Dual catalyst system for producing high density polyethylenes with long chain branching
Disclosed herein are ethylene-based polymers generally characterized by a melt index of less than 1 g/10 min, a density from 0.93 to 0.965 g/cm 3 , a CY-a parameter at 190° C. of less than 0.2, an average number of short chain branches per 1000 total carbon atoms of the polymer in a molecular weight range of 400,000 to 600,000 g/mol that is greater than that in a molecular weight range of 40,000 to 60,000 g/mol, and an average number of long chain branches per 1000 total carbon atoms of the polymer in a molecular weight range of 400,000 to 600,000 g/mol that is greater than that in a molecular weight range of 4,000,000 to 6,000,000 g/mol. The ethylene polymers can be used to fabricate pipes, blown films, and blow molded products, and the ethylene polymers can be produced with a dual catalyst system containing a single atom bridged or two carbon atom bridged metallocene compound with two indenyl groups or an indenyl group and a cyclopentadienyl group, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group with an alkenyl substituent.
1. An ethylene polymer having:
a melt index of less than or equal to about 1 g/10 min;
a density in a range from about 0.93 to about 0.965 g/cm 3 ;
a CY-a parameter at 190° C. of less than or equal to about 0.2;
an average number of short chain branches (SCB's) per 1000 total carbon atoms of the polymer in a molecular weight range of 400,000 to 600,000 g/mol that is greater than that in a molecular weight range of 40,000 to 60,000 g/mol; and
an average number of long chain branches (LCB's) per 1000 total carbon atoms of the polymer in a molecular weight range of 400,000 to 600,000 g/mol that is greater than that in a molecular weight range of 4,000,000 to 6,000,000 g/mol.
2. An article of manufacture comprising the polymer of claim 1 .
3. The polymer of claim 1 , wherein:
the average number of SCB's per 1000 total carbon atoms of the polymer in the molecular weight range of 400,000 to 600,000 g/mol is at least 50% greater than that in the molecular weight range of 40,000 to 60,000 g/mol; and
the average number of LCB's per 1000 total carbon atoms of the polymer in the molecular weight range of 400,000 to 600,000 g/mol is at least 100% greater than that in the molecular weight range of 4,000,000 to 6,000,000 g/mol.
4. The polymer of claim 1 , wherein:
the melt index is less than or equal to about 0.5 g/10 min;
the density is in a range from about 0.93 to about 0.958 g/cm 3 ; and
the CY-a parameter at 190° C. is in a range from about 0.03 to about 0.15.
5. The polymer of claim 4 , wherein the ethylene polymer comprises an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, an ethylene/1-octene copolymer, or a combination thereof.
6. The polymer of claim 5 , wherein the ethylene polymer has a HLMI in a range from about 10 to about 45 g/10 min.
7. The polymer of claim 1 , wherein the ethylene polymer has:
a ratio of M w /M n in a range from about 3.5 to about 18; and
a ratio of M z /M w in a range from about 3.5 to about 10.
8. The polymer of claim 1 , wherein the ethylene polymer has:
a M n in a range from about 10,000 to about 100,000 g/mol;
a M w in a range from about 100,000 to about 400,000 g/mol; and
a M z in a range from about 500,000 to about 2,500,000 g/mol.
9. The polymer of claim 1 , wherein the ethylene polymer contains from about 0.02 to about 0.05 LCB's per 1000 total carbon atoms.
10. The polymer of claim 1 , wherein the ethylene polymer has an average number of LCB's in a range from about 0.03 to about 0.07 LCB's per 1000 total carbon atoms in the molecular weight range of 400,000 to 600,000 g/mol.
11. The polymer of claim 1 , wherein the ethylene polymer has a zero-shear viscosity in a range from about 1×10 6 to about 1×10 16 Pa-sec at 190° C.
12. The polymer of claim 1 , wherein the ethylene polymer comprises an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, an ethylene/1-octene copolymer, or a combination thereof.
13. The polymer of claim 12 , wherein the ethylene polymer has:
a ratio of M w /M n in a range from about 6 to about 16; and
a ratio of M z /M w in a range from about 5 to about 8.
14. The polymer of claim 12 , wherein the ethylene polymer has:
a M n in a range from about 10,000 to about 40,000 g/mol;
a M w in a range from about 100,000 to about 300,000 g/mol;
a M z in a range from about 750,000 to about 1,500,000 g/mol; and
an average number of LCB's in a range from about 0.03 to about 0.06 LCB's per 1000 total carbon atoms in the molecular weight range of 400,000 to 600,000 g/mol.
