Pigmentos compuestos que contienen hidróxido de aluminio y procedimiento para su preparación

• Main Authors: WILKENHOENER, Uwe, MERSCH, Frank
• Format: Patent
• Language: Spanish
• Published: 05.08.2021
• Subjects: ADHESIVES; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; COMPOSITIONS BASED THEREON; CORRECTING FLUIDS; DYES; FILLING PASTES; INKS; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; POLISHES; PREPARATION OF CARBON BLACK; THEIR PREPARATION OR CHEMICAL WORKING-UP; TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS,TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; USE OF MATERIALS THEREFOR; WOODSTAINS

Procedimiento para preparar partículas de pigmento compuesto que contienen hidróxido de aluminio que presentan un contenido en hidróxido de aluminio de al menos el 20% en peso, preferiblemente de al menos el 40% en peso, en donde se proporciona una solución acuosa alcalina de aluminato de sodio con un valor de pH de al menos 12, posteriormente se añaden partículas de pigmento inorgánico y el valor del pH de la solución se reduce a dentro del intervalo de <8 a >3, de modo que el hidróxido de aluminio en partículas precipita y se forman partículas de pigmento compuesto que contienen hidróxido de aluminio, y las partículas compuestas finalmente se separan. The invention relates to the manufacture of composite pigments containing aluminum hydroxide, and their use for improving the pigment light-scattering efficiency in coatings, plastics, paper and laminates. The composite pigment particles contain pigment particles such as titanium dioxide and precipitated aluminum hydroxide and are manufactured by in-situ precipitation of aluminum hydroxide in an aqueous pigment particle suspension. Use of the composite pigment particles according to the invention, based on titanium dioxide, permits savings on pigment with little or no loss of optical properties. Alternatively, if the pigment content remains unchanged, it is also possible to achieve better optical properties.