Patent GB-517886-A (GB)
Title: Improvements in the production of artificial threads, filaments and formations of cellulose ethers and esters, and of regenerated cellulose
IPC: C08L1/00
Filed: 1938-08-15
Abstract: 517,886. Artificial filaments etc.; treating textiles with liquids. LEWIS,F. D. Aug. 15, 1938, No. 23960. [Classes 2 (ii) and 15 (ii)] Sulpho-salts of barium or lead which are relatively stable in aqueous solution or suspension at the ordinary temperature but which are converted into barium or lead sulphate by heat in presence of water, or components of such salts are used as potential delustrants for filaments, threads, or other articles of regenerated cellulose or cellulose esters or ethers. They are incorporated in the formed products or in a solution of a cellulose ester or ether in a volatile solvent. Dulling is effected by application of heat to the products' in the presence of water. Barium or lead derivatives of alkyl or terpenyl hydrogen sulphates or pyrosulphates or of persulphuric acid may be used. Components of these salts include persulphates or alkyl or terpenyl sulphates or pyrosulphates of alkali metals or of ammonium and oleates or watersoluble salts of barium or lead. Since the salts are converted to the opaque sulphates by heat, the extent of delustring may be controlled and local or differential effects may be obtained. The potential delustrant may be the solid barium, or lead compound of ethyl hydrogen sulphate or a similar compound in which the alkyl constituent is derived from methanol, butanol, or alcohols from pine oil, cotton or flax wax, or wool grease. It may be an aqueous, alcoholic, or ketonic solution of a barium or lead alkyl sulphate or pyrosulphate. The potential delustrant may be mixed with potassium oleate, barium .or lead oleate, or other antiacid compound in order to prevent deterioration of cellulose esters by premature hydrolysis of the potential delustrant. The threads containing the potential delustrant and anti-acid body may be damped with water and then dulled by contact with a heated metallic surface or stencil, or they may be damped with a solution of a barium or lead salt. When the delustrant is added to a cellulose ester solution in a volatile solvent . and threads are obtained by dry spinning the temperature of the evaporative medium may be such as to produce deposition of the insoluble sulphate in the threads during their production. The spinning solution may contain a halogenated hydrocarbon, e.g., carbon tetrachloride, methylene bromochloride, ethylene dichloride, or methyl iodide, in conjunction with acetone or other solvent, whereby filaments of round polylobate cross-section are obtained. A solution of a cellulose ether and an ammonium alkyl sulphate in acetone may be dry spun and the product may be damped with barium hydroxide solution. A regenerated cellulose textile may be damped with an aqueous solution of barium hydroxide and an ammonium alkyl sulphate. The potential delustrant may be used with a vehicle such as a cellulose xanthylarylamine, or an aryl ether, di-p-chlorm-cresyl ether, di-p-chlor-m-xylyl-ether, or di-p-chlorbenzyl ethyl ether of glycerol or glycol. The delustrants may be used in conjunction with other dulling agents, e.g., polychlornaphthalenes, and p-chlor-m-xylyl polychlorbenzyl ethers. Specifications 231,801, [Class 2 (ii)], and 413,087 are referred to.