ES265582A1 - Manufacture of viscose rayon - Google Patents

Abstract

A viscose spinning solution includes an alkali lignosulphonate and a quaternary derivative of an alkoxylated amine. The alkali lignosulphonate is preferably sodium lignosulphonate having 0,5-4,0 moles of sulphonation per mole of lignin, and present to the extent of 0,5-3,0% by weight, especially 2,5% based on the weight of the cellulose in the viscose. The quaternary derivative of an alkoxylated amine is preferably a compound of the general formula <FORM:0937253/IV(a)/1> where R is an alkyl, aryl or alicyclic radical having at least six carbon atoms, R1 is an alkyl radical having 1-3 carbon atoms, x plus y is from 2-50, x and y being whole numbers, n is a whole number from 1-3, and Z is a surface inactive anion, e.g. hydroxide, halide, sulphate or acetate, present to the extent of 0,5-4,0% by weight, based on the weight of the cellulose in the viscose. Desirably the quaternary derivative is a compound of the same general formula where R is an aliphatic radical derived from coconut oil, from coconut fatty acids, from soya fatty acids, from tallow, or from n-octadecylamine, and x + y = 2, 10, 15 or 50. A suitable viscose contains 4-8% cellulose, 4-8% total alkali expressed as NaOH, and 1,2-3,5% total sulphur, having an ammonium chloride number of 10-21 and a spinning viscosity of 30-100 seconds. A suitable coagulating bath contains 2,5-7,0% by weight sulphuric acid, 5,0-20,0% anhydrous sodium sulphate, and 3,0-15,0% anhydrous zinc sulphate. Magnesium sulphate and formaldehyde may also be present and the bath temperature may range from about 30 DEG -70 DEG C., 50 DEG C. being preferred. Spinning speeds should not exceed 90 m./min., 35-65 m./min. being preferred. The filaments formed may be stretched from 20-150%, preferably from 100-110% while passing through a second hot bath containing 4% by weight sulphuric acid, 0,3% anhydrous sodium sulphate, and 1,2% anhydrous zinc sulphate, maintained at 50 DEG -100 DEG C., preferably 85 DEG -100 DEG C. An intermediate formaldehyde may be added to the coagulating bath, or used in a second bath. Filaments so made are of high tenacity and suitable for making tyre cord. Specifications 784,896, 871,334 and U.S.A. Specification 2,852,334 are referred to.