Ethylene/alpha-olefin copolymer and method for preparing the same

Patent metadata

Field	Value
Publication number	US-12234307-B2
Application number	US-202017430909-A
Country	US
Kind code	B2
Filing date	Sep 25, 2020
Priority date	Sep 27, 2019
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

The present invention relates to an ethylene/alpha-olefin copolymer having a high weight average molecular weight and narrow molecular weight distribution, and at the same time, a reduced characteristic relaxation time, thereby showing excellent physical properties, and a method for preparing the same.
A resin composition having improved volume resistance and excellent light transmittance may be prepared by using such ethylene/alpha-olefin copolymer. Accordingly, the ethylene/alpha-olefin copolymer may be utilized in various uses in electrical and electronic industrial fields.

First claim

The invention claimed is:

1. An ethylene/alpha-olefin copolymer satisfying the following conditions (a) to (c):
(a) a characteristic relaxation time at 190° C. in shear rate conditions of 0.1 to 500 rad/s, is less than 10.0 millisecond;
(b) a weight average molecular weight is from 40,000 to 150,000 g/mol; and
(c) a molecular weight distribution is from 1.5 to 2.5,
wherein the ethylene/alpha-olefin copolymer has a density from 0.850 to 0.910 g/cc.

2. The ethylene/alpha-olefin copolymer according to claim 1 ,
wherein the characteristic relaxation time is from 1.0 to 9.5 millisecond.

3. The ethylene/alpha-olefin copolymer according to claim 1 , wherein the weight average molecular weight is from 41,000 to 130,000 g/mol.

4. The ethylene/alpha-olefin copolymer according to claim 1 , wherein the molecular weight distribution is from 1.5 to 2.4.

5. The ethylene/alpha-olefin copolymer according to claim 1 , which has a melt index (190° C., 2.16 kg load conditions) from 0.1 to 50 g/10 min.

6. The ethylene/alpha-olefin copolymer according to claim 1 , wherein the alpha-olefin comprises one or more of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene or 1-eicosene.

7. A method for preparing the ethylene/alpha-olefin copolymer of claim 1 , the method comprising:
(S1) a step of preparing a polymerization product of ethylene and an alpha-olefin monomer;
(S2) a step of dissolving the polymerization product in an organic solvent; and
(S3) a step of mixing with an alcohol of 2 to 5 carbon atoms to form the ethylene/alpha-olefin copolymer as a precipitate.

8. The method of claim 7 , wherein the organic solvent is a compound having 7 to 16 carbon atoms.

9. The method of claim 7 , wherein the organic solvent is one or more selected from the group consisting of heptane, octane, isooctane, toluene, xylene and cumene.

10. The method of claim 7 , wherein the alcohol having 2 to 5 carbon atoms is one or more selected from the group consisting of ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, 2-methylpropan-2-ol, pentan-1-ol, pentan-2-ol, pentan-3-ol, 2-methylbutan-2-ol and 3-methylbutan-2-ol.

11. The method of claim 7 , wherein the step (S2) and the step (S3) are alternately repeatedly performed by twice to five times.

12. An encapsulant film comprising an ethylene/alpha-olefin copolymer satisfying the following conditions (a) to (c):
(a) a characteristic relaxation time at 190° C. in shear rate conditions of 0.1 to 500 rad/s, is less than 10.0 millisecond;
(b) a weight average molecular weight is from 40,000 to 150,000 g/mol; and
(c) a molecular weight distribution is from 1.5 to 2.5,
wherein the ethylene/alpha-olefin copolymer has a density from 0.850 to 0.910 g/cc.

13. The encapsulant film according to claim 12 , further comprising one or more of a crosslinking agent, a crosslinking auxiliary agent, a silane coupling agent, an unsaturated silane compound, an amino silane compound, a light stabilizer, a UV absorbent or a thermal stabilizer.

14. A solar cell module comprising the encapsulant film of claim 12 .

Assignees

• Lg Chemical Ltd

Inventors

• Lee Young Woo
• Kim Seul Ki
• Lee Dae Woong
• Lee Jin Kuk
• Lee Eun Jung
• Gong Jin Sam
• Jun Jung Ho
• Lee Jun Hyuk

Classifications

• C08L23/08

  Copolymers of ethene (C08L23/16 takes precedence) · CPC title

• C08L2203/206

  use in coating or encapsulating of electronic parts · CPC title

• C08L23/0815

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

• C08L23/06

  Polyethylene · CPC title

• C08J2323/08

  Copolymers of ethene (C08J2323/16 takes precedence) · CPC title