A process of making a silica-alumina composition having improved properties is provided. The process includes (a) mixing an aqueous solution of a silicon compound and an aqueous solution of an aluminum compound and an acid, while maintaining a pH of the mixed solution in a range of 1 to 3, and obtaining an acidified silica-alumina sol; (b) adding an aqueous solution of a base precipitating agent to the acidified silica-alumina sol to a final pH in a range of 5 to 8, and co-precipitating a silica-alumina slurry, wherein the base precipitating agent is selected from ammonium carbonate, ammonium bicarbonate, and any combination thereof; (c) optionally, hydrothermally aging the silica-alumina slurry to form a hydrothermally aged silica-alumina slurry; and (d) recovering a precipitate solid from the silica-alumina slurry or the hydrothermally aged silica-alumina slurry, wherein the precipitate solid comprises the silica-alumina composition.

A process of making a silica-alumina composition having improved properties is provided. The process includes (a) mixing an aqueous solution of a silicon compound and an aqueous solution of an aluminum compound and an acid, while maintaining a pH of the mixed solution in a range of 1 to 3, and obtaining an acidified silica-alumina sol; (b) adding an aqueous solution of a base precipitating agent to the acidified silica-alumina sol to a final pH in a range of 5 to 8, and co-precipitating a silica-alumina slurry, wherein the base precipitating agent is selected from ammonium carbonate, ammonium bicarbonate, and any combination thereof; (c) optionally, hydrothermally aging the silica-alumina slurry to form a hydrothermally aged silica-alumina slurry; and (d) recovering a precipitate solid from the silica-alumina slurry or the hydrothermally aged silica-alumina slurry, wherein the precipitate solid comprises the silica-alumina composition.

A process of making a silica-alumina composition having improved properties is provided. The process includes (a) mixing an aqueous solution of a silicon compound and an aqueous solution of an aluminum compound and an acid, while maintaining a pH of the mixed solution in a range of 1 to 3, and obtaining an acidified silica-alumina sol; (b) adding an aqueous solution of a base precipitating agent to the acidified silica-alumina sol to a final pH in a range of 5 to 8, and co-precipitating a silica-alumina slurry, wherein the base precipitating agent is selected from ammonium carbonate, ammonium bicarbonate, and any combination thereof; (c) optionally, hydrothermally aging the silica-alumina slurry to form a hydrothermally aged silica-alumina slurry; and (d) recovering a precipitate solid from the silica-alumina slurry or the hydrothermally aged silica-alumina slurry, wherein the precipitate solid comprises the silica-alumina composition.

Effect pigments based on Al.sub.2O.sub.3 flakes with high weather resistance and less photoactivity and to their use thereof in paints, industrial coatings, automotive coatings, printing inks, cosmetic formulations. The effect pigments have a ratio of the amount by weight of Al.sub.2O.sub.3 of the Al.sub.2O.sub.3 flake and the amount by weight of the metal oxide(s) of the coating layer(s) in the range of from 27:73 to 83:17 based on the total weight of the effect pigment.

Effect pigments based on Al.sub.2O.sub.3 flakes with high weather resistance and less photoactivity and to their use thereof in paints, industrial coatings, automotive coatings, printing inks, cosmetic formulations. The effect pigments have a ratio of the amount by weight of Al.sub.2O.sub.3 of the Al.sub.2O.sub.3 flake and the amount by weight of the metal oxide(s) of the coating layer(s) in the range of from 27:73 to 83:17 based on the total weight of the effect pigment.

Effect pigments based on Al.sub.2O.sub.3 flakes with high weather resistance and less photoactivity and to their use thereof in paints, industrial coatings, automotive coatings, printing inks, cosmetic formulations. The effect pigments have a ratio of the amount by weight of Al.sub.2O.sub.3 of the Al.sub.2O.sub.3 flake and the amount by weight of the metal oxide(s) of the coating layer(s) in the range of from 27:73 to 83:17 based on the total weight of the effect pigment.

Effect pigments based on Al.sub.2O.sub.3 flakes with high weather resistance and less photoactivity and to their use thereof in paints, industrial coatings, automotive coatings, printing inks, cosmetic formulations. The effect pigments have a ratio of the amount by weight of Al.sub.2O.sub.3 of the Al.sub.2O.sub.3 flake and the amount by weight of the metal oxide(s) of the coating layer(s) in the range of from 27:73 to 83:17 based on the total weight of the effect pigment.

The present invention relates to alumina flakes having a defined thickness and particle size distribution and to their use in varnishes, paints, automotive coatings, printing inks, masterbatches, plastics and cosmetic formulations and as substrate for effect pigments.

The present invention relates to alumina flakes having a defined thickness and particle size distribution and to their use in varnishes, paints, automotive coatings, printing inks, masterbatches, plastics and cosmetic formulations and as substrate for effect pigments.

The present invention relates to alumina flakes having a defined thickness and particle size distribution and to their use in varnishes, paints, automotive coatings, printing inks, masterbatches, plastics and cosmetic formulations and as substrate for effect pigments.