Non-settling coating composition and flatting pigment

Abstract

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.degree. C. and 600.degree. 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.degree. C. and 550.degree. C. The pigment product so obtained exhibits outstanding non-settling flatting characteristics in nitrocellulose lacquer.

Dependencies are inferred from the claim text.