Abstract: The invention relates to a process for producing a titanium dioxide pigment obtainable by the sulfate process with a narrow particle size distribution, the pigment itself, and the use of said pigments in coatings and printing inks.

Abstract: The invention relates to a method for coating the surface of inorganic particles in an aqueous phase, particularly of titanium dioxide pigment particles, with a dense skin of silicon dioxide and at least one further inorganic compound, particularly with aluminum oxide, where the coating largely consists of separate layers. Titanium dioxide pigment particles, treated with SiO2 and Al2O3 according to the invention, are characterized by improved tinting strength, reduced acid solubility and an isoelectric point shifted towards higher pH values.

Abstract: The invention relates to a process for producing a titanium dioxide pigment obtainable by the sulfate process with a narrow particle size distribution, the pigment itself, and the use of said pigments in coatings and printing inks.

Abstract: The invention relates to a method for coating the surface of inorganic particles in an aqueous phase, particularly of titanium dioxide pigment particles, with a dense skin of silicon dioxide and at least one further inorganic compound, particularly with aluminium oxide, where the coating largely consists of separate layers. Titanium dioxide pigment particles, treated with SiO2 and Al2O3 according to the invention, are characterised by improved tinting strength, reduced acid solubility and an isoelectric point shifted towards higher pH values.

Abstract: The invention relates to a method for the surface treatment of inorganic pigment particles with agglomerates of fine primary particles or single crystals of inorganic compounds, particularly of oxides or sulphates. The method is characterized in that the inorganic compounds are first precipitated from an aqueous solution under suitable pH conditions in a separate vessel in the form of fluffily structured agglomerates and/or single crystals. The precipitation product is subsequently added to an aqueous suspension of inorganic pigment particles. The method is particularly suitable for the surface treatment of titanium dioxide particles, in order to achieve high hiding power or high opacity when used in emulsion paints or laminates.

Abstract: The invention relates to a method for the surface treatment of inorganic pigment particles with agglomerates of fine primary particles or single crystals of inorganic compounds, particularly of oxides or sulphates. The method is characterized in that the inorganic compounds are first precipitated from an aqueous solution under suitable pH conditions in a separate vessel in the form of fluffily structured agglomerates and/or single crystals. The precipitation product is subsequently added to an aqueous suspension of inorganic pigment particles. The method is particularly suitable for the surface treatment of titanium dioxide particles, in order to achieve high hiding power or high opacity when used in emulsion paints or laminates.

Abstract: The invention relates to a method for the surface treatment of inorganic pigment particles with agglomerates of fine primary particles or single crystals of inorganic compounds, particularly of oxides or sulphates. The method is characterized in that the inorganic compounds are first precipitated from an aqueous solution under suitable pH conditions in a separate vessel in the form of fluffily structured agglomerates and/or single crystals. The precipitation product is subsequently added to an aqueous suspension of inorganic pigment particles. The method is particularly suitable for the surface treatment of titanium dioxide particles, in order to achieve high hiding power or high opacity when used in emulsion paints or laminates.

Abstract: The invention relates to a method for the surface treatment of inorganic pigment particles with agglomerates of fine primary particles or single crystals of inorganic compounds, particularly of oxides or sulphates. The method is characterized in that the inorganic compounds are first precipitated from an aqueous solution under suitable pH conditions in a separate vessel in the form of fluffily structured agglomerates and/or single crystals. The precipitation product is subsequently added to an aqueous suspension of inorganic pigment particles. The method is particularly suitable for the surface treatment of titanium dioxide particles, in order to achieve high hiding power or high opacity when used in emulsion paints or laminates.

Abstract: A method of predicting photostability of coatings with various dopants on titanium dioxide pigment particles is disclosed. Calculations of the density of states show that a doped coating which reduces the density of states near the band edge or increases the density of states within the band gap of the pigment particles increases the photostability of the doped pigment.

Abstract: A method of predicting photostability of coatings with various dopants on titanium dioxide pigment particles is disclosed. Calculations of the density of states show that a doped coating which reduces the density of states near the band edge or increases the density of states within the band gap of the pigment particles increases the photostability of the doped pigment.

