Bimodal polyethylene homopolymer composition

Patent metadata

Field	Value
Publication number	US-12234347-B2
Application number	US-202017754006-A
Country	US
Kind code	B2
Filing date	Sep 22, 2020
Priority date	Sep 26, 2019
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

A nucleating agent-free and LLDPE-free polyolefin composition for making films with enhanced barrier properties against water vapor and oxygen gas. Related aspects include formulations, manufactured articles, films, and methods.

First claim

The invention claimed is:

1. A bimodal polyethylene homopolymer composition consisting essentially of a higher molecular weight polyethylene homopolymer component (HMW component) and a lower molecular weight polyethylene homopolymer component (LMW component); wherein the composition has a density from 0.961 to 0.980 gram per cubic centimeter (g/cm 3 ); a melt index (I 2 ) from 0.2 to 2.0 gram per 10 minutes (g/10 min.); a gel permeation chromatography (GPC) resolved bimodality from Log (M) 4.01 to Log (M) 4.99; an amount of the HMW component from 30 to 70 weight percent (wt %) based on the combined weight of the HMW and LMW components; and a number-average molecular weight (M n ) from 3,000 to 4,990 grams per mole (g/mol).

2. The composition of claim 1 wherein the composition has a density from 0.961 to 0.974 g/cm 3 ; a melt index (I 2 ) from 0.25 to 1.6 g/10 min.; a GPC resolved bimodality from Log (M) 4.21 to Log (M) 4.75; an amount of the HMW component from 30 to 60 wt % based on the combined weight of the HMW and LMW components; and an M n from 3,060 to 4,790 g/mol.

3. The composition of claim 1 wherein the composition has any one of properties (i) to (iv): (i) a melt flow ratio (I 21 /I 2 ) from 45 to 100; (ii) a weight-average molecular weight (M w ) from 101,000 to 180,000 g/mol; (iii) a molecular weight distribution (M w /M n ) from 21 to 59; and (iv) a z-average molecular weight (M z ) from 501,000 to 999,000 g/mol.

4. The composition of claim 1 wherein the HMW component has any one of properties (i) to (iii): (i) an M n from 45,000 to 99,000 g/mol; (ii) an M w from 160,000 to 390,000 g/mol; and (iii) both (i) and (ii); or wherein the LMW component has any one of properties (iv) to (vi): (iv) an M n from 1,500 to 2,400 g/mol; (v) an M w from 5,000 to 10,000 g/mol; and (vi) both (iv) and (v).

5. A method of making the bimodal polyethylene homopolymer composition of claim 1 , the method consisting essentially of contacting ethylene with a bimodal catalyst system in the presence of molecular hydrogen (H 2 ) at a hydrogen-to-ethylene (H 2 /C 2 ) molar ratio from 0.005 to 0.025 in a single gas phase polymerization reactor containing a floating bed of resin at a temperature of 90° to 105° C.; wherein the contacting of the ethylene with the bimodal catalyst system is performed in the absence of a (C 3 -C 20 ) olefin comonomer; and wherein the bimodal catalyst system consists essentially of a substantially single site non-metallocene catalyst, optionally disposed on a support material, and a metallocene catalyst, optionally disposed on a support material; thereby concurrently making the HMW and LMW components so as to make the bimodal polyethylene homopolymer composition.

6. A formulation consisting essentially of the bimodal polyethylene homopolymer composition of claim 1 and at least one additive.

7. A manufactured article consisting essentially of a shaped form of the formulation of claim 6 .

8. A method of making a manufactured article, the method consisting essentially of shaping a melt of the formulation of claim 6 and then cooling the shaped melt so as to make a manufactured article consisting essentially of a shaped form of the formulation.

9. An extruded film made by extruding a melt of the formulation of claim 6 in a film extrusion process to give a solid film consisting essentially of the formulation restricted in one dimension.

10. A method of making an extruded film, the method consisting essentially of extruding a melt of the formulation of claim 6 in a film extrusion process to give a solid film consisting essentially of the formulation restricted in one dimension.

11. A method of protecting a moisture-sensitive and/or oxygen-sensitive material in need of such protection, the method comprising hermetically sealing the moisture-sensitive and/or oxygen-sensitive material inside a package consisting essentially of the extruded film of claim 9 to give a sealed package, thereby protecting the moisture-sensitive and/or oxygen-sensitive material from water and/or oxygen gas that is/are located outside the sealed package.

12. A sealed package consisting essentially of the extruded film of claim 9 and the moisture-sensitive and/or oxygen-sensitive material that is disposed inside the sealed package, which is hermetically sealed by the extruded film.

Assignees

• Univation Tech Llc

Inventors

• Borse Nitin
• Chandak Swapnil B
• Bafna Ayush A
• Kuhlman Roger L
• Wieliczko Joel D
• Szul John F
• He Chuan C
• Lester Charles D

Classifications

• C08L2207/062

  HDPE · CPC title

• C08F110/02

  Ethene · 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

• C08L2201/14

  Gas barrier composition · CPC title

• C08L23/06 Primary

  Polyethylene · CPC title