Patent GB-600355-A (GB)
Title: Improvements in and relating to treating textile materials
IPC: D06M15/09
Filed: 1944-09-26
Abstract: Textile materials are impregnated or coated with a solution of a cellulose alkyl ether in an aqueous solution of an alkali-metal zincate containing excess of alkali-metal hydroxide; the cellulose ether is then precipitated on to the material, and part but not all of the zinc is removed by a washing treatment.  Pigments may be incorporated in the solution.  Since the zincate solution has a solvent action on the surface of the fibres of the textile material, the cellulose ether coating becomes firmly united to the fibres upon precipitation.  In making the solution, the cellulose ether may be wetted with part of the water, e.g. by slurrying with about 5 to 10 times its weight of water.  A concentrated solution of alkali metal zincate is then added and after stirring, the remainder of the water is added to produce a solution of the desired concentration.  The final amount of water may be added in the form of cracked ice.  The solvent medium may comprise 8-15 parts of sodium hydroxide, 2 parts up to the saturation proportion of zinc oxide, and 100 parts of water.  The cellulose ether may comprise 1-8 per cent of the solution.  Preferably, an alkali soluble, water-insoluble cellulose ether is used, e.g. a low substituted methyl, ethyl, hydroxyethyl, or carboxymethyl cellulose ether.  Precipitation of the cellulose ether may be effected by acidification, by addition of an electrolyte to the solution, or by diluting with a large quantity of water, alcohol, or other non-solvent.  The zinc compound left in the fibres decreases the lustre of rayon fabrics and improves the fastness to dyes. Fabrics are stiffened by the treatment.  In an example, a fabric of cotton, regenerated cellulose, cellulose acetate, or a mixture of one of these materials with silk, or wool, is padded with a cellulose ether solution in sodium zincate and sodium hydroxide solution.  The fabric with adhering film of the solution is passed through dilute sulphuric acid to precipitate the cellulose ether.ALSO:Textile materials are impregnated or coated with a solution of a cellulose alkyl ether in an aqueous solution of an alkali-metal zincate containing excess of alkali-metal hydroxide; the cellulose ether is then precipitated on to the material, and part but not all of the zinc is removed by a washing treatment.  Pigments may be incorporated in the solution.  Since the zincate solution has a solvent action on the surface of the fibres of the textile material, the cellulose ether coating becomes firmly united to the fibres upon precipitation. In making the solution, the cellulose ether may be wetted with part of the water, e.g. by slurrying with about 5 to 10 times its weight of water.  A concentrated solution of alkali metal zincate is then added and after stirring, the remainder of the water is added to produce a solution of the desired concentration.  The final amount of water may be added in the form of cracked ice.  The solvent medium may comprise 8-15 parts of sodium hydroxide, 2 parts up to the saturation proportion of zinc oxide, and 100 parts of water.  The cellulose ether may comprise 1-8 per cent of the solution. Preferably, an alkali-soluble, water-insoluble cellulose ether is used, e.g. a low substituted methyl, ethyl, hydroxyethyl, or carboxymethyl cellulose ether.  Precipitation of the cellulose ether may be effected by acidification, by addition of an electrolyte to the solution, or by diluting with a large quantity of water, alcohol or other non-solvent.  The zinc compound left in the fibres decreases the lustre of rayon fabrics and improves the fastness to dyes. Fabrics are stiffened by the treatment.  In an example, a fabric of cotton, regenerated cellulose, cellulose acetate or a mixture of one of these materials with silk, or wool, is padded with a cellulose ether solution in sodium zincate and sodium hydroxide solution.  The fabric with adhering film of the solution is passed through dilute sulphuric acid to precipitate the cellulose ether.  Yarns or threads may be treated similarly. After passage through the acid, the fabric is incompletely washed so as to leave some of the zinc compound in the material. Residual acid may be neutralized by means of sodium carbonate solution which also causes zinc carbonate to be precipitated on the material.  A cotton fabric may be padded with a cellulose ether-zincate solution and then passed through caustic soda of mercerizing strength and subjected to the usual mercerizing treatment.  The cellulose ether is precipitated by the strong alkali.