| 摘要 |
Regenerated cellulose filaments, yarns, films, bands and ribbons of improved properties are obtained by extruding or casting viscose in an aqueous sulphuric acid precipitating bath, containing 1-15 per cent by weight of zinc sulphate, in the presence of a diamine, as defined below, in an amount of preferably not more than 1 per cent by weight of the bath or of the viscose. The diamine must contain a total of at least 3 carbon atoms, and its amino nitrogen atoms must be attached only to aliphatic carbon atoms and must be separated by at least two aliphatic carbon atoms which may be substituted or unsubstituted, and it must be soluble in 6 per cent aqueous sodium hydroxide to the extent of at least 0.2 per cent by weight. One or both nitrogen atoms of the diamine may be substituted by monovalent alkyl or cycloalkyl radicals of 1-6 carbon atoms. The carbon atoms separating the amino groups may have alkoxy, heterocyclic, aromatic or dialkylamino side chains. Specified diamines, which may be employed in admixture, are trimethylene-, tetramethylene-, pentamethylene-, hexamethylene-, octamethylene- and 1 : 4-cyclohexane-diamines; piperazine and N,N1-dimethyl - piperazine; 3 - methoxy - hexamethylene-, 3-dimethylamino-hexamethylene-, 3 - ethoxyethoxy - hexamethylene - and 4,4 - dimethylhexamethylene diamines; N-methyl-trimethylene-, N-hexyltrimethylene-, N-cyclohexyltetramethylene-, N - butyl - hexamethylene- and N-methylnonamethylenediamines; N,N-dimethyltrimethylene-, N,N-diethyl - 1 : 4 - cyclohexane -, N,N1 - dimethylethylene -, N,N1 - diisobutylhexamethylene-, N,N1 - diallylhexamethylene - and N,N,N1,N1-tetraethylhexamethylene diamines. The coagulating bath also contains sodium sulphate and, if desired, ferrous, manganese, magnesium, nickel and chromic sulphates may be added. The products obtained have a reduced or eliminated skin-and-core effect, a low secondary swelling and a non-crenulated surface. The process permits "green" viscose to be spun. Spinning may be effected with the spinning tubes described in Specification 712,623. |
