Provided are: a fouling inhibitor that is capable of effectively inhibiting fouling of porous filtration membranes use as water purification membranes or the like, that has resistance to chemicals, such as alkali used when the membrane is fouled, and that is capable of maintaining such effects sufficiently even after chemical wash; a filtration membrane provided with the inhibitor; and a method for producing the same. The inhibitor contains: (A) a copolymer having a weight average molecular weight of 10000 to 300000 and contains a MPC unit (a1) and a BMA unit (a2), wherein the ratio of (a1) to (a2) ((a1)/(a2)) by mole is 10/90 to 70/30; and (B) PVA having a saponification degree of 72 to 93 mol % and a polymerization degree of 300 to 1000, wherein the ratio of component (A) to component (B) ((A)/(B)) by mass is 25/75 to 75/25.

An object of the present invention is to provide a chemical liquid which has excellent defect inhibition performance and hardly breaks a transfer pipe line that a device for manufacturing the chemical liquid includes at the time of manufacturing the chemical liquid. Another object of the present invention is to provide a chemical liquid storage body, a manufacturing method of a chemical liquid, and a manufacturing method of a chemical liquid storage body. The chemical liquid according to an embodiment of the present invention is a chemical liquid containing an organic solvent and an ion of at least one kind of atom selected from the group consisting of an Fe atom, a Cr atom, a Ni atom, and a Pb atom, in which in a case where the chemical liquid contains one kind of the ion, a content of the metal ion is 0.1 to 100 mass ppt, in a case where the chemical liquid contains two or more kinds of the ions, a content of each of the metal ions is 0.1 to 100 mass ppt, and a charge potential is equal to or lower than 100 mV.

[Problem to be solved] To provide an ion exchange membrane, a method for producing an ion exchange membrane, and an electrolyzer that enable a reduction in electrolytic voltage when subjected to electrolysis.

[Solution] An ion exchange membrane including:

a membrane main body including a fluorine-containing polymer having an ion exchange group; and

a coating layer arranged on at least one face of the membrane main body;

wherein the coating layer includes inorganic particles and a binder,

a mass ratio of the binder to the total mass of the inorganic particles and the binder in the coating layer is more than 0.3 and 0.9 or less, and

a surface roughness of the coating layer is 1.20 m or more.

The present invention provides a semipermeable membrane having enhanced alkaline stability and a method of forming a semipermeable membrane having enhanced alkaline stability, comprising steps of: providing an ultrafiltration (UF) base membrane, immersing said UF membrane in a solution comprising at least one substance selected from the group consisting of a polymer preferably polyethylenimine (PEI), a condensate solution and a mixture thereof, thereby forming reactive moieties upon said UF membrane, and forming at least one first layer upon at least portion of said UF base support membrane by immersing said UF base support membrane of step (b) in a solution comprising at least one ingredient selected from the group consisting of polymer preferably polyethylenimine (PEI), condensate solution and a mixture thereof thereby forming a cross-linked skin on the surface of said base membrane.

A functional polymer membrane of the present invention contains a polymer containing at least a structure represented by the following Formula (I), a method for producing the membrane, and an ion exchange apparatus: ##STR00001##
wherein R.sup.1 and R.sup.2 each represent a hydrogen atom or an alkyl group; R.sup.3 to R.sup.6 each represent a substituent; R.sup.3 to R.sup.6 may be bonded to each other and form a ring; A.sup.1 to A.sup.4 each represent a single bond or a divalent linking group; M.sup.1 represents a hydrogen ion, an organic base ion, or a metal ion; J.sup.1 represents a single bond, O, S, SO.sub.2, CO, CR.sup.8R.sup.9, or an alkenylene group, and R.sup.8 and R.sup.9 each represent a hydrogen atom, an alkyl group, or a halogen atom; and k1, k2, k3, k4, n1, n2, m1, m2, p, and q each represent a particular integer.

The invention is directed to preparation of hollow fiber membrane devices that exhibit improved durability and mechanical strength in air separation operations such as generation of nitrogen enriched air on board aircraft. In particular the invention provides for preparation of hollow fiber membrane modules with terminal tubesheets of superior mechanical properties and improved long term durability in air separation operations.

The present invention relates to a process for preparing an asymmetric integrally skinned membrane for the separation of at least one solute from a solution, comprising the steps of: (a) preparing a polybenzimidazole dope solution comprising: (i) a polybenzimidazole polymer, and (ii) a solvent system for said polybenzimidazole which is water miscible; (b) casting a film of said dope solution onto a support; (c) immersing the film cast on the support into a coagulating medium to form an asymmetric integrally skinned membrane; (d) treating the membrane from step (c) with a cross-linking agent; (e) treating the membrane from step (d) with a cross-link modification agent. Further aspects relate to an asymmetric integrally skinned membrane and uses thereof.

A separation membrane has high strength and low leakage property while maintaining high gas permeability using poly(4-methyl-1-pentene) excellent in chemical resistance and gas permeability. The separation membrane contains poly(4-methyl-1-pentene) as a main component, in which a ratio RA of a rigid amorphous of poly(4-methyl-1-pentene) in the separation membrane is 43% or more and 60% or less, a porosity is 30% or more and 70% or less, and a dense layer is provided on at least one surface.

A method for producing a microstructured air-permeable environmental barrier membrane includes providing a substrate, and structuring a through hole into the substrate, the through hole extending fully through the substrate between two opposite surfaces of the substrate, leaving the through hole uncovered, and depositing one or more nanofibers onto at least one of the two opposite substrate surfaces by applying at least one of an electrospinning or blowspinning method, such that the spun nanofibers combine to a network of nanofibers that forms a free-standing and mechanically compliant nanofibrous membrane covering the previously uncovered through hole.

Provided is a semipermeable membrane having a high chlorine resistance.

The semipermeable membrane is formed of a cellulose ester, the cellulose ester having an optionally substituted benzoyl group.