Polyethylene compositions and articles made therefrom
This invention relates to a polyethylene composition, and films therefrom, comprising at least 65 wt % ethylene derived units and from 0.1 to 35 wt % of C 3 -C 12 olefin comonomer derived units, where the polyethylene composition has: a) an RCI,m of less than 85 kg/mol; b) a Tw 1 −Tw 2 value of from −15 to −40° C.; and c) an Mw 1 /Mw 2 value of less than 1.5 where the film has a) a heat seal initiation temperature of X ° C. or less at 5 N of force, where X=0.0015×Y(psi)+62.6 (where Y is the average 1% Secant modulus ((MD+TD)/2)) of the film; b) a dart drop impact of 300 g/mil or more; c) an MD Elmendorf tear of 230 g or more; and d) average 1% Secant modulus ((MD+TD)/2) of 20,000 psi or more.
1. A polyethylene composition comprising at least 65 wt % ethylene derived units and from 0.1 to 35 wt % of C 3 -C 12 olefin comonomer derived units, based upon the total weight of the polyethylene composition; wherein the polyethylene composition has:
a) an RCI,m of less than 85 kg/mol;
b) a T w1 −T w2 value of from −15 to −40° C.; and
c) an M w1 /M w2 value of less than 1.5;
and one or more of the following:
d) a density of from 0.890 to 0.940 g/cm3;
e) a melt index (MI) of from 0.1 to 30 g/10 min;
f) a melt index ratio (I 21 /I 2 ) of from 12 to 90;
g) an M w /M n of from 2 to 10;
h) an M z /M w of from 1.5 to 5.0;
i) an M z /M n of from 3 to 50; and
j) a g′(vis) of 0.90 or greater.
2. The polyethylene composition of claim 1 , wherein the C 3 -C 12 olefin comonomer derived units are C 4 -C 8 α-olefin comonomer derived units.
3. The polyethylene composition of claim 1 , wherein the polyethylene composition comprises from 0.5 to 20 wt % of propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, and dodecene comonomer derived units, based upon the total weight of the polyethylene composition.
4. The polyethylene composition of claim 1 , wherein the polyethylene composition comprises from 1 to 10 wt % of C 4 -C 8 α-olefin comonomer derived units, based upon the total weight of the polyethylene composition.
5. The polyethylene composition of claim 1 , wherein the polyethylene composition has a T w1 −T w2 value of from −20 to −35° C.
6. The polyethylene composition of claim 1 , wherein the polyethylene composition has a T w1 −T w2 value of from −23 to −35° C.
7. The polyethylene composition of claim 1 , wherein the polyethylene composition has an M w1 /M w2 value of from 0.3 to 1.3.
8. The polyethylene composition of claim 6 , wherein the polyethylene composition has an M w1 /M w2 value of from 0.6 to 1.2.
9. The polyethylene composition of claim 1 , wherein the polyethylene composition has a melt index (MI) of from 0.1 g/10 min to 6 g/10 min.
10. The polyethylene composition of claim 1 , wherein the polyethylene composition has a melt index ratio (I 21 /I 2 ) of from 15 to 45.
11. The polyethylene composition of claim 1 , wherein the polyethylene composition has a high load melt index (I 21 ) of from 5 to 60 g/10 min.
12. The polyethylene composition of claim 1 , wherein the polyethylene composition has an Mw/Mn of from 2 to 8.
13. The polyethylene composition of claim 1 , wherein the polyethylene composition has:
a) an RCI,m of less than 40 kg/mol;
b) a T w1 −T w2 value of from −20 to −40° C.; and
c) an M w1 /M w2 value of less than 1.3;
d) a density of from 0.910 to 0.940 g/cm3;
e) a melt index (MI) of from 0.1 to 10 g/10 min;
f) a melt index ratio (I 21 /I 2 ) of from 15 to 35;
g) an M w /M n of from 2 to 8;
h) an M z /M w of from 1.8 to 5.0;
i) an M z /M n of from 4.0 to 16; and
j) a g′(vis) of 0.95 or greater.
14. The polyethylene composition of claim 1 , wherein the polyethylene composition has a density of from 0.900 g/cm 3 to 0.930 g/cm 3 .
15. The polyethylene composition of claim 1 , wherein the polyethylene composition has an RCI,m of 40 or less.
16. The polyethylene composition of claim 1 , wherein the polyethylene composition has a total unsaturation per 1000 C, as measured by 1 H NMR, of 0.6 or less.
17. An article made from the polyethylene composition of claim 1 , wherein the article is a blown film or cast film.
18. A film made from the polyethylene composition of claim 1 , wherein the film has a heat seal initiation temperature of X° C. or less at 5 N of force, where X=0.0015×Y(psi)+62.6 (where Y is the average 1% Secant modulus ((MD+TD)/2)) of the film.
19. The article of claim 18 , wherein the film exhibits an average MD/TD modulus of between 20,000 psi and 40,000 psi.
20. The article of claim 18 , wherein the film has a dart drop impact resistance of 300 g/mil or greater.
21. The article of claim 18 , wherein the film has a dart drop impact resistance of 350 g/mil or greater.
22. The article of claim 18 , wherein the film has an Elmendorf tear resistance of 250 g/mil or greater in the machine direction (MD).
23. The article of claim 18 , wherein the film has an Elmendorf tear resistance of 300 g/mil or greater in the machine direction (MD).
24. The article of claim 17 , wherein the film has:
a) a heat seal initiation temperature of X° C. or less at 5 N of force, where X=0.0015×Y(psi)+62.6 (where Y is the average 1% Secant modulus ((MD+TD)/2)) of the film;
b) a dart drop impact of 300 g/mil or more;
c) an MD Elmendorf tear of 230 g or more; and
d) average 1% Secant modulus ((MD+TD)/2) of 20,000 psi or more.
25. The article of claim 17 , wherein the polymer composition has an MIR of 15 to 55, and the film has an Elmendorf tear resistance of 230 g/mil or more in the machine direction (MD), and/or a dart drop impact resistance of at least 300 g/mil or more.
26. The polyethylene composition of claim 1 , wherein the polyethylene composition has a T 75 -T 25 value greater than or equal to 20.0.