Abstract: The invention relates to a fluorescent brightener pigment and the use of said pigment, which is derived from formaldehyde, for improving the whiteness of paper or textiles, or for incorporation in detergent compositions.

Abstract: The invention relates to a fluorescent brightener pigment and the use of said pigment, which is derived from formaldehyde, for improving the whiteness of paper or textiles, or for incorporation in detergent compositions.

Abstract: A process for the preparation of azo dyes of formula ##STR1## wherein K is the radical of a coupling component of the benzene or naphthalene series or of the heterocyclic series, and the hydroxy group is attached to K adjacent to the azo group, X is hydrogen or nitro and M is an alkali metal ion, which process comprises coupling a diazo component of formula ##STR2## in the presence of one or more buffer mixtures and in the absence or presence of an alkali metal chloride, to a coupling component of formula ##STR3## in which formulae (2) and (3) K and X are as defined for formula (1). The present invention makes it possible to prepare the azo dyes in high yields.

Abstract: A process for controlling and optimizing chemical industrial processes for the preparation of dyes, fluorescent whitening agents and their intermediates, which process comprises controlling and optimizing those processes by differential analysis of the UV/VIS absorption spectra of at least one starting compound and of at least one reaction product. The advantage of this process is that the actual state of a process can be constantly measured, assessed, and used for feed-back and feed-forward control.

Abstract: Process for the preparation of azo dyes of the formula ##STR1## in which K is the radical of a coupling component of the benzene or naphthalene series or of the heterocyclic series in which the hydroxyl group is attached to K in a position adjacent to the azo group, X is hydrogen or nitro and M is an alkali metal ion or ammonium ion, which comprises coupling a diazo component of the formula ##STR2## in the presence of an alkali metal chloride and ammonium chloride with a coupling component of the formula (3) ##STR3## K and X in the formulae (2) and (3) being as defined under formula (1). The present invention allows the preparation of the said azodyes in high yields.