Oriented Films Comprising Ethylene-Based Polymers and Methods of Making the Same
AssigneeExxonMobil Chemical Patents Inc.
InventorsEtienne R.H. Lernoux, Giriprasath Gururajan, Donald A. Winesett, Stefan B. Ohlsson
Life of this patent
Estimating the term…
Abstract
Provided are oriented films comprising linear low density polyethylene polymer and having improved balance of properties including improved machine direction tear strength. The oriented polymer film has at least one layer comprising 50 to 100 wt. % of an ethylene-based polymer. The MDO polymer film has a normalized MD Elmendorf Tear (ASTM D-1922) of at least 40 g/μm. In certain embodiments, the MDO polymer film surprisingly does not tear when MD Elmendorf Tear is measured according to ASTM D-1922.
Claims25
A machined direction oriented (MDO) polymer film comprising:
- at least one layer comprising 50 to 100 wt. % of an ethylene-based polymer having:
- i. a melt index (I2.16) of from about 0.1 g/10 min to about 10.0 g/10 min;
- ii. a melt index ratio (I21.6/I2.16) of from about 15 to about 100;
- iii. a weight average molecular weight (Mw) of from about 20,000 to about 200,000;
- iv. a molecular weight distribution (Mw/Mn) of from about 2.0 to about 5.0;
- v. a Mz/Mw ratio of from 1.7 to about 3.5;
- and
- vi. a density of from 0.900 to 0.925 g/cm3,
- wherein the MDO polymer film has a normalized MD Elmendorf Tear of at least 40 g/μm.
A method to produce a machined direction oriented (MDO) polymer film comprising stretching a polymer film in the machine direction after the polymer film has cooled to a crystalline structure to produce a MDO polymer film wherein the MDO polymer film has a normalized MD Elmendorf Tear of at least 40 g/μm and wherein the polymer film comprises at least one layer comprising 50 to 100 wt. % of an ethylene-based polymer having:
- i. a melt index (I2.16) of from about 0.1 g/10 min to about 10.0 g/10 min;
- ii. a melt index ratio (I21.6/I2.16) of from about 15 to about 100;
- iii. a weight average molecular weight (Mw) of from about 20,000 to about 200,000;
- iv. a molecular weight distribution (Mw/Mn) of from about 2.0 to about 5.0;
- v. a Mz/Mw ratio of from 1.7 to about 3.5;
- and
- vi. a density of from 0.900 to 0.925 g/cm3.
Dependencies are inferred from the claim text.