| 摘要 |
<p>PURPOSE:To polypropylene composition with is free from hazards such as bridging in hopper and dust explosion, by adding a lubricant to polypropylene particles containing a blowing agent, and having a specific apparent density. CONSTITUTION:To 100pts.wt. of polypropylene particles having an apparent density of at least 0.5g/cc, pref., at least 0.52g/cc, are added 0.01-0.6pts.wt. of a lubricant and 0.01-50pts.wt. of a blowing agent. As the polypropylene particles, those having a particle size distribution represented by the expression are used preferably, wherein Dp is a particle diameter (mu); R(Dp) is a cumulative weight percentage of particles retained on sieve, i.e., a weight percentage of particles having diameters greater than Dp; De is a characteristic number of particle size and is a particle diameter when R(Dp)=36.8wt%; 100<=Dp1,200; R(Dp)=0-100; 100<= De<=800 and n>=2.5. As the lubricant, a metal salt of a saturated fatty acid or a fatty acid amide is preferred.</p> |
