CPC C08J 5/18 (2013.01) [C08L 23/0815 (2013.01); C08J 2323/06 (2013.01); C08J 2323/08 (2013.01); C08J 2423/06 (2013.01); C08J 2423/08 (2013.01); C08L 2203/16 (2013.01); C08L 2205/025 (2013.01); C08L 2207/07 (2013.01)] | 16 Claims |
1. A polymer composition comprising:
(A) 10 wt. % to 50 wt. % of a Ziegler-Natta-catalyzed LLDPE polymer that is heterogeneously branched, has polymer units derived from ethylene and at least one of butene-1 and hexene-1, and has (i) density from 0.917 to 0.926 g/cm3, (ii) melt index from 0.7 g/10 min to 2.0 g/10 min, and (iii) a CDBI of less than 50.0%; and
(B) 90 wt. % to 50 wt. % of a metallocene-catalyzed LLDPE polymer having:
i. a melt index of from about 0.5 g/10 min to about 1.0 g/10 min,
ii. a melt index ratio of from about 20 to about 40,
iii. a weight average molecular weight (Mw) of from about 20,000 to about 200,000 g/mol,
iv. a molecular weight distribution (Mw/Mn) of from about 2.0 to about 4.5;
v. a density of from 0.915 to 0.921 g/cm3,
vi. a first peak and a second peak in a comonomer distribution analysis, wherein the first peak has a maximum at a log(Mw) value of 4.3 to 4.7 and a TREF elution temperature of 85.0° C. to 91.0° C. and the second peak has a maximum at a log(Mw) value of 5.1 to 5.4 and a TREF elution temperature of 60.0° C. to 65.0° C., and
vii. a CDBI of less than 35.0%,
wherein:
a film of the polymer composition has an MD Elmendorf Tear value greater than an expected MD Elmendorf Tear value determined from a blend rule for a film made from a blend comprising the Ziegler-Natta-catalyzed LLDPE and the metallocene-catalyzed LLDPE,
where the blend rule is defined as:
wherein MDTearx is the MD Elmendorf Tear value for a film having x wt % of the Ziegler-Natta-catalyzed LLDPE; wt. %xZN1 is the weight percent of the Ziegler-Natta-catalyzed LLDPE in the blend; and further provided that wt % of the Ziegler-Natta-catalyzed LLDPE and wt % of the metallocene-catalyzed LLDPE add to 100 wt %.
|