A polyolefin microporous membrane is disclosed. The membrane has a width of not less than 100 mm, and a variation range of an F25 value in a width direction is not greater than 1 MPa. The F25 value is a value obtained by dividing a load at 25% elongation of a sample of the laminated polyolefin microporous membrane as measured with a tensile testing machine by a cross-sectional area of the sample.

A multilayer microporous membrane including polymer and having a shutdown temperature of ≦130.5° C. and a storage stability of 0.3V or less.

A multilayer microporous membrane including polymer and having a shutdown temperature of ≦130.5° C. and a storage stability of 0.3V or less.

A method of fabricating a gas separation membrane includes providing a coextruded multilayer film that includes a first polymer layer formed of a first polymer material and a second polymer layer formed of a second polymer material, the first polymer material having a first gas permeability. The coextruded multilayer film is axially oriented such that the second polymer layer has a second gas permeability that is greater than the first gas permeability.

A method of making a nanoporous structure comprising a matrix and at least one nanosized pore within the matrix, wherein the method comprises contacting at least a portion of a templated matrix with an acid solution, wherein the templated matrix comprises a matrix that selected from the group consisting of an organic polymer, a sol-based ceramic, an inorganic salt, an organoaluminate, and combinations thereof, and one or more nanosized templates within the matrix, wherein each nanosized template comprises a core that comprises an inorganic oxide, to dissolve at least a portion of the inorganic oxide of at least one of the cores and form the at least one nanosized pore within the matrix thereby forming the nanoporous structure.

A method of making a nanoporous structure comprising a matrix and at least one nanosized pore within the matrix, wherein the method comprises contacting at least a portion of a templated matrix with an acid solution, wherein the templated matrix comprises a matrix that selected from the group consisting of an organic polymer, a sol-based ceramic, an inorganic salt, an organoaluminate, and combinations thereof, and one or more nanosized templates within the matrix, wherein each nanosized template comprises a core that comprises an inorganic oxide, to dissolve at least a portion of the inorganic oxide of at least one of the cores and form the at least one nanosized pore within the matrix thereby forming the nanoporous structure.

An ion exchange membrane having a structure that an ion exchange resin is filled in spaces of a porous base film, the porous base film has a structure that at least two porous olefin resin layers are laminated with a bonding strength of 100 gf/cm or more to less than 700 gf/cm and a Gurley air permeance of 500 sec/100 ml or less in terms of a 100 μm thick film. In this ion exchange membrane, base film has high air permeability though it has a multi-layer structure that a plurality of porous resin films are bonded together, and therefore a rise in electric resistance caused by the lamination of the base sheets is effectively suppressed.

An ion exchange membrane having a structure that an ion exchange resin is filled in spaces of a porous base film, the porous base film has a structure that at least two porous olefin resin layers are laminated with a bonding strength of 100 gf/cm or more to less than 700 gf/cm and a Gurley air permeance of 500 sec/100 ml or less in terms of a 100 μm thick film. In this ion exchange membrane, base film has high air permeability though it has a multi-layer structure that a plurality of porous resin films are bonded together, and therefore a rise in electric resistance caused by the lamination of the base sheets is effectively suppressed.

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 present invention provides a polyolefin microporous membrane made of a polyolefin resin and an inorganic particle, and the puncture strength of the microporous membrane is 3 N/20 μm or more and the membrane thickness retention ratio in penetration creep is 16% or more, thereby being excellent in safety and long-term reliability, and a separator for a nonaqueous electrolyte battery, and the like can be provided.