Abstract: Disclosed herein is a polymer composition, its manufacture and use, said composition may comprise greater than about 90 mole % propylene monomer, and having a unique combination of properties, including one or more of the following: a heat of fusion of more than about 108 J/g, a melting point of 165° C. or higher, a Melt Flow Rate so low that it is essentially not measurable and a molecular weight of greater than about 1.5×106. Further disclosed herein are blends or mixtures of the present novel polymer composition and products, such as, for example, microporous film structures and the like comprising same.

Abstract: A microporous polyolefin membrane having large pore diameters and excellent air permeability, mechanical strength and compression resistance can be obtained by (a) stretching a gel molding comprising a polyolefin and a membrane-forming solvent at least uniaxially at a temperature from the crystal dispersion temperature of the polyolefin +15° C. to the crystal dispersion temperature of the polyolefin +40° C., removing the membrane-forming solvent, and then stretching again the resultant membrane to 1.1 to 2.5 fold at least uniaxially, or by (b) stretching the gel molding at least uniaxially, bringing the stretched film into contact with a hot solvent before and/or after removing the membrane-forming solvent, and then stretching again the resultant membrane to 1.1 to 2.5 fold at least uniaxially.

Abstract: A method for producing a microporous thermoplastic resin membrane from a thermoplastic resin and a membrane-forming solvent, using as part of a starting material film waste based on the thermoplastic resin and the membrane-forming solvent, which is generated in the production process of the microporous thermoplastic resin membrane, comprising the steps of melt-blending a virgin thermoplastic resin and a membrane-forming solvent in an extruder to prepare a virgin material solution, adding the film waste generated in the same or different production processes to the virgin material solution in a molten state in the extruder at an intermediate point, melt-blending them to prepare a thermoplastic resin solution, extruding the thermoplastic resin solution through a die, cooling the extrudate to form a gel-like sheet, and removing the membrane-forming solvent from the gel-like sheet.

Abstract: The invention relates to a multi-layer, microporous polyolefin membrane having appropriate permeability, pin puncture strength, shutdown temperature, shutdown speed, meltdown temperature, and thickness uniformity. The invention also relates to a battery separator formed by such multi-layer, 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 a multi-layer, microporous membrane having appropriate permeability, pin puncture strength, shutdown temperature, shutdown speed, meltdown temperature, and thickness uniformity. The invention also relates to a battery separator formed by such multi-layer, 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: A multi-layer, microporous polyethylene membrane having at least three layers comprising (a) a first microporous layer amount of a polyethylene resin and constituting at least both surface layers, and (b) at least one second microporous layer made of a polyethylene resin, a heat-resistant resin having a melting point or glass transition temperature of 150° C. or higher and a filler, and sandwiched by both surface layers.

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.

Abstract: The microporous polyolefin membrane obtained by stretching a gel molding comprising a polyolefin and a membrane-forming solvent at least uniaxially, heat-setting it, removing the membrane-forming solvent, and re-stretching it at least uniaxially has a large pore diameter and excellent air permeability, mechanical strength and compression resistance.

Abstract: A method for producing a microporous polyolefin membrane by extruding a melt blend comprising a polyethylene resin, polypropylene having a mass-average molecular weight of 1×105 or more and an ethylene content of 5% by mass or less, and a membrane-forming solvent through a die, slowly cooling the resultant extrudate to form a gel-like sheet, stretching the gel-like sheet, and removing the above membrane-forming solvent, the slow-cooling speed of the extrudate being 30° C./second or less.

Abstract: A coextrusion die for producing a multilayer film or sheet of thermoplastic materials.

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.

Abstract: A microporous polyolefin membrane having excellent compression resistance is obtained by stretching a gel molding comprising a polyolefin and a membrane-forming solvent, removing the membrane-forming solvent, and stretching the resultant membrane again at least uniaxially at a speed of 3%/second or more at a temperature equal to or lower than the crystal dispersion temperature +20° C.

Abstract: Disclosed herein is multi-layer, microporous polyolefin membrane comprising a first porous layer comprising primarily a polyethylene, and a second porous layer comprising a polyethylene resin and polypropylene, the polypropylene having a weight-average molecular weight of 6×105 or more and a heat of fusion (measured by a differential scanning calorimeter) of 90 J/g or more, a fraction of the polypropylene having a molecular weight of 5×104 or less being 5% or less by mass.

Abstract: Disclosed herein is a multi-layer, microporous polyolefin membrane comprising a first porous layer of a polyethylene, and a second porous layer comprising a polyethylene, and polypropylene having a weight-average molecular weight of 6×105 or more and a fraction having a molecular weight of 1.8×106 or more being 10% or more by mass.

Abstract: A microporous polyolefin membrane comprising a polyethylene resin, and polypropylene having a weight-average molecular weight of 6×105 or more and a heat of fusion of 90 J/g or more (measured by a differential scanning calorimeter), a fraction having a molecular weight of 1.8×106 or more being 10% or more by mass of the polypropylene.

Abstract: A microporous polyolefin membrane comprising a polyethylene resin, and polypropylene having a weight-average molecular weight of 6×105 or more and a heat of fusion of 90 J/g or more (measured by a differential scanning calorimeter), a fraction having a molecular weight of 5×104 or less being 5% or less by mass of the polypropylene.

Abstract: A microporous composite membrane obtained by coating at least one surface of a microporous polyolefin membrane with a solution of a gelable fluororesin in a mixed solvent of a good solvent for the fluororesin, and a poor solvent having a dipole moment of 1.8 Debye or less and drying to form a porous coating layer of the above fluororesin has cylindrical penetrating pores formed in the above coating layer, with well-balanced permeability, adhesion to electrodes, mechanical strength, heat shrinkage resistance, shutdown properties and meltdown properties.

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.

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: A microporous polyolefin membrane is formed by fine fibrils, 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 has micropores of 0.05 to 5 &mgr;m in average pore size and crystal lamellas of component (A) or (B) being in a specific orientation state. The membrane is produced by 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.