| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonwoven fabric excellent in collecting properties, insulation properties (short circuit resistance), liquid absorbing and penetrating properties, liquid retention properties, adsorption properties, sound absorption properties, wiping properties, heat insulation properties, heat shield properties, and flame proofness, and capable of being suitably used over a wide range of applications such as a battery, a separator of a capacitor, a film material for a fuel battery; a sound absorption material, a heat insulation material, a flame proofing material, a heat shielding material, protective clothing, an adsorption material, a moisture-permeable and waterproof sheet, wall paper, a paper screen, a cleaner, a liquid or gas filter, and to provide a method for producing the same.SOLUTION: A nonwoven fabric comprises a plurality of continuous fibers. The plurality of continuous fibers have an average fiber diameter of 0.1-5 μm and comprise fibers having a fiber diameter of 5 μm or greater. The fiber having a fiber diameter of 5 μm or greater has a plurality of holes having a size of one ten-thousandth of the fiber diameter on the fiber surface. The nonwoven fabric has an average apparent density of 0.05-2.0 g/cm, an average void diameter of 0.1-10 μm, and a maximum void diameter of 50 μm or smaller. The method for producing a nonwoven fabric includes: (1) ejecting a polymer solution from a plurality of ejection holes having a small diameter; (2) effecting an air flow discharged from the outside of the ejection holes to elongate the ejected polymer solution or to make the diameter smaller; (3) then, jetting or spraying a coagulation liquid comprising 100/0-85/5 of water/an amide-based polar solvent (weight ratio) having a temperature of 10°C or higher by compressed air to solidify the ejected polymer solution, thereby turning it into a plurality of continuous fibers having an average fiber diameter of 0.1-5 μm and comprising fibers having a fiber diameter of 5 μm or greater, in which the fiber having a fiber diameter of 5 μm or greater has a plurality of holes having one ten-thousandth of the fiber diameter on the fiber surface; and (4) collecting the fibers to make a nonwoven fabric. |
