| abstract |
PURPOSE: To obtain a title composition with excellent chemical resistance useful as a paint or the like, by a method wherein alkali silicate and an org. compound capable of reacting with said alkali silicate to form silica sol are reacted in an aqueous slurry of ultramarine to precipitate fine amorphous silica onto a surface of ultramarine particle. n CONSTITUTION: An aqueous slurry of ultramarine of which pH is about 7W11, pref., about 9W11 and the concentration is generally 50W30g/l is prepared. On the other hand, a specific org. compound is added to an aqueous alkali silicate solution of which the concentration is 1W10wt% as SiO 2 to prepare a solution. A suitable org. compound is one having a capacity to form silica sol by reacting with alkali silicate, such as an org. phosphoric acid compound like trimethyl phosphate, an org. boric acid compound like ethyl borate, and a derivative like salts, esters, or amides of an org. acid, aldehyde, or peroxide. Subsequently, this solution is added to an aqueous slurry of ultramarine while pH is controlled to about 9W11 and temp. to above about 60°C and reacted to precipitate fine amorphous silica onto a surface of ultramarine particles. n COPYRIGHT: (C)1980,JPO&Japio |