TAPPI T 661 : OM 93

Deals with testing of synthetic silicate pigments for moisture, pH, viscosity, 325-mesh residue, and brightness. The term synthetic silicate pigments refers to a group of white pigments including the following: Products formed by the reaction of siliceous materials with a compound capable of forming an insoluble metal silicate. These silicates can be amorphous or crystal-line, depending upon the method of their preparation. Complex silicates of the type formed by the reaction of an alkali or alkaline earth compound and an aluminum compound with a siliceous material. Those materials whose principal constituent is hydrated silica formed by the separation of silica from one of its reactive compounds.