Abstract: A composite semipermeable membrane, including: a microporous support layer; and a separation functional layer provided on the microporous support layer, in which the separation functional layer includes a crosslinked wholly aromatic polyamide which is a polycondensation product of a polyfunctional aromatic amine and a polyfunctional aromatic acid chloride and contains amino groups and carboxyl groups, and in positive secondary ions measured on a surface of the separation functional layer by time-of-flight secondary ion mass spectrometry, when (count number of m/z=104.03)/(count number of m/z=108.06) is denoted by a, and a molar ratio (carboxyl group/amino group) of the carboxyl group to the amino group, which is obtained by analyzing the entire separation functional layer by 13C solid state NMR, is denoted by b, the following formulae (1) and (2) are satisfied: a?5.0 (1); and a/b?4.3 (2).

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/m2 and includes a structure represented by the formula 1.

Abstract: The present invention relates to a dialysate regeneration method that reduces a urea concentration of a urea-containing aqueous solution, the method including a reverse osmosis process of obtaining, from the urea-containing aqueous solution, a concentrate having a higher urea concentration and a permeate having a lower urea concentration by using a reverse osmosis membrane element at an operating pressure of 0.5 MPa or more and 2.0 MPa or less, in which the urea concentration of the urea-containing aqueous solution is 0.5 g/L or more, the reverse osmosis membrane element includes a reverse osmosis membrane, and the reverse osmosis membrane has a pore diameter of 7.0 ? or less as measured by a positron annihilation lifetime measurement method.

Abstract: The present invention relates to a composite semipermeable membrane including: a substrate; a porous support layer disposed on the substrate; and a separation functional layer disposed on the porous support layer, in which the separation functional layer includes: a first layer including a crosslinked aromatic polyamide; and a coating layer existing on the first layer and including an aliphatic polyamide including a fluorine atom, 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, and has 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.

Abstract: A novel membrane is provided in which the permeate flow rate is not prone to decrease even when the membrane is used to process seawater with high salt concentration and high heavy metal ion concentration. This composite semipermeable membrane comprises a porous support layer, a separation function layer arranged on the porous support layer, and a coating layer coating the separation function layer, wherein the separation function layer contains a crosslinked polymer amide which is a condensate of polyfunctional aromatic amine and polyfunctional aromatic acid chloride, and the coating layer contains an aliphatic polymer including a polyether moiety and a carbonic acid polymer moiety.

Abstract: A composite semipermeable membrane includes a porous supporting membrane and a separation functional layer, in which, in cross-sections having a length of 2.0 ?m in a membrane surface direction, the average number density of projections in the separation functional layer which have a height of one-fifth or more of the 10-point average surface roughness is 10.0-30.0 projections/?m and the projections have an average height less than 100 nm, and in which a water production rate and a salt rejection are predetermined values or more after an aqueous solution is passed through under certain conditions.

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.

Abstract: A novel membrane is provided in which the permeate flow rate is not prone to decrease even when the membrane is used to process seawater with high salt concentration and high heavy metal ion concentration. This composite semipermeable membrane comprises a porous support layer, a separation function layer arranged on the porous support layer, and a coating layer coating the separation function layer, wherein the separation function layer contains a crosslinked polymer amide which is a condensate of polyfunctional aromatic amine and polyfunctional aromatic acid chloride, and the coating layer contains an aliphatic polymer including a polyether moiety and a carbonic acid polymer moiety.

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.

Abstract: The present invention provides a composite semipermeable membrane which has practicable water permeability and high acid resistance. The present invention relates to a composite semipermeable membrane including a supporting membrane and a separation functional layer disposed on the supporting membrane, in which the separation functional layer includes a crosslinked aromatic polyamide and has a protuberance structure including protrusions and recesses, a proportion in number of protrusions each having a height of 100 nm or larger is 80% or larger in the protrusions of the protuberance structure, and the separation functional layer contains amino groups, carboxy groups, and amide groups and satisfies y/x?0.81, in which x is the molar ratio of carboxy groups/amide groups and y is the molar ratio of amino groups/amide groups.

Abstract: Provided is a composite semipermeable membrane, comprising: a microporous support membrane which comprises a substrate and a porous support, and a polyamide separation functional layer formed on the microporous support membrane, wherein the polyamide has an irreversible heat absorption, which is measured using temperature modulated DSC, of 275 J/g or more at a temperature in the range of ?20 to 150° C. in the first heating process. Provided is a high-performance composite semipermeable membrane having high chemical durability, high water permeation and high rejection.

