Abstract: In a method of producing TiO.sub.2 pigment particles a TiO.sub.a X.sub.b (OH).sub.c -based precursor is suspended in a liquid with or without fuel additives. The suspension is then sprayed to form droplets. The droplets are transported into a flow reactor with a carrier gas. The droplets are decomposed in the flow reactor at high temperatures to form TiO.sub.2 pigment particles which are collected downstream of the flow reactor. In a preferred embodiment, a colloidal suspension of an insoluble TiO(SO.sub.4).sub.b (OH).sub.c precipitate with suitable fuel additives was spray-calcined at 900.degree. to 1200.degree. C. to produce pigment-quality TiO.sub.2. The primary particle size of the TiO.sub.2 pigment particles is between 150-250 nm and the particles are minimally aggregated.
Type:
Grant
Filed:
July 12, 1996
Date of Patent:
November 10, 1998
Assignee:
Kemira Pigments, Inc.
Inventors:
Abhijit S. Gurav, Toivo T. Kodas, Bruce M. Anderson
Abstract: An ultrafine titanium dioxide powder is disclosed that can be produced by hydrothermal treating an amino titanium oxalate composition. Ultrafine titanium dioxide powders are useful in cosmetic and other applications for controlling exposure to ultraviolet (UV) light.
Abstract: Colored pigments are provided from the green-yellow to red spectrum based on oxide-nitrides with two or three different cations Q, R and S in the crystal lattice, wherein the nitrogen to oxygen atomic ratio is determinative for the color. These pigments crystallise in the pyrochlore, spinel or elpasolite structure. Pigments in the perovskite are as provided with increased color brilliance. The color of the pigments can be adjusted in a wide range of the color spectrum during their preparation within a substance class with the cations Q, R and S and while retaining the crystal structure, by increasing or lowering the atomic ratio N to O in the oxide-nitride and bringing about the required charge balancing by replacing an equivalent quantity of the cation Q with the valency q by a cation R with the valency q+1.
Abstract: A stable dark or moderately dark opaque exterior coating constituted of pentations and binder materials having low solar absorbing properties capable of visual and infrared camouflage. The pigmentations and binder materials may be selected for the proper optical qualities by previous testing before mixture and application as a coating.
Type:
Grant
Filed:
February 10, 1969
Date of Patent:
May 12, 1998
Assignee:
The United States of America as represented by the Secretary of the Navy
Abstract: An improved dye composition for use in coating tablets and the like is constituted by a stable, aqueous suspension containing a water-soluble, nontoxic dye, an opacifying agent which may be titanium dioxide or iron oxide an immobilizing agent for immobilizing the dye and preventing it from migrating when applied to a tablet or the like, the immobilizing agent being constituted by a nontoxic metal salt present in an amount of from approximately 0.1 to 10 equivalents of metal per mole of dye, and water. The suspension may also contain a film-forming, water-soluble or water-dispersible edible polymer and a plasticizer. These compositions are used in lieu of lake compositions to produce tablets and the like with uniform, non-mottled coatings.
Abstract: a process for the preparation of anatase titanium dioxide having a high surface area and suitable as a catalyst support is described.The process involves forming an aqueous dispersion of titanium dioxide at a pH less than 3 and preferably less than 1 and depositing a first coating of a hydrous oxide of an element which acts as a rutilisation inhibitor and a second coating of a phosphate on the particles of titanium dioxide.The product of the process has a high surface area which is retained on heating for long periods at high temperature.A novel product is particulate anatase titanium dioxide which has been coated with a rutile inhibitor and a phosphate, has a specific surface area of at least 50 m.sup.2 /g and retains at least 80% of its surface area after heating at 800.degree. C. for 7 days.
Abstract: An inorganic paint suitable for harsh environments, and particularly suitable as a thermal control coating for spacecraft, includes a mixture of 50% or more dry weight barium titanate (BaTiO.sub.3) pigment powder with a binder of an alkali metal silicate such as potassium silicate K.sub.2 SiO.sub.3 or sodium silicate Na.sub.2 SiO.sub.3. Instead of alkali metal silicate binder, a glass frit may be used, which when fused binds the pigment to the substrate. The coefficient of thermal expansion of the pigment is about 12.times.10.sup.-6 /.degree.C. The coefficient of thermal expansion of the paint is moved toward the coefficient of expansion of the substrate by addition of a filler consisting of magnesia to increase the paint's coefficient of expansion, or alumina and/or silica to decrease the paint's coefficient of expansion. The paint survives harsh environments, ultraviolet radiation and a fluence of charged particles, while maintaining a low solar absorptance and high thermal emittance.
Abstract: Zinc powder, which contains a coloring element, e.g., Ti, Mn, or V, is heated to a temperature of from 350.degree. to 700.degree. C. so as to oxidize the surface of the powder and hence to develop such colors as brown, navy blue, blue, greenish-brown, green, and coffee brown. The colored zinc powder is sprayed onto a steel, aluminum, or ceramic article to produce a colored article. The colored zinc powder is also used as a pigment.