Abstract: A biaxially stretched microporous film includes band-like polyethylene material having a film width of not less than 300 mm wherein distribution of physical properties in the film width direction and the thickness variation is less than 1.00 ?m and air permeability variation is not greater than 50 seconds/100 mL. The polyethylene microporous film has excellent planarity and uniformity of physical properties required when used in a large-area configuration as a separator film of a lithium ion battery for automobiles or consumer electronics.

Abstract: The invention relates to a microporous membrane having a relatively low heat shrinkage values along planar axes of the membrane. The invention also relates to a battery separator formed by such microporous membrane, and a battery comprising such a separator. Another aspect of the invention relates to a method for making the multi-layer, microporous polyolefin membrane, a method for making a battery using such a membrane as a separator, and a method for using such a battery.

Abstract: The invention relates to microporous polymeric membranes suitable for use as battery separator film. The membrane comprises polyethylene, polypropylene, and polymethylpentene. The invention also relates to a method for producing such a membrane, batteries containing such membranes as battery separators, methods for making such batteries, and methods for using such batteries.

Abstract: The invention relates to microporous polymeric membranes suitable for use as battery separator film. The invention also relates to a method for producing such a membrane, batteries containing such membranes as battery separators, methods for making such batteries, and methods for using such batteries.

Abstract: A battery separator includes a porous membrane A with a thickness of less than 10 ?m including a polypropylene resin, and a porous membrane B laminated thereon including a heat resistant resin and inorganic particles or cross-linked polymer particles, wherein the porous membrane A satisfies a specific range of thickness, average pore size, and porosity, and the entire battery separator satisfies a specific range of thickness, peeling strength at the interface between the porous membrane A and the porous membrane B, and difference in air resistance between the entire battery separator and the porous membrane A.

Abstract: The invention relates to a polyolefin composition. The polyolefin composition can be in the form of a multi-layer, microporous polyolefin membrane comprising a first microporous layer containing 7% or less by mass of ultra-high-molecular-weight polyethylene having a weight-average molecular weight of 1×106 or more, and having a structure in which a pore size distribution curve obtained by mercury intrusion porosimetry has at least two peaks, and a second microporous layer containing 8% or more by mass of the ultra-high-molecular-weight polyethylene.

Abstract: The present invention relates to microporous membranes comprising polymer and having well-balanced permeability and heat shrinkage, especially heat shrinkage at elevated temperature. The invention also relates to methods for making such membranes, and the use of such membranes as battery separator film in, e.g., lithium ion secondary batteries.

Abstract: (1) a combination of a microporous layer made of a polyethylene resin and a microporous layer made of polypropylene and a heat-resistant resin having a melting point or a glass transition temperature of 170° C. or higher, or (2) a combination of a microporous layer made of a polyethylene resin and a microporous layer made of polypropylene and inorganic filler having an aspect ratio of 2 or more provides a multi-layer, microporous polyolefin membrane with well-balanced permeability, mechanical strength, heat shrinkage resistance, shutdown properties and meltdown properties.

Abstract: In an apparatus for manufacturing a microporous plastic film roll by conveying a microporous plastic film by conveying rollers and then winding the microporous plastic film in a roll shape while being brought close to a near roller or being brought into contact with a touch roller, a part of the touch roller to be in contact with the plastic film has a Vickers hardness of 100 to 2,000, and the microporous plastic film is conveyed so that a side of the microporous plastic film opposite the side being in contact with the conveying rollers is in a noncontact state in a range being in contact with the conveying rollers.

Abstract: [Object] To provide a polypropylene resin composition for use in the formation of a microporous membrane having excellent heat resistance and strength. [Solution] A polypropylene resin composition for use in the formation of a microporous membrane according to the present invention comprises as an essential component an ultra-high-molecular-weight propylene homopolymer (A) that satisfies the following requirements (1) to (4): (1) the intrinsic viscosity [?] is 7 dl/g or more and less than 25 dl/g; (2) the mesopentad fraction ranges from 90.0% to 99.5%; (3) the melting point ranges from 153° C. to 167° C.; and (4) in an elution temperature-elution volume curve measured by temperature-rising elution fractionation (TREF), the maximum peak has a peak top temperature in the range of 116° C. to 125° C. and a half-width of 7.0° C. or less.

Abstract: The invention relates to a polyolefin composition. The polyolefin composition can be in the form of a multi-layer, microporous polyolefin membrane comprising a first microporous layer containing 7% or less by mass of ultra-high-molecular-weight polyethylene having a weight-average molecular weight of 1×106 or more, and having a structure in which a pore size distribution curve obtained by mercury intrusion porosimetry has at least two peaks, and a second microporous layer containing 8% or more by mass of the ultra-high-molecular-weight polyethylene.

