Catalyst system for the production of polyolefins and method of making and using same
Catalyst systems for polymerization of mixtures comprising an olefin include a selectivity control agent comprising at least one silicon-containing compound containing at least one C1-C10 alkoxy group bonded to a silicon atom and an amount of one or more agent compounds. The agent compound comprises C2-C13 mono- or polycarboxylic esters of aliphatic C2-C7 carboxylic acids and inertly substituted derivatives thereof. One or more polymerization catalysts may also be present. A polymerization process includes contacting an olefin or a mixture of the olefin and one or more copolymerizable comonomers under polymerization conditions with the catalyst composition.
1. A composition comprising a propylene homopolymer and a C2-C13 mono- or polycarboxylic ester of aliphatic C2-C7 carboxylic acids and inertly substituted derivatives thereof, wherein the composition has a melt flow greater than 100 g/10 min, as measured in accordance with ASTM D-1238-01 at 230° C. with a 2.16 kg weight of propylene based polymers.
2. The composition of claim 1 , wherein the composition has a VOC content less than 80 ppm, as measured in accordance with VW standard PV 3341.
3. The composition of claim 1 , wherein the composition has a VOC content less than 25 ppm, as measured in accordance with VW standard PV 3341, and a melt flow less than 10 g/10 min, as measured in accordance with ASTM D-1238-01 at 230° C. with a 2.16 kg weight of propylene based polymers.
4. A propylene impact copolymer composition comprising:
a propylene-based polymer;
a propylene/ethylene copolymer dispersed within the propylene-based polymer; and
a C2-C13 mono- or polycarboxylic ester of aliphatic C2-C7 carboxylic acids and inertly substituted derivatives thereof, wherein the composition has a melt flow greater than 50 g/10 min, as measured in accordance with ASTM D-1238-01 at 230° C. with a 2.16 kg weight of propylene based polymers.
5. The composition of claim 4 , wherein the composition has a VOC content less than 30 ppm, as measured in accordance with VW standard PV 3341.
6. A polymerization process comprising:
contacting, under polymerization conditions, propylene with a catalyst composition comprising a C2-C13 mono- or polycarboxylic ester of aliphatic C2-C7 carboxylic acids and inertly substituted derivatives thereof in a first polymerization reactor;
forming an active propylene-based polymer;
contacting, under polymerization conditions, the active propylene-based polymer with at least one olefin in a second polymerization reactor; and
forming the composition of claim 4 .
7. An article comprising the composition of claim 1 .
8. An article comprising the polypropylene impact copolymer of claim 4 .