CPC B01D 69/12 (2013.01) [B01D 65/08 (2013.01); B01D 69/02 (2013.01); B01D 69/1071 (2022.08); B01D 69/1251 (2022.08); B01D 71/56 (2013.01); B32B 27/34 (2013.01); B01D 2325/30 (2013.01); B32B 2255/10 (2013.01); B32B 2255/26 (2013.01); B32B 2307/726 (2013.01)] | 6 Claims |
1. A composite semipermeable membrane comprising:
a substrate;
a porous support layer disposed on the substrate; and
a separation functional layer disposed on the porous support layer, wherein the separation functional layer comprises:
a first layer comprising a crosslinked aromatic polyamide that is a polymer of a plurality of polyfunctional aromatic amine groups and a plurality of polyfunctional aromatic acid chloride groups linked by a plurality of amide groups; and
a coating layer existing on the first layer and comprising an aliphatic polyamide that includes a fluorine atom and comprises one or more structures of the following structure group (i):
wherein n is an integer of 100 or smaller, R1 is a hydrogen atom or a methyl group, R2 is an alkylene group having a carbon number of 1 to 3, and R3 is a hydrogen atom or an alkyl group having a carbon number of 1 to 3, and
the composite semipermeable membrane has
a proportion of the number of fluorine atoms to the total number of atoms of all elements of 0.5% or more and 8% or less, as measured by X-ray photoelectron spectrometry conducted by irradiating the composite semipermeable membrane with X rays from a side of the coating layer, and
a ratio (N/O ratio) of the number of nitrogen atoms to the number of oxygen atoms of 0.8 or more and 1.3 or less, as measured by the X-ray photoelectron spectrometry.
|