PURPOSE: To easily and profitably obtain the subject fibers by spinning a melt comprising a specific acrylic polymer, a nitroalkane, and a monohydroxyalkanol, drawing the obtained filaments in a constant ratio, thermally treating the filaments and further drawing the filaments in a constant ratio.
CONSTITUTION: This method for forming the melt-spun acrylic fibers comprises forming at an elevated temperature a substantially homogeneous melt consisting essentially of (A) an acrylic polymer containing at least 85 wt.% of recurring acrylonitrile units, (B) approximately 3 to 20 wt.% of a 1-2C nitroalkane based upon the polymer A, (C) approximately 0 to 13 wt.% of a 1-4C monohydroxyalkanol based upon the polymer A, and (D) approximately 12 to 28 wt.% of water based upon the polymer A, extruding the substantially homogeneous melt into a filament-forming zone through an extrusion orifice, drawing the formed filaments in a drawing ratio of 0.6:1 to 6.0:1, thermally treating the drawn filaments at a temperature of 90 to 200°C, and further drawing the acrylic filaments at an elevated temperature in a draw ratio of at least 3:1 to form acrylic filaments having a mean single filament denier of approximately 0.3 to 5.0.
YOON ESU KO
KURISUTOFUAA AARU SUREITAA
JIYOZEFU JII BUENAA
CHI SHII YOON
MOORISU EMU TSUBUITSUKU
