Monofilament and method for producing same

Abstract

To provide a monofilament of PA4, which has a low density. The monofilament of polyamide 4 in an embodiment of the present invention has a density of 1.230 g/cm 3 or less. A method for producing a monofilament of polyamide 4 according to an embodiment of the present invention includes: melt-extruding polyamide 4; and cooling a melted and extruded matter of the polyamide 4 obtained by the melt-extruding process, at −10° ° C. or lower by using a nonpolar solvent.

1 . A monofilament of polyamide 4, the monofilament having a density of 1.230 g/cm 3  or less. 
     
     
         2 . The monofilament according to  claim 1 , wherein the monofilament has a diameter of 1 mm or less. 
     
     
         3 . A method for producing a monofilament, the method comprising:
 melt-extruding polyamide 4, and   cooling a melted and extruded fibrous matter of the polyamide 4 obtained by the melt-extruding process, at −10° C. or lower by using a nonpolar solvent.   
     
     
         4 . The method for producing a monofilament according to  claim 3 , wherein the nonpolar solvent contains at least one solvent selected from the group consisting of silicone oil, hexane, nonane, decane, ethylcyclohexane, isopropylcyclohexane, toluene, and p-cymene. 
     
     
         5 . The method for producing a monofilament according to  claim 3 , further comprising drawing the monofilament cooled in the cooling process.