Abstract: A microporous polyolefin battery separator membrane is extremely high in porosity, high in puncture strength, very low in shrinkage and with shutdown temperature of 130-140 degrees C. and melt integrity greater than 165 degrees C. It is made of UHMWPE having a weight-average molecular weight of 1×106 or more and an inert filler. A second microporous polyolefin battery separator has a shutdown temperature of between 95 and 110 degrees C. and a melt integrity of more than 165 degrees C. It is made from an UHMWPE having a weight-average molecular weight of 1×106 or more, a shutdown (LMWPE) having a weight-average molecular weight of 4500 or less and an inert filler. Both membranes have a thickness of 5-75 microns, a porosity of 30-95%, an air permeability of 1-200 sec/10 cc, an average pore diameter of 0.001 to 1 micron and puncture strength of more than 300 grams/25 ?m.

Abstract: A microporous polyolefin battery separator membrane is extremely high in porosity, high in puncture strength, very low in shrinkage and with shutdown temperature of 130-140 degrees C. and melt integrity greater than 165 degrees C. It is made of UHMWPE having a weight-average molecular weight of 1×106 or more and an inert filler. A second microporous polyolefin battery separator has a shutdown temperature of between 95 and 110 degrees C. and a melt integrity of more than 165 degrees C. It is made from an UHMWPE having a weight-average molecular weight of 1×106 or more, a shutdown (LMWPE) having a weight-average molecular weight of 4500 or less and an inert filler. Both membranes have a thickness of 5-75 microns, a porosity of 30-95%, an air permeability of 1-200 sec/10 cc, an average pore diameter of 0.001 to 1 micron and puncture strength of more than 300 grams/25 ?m.

Abstract: A microporous polyolefin battery separator membrane is extremely high in porosity, high in puncture strength, very low in shrinkage and with shutdown temperature of 130–140 degrees C. and melt integrity greater than 165 degrees C. It is made of UHMWPE having a weight-average molecular weight of 1×106 or more and an inert filler. A second microporous polyolefin battery separator has a shutdown temperature of between 95 and 110 degrees C. and a melt integrity of more than 165 degrees C. It is made from an UHMWPE having a weight-average molecular weight of 1×106 or more, a shutdown (LMWPE) having a weight-average molecular weight of 4500 or less and an inert filler. Both membranes have a thickness of 5–75 microns, a porosity of 30–95%, an air permeability of 1–200 sec/10 cc, an average pore diameter of 0.001 to 1 micron and puncture strength of more than 300 grams/25 {circumflex over (l)}¼ m.

Abstract: A separator membrane for use in silver-zinc batteries is produced by extruding a blend of two fillers with the same chemical formula but different particle size. A polyolefine polymer and a plasticizer are blended and extruded to form a thin sheet of 1 to 10 mil thickness. The plasticizer is then extracted to leave submicron voids in the membrane. Plasticizers are added as processing aids, and can be either soluble or insoluble in water, and include petroleum oils, lubricating oils, fuel oils, and natural oils such as tall oils and linseed oils. The oil are then extracted from the membrane by conventional procedures such as single stage extraction using a suitable solvent. Commercially available wetting agents known to the art such as dodecylphenoxy polyethoxy ethanol and isooctyl phenyl polyethoxy ethanol are coated onto the sheet to improve wettability. The sheet is then dried, and boiled in distilled water for one minute or more, before being finally dried.