METHOD OF PREPARING SUBSTANCE FOR PIGMENT TREATMENT Russian patent published in 2002 - IPC

FIELD: inorganic chemistry, chemical technology. SUBSTANCE: method of preparing substance comprising aluminium compound for surface treatment of pigments involves precipitation of Al₂O₃•3H₂O, precipitate washing out from water-soluble salts and heat treatment. Precipitation of Al₂O₃•3H₂O is carried out by passing carbon dioxide gas through aluminate solution of one or some alkaline metals and treatment of Al₂O₃•3H₂O is carried out at temperature from 300 to 900 C in the presence of calcium and/or magnesium compounds taken in concentration from 0.05 to 3 wt.% as measured for CaO and/or MgO of Al₂O₃. amount. Invention ensures to obtain substance modifying pigment thus to provide significant decrease of their photochemical activity, dispersing capacity increase and decrease of covering power index. Invention can be used in treatment of pigments, mainly titanium dioxide, and lipothone, lead crown and iron oxide pigments also. EFFECT: improved method of preparing. 2 tbl, 5 ex