SURFACE-MODIFIED CALCIUM CARBONATE CONTAINING MINERAL AND ITS APPLICATION Russian patent published in 2017 - IPC C09C1/02 D21H17/00 

FIELD: chemistry.

SUBSTANCE: method of obtaining surface-modified globular spherical particles containing calcium carbonate is described, comprising the following stages: a) providing at least one water suspension of the mineral containing the calcium carbonate; b) providing a water-soluble acid selected from phosphoric or sulfuric acid; c) optional additional provision of gaseous CO₂ from an external source; d) bringing said water suspension of the mineral containing calcium carbonate of the stage (a) in contact with said acid of the stage (b) and with the specified CO₂ obtained in situ and/or introduced from an external source, of the stage (c), under conditions of stirring; e) optional dehydration of the water suspension, wherein at least one technological additive is introduced before, during or after bringing said water suspension of the mineral containing calcium carbonate of the stage (a) in contact with said acid of the stage (b) and with said CO₂ obtained in situ and/or introduced from an external source of the stage (c), wherein the technological additive is introduced during one or more stages in said water suspension of the mineral containing calcium carbonate, with the technological additive is added in amounts constituting up to 8 wt % based on the dry weight of the suspension, and said at least one technological additive is selected from the group comprising iron (II) sulfate, iron (III) sulfate, iron (II) chloride, iron (III) chloride, aluminum sulfate, and/or their hydrated forms, silicates, water-soluble cationic polymers, water-soluble amphoteric polymers, water-soluble nonionic polymers and combinations thereof. The water suspension of the spherical surface-modified mineral containing calcium carbonate, the surface-modified mineral containing calcium carbonate, and the use of water suspensions of the surface-modified mineral containing calcium carbonate, or dry spherical surface-modified mineral containing calcium carbonate, and the product selected from the paper, tissue paper, paper for digital photos, paints, coatings, adhesives, plastics or materials for purifying waste water, comprising a water suspension of the spherical surface-modified mineral containing calcium carbonate, or the dry spherical surface-modified mineral containing calcium carbonate, are described as well.

EFFECT: surface-modified mineral containing calcium carbonate for use in paints and coatings is obtained, which provides the matting effect and the smooth surface of a paint or coating at its low content.

32 cl, 3 dwg, 5 tbl