Abstract: A multi-layer, microporous polyolefin membrane comprising first microporous layers constituting at least both surface layers, and at least one second microporous layer disposed between both surface layers, the first microporous layer comprising a first polyethylene resin containing 8% or more by mass of ultra-high-molecular-weight polyethylene having a weight-average molecular weight of 1×106 or more, the second microporous layer comprising a second polyethylene resin containing 7% or less by mass of the ultra-high-molecular-weight polyethylene, and having a structure in which a pore diameter distribution curve obtained by mercury intrusion porosimetry has at least two peaks, and the total thickness of the first microporous layers being 15-60% per 100% of the total thickness of the first and second microporous layers.

Abstract: A microporous membrane having a structure in which its pore size distribution curve obtained by mercury intrusion porosimetry has at least two peaks, which is produced by extruding a combination of a diluent or solvent and a polyolefin resin composition comprising from about 75 to about 99% of a polyethylene resin having a weight average molecular weight of from about 2.

Abstract: A multi-layer, microporous polyolefin membrane comprising first microporous layers constituting at least both surface layers, and at least one second microporous layer disposed between both surface layers, the first microporous layer comprising a first polyethylene resin containing 8% or more by mass of ultra-high-molecular-weight polyethylene having a weight-average molecular weight of 1×106 or more, the second microporous layer comprising a second polyethylene resin containing 7% or less by mass of the ultra-high-molecular-weight polyethylene, and having a structure in which a pore diameter distribution curve obtained by mercury intrusion porosimetry has at least two peaks, and the total thickness of the first microporous layers being 15-60% per 100% of the total thickness of the first and second microporous layers.

Abstract: The invention relates to microporous membranes comprising first and second components, the first component being polymer and the second component being aliphatic paraffin having a backbone and pendent groups. The invention also relates to methods for making such membranes, and the use of such membranes, e.g., as battery separator film.

Abstract: A thermoplastic film including a microporous polymeric membrane; and a non-woven web bonded to the polymeric microporous membrane, wherein the web comprises a plurality of fibers comprising polyolefin having a Tm?85.0° C. and a Te-Tm?10.0° C.

Abstract: A method for producing a microporous polyolefin membrane formed by fine fibrils, the membrane comprising (A) a polyolefin having a weight-average molecular weight of 5×105 or more or (B) a composition containing Component (A), connected to each other, and having micropores of 0.05 to 5 ?m in average pore size and crystal lamellas of Component (A) or (B) being in a specific alignment state. The method includes extruding a solution of Component (A) or (B) in a solvent into a gel-like formed article; thermally setting the article, with or without stretching, at least at the crystal dispersion temperature of Component (A) or (B), but at melting point of Component (A) or (B) plus 30° C. or lower; and removing the solvent.

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

Abstract: A microporous polyolefin membrane having a structure in which its pore size distribution curve obtained by mercury intrusion porosimetry has at least two peaks, which is produced by (1) extruding a melt-blend of (a) (i) a polyethylene resin containing 7% or less by mass of ultra-high-molecular-weight polyethylene having a weight-average molecular weight of 1×106 or more, or (ii) a mixture of 75% by mass or more of said polyethylene resin and 25% or less by mass of polypropylene, and (b) a membrane-forming solvent, (2) stretching a gel-like sheet obtained by cooling an extrudate, (3) washing it, (4) stretching the resultant microporous membrane to 1.1-1.8 fold in at least one direction, and (5) heat-setting it at a temperature in a range of the stretching temperature of the microporous membrane plus or minus 5 degrees centigrade.

Abstract: A microporous membrane having a structure in which its pore size distribution curve obtained by mercury intrusion porosimetry has at least two peaks, which is produced by extruding a combination of a diluent or solvent and a polyolefin resin composition comprising (a) from about 74 to about 99% of a first polyethylene resin having a weight average molecular weight of from about 2.5×105 to about 5×105 and a molecular weight distribution of from about 5 to about 100, (b) from about 1 to about 5% of a second polyethylene resin having a weight average molecular weight of from about 5×105 to about 1×106 and a molecular weight distribution of from about 5 to about 100, and (c) from 0 to about 25% of a polypropylene resin having a weight average molecular weight of from about 3×105 to about 1.

