セルローストリアセテートの塩化メチレンーメタノール系溶剤にまる湿式紡糸

抄録

Various dopes of commercial cellulose triacetate flakes of two different DP dissolved in CH₂Cl₂-CH₃OH (9:1) solvent were spun into CH₃OH-CH₂Cl₂ coagulant, and their spinnability curves are shown as the highest and lowest possible reeling speeds vs. CH₂Cl₂ concentration in the coagulant.
The spinnability (the highest possible reeling speed) decreases to minimum and then increases to maximum with increasd CH₂Cl₂ concentration in the coagulant. The minimum lies in 10_??_20 vol % of CH₂Cl₂, and the maximum in 30_??_40 vol %.
The tenacity and the elongation of the spun filament at a certain reeling speed chang also with increase of CH₂Cl₂ concentration in the coagulant. Their minimum and maximum correspond respectively to that of the spinnability. Tenacity takes a maximum at about 80m/min, elongation at 10m/min.
A density and a molecular orientation of the spun filament also change by increasing CH₂Cl₂ concentration in the coagulant, and their minimum or maximum corresponds respectively to that of tenacity, elongation or spinnability.
As the coagulant temperature rises, the maximum or the mininimum spinnability curve corresponds to lower CH₂Cl₂ concentration in the coagulant, the elongation of the spun filament increases, and the cross-sectional shape is more rounded.
The optimum conditions of the spinning in this experiment are considered as follows: triacetate flakes: DP 310, AcOH value 60.6%; dope concentration: 23% in CH₂Cl₂-CH₃OH (9:1); coagulant: CH₂Cl₂ 34 vol % in CH₃OH-CH₂Cl₂, 25°C; reeling speed: 40_??_80m/min.
Tenacity ang elongation of the spun filament at the optimum condition are about 2.5g/d, 20% while a commercial acetate has about 1.5g/d, 24%, Arnel 1.3g/d, 30%.