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 m and an applied water soluble, cationic, crosslinked
polymer (PA) 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 (PA) is such that the number of cationic charges of the total
polymer (PA) 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.
