| 摘要 |
<p>900,382. Agglutinated fibrous materials. FREUDENBERG, R., FABBICIUS, H., FREUDENBERG, H. E., KRAFT, K., SCHILDAUER, O., WENTZLER, P., FREUDENBERG, H., and FREUDENBERG, D. April 28, 1961 [April 28, 1960], No. 15503/61. Class 140. A process for producing a non-woven fabric comprises impregnating a loose fibre fleece with a water-soluble binding agent which contains hydroxyl and carboxyl groups and then causing at least some of the hydroxyl groups to react with a water-soluble synthetic resin pre-condensate and causing the carboxyl groups to form a water-insoluble salt upon reaction with a metal salt, whereby the binding agents is rendered insoluble. Suitable binding agents are alkali metal and ammonium salts of alginic acids, carboxymethylcelluloses and carboxyethylcelluloses. Suitable synthetic resin pre-condensates are tetramethylolacetylenediurea, dimethyloldihydroxyethyleneurea and dimethylolethyleneurea. A suitable metal salt is aluminium formate. Impregnation may be effected by forming a solution of the binding agent into a foam and impregnating the fleece therewith, or by passing the fleece, sandwiched between two wire screens through a bath containing an aqueous solution of the binding agent. The fleece is then treated with an aqueous solution containing the synthetic resin pre-condensate and metal salt and finally heated to a temperature between 120‹ and 160‹ C. to cause reaction to take place. Alternatively, the synthetic resin pre-condensate may be added to the solution of binding agent together with an acid catalyst or compound yielding such catalyst when heated. After impregnation the fleece is heated to complete the reaction between the resin pre-condensate and the hydroxyl groups of the binding agent. The fleece is then impregnated with the solution of metal salt.</p> |
