| 摘要 |
PURPOSE:To have high strength and improve permeation by using high molecular weight polyethylene of viscosity average molecular weight 400,000 or more, tensile strength of 5kg/mm<2> or more and nitrogen gas permeability coefficient of 1.0X10<-6> (ml.cm/sec.cm<2>.cmHg) or more. CONSTITUTION:20wt.% of polyethylene of viscosity average molecular weight 400,000 or more is power-blended with 80wt.% of stearyl alcohol, and the mixture is then stool in an oven, thereby wetting polyethylene in alcohol. In this case, 0.5 weight part of phenol stabilizer is added to 100 weight parts of the mixture. By heating and kneading, the uniform mixture is obtained. Before solidifying in cooling, the uniform mixture is formed by pressing. The resultant sheet is immersed in ethanol, so that stearyl alcohol is extracted. The sheet after extraction is elongated longitudinal and laterally 4X4 times. Consequently, the values are obtained. The film used as a separator for a battery exhibits high strength and good permeability. |
