Long-Chain Branched Ethylene Copolymer With Novel Composition Distribution and Films Formed from the Same
AssigneeFormosa Plastics Corporation, U.S.A.
InventorsPeng Li, Ming-Yung Lee, Tieqi Li, Honglan Lu
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Abstract
What is disclosed is a Ziegler-Natta catalyzed ethylene and alpha-olefin LLDPE copolymer having a unique composition distribution and long chain-branching. The polymers of the present invention inherently exhibit outstanding melt strength with great bubble stability, sufficient flexibility, excellent gel performance, as well as desirable mechanical properties such as balanced toughness and stiffness, which are desirable properties for thick gauge film applications. Specifically, the polymers of the present invention.
Claims21
A Ziegler-Natta catalyzed ethylene and alpha-olefin LLDPE copolymer, comprising:
- a) density in the range from about 0.910 g/cc to about 0.930 g/cc;
- b) melt index (I2) in the range from about 0.2 dg/min to about 0.8 dg/min;
- c) melt index ratio (I21/I2) in the range from about 25 dg/min to about 45 dg/min;
- d) polydispersity index (Mw/Mn) in the range from about 3.0 to about 5.0;
- e) polydispersity index (Mz/Mw) greater than 2.5;
- f) peak melting point in the range from about 123° C. to about 127° C.;
- g) at least 15% of Temperature Raising Elusion Fraction (TREF) fraction below an elution temperature of 35° C.;
- h) weight average molecular weight (Mw) is substantially constant over the entire FREF fraction distribution, wherein the Mw at 100° C. divided by the Mw at 35° C. is in the range from about 1.0 to about 1.5;
- i) zero-shear-viscosity (η°) at 190° C. is in the range of about 2×104 to about 1×107 Pa·s;
- j) long-chain-branching (LCB) is in the range from about 5 to about 50 per million total carbon atoms.
The copolymer of claim 20, wherein the titanium-based Ziegler-Natta catalyst comprises:
- a. magnesium;
- b. a compound having the formula R1mSi(OR2)n, wherein R1 and R2 are C1-C20 carbon atoms, m=0-3, n=1-4, and m+n=4, and wherein each R1 and each R2 may be the same or different;
- c. a compound having the formula R3xSiXy, wherein R3 is C1-C20 carbon atoms, X is halogen, x=0-3, y=1-4, and x+y=4, and wherein each X and each R3 may be the same or different;
- d. a compound having the formula MX4 and M(OR4)X4, wherein M is a titanium, wherein R4 is C1-C20 carbon atoms, X is halogen, and wherein each R4 may be the same or different;
- e. a substituted aromatic nitrogen compound;
- and
- f. an alkyl halide or aromatic halide compound having the formula R5X, wherein R5 is an alkyl group containing 3 to 20 carbon atoms or an aromatic group containing 6 to 18 carbon atoms, and X is selected from chlorine and bromine.
Dependencies are inferred from the claim text.