Polyethylene formulations with improved barrier and environmental stress crack resistance

Patent metadata

Field	Value
Publication number	US-2023106941-A1
Application number	US-202217961046-A
Country	US
Kind code	A1
Filing date	Oct 6, 2022
Priority date	Jun 14, 2018
Publication date	Apr 6, 2023
Grant date	—

Abstract

Polyethylene formulations and articles produced therefrom, comprise a multimodal high density polyethylene (HDPE) composition, and 0.1 ppm to 300 ppm of a nucleating agent, wherein the multimodal HDPE composition comprises a density of 0.940 g/cm3 to 0.970 g/cm3 when measured according to ASTM D792, and a melt index (I2) of 0.1 g/10 min. to 10.0 g/10 min. when measured according to ASTM D1238 at 190° C. and a 2.16 kg load, and wherein the multimodal HDPE composition comprises an infrared cumulative detector fraction (CDFIR) of greater than 0.27 and an infrared cumulative detector fraction to light scattering cumulative detector fraction ratio (CDFIR/CDFLS) from 0.7 to 2.0.

First claim

1 . A polyethylene formulation comprising:
a bimodal high density polyethylene (HDPE) composition, and 0.1 ppm to 300 ppm of a nucleating agent, relative to million parts of polyethylene formulation, wherein the bimodal HDPE composition comprises a density of 0.940 g/cm 3 to 0.970 g/cm 3 when measured according to ASTM D792, and a melt index (I 2 ) of 0.1 g/10 min. to 10.0 g/10 min. when measured according to ASTM D1238 at 190° C. and σ2.16 kg load, wherein the bimodal HDPE composition comprises an infrared cumulative detector fraction (CDF IR ) of greater than 0.27 and an infrared cumulative detector fraction to light scattering cumulative detector fraction ratio (CDF IR /CDFLs) from 0.7 to 2.0,
wherein the CDF IR is computed by measuring the area fraction of an IR 5 measurement channel (IR) detector chromatogram less than 15,000 g/mol molecular weight using Gel Permeation Chromatography (GPC); and
wherein the CDFLs is computed by measuring the area fraction of a low angle light scattering (LALLS) detector chromatogram greater than 1,000,000 g/mol molecular weight using GPC.

2 . The polyethylene formulation of claim 1 , wherein the bimodal HDPE composition comprises an infrared cumulative detector fraction to a light scattering cumulative detector fraction ratio (CDF IR /CDF LS ) from 1.1 to 2.0.

3 . The polyethylene formulation of claim 2 , wherein the bimodal HDPE composition comprises a first ethylene polymer component and a second ethylene polymer component, wherein the first ethylene polymer component has a higher density than the second ethylene polymer component as determined from the following equation:

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and wherein the first ethylene polymer component has a lower weight-average molecular weight than the second ethylene polymer component according to GPC.

4 . The polyethylene formulation of claim 3 , wherein the bimodal HDPE composition comprises 40 wt. % to 80 wt. % of the first ethylene polymer component, and 20 wt. % to 60 wt. % of the second ethylene polymer component.

5 . The polyethylene formulation of claim 1 , wherein the nucleating agent comprises an organic nucleating agent.

6 . The polyethylene formulation of claim 1 , wherein the nucleating agent comprises metal carboxylates, metal aromatic carboxylate, hexahydrophthalic acid metal salts, stearates, organic phosphates, bisamides, sorbitols, or mixtures thereof

7 . The polyethylene formulation of claim 1 , wherein the I 2 is from 0.5 g/10 min. to 5.0 g/10 min and the density is from 0.950 g/cm 3 to 0.960 g/cm 3 .

8 . The polyethylene formulation of claim 1 , comprising 10 ppm to 300 ppm of a nucleating agent.

9 . The polyethylene formulation of claim 1 , comprising 10 ppm to 150 ppm of a nucleating agent.

10 . The polyethylene formulation of claim 1 , comprising 0.1 ppm to 75 ppm of a nucleating agent.

11 . The polyethylene formulation of claim 1 , wherein 75 parts per million (ppm) of the nucleating agent increases the crystallization temperature (T σ ) of the polyethylene formulation by at least about 1.0° C. as measured according to differential scanning calorimetry (DSC).

12 . An article produced from the polyethylene formulation of claim 1 , wherein the article is a molded article or fabricated article.

13 . The article of claim 12 , wherein the article provides an oxygen transmission rate improvement of at least about 15% when compared to similar articles that do not comprise the nucleating agent.

14 . The article of claim 12 , wherein the article comprises a closure device.

15 . A compression or an injection molded article comprising the polyethylene formulation of — claim 1 .

16 . The polyethylene formulation of claim 1 , wherein the I 2 is from 0.5 g/10 min. to 10.0 g/10 min.

17 . The polyethylene formulation of claim 1 , wherein the I 2 is from 1 g/10 min. to 5.0 g/10 min.

18 . The polyethylene formulation of claim 1 , wherein the CDF IR is at least 0.30.

19 . The polyethylene formulation of claim 1 , wherein the CDF IR is at least 0.32.

Assignees

• Dow Global Technologies Llc

Inventors

• Lin Yijian
• Sugden John L
• Kapur Mridula Babli
• Gillespie David T

Classifications

• C08L2205/24

  Crystallisation aids · 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

• C08L23/06 Primary

  Polyethylene · CPC title

• C08K5/053

  Polyhydroxylic alcohols · CPC title

• C08K5/521

  Esters of phosphoric acids, e.g. of H3PO4 · CPC title