| 摘要 |
1,254,229. Sodium alumino silicate. FARBENFABRIKEN BAYER A.G. 19 Aug., 1969 [21 Sept., 1968], No. 41354/69. Heading C1A. Sodium aluminium silicate is produced continuously by reacting sodium silicate solution, 0À5-2À0 N with an Na 2 O : SiO 2 ratio of 1 : 2 to 1:4, with an aluminium salt solution equivalent to 8-35 gm/e Al 2 O 3 , at 40-80‹ C., such that the average residence time in the reactor is 50-900 seconds, and the pH is 6-10, followed by separation of the product, washing, drying and grinding. When the product is to be used as a strengthening filler for rubber the pH range is preferably 8-10, whilst for use as a micro extender in paper, the range 6-9 is preferred. The preferred Na 2 O : SiO 2 ratio is 1 : 3À3. The reaction mixture is subjected to high shear forces, and the product dried at less than 300‹ C. |
