A composition containing a) a natural or synthetic polymer and b) one or more compounds of the formula (I), (II) or (III) wherein R
1
, R
2
and R
3
or Y
1
, Y
2
and Y
3
or Z
1
, Z
2
and Z
3
are e.g. branched C
3
-C
20
alkyl.
Process for transforming polypropylene into a crystal modification of high transparency and articles resulting from said process
申请人:Borealis AG
公开号:EP2371517A1
公开(公告)日:2011-10-05
The invention relates to a process for producing polypropylene articles comprising a high relative content of the orthorhombic gamma-crystal modification by applying four consecutive process steps, namely (a) heating a polypropylene composition comprising a propylene random copolymer and an alpha-crystal nucleating agent to form a melt, (b) shearing said melt at a high apparent shear rate, (c) shaping said melt into an article, and (d) cooling said melt in a specific range of cooling rate to obtain polypropylene articles of high transparency