| 摘要 |
The present invention relates to improved processability of polyolefin films through the addition to the basic isotactic polypropylene (iPP) polymer of a syndiotactic polypropylene (sPP) in an amount within the range of about 2 to 10 weight percent and of a resin or rosin modifier in an amount within the range of 1 to 30 weight percent. Preferably, the composition could contain syndiotactic propylene in an amount within the range of about 2 to 5 weight percent. Preferably, about 3 weight percent of syndiotactic propylene is present in the polyolefin composition. The resin or rosin modifier could, preferably, be present in an amount within the range of 5 to 10 weight percent. Preferably, the composition should contain about 10 weight percent of the modifier. The present invention encompasses both the resulting polyolefin films and the process for producing such films. The improved processability of the film includes fewer webs breaks and drawability at higher line speeds, resulting in fewer shut downs of the processing line and a decrease in manufacturing time. These improvements are measured in terms of variable machine direction orientation draw ratios and transverse direction orientation oven temperatures.
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