Patent GB-398258-A (GB)
Title: Improvements in the production and treatment of artificial filaments, threads, yarns, ribbons and the like
IPC: D06M11/44
Filed: 1932-03-14
Abstract: Artificial filaments, threads, yarns, films, fabrics, &c., are delustred, weighted, mordanted, or the like by incorporating therein a wholly inorganic compound in finely divided form and treating the formed products with a reagent to convert it into its final form. Suitable inorganic compounds are the hydroxides of aluminium, zinc, and tin, barium carbonate, mono- and di-sodium phosphates, sodium silicate, sodium carbonate, sodium sulphate, sodium stannate, sodium zincate, barium chloride, and magnesium and zinc sulphates.  The yarn containing the inorganic compound is then treated with a reagent to convert the inorganic compound into its required form, e.g. yarn containing finely divided hydroxide of tin or zinc is treated with a solution of phosphoric acid or a phosphate.  The inorganic compound is preferably incorporated in the spinning solution e.g. by incorporating the finely divided compound with or without dispersing agents or protective colloids, or by dissolving it in a suitable liquid and adding to the spinning solution in which it is insoluble, so as to precipitate it in finely divided form.  An alternative procedure is to treat the formed filaments &c. for the introduction of the inorganic substance, preferably while the materials are in a swollen condition.  The reagent for converting the inorganic compound into its final form may also be applied to the materials whilst they are in a swollen condition.  The swelling agent may comprise the liquid medium from which the insoluble compound is applied, or by means of which it is converted into the final form. For example, cellulose acetate filaments may be treated with an alcoholic dispersion of zinc sulphate and subsequently passed through a solution of disodium phosphate, or materials containing finely divided sodium sulphate may be treated with an aqueous solution of barium thiocyanate which acts as the swelling agent. The insoluble inorganic compound may also be applied by padding or spraying, with or without the use of a stencil.  When it is desired to increase the heat resistance of the materials, the latter may be subjected to partial saponification, simultaneously with, or separately from the process of the invention.  The following examples are given:--(1) An acetone solution of cellulose acetate containing sodium sulphate in finely divided form is spun into an aqueous solution of barium thiocyanate and ammonium thiocyanate.  (2) An acetone solution of cellulose acetate containing precipitated tin hydroxide is spun, and the yarn immersed in hank form in a bath containing trisodium phosphate.  The yarn is partially saponified.  (3) Cellulose acetate yarn is soaked in a dispersion of sodium hydrogen phosphate in alcohol, lifted, and immersed without washing in a solution of sodium zincate.  The yarn is partially saponified. Specifications 246,879, 258,874, 260,312, 270,987, 272,982, 281,084, 285,941, 302,775, 306,611, 319,420, 336,621, 338,490, [all in Class 2 (ii), Cellulose &c.], 374,049, and 389,484 are referred to.