Hollow-fibre membrane having novel structure, and production method therefor

Patent metadata

Field	Value
Publication number	US-9610545-B2
Application number	US-201314418708-A
Country	US
Kind code	B2
Filing date	Mar 29, 2013
Priority date	Dec 21, 2012
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

The present invention relates to a hollow-fibre membrane having a novel structure and to a production method therefor. The hollow-fibre separation membrane of the present invention has an outermost shell surface pore size of between 0.001 and 0.05 μm and a mean pore size of between 0.01 and 0.1 μm while having, in sequence from the outermost shell surface, a dense sponge structure, a finger-like sponge structure and a mixed sponge-bead structure; and, because of this specific triple structure, the invention has outstanding mechanical strength, porosity and water permeability alike while also having a high performance whereby it is possible to eliminate even viruses.

First claim

The invention claimed is:

1. A hollow fiber membrane in which (i) a dense sponge structure having pores with a size of 0.001 to 0.05 μm, (ii) a finger-like sponge structure, and (iii) a sponge-bead mixed structure are formed in the order numbered from the outermost surface of the membrane.

2. The hollow fiber membrane of claim 1 , wherein the pores formed on the outermost surface have a size of 0.001 to 0.01 μm.

3. The hollow fiber membrane of claim 1 , wherein the dense sponge structure has a thickness of 0.01 to 20 μm, the finger-like sponge structure has a thickness of 10 to 100 μm, and the sponge-bead mixed structure has a thickness of 50 to 200 μm.

4. The hollow fiber membrane of claim 1 , wherein the density of the beads contained in the sponge-bead mixed structure (iii) is gradually reduced from the central part to the internal coagulant-contacting part of a membrane.

5. The hollow fiber membrane of claim 1 , wherein the hollow fiber membrane is polyvinylidene fluoride (PVDF)-based membrane.

6. The hollow fiber membrane of claim 1 , wherein the membrane has an ability to remove viruses.

7. A method of preparing the hollow fiber membrane of claim 1 as a continuous process, the method comprising:
(i) supplying a polyvinylidene fluoride (PVDF)-based resin to an extruder;
(ii) supplying a good solvent and a poor solvent to the extruder;
(iii) mixing the supplied materials by using a screw in a cylinder of the extruder; and
(iv) extruding and spinning out the mixed solution.

8. The method of claim 7 , wherein the supplied materials are mixed and molten by screw rotation at a cylinder temperature in step (iii).

9. The method of claim 8 , wherein the temperature of the cylinder is adjusted to 50 to 250° C.

10. The method of claim 8 , wherein the rotation speed of the screw is adjusted to 150 to 300 rpm.

11. The method of claim 7 , wherein the mixed solution in step (iv) is spun out with an internal coagulant.

12. The method of claim 7 , further comprising cooling and solidifying the solution spun out from (iv) using a coagulation bath.

Assignees

• Lg Electronics Inc

Inventors

• Lee Junseok
• Lee Sumin
• Oh Hyunhwan
• Lee Changho
• Kim Minjoung

Classifications

• D01D5/247

  Discontinuous hollow structure or microporous structure · CPC title

• B01D2325/30

  Chemical resistance · CPC title

• B01D69/02 Primary

  characterised by their properties · CPC title

• B01D2323/08

  Specific temperatures applied · CPC title

• B01D69/08 Primary

  Hollow fibre membranes (manufacture of hollow fibres D01D5/24, D01F1/08) · CPC title