Vinylidene fluoride resin monofilament and method for producing the same

摘要

A production method of a PVDF monofilament according to the present invention comprises a drawing step of drawing a melt-spun PVDF monofilament; and a dry thermal relaxation treatment step of subjecting the drawn PVDF monofilament to a relaxation thermal treatment in a gas phase at a temperature between 220° C. inclusive and 300° C. and under such conditions that a relaxation rate falls between 4% inclusive and 10% and that a passing time is not more than 5 seconds, thereby obtaining the PVDF monofilament satisfying the relation represented by Eq (1) below;Y>=d3x2x10-7-d2x2x10-4+dx1.17x10-2+73.11 (1)(where d indicates a diameter (mum) and Y a knot strength (kgf/mm2)) and having a knot elongation of not less than 24% and a straight elongation of not less than 30%.