GB1069500A - Improvements in viscose spinning - Google Patents

Abstract

1,069,500. Spinning viscose. BEAUNIT CORPORATION. Dec. 23, 1963, No. 50728/63. Heading B5B. Viscose containing a polyalkylene glycol, or a derivative thereof, said glycol having an average molecular weight of at least 400 and a water-soluble hydroxy fatty acid is extruded into an acid spin bath. The polyalkylene glycol may be polyethylene glycol, polypropylene glycol or mixed polyethylene-polypropylene glycol, said glycols having an average molecular weight of 400 to about 9000. The hydroxy fatty acid may contain 2 to 6 carbon atoms in the molecule and the hydroxyl group is preferably in the alpha position. The viscose may have a salt point of about 7À5 to about 9À0. The modifiers may be dispersed and/or dissolved in both the viscose and the spin bath. The polyglycol modifier only may be added to the viscous while the spin bath contains sufficient proportions of both modifiers, the proportion of hydroxy fatty acid added to the spin bath to ensure the presence in the bath of sufficient of this modifier to retard greatly the degradation of the polyalkylene glycol modifier introduced into the bath by the spinning operation. The viscose is preferably " green " or substantially unmatured. Very high molecular weight polyalkylene glycol modifiers, e.g. of molecular weight 20,000, are not particularly efficient. In the examples, the modifiers used are " Carbowax 4000" (a polyethylene glycol having an average molecular weight of about 3300) and hydroxyacetic acid and the spin bath contains sulphuric acid, sodium sulphate and 100 g./litre of zinc sulphate. The term "polyalkylene glycol" is used in the Specification to include the ether and ester derivatives, including the hydroxy fatty acid esters.