The present invention relates to a bipolar ion exchange membrane and a production method therefor, and provides a bipolar ion exchange membrane comprising a first polar heterogeneous ion exchange membrane and a second polar homogeneous ion exchange membrane stacked on each other, wherein the first polar heterogeneous ion exchange membrane is formed of an ion exchange resin powder and a binder resin that contain a first polar ion exchange group, the second polar homogeneous ion exchange membrane is formed of a matrix resin containing a second polar ion exchange group, and an interface between the first polar heterogeneous ion exchange membrane and the second polar homogeneous ion exchange membrane is a heterogeneous interface.

The present invention relates to a gas separation membrane including: a supporting membrane; and a separation functional layer which is provided on the supporting membrane and includes a crosslinked polyamide obtained by polycondensation of a polyfunctional amine and a polyfunctional acid halide, in which, in the crosslinked polyamide, the number A of terminal amino groups, the number B of terminal carboxy groups, and the number C of amide groups satisfy (A+B)/C≤0.66.

In accordance with at least selected embodiments, a battery separator or separator membrane comprises one or more co-extruded multi-microlayer membranes optionally laminated or adhered to another polymer membrane. The separators described herein may provide improved strength, for example, improved puncture strength, particularly at a certain thickness, and may exhibit improved shutdown and/or a reduced propensity to split.

The present invention provides a spiral membrane element in which the effective membrane area of a composite semi-permeable membrane can be increased and any decrease in rejection rate is less likely to occur. The spiral membrane element includes: a laminate including a permeation-side flow path material, a supply-side flow path material, and a composite semi-permeable membrane having a separation function layer on a surface of a porous support; a perforated central tube around which the laminate is wound; and a sealing member for preventing mixing between the supply-side flow path and a permeation-side flow path, the spiral membrane element being characterized in that the thickness of the porous support of the composite semi-permeable membrane is 80 m to 100 m, the permeation-side flow path material is formed from a tricot knit fabric, and the width of a groove that continues in a straight line is 0.05 mm to 0.40 mm.

Disclosed herein is an improved membrane, separator and/or method for forming a multilayer microporous membrane for use in an improved battery separator, particularly a battery separator for a lithium ion secondary battery. Also disclosed herein is the multilayer microporous membrane formed by this method, which has properties that compete with or exceed those of wet process, coated or uncoated, membranes that are also useable in battery separators. Also disclosed are battery separators comprising the multilayer microporous membrane and batteries, vehicles, or devices comprising the separators. The method may comprise at least the following steps: (1) forming a stretched first non-porous precursor film that has pores due to the stretching of a first non-porous precursor film; (2) separately forming a second stretched non-porous precursor film that has pores due to the stretching of a second non-porous precursor film; and then (3) laminating the stretched first non-porous precursor and the stretched second non-porous precursor.

According to one embodiment, a separator is provided. The separator includes a composite membrane. The composite membrane includes a substrate layer, a first composite layer, and a second composite layer. The first composite layer is located on one surface of the substrate layer. The second composite layer is located on the other surface of the substrate layer. The composite membrane has a coefficient of air permeability of 110.sup.14 m.sup.2 or less. The first composite layer has a first surface and a second surface. The first surface is in contact with the substrate layer. The second surface is located on an opposite side to the first surface. Denseness of a portion including the first surface is lower than denseness of a portion including the second surface in the first composite layer.

A membrane device is presented that can used for a wide range of applications from once-through filtration, crossflow filtration, molecular separation, gas/liquid absorption or reaction, gas dispersion into liquid, and degassing of liquid. The device comprises a thin flat sheet membrane that allows certain fluid or molecules go through while blocking others. The membrane sheet is fixed on a supporting structure with mini channel on two sides of the membrane for respective feed and sweep flows. The membrane sheet is sealed with gaskets with two cover plates that the membrane sheet can be replaced or cleaned. The cover plate provides connection ports to connect the feed fluid to the feed channels on one membrane surface and to connect the sweep fluid to the sweep channels on the other surface of the membrane.

The present invention relates to a layered semipermeable membrane satisfying the conditions below. (A) The maximum peak intensity between 3700 and 2900 cm.sup.1 is 0.08 or greater in the difference spectrum between an IR spectrum measured at 25 C. and 97% relative humidity and an IR spectrum measured at 25 C. and 3% relative humidity. (B) The peak top wavenumber between 3700 and 2900 cm.sup.1 of the aforementioned difference spectrum is 3400 cm.sup.1 to 3550 cm.sup.1. (C) The N1s peak has a maximum value at 401 eV or greater in X-ray photoelectron spectroscopy in which X-rays are radiated to a coat layer.

A polyolefin composite porous membrane includes a first layer and a second layer. The first layer contains a polypropylene (A), a first high-density polyethylene (B) having a melting point of 130 C. or higher, and a second high-density polyethylene (C) having a melting point of 120 C. or higher and lower than 130 C. The second layer contains a polyethylene (D). The first layer and the second layer are integrally laminated with each other.

This application relates to a separator for a rechargeable battery. The separator includes a porous substrate and a coating layer on at least one surface of the porous substrate. The coating layer includes a binder including a fluorine-based binder and a (meth)acryl-based binder, and a filler. The fluorine-based binder includes a first structural unit derived from vinylidene fluoride and a second structural unit derived from at least one monomer of hexafluoropropylene, chlorotrifluoroethylene, trifluoroethylene, ethylene tetrafluoride, and ethylene monomers, and the second structural unit is included in an amount of 10 wt % or less with respect to the fluorine-based binder. The fluorine-based binder includes a first fluorine-based binder having a weight average molecular weight of 800,000 to 1,500,000 and a second fluorine-based binder having a weight average molecular weight of less than or equal to 600,000. The (meth)acryl-based binder has pencil hardness of 5H or higher.