Patent GB-537004-A (GB)
Title: Improvements in or relating to methods of treating cellulosic fibres or cellulosic textile material, and the products resulting therefrom
IPC: D06P1/673
Filed: 1939-08-22
Abstract: 537,004. Treating textiles with liquids ; refining cellulosic materials ; dyeing processes. STEVENS, A. H. (Ridbo Laboratories, Inc.). Aug. 22, 1939, No. 24174. [Classes 2 (ii) and 15 (ii)] Cellulose textile fibres or textile materials are treated for the removal therefrom of less polymerized celluloses, sugars, glucosides, and other impurities by treating them with a solution of a water-soluble copper salt, then treating them with a solution containing ammonium hydroxide and another alkaline hydroxide, the proportions and concentrations being such that no solution of the, α-cellulose content of the materials occurs. Copper sulphate solution may be used in such concentration that the amount of copper sulphate prior to the alkali treatment, in the case of light fabrics, does not exceed about one part of CuSO 4  .5H  2 O to four parts of cellulose. Lower strengths of the copper salt solution are used for heavy fabrics. The quantity of caustic soda or other alkaline hydroxide other than ammonia is preferably one part to 3 parts of copper sulphate salt. The treatment results in improved appearance, handle, stiffness, sheerness, hot flexing life, tensile strength, resistance to shrinking, resistance to wrinkling, resistance to mildew. There is imparted greater insulating power, greater moisture absorption power, and greater receptivity to dyeing treatments. The treatment may be applied locally, e.g., by printing with one or more of the reagents or by the use of resists. Such treatment results in pattern effects of contrasting shades on subsequent dyeing. Fibres, threads, cords, yarns, fabrics, or fibrous coverings may be treated. The process is applicable to natural or artificial fibrous material. The treated material is more readily coated or impregnated with varnishes, lacquers, crease-resisting and other agents, e.g., synthetic resins. Instead of copper sulphate there may be used the nitrate, bromide, or chloride. The excess salt solution may be removed by centrifuging or squeeze rolls. Prior to the treatment the materials may be boiled in water, rinsed, subjected to the action of a solution of " serizyme " or other enzyme for removal of starch, boiling with very dilute caustic soda and carbonate, acidifying, and washing. The process may be used for obtaining unshrinkable fabrics. After treatment with the copper solution and with the ammonium and sodium hydroxide solution the materials may be stretched 5-12 per cent. in both directions or 24 per cent. in one direction, treated with a more concentrated caustic soda solution, and washed to remove alkali. The tension is then relaxed and the copper compounds are removed by treatment with acid. For fabrics measuring 10 sq. yds. per pound, the proportion of copper sulphate salt to be left in the material prior to the alkali treatment is preferably not greater than 0.25 parts per. 1 part of cellulose; For fabrics measuring 1 sq. yd. per pound the proportion of copper salt is preferably not greater than 0.16, and the concentration is preferably not in excess of 285 grams CuSO 4 , 5H 2 O per litre. The ammonium hydroxide may be present to the extent of 8 mols. per 1 mol. of copper sulphate when working at 20‹ C.  Reference has been directed by the Comptroller to Specification 512,236 as open to inspection under Sect. 91.