Films made from polyethylene compositions and processes for making same

Patent metadata

Field	Value
Publication number	US-11046796-B2
Application number	US-201816632240-A
Country	US
Kind code	B2
Filing date	Jun 29, 2018
Priority date	Aug 4, 2017
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

The present disclosure provides films made of polyethylene (PE) compositions. In at least one embodiment, a film includes a polyethylene composition, comprising: ethylene content and from 0 to 25 mol % of C 3 -C 40 olefin comonomer content, based upon the total weight of the polyethylene composition, the polyethylene composition having a total internal plus terminal unsaturation greater than 0.7 unsaturations per 1000 carbon atoms, the film having: an Elmendorf Tear value in the machine direction of from 10 g/mil to 300 g/mil, and a Dart Drop Impact of from 100 g/mil to 800 g/mil. In at least one embodiment, the present disclosure provides for processes to make a film.

First claim

What is claimed is:

1. A film comprising:
a polyethylene composition, comprising:
an ethylene content and from 0 to 25 mol % of a C 3 -C 40 olefin comonomer content, based upon the total molar content of the polyethylene composition, the polyethylene composition having a total internal plus terminal unsaturation greater than 0.7 unsaturations per 1000 carbon atoms, and further having terminal unsaturations of 50% or more of the total unsaturations,

wherein the film has:
an Elmendorf Tear value in the machine direction of from 10 g/mil to 300 g/mil, and
a Dart Drop Impact of from 100 g/mil to 1,100 g/mil.

2. The film of claim 1 , wherein the polyethylene composition has a density from 0.900 to 0.940 g/cc.

3. The film of claim 1 , wherein the polyethylene composition has a g′vis of 0.97 or greater.

4. The film of claim 1 , wherein the polyethylene composition has a g′vis of 0.99 or greater.

5. The film of claim 1 , wherein the polyethylene composition has a T 75 -T 25 greater than 20° C.

6. The film of claim 1 , wherein the polyethylene composition has a vinyl content of greater than 50% of the total unsaturation.

7. The film of claim 1 , wherein the polyethylene composition has a terminal unsaturation: internal saturation ratio of from 1 to 4.

8. The film of claim 1 , wherein the polyethylene composition has an RCI,m of from 50 to 100.

9. The film of claim 1 , wherein the polyethylene composition comprises from 6 mol % to 10 mol % of comonomer content.

10. The film of claim 1 , wherein the C 3 -C 40 olefin comonomer is hexene.

11. The film of claim 1 , wherein the polyethylene composition has an Mw/Mn value of from 6 to 9.

12. The film of claim 1 , wherein the polyethylene composition has a melt index ratio (I 21 /I 2 ) of from 20 to 40.

13. The film of claim 1 , wherein the film has one or more of the following properties:
an average of the MD and TD 1% secant modulus of from 35,000 psi to 60,000 psi;
a Dart Drop Impact of from 400 g/mil to 1,000 g/mil;
an Elmendorf Tear value in the machine direction of from 50 g/mil to 250 g/mil;
an Elmendorf Tear value in the transverse direction of from 400 g/mil to 1,000 g/mil;
a Tensile Strength in the machine direction of from 3,000 psi to 12,000 psi;
a Tensile Strength at Yield in the machine direction of from 500 psi to 3,000 psi;
a Tensile Strength at Yield in the transverse direction of from 1,000 psi to 3,000 psi; and
an Elongation at Break in the machine direction of from 200% to 600%.

14. The film of claim 1 , wherein the film has a haze of from about 7% to about 11%.

15. The film of claim 1 , wherein the film is a blown film or a cast film.

16. A process for forming the film of claim 1 , the process comprising:
extruding the polyethylene composition through a die at a die rate of from 0.3 kg/mm-hr to 2 kg/mm-hr and obtaining the film.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Li Dongming
• Fiscus David M
• Stevens Kevin A
• Lue Ching-Tai
• Holtcamp Matthew W

Classifications

• B29K2023/08

  Copolymers of ethylene (B29K2023/16 takes precedence) · CPC title

• C08F2500/00

  Characteristics or properties of obtained polyolefins; Use thereof · CPC title

• C08J2323/08

  Copolymers of ethene (C08J2323/16 takes precedence) · CPC title

• C08F10/02

  Ethene · CPC title

• B29D7/01

  Films or sheets · CPC title