Syndiotactic propylene-based ethylene-propylene copolymers
AssigneeExxonMobil Chemical Patents Inc.
InventorsJingwen Zhang, Jo Ann M. Canich, Peijun Jiang, John R. Hagadorn, Chase A. Eckert, Sarah J. Mattler, Shuhui Kang
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Abstract
Provided is syndiotactic polypropylene-based ethylene-propylene copolymers comprising a) 5 to 15% by weight of ethylene and 85 to 95% by weight of propylene; b) 60 to 90% rr triads; c) Mw (LS) of 10 to 250 kg/mol; and d) no substantial melting peak, wherein the heat of fusion of the peak is 5 J/g or less as determined by differential scanning calorimetry at a scan rate of 10° C./min (ASTM D3418-03).
Claims8
A process to produce syndiotactic propylene copolymers comprising contacting in a homogeneous phase propylene and ethylene with a catalyst system comprising activator and catalyst compound;
- and obtaining a syndiotactic propylene copolymers comprising (a) from 85 to 95 weight % of propylene, based upon the weight of the polymer;
- (b) 60 to 90% rr triads;
- (c) Mw (LS) of 10 to 250 kg/mol;
- and (d) no substantial melting peak, wherein the heat of fusion of the peak is 5 J/g or less as determined by differential scanning calorimetry at a scan rate of 10° C./min (ASTM D3418-03), wherein the catalyst system comprises a catalyst compound represented by formula (1a);
- wherein:
- M is zirconium:
- G is di(para-triethylsilylphenyl)methylene or diphenylmethylene;
- each Rd, Ra and Rc is hydrogen;
- each Rb is methyl, ethyl, propyl, or butyl;
- and
- each X is, independently, methyl or chloro.
Dependencies are inferred from the claim text.