| 摘要 |
A coating composition such as nitrocellulose lacquer or varnish incorporates a flatting pigment having non-settling properties obtained by grinding a dried precipitated hydrated silica and calcining it at a temperature between 400 DEG C. and 600 DEG C. so that the pigment consists of particles smaller than 10 microns in size having a bound water content below 2%. The calcination may be effected before or after the grinding. Advantageously, a wet precipitated hydrated silica is spray-dried to about 12% or less total moisture; the dried hydrated silica is milled and air classified to obtain material consisting entirely of particles smaller than 10 microns in size; and these particles are calcined at a temperature between 450 DEG C. and 550 DEG C. The pigment product so obtained exhibits outstanding non-settling flatting characteristics in nitrocellulose lacquer.
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