Patent ID: 6911116

Claim:
A cationically modified white pigment (W) in particulate form, consisting essentially of: a particulate inorganic white pigment (M) of a particle size in the range of 0,1 to 40 μm; an applied water soluble, cationic, crosslinked polymer (P A ) containing quaternary ammonium groups in salt form, where (P A ) is a polymer obtained by crosslinking with an at least bifunctional secondary or tertiary amine the chloroterminated reaction product of an oligofunctional aliphatic alcohol with epichlorohydrin and optionally further reacting any non reacted chlorine with a tertiary amine under conditions leading to at least partial crosslinking, 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).