CATIONIC PIGMENT AND METHOD OF PREPARATION THEREOF Russian patent published in 1998 - IPC

FIELD: pulp-and- paper industry. SUBSTANCE: invention relates to structured aggregate pigment products which are cationic and exhibit improved moisture retention when used in the stage of completing preparation of pulp. Invention consists in method of converting anionic pigments into cationic ones. Invention, in particular, focuses on structured aggregate pigment including clay and/or titanium dioxide or other components in the form of particles and functional microgel prepared from silicon- and aluminum- or zinc-containing gel-forming substances and a gel-forming agent such as calcium chloride. Pigment is converted into cationic form by adding effective amount of modified or unmodified epichlorohydrin-dimethylamine condensate to suspension of structured pigment. EFFECT: improved performance characteristics of pigments in paper production. 23 cl, 6 tbl