Tronox LLC

Kerr-mcgee Chemical, LLC

Daniel H Craig

Venkata Rama Rao Goparaju

Jeffrey D Elliott

Mark D Westmeyer

Harmon E Ray

Simplified and improved processes are provided for manufacturing titanium dioxide pigments including a surface treatment whereby a plurality of inorganic oxides or a combination of one or more inorganic oxides with one or more inorganic phosphates are applied to a titanium dioxide base pigment. Aqueous acid-soluble sources of the desired inorganic oxides and/or phosphates are predissolved in an aqueous acid, and these can be added on a batch wise or more preferably on a continuous basis to an alkaline slurry containing the titanium dioxide base pigment and to which aqueous alkaline-soluble sources of the desired inorganic oxides are being or have been added previously. Co-precipitation of the oxides and/or oxides and phosphates is then accomplished by an adjustment of the pH, to provide a surface treated pigment with excellent homogeneity of the deposited mixed oxides and/or oxides and phosphates.

Making co-precipitated mixed oxide-treated titanium dioxide pigments

An improved process for making an organosilicon compound surface-treated titanium dioxide material, comprising (a) forming a mixture of the titanium dioxide material in water, (b) wet milling the mixture, (c) adjusting the pH of the slurry resulting from step (b) to between about 5.0 and about 8.5, (d) after step (c), removing the titanium dioxide material from the mixture by vacuum or pressure filtration, (e) after step (d), washing the titanium dioxide material so removed, (f) after step (e), converting the washed titanium dioxide material to a fluid dispersion having a pH of from about 3.5 to less than about 7 via addition of a fluidizing agent comprising a water-soluble monoprotic acid, (g) after, or concurrently with, step (f), adding to the resulting dispersion of titanium dioxide material an organosilicon compound, with mixing, and (h) spray drying the dispersion of the washed titanium dioxide material resulting from step (g) to yield a dry titanium dioxide pigment powder.

Process for the manufacture of organosilicon compound-treated pigments

An improved process is described for manufacturing zirconia-treated titanium dioxide pigments, wherein the zirconia treatment is accomplished in the process of fluidizing a titanium dioxide filter or press cake and then drying the same, through the addition to the filter or press cake of one or more alkaline water-soluble zirconium reagents selected from ammonium zirconyl carbonate, the water-soluble ammonium zirconyl carboxylates and mixtures of these. Aqueous solutions of such zirconium reagents, in addition to being effective for imparting a zirconia surface treatment to the titanium dioxide materials, also prove to be effective fluidizing agents for forming high solids dispersions of the zirconia-treated titanium dioxide pigment materials which can be spray dried without substantial dilution and excessive energy requirements.

Process for manufacturing zirconia-treated titanium dioxide pigments

Inorganic pigments treated with at least one N,N,N-trialkyl quaternary amino acid inner salt possess improved processibility and dispersibility in thermoplastic materials, and impart improved properties to thermoplastic compositions containing said surface-treated pigments.

Surface treated pigments

Inorganic pigments, having deposited on the pigment surface at least one alkenyl- or alkyl-substituted succinic anhydride and at least one organic polyol, possess improved processibility and dispersibility in thermoplastic materials, and impart improved properties to thermoplastic compositions containing said surface-treated pigments.

Surface-treated pigments

Inorganic pigments treated with at least one amide of a fatty acid and an aliphatic amine possess improved processibility and dispersibility in thermoplastic materials, and impart improved properties to thermoplastic compositions containing said surface-treated pigments.

Inorganic pigments treated with one or more of the &#x3b1;,&#x3b1;-dialkyl substituted linear or branched carboxylic acids and the salts thereof possess improved processibility and dispersibility in thermoplastic materials, and impart improved properties to thermoplastic compositions containing said surface-treated pigments.

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Edmond, OK, United States of America

Daniel H Craig