Cross-linked polyolefin separator and manufacturing method therefor

Patent metadata

Field	Value
Publication number	US-12462989-B2
Application number	US-201917044026-A
Country	US
Kind code	B2
Filing date	Nov 29, 2019
Priority date	Dec 21, 2018
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

A crosslinked polyolefin separator and a method of making the same are disclosed herein. The method includes mixing a polyolefin, a diluting agent, an initiator, a crosslinking catalyst, and inorganic particles surface treated with an alkoxysilane containing a carbon-carbon double bonded group in an extruder to obtain a mixture, and then reactively extruding the mixture to form an extruded silane-grafted polyolefin composition; molding and orienting the extruded silane-grafted polyolefin composition in the form of an oriented sheet; extracting the diluting agent from the oriented sheet to obtain a porous membrane; thermally fixing the porous membrane to obtain a thermally fixed porous membrane; and crosslinking the thermally fixed porous membrane in the presence of moisture.

First claim

What is claimed is:

1 . A method for manufacturing a crosslinked polyolefin separator, comprising the steps of:
hydrolyzing an alkoxysilane containing a carbon-carbon double bonded group with a solvent to obtain a silanol containing a carbon-carbon double bonded group, wherein the solvent is water, methanol, ethanol or propanol; mixing the silanol containing a carbon-carbon double bonded group with inorganic particles having at least one hydroxy group at 50° C.-80° C. to obtain surface-treated inorganic particles; mixing a polyolefin, a diluting agent, and the surface-treated inorganic particles in an extruder, and then adding an initiator and a crosslinking catalyst to obtain a mixture; extruding the mixture to form an extruded silane-grafted polyolefin composition; molding and orienting the extruded silane-grafted polyolefin composition in a form of an oriented sheet; extracting the diluting agent from the oriented sheet to obtain a porous membrane; thermally fixing the porous membrane to obtain a thermally fixed porous membrane; and crosslinking the thermally fixed porous membrane in the presence of moisture, wherein the inorganic particles are particles of a metal hydroxide, and the metal hydroxide is at least one of aluminum hydroxide, magnesium hydroxide, calcium hydroxide, or boehmite.

2 . The method for manufacturing a crosslinked polyolefin separator according to claim 1 , wherein the polyolefin has a weight average molecular weight of 200,000-1,000,000.

3 . The method for manufacturing a crosslinked polyolefin separator according to claim 1 , wherein in the extruded silane-grafted polyolefin composition, the surface-treated inorganic particles have the silanol containing a carbon-carbon double bonded group coupled thereto via oxygen (O) atoms.

4 . The method for manufacturing a crosslinked polyolefin separator according to claim 1 , wherein in the extruded silane-grafted polyolefin composition, the surface-treated inorganic particles comprise the inorganic particles to which the silanol containing a carbon-carbon double bonded group are chemically bound via oxygen atoms.

5 . The method for manufacturing a crosslinked polyolefin separator according to claim 1 , wherein in the extruded silane-grafted polyolefin composition, the inorganic particles are bound to the silicon atoms of the grafted silane via oxygen (O) atoms.

6 . The method for manufacturing a crosslinked polyolefin separator according to claim 1 , wherein the crosslinking of the thermally fixed porous membrane in the presence of moisture comprises:
moisture-crosslinking the silanol containing a carbon-carbon double bonded group with the polyolefin.

7 . The method for manufacturing a crosslinked polyolefin separator according to claim 1 , wherein the alkoxysilane containing a carbon-carbon double bonded group comprises a compound represented by Chemical Formula 2:

wherein each of R 1 , R 2 and R 3 independently represents a C 1 -C 10 alkoxy group or a C 1 -C 10 alkyl group, with the proviso that at least one of R 1 , R 2 or R 3 represents an alkoxy group; and
R represents a vinyl group, an acryloxy group, a methacryloxy group, or a C 1 -C 20 alkyl group, wherein at least one hydrogen atom of the alkyl group is substituted with a vinyl group, an acryloxy group, or a methacryloxy group.

8 . The method for manufacturing a crosslinked polyolefin separator according to claim 7 , wherein the alkoxysilane containing a carbon-carbon double bonded group is selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, (3-methacryloxypropyl) trimethoxysilane, (3-methacryloxypropyl) triethoxysilane, vinylmethyl dimethoxysilane, vinyl-tris(2-methoxyethoxy) silane, vinylmethyldiethoxysilane, and a mixture thereof.

Assignees

• Lg Chemical Ltd

Inventors

• Ryu Bi-Oh
• Lee Joo-Sung
• Bae Won-Sik

Classifications

• B01D71/262

  Polypropylene · CPC title

• B01D71/261

  Polyethylene · CPC title

• B01D67/00931

  by introduction of specific groups after membrane formation, e.g. by grafting · CPC title

• B01D71/70

  Polymers having silicon in the main chain, with or without sulfur, nitrogen, oxygen or carbon only · CPC title

• B01D71/024

  Oxides · CPC title