Patent GB-716234-A (GB)
Title: Retention of fillers in textile materials
Inventor: EVANS JOHN GWYNANT
IPC: D06M15/564
Filed: 1950-03-21
Abstract: In example IV the potassium bisulphite reaction product of phenyl isocyanate is prepared by stirring a mixture of phenyl isocyanate and aqueous sodium bisulphite at 5 DEG  C., adding water at 35 DEG  C., filtering warm, cooling to 5 DEG  C. when diphenyl urea is precipitated and filtered off, and adding potassium chloride to the solution when the potassium bisulphite reaction product is precipitated.ALSO:The retention of hydrophilic, non-fibrous, polymeric organic fillers in fibrous textile materials is improved by applying to the fibrous material a reaction product of an alkali metal bisulphite and an organic isocyanate or isothiocyanate, before, during or after the application of the filler, the materials containing the filler and the reaction product then being heated, e.g., to 100 DEG -200 DEG C. for 1-15 minutes.  The filler and the reaction product are preferably applied in the same or different aqueous solution or dispersion.  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, and to any of these liquids the filler may be added.  Specified fillers are starches, gums, alginates, cellulose ethers, proteins such as albumen, casein and zein, polyvinyl alcohol, partially hydrolysed polyvinyl acetate and polyacrylic acid and its soluble salts.  Loading and delustring agents, e.g., china clay, lithopone, barytes and titanium dioxide may be applied with the filler.  The heating operation, which may be combined with a pre-drying step, may be effected with hot air, infra-red radiation, molten metal or steam.  Enhanced effects are obtained if the heating step is effected in the presence of an amide, amidine or aminotriazine, e.g., urea, thiourea, acetamide, benzene sulphonamide p-toluene sulphonamide, dicyandiamide, guanidine, amino guanidine and malamine.  The treated materials may be subsequently dyed and the filler may act as a mordant for a dye which will normally not dye the materials or which is easily removed therefrom. The treated materials, prior to or simultaneously with the heating step, may have mechanical finishers applied thereto, as described in Specification 716,232, the finishes including mechanically enforced shrinking or stretching by the machines of Specifications 359,759 and 372,803, [both in Group VIII].  Local or pattern effects may be obtained by printing the reaction product on the material, or alternatively by the pre-application of resists or by the subsequent application of a discharge paste prior to the heat treatment. Softening, lubricating and anti-crease agents and antiseptics may be applied to the materials before, after or simultaneously with the reaction product.  Reaction products of bisulphites with both aliphatic and aromatic isocyanates and isothiocyanates may be employed, the specified reaction products being those specified in Specification 716,233.  The treatment is especially applicable to textile materials of natural or regenerated cellulose, cellulose esters or ethers, wool and natural silk, particularly fabrics or yarns. Numerous examples are given.