Methods for preparing polyurethane film and fabrics comprising the same

Patent metadata

Field	Value
Publication number	US-12522950-B2
Application number	US-202318098860-A
Country	US
Kind code	B2
Filing date	Jan 19, 2023
Priority date	Jan 19, 2023
Publication date	Jan 13, 2026
Grant date	Jan 13, 2026

Abstract

The present invention discloses a method for preparing a polyurethane film, comprising the steps of: i) dissolving polyurethane into a first solvent to form a first solution; ii) dissolving salt into a second solvent to form a second solution; iii) preparing a spinning stock solution by mixing said first solution and said second solution; iv) spinning said spinning stock solution in an electrospinning device to obtain a polyurethane film; v) providing a container to which a third solvent is sprayed; and vi) arranging said polyurethane film in said container for a period of time.

First claim

The invention claimed is:

1 . A method for preparing a polyurethane film, comprising the steps of:
i) dissolving polyurethane into a first solvent to form a first solution; ii) dissolving salt into a second solvent to form a second solution; iii) preparing a spinning stock solution by mixing said first solution and said second solution; iv) spinning said spinning stock solution in an electrospinning device to obtain a polyurethane film; v) providing a container to which a third solvent is sprayed; and vi) arranging said polyurethane film in said container for a period of time.

2 . A method as claimed in claim 1 , wherein said polyurethane is a hydrophobic polyester thermoplastic polyurethane.

3 . A method as claimed in claim 2 , wherein said polyurethane is a ABn-type block linear polymer, wherein A is a polyester and B is a diol.

4 . A method as claimed in claim 3 , wherein said polyester has molecular weight of 1000-6000.

5 . A method as claimed in claim 3 , wherein said diol contains 2-12 linear carbon atoms.

6 . A method as claimed in claim 3 , wherein the chemical structure between the AB segments is diisocyanate.

7 . A method as claimed in claim 6 , wherein the density of said polyurethane is 1.10-1.25 g/cm3.

8 . A method as claimed in claim 1 , wherein said salt is
inorganic salt selected from a group comprising lithium chloride, sodium chloride, potassium chloride, lithium carbonate, sodium carbonate, potassium carbonate, sodium bicarbonate, lithium nitrate, sodium nitrate, and a combination thereof; and/or organic salt selected from a group comprising octadecyltrimethylammonium chloride, tetraethylammonium bromide, and a combination thereof.

9 . A method as claimed in claim 1 , wherein said first solvent, said second solvent, and said third solvent are selected from a group comprising
acetone, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, acetonitrile, ether, ethane, ethanol, formic acid, acetic acid, chloroform, carbon tetrachloride, sulfolane, pyrimidine, formamide, n-hexane, chlorobenzene, dioxane, vinyl glycol, methylcyclohexane, 1,2-Dichloroethylene xylene, cyclohexane, pentane, anisole, butyl acetate, isopropyl acetate, dimethyl alum, N-methylpyrrolidone, dichloromethane, dichloroethyl alkane, chloromethane, benzene, toluene, ethyl acetate, and a combination thereof.

10 . A method as claimed in claim 1 , wherein the weight ratio of said polyurethane in said first solution is 15-30%.

11 . A method as claimed in claim 10 , wherein the weight ratio of said salt in said second solution is 0.1-2%.

12 . A method as claimed in claim 11 , wherein the weight ratio of said first solution to said second solution ranges from 50:0 to 35:15.

13 . A method as claimed in claim 1 , wherein said third solvent is prepared by mixing said first solvent with water.

14 . A method as claimed in claim 13 , wherein said water is deionized water.

15 . A method as claimed in claim 1 , wherein step vi) in claim 1 is carried out at temperature 25-35° C.

16 . A method as claimed in claim 1 , wherein step vi) in claim 1 is carried out at humidity 30%-85% and/or the amount of said third solvent sprayed is 0.5 to 5 ml.

17 . A method as claimed in claim 1 , wherein step iv) in claim 1 is carried out in a single-needle electrospinning device, with at least one of the following parameters:
applied voltage at 20-30 kV, the flow rate of syringe pump at 0.1-1.0 ml/h, the receiving distance at 10-20 cm, the ambient temperature at 23-35° C., the ambient humidity at 35%-85%, the receiving substrate is selected from aluminum foil, oil paper, fabric or non-woven fabric.

18 . A method as claimed in claim 1 , wherein step iv) in claim 1 is carried out in a needle-free electrospinning device, with at least one of the following parameters:
applied voltage at 50-80 kV, the receiving distance at 20-50 cm, the ambient temperature at 23-35° C., the ambient humidity at 35%-85%, the receiving substrate is selected from aluminum foil, oil paper, fabric or non-woven fabric.

19 . A method as claimed in claim 18 , wherein said needle-free electrospinning device is a multi-channel needle-free electrospinning device.

Assignees

• Nanodocks Tech Limited
• Univ City Hong Kong

Inventors

• Hu Jinlian
• Yang Jieqiong
• Shi Shuo
• Si Yifan
• Wong Siu Wah

Classifications

• C08G18/42

  Polycondensates having carboxylic or carbonic ester groups in the main chain · CPC title

• D01D5/0038 Primary

  the fibre formed by solvent evaporation, i.e. dry electro-spinning · CPC title

• D10B2331/10

  polyurethanes · CPC title

• C08J2375/06

  from polyesters · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title