatic polyamide, in which the separation functional layer contains sulfo groups in an amount of 7.0×10 −5 to 5.0×10 −2 g/m 2 and includes a structure represented by the formula 1.

First claim

1 . A composite semipermeable membrane comprising:
a support membrane comprising a base and a porous support layer; and a separation functional layer disposed on the porous support layer and comprising a crosslinked aromatic polyamide, wherein the separation functional layer contains sulfo groups in an amount of 7.0×10 −5 to 5.0×10 −2 g/m 2 and includes a structure represented by the following formula 1:

provided that R 1 is a hydrogen atom or a hydrocarbon having a carbon number of 1-10 and optionally having a substituent, R 2 to R 5 are each a hydrogen atom or a hydrocarbon having a carbon number of 1-10, Ar 1 to Ar 3 are each an aromatic ring having a carbon number of 6-14 and optionally having a substituent, and at least one of R 1 , Ar 1 , Ar 2 , and Ar 3 includes a sulfo group.

2 . The composite semipermeable membrane according to claim 1 , wherein the separation functional layer comprises a pleated thin membrane,
the thin membrane has an average thickness of 10 nm-20 nm, and the separation functional layer has a nitrogen-atom surface density, as determined by Rutherford backscattering spectrometry (RBS), of 4.0×10 20 to 1.2×10 21 atoms/m 2 .

3 . The composite semipermeable membrane according to claim 1 , wherein a compound having a structure represented by the following formula 2 is present in the separation functional layer:

provided that X and Y are each a nitrogen atom, an oxygen atom, or a hydrocarbon, R 6 is a hydrogen atom or a hydrocarbon having a carbon number of 1-10, and R 7 is a hydrocarbon having a carbon number of 2-4.

4 . The composite semipermeable membrane according to claim 1 , wherein R 1 in formula 1 is a hydrocarbon having a carbon number of 1 or 2 and having at least one sulfo group.

5 . The composite semipermeable membrane according to claim 1 , wherein Are in formula 1 is an aromatic ring having a carbon number of 6-14 and having at least one sulfo group.

6 . The composite semipermeable membrane according to claim 1 , wherein the separation functional layer has a value of C/D of 3-10,
provided that, A: number of sulfo-group-derived sulfur atoms determined by X-ray photoelectron spectroscopy (XPS), B: total number of nitrogen atoms determined by XPS, C: A/B determined by examining a surface of the separation functional layer in the composite semipermeable membrane, and D: A/B determined by examining a solid obtained by molding a powder of the separation functional layer extracted from the composite semipermeable membrane.

7 . The composite semipermeable membrane according to claim 1 , wherein the separation functional layer has a zeta potential at pH 3 of −5 mV or lower.

Assignees

• Toray Industries

Inventors

• Yasuda Takaaki
• Adachi Yohei
• Mitsui Shinya
• Shimura Harutoki
• Ogawa Takafumi

Classifications

• B01D69/02

  characterised by their properties · CPC title

• B01D2323/40

  in-situ membrane formation · CPC title

• B01D71/82 Primary

  characterised by the presence of specified groups, e.g. introduced by chemical after-treatment · CPC title

• B01D69/1251

  by interfacial polymerisation · CPC title

• B01D71/56 Primary

  Polyamides, e.g. polyester-amides · CPC title