Low density ethylene-based polymer compositions with high melt strength and mid-high density control

Patent metadata

Field	Value
Publication number	US-10538652-B2
Application number	US-201715820083-A
Country	US
Kind code	B2
Filing date	Nov 21, 2017
Priority date	May 22, 2013
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

The invention provides a composition comprising a first ethylene-based polymer, formed by a high pressure, free-radical polymerization process, and a second ethylene-based polymer, formed by a high pressure, free-radical polymerization process, such composition comprising the following properties:
a) a melt index (I2) from 2.0 to 10 dg/min; b) a density from 0.922 to 0.935 g/cc; and wherein the second ethylene-based polymer is present in an amount from 60 to 95 weight percent, based on the sum of the weight of the first polymer and the second polymer; and wherein the second ethylene-based polymer has a density greater than, or equal to, 0.924 g/cc; and wherein the first ethylene-based polymer has a melt index less than 2.5 dg/min.

First claim

The invention claimed is:

1. A composition comprising a first ethylene-based polymer, formed by a high pressure, free-radical polymerization process, and a second ethylene-based polymer, formed by a high pressure, free-radical polymerization process, such composition comprising the following properties:
a) a melt index (I2) from 2.0 to 10 dg/min;
b) a density from 0.922 to 0.935 g/cc; and
wherein the second ethylene-based polymer is present in an amount from 60 to 95 weight percent, based on the sum of the weight of the first ethylene-based polymer and the second ethylene-based polymer; and
wherein the second ethylene-based polymer has a density greater than, or equal to, 0.924 g/cc; and
wherein the first ethylene-based polymer has a melt index less than 2.5 dg/min; and
wherein the first ethylene-based polymer is formed in a tubular reactor comprising at least three reaction zones.

2. The composition of claim 1 , wherein the first ethylene-based polymer has a melt index less than 2.0 dg/min.

3. The composition of claim 1 , wherein the second ethylene-based polymer is present in an amount from 70 to 92 weight percent, based on the sum of the weight of the first polymer and the second polymer.

4. The composition of claim 1 , wherein the first ethylene-based polymer has a Melt Strength greater than, or equal to, 15 cN.

5. The composition of claim 1 , wherein the second ethylene-based polymer has a melt index from 2.0 to 50 dg/min.

6. The composition of claim 1 , wherein the composition has a hexane extractable content less than 5.5 wt %.

7. The composition of claim 1 , wherein the second ethylene-based polymer has a melt index from 3.0 to 30 dg/min.

8. The composition of claim 1 , wherein the composition has a hexane extractable content less than 2.6 wt %.

9. The composition of claim 1 , wherein the first ethylene-based polymer and the second ethylene-based polymer each independently has a hexane extractable content less than, or equal to, 2.6 wt %.

10. The composition of claim 1 , wherein each polymer component of the composition independently has a hexane extractable content less than, or equal to, 2.6 wt %.

11. The composition of claim 1 , wherein the composition has a melt index (I2) from 2.5 to 10 dg/min.

12. The composition of claim 1 , wherein the composition has a density from 0.922 to 0.932 g/cc.

13. An article comprising at least one component formed from the composition of claim 1 .

14. The article of claim 13 , wherein the article is a coating, a film, a foam, a laminate, a fiber, or a tape.

15. A method for forming the composition of claim 1 , said method comprising mixing the first ethylene-based polymer and the second ethylene-based polymer.

16. A method for forming the composition of claim 1 , said method comprising separately feeding the first ethylene-based polymer and the second ethylene-based polymer into an extrusion system.

Assignees

• Dow Global Technologies Llc

Inventors

• Den Doelder Cornelis F J
• Zuercher Karl
• Berbee Otto J
• Wang Jian
• Karjala Teresa P

Classifications

• C08L2207/066

  LDPE (radical process) · CPC title

• C08J9/0061

  characterized by the use of several polymeric components · CPC title

• C08J2323/06

  Polyethene · CPC title

• C08L2203/16

  used for films · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title