Abstract: An aqueous oil-in-water emulsion containing a propylethoxysilane oligomer mixture or a mixture of a propylethoxysilane oligomer mixture and octyltriethoxysilane in a weight ratio of 3:1 to 1:3, at least one emulsifier or an emulsifier system, at least one content of a 2-aminoethanol and water is used as an addition in the production of hydraulically setting cement mixtures such as mortar, screed or concrete for reduction of the shrinkage characteristics.

Abstract: An aqueous oil-in-water emulsion containing a propylethoxysilane oligomer mixture or a mixture of a propylethoxysilane oligomer mixture and octyltriethoxysilane in a weight ratio of 3:1 to 1:3, at least one emulsifier or an emulsifier system, at least one content of a 2-aminoethanol and water is used as an addition in the production of hydraulically setting cement mixtures such as mortar, screed or concrete for reduction of the shrinkage characteristics.

Abstract: Water-based organopolysiloxane-containing compositions which are essentially free from organic solvents, have a flashpoint above 80.degree. C., and essentially liberate no alcohols by hydrolysis on dilution with water are obtainable by mixing water-soluble aminoalkylalkoxysilanes with alkyltrialkoxysilanes and/or dialkyldialkoxysilanes and/or mixtures of alkyltrialkoxysilanes and dialkyldialkoxysilanes which are not water-soluble, adding water to the mixture, adjusting the pH of the reaction mixture to a value of between 1 and 8 and removing any alcohol already present and/or formed during the reaction. Such compositions are especially useful for hydrophobicizing the surface of building materials such as brick, concrete, lime sand brick, and mortar.

Abstract: A binder composition for storable zinc dust paints contains a mixture of silicic acid esters, solvents, curing agents, an antideposition agent, and a dearomatized aliphatic hydrocarbon mixture with an average molecular weight of 133. The binder composition has a flash point distinctly higher than 21.degree. C.

Abstract: A binder composition for zinc dust paints contains silicic acid esters, solvents, curing agents, an anti-settling agent and n-butyl acetate. The composition has a flash point above 21.degree. C.

Abstract: The invention relates to polycrystalline, sintered abrasive granules based on .alpha.-Al.sub.2 O.sub.3 with a density of >98% of the theoretical density of corundum, a Vickers hardness of 21 GPa and greater and a crystallite size of 0.05 to 1.3 micron, as well as abrasives made from these abrasive granules and the use of these abrasive granules for the production of ceramic, refractory products.The polycrystalline, sintered abrasive granules based on .alpha.-Al.sub.2 O.sub.3 are produced by .alpha.-Al.sub.2 O.sub.3 crystal nuclei being added to a boehmite dispersion, the mixture of the boehmite dispersion and the crystal nuclei being acidified and gelled and the gel being dried, crushed, and sintered. In doing so, 0.5 to 35% by weight of .alpha.-Al.sub.2 O.sub.3 crystal nuclei, relative to the sintered abrasive granules, is added and the mixture of the boehmite dispersion and of the crystal nuclei is refluxed, while the pH of the mixture is kept in a range of 2.5 to 3.5 by adding acid.