| 摘要 |
PROBLEM TO BE SOLVED: To provide a colloidal silica useful for an ink absorbing filler for printing papers, a spreading property improving agent for paint, a hydrophilic coating material for various material surfaces, a high strength binder, a high purity silica gel, a raw material for high purity ceramics, a binder for a catalyst, a polishing material for an electronic material and the like. SOLUTION: The colloidal silica is produced by using an active silicic acid as a raw material in the presence of benzotriazole, and contains benzotriazole in the liquid phase and a group of non-spherical heteromorphic silica particles which has a major axis/minor axis ratio by a transmission electron microscope in the range of 1.2-15 and an average value of the major axis/minor axis ratio of 1.5-10. This can be produced by contacting an aqueous alkali silicate solution with a cation exchange resin to prepare an aqueous active silicic acid solution, thereafter adding benzotriazole and an alkali agent to the aqueous active silicic acid solution to be made alkaline, and then heating to form silica particles and subsequently growing up the silica particles by a buildup technique. COPYRIGHT: (C)2011,JPO&INPIT |
