The invention relates to a process for preparing self-binding pigment particle suspensions, to a self-binding pigment particle suspension as well as to a paper product comprising self-binding pigment particles and to the use of the self-binding pigment particle suspension as filler material.

Provided is an inorganic oxide dispersion (sol) in which inorganic oxide particles are dispersed in silicone oil.

The present invention relates to -Al.sub.2O.sub.3 flakes prepared by a process comprising (1) preparation of an aqueous solution of at least one water-soluble and/or insoluble aluminum salt which optionally contains at least one sulfate compound, (2) adding a basic solution and optionally at least one dopant to the aluminum salt solution (1), (3) drying of the obtained gel, followed by calcination to obtain Al2 03 flakes and alkali salts in a molten salt, and (4) removal of the water soluble parts of the calcined molten salt obtained in step (3).

Obtaining a natural or synthetic agalmatolite containing a narrow and controlled particle distribution range, can be obtained by a high-energy million process associated to a high performance aerodynamic particle size analysis, the final use of this product being the paint industry, imparting texture, silky luster, fineness, opacity, wet scrub resistance and whiteness to the paint.

Composite pigments are provided which comprise a mineral pigment (such as kaolin clay, titanium dioxide, talc, mica or a mixture of two or more of these mineral pigments) and calcium carbonate precipitated in-situ on the surfaces of the particles of the mineral pigment.

The present invention relates to the processing of natural titanium-containing feedstock, mainly ilmenite concentrate, including ilmenite ores with a low TiO.sub.2 content, into products with high added value without generating any liquid or solid waste. The method according to the invention comprises the following stages: digesting ilmenite concentrate, processing the solid residue following ilmenite concentrate digestion, hydrolysis of titanium oxychloride, washing titanium oxides/hydroxides precipitate from impurities, calcination of titanium oxides/hydroxides precipitate, precipitation of iron hydroxides to obtain black, red and yellow iron oxide pigments, processing the mother liquor containing calcium chloride, regeneration of hydrogen chloride from ammonium chloride solution, obtaining ammonium sulfate and ammonium sulfate crystallization, obtaining crystalline ammonium chloride. The resulting products are pigments, pigment fillers, mineral fertilizers, construction materials, raw materials for the production of metals, and other products; they are used in various fields of application such as paint and coatings industry, pulp and paper industry, in the production of plastics, in metallurgy, in agricultural, construction industries and others.

Core/shell-type metal oxide particles are suitably used for optical thin film, such as a hard coat, ultraviolet blocking layer, anti-reflection film or diffractive optical element material, have excellent light resistance, transparency and processing properties, e.g. imprinting, and have a high refractive index; and a method for producing the same. In these particles (C), the surface of metal oxide particles (A1) serving as a core is coated with a metal oxide (A2) containing titanium oxide, and the coating layer is further coated with a metal oxide (A3) having a metal oxide other than titanium oxide as the main component. The average primary particle diameter of the core/shell-type metal oxide particles (C) is 10 to 20 nm, and the metal oxide particles (A1) are rutile-type titanium oxide containing at least one selected from the group consisting of tin oxide, zirconium oxide, zinc oxide, iron oxide, nickel oxide and aluminium oxide.