| 摘要 |
961,400. Cellulose triester filaments. CELANESE CORPORATION OF AMERICA. Nov. 2, 1960 [Nov. 3, 1959; Sept. 27, 1960], No. 37647/60. Heading B5B. A solution of a cellulose triester in an organic solvent is wet-spun, and the filaments, while still swollen, are immersed in a solution or dispersion in a liquid which does not dissolve the filamentary material, of a minor proportion of an organic compound having a molecular chain of at least 14 atoms of which some are carbon or silicon and any remainder are atoms of one or more of the elements carbon, silicon, and oxygen, having a molecular weight of at least 175, a melting point below 50 ‹ C., a boiling point of at least 200‹ C., and a solubility in the cellulose triester of less than 10% by weight, and the filaments wet with the liquid are then dried. Preferably, filaments of cellulose triacetate, especially that having an acetyl value of at least 60%, expressed as acetic acid, are made by extruding a solution thereof, e.g. in methylene chloride or in a mixture of methylene chloride with up to 15% by weight of methanol, into a liquid coagulant having a high swelling effect on the cellulose triacetate, e.g. a methylene chloride and methanol mixture in which the concentration of methylene chloride is equal to 75.25 Œ 5 minus the temperature of the coagulant in ‹ C. The organic compound may be contained in the liquid coagulant, or may be applied as a subsequent bath or spray, e.g. dissolved or dispersed in a washing liquid. Preferably, the organic compound is present in the liquid coagulant, in a concentration of 0.1- 3% by weight. The organic compound may be a hydrocarbon oil having an essentially aliphatic base, especially a white mineral oil with a viscosity at 38‹ C. of 30-400 Saybolt seconds (especially 40-100), a molecular weight of 175 to 400, preferably 200 to 300, an initial boiling point above 200‹ C., preferably above 250‹ C., and a vapour pressure less than 0.1 mm. mercury at 38‹ C. Alternatively, a poly-lower alkylene glycol of molecular weight 600-1000 and ethers and esters thereof may be used. Other compounds specified include higher alkyl esters, e.g. lauryl acetate, glycerides of stearic, oleic, linoleic, ricinoleic, isoricinoloic, dihydroxystearic, arachidic and lignoceric acids, and silicone oils, e.g. polydimethylsiloxane. Desirably, from 0.1-5% by weight of the organic compound is deposited on the filamentary material, which is withdrawn from the coagulant at a linear speed sufficient to draw down the material to a filament denier of less than 2. The filaments wet with the organic compound are then dried, and can be cut into staple fibre having a filament denier of less than 2. Specifications 826,098 and 881,856 are referred to. |
