Cast films comprising bimodal ethylene-based polymers having high molecular weight high density fractions

Patent metadata

Field	Value
Publication number	US-11926684-B2
Application number	US-201916973610-A
Country	US
Kind code	B2
Filing date	Jun 13, 2019
Priority date	Jun 15, 2018
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

A cast film inducing a bimodal ethylene-based polymer having a high density fraction (HDF) from 3.0% to 10.0%, an I 10 /I 2 ratio from 5.5 to 7.0, a short chain branching distribution (SCBD) less than or equal to 10° C., a density from 0.910 g/cc to 0.920 g/cc, and a melt index (I 2 ) from 1.0 g/10 mins to 8.0 g/10 mins.

First claim

The invention claimed is:

1. A cast film comprising a bimodal ethylene-based polymer comprising:
a high density fraction (HDF) from 3.0% to 10.0%, wherein the high density fraction is measured by crystallization elution fractionation (CEF) integration at temperatures from 93° C. to 119° C.;
an I 10 /I 2 ratio from 5.5 to 7.0, wherein I 2 is a melt index when measured according to ASTM D 1238 at a load of 2.16 kg and temperature of 190° C. and I 10 is a melt index when measured according to ASTM D 1238 at a load of 10 kg and temperature of 190° C.;
a short chain branching distribution (SCBD) less than or equal to 10° C., wherein the short chain branching distribution is measured by CEF full width at half height;
a density from 0.910 g/cc to 0.920 g/cc, wherein the density is measured in accordance with ASTM D792, Method B; and
a melt index (I 2 ) from 1.0 g/10 mins to 8.0 g/10 mins, wherein the melt index (I 2 ) is measured in accordance to ASTM D1238 at 190° C. at 2.16 kg.

2. The cast film of claim 1 , wherein the bimodal ethylene-based polymer has a density from 0.912 g/cc to 0.918 g/cc.

3. The cast film of claim 1 , wherein the bimodal ethylene-based polymer has a melt index (I 2 ) from 2.0 g/10 mins to 5.0 g/10 mins.

4. The cast film of claim 1 , wherein the bimodal ethylene-based polymer has a zero shear viscosity ratio from 1.1 to 3.0.

5. The cast film of claim 1 , wherein the cast film has average ultimate stretch from 250% to 400%.

6. The cast film of claim 1 , wherein the cast film has average stretch force at 200% stretch from 30.00 to 40.00 lbs measured at 0.5 mil thickness and 20 inch film width.

7. The cast film of claim 1 , wherein the cast film has average on pallet puncture using Type A Load Testing from 12.0 lbs. to 17.0 lbs measured at 0.5 mil thickness and 20 inch film width.

8. The cast film of claim 1 , wherein the cast film has average on pallet puncture using Type B Load Testing from 8.0 lbs. to 13.0 lbs. measured at 0.5 mil thickness and 20 inch film width.

9. The cast film of claim 1 , wherein the cast film has average pallet corner puncture using Type A Load Testing from 12.0 lbs. to 17.0 lbs. measured at 0.5 mil thickness and 20 inch film width.

10. The cast film of claim 1 , wherein the cast film has average on pallet peak load using Type A Load Testing from 38.0 lbs. to 41.0 lbs. measured at 0.5 mil thickness and 20 inch film width.

11. The cast film of claim 1 , wherein the cast film has average on pallet final load using Type A Load Testing from 29.0 lbs. to 33.0 lbs. measured at 0.5 mil thickness and 20 inch film width.

12. The cast film of claim 1 , wherein the cast film has average on pallet peak load using Type B Load Testing from 20.0 lbs. to 30.0 lbs. measured at 0.5 mil thickness and 20 inch film width.

13. The cast film of claim 1 , wherein the cast film has average on pallet final load using Type B Load Testing from 19.0 lbs. to 25.0 lbs. measured at 0.5 mil thickness and 20 inch film width.

14. The cast film of claim 1 , wherein the cast film comprises a mixture of the bimodal ethylene based polymer and at least one polymer selected from the group consisting of low density polyethylene, ultra-low density polyethylene, linear low density polyethylene, high density polyethylene, a propylene-based polymer, and mixtures thereof.

15. A layered cast film structure comprising a first layer and a second layer, wherein the first film layer comprises the bimodal ethylene-based polymer according to claim 1 , and
the second layer is comprised of propylene-based polymer.

16. The layered cast film structure of claim 15 , wherein the layered cast film structure comprises from 5.0 wt. % to 25.0 wt. % polypropylene.

17. The cast film of claim 16 , wherein the cast film has average on pallet tear using Type A Load Testing from 9.0 lbs. to 18.0 lbs. measured at 0.5 mil thickness and 20 inch film width.

Assignees

• Dow Global Technologies Llc

Inventors

• Hart Kyle E
• Demirors Mehmet
• Gambrel Timothy W
• Fontaine Philip P
• Kalihari Vivek
• Munj Hrishikesh R
• Hobson Jon W
• Patel Rajen M

Classifications

• C08F210/16 Primary

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• C08F2500/05

  Bimodal or multimodal molecular weight distribution · CPC title

• C08F2500/07

  High density, i.e. > 0.95 g/cm3 · CPC title

• C08F2500/10

  Short chain branches · CPC title