Patent GB-729643-A (GB)
Title: Process for improving the fastness of colouring matter in textile materials and paper sheets
Inventor: EVANS JOHN GWYNANT
IPC: D21H21/28
Filed: 1951-07-13
Abstract: The fastness of dye or pigment colourations on textile materials and paper sheets is improved by treating the material, in the absence of a filler, with an organic isocyanate or isothiocyanate or an adduct thereof with an organic compound, either together with or after the application of the colouring matter, and then heating to at least 100 DEG  C.  Treatment of textile materials containing natural or artificial amphoteric colloids with dyestuffs is excluded, as is also the use of aliphatic monofunctional isocyanates or isothiocyanates containing more than 7 carbon atoms in the aliphatic radicle.  Mono-, di- or tri-functional isocyanates and isothiocyanates may be employed, examples of which are ethyl isocyanate, phenyl isocyanate, hexamethylene di-isocyanate, toluylene 2 : 4-di-isocyanate, m-phenylene di-isocyanate, chlorophenylene 2 : 4-di-isocyanate, the mixture of polyisocyanates known as "Vulcafor" V.C.C. (Registered Trade Mark) and the corresponding isothiocyanates, allyl isothiocyanate, toluene-2 : 4 : 6-tri-isocyanate, mixtures of toluene-2 : 4- and 2 : 6-di-isocyanates and methylene bis-p-phenylene isocyanate.  Specified adducts are those of diethyl malonate, acetyl-acetone and acetoacetic ester with hexamethylene di-isocyanate.  The isocyanate or isothiocyanate may be applied in solution or dispersion or, when applicable, in vapour form, and also may be applied locally, as by printing or stencilling, or by the preapplication of resists or the subsequent application of a discharge paste prior to the heat treatment.  The heating step may be effected by hot air, infra-red radiation, molten metal or steam.  An amide, amidine or aminotriazine, e.g. urea, thiourea, acetamide, benzene sulphonamide, p-toluene sulphonamide, dicyandiamide, guanidine, aminoguanidine and melamine, may also be applied to the material to be present during the heat treatment.  Cationic dye-fixing agents, such as are described in Specifications 464,921 and 515,847, and anionic dye-fixing agents, such as phospho-tungsto molybdic acid, may be applied to the dyed material before or simultaneously with the application of the isocyanate.  The process improves the fastness of dyes and organic or inorganic pigments, e.g. acid, chrome, direct, basic, dispersed, vat and insoluble azoic dyes, "onium" dyes, as described in Specifications 613,980, 613,982, 613,983 and 619,035, iron oxide p  and hydrates, lead chromate, ferric ferrocyanide, cadmium sulphide, phthalocyanine pigments, and fluorescent coumarins and "Lumogens," and the dye or pigment may be applied in aqueous or organic-solvent dispersion or emulsion. Numerous examples are given of the process applied to fabrics of cellulose acetate, cotton, glass, nylon and "Terylene" (Registered Trade Mark), and in one case to a paper sheet.  The process may also be applied to natural, regenerated or modified protein textile materials. Specification 488,783 also is referred to.  According to the Provisional Specification, the pigment may be dispersed in aqueous solutions or dispersions of natural or synthetic polymeric substances, such as starches, gums, alginates, cellulose ethers, polyvinyl resins, alkyd resins and urea-formaldehyde, melamine-formaldehyde and phenol-formaldehyde resins.