A method suppresses membrane thickness variation and air resistance variation after a compression at 60° C. or 80° C. Stretching is performed at least twice in at least different axial directions before the extraction of the solvent, and at the same time, at least one of (i) and (ii) is satisfied. (i) The step (c) is a first stretching step of stretching the sheet-shaped product at least once in a sheet transport direction (MD direction) and at least once in a sheet width direction (TD direction) individually, and the MD stretching magnification and the TD stretching magnification in the step (c) satisfy (TD stretching magnification≥MD stretching magnification−2). (ii) The stretching temperature (T1) of a first axial stretching performed firstly in the step (c) and the maximal stretching temperature (T2) of a second stretching performed after the first axial stretching satisfy (T1−T2≥0).

The invention provides a hollow fiber membrane exhibiting a favorable gas permeation performance and an excellent heat resistance in which the generation of pinholes are suppressed, and a hollow fiber membrane module using the same. The hollow fiber membrane comprising a gas permeable nonporous layer; and a porous supporting layer to support the nonporous layer formed of a thermoplastic elastomer having a DSC melting peak temperature of 130° C. or higher and a rupture elongation prescribed in ISO 37 (2010) of 300% or more.

The present invention relates to a bipolar ion exchange sheet and a manufacturing method therefor, the bipolar ion exchange sheet comprising: a cation exchange film comprising a cation adsorption sheet and a cation exchange coating layer formed on one side of the cation adsorption sheet; and an anion exchange film comprising an anion adsorption sheet and an anion exchange coating layer formed on one side of the anion adsorption sheet, wherein the cation exchange film and the anion exchange film are bonded so that the cation exchange coating layer and the anion exchange coating layer face each other.

A composite gas membrane comprising: a) a porous support; b) an activated gutter layer; c) a discriminating layer located on the gutter layer; and d) optionally a protective layer on the discriminating layer; wherein the said layers remain in place when a peeling force of 2.5 N/1.5 cm is applied to the outermost of said layers.

The present invention relates to a porous membrane suitable for use in high pressure filtration method.

The present invention relates to a porous membrane suitable for use in high pressure filtration method.

An embodiment of the present invention provides a polyolefin microporous membrane, including: a first porous layer containing a polyolefin and having a structure including a first rod-shaped crystal extending in one direction and plural first plate-shaped crystals arranged in a separated state and intersecting the first rod-shaped crystal, and a second porous layer containing a polyolefin and having a structure including a second rod-shaped crystal extending in another direction intersecting the one direction and plural second plate-shaped crystals arranged in a separated state and intersecting the second rod-shaped crystal.

The present invention relates to high performance, crosslinked hollow-fibre membranes and a new process for manufacturing the same.

Cation exchange membranes and materials including silica-based ceramics, and associated methods, are provided. In some aspects, cation exchange membranes that include a silica-based ceramic that forms a coating on and/or within a porous support membrane are described. The cation exchange membranes and materials may have certain structural or chemical attributes (e.g., pore size/distribution, chemical functionalization) that, alone or in combination, can result in advantageous performance characteristics in any of a variety of applications for which selective transport of positively charged ions through membranes/materials is desired. In some embodiments, the silica-based ceramic contains relatively small pores (e.g., substantially spherical nanopores) that may contribute to some such advantageous properties. In some embodiments, the cation exchange membrane or material includes sulfonate and/or sulfonic acid groups covalently bound to the silica-based ceramic.

A substrate for a composite membrane includes a microporous polyolefin membrane for carrying a hydrophilic resin compound within the pores of the microporous membrane wherein: the average pore diameter is 1 nm to 50 nm; the porosity is 50% to 78%; the membrane thickness is 1 μm to 12 μm; and, when a mixed solution of ethanol and water (volume ratio 1/2) is dripped onto a surface of the microporous polyolefin membrane which has not undergone hydrophilization treatment, the contact angle θ1 between the droplet and the surface is 0 to 90 degrees 1 second after the dripping, and the contact angle θ2 between the droplet and the surface is 0 to 70 degrees 10 minutes after the dripping, and the rate of change of the contact angle ((θ1−θ2)/θ1×100) is 10 to 50%.