15. An article of manufacture comprising the polymer of claim 14 .
16. The polymer of claim 12 , wherein:
the average number of SCB's per 1000 total carbon atoms of the polymer in the molecular weight range of 400,000 to 600,000 g/mol is at least 75% greater than that in the molecular weight range of 40,000 to 60,000 g/mol; and
the average number of LCB's per 1000 total carbon atoms of the polymer in the molecular weight range of 400,000 to 600,000 g/mol is at least 200% greater than that in the molecular weight range of 4,000,000 to 6,000,000 g/mol.
17. An olefin polymerization process, the process comprising contacting a catalyst composition with an olefin monomer and an olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer, wherein:
the catalyst composition comprises:
catalyst component I comprising a single atom bridged or two carbon atom bridged metallocene compound with two indenyl groups or an indenyl group and a cyclopentadienyl group;
catalyst component II comprising a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group with an alkenyl substituent;
an activator; and
optionally, a co-catalyst; and
the olefin polymer is characterized by:
a melt index of less than or equal to about 1 g/10 min;
a density in a range from about 0.93 to about 0.965 g/cm 3 ;
a CY-a parameter at 190° C. of less than or equal to about 0.2;
an average number of short chain branches (SCB's) per 1000 total carbon atoms of the polymer in a molecular weight range of 400,000 to 600,000 g/mol that is greater than that in a molecular weight range of 40,000 to 60,000 g/mol; and
an average number of long chain branches (LCB's) per 1000 total carbon atoms of the polymer in a molecular weight range of 400,000 to 600,000 g/mol that is greater than that in a molecular weight range of 4,000,000 to 6,000,000 g/mol.
18. An ethylene polymer having:
a melt index of less than or equal to about 1 g/10 min;
a density in a range from about 0.93 to about 0.965 g/cm 3 ;
a M w in a range from about 100,000 to about 400,000 g/mol;
a CY-a parameter at 190° C. of less than or equal to about 0.2;
from about 0.01 to about 0.06 LCB's per 1000 total carbon atoms;
an average number of short chain branches (SCB's) per 1000 total carbon atoms of the polymer in a molecular weight range of 400,000 to 600,000 g/mol that is greater than that in a molecular weight range of 40,000 to 60,000 g/mol; and
an average number of long chain branches (LCB's) per 1000 total carbon atoms of the polymer in a molecular weight range of 400,000 to 600,000 g/mol that is greater than that in a molecular weight range of 4,000,000 to 6,000,000 g/mol.
19. The polymer of claim 18 , wherein the ethylene polymer comprises an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, an ethylene/1-octene copolymer, or a combination thereof.
20. The polymer of claim 19 , wherein the ethylene polymer has a HLMI in a range from about 3 to about 40 g/10 min.
21. An article of manufacture comprising the polymer of claim 19 .
22. The polymer of claim 19 , wherein the ethylene polymer has an average number of LCB's in a range from about 0.015 to about 0.085 LCB's per 1000 total carbon atoms in the molecular weight range of 400,000 to 600,000 g/mol.
23. The polymer of claim 19 , wherein:
the melt index is less than or equal to about 0.5 g/10 min;
the density is in a range from about 0.93 to about 0.958 g/cm 3 ; and
the CY-a parameter at 190° C. is in a range from about 0.03 to about 0.15.
24. The polymer of claim 23 , wherein the ethylene polymer has:
a ratio of M w /M n in a range from about 3.5 to about 18; and
a ratio of M z /M w in a range from about 3.5 to about 10.
25. The polymer of claim 18 , wherein:
the average number of SCB's per 1000 total carbon atoms of the polymer in the molecular weight range of 400,000 to 600,000 g/mol is at least 50% greater than that in the molecular weight range of 40,000 to 60,000 g/mol; and
the average number of LCB's per 1000 total carbon atoms of the polymer in the molecular weight range of 400,000 to 600,000 g/mol is at least 100% greater than that in the molecular weight range of 4,000,000 to 6,000,000 g/mol.
26. The polymer of claim 25 , wherein the ethylene polymer comprises an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, an ethylene/1-octene copolymer, or a combination thereof.
27. The polymer of claim 26 , wherein the ethylene polymer has a HLMI in a range from about 10 to about 45 g/10 min.
28. The polymer of claim 27 , wherein the ethylene polymer has:
a ratio of M w /M n in a range from about 6 to about 16; and
a ratio of M z /M w in a range from about 5 to about 8.
29. The polymer of claim 26 , wherein the ethylene polymer has:
a M n in a range from about 10,000 to about 40,000 g/mol;
a M z in a range from about 750,000 to about 1,500,000 g/mol; and
an average number of LCB's in a range from about 0.02 to about 0.07 LCB's per 1000 total carbon atoms in the molecular weight range of 400,000 to 600,000 g/mol.
30. An article of manufacture comprising the polymer of claim 29 .