The purpose of the present invention is to provide: a composite semipermeable membrane which has three excellent properties, namely, excellent ionic substance rejecting property, excellent nonionic substance rejecting property and excellent water permeability in a practically balanced manner, and a spiral wound separation membrane element which comprises this composite semipermeable membrane. A composite semipermeable membrane according to the present invention is obtained by forming a skin layer that contains a polyamide-based resin on a surface of a porous support, and is configured such that: the polyamide-based resin is obtained by polymerizing a polyfunctional acid halide component and a polyfunctional amine component; the polyfunctional amine component contains m-phenylenediamine and at least one diamine compound represented by general formula (1); and a ratio (mol %) of a segment (A) derived from m-phenylenediamine and a segment (B) derived from the diamine compound in the polyamide-based resin is 99.9:0.1 to 98:2 (segment (A):segment (B)). ##STR00001##

The purpose of the present invention is to provide: a composite semipermeable membrane which has three excellent properties, namely, excellent ionic substance rejecting property, excellent nonionic substance rejecting property and excellent water permeability in a practically balanced manner, and a spiral wound separation membrane element which comprises this composite semipermeable membrane. A composite semipermeable membrane according to the present invention is obtained by forming a skin layer that contains a polyamide-based resin on a surface of a porous support, and is configured such that: the polyamide-based resin is obtained by polymerizing a polyfunctional acid halide component and a polyfunctional amine component; the polyfunctional amine component contains m-phenylenediamine and at least one diamine compound represented by general formula (1); and a ratio (mol %) of a segment (A) derived from m-phenylenediamine and a segment (B) derived from the diamine compound in the polyamide-based resin is 99.9:0.1 to 98:2 (segment (A):segment (B)). ##STR00001##

The present disclosure provides an ion-exchange membrane that includes a supporting substrate impregnated with an ion-exchange material. The supporting substrate includes an imprinted non-woven layer, and the imprinting includes a plurality of deformations at a surface density of at least 16 per cm.sup.2. The supporting substrate may lack a reinforcing layer. In some examples, the supporting substrate may include only a single layer of the imprinted non-woven fabric.

The present disclosure provides an ion-exchange membrane that includes a supporting substrate impregnated with an ion-exchange material. The supporting substrate includes an imprinted non-woven layer, and the imprinting includes a plurality of deformations at a surface density of at least 16 per cm.sup.2. The supporting substrate may lack a reinforcing layer. In some examples, the supporting substrate may include only a single layer of the imprinted non-woven fabric.

Provided are a polymer having a constituent component represented by formula (I) below, a method for producing the polymer, a diamine compound suitable as a raw material for the polymer, a gas separation membrane haying a gas separation layer including the polymer, and a gas separation module and a gas separation apparatus that have the gas separation membrane.

##STR00001##

In the formula (I), R.sup.A, R.sup.B, and R.sup.C represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a halogen atom. Herein, at least one of R.sup.A, R.sup.B, or R.sup.C represents an alkyl group having 1 to 4 carbon atoms or a halogen atom. The alkyl group having 1 to 4 carbon atoms is not trifluoromethyl and ** represents linking sites.

Provided are certain membranes useful in the filtration of liquids and removal of various contaminants therein. In certain aspects the membranes have as one component a polyamide such as Nylon 11 and/or Nylon 12. Also provided is methodology for manufacturing such membranes and their use in filtration and purification of liquids. Membranes of the disclosure thus prepared exhibit superior acid stability when compared to polyamide membranes prepared from Nylon 6 or Nylon 6,6.

Provided are certain composite membranes useful for removing various impurities from liquids. In certain aspects, the composite membranes comprise a hydrophobic polymer having a polyamide coated thereon, and in other aspects, such composite membranes having certain acrylic polymers coated thereon. The composite membranes are useful in the removal of various impurities in liquids, such as those encountered in industrial and life sciences processes.

Provided are certain composite membranes useful for removing various impurities from liquids. In certain aspects, the composite membranes comprise a hydrophobic polymer having a polyamide coated thereon, and in other aspects, such composite membranes having certain acrylic polymers coated thereon. The composite membranes are useful in the removal of various impurities in liquids, such as those encountered in industrial and life sciences processes.

The present invention relates to a method of manufacturing a high-performance thin film composite (TFC) membrane through a solvent activation process. In the present invention, by using a mixed solvent of a good solvent and a poor solvent as an activating solvent, a conventional polysulfone-based support-based TFC membrane having high water permeance as well as excellent salt rejection may be manufactured.

The present invention relates to a method of manufacturing a high-performance thin film composite (TFC) membrane through a solvent activation process. In the present invention, by using a mixed solvent of a good solvent and a poor solvent as an activating solvent, a conventional polysulfone-based support-based TFC membrane having high water permeance as well as excellent salt rejection may be manufactured.