METHOD OF IMPROVING RHEOLOGICAL PROPERTIES OF WATER SUSPENSION OF PIGMENT, DISPERSANT AND ITS APPLICATION Russian patent published in 2014 - IPC C09D7/02 C09D17/00 D21H19/58 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of improving rheological properties of a water pigment suspension in compositions for paper coating. The method includes addition of a dispersant to the water phase of the suspension, which does not contain or does not yet contain pigment particles. The dispersant represents water polymer dispersion with content of the solid substance 10-50%. The polymer is represented by styrene-acrylate copolymer, obtained by copolymerisation of styrene, substituted styrene or their mixture and C₁-C₄ alkylacrylates, C₁-C₄ alkylmethacrylates or their mixture in the presence of starch or dextrin. The invention also relates to the dispersant for suspension of a pigment, containing the first and second components. The first component contains the said styrene-acrylate copolymer. The second component contains an ordinary dispersant such as polyacrylate with a straight chain. Weight ratio between the first and second component is in the range of 50:50-99:1.

EFFECT: invention ensures improvement of rheological properties and high-shear characteristics of water suspension of a pigment in compositions for paper coating.

10 cl, 1 tbl, 4 ex