Abstract: Dispersion which is free of binders and which contains silica and at least one superplasticizer, the silica being a precipitated silica having a surface area greater than 50 m2/g, the aggregates and/or agglomerates in the dispersion having a median diameter of less than 1 ?m and the proportion of silica being from 5 to 50% by weight, based on the total amount of the dispersion, and a process for the preparation thereof and the use thereof as a concrete admixture in cement-containing preparations.

Abstract: The invention relates to a process for the preparation of a copolymer by free radical mass polymerization of a maleic acid monoester derivative with vinyl ester in the presence of an acid having a pKa of less than 1.8. The copolymer is suitable as a dispersant for hydraulic binders.

Abstract: Pulverulent polycondensation products are described, consisting of a) 5 to 95% by weight of a polycondensation product based on an aromatic or heteroaromatic compound (A) having 5 to 10 C atoms or heteroatoms having at least one oxyethylene or oxypropylene radical and one aldehyde (C) selected from the group consisting of formaldehyde, glyoxylic acid and benzaldehyde or mixtures thereof, and b) 5 to 95% by weight of a finely divided mineral carrier material having a specific surface area of 0.5 to 500 m2/g (according to BET as specified in DIN 66 131). The pulverulent polycondensation products according to the invention are outstandingly suitable in construction material mixtures in an amount of from 0.1 to 5% by weight, based on the weight of the construction material. The pulverulent polycondensation products have a number of advantages here, such as, for example, excellent storage stability, good liquefying action at low dosage and industrially simple production.

Abstract: Disclosed is a polycondensation product that is a reaction product of A) an aromatic or heteroaromatic compound containing 5 to 10 C atoms or heteroatoms and is provided with an average of 1 to 300 oxyethylene groups and/or oxypropylene groups per molecule which are linked to the aromatic or heteroaromatic compound via an O atom or N atoms, and B) an aromatic compound and C) an aldehyde selected among the group of formaldehyde, glyoxylic acid, and benzaldehyde or mixtures thereof. Surprisingly, the inventive polycondensation product causes very good liquefaction of hydraulic binding agents, eg. Cement, resulting in substantially improved liquefaction of the construction material at a lower dose while pourability can be maintained over a longer period of time as opposed to naphthalene sulfonates or melamine sulfonates.

Abstract: The invention relates to a process for the preparation of a copolymer by free radical mass polymerization of a maleic acid monoester derivative with vinyl ester in the presence of an acid having a pKa of less than 1.8. The copolymer is suitable as a dispersant for hydraulic binders.

Abstract: Dispersion which is free of binders and which contains silica and at least one superplasticizer, the silica being a precipitated silica having a surface area greater than 50 m2/g, the aggregates and/or agglomerates in the dispersion having a median diameter of less than 1 ?m and the proportion of silica being from 5 to 50% by weight, based on the total amount of the dispersion, and a process for the preparation thereof and the use thereof as a concrete admixture in cement-containing preparations.

Abstract: A process for the preparation of products of high early strength comprising hydraulic binders, in which a hydraulic binder, water and 0.1 to 5% by weight, based on the hydraulic binder, of a finely divided titanium dioxide are mixed with agitation and in any desired sequence.

Abstract: Pulverulent polycondensation products are described, consisting of a) 5 to 95% by weight of a polycondensation product based on an aromatic or heteroaromatic compound (A) having 5 to 10 C atoms or heteroatoms having at least one oxyethylene or oxypropylene radical and one aldehyde (C) selected from the group consisting of formaldehyde, glyoxylic acid and benzaldehyde or mixtures thereof, and b) 5 to 95% by weight of a finely divided mineral carrier material having a specific surface area of 0.5 to 500 m2/g (according to BET as specified in DIN 66 131). The pulverulent polycondensation products according to the invention are outstandingly suitable in construction material mixtures in an amount of from 0.1 to 5% by weight, based on the weight of the construction material. The pulverulent polycondensation products have a number of advantages here, such as, for example, excellent storage stability, good liquefying action at low dosage and industrially simple production.

Abstract: Disclosed is a polycondensation product comprising A) an aromatic or heteroaromatic compound containing 5 to 10 C atoms or heteroatoms, said compound being provided with an average of 1 to 300 oxyethylene groups and/or oxypropylene groups per molecule which are linked to the aromatic or heteroaromatic compound via an O atom or N atom, and optionally B) an aromatic compound selected among the group comprising phenols, phenol ether, naphthols, naphthol ether, anilines, furfuryl alcohols, and/or an aminoplast former selected among the group comprising melamine (derivatives), urea (derivatives), and carboxylic acid amides, and C) an aldehyde selected among the group comprising formaldehyde, glyoxylic acid, and benzaldehyde or mixtures thereof, the benzaldehyde optionally containing acid groups in the form of COOMa, SO3Ma, and PO3Ma, wherein M=H, akali metal or alkaline earth metal, ammonium, or organic amine radicals and a=½, 1, or 2.