Patent ID: 6262203
Filing Date: 2001-07-17
Classification: C08F,Y10S

Abstract:
A method of forming thermoplastic elastomeric propylene polymer, that comprises, in the presence of MAO, homopolymerizing a monomer of propylene with a metallocene propylene polymerization catalyst of metals selected from the group consisting of Ti, Zr and Hf, that can cause polymerization along two propagation paths, wherein one propagation path causes homopolymerization of the propylene stereoselectively into crystallizable blocks in the resulting chain, and the other polymerization path creates irregular non-crystallizable amorphous blocks, the catalyst enabling interconversions along the two paths during the polymerization and creation of the chain, whereby the propylene is polymerized with alternating stereo-regular crystallizable polymerized blocks and stereo-irregular non-crystallizable polymerized blocks, with the former held between the non-crystallizable blocks to enable elastic recovery when stretched and released.