Abstract: Process for preparing a dispersion comprising silicon dioxide particles and cationizing agents, by dispersing 50 to 75 parts by weight of water, 25 to 50 parts by weight of silicon dioxide particles having a BET surface area of 30 to 500 m2/g and 100 to 300 ?g of cationizing agent per square meter of the BET surface area of the silicon dioxide particles, wherein the cationizing agent is obtainable by reacting at least one haloalkyl-functional alkoxysilane, hydrolysis products, condensation products and/or mixtures thereof with at least one aminoalcohol and water; and optionally removing the resulting hydrolysis alcohol from the reaction mixture. Also the process for preparing the dispersion, wherein the cationizing agent comprises one or more quaternary, aminoalcohol-functional, organosilicon compounds of formula III and/or condensation products thereof, wherein Ru and Rv are independently C2-4 alkyl group, m is 2-5 and n is 2-5.

Abstract: Aqueous dispersion comprising hydrophobized silicon dioxide particles, comprising a. 50%-80% by weight of water, b. 10%-30% by weight of hydrophobized silicon dioxide particles, c. 5%-15% by weight of at least one alcohol alkoxylate of the general formula R1O((CH2)mO)nH, where R1 is a branched or unbranched alkyl or alkenyl radical having 10-25 C atoms, m is 2 or 3 and n is 10-50, d. 0.5%-5% by weight of at least one amine and/or amino alcohol having a molecular weight of less than 500 and e. 0%-1% by weight of N-methylpyrrolidone, all figures for weight percentages being based on the dispersion. Paint formulation comprising the dispersion.

Abstract: A hydrogel having a floatability where from 40% to 90% of a solution and/or suspension to be thickened are thickened starting from the surface of the liquid and the rest of the solution and/or suspension to be thickened is thickened starting from the bottom of the container, a process for preparing the hydrogel and also its use for absorbing blood and/or body fluids, especially in hygiene articles, or for thickening aqueous solutions and/or suspensions, especially for thickening medical wastes.

Abstract: Pyrogenic silicon dioxde powder with a BET surface area of 30 to 90 m2/g, a DBP index of 80 or less, a mean aggregate area of less than 25000 nm2 and a mean aggregate circumference of less than 1000 nm, wherein at least 70% of the aggregates have a circumference of less than 1300 nm, It is prepared by mixing at least one silicon compound in vapour form, a free-oxygen-containing gas and a combustible gas in a burner of known construction, igniting this gas mixture at the mouth of the burner and burning it in the flame tube of the burner, separating the solid obtained from the gas mixture and optionally purifying, wherein the oxygen content of the free-oxygen-containing gas is adjusted so that the lambda value is greater than or equal to 1, the gamma value is between 1.2 and 1.8, the throughput is between 0.1 and 0.3 kg SiO2/m3 of core gas mixture and the mean normalised rate of flow of gas in the flame tube at the level of the mouth of the burner is at least 5 m/s. The powder can be used as a filler.

Abstract: Comb polymers are used as dispersants to increase the stability of colloidal suspensions containing multivalent or high concentrations of monovalent ions. Stabilized colloidal suspensions and methods of forming stabilized colloidal suspensions are described, including suspensions containing ceramic precursors or bioactive agents useful in forming ceramic substrates or pharmaceutical compositions, respectively.

Abstract: The present invention relates to metallic sheets having an improved antimicrobial property and also related to a method of manufacturing such sheets. More particularly, it relates to the continuous coating on metallic sheets with a resin composition containing antimicrobial additives. The surface of the metallic article is afforded antimicrobial properties by coating a liquid dispersion or solution of fine particles made of an antimicrobial ingredient on the surface of the metallic sheet dispersed in a uniform layer and cured or dried to affix to the metallic surface. The inorganic antibacterial particles are metal component-supporting oxides and zeolite powders. The inorganic antibacterial core particles have at least a primary surface coating of at least one metal or metal compound having antimicrobial properties. Roll coaters apply the coating.

Abstract: At least a part of the antibacterial agent is distributed in the vicinity of the surface of a resin material. The antibacterial agent preferably contains an inorganic antibacterial agent, and more preferably contains metallic components having the antibacterial property. The metallic components available comprise one or more metals selected from the group of consisting of silver, copper, zinc, iron, gold, platinum, palladium, lead, tin, mercury, cadmium, chromium, nickel and cobalt. The inorganic antibacterial agents comprise one or more substances selected from the group consisting of soluble glass, zirconium phosphate, calcium phosphate, zeolite, silica gel, titanium oxide and porous ceramics.

Abstract: A method for production of high purity silica sols comprising the steps: (a) adding a phosphonic acid-based complexing agent to the silicic acid-containing solution forming complexes with metal cations present in said solution; (b) forming in said silicic acid-containing solution a precipitation containing phosphonic acid-based complexing agent and metal cations; (c) removing the precipitation from the solution; and, (d) polymerising the silicic acid in the solution to obtain a silica sol. The invention also relates to silica sols containing at least one phosphonic acid-based complexing agent.

Abstract: Provided is a cationic polymer-modified silica dispersion which comprises silica fine particles having an average particle diameter of less than 200 nm and a cationic polymer and which does not bring about coagulation of the silica particles. The above dispersion which is diluted to a solid concentration of 1.5% by weight is characterized by having a light scattering index (n value) of 2.0 or more. The above dispersion can be produced by oppositely-colliding a mixed solution obtained by mixing silica with a cationic polymer in a polar solvent at a treating pressure of 300 kgf/cm2 or more or passing it through an orifice under a condition that a pressure difference between the inlet side and the outlet side of the orifice is 300 kgf cm2 or more.

Abstract: Silica sols exhibiting desirable yield-dilatancy are fabricated. A mixture comprising silica, water, and a pH-adjusting agent is provided, and the mixture is shear-mixed. The desirable properties of the resultant sol are attained by using a concentration of pH-adjusting agent that provides a viscosity within a particular range during shear mixing. The requisite pH range, however, changes depending on the properties of the silica mixture. A discovered technique for determining this changing pH range is by selecting the pH based on the silica surface area per unit volume of the mixture.

Abstract: The invention relates to an aqueous silica-based sol comprising a nitrogen-containing organic compound and silica-based particles with a specific surface area of at least 300 square meters per gram of silica. The invention further relates to a process for the production of an aqueous silica-based sol comprising a nitrogen-containing organic compound which comprises incorporating a nitrogen-containing organic compound into a silica-based sol containing silica-based particles with a specific surface area of at least 300 square meters per gram of silica. The invention also relates to the use of an aqueous silica-based sol comprising a nitrogen-containing organic compound and silica-based particles with a specific surface area of at least 300 square meters per gram of silica as a flocculating agent in the production of pulp and paper and in water purification.

Abstract: The invention concerns a process for preparing organically modified aerogels, in which a) a silicic acid sol with a pH .ltoreq.4.0 is produced from an aqueous potassium silicate solution using at least one organic and/or inorganic acid; b) the resultant silicic acid sol is polycondensed by the addition of a base to form SiO.sub.2 gel; c) the gel produced in step b) is washed with an organic solvent until the water content of the gel is .ltoreq.5 wt %; d) the gel obtained in step c) is surface-modified with at least one C.sub.1-6 alcohol; and e) the surface-modified which are difficult to dissolve in the silicic acid sol. Before step b), the resultant salts, which are difficult to dissolve, are precipitated to the greates possible extent and separated from the silicic acid sol.