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US 11,377,460 B2Granted
Methods for adjusting a polymer property
AssigneeUnivation Technologies, LLC
InventorsJohn F. Szul, E. J. Markel, R. Eric Pequeno, Bruce J. Savatsky
Life of this patent
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Abstract
Embodiments of the present disclosure are directed towards methods of adjusting melt index and/or density utilizing a metallocene complex represented by Formula (I): wherein each n-Pr is n-propyl, and each X is independently CH3, CI, Br, or F.
Claims6
A method for adjusting melt index, the method comprising:
- activating a metallocene complex represented by Formula I:
- wherein each n-Pr is n-propyl, and each X is independently CH3, Cl, Br, or F to provide an activated metallocene complex;
- contacting ethylene and a comonomer with the activated metallocene complex to produce a first polymer having a predetermined density from 0.890 g/cm3 to 0.970 g/cm3 and a first melt index from 0.01 dg/min to 1000 dg/min, wherein the ethylene is present at a concentration from 50 wt % to 95 wt % and the comonomer is present at a comonomer concentration from 5 wt % to 50 wt % and hydrogen s present at a gas mole ratio of hydrogen to the monomer from 0.0001 to 0.7;
- and
- reducing the hydrogen concentration to produce a second polymer having the predetermined density and a second melt index that is lesser than the first melt index, wherein comonomer concentration is reduced 10 to 35 percent on a mass basis during polymerization.
2 more elements
A method for adjusting density, the method comprising:
- activating a metallocene complex represented by Formula I:
- wherein each n-Pr is n-propyl, and each X is independently CH3, Cl, Br, or F to provide an activated metallocene complex;
- contacting ethylene and a comonomer with the activated metallocene complex in the presence of hydrogen to produce a first polymer having a first density from 0.890 g/cm3 to 0.970 g/cm3 and a first melt index from 0.01 dg/min to 1000 dg/min, wherein the hydrogen is present at a first gas mole ratio of hydrogen to the monomer from 0.0001 to 0.7, ethylene is present at a concentration from 50 wt % to 95 wt %, and the comonomer is present at a comonomer concentration from 5 wt % to 50 wt %;
- and
- reducing the first hydrogen concentration to a second hydrogen concentration while maintaining the ethylene consumption to produce a second polymer having a second density that is lesser than the first density and a second melt index that is lesser than the first melt index.
2 more elements
Dependencies are inferred from the claim text.