Electrospun film, method for manufacturing the same and use of such electrospun film

Patent metadata

Field	Value
Publication number	US-12509799-B2
Application number	US-202217898644-A
Country	US
Kind code	B2
Filing date	Aug 30, 2022
Priority date	Mar 22, 2022
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

The invention provides an enhanced electrospun film made from polyvinylidene fluoride (PVDF) and at least one low-melting-point polymer in a ratio of 99.9:0.1-90:10 by weight, and the low-melting-point polymer having a melting point lower than the polyvinylidene fluoride and a softening point in the range of 110-140° C. The enhanced electrospun film exhibits excellent mechanical properties, higher moisture permeability and hydrostatic pressure resistance. The invention further provides a method for manufacturing the enhanced PVDF electrospun film, and use of the enhanced PVDF electrospun film in preparing a waterproof and moisture permeable product.

First claim

What is claimed is:

1 . An electrospun film made by polyvinylidene fluoride (PVDF) and at least one polymer having a melting point lower than the PV DF,
wherein:
the polymer has a softening point in the range of 110-140° C. and is selected from polyvinylidene fluoride;
the electrospun film has water vapor permeability: ≥5,000 g/m 2 ·d; and
the PVDF and the polymer are provided in a ratio of 99.9:0.1-90:10 by weight.

2 . The electrospun film of claim 1 , wherein the polymer is further selected from polyvinyl acetal or any combination thereof.

3 . The electrospun film of claim 2 , wherein the polyvinyl acetal is selected from polyvinyl butyral (PVB) or polyvinyl formal (PVF).

4 . The electrospun film of claim 1 , wherein the electrospun film is obtainable by electrospinning a dope solution comprising the PVDF and the polymer to fabricate a film and heating the film.

5 . The electrospun film of claim 1 , wherein the electrospun film also has parameter(s) selected from:
1) Breaking strength: ≥20 M Pa; and/or 2) Hydrostatic pressure resistance: ≥3,000 mmH 2 O.

6 . The electrospun film of claim 2 , wherein the polyvinyl acetal is selected from polyvinyl butyral (PVB) or polyvinyl formal (PVF).

7 . The electrospun film of claim 1 , wherein the electrospun film also has parameter(s) selected from:
1) Breaking strength: ≥20 M Pa; and/or 2) Hydrostatic pressure resistance: ≥3,000 mmH 2 O.

8 . The electrospun film of claim 1 , wherein the electrospun film also has parameter(s) selected from:
1) Breaking strength: ≥20 M Pa; and/or 2) Hydrostatic pressure resistance: ≥3,000 mmH 2 O.

9 . A method for manufacturing an electrospun film of claim 1 comprising the steps of:
1) Dissolving polyvinylidene fluoride (PVDF) and at least one polymer having a melting point lower than the polyvinylidene fluoride in a solvent to formulate a dope solution having a mass fraction of 10-35%;
2) Electrospinning the dope solution formulated in Step 1) to produce an electrospun film;
3) heating the electrospun film obtained in Step 2) at a predetermined temperature for a predetermined period of time; and
4) Cooling the heated electrospun film.

10 . The method of claim 9 , wherein the polymer has a softening point in the range of 110-140° C.

11 . The method of claim 9 , wherein the polymer is selected from polyvinyl acetal, polyvinylidene fluoride or any combination thereof.

12 . The method of claim 9 , wherein the PVDF and the polymer is provided in a ratio of 99.9:0.1-90:10 by weight.

13 . The method of claim 9 , wherein the step of electrostatic spinning is carried out at a voltage of 15-35 kV and at an advance rate of 0.1-3 ml/h.

14 . The method of claim 9 , wherein the step of heating is carried out at 110-150° C. for 0.5-4 hours.

15 . The method of claim 9 , wherein the solvent is selected from the group consisting of N,N-dimethylformamide, acetone, methanol, ethanol, isopropanol, tetrahydrofuran, dichloromethane, chloroform, dimethyl sulfoxide, ethylene glycol, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, cyclohexane, water and any combination thereof.

16 . A method of manufacturing a waterproof and moisture permeable product, comprising using the electrospun film of claim 1 .

Assignees

• Nanodocks Tech Limited
• Univ City Hong Kong

Inventors

• Hu Jinlian
• Shi Shuo
• Si Yifan
• Wong Siu Wah
• Yuen Muk Fung

Classifications

• D04H1/4318 Primary

  Fluorine series · CPC title

• C08J2327/16

  Homopolymers or copolymers of vinylidene fluoride · CPC title

• D10B2321/06

  polymers of unsaturated alcohols, e.g. polyvinyl alcohol, or of their acetals or ketals · CPC title

• D10B2321/042

  polymers of fluorinated hydrocarbons, e.g. polytetrafluoroethene [PTFE] · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title