Patent GB-741728-A (GB)
Title: Manufacture of regenerated cellulose structures from viscose
IPC: D01F2/10
Filed: 1952-05-12
Abstract: In the production of regenerated cellulose filaments and other products from viscose, a compound of the formula RO-(CH2CH2O)n-R1 is added to the viscose, preferably in a proportion of 0.5 to 1.0 per cent, and the mixture is extruded into an acid coagulating bath which preferably contains up to 15 per cent of zinc sulphate.  The compound should be at least one per cent soluble in 6 per cent aqueous sodium hydroxide solution and not more than 0.5 per cent soluble at room temperature in the particular coagulating bath employed.  In the formula, R is an alkyl or aryl radical, n is 1-4 (preferably 1 or 2) and R1 is hydrogen or an alkyl or aryl radical.  Preferably the coagulated filaments are treated in a secondary hot bath (which may be water or 1-3 per cent sulphuric acid at 50-100 DEG  C.) and stretched before they are wound.  The viscose used may contain 4-10 (preferably 5-7) per cent of cellulose and 4-9 (preferably 4-7) per cent of alkali, and may have a relatively high salt index.  The viscose may be unripened; and the bath temperature is preferably 40-75 DEG  C. Specified additives of the formula above include ethoxy-, butoxy-, phenoxy-, methoxyethoxy-, butoxyethoxy- and phenoxyethoxy ethanols, diethylglycol ether and 1-ethenyloxy-2-methoxyethylene.  In an example an unripened viscose, in which 0.5 per cent of phenoxyethanol has been mixed for 3 hours at 17 DEG  C. is spun into a primary aqueous coagulating bath containing 6.5 per cent of sulphuric acid, 17.8 per cent of sodium sulphate and 9.5 per cent of zinc sulphate at 60 DEG  C., and the filaments are passed through a 2 per cent sulphuric acid bath at 98 DEG  C., stretched 100 per cent and collected on a bobbin.  In other examples viscoses containing some of the additives listed above are spun in a similar manner and, in addition, examples are given of the spinning of unripened viscoses containing compounds of the formul C2H5O-(C2H4O)3-H; C4H9O-(C2H4O)3-H; and C6H5O-(C2H4O)3-H. Polyethylene glycols, preferably of mol. wt. 300-1000, the amines referred to in Specification 654,083 and the diamines referred to in Specification 741,727 may be used in conjunction with the compounds of the formula given above.  In an example a viscose modified with 0.5 per cent of butoxyethanol, 0.2 per cent of polyethylene glycol (M.W. = 300) and 0.1 per cent of cyclohexylamine is spun as in the first example.  The filaments have low gel-swelling values, high tenacities, substantially noncrenulated surfaces and a high proportion of skin.  For the purpose of comparison, particulars are given of certain physical properties of filaments spun from viscose containing ethoxyethylacetate, the di(chlorethyl) ether of ethylene glycol, glycol diacetate, glycol diformate, the mono(chlorethyl) ether of ethylene glycol, ethoxyethyl acrylate, butoxyethoxyethyl acetate, the acetate of the monomethyl ether of triethylene glycol and triethylene glycol dicaprylate.  Specifications 652,741 and 685,843 and U.S.A. Specifications 2,040,712, 2,440,057, 2,511,699 and 2,536,014 also are referred to.