Process for controlling and optimising industrial processes for the preparation of dyes, fluorescent whitening agents and their intermediates
AssigneeCiba-Geigy Corporation
InventorsHorst Langfeld, Roland Minges, Claudio Puebla, Wilhelm Schmidt
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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.
Claims15
A process for on-line controlling and optimising industrial chemical metallising and condensation reactions for the preparation of dyes using the method of UV/VIS spectroscopy, which process comprises recording the UV/VIS absorption spectra of at least one starting compound and of at least one reaction product, determining spectroscopically in the course of the preparatory process at specific time intervals the present state of the reaction by differential analysis of the instant UV/VIS absorption spectrum of the reaction mass and of the UV/VIS absorption spectrum of at least one reaction product, and from this difference, if necessary by changing one or more of the parameters of temperature, pressure, amount of the starting materials, reaction time or pH value, controlling the difference between said last two spectra towards zero.
Dependencies are inferred from the claim text.