| 摘要 |
PURPOSE:To obtain the subject product excellent in transparency, blocking resistance, haze value and appearance without requiring troublesome pretreatment by using a polypropylene resin composition consisting of a blend of a specific polypropylene with a silica having specific properties. CONSTITUTION:A polypropylene resin composition obtained by blending (A) 100 pts.wt. polypropylene resin having 1-5g/10min melt flow rate with (B) 0.01-0.4 pts.wt. synthetic silica having <=2mum average particle diameter and <=0.5ml/g pore volume is used as a raw material to provide the objective product. This composition is preferably obtained by subjecting the component A to dry blending with the component B, then melting and kneading the blend at 190-300 deg.C and pelletizing the kneaded material. Although the objective product is usually obtained by biaxially stretching an unstretched film or sheet consisting of this composition, a tender method as a successive biaxial stretching method is preferably used as the biaxial stretching method. Stretching temperature is preferably 155-175 deg.C and stretching rate is preferably 10-150%. |
