Polyethylene compositions

Patent metadata

Field	Value
Publication number	US-12516141-B2
Application number	US-202118003423-A
Country	US
Kind code	B2
Filing date	Feb 5, 2021
Priority date	Jun 30, 2020
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

Embodiments of polyethylene compositions and articles comprising polyethylene compositions are disclosed. The polyethylene compositions may include a first polyethylene fraction area defined by an area in the elution profile in a temperature range of 70° C. to 97° C. via improved comonomer composition distribution (iCCD) analysis method; a first peak in the temperature range of 70° C. to 97° C. in the elution profile; a second polyethylene fraction area defined by an area in the elution profile in a temperature range of 97° C. to 110° C.; and a second peak in the temperature range of 97° C. to 110° C. The polyethylene composition may have a density of 0.935 g/cm3 to 0.955 g/cm3 and a melt index (I2) of 1.0 g/10 minutes to 10.0 g/10 minutes. A ratio of the first polyethylene fraction area to the second polyethylene fraction area may be less than 2.0.

First claim

The invention claimed is:

1 . A polyethylene composition comprising:
a first polyethylene fraction area defined by an area in an elution profile via improved comonomer composition distribution (iCCD) analysis method in a temperature range of 70° C. to 97° C.; a first peak in the temperature range of 70° C. to 97° C. in the elution profile; a second polyethylene fraction area defined by an area in the elution profile in a temperature range of 97° C. to 110° C.; and a second peak in the temperature range of 97° C. to 110° C. in the elution profile; and wherein the polyethylene composition has a density of 0.935 g/cm 3 to 0.955 g/cm 3 , a melt index (I 2 ) of 1.0 g/10 minutes to 10.0 g/10 minutes, and wherein a ratio of the first polyethylene fraction area to the second polyethylene fraction area is less than 2.0.

2 . The polyethylene composition of claim 1 , wherein the polyethylene composition has a molecular weight distribution, expressed as the ratio of the weight average molecular weight to number average molecular weight (Mw (GPC) /Mn (GPC) ) in the range of from 2.0 to 4.5.

3 . The polyethylene composition of claim 1 , wherein the second polyethylene fraction area may comprise from 30% to 80% of the total area of the elution profile.

4 . The polyethylene composition of claim 1 , wherein the polyethylene composition has a comonomer distribution breadth index 50 (CDBI50) of less than or equal to 50%.

5 . The polyethylene composition of claim 1 , wherein the polyethylene composition has an overall molecular weight determined by iCCD (Mw (iCCD) ), the first polyethylene fraction has a first fraction molecular weight determined by iCCD (Mw (iCCD, 70° C.-97° C.) ), and a ratio of the overall molecular weight (Mw (iCCD) ) to the first fraction molecular weight (Mw (iCCD, 70° C.-97° C.) ) is less than 0.9.

6 . The polyethylene composition of claim 1 , wherein the polyethylene composition has a zero shear viscosity ratio of less than 2.0.

7 . The polyethylene composition of claim 1 , wherein the polyethylene composition has an environmental stress crack resistance (ESCR) F50 (10%, A) of greater than 300 hours when measured according to D1693.

8 . A polyethylene composition comprising:
a first polyethylene fraction in a temperature range of 70° C. to 97° C. in an elution profile via improved comonomer composition distribution (iCCD) analysis method, the first polyethylene fraction comprising a first peak, and wherein the first polyethylene fraction has a first fraction molecular weight determined by iCCD (Mw (iCCD, 70° C.-97° C.) ); and a second polyethylene fraction in a temperature range of 97° C. to 110° C. in the elution profile, the second polyethylene fraction comprising a second peak; wherein the polyethylene composition has an overall molecular weight determined by iCCD (Mw (iCCD) ), a density of 0.935 g/cm 3 to 0.955 g/cm 3 , a melt index (I 2 ) of 1.0 g/10 minutes to 10.0 g/10 minutes; and wherein and a ratio of the overall molecular weight (Mw (iCCD) ) to the first fraction molecular weight (Mw (iCCD, 70° C.-97° C.) ) is less than 0.9.

9 . The polyethylene composition of claim 8 , wherein the polyethylene composition has a molecular weight distribution, expressed as the ratio of the weight average molecular weight to number average molecular weight (Mw (GPC) /Mn (GPC) ) in the range of from 2.0 to 4.5.

10 . The polyethylene composition of claim 8 , wherein the second polyethylene fraction area may comprise from 30% to 80% of the total area of the elution profile.

11 . The polyethylene composition of claim 8 , wherein the polyethylene composition has a CDBI50 of less than or equal to 50%.

12 . The polyethylene composition of claim 8 , wherein and a ratio of the first mass fraction to the second mass fraction is less than 2.0.

13 . The polyethylene composition of claim 8 , wherein the polyethylene composition has a zero shear viscosity ratio of less than 2.0.

14 . The polyethylene composition of claim 8 , wherein the polyethylene composition has an ESCR F50 (10%, A) of greater than 300 hours when measured according to D1693.

15 . A method of producing a rotomolded article comprising the polyethylene composition of claim 8 .

Assignees

• Dow Global Technologies Llc

Inventors

• Lugo Elva L
• Biswas Sanjib
• Cooper Russell
• Patel Rajen
• Martin Peter S
• Whited Stephanie M

Classifications

• C08L2203/30

  used for thermoforming · CPC title

• C08L23/0815 Primary

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

• C08F4/64193

  OOOO · CPC title

• C08F2/06

  Organic solvent · 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