METHOD FOR PRODUCING PIGMENTS FOR NATURAL PAINTS Russian patent published in 2018 - IPC C09B61/00 C09C1/42 

FIELD: chemistry.

SUBSTANCE: method includes preparation of clay, isolation of anthocyans, intercalation of anthocyans into clay, separation of sediment and drying. Isolation of anthocyans is carried out by extraction with 0.1 M aqueous solution of hydrochloric acid to a concentration of about 0.5 wt % in terms of cyanidin-3-glucoside. Preparation of clay is carried out by processing with 1 M hydrochloric acid solution, 0.1 M solution of hydrochloric acid, centrifugation and drying at 50°C. Intercalation is carried out by stirring the anthocyanin extract with clay in a weight ratio of 1:100 to 1:10000 for 30 minutes at room temperature. Drying of the precipitate is carried out at a temperature of not higher than 35°C.

EFFECT: invention provides preservation of anthocyans in intercalates after a year of storage using a simple technology and available substances.

4 dwg, 1 ex