METHOD OF COATING SURFACE OF INORGANIC PARTICLES WITH SILICON DIOXIDE AND AT LEAST ONE ADDITIONAL INORGANIC COMPOUND (EMBODIMENTS) Russian patent published in 2019 - IPC C09C1/36 C09C3/06 

FIELD: chemistry.

SUBSTANCE: invention can be used in production of paper, plastics, during coating application. Method of depositing on the surface of inorganic particles in an aqueous suspension a dense layer of silicon dioxide and at least one additional layer of an inorganic compound involves depositing a separate dense layer of silicon dioxide on titanium dioxide particles in an aqueous suspension. Particles are separated from the suspension after application of the silicon dioxide layer, washed and subjected to thermal treatment in two stages. First heat treatment step is performed at temperature higher than 100 °C, and second stage at higher temperature from 200 °C to 850 °C. Particles are then reslurried to obtain a second aqueous suspension of particles and coated with at least one additional layer of inorganic compound. At least one additional layer of inorganic compound is made of oxides, hydroxides, carbonates, phosphates and sulphides or a combination thereof.

EFFECT: invention improves the pigment's dispersing ability and dispersibility and reduces acidic solubility thereof.

12 cl, 2 dwg, 1 tbl, 4 ex