Alkanolammonium-containing triazinyl flavonate whiteners

Abstract

A process for whitening paper in a size press includes contacting a cellulose sheet with a size press liquor that contains a surface size and a particular whitener containing sulfonate groups and cations, M, wherein at least 10% of all cations M have the formula in which R5 to R7, independently of one another, denote hydrogen, a C1-C4-alkyl radical or an optionally further substituted C2-C4-hydroxyalkyl radical, and R8 denotes an optionally further substituted C2-C4-hydroxyalkyl radical. The process provides superior paper whitening compared to a corresponding process in which the whitener cations are all sodium or potassium ions.

Dependencies are inferred from the claim text.