| 摘要 |
1292408 Microcapsules NATIONAL CASH REGISTER CO 21 April 1971 [27 May 1970] 10393/71 Heading B8C Microcapsules are prepared by dispersing a water-insoluble core material in an aqueous solution of a water-soluble silicic acid or silicate capable of forming an aqueous solution or sol and adding a polyhydric alcohol thereto with agitation. A liquid phase composed of a complex of the silicic material and the polyhydric alcohol is formed and encapsulates the particles. The capsule walls may be hardened by addition of an inorganic salt which will react with the wall material to form a solid silicate salt, e.g. Al 2 (SO 4 ) 3 , MgSO 4 , CaCl 2 , MgBr 2 or iron chloride. The preferred polyhydric alcohol is polyethylene glycol of M.W. 400 to 6000. Glycols and glycerols may also be used. Specific examples relate to the encapsulation of aluminium particles, a hydrocarbon oil and microcapsules of butyl acetate in a gelatine mantle. |
