摘要 |
<p>A composition for application to textiles with a subsequent heating step (see Group IV (c)) comprises an aqueous solution of a crystalloidal intermediate condensation product of a synthetic resin and an aqueous dispersion of a polysiloxane, which is an oily liquid and which on heating in thin layers gives an infusible, non-tacky, flexible film. Specified condensation products are those of urea-formaldehyde, melamine-formaldehyde or ethers thereof, alone or in admixture, and phenol-formaldehyde. Hardening catalysts, e.g. acids such as tartaric or ammonium salts thereof, aluminium chloride or zinc nitrate for the precondensate, and zinc naphthenate or calcium, zinc or cobalt-stearate for the polysiloxane, may be incorporated in the solutions or dispersions. To the impregnating liquors may also be added inert fillers, colloidal dispersions of, e.g. urea-formaldehyde resins, natural or synthetic rubber, delustring agents and pigments. Numerous examples are given in which methyl hydrogen siloxane is emulsified in a small amount of xylene and then mixed with the aqueous solution of the precondensate, the siloxane-xylene emulsion containing minor amounts of glacial acetic acid, calcium stearate an ethylene oxide condensate, trimethylbenzyl ammonium chloride and sodium oleyl sulphate. A suitable urea-formaldehyde crystalloidal condensation production may be prepared according to Specification 449,243.ALSO:Cellulosic textile materials, e.g. fibres, yarns and fabrics, are given a resistance to creasing, water, mildew and soiling, a soft hand, an increased strength and, when dyed or printed, an increased fastness to light and washing, by impregnating them, in either order or simultaneously, and, if desired, by local application, with an aqueous solution of a crystalloidal intermediate condensation product of a synthetic resin and with an aqueous dispersion of a polysiloxane, which is an oily liquid and which on heating in thin layers gives an infusible, non-tacky, flexible film. The impregnated materials are then heated to render the resin insoluble and the silicon compound infusible. Specified condensation products are those of urea-formaldehyde, melamine-formaldehyde or ethers thereof, alone or in admixture, and phenol-formaldehyde. Heating is effected at 100-200 DEG C., if desired in the presence of steam. Hardening catalysts, e.g. acids such as tartaric or ammonium salts thereof, aluminium chloride or zinc nitrate for the precondensate, and zinc naphthenate or calcium, zinc or cobalt stearate for the polysiloxane, may be incorporated in the solutions or dispersions. Prior to impregnation, the materials are preferably rendered absorbent by treatment with alkaline solutions. After drying, but before or simultaneously with the heating step, impregnated fabrics may be given a mechanical finishing effect, as by calendering, embossing, schreinering, glazing or controlled shrinking. To the impregnating liquor may also be added inert fillers, colloidal dispersions of, e.g., urea-formaldehyde resins, natural or synthetic rubber, delustring agents and pigments. Numerous examples are given in which methyl hydrogen siloxane is emulsified in a small amount of xylene and then mixed with the aqueous solution of the precondensate, the siloxane - xylene emulsion containing minor amounts of glacial acetic acid, calcium stearate, an ethylene oxide condensate, trimethylbenzyl ammonium chloride and sodium oleyl sulphate. Cotton or regenerated cellulose fabrics are padded with the mixture and then dried and baked. A suitable crystalloidal urea-formaldehyde condensation production may be prepared according to Specification 449,243. According to the Provisional Specification the process may be applied to all fibrous materials</p> |