Abstract: A method of producing a microporous membrane includes combining at least a first polyethylene and a first diluent; combining at least a second polyethylene and a second diluent; combining at least a third polyethylene and a third diluent; forming from the combined polyethylenes and diluents a multi-layer extrudate having a first layer containing the first polyethylene, a second layer containing the second polyethylene, and a third layer located between the first and second layers containing the third polyethylene, wherein the extrudate contains polyethylene having a terminal unsaturation ?0.20 per 10,000 carbon atoms in an amount of 4.0 wt. % to 35.0 wt. %; and removing at least a portion of the first, second, and third diluents from the multi-layer extrudate to produce the membrane.

Abstract: A battery separator includes a microporous polyolefin membrane and a modifying porous layer laminated on at least one surface of the microporous polyolefin membrane, wherein the microporous polyolefin membrane comprises a polyethylene resin, and the modifying porous layer is laminated on at least one surface of the microporous polyolefin membrane having (a) a shutdown temperature of 135° C. or lower, (b) a rate of air resistance change of 1×104 sec/100 cc/° C. or more, and (c) a transverse shrinkage rate at 130° C. of 20% or less.

Abstract: The invention relates to microporous membranes having high meltdown temperature, high air permeability, and high puncture strength. The invention also relates to the production of such membranes and the use of such membranes as battery separator film.

Abstract: The invention relates to microporous membranes having high meltdown temperature, low shutdown temperature, and resistance to heat shrinkage at elevated temperature. The membranes can be produced by stretching a sheet comprising polymethylpentene, polyethylene, and diluent, and then removing the diluent. The membranes can be used as battery separator film in, e.g., lithium ion batteries.

Abstract: Embodiments of the present invention generally relate to microporous membrane, methods for making microporous membrane, and the use of microporous membrane as battery separator film. More particularly, the invention relates to a microporous polymeric membrane including a paraxylylene polymer or copolymer, particularly in combination with a polymeric microporous membrane. The paraxylylene polymer or copolymer can be formed on or laminated to the microporous polymeric membrane.

Abstract: A microporous polyethylene membrane made of a polyethylene resin having a ratio (mass-average molecular weight/number-average molecular weight) of 5 to 300 and comprising 1% or more by mass of ultra-high-molecular-weight polyethylene having a mass-average molecular weight of 7×105 or more, the microporous polyethylene membrane comprising (a) a coarse-structure layer having an average pore diameter of more than 0.04 ?m, which is formed on at least one surface, and (b) a dense-structure layer having an average pore diameter of 0.04 ?m or less, an area ratio of the coarse-structure layer to the dense-structure layer in a membrane cross section being 0.1 to 0.8.

Abstract: A multi-layer, microporous polyethylene membrane comprising (a) a first microporous layer made of a polyethylene resin, and (b) a second microporous layer comprising a polyethylene resin, and a heat-resistant polymer having a melting point or a glass transition temperature of 170° C. or higher, the heat-resistant polymer being dispersed in the form of fine particles in the polyethylene resin, and the second microporous layer having pores containing fine particles of the heat-resistant polymer as nuclei from which the cleavage of polyethylene resin fibrils starts, the multi-layer microporous polyethylene membrane having well-balanced shutdown properties, meltdown properties, permeability, mechanical strength, heat shrinkage resistance and compression resistance.

Abstract: The invention relates to a twin screw extruder for preparing a polymeric solution. The extruder includes an elongated housing having an inlet end, an outlet end, an extruder shaft length L and a pair of interconnecting bores disposed within the housing, a pair of elongated extruder shafts, each having an axis of rotation, the pair of elongated extruder shafts disposed within the pair of interconnecting bores and drivable in at least one direction of rotation, a plurality of extruder screw segments positioned along the pair of elongated extruder shafts in a fixed angular relationship therewith, the plurality of extruder screw segments selected to form multiple extruder stages. The invention also relates to a process for extruding a mixture of polymer and diluent.

Abstract: A method of producing a microporous polyethylene film includes blending polyethylene and a membrane-forming solvent, stretching a sheet formed by extrusion through a die by stretching the sheet in the longitudinal direction at a stretching magnification of 1.1 to 2.0 and stretching the sheet simultaneously in the longitudinal direction and the width direction at an area magnification of 4 to 50, and removing the membrane-forming solvent.