Low density ethylene-based polymers with high melt strength

• US 9,394,389 B2
• Filed: 03/12/2013
• Issued: 07/19/2016
• Est. Priority Date: 11/20/2012
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Berbee, Otto J., den Doelder, Cornelis F. J., Karjala, Teresa P., Zuercher, Karl, Wang, Jian, Hinrichs, Stefan
• Primary Examiner(s): Nutter, Nathan M
• Application Number:
  US14/434,204
• Publication Number:
  US 20150274856A1
• Time in Patent Office: 1,225 Days
• US Class Current: 1/1
• CPC Class Codes: C08F 110/02 Ethene
• CPC Class Codes: C08F 2500/11 Melt tension or melt strength
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 4/38 Mixtures of peroxy-compounds
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2205/025 containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• CPC Class Codes: C08L 2207/066 LDPE (radical process)
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 23/0869 Acids or derivatives thereof
• CPC Class Codes: C09D 123/06 Polyethene
• CPC Class Codes: C09D 123/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C09D 123/0869 Acids or derivatives thereof

Abstract

The invention provides a composition comprising a first ethylene-based polymer, formed by a high pressure, free-radical polymerization process, and comprising the following properties: a) a Mw(abs) versus I2 relationship: Mw(abs)<A×[(I2)^B], where A=5.00×10² (kg/mole)/(dg/min)^B, and B=−0.40; and b) a MS versus I2 relationship: MS≧C×[(I2)^D], where C=13.5 cN/(dg/min)^D, and D=−0.55.

Claims

1. A composition comprising a first ethylene-based polymer, formed by a high pressure, free-radical polymerization process, and comprising the following properties:

a) a Mw(abs) versus I2 relationship;

Mw(abs)<

A×

[(I2)^B], where A=5.00×

10² (kg/mole)/(dg/min)^B, and B=−

0.40; and

b) a MS versus I2 relationship;

MS≧

C×

[(I2)^D], where C=13.5 cN/(dg/min)^D, and D=−

0.55, and

wherein the first ethylene-based polymer has an I2>

1 g/10 min.

2. The composition of claim 1, wherein the first ethylene-based polymer has a melt index (I2) from 0.3 to less than 4.0 g/10 min.

3. The composition of claim 1, wherein the first ethylene-based polymer has a melt strength greater than, or equal to, 9.0 cN (at 190°

C.).

4. The composition of claim 1, wherein first ethylene-based polymer has a “

weight fraction (w) of molecular weight greater than 10⁶ g/mole, based on the total weight of polymer, as determined by GPC(abs),”

that meets the following relationship;

w<

E×

[(I2)^F], where E=0.110 (dg/min)<sup>−

F</sup>, and F=−

0.38.

5. The composition of claim 1, wherein first ethylene-based polymer is polymerized in at least one tubular reactor.

6. The composition of claim 1, wherein the composition further comprises a second ethylene-based polymer.

7. The composition of claim 6, wherein the composition has a melt index (I2) from 2 to 50 g/10 min.

8. The composition of claim 6, wherein the composition has a density from 0.900 to 0.955 g/cc.

9. The composition of claim 6, wherein the composition has a MS value greater than, or equal to, 2.5 cN (at 190°

C.).

10. The composition of claim 6, wherein the composition comprises greater than 0 wt. % but less than 40 wt. % of the first ethylene-based polymer, based on the sum of the weight of the first and second polymers, and wherein the composition has a G′

value greater than, or equal to, 80 Pa (at 170°

C.).

11. The composition of claim 6, wherein the second ethylene-based polymer comprises at least one comonomer selected from a C3-C20 alpha-olefin, an acrylate, an acetate, a carboxylic acid, carbon monoxide, or an ionomer.

12. The composition of claim 6, wherein the second ethylene-based polymer is selected from an ethylene/alpha-olefin copolymer, a low density polyethylene (LDPE), a high density polyethylene (HDPE), or a combination thereof.

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 fibers, or a tape.

15. A method for forming the composition of any one of claim 1, said method comprising polymerizing ethylene in a reactor configuration that comprises at least one tubular reactor.