POLYAMIDE COATED FILTER MEMBRANE, FILTERS, AND METHODS

• US 20190329185A1
• Filed: 04/11/2019
• Published: 10/31/2019
• Est. Priority Date: 04/30/2018
• Status: Active Grant

• Current Assignee: Entegris Incorporated
• Original Assignee: Entegris Incorporated
• Inventors: JABER, Jad Ali, CHENG, Kwok-Shun, LY, Saksatha
• Granted Patent: US 11,413,586 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 2323/30 Cross-linking
• CPC Class Codes: B01D 2325/0283 Pore size
• CPC Class Codes: B01D 2325/04 Characteristic thickness
• CPC Class Codes: B01D 67/0006 by chemical reactions in-situ polymerisation, polycondensation, cross-linking or reaction for manufacturing composite membranes B01D69/125
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 69/107 Organic support material
• CPC Class Codes: B01D 69/1216 Three or more layers
• CPC Class Codes: B01D 69/125 In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction
• CPC Class Codes: B01D 71/261 Polyethylene
• CPC Class Codes: B01D 71/262 Polypropylene
• CPC Class Codes: B01D 71/56 Polyamides, e.g. polyester-amides

Abstract

Described are filter membranes coated with a polyamide, filters and filter cartridges that include the filter membranes, and methods of using and making the filter membranes.

Claims

1. A coated filter membrane comprising:

a porous polymeric filter layer, and

non-porous crosslinked polyamide film coating at a surface of the porous filter layer.

2. The coated filter membrane of claim 1, wherein the polyamide comprises a backbone having a cyclic linkage.

3. The coated filter membrane of claim 2, wherein the cyclic linkage is a di-cyclohexenyl linkage.

4. The coated filter membrane of claim 1, wherein the polyamide is derived from:

caprolactam, hexamethylenediamine adipate, and non-linear monomer selected from a cyclic reactive compound and a di-cyclic reactive compound.

5. The coated filter membrane of claim 4, wherein the non-linear polymer is 4,4-diamino-dicyclohexylmethane adipate.

6. The coated filter membrane of claim 1, wherein the membrane has a dye-binding capacity for methylene blue dye of at least 0.2 micrograms per milligram of the membrane.

7. The coated filter membrane of claim 1, wherein less than 1.0 ng/cm² of magnesium, as measured by inductively coupled plasma mass spectrometry (ICP-MS), is extracted from a sample of the membrane having a diameter of 47 mm and a thickness of 55 microns when the sample is soaked in 15 ml of a 0.1 N solution of HCl for 24 hours.

8. The coated filter membrane of claim 1 further comprising residual free-radical source material.

9. The coated filter membrane of claim 1, wherein the porous polymeric filter layer has a porosity of at least 50 percent.

10. The coated filter membrane of claim 1, wherein the porous polymeric filter layer has a pore size in a range from 0.001 to 10 microns.

11. The coated filter membrane of claim 1 having bubble point in a range from 2 to 400 psi, measured using HFE 7200, at a temperature of 20-25 degrees Celsius.

12. The coated filter membrane of claim 1, wherein the porous polymeric filter layer has a thickness in a range from 5 to 100 microns.

13. The coated filter membrane of claim 1, wherein the porous polymeric filter layer comprises polymer is selected from polyethylene and polypropylene.

14. The coated filter membrane of claim 1, wherein the porous polymeric filter layer is ultra high molecular weight polypropylene.

15. The coated filter membrane of claim 1, wherein the crosslinked polyamide film is resistant to propylene glycol methyl ether (PGME), propylene glycol methylether acetate (PGMEA), or cyclohexanone.

16. A filter cartridge that includes the membrane of claim 1.

17. A filter that includes the membrane of claim 1.

18. A method of using the coated filter membrane of claim 1, the method comprising passing solvent-based liquid through the membrane.

19. The method of claim 18, wherein the liquid comprises solvent selected from propylene glycol methyl ether (PGME), propylene glycol methylether acetate (PGMEA), and cyclohexanone.

20. The method of claim 18, wherein the coated filter membrane removes one or more of Al, Ti, Cr, Mn, Fe, Ni, or Sn from the solvent-based liquid.

21. A method of preparing a coated filter membrane, the method comprising:

coating polymer solution onto a surface of a porous polymeric filter layer, the polymer solution comprising;

polyamide polymer, solvent, and free-radical source material;

causing polyamide of the polymer solution to coagulate on the surface; and

crosslinking the polyamide.

22. The method of claim 21, wherein the solvent is selected from an aliphatic alcohol and a chlorinated hydrocarbon.

23. The method of claim 21, wherein the solvent is selected from methanol, ethanol, propanol, butanol, isopropanol, one or more chlorinated hydrocarbon, and combinations thereof.

24. The method of claim 21, wherein the solvent contains an amount of water.

25. The method of any claim 21, wherein the solvent does not include calcium chloride or formic acid.

26. The method of claim 21, wherein the solvent comprises propanol and up to 20 weight percent water based on total weight solvent.