Ethylene/1-butene copolymers with enhanced resin processability
AssigneeNOVA Chemicals (International) S.A.
InventorsPatrick Lam, Victoria Ker, Robert Quaiattini
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Abstract
Ethylene/1-butene copolymers made with a single site catalyst system have high melt strength and good processability.
Claims8
A process for making an ethylene/1-butene copolymer, the process comprising polymerizing ethylene and 1-butene with a single site catalyst system in a gas phase polymerization reactor, wherein the ethylene/1-butene copolymer has density of from 0.912 to 0.94 g/cm3, a melt index (12) of from 0.5 to 10 g/10 min, a melt flow ratio (121/12) of from 20 to 35, a molecular weight distribution (Mw/Mn) of from 2.0 to 4.5, and an accelerated haul-off melt strength (σMS) as determined by Rosand capillary rheometry at 190° C., of at least 3.0 cN;
- wherein the single site catalyst system comprises a phosphinimine catalyst, a cocatalyst and an inert support.
A process for making an ethylene/1-butene copolymer, the process comprising polymerizing ethylene and 1-butene with a single site catalyst system in a gas phase polymerization reactor, wherein the ethylene/1-butene copolymer has density of from 0.912 to 0.94 g/cm3, a melt index (I2) of from 0.5 to 10 g/10 min, a melt flow ratio (I21/I2) of from 20 to 35, a molecular weight distribution (Mw/Mn) of from 2.0 to 4.5, and which satisfies the following relationship:
- (CDBI50/δXO)3.0≤6.5−5.7 log [a(1.5(I21/I2)+(Mw/Mn))];
- where CDBI50 is the composition distribution breadth index, δXO is the crossover phase angle at a frequency of 1.0 rad/s and a is the CY a parameter.
Dependencies are inferred from the claim text.