Ethylene/alpha-olefin copolymer having excellent environmental stress crack resistance

Patent metadata

Field	Value
Publication number	US-10815324-B2
Application number	US-201716088661-A
Country	US
Kind code	B2
Filing date	Nov 2, 2017
Priority date	Nov 15, 2016
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

Provided is an ethylene/alpha-olefin copolymer having excellent environmental stress crack resistance.

First claim

The invention claimed is:

1. An ethylene/alpha-olefin copolymer, wherein
a weight average molecular weight is 50,000 g/mol to 250,000 g/mol,
a molecular weight distribution (Mw/Mn) is 4 to 20,
a density is 0.950 g/cm 3 to 0.965 g/cm 3 ,
a melt flow rate ratio (MFR 5 /MFR 2.16 ) as measured at 190° C. according to ASTM 1238 is 3 to 10, and
environmental stress crack resistance as measured according to ASTM D1693-B is 150 hours to 350 hours.

2. The ethylene/alpha-olefin copolymer of claim 1 , wherein the weight average molecular weight is 180,000 g/mol to 220,000 g/mol.

3. The ethylene/alpha-olefin copolymer of claim 1 , wherein the molecular weight distribution (Mw/Mn) is 10 to 15.

4. The ethylene/alpha-olefin copolymer of claim 1 , wherein the melt flow rate ratio is 5 to 8.

5. The ethylene/alpha-olefin copolymer of claim 1 , wherein the environmental stress crack resistance is 200 hours to 400 hours.

6. The ethylene/alpha-olefin copolymer of claim 1 , wherein
crack resistance is 100 hours or more, the crack resistance is a time at which a water pressure begins to decrease, when the water pressure of 5 bar is applied to the inside of a cap obtained by injection-molding of the ethylene/alpha-olefin copolymer while the cap is immersed in a bath containing a 5% igepal solution, wherein the cap is a 28 mm cap according to PET standard PCO 1881.

7. The ethylene/alpha-olefin copolymer of claim 1 , wherein
the alpha-olefin is one or more selected from the group consisting of 1-propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1 -pentene, 1-octene, 1-decene, 1-docene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, and mixtures thereof.

Assignees

• Lg Chemical Ltd

Inventors

• Sun Soon Ho
• Bae Yo Han
• Lee Hyeong Il
• Choi Yi Young
• Hong Bog Ki
• Lee Sung Min
• Kim Sun Mi
• Park Jin Young

Classifications

• C08F2420/07

  Heteroatom-substituted Cp, i.e. Cp or analog where at least one of the substituent of the Cp or analog ring is or contains a heteroatom · CPC title

• C08F2410/06

  Catalyst characterized by its size · CPC title

• C08F2500/18

  Bulk density · CPC title

• C08F2500/13

  Environmental stress cracking resistance · CPC title

• C08F210/02 Primary

  Ethene · CPC title