Composite semipermeable membrane and composite semipermeable membrane element

Patent metadata

Field	Value
Publication number	US-10960360-B2
Application number	US-201916976198-A
Country	US
Kind code	B2
Filing date	Feb 28, 2019
Priority date	Feb 28, 2018
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

By having a coating layer, this composite semipermeable membrane has fouling resistance easily maintainable before and after contact with acid, and enables stable operation over a long period of time. This composite semipermeable membrane comprises a porous support layer, a separation function layer arranged on the porous support layer, and a coating layer arranged on the separation function layer, wherein the separation function layer contains a crosslinked aromatic polyamide which is a polycondensate of polyfunctional aromatic amines and polyfunctional aromatic acid chloride, and the coating layer contains an aliphatic polymer having the structure (I) in the description.

First claim

The invention claimed is:

1. A composite semipermeable membrane
comprising: a microporous support layer;
a separation functional layer arranged on the microporous support layer; and
a coating layer arranged on the separation functional layer,
wherein the separation functional layer comprises a crosslinked aromatic polyamide which is a polycondensate of a polyfunctional aromatic amine and a polyfunctional aromatic a chloride, and
the coating layer comprises an aliphatic polymer having a structure represented by the following formula (I):

wherein
V is at least one structure selected from the structure group (i) below,
W is at least one structure selected from the structure group (ii) below,
and r is an integer of 2 or more;

wherein, in the structure group (i),
n is an integer of 1 or more and 100 or less,
x and y are integers of 1 or more and 50 or less, and
R refers to a methyl group;

wherein, in the structure group (ii),
at least one of the X substituents is a fluorine atom, and the other remaining X substitutent(s) are a hydrogen atom, and
p and q are integers of 1 or more and 10 or less.

2. The composite semipermeable membrane according to claim 1 ,
wherein an amide bond is formed between the aliphatic polymer and the crosslinked aromatic polyamide.

3. The composite semipermeable membrane according to claim 1 ,
wherein a terminal of the aliphatic polymer is a carboxy group.

4. The composite semipermeable membrane according to claim 1 , which satisfies the following conditions (A), (B), (C), and (D):
(A) intensity of a maximum peak between 3700 cm −1 and 2900 cm −1 is 0.08 or more in a difference spectrum of an infrared absorption (IR) spectrum measured under conditions of 25° C. and a relative humidity of 97% and an IR spectrum measured under conditions of 25° C. and a relative humidity of 3%;
(B) a peak top wave number of the difference spectrum between 3700 cm −1 and 2900 cm −1 is 3400 cm −1 or more and 3550 cm −1 or less;
(C) a peak of C1s has one or more maximum values within a range of 290 eV or more and 295 eV or less in X-ray photoelectron spectroscopy measurement performed by irradiating a coating layer side of the composite semipermeable membrane with X-rays; and
(D) the following formula (1): a+b≥10×(c+d+e) (1) is satisfied, in which a, b, c, d, e are respectively count numbers in the cases of m/z of positive secondary ions=45.03, 59.05, 104.03, 108.07, 135.06 when the coating layer side of the composite semipermeable membrane is measured by using time-of-flight secondary ion mass spectrometry.

5. The composite semipermeable membrane according to claim 4 , wherein a limit depth from the coating layer side is 10 nm or less, at which at least one maximum value of the peak of C1s is detected within a range of 290 eV or more and 295 eV or less in the X-ray photoelectron spectroscopy measurement performed by irradiating the coating layer side of the composite semipermeable membrane with X-rays.

6. The composite semipermeable membrane according to claim 1 , wherein the coating layer has a fold structure comprising a protruding portion and a recessed portion, and a proportion of protruding portions having a height of 100 nm or more among the protruding portions of the fold structure is 80% or more.

7. A composite semipermeable membrane element comprising the composite semipermeable membrane according to claim 1 .

Assignees

• Toray Industries

Inventors

• Shimura Harutoki
• Nishiguchi Yoshiki
• Adachi Yohei
• Tokuyama Takahiro
• Kuraoka Kohei

Classifications

• B01D69/1251 Primary

  by interfacial polymerisation · CPC title

• B01D71/5211

  Polyethylene glycol or polyethyleneoxide · CPC title

• B01D67/00933

  by addition of a layer chemically bonded to the membrane · CPC title

• B01D71/76

  Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74 (rubbers in general B01D71/24) · CPC title

• B01D71/32

  containing fluorine atoms · CPC title