# US 8,784,542 B2 · Nanofibre membrane layer for water and air filtration

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,784,542 B2
- Document ID: US8784542B2
- Status: Granted
- Kind: B2
- Application number: 13/376,616
- Filed: 2010-07-15
- Published: 2012-06-07
- Granted: 2014-07-22
- Earliest claimed: 2009-07-15
- Assignees: Dsm IP Assets B.V.
- Applicants: Konraad Albert Louise Hector Dullaert; Marko Dorschu; Arnaud David Henri Chiche
- Inventors: Konraad Albert Louise Hector Dullaert; Marko Dorschu; Arnaud David Henri Chiche
- Web page: https://patentgrep.com/patent/US8784542B2

## CPC

- D01D 5/0038: {the fibre formed by solvent evaporation, i.e. dry electro-spinning}
- B01D 39/1623: {of synthetic origin}
- B01D 69/1071: {Woven, non-woven or net mesh}
- B01D 71/56: Polyamides, e.g. polyester-amides
- D01F 6/60: from polyamides (from polyamino acids or polypeptides D01F6/68)
- D01F 6/90: of polyamides
- B01D 2239/025: comprising nanofibres
- B01D 2239/0631: Electro-spun
- B01D 2323/39: Electrospinning
- B01D 2325/48: Antimicrobial properties
- Y10T 442/681: Spun-bonded nonwoven fabric
- D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The invention relates to a nanofiber membrane layer having a basis weight of 0.01-50 g/m2 and a porosity of 60-95%, comprising a nanoweb made of polymeric nanofibers with a number average diameter in the range of 50-600 nm, consisting of a polymer composition comprising a semicrystalline polyamide having a C/N ratio of at most 5.5. The invention also relates to water and air filtration devices comprising such a nanofiber membrane layer.

## Claims

### Claim 1

A nanofiber membrane layer comprising a nanoweb made of polymeric nanofibers with a number average diameter in the range of 50-600 nm, the polymeric nanofibers consisting of a polymer composition comprising a semicrystalline polyamide having a C/N ratio of at most 5.5, wherein the nanofiber membrane layer has a basis weight of 0.01-50 g/m2, a porosity of 60-95% and a mean pore size in a range from 0.01 to 2 μm.

### Claim 2 (depends on 1)

The nanofiber membrane layer according to claim 1, wherein the basis weight of the nanofiber membrane layer is in the range of 0.01-1.0 g/m2.

### Claim 3 (depends on 1)

The nanofiber membrane layer according to claim 1, wherein the basis weight of the nanofiber membrane layer is between 1 and 20 g/m2.

### Claim 4 (depends on 1)

The nanofiber membrane layer according to claim 1, wherein the number average diameter of the polymeric nanofibers is in the range of 80-300 nm.

### Claim 5 (depends on 1)

The nanofiber membrane layer according to claim 1, wherein the number average diameter of the polymeric nanofibers is in the range of 100-200 nm.

### Claim 6 (depends on 1)

The nanofiber membrane layer according to claim 1, wherein the C/N ratio is in a range of 4.5-5.5.

### Claim 7 (depends on 1)

The nanofiber membrane layer according to claim 1, wherein the semicrystalline polyamide has a melting temperature of at least 260° C.

### Claim 8 (depends on 1)

The nanofiber membrane layer according to claim 1, wherein the semicrystalline polyamide has a melting enthalpy of at least 80 J/g.

### Claim 9 (depends on 1)

The nanofiber membrane layer according to claim 1, wherein the semicrystalline polyamide has a melting temperature of at least 280° C.

### Claim 10 (depends on 1)

A process for making a nanofibre membrane layer according to claim 1, comprising:
(a) electrospinning of a polymer solution comprising a semicrystalline polyamide having a C/N ratio of at most 5.5 dissolved therein on a moving substrate, thereby forming a semi-continuous layer of deposited nanofibers; and
(b) subjecting the deposited layer to an annealing step.

### Claim 11 (depends on 1)

A multilayered membrane construction comprising a first layer consisting of a nanofiber membrane layer according to claim 1, and a second porous layer.

### Claim 12 (depends on 11)

The multilayered membrane construction according to claim 11, wherein the second porous layer consists of a nonwoven web.

### Claim 13 (depends on 11)

The multilayered membrane construction according to claim 11, wherein the second porous layer consists of a second nanofiber membrane layer.

### Claim 14 (depends on 1)

A water or air filtration device comprising a nanofiber membrane according to claim 1.

### Claim 15 (depends on 14)

The water or air filtration device according to claim 14, wherein the nanofiber membrane has a pleated configuration.

### Claim 16 (depends on 1, 14)

A water or air filtration device according to claim 14, which comprises a multilayered membrane structure comprised of the nanofiber membrane according to claim 1, and a second porous layer.

### Claim 17 (depends on 16)

The water or air filtration device according to claim 16, wherein the nanofiber membrane has a pleated configuration.