Patent GB-758937-A (GB)
Title: Method for rendering polyacrylonitrile filaments and other articles readily dyeable
IPC: D06P3/70
Filed: 1953-11-10
Abstract: Filaments, films, rods, tubes, and similar articles of acrylonitrile polymers containing at least 85 per cent of acrylonitrile in the polymer molecule are obtained with good dyeing affinities by spinning an aqueous saline solution of the polymer into an aqueous coagulant, stretching the formed articles, freeing them from salts, and incorporating in them while they are in the aquagel condition at any stage before drying, at least 1 per cent of their dry weight of a dye assistant which is soluble in water and is either an amine salt, a quaternary ammonium salt, a sulphonium salt, a phosphonium halide, or a polymer of a N-vinyl derivative of a carboxylic acid amide or lactam.  The dye assistant may be introduced into the coagulated and still swollen spun product before or after partial orientation.  The products may be dyed with various kinds of dyes, e.g. with dyes commonly used for dyeing wool, cotton, silk, viscose or acetate rayon, or nylon.  Numerous examples of suitable dye assistants are specified, including as water-soluble amine salts: octadecyl ammonium chloride, N - 2 - [2 - (2,2,3,3 - tetramethylbutyl phenoxy) - ethoxy]ethyl - N,N - dimethyl ammonium chloride, 2-n-nonyl pyridine hydrochloride, and 2-heptadecyl-3-butyl glyoxalidine hydrochloride; as quaternary ammonium salts: n-dodecylbenzyl trimethyl ammonium chloride, 2 - hydroxyethyl - n - octadecyl - dimethyl ammonium bromide, benzyl-2-[2-(2,3,4,6-tetrachlorophenoxy) - ethoxy] ethyl morpholinium chloride, n-hexadecyl pyridinium chloride, n-dodecyl isoquinolinium bromide, bis-(polyoxyethylene oleate)-ethyl methyl ammonium ethosulphate, pentamethylene bis-(n-dodecyl dimethyl ammonium chloride), and dimethyl 2-hydroxyethyl stearamidopropyl ammonium chloride; as water-soluble sulphonium salts: n-dodecyl dimethyl sulphonium chloride, bromide, or methosulphate, di-(2-hydroxyethyl)-methyl sulphonium methosulphate di-capric ester, and n-dodecyl 2-chloroethyl methyl sulphonium 2-chloroethyl sulphate; as phosphonium halides: cetyl trimethyl phosphonium chloride, benzyl n-dodecyl dimethyl phosphonium bromide, benzyl cetyl dimethyl phosphonium iodide, and dichlorobenzyl triphenyl phosphonium chloride; and as water-soluble polymers of N-vinyl derivatives of carboxylic acid amides or lactams: N-vinyl a -pyrrolidone, N-vinyl N-methyl (or ethyl) formamide (or acetamide), and N-vinyl capro (or valero) lactam.  The undried fibres or other articlse may be soaked in a solution of the dye assistant at a pH of 1-8 at temperatures below 10 DEG  C. up to 100 DEG  C.  The treated and subsequently dried materials may be dyed with direct cotton dyes, azoic dyes, vat dyes, soluble vat dyes; acid, acid-mordant, and basic dyes; and acetate dyes.  In an example, a water-swollen unstretched tow, formed by extrusion of a saline solution of polyacrylonitrile into an aqueous coagulating bath, is soaked in a solution of dodecyl trimethyl ammonium chloride and then stretched and dried.  The tow is dyed in a hot bath containing Pontamine Green and sodium sulphate. In another example, the tow is impregnated with the dye assistant after the stretching and before drying.  It is then dyed in a bath containing Sulphanthrene Red, caustic soda, and sodium hydrosulphite, the dye being developed by treatment of the impregnated tow with a solution of hydrogen peroxide.ALSO:For improving the dyeing affinities of filaments, films, rods, tubes, and similar articles of acrylonitrile polymers containing at least 85 per cent of acrylonitrile in the polymer into an aqueous coagulant and spinning an aqueous saline solution of the polymer into an aqueous coagulate and which are stretched, washed, and subsequently dried, there is applied to the articles while they are in an aquagel condition at any stage before drying, at least 1 per cent of their dry weight of a dye assistant which is soluble in water and is either an amine salt, a quaternary ammonium salt, a sulphonium salt, a phosphonium halide, or a polymer of a N-vinyl derivative of a carboxylic acid amide or lactam.  The articles may be dyed with various kinds of dyes, e.g. with dyes commonly used for dyeing cotton, wool, silk, viscose or acetate rayon, or nylon.  Numerous examples of suitable dye assistants are specified, including as amine salts:-octadecyl ammonium chloride, N-2-[2-(2, 2, 3, 3, -tetramethyl butyl phenoxy)-ethoxy] ethyl-N, N-dimethyl ammonium chloride, and 2-n-nonyl pyridine hydrochloride; as quaternary ammonium salts:-n-dodecylbenzyl trimethyl ammonium chloride, benzyl -2- [2-(2, 3, 4, 6-tetrachlorophenoxy)ethoxy] ethyl morpholinium chloride, and n hexadecyl pyridinium chloride; as sulphonium salts:-n-dodecyl dimethyl sulphonium chloride, bromide, or methosulphate, and di-(2-hydroxyethyl) methyl sulphonium methosulphate dicapric ester; as phosphonium halides: -cetyl trimethyl phosphonium chloride, benzyl cetyl dimethyl phosphonium iodide, and dichlorobenzyl triphenyl phosphonium chloride; and as polymers of N-vinyl derivatives of carboxylic amides or lactams:-N-vinyl-a -pyrrolidone, N-vinyl-N-methyl (or ethyl) formamide (or acetamide), and N-vinyl capro (or valero) lactam. The aquagel fibres or other articles may be soaked in a solution of the dye assistant at a pH of 1-8 at below 10 DEG C up to 100 DEG C. The treated and subsequently dried materials may be dyed with direct cotton dyes, azoic, vat, soluble vat, acid, mordantacid, basic, and acetic dyes.  When dyeing with a soluble vat dye, e.g. Indigosol Green, the dye bath may be prepared by dissolving the dyestuff in hot water containing sodium carbonate and then adding sodium hydrosulphite and sodium sulphate.  The goods may be entered at 40 DEG C. and the temperature gradually raised to 90 DEG C. The goods are subsequently placed in a developing bath containing ammonium thiocyanate and potassium dichromate at 30 DEG C.  Dilute sulphuric acid is added and the temperature raised to 85 DEG C.  The goods are then washed and neutralized.  In an example, a tow of polyacrylonitrile after leaving the coagulating bath is soaked with a solution of dodecyl trimethyl ammonium chloride and then stretched, dried, and subsequently dyed in a hot bath containing Pontamine Green and sodium sulphate.  A similar tow is stretched before the impregnation with the dye assistant, and after drying is dyed in a bath containing Sulphanthrene Red, caustic soda, and sodium hydrosulphite and the dye is developed by treatment with hydrogen peroxide.  A similar tow is impregnated with polyvinyl pyrrolidone, padded with Naphtholate A.S. and then entered into a bath containing diazotized 2-chloro-4-nitraniline at 95-100 DEG C. The tow is passed into a developing bath containing formic acid, acetic acid, and sodium sulphate.