Abstract: The invention relates to a rutile titanium dioxide pigment for use in decorative laminating papers that yields higher opacity of the papers compared to the prior art, as well as a method for its manufacture. The pigment displays a surface coating that contains aluminum phosphate, aluminum oxide, silicon oxide and titanium oxide. The silicon oxide is precipitated in fluffy form. The coated particles display a BET value of at least 15 m2/g. The manufacturing method is characterized in that an aluminum and a phosphorus component are first added to a TiO2 suspension. Thereafter, an alkaline silicon component, an acid-reacting titanium component and, optionally, a further pH-regulating component are added, the pH value being set in the range from 4 to 9 in this context.

Abstract: A method of predicting photostability of coatings with various dopants on titanium dioxide pigment particles is disclosed. Calculations of the density of states show that a doped coating which reduces the density of states near the band edge or increases the density of states within the band gap of the pigment particles increases the photostability of the doped pigment.

Abstract: A method of predicting photostability of coatings with various dopants on titanium dioxide pigment particles is disclosed. Calculations of the density of states show that a doped coating which reduces the density of states near the band edge or increases the density of states within the band gap of the pigment particles increases the photostability of the doped pigment.

Abstract: The invention relates to a weather resistant titanium dioxide pigment with good optical properties having a SiO2 dense skin doped with metal atoms. Particularly suitable elements for doping are tin, zirconium and titanium. The SiO2 dense skin is composed of multiple layers whereby the innermost layer does not contain any significant quantity of metal atoms. The coating according to the invention is produced by adding the components to the alkaline suspension (pH at least 9) one after the other with a sliding pH. Complete formation of the doped SiO2 dense skin requires that the pH subsequently be lowered to below 9. The pigment is particularly suitable for use in surface coatings and plastics.

Abstract: A method for the agitator milling of solid particles, particularly of titanium dioxide, where the suspension with a maximum particle size of 2 ?m is milled in closed-circuit mode and subjected to continuous classification by sedimentation in a tank after each pass through the mill. The method results in milled solid particles with narrower particle size distributions, particularly titanium dioxide pigments with improved optical properties, such as tinting strength and gloss.

Abstract: A coated titanium dioxide pigment with good opacity and simultaneously good retention for use in decorative laminating paper characterized by a surface coating containing aluminum oxide phosphate and attached hollow bodies, e.g., hollow microbodies. A manufacturing method is characterized in that an aluminum containing component and a phosphorus containing component are first added to a TiO2 suspension, during which time the pH value does not drop below 10. The hollow bodies are subsequently added, followed by addition of at least one acidic component, as a result of which the pH value of the suspension is lowered to the range from about 4 to 9. In an alternative embodiment of the method, the suspension has a pH value of under 4 at the time of addition of the aluminum containing component and a phosphorus containing component.

Abstract: A method and material for improved TiO2 pigment for paper and laminates is described. Phosphorous, titanium, and aluminum compounds are successively added to a TiO2 pigment suspension. Resulting pigments show improved greying resistance and hiding power over prior art pigments, and show improved results as pigments in tests of paper and laminates.

Abstract: The invention relates to a jet mill of modular design for the comminution of powdery materials. An inner pulverizing casing made entirely of wear-resistant material is freely mounted in an outer casing pressure vessel.

Abstract: The invention relates to a method for the surface treatment of a titanium dioxide that leads to pigments with improved retention and improved opacity, where consistently high opacity can be obtained using less pigment. The method is characterised in that an aluminium component and a phosphorus component are first added to a TiO2 suspension, during which process its pH value does not drop below 10. The pH value of the suspension is subsequently lowered to below 9 by adding an acid component. The pigment produced by the method according to the invention is eminently suited to use in decorative laminating paper.

Abstract: The invention relates to a method for the post-treatment of titanium dioxide, in order to produce particularly weather-resistant titanium dioxide pigments with good optical properties. The method is characterized in that, together with the hydrous oxides of tin and zirconium, at least one other from the group comprising aluminium, silicon and titanium is additionally precipitated onto the particle surface. The post-treatment components are added to the aqueous TiO2 suspension either in the acidic range (pH value of 3 at most) or in the alkaline range (pH value of 10 at least). The pH value is subsequently set to between 6 and 8. Final tempering of the pigment at elevated temperatures from over 125° C. to up to 500° C. can improve the tone b. The pigment is particularly suitable for use in paints, coatings and plastics.