| 摘要 |
<p>Process comprises feeding two solutions concurrently to an aqueous suspension of material to be coated partic. mica having a temperature of about 50-100 degrees C and a pH between 0.5 and 3.5. The two solutions being (a) an aqueous 0.001 to 0.2 molar solution of a titanium salt having a content in free acid corresponding to a normality of 0.002 to 1.5; and (b) an aqueous 0.025 to 8 normal alkali metal base with the provision that the feeding of the alkali metal base is maintained so that it is just capable of neutralising the acid contained in the titanium salt solution as well as the acid produced during the reaction, and that the quantity of titanium salt added per minute is kept within the order of magnitude of about 0.01 x 20x10-5 moles/m3 of surface to be coated.</p> |
