| abstract |
Cationically modified white pigments (W) in particulate form, essentially consisting of a particulate inorganic white pigment (M) of a particle size in the range of 0, 1 to 40 μm and an applied water soluble, cationic, crosslinked polymer (P A ) containing quaternary ammonium groups in salt form, obtainable by reaction of epichlorohydrin or of epichlorohydrin derivatives or precursors with amines, under conditions leading to at least partial crosslinking, optionally in combination with an anionic optical brightener (B) and where the molar ratio of (B) to (P A ) is such that the number of cationic charges of the total polymer (P A ) is higher than the number of anionic charges of the total anionic optical brightener (B), are surprisingly useful as cationic white pigments in various fields of technique, especially in papermaking. |