| 摘要 |
PURPOSE:To obtain a microporous film, having high porosity and suitable for moisture-permeable and waterproofing uses, etc., by blending a polyolefin with specific amounts of an inorganic material and beta-nucleating agent, melt extruding the resultant blend at a specific temperature and drawing the resultant extrudate. CONSTITUTION:(A) 100pts.wt. polyolefin, e.g. polypropylene, etc., is blended and mixed with (B) 10-400pts.wt., preferably 20-200pts.wt. inorganic material, e.g. diatomaceous earth, etc., and (C) 0.001-10pts.wt., preferably 0.002-5pts.wt. beta-nucleating agent, e.g. quinacridone, etc., and the resultant blend is then melt extruded at a temperature of >=the melting point (Tm) of the polyolefin+20 deg.C - <=Tm+100 deg.C, kept at a temperature below the melt crystallization temperature (Tmc) - >=Tmc-50 deg.C and biaxially drawn to afford the aimed microporous film having 30-80% porosity. |
