Millennium Inorganic Chemicals, Inc.

Cristal Usa, Inc.

Scm Chemicals, Inc.

Millenium Inorganic Chemicals, Inc.

Tronox LLC

Fu-Chu Wen

Robert J Kostelnik

Deborah E Busch

Duen-Wu Hua

Duen-Wh Hua

Thomas Messer

David E Bell

Ling Zhou

Brian David Kiessling

Mark Banash

Richard L Fricker

Robert Provins

David Edwin Bell

Deborah L Busch

A composition includes polymer and dispersed infrared-reflective clusters of titanium dioxide primary particles. The titanium dioxide primary particles are cemented together with precipitated silica and/or alumina to form clusters. The titanium dioxide primary particles have an average particle diameter in the range of from about 0.15 to about 0.35 micron, while the clusters of titanium dioxide primary particles have an average cluster diameter in the range of from about 0.38 to about 5 microns and a geometric standard deviation (GSD) in the range of from about 1.55 to about 2.5.

Infrared-reflective coatings

In various embodiments, methods and compositions are provided comprising titanium dioxide and silica spacers having improved light stability for use in paper, plastic and paints.

Titanium dioxide pigment having improved light stability

The present invention provides methods and compositions comprising inorganic solids for use as pigments in paints, papers and plastics.

Inorganic particles and methods of making

A titanium dioxide compound was isolated from a rare type of naturally occurring ore. Processes for efficiently isolating and obtaining these TiO compounds, as well as methods for using them have been developed. These TiO compounds may be used directly in applications such as paper, plastics and paints without being subjected to the chloride or sulfate processes. Also they made be used as a feedstock for the chloride or sulfate processes. In order to obtain these TiO compounds, one may grind or pulverize the naturally occurring ore, disperse it in a solution or suspension, and process it by selective flocculation or aqueous biphasic extraction.

TiO2 compounds obtained from a high silica content ore

The present invention provides slurries and methods of making slurries having improved stability comprising below about 78 weight-percent rutile titanium dioxide based on the total weight of the slurry, an amorphous alumina compound surface treated titanium dioxide, a polyacrylic acid dispersing agent having a molecular weight in the range of from about 2,000 to about 5,000 that is neutralized with a neutralizing agent having a monovalent group, and water; wherein the slurry has a pH of from about 6 to about 8. The slurries of the present invention resist gel formation.

Titanium dioxide slurries having improved stability

The present invention discloses high solids slurries of anatase titanium dioxide pigment comprising greater than about 75% by weight of anatase TiO pigment dispersed in water. A process for producing the slurries of the present invention is disclosed which comprises the steps of a) dry milling the anatase titanium dioxide pigment, preferably by pressure rolling, and b) mixing the dry milled pigment with water in the presence of an acrylic acid dispersant.

Very high solids TiO2 slurries

The present invention discloses high solids slurries of anatase titanium dioxide pigment comprising greater than about 75% by weight of anatase TiO,pigment dispersed in water. A process for producing the slurries of the present invention is disclosed which comprises the steps of a) dry milling the anatase titanium dioxide pigment, preferably by pressure rolling, and b) mixing the dry milled pigment with water in the presence of an acrylic acid dispersant.

The present invention discloses high solids slurries of sulfate process, anatase titanium dioxide pigment. The improvements of these slurries over those of the prior art are improved slurry stability, tolerance to calcium and magnesium ions, foaming tendencies and reduced tendency to flocculate. The slurries of the present invention are comprised of at least 65% by weight of anatase TiO.sub.2 pigment produced by the sulfate production process dispersed in water containing a sufficient quantity of a dispersing agent selected from the group consisting of acrylic acid homopolymers and copolymers that are predominantly acrylic acid and contain at least one comonomer selected from the group consisting of maleic acid, methacrylic acid, itaconic acid, crotonic acid, fumaric acid, acrylamide, acrylonitrile, ethylene, propylene, styrene and esters of the above acids, which have been partially or completely neutralized with a neutralizing agent having a monovalent group and at least one neutralizing agent having a polyvalent group. A process for producing the slurries of the present invention is disclosed and comprises the steps of a) introducing the dispersing agent into water, b) adjusting the pH to a value greater than 7, c) adding the TiO.sub.2, with adequate mixing to break up large agglomerates, and, optionally, d)grinding in the presence of a suitable grinding medium to achieve the desired mean particle size for pigmentary applications.

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Severna Park, MD, United States of America

Fu-Chu Wen