Abstract: The invention relates to aqueous dispersions, characterized in that they comprise (c) at least one aqueous silicon dioxide dispersion with a mean particle diameter of the SiO2-particles of 1 to 400 nm and (d) at least one water-soluble hydroxyl-containing organic compound, to a process for their preparation and to their use in adhesive and coating formulations.

Abstract: A light-permeable heat-protection element including at least one support element and at least one protective coating containing a reaction product which includes an aqueous alkali silicate solution and aluminate-modified or borate-modified silicon dioxide.

Abstract: Process for preparing aqueous compositions, particularly aqueous dispersions based on silicon dioxide, and for preparing adhesive or coating formulations using the aqueous compositions as a component, and for production of adhesive layers and bonding of substrates coated on one side or both sides by spray application using the compositions.

Abstract: A process of preparing a silica sol is described. The process involves reacting a fresh sol with guanidine carbonate. The reaction may be conducted in the presence of a base (e.g., sodium water glass), and at a pH of from 8 to 12. The process of the present invention may also include concentrating steps. The silica sol prepared by the method of the present invention has a BET surface area of greater than or equal to 100 m2/g, and contains from 0.05 to 15% by weight of gaunidinium ions, based on the total weight of the silica gel.

Abstract: A process of preparing a silica sol is described. The process involves reacting a fresh sol with guanidine carbonate. The reaction may be conducted in the presence of a base (e. g. , sodium water glass), and at a pH of from 8 to 12. The process of the present invention may also include concentrating steps. The silica sol prepared by the method of the present invention has a BET surface area of greater than or equal to 100 m2/g, and contains from 0.05 to 15% by weight of gaunidinium ions, based on the total weight of the silica gel.

Abstract: Aqueous polymeric dispersions comprising a mixture of: (a) a component selected from the group consisting of polyvinylacetates, polyvinylacetate copolymers, and combinations thereof; and (b) SiO2 particles having an average particle diameter of 1 to 400 nm; their use as adhesives and coatings; processes for preparing such dispersions; and substrates coated and/or adhered therewith.

Abstract: A light-permeable heat-protection element including at least one support element and at least one protective coating containing a reaction product which includes an aqueous alkali silicate solution and aluminate-modified or borate-modified silicon dioxide.

Abstract: Aqueous polymer dispersions based on polychloroprene, and a process for their preparation and use. The aqueous polymer dispersions are produced from a polychloroprene dispersion having an average particle size of from 60 to 220 nm, and an aqueous silicon dioxide dispersion having an SiO2 particle diameter of from 1 to 400 nm.

Abstract: The invention relates to aqueous dispersions, characterized in that they comprise (c) at least one aqueous silicon dioxide dispersion with a mean particle diameter of the SiO2-particles of 1 to 400 nm and (d) at least one water-soluble hydroxyl-containing organic compound, to a process for their preparation and to their use in adhesive and coating formulations.

Abstract: The invention relates to aqueous compositions, particularly aqueous dispersions based on silicon dioxide, and to a method for the production and usage thereof as a component in the production of adhesive layers and for the bonding of the substrates coated on one side or both sides by spray application using the compositions.

Abstract: The invention relates to a process for producing a molding, characterized in that a silicatic solid is mixed with a solution comprising a first silicatic binder and the mixture is then press-molded, and the compression molding is then post-treated with a solution comprising a second silicatic binder, and to silicatic moldings obtainable by this process, and also to their use as construction material, insulator material, gasket material or fire-resistant material.

Abstract: Aqueous polymeric dispersions comprising a mixture of: (a) a component selected from the group consisting of polyvinylacetates, polyvinylacetate copolymers, and combinations thereof; and (b) SiO2 particles having an average particle diameter of 1 to 400 nm; their use as adhesives and coatings; processes for preparing such dispersions; and substrates coated and/or adhered therewith.

Abstract: The invention relates to a process for producing a molding, characterized in that a silicatic solid is mixed with a solution comprising a first silicatic binder and the mixture is then press-molded, and the compression molding is then post-treated with a solution comprising a second silicatic binder, and to silicatic moldings obtainable by this process, and also to their use as construction material, insulator material, gasket material or fire-resistant material.

Abstract: A process of preparing a silica sol is described. The process involves reacting a fresh sol with guanidine carbonate. The reaction may be conducted in the presence of a base (e.g., sodium water glass), and at a pH of from 8 to 12. The process of the present invention may also include concentrating steps. The silica sol prepared by the method of the present invention has a BET surface area of greater than or equal to 100 m2/g, and contains from 0.05 to 15% by weight of gaunidinium ions, based on the total weight of the silica gel.

Abstract: The invention relates to a process for producing a molding, characterized in that a silicatic solid is mixed with a solution comprising a first silicatic binder and the mixture is then press-molded, and the compression molding is then post-treated with a solution comprising a second silicatic binder, and to silicatic moldings obtainable by this process, and also to their use as construction material, insulator material, gasket material or fire-resistant material.

Abstract: Aqueous polymer dispersions based on polychloroprene, and a process for their preparation and use. The aqueous polymer dispersions are produced from a polychloroprene dispersion having an average particle size of from 60 to 220 nm, and an aqueous silicon dioxide dispersion having an SiO2 particle diameter of from 1 to 400 nm.

Abstract: There is provided a process for polishing monocrystalline semiconductor materials of silicon and germanium to a high degree of surface perfection comprising polishing the material with a modified colloidal silica sol having a pH between about 11 to 12.5 and composed of colloidal silica particles which are coated with chemically combined atoms of aluminum to give a surface coverage of about 1 to about 50 aluminum atoms on the surface per 100 silicon atoms on the surface of uncoated particles. The particles of the modified silica sol used in the process of the invention have a specific surface area of about 25 to about 600 square meters per gram with the silica concentration of the sol ranging from about 2 to about 50% by weight.

Abstract: In the preparation of dimethylamine-borane by reacting an alkali metal or alkaline earth metal borohydride with a dimethylammonium salt, the improvement which comprises effecting the reaction in a liquid mixture comprising dimethylamine as a solvent and an additional organic solvent.