Abstract: 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.

Abstract: 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.

Abstract: The instant invention relates to storage stable aqueous optical brightener/PVOH solutions of low viscosity which may be used directly by the papermaker, in that they can be metered by pump directly into a coating composition, and which provide coated papers of a surprisingly high whiteness

Abstract: The instant invention relates to storage stable aqueous optical brightener/PVOH solutions of low viscosity which may be used directly by the papermaker, in that they can be metered by pump directly into a coating composition, and which provide coated papers of a surprisingly high whiteness

Abstract: The instant invention relates to a process for the rating of optically brightened paper by visually assessing the paper to ensure that it is white, followed by measurement on a highly accurate single reference spectrophotometer to generate a simple rating, which can then be used to inform the consumer or end user of the whiteness level of the paper. The whiteness level is controlled during production by an audited quality system to ensure each sample of paper is identical in rating.

Abstract: 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.

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 ?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.

Abstract: 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.

Abstract: 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.

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 &mgr;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.