Abstract: A membrane includes a first polyethylene having an Mw<1.0×106, a second polyethylene having an Mw?1.0×106, and a polypropylene having an Mw?5.0×105 and a ?Hm 80.0 J/g; wherein (a) the sum of the amounts of (i) polypropylene having an Mw?5.0×105 and a ?Hm 80.0 J/g, and (ii) the second polyethylene is?15.0 wt. %, the weight percents being based on the total weight of the polymer in the membrane; (b) the membrane has a thickness?12.0 ?m; and (c) the membrane is microporous.

Abstract: A layered microporous polymeric membrane includes a first blend region having a thickness T1, a third blend region having a thickness T3, and a second blend region located between the first and third blend regions and having a thickness T2, wherein [(T1?T2)/T1]?0.05 and [(T3?T2)/T3]?0.05.

Abstract: A microporous polyethylene membrane having well-balanced permeability, mechanical properties, heat shrinkage resistance, compression resistance, electrolytic solution absorbability, shutdown properties and meltdown properties, with an average pore diameter changing in a thickness direction is produced by melt-blending a polyethylene resin and a membrane-forming solvent to prepare a solution A having a resin concentration of 25 to 50% by mass and a solution B having a resin concentration of 10 to 30% by mass, the resin concentration in the solution A being higher than that in the solution B, (a) simultaneously extruding the resin solutions A and B through a die, cooling the resultant extrudate to provide a gel-like sheet in which the resin solutions A and B are laminated, and removing the membrane-forming solvent from the gel-like sheet, or (b) extruding the resin solutions A and B through separate dies, removing the membrane-forming solvent from the resultant gel-like sheets A and B to form microporous polyet

Abstract: A multi-layer, microporous polyethylene membrane having at least two layers, which comprises (a) a microporous polyethylene resin layer A comprising high-density polyethylene A having 0.2 or more terminal vinyl groups per 10,000 carbon atoms when measured by infrared spectroscopy, and (b) a microporous polyethylene resin layer B comprising high-density polyethylene B having less than 0.2 terminal vinyl groups per 10,000 carbon atoms when measured by infrared spectroscopy, has well-balanced permeability, mechanical strength, heat shrinkage resistance, shutdown properties, meltdown properties and oxidation resistance.

Abstract: An extruder for preparing a polymer-diluent mixture.

Abstract: The invention generally relates to an extruder for preparing a mixture of polymer and diluent. The extruder includes multiple extruder stages, the multiple extruder stages comprising an inlet stage, a dispersion stage, and at least one mixing stage comprising a reverse mixing screw segment having a helical flight that traverses and forms an outer periphery thereof, the helical flight having a plurality of notches positioned therealong. A process for extruding the polymer-diluent mixture is also provided.

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: The invention relates to a microporous membrane having an improved balance of important properties such as melt down temperature and thickness fluctuations. The invention also relates to a system and method for producing such a membrane, the use of such a membrane as a battery separator film, batteries containing such a membrane, and the use of such batteries as a power source in, e.g., electric and hybrid electric vehicles.

Abstract: The invention relates to polyolefin membranes and membrane precursors comprising polyethylene and polypropylene. The polyolefin membrane can be a microporous polyolefin membrane comprising a first microporous layer and at least one second microporous layers where the first and second layers contain polypropylene and polyethylene, and the amount of polyethylene in the first layer is at least about 80 wt. % and the amount of polyethylene in the second layer is at least about 50 wt. %. The amount of polyethylene is higher in the first microporous layer than in the second microporous layer, and the total amount of the polyethylene in the first and second microporous layers is at least about 61 wt. %, based on the weight of the multi-layer, microporous polyolefin membrane.

Abstract: The present invention provides a microporous polyolefin membrane of high permeability and novel structure, and also provides a method of producing the same, wherein its average pore size is gradually decreases from at least one membrane surface towards its center. The method of producing the microporous polyolefin membrane comprises the steps of extruding the solution, composed of 10 to 50 weight % of (A) a polyolefin having a weight-average molecular weight of 5×105 or more or (B) a composition containing this polyolefin and 50 to 90 weight % of a solvent, into a gel-like formed article and removing the solvent therefrom, wherein a treatment step with a hot solvent is incorporated.