Abstract: To provide a composite semipermeable membrane capable of maintaining high removal performance even after its supporting membrane has come into contact with an aqueous solution high in salt concentration. A composite semipermeable membrane including: a supporting membrane which includes a substrate and a porous supporting layer; and a separation functional layer provided on the porous supporting layer, in which a strength to peel the porous supporting layer away from the substrate is 1.1 N/25 mm or higher.

Abstract: An object of the present invention is to provide a composite semipermeable membrane which has practical water permeability and removing properties and has a high boron removal ratio even after contact with chlorine. A composite semipermeable membrane of the present invention is a composite semipermeable membrane including a substrate, a porous supporting layer and a separation functional layer, which are superposed in this order, in which the separation functional layer includes a crosslinked fully aromatic polyamide, and the crosslinked fully aromatic polyamide has a molar ratio (amide group content) between a total molar proportion of a polyfunctional amine and a polyfunctional aromatic acid halide and a molar proportion of an amide group of 0.86-1.20.

Abstract: An object of the present invention is to provide a composite semipermeable membrane which has practical water permeability and high alkali resistance. The composite semipermeable membrane of the present invention includes: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer of the supporting membrane, in which the separation functional layer includes a crosslinked fully aromatic polyamide, and when a carboxyl group/amide group molar ratio of the separation functional layer measured by a 13C solid NMR spectroscopy is expressed by x, x is 0.54 or less.

Abstract: An object of the invention is to provide a composite semipermeable membrane which has the high ability to remove substances other than water and high water permeability and which suffers little decrease in performance due to fouling. The invention relates to a composite semipermeable membrane including: a supporting membrane having a substrate and a porous supporting layer disposed on the substrate; and a separation functional layer disposed on the supporting membrane, in which, in any ten sites of cross-sections of the composite semipermeable membrane which have a width of 2.0 ?m in a membrane surface direction, the projections having a height of one-fifth or more of a 10-point average surface roughness of the separation functional layer have a standard deviation of height of 60 nm or less.

Abstract: A composite semipermeable membrane includes a porous supporting membrane and a separation functional layer, in which, in cross-sections having a length of 2.0 ?m in a membrane surface direction, the average number density of projections in the separation functional layer which have a height of one-fifth or more of the 10-point average surface roughness is 10.0-30.0 projections/?m and the projections have an average height less than 100 nm, and in which a water production rate and a salt rejection are predetermined values or more after an aqueous solution is passed through under certain conditions.

Abstract: To provide a composite semipermeable membrane capable of maintaining high removal performance even after its supporting membrane has come into contact with an aqueous solution high in salt concentration. A composite semipermeable membrane including: a supporting membrane which includes a substrate and a porous supporting layer; and a separation functional layer provided on the porous supporting layer, in which a strength to peel the porous supporting layer away from the substrate is 1.1 N/25 mm or higher.

Abstract: A composite semipermeable membrane includes: a supporting membrane having a substrate and a porous supporting layer; and a separation functional layer provided on the supporting membrane, in which, when any 10 cross sections of the composite semipermeable membrane, having a length of 2.0 ?m in a membrane surface direction, are observed using an electron microscope, an average number density of projections on the separation functional layer, which have a height equivalent to or higher than ? of a 10-point average surface roughness of the separation functional layer, is 10.0 pieces/?m or more, in each cross section, and an average height of the projections is 100 nm or more.

Abstract: A composite semipermeable membrane includes a porous support membrane made of a substrate and a porous support layer and a polyamide separation-functional layer disposed on the porous support layer, wherein the zeta potential of the separation-functional layer at pH 6 is ?20 mV or lower, and the zeta potential difference between potentials of the separation-functional layer at pH 10 and pH 3 is 25 mV or smaller, and has high water permeability and high salt rejection performance and high acid/alkali durability.

Abstract: Provided is a composite semipermeable membrane, comprising: a microporous support membrane which comprises a substrate and a porous support, and a polyamide separation functional layer formed on the microporous support membrane, wherein the polyamide has an irreversible heat absorption, which is measured using temperature modulated DSC, of 275 J/g or more at a temperature in the range of ?20 to 150° C. in the first heating process. Provided is a high-performance composite semipermeable membrane having high chemical durability, high water permeation and high rejection.