Provided is a cation exchange membrane having excellent mechanical strength against folding and the like and capable of delivering stable electrolytic performance for a long time, an electrolysis vessel using the cation exchange membrane and a method for producing the cation exchange membrane. A cation exchange membrane 1 at least includes: a membrane body containing a fluorine-based polymer having an ion-exchange group; and two or more reinforcing core materials arranged approximately in parallel within the membrane body. The membrane body is provided with two or more elution holes 12 formed between the reinforcing core materials 10 adjacent to each other. In addition, assuming that a distance between the reinforcing core materials 10 adjacent to each other is represented by a, a distance between the reinforcing core materials 10 and the elution holes 12 adjacent to each other is represented by b, a distance between the elution holes 12 adjacent to each other is represented by c, and the number of the elution holes 12 formed between the reinforcing core materials 10 adjacent to each other is represented by n, then a, b, c, and n satisfying the relationship represented by the following expression (1) or expression (2) are at least present.
b>a/(n+1)(1)
c>a/(n+1)(2)

The invention provides a porous medium comprising (i) a porous support and (ii) a polymer or a salt thereof comprising at least one polymerized monomer (A), optionally at least one polymerized monomer (B), and optionally at least one polymerized monomer (C), wherein monomers (A)-(C) are as defined herein, and wherein the polymer or a salt thereof is crosslinked with a crosslinking agent to form a crosslinked polymer or a salt thereof as a network on the porous support. The invention also provides a method of making the porous medium and a method of using the porous medium.

A battery separator is a microporous membrane. The membrane has a major volume of a thermoplastic polymer and a minor volume of an inert particulate filler. The filler is dispersed throughout the polymer. The membrane exhibits a maximum Z-direction compression of 95% of the original membrane thickness. Alternatively, the battery separator is a microporous membrane having a TMA compression curve with a first substantially horizontal slope between ambient temperature and 125 C., a second substantially horizontal slope at greater than 225 C. The curve of the first slope has a lower % compression than the curve of the second slope. The curve of the second slope is not less than 5% compression. The TMA compression curve is graphed so that the Y-axis represents % compression from original thickness and the X-axis represents temperature.

An object of the present invention is to provide a polymer electrolyte membrane meeting power generation properties and physical durability at the same time and having high durability. A polymer electrolyte membrane comprising a microporous membrane and a fluorine-based polymer electrolyte contained in a pore of the microporous membrane, wherein pore distribution of the microporous membrane has a pore distribution with a center of distribution in a pore diameter range of 0.3 m to 5.0 m, and the fluorine-based polymer electrolyte composition contains a fluorine-based polymer electrolyte (component A) having an ion exchange capacity of 0.5 to 3.0 meq/g.

A process for preparing an ion-exchange membrane having a textured surface profile comprising the steps (i) and (ii): (i) screen-printing a radiation-curable composition onto a membrane in a patterned manner; and (ii) irradiating and thereby curing the printed, radiation-curable composition; wherein the radiation-curable composition has a viscosity of at least 30 Pa.Math.s when measured at a shear rate of 0.1 s.sup.1 at 20 C.

Provided are a polymer electrolyte membrane used in fuel cells, and a method for producing the same, the method including a step of filling a crosslinkable ion conductor in the pores of a porous nanoweb support; and a step of crosslinking the ion conductor filled in the pores of the porous nanoweb support. The method for producing a polymer electrolyte membrane uses a relatively smaller amount of an organic solvent, can ameliorate defects of the support caused by solvent evaporation, and can enhance the impregnability of the ion conductor to the support and the convenience of the process.

Bipolar membranes (BPMs) comprising a cation exchange layer (CEL) and an anion exchange layer (AEL) wherein the colour properties of the CEL are visibly different to the colour properties of the AEL. The CEL and the AEL are easily distinguishable so that a stack of membranes comprising the BPMs can be built fast and without mistakes in layer order.