| 摘要 |
PURPOSE:To prevent the collapse of a hollow part by enhancing the balance between a water pervious speed and the transmission coefficient of a solute, by using not only phosphoric ester as the solvent of cellulose acetate but also a water-insoluble or hardly water-soluble substance as a hollow yarn spinning internal coagulation liquid. CONSTITUTION:A hollow yarn membrane is prepared from a cellulose acetate polymer such as cellulose diacetate or cellulose triacetate. Especially, cellulose acetate with acetification degree of about 54% is pref. As a solvent for a spinning raw solution, phosphoric ester such as triethyl phosphate or trimethyl phosphate is used. As an internal coagulation liquid for spinning, it is necessary to use a water-insoluble or hardly water-soluble substance such as liquid paraffin, isopropyl myristate or ispropyl palmitate.
|
