| 摘要 |
Film consists of polypropylene contg. 0.01-2 wt% of (a) an organic acid (or deriv.), (b) a sorbitol deriv., (c) a pigment, or (d) a finely divided inorganic powder, with 20-60 wt% sol. in boiling n-heptane, and with a monoclinic crystal structure in the crystalline portion. Propylene (co)polymers with not more than 10 wt% of another olefine are used. The polymer has a melt-flow rate of 0.01-50 g/10 mins. (190 deg.C, 2160 g). Of the portion sol. in boiling n-haptane, at least 30 wt% is insol. in boiling diether ether. The polypropylene is esp. pref. by a simplified, solvent-free polymerisation in bulk or gas phase, using a highly active catalyst comprising a Ti cpd. on a Mg cpd. as carrier, and an organo- Al cpd.
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