A process for the manufacture of artificial high-tenacity threads of regenerated cellulose, and the threads thus obtained

摘要

991,156. Spinning viscose. ONDERZOEKINGSINSTITUUT RESEARCH N.V. Oct. 28, 1963 [Oct. 30, 1962], No. 42342/63. Heading B5B. Regenerated cellulose filaments having an all-skin structure are made by extruding viscose, in the presence of at least one regeneration retardant, into a spinning bath containing sulphuric acid, sodium sulphate and 3-10% by weight of zinc sulphate, stretching the freshlyspun filaments (e.g. 90-100%) in a sulphuric acid bath containing 1.5-10% by weight of acid and maintained at a temperature of 85- 98‹ C., adjusting the pH of the running wet filaments to 5-8.5, collecting the stretched filaments into yarn packages and drying the filaments for not more than 20 minutes. The pH may be adjusted by washing with water or with an aqueous solution of sodium carbonate, bicarbonate or sulphate, or aqueous ammonia. pH adjustment may be carried out by passing the filaments through a bath before collection or by spraying the treating liquid on to a roller over which the filaments pass before collection. The treated filaments are collected on a spool, or in a spinning pot or perforated basket. The filament may be dried by placing the yarn package in a high-frequency electric field or by unwinding the collected filaments and passing them through an air tunnel or over a heated roll. The filaments may be under tension while drying, or may be subjected to further stretch e.g. 10% and then dried. The regeneration retardant, which may be present in the viscose, or in the spinning bath, or in both, may be an amine, a quaternary ammonium compound, a carbaminate, a polyethylene glycol, or an ether of formula RO(CH 2 CH 2 O) n R1, where R is alkyl or aryl and R1 is hydrogen, alkyl or aryl. Preferably the viscose also contains a cation-active nitrogen compound which counteracts fouling of the spinneret orifices. Such compounds may have formula where R is an aliphatic chain of 8-24 carbon atoms, and + y = 5-25, neither being o. The viscose preferably contains at least 0.5% of each of the regeneration retardant and the nitrogen compound. The latter may also be incorporated into the spinning bath.