Clariant Finance (bvi) Limited

Alec Stewart Tindal

Andrew Clive Jackson

John Martin Farrar

J&uuml;rg Heller

Mariela Gauto

The instant invention relates to storage stable aqueous solutions of stilbene optical brighteners with polyvinyl alcohols which can be directly used by the papermaker in that they may be diluted with water and/or be metered directly into a coating composition, to provide coated papers of a particularly high whiteness.

Aqueous solutions of optical brighteners

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 &#x3bc;m and an applied water soluble, cationic, crosslinked polymer (P) 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) is such that the number of cationic charges of the total polymer (P) 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.

Cationically modified white pigments, their production and use

The invention relates to an optical brightener mixture (W) comprising optical brighteners (A) of formula (Ia), and (B) of formula (Ib) and optionally (C) of formula (Ic) as defined herein, their concentrated aqueous solutions (S), their production and their use.

Optical brighteners compositions their production and their use

New water-soluble polycondensation products are obtained by reaction of polyfunctional amines with cyanamide, its derivatives or polymers in the presence of sulfamic acid. They are excellent fixing agents which improve fastness properties of dyeings with substantive dyestuffs on cellulose fiber materials, paper, board and non-wovens.

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Leeds, United Kingdom

Alec Stewart Tindal