Patent GB-716233-A (GB)
Title: Improvements in the treatment of cellulosic textile materials, films, paper and pulp
Inventor: EVANS JOHN GWYNANT
IPC: D06M13/256
Filed: 1950-03-10
Abstract: Fibres, yarns and fabrics composed of or containing natural cellulose, regenerated cellulose or cellulose esters or ethers, or films and foils of regenerated cellulose or cellulose esters or ethers, or paper and pulp are given modified dyeing properties, a reduced water inhibition, a reduced swelling in water, an increased wet strength and an increased resistance to shrinkage by applying thereto a reaction product of an organic mono- or poly-functional isocyanate or isothiocyanate and an alkali metal bisulphite and then heating to a temperature at least as high as the decomposition temperature of the reaction product, e.g. to 100-200 DEG C.  The reaction product may be applied in aqueous solution or dispersion or, alternatively, the reaction product may be formed in situ on the material by either applying, in any order, an aqueous solution of the bisulphite and an organic solvent solution of the isocyanate or isothiocyanate, or by applying an emulsion of the isocyanate in an aqueous bisulphite solution.  The impregnated material may be partially dried prior to the heating step, or alternatively, the drying and heating operations may be effected simultaneously. Heating may be effected with hot air, infra-red radiation, molten metal or steam. Local or pattern effects may be obtained by printing the reaction product on the material, or alternatively, by the pre-application of resists or the subsequent application of a discharge paste prior to the heat treatment.  The treated materials have a high or improved affinity for acid, chrome, basic, direct and dispersed insoluble dyes which may be applied to the materials simultaneously with the reaction product.  When dyes sensitive to reduction by the reaction product are applied, anti-reducing agents, e.g. sodium-m-nitro-benzene sulphonate, are incorporated. The wet strength of paper and films of regenerated cellulose and cellulose esters and ethers is considerably increased if an amide, e.g. urea, thiourea, acetamide, benzene sulphonamide, p-toluene sulphonamide or dicyandiamide, is present on the material during the heat treatment. Softening and lubricating agents, antiseptics and anti-crease agents, e.g. thermo-setting resinous condensates, may be applied to fabrics before, after or simultaneously with the reaction product.  Reaction products of bisulphites with both aliphatic and aromatic isocyanates and isothiocyanates, e.g. phenyl isocyanate, hexamethylene di-isocyanate, m-toluylene di-isocyanate, m-phenylene di-isocyanate and the corresponding isothiocyanates, allyl isothiocyanate, toluene-2:4-di-isocyanate, toluene - 2:4:6 - tri-isocyanate, mixtures of toluene 2:4-and:2:6-di-isocyanates, methylene bis-p-phenylene isocyanate and the mixture of poly-isocyanates known under the Registered Trade Mark "Vulcafor V.C.C.," may be employed.  Numerous examples are given of the treatment of cotton and viscose rayon fabrics and paper, and in some cases the fabrics are simultaneously or subsequently dyed. Specifications 317,019, [Class 15 (ii)], and 716,232 are referred to.ALSO:Bisulphite-organic isocyanate and bisulphite-organic isothiocyanate reaction products, suitable for use in the treatment of textiles, films and paper (see Groups IV (a), IV (c) and VIII), are prepared by dispersing the liquid isocyanate or isothiocyanate or a solution of the solid isocyanate or isothiocyanate in an organic solvent such as benzene, toluene or xylene, into a saturated aqueous solution of the bisulphite, e.g. sodium or potassium bisulphite, from which the reaction product separates out.  Reaction products of sodium or potassium bisulphites with phenyl isocyanate, hexamethylene di-isocyanate, m-toluylene di-isocyanate, m-phenylene di-isocyanate and the corresponding isothiocyanates, allyl isothiocyanate, toluene 2 : 4-di-isocyanate, toluene 2 : 4 : 6-tri-isocyanate, mixtures of toluene 2 : 4- and 2 : 6-di-isocyanates, methylene bis-p-phenylene isocyanate and the mixture of polyisocyanates known under the Registered Trade Mark "Vulcafor" V.C.C. are specified.  In example XIV, after first preparing the sodium bisulphite reaction product of hexamethylene diisocyanate, it is dissolved in water, the solution heated to 60 DEG C., with the addition of potassium chloride and on cooling to 5 DEG C. the more sparingly soluble potassium bisulphite reaction product crystallizes out.ALSO:Fibres, yarns and fabrics composed of or containing natural cellulose, regenerated cellulose or cellulose esters or ethers, or films and foils of regenerated cellulose or cellulose esters or ethers, or paper and pulp are given modified dyeing properties, a reduced water imbibition, a reduced swelling in water, an increased wet strength and an increased resistance to shrinkage by applying thereto a reaction product of an organic mono- or polyfunctional isocyanate or isothiocyanate and an alkali metal bisulphite, and then heating to a temperature at least as high as the decomposition temperature of the reaction product, e.g., to 100 DEG -200 DEG C.  The reaction product may be applied in aqueous solution or dispersion or, alternatively, the reaction product may be formed in situ on the material by either applying, in any order, an aqueous solution of the bisulphite and an organic solvent solution of the isocyanate or isothiocyanate, or by applying an emulsion of the isocyanate in an aqueous bisulphite solution.  The impregnated material may be partially dried prior to the heating step, or alternatively, the drying and heating operations may be effected simultaneously.  Heating may be effected with hot air, infra-red radiation, molten metal or steam. Local or pattern effects may be obtained by printing the reaction product on the material, or alternatively, by the pre-application of resists or the subsequent application of a discharge paste prior to the heat treatment.  The treated materials have a high or imposed affinity for acid, chrome, basic, direct and dispersed insoluble dyes which may be applied to the materials simultaneously with the reaction product, this latter mixture constituting a marketable composition.  When dyes sensitive to reduction by the reaction product are applied, anti-reducing agents, e.g., sodium-m-nitrobenzene sulphonate, are incorporated. The wet strength of paper and films of regenerated cellulose and cellulose esters and ethers is considerably increased if an amide, e.g., urea, thiourea, acetamide, benzene sulphonamide, p-toluene sulphonamide or dicyandiamide, is present on the material during the heat treatment.  Softening and lubricating agents, antiseptics and anti-crease agents, e.g., thermosetting resinous condensates, may be applied to fabrics before, after or simultaneously with the reaction product. Reaction products of bisulphites with both aliphatic and aromatic isocyanates and isothiocyanates, e.g., phenyl isocyanate, hexamethylene di-isocyanate, m-toluylene di-isocyanate, m-phenylene di-isocyanate and the corresponding isothiocyanates, allyl isothiocyanate, toluene 2:4 di-isocyanate, toluene 2:4:6 tri-isocyanate, mixtures of toluene 2:4 and 2:6 di-isocyanates, methylene bis-p-phenylene isocyanate and the mixture of polyisocyanates known under the Registered Trade Mark "Vulcafor" V.C.C. may be employed.  Numerous Examples are given of the treatment of cotton and viscose rayon fabrics and paper, and in some cases the fabrics are simultaneously or subsequently dyed.  Specifications 317,019.  [Class 15(ii)], and 716,232 are referred to.