GB732126A - A process for rendering textile and sheet materials hydrophobic - Google Patents

Abstract

732,126. Waterproofing textile materials. FARBENFABRIKEN BAYER AKT.-GES. June 27, 1952 [June 28, 1951], No. 16310/52. Class 140. Textile and sheet materials which have been treated with at least one wax and/or liquid or solid paraffin hydrocarbon together with an agent consisting of or containing an aliphatic isocyanate having a carbon chain of at least 10 carbon atoms as such or mixed with an amine or polyamine, or a mixture of a polyisocyanate having a carbon chain of less than 10 carbon atoms with an amine or polyamine having a carbon chain of at least 10 carbon atoms are rendered hydrophobic by treating with an aqueous solution of a compound of aluminium or zirconium having a pH from 3 to 5.5 and then heating the resulting material. Suitable aluminium compounds include aluminium formate, aluminium acetate and aluminium sols. Suitable zirconium compounds include zirconium formate, zirconium acetate, zirconium soaps or zirconium sols, zirconium lactic acid or its alkali salts and similar complex salts, zirconium oxynitrate and zirconium oxychloride, the last mentioned salts being preferably buffered by means of sodium acetate and acetic acid or the like in order to obviate destruction of the fibres. Suitable waxes and liquid or solid paraffin hydrocarbons are montan wax, ketones of fatty acids having a carbon chain of at least 10 carbon atoms, polyethylenes, hard solid paraffin hydrocarbons and the liquid or solid paraffin hydrocarbons obtainable by the process of synthesizing gasoline according to the Fischer-Tropsch process. These agents are preferably applied in the form of their water-soluble derivatives, such as the addition products of bisulphite and the isocyanates and their reaction products with formaldehyde as well as the reaction products of the amines with formaldehyde and bisulphites. The materials to be treated may be soaked with aqueous emulsions of waxes and/or liquid or solid paraffin hydrocarbons and with aqueous solutions of the above defined agents squeezing the materials and drying them at elevated temperature. If water-soluble amines having a carbon chain of at least 10 carbon atoms form part of the agents mentioned, they may simultaneously serve as emulsifying agents for preparing the wax and/or liquid or solid paraffin hydrocarbon emulsion. The action of the compounds of polyvalent metals may take place at any time after the materials have been treated with the agents preferably by soaking with aqueous solutions of the metal compounds and after squeezing drying at elevated temperature of about 100‹ C. Pre-treatment with suitable wetting agents such as soaps, alkyl-aryl sulphonates and subsequent rinsing with water may be employed if the materials are not sufficiently wetted. In an example a raincoat material of cotton poplin is soaked with an emulsion formed by introducing while stirring 100 c.c. of an emulsion containing per litre 25 grams of a paste of 24 per cent of a solid paraffin hydrocarbon melting at about 50‹ C., 4.25 per cent of ceresine, 7.75 per cent of montanic acid ester, 5.2 per cent of sodium oleate and 2.5 per cent of the sodium salt of oleylmethylaminoethane sulphonic acid into the solution formed by adding to a solution of 25 grams of the addition product of sodium bisulphite and stearyl isocyanate in half-litre of water at 85 ‹ C. with which 7.5 c.c. of 33 per cent formaldehyde have been mixed, 3 c.c. of a 10 per cent sodium carbonate solution and after two minutes 2 c.c. of formic acid, the whole emulsion being made up to one litre by adding water at 40‹ C., the material is then squeezed so that the increase in weight is 65 per cent, dried at 100‹ C. and heated to 120‹ C. for 5 minutes. The material is then wetted by dipping in a 0.1 per cent sodium carbonate solution at 45 ‹ C. for one hour or into a 0.1 per cent sodium carbonate solution at 80‹ C. for ten minutes or into a 0.2 per cent solution of sodium salt of sobutiyl naphthalene sulphonic acid at 45‹ C. for five minutes or into a solution at 45 ‹ C. containing per litre 1 gram of soap and 1 gram of sodium carbonate for five minutes. After rinsing the material and squeezing it is treated with a 0.5 per cent solution of zirconium acetate for one minute after which the material is again aqueezed and dried at 100‹ C.