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

Patent metadata

Field	Value
Publication number	US-11873377-B2
Application number	US-201916973649-A
Country	US
Kind code	B2
Filing date	Jun 13, 2019
Priority date	Jun 15, 2018
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

A blown film having a bimodal ethylene-based polymer including a high density fraction (HDF) from 3.0% to 25.0%, an I10/I2 ratio from 5.5 to 7.5, a short chain branching distribution (SCBD) less than or equal to 10 C, a zero shear viscosity ratio from 1.0 to 2.5, a density from 0.902 g/cc to 0.925 g/cc, and a melt index (I2) from 0.5 g/10 mins to 2.0 g/10 mins.

First claim

The invention claimed is:

1. A blown film comprising a bimodal ethylene-based polymer comprising:
a high density fraction (HDF) from 3.0% to 25.0%, 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 7.5, 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 0.902 g/cc to 0.925 g/cc, wherein the density is measured in accordance with ASTM D792, Method B, and a melt index (I 2 ) from 0.5 g/10 mins to 2.0 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 blown film of claim 1 , wherein the bimodal ethylene-based polymer has a density from 0.910 g/cc to 0.920 g/cc.

3. The blown film of claim 1 , wherein bimodal ethylene-based polymer has a melt index (I 2 ) from 0.7 g/10 mins to 1.8 g/10 mins.

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

5. The blown film of claim 1 , wherein the blown film has average clarity from 97.0% to 99.5%, wherein the average clarity is measured using BYK Gardner Haze-gard as specified in ASTM D 1746.

6. The blown film of claim 1 , wherein the blown film has average gloss from 50 to 75, wherein the average gloss is measured in accordance with ASTM D2457 using a BYK Gardner Glossmeter Microgloss at 45°.

7. The blown film of claim 1 , wherein the blown film has average bulk haze from 6.25% to 13.75%, wherein the average bulk haze is measured in accordance with ASTM D1003 using BYK Gardner Haze-gard.

8. The blown film of claim 7 , wherein the blown film has average dart impact strength from 450 g/mil to 700 g/mil, wherein the average dart impact strength is measured according to ASTM-D 1709-04, Method A.

9. The blown film of claim 1 , wherein the blown film has average puncture from 125.0 ft·lb/in 3 to 175.0 ft·lb/in 3 , wherein the average puncture is measured in accordance with ASTM D5748-95.

10. The blown film of claim 1 , wherein the blown film has average tear in a cross-machine direction from 325 g/mil to 550 g/mil wherein the average tear is Elmendorf Tear Resistance measured in accordance with ASTM D1922.

11. The blown film of claim 1 , wherein the blown film has average tear in a machine direction from 250 g/mil to 350 g/mil, wherein the average tear is Elmendorf Tear Resistance measured in accordance with ASTM D1922.

12. The blown film of claim 1 , wherein the blown film has average secant modulus in a cross-machine direction from 10,000 psi to 39,000 psi, wherein the average secant modulus is measured in accordance with ASTM D882.

13. The blown film of claim 1 , wherein the blown film has average secant modulus in a machine direction from 10,000 psi to 33,500 psi, wherein the average secant modulus is measured in accordance with ASTM D882.

14. The blown film of claim 1 , wherein the blown film has average tensile strength in a cross-machine direction from 7500.0 psi to 8000.0 psi, wherein the average tensile strength is measured in accordance with ASTM D882.

15. The blown film of claim 1 , wherein the blown film has average tensile strength in a cross-machine direction from 8000.0 psi to 8700.0 psi, wherein the average tensile strength is measured in accordance with ASTM D882.

16. The blown film of claim 1 , wherein the blown 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.

17. The blown film of claim 1 , wherein the bimodal ethylene-based polymer has a HDF from 3.0% to 7.5%.

18. The blown film of claim 1 , wherein the bimodal ethylene-based polymer has an I 10 /I 2 ratio from 5.5 to 6.0.

19. The blown film of claim 1 , wherein the bimodal ethylene-based polymer has an SCBD less than or equal to 8° C.

20. The blown film of claim 1 , wherein the bimodal ethylene-based polymer has a ratio of Mw to Mn less than 2.800.

Assignees

• Dow Global Technologies Llc

Inventors

• Hart Kyle E
• Demirors Mehmet
• Gambrel Timothy W
• Fontaine Philip P
• Kalihari Vivek
• Olajide Jr Francis O
• Patel Rajen M

Classifications

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• C08F210/16

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

• C08L23/0815

  with aliphatic 1-olefins containing one carbon-to-carbon double bond · CPC title

• C08F2/001

  Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer (C08F295/00, C08F297/00 take precedence) · CPC title

• C08F2500/05

  Bimodal or multimodal molecular weight distribution · CPC title