Abstract: The invention relates to a process for the preparation of a polymerization mixture suitable as a dispersant and comprising a copolymer. In the process, a vinyloxyalkylpolyether derivative is reacted with an acid monomer derivative with formation of the copolymer in the presence of a free radical polymerization initiator by free radical polymerization, the free radical polymerization taking place in a medium which contains less than 25% by weight of water and in totality more than 60% by weight of copolymer, vinyloxyalkylpolyether derivative and acid monomer derivative.

Abstract: The invention concerns a process for the preparation of a hardening accelerator composition by reaction of a water-soluble calcium compound with a water-soluble silicate compound and a process for the preparation of a hardening accelerator composition by reaction of a calcium compound with a silicon dioxide containing component under alkaline conditions, in both cases the reaction of the water-soluble calcium compound with the water-soluble silicate compound being carried out in the presence of an aqueous solution which contains a water-soluble comb polymer suitable as a plasticizer for hydraulic binders. The invention concerns also a composition of calcium silicate hydrate and comb polymer, its use as hardening accelerator and for the reduction of the permeability of hardened compositions.

Abstract: The invention relates to a process for the preparation of copolymer in a continuous mode of operation in a polymerization apparatus, comprising a polymerization reactor having feed lines and an outflow, free radical polymerization initiator, an acid monomer and polyether macromonomer being passed as monomeric starting materials into the polymerization reactor through the feed lines, initiator, monomeric starting materials and copolymer-containing reaction composition thermostated at ?20 to +120° C.

Abstract: A valve comprising a drive part having a valve block with at least one outlet opening; a valve part having a tappet that can be moved by a drive, wherein the tappet opens or closes the outlet opening depending on its position; and a spring that is disposed between the valve block and the tappet.

Abstract: A process for the preparation of a copolymer in a semicontinuous mode of operation in a polymerization apparatus containing a polymerization reactor connected to a metering device, in each case acid monomer being initially introduced into the metering device and polyether macromonomer and water into the polymerization reactor, acid monomer being metered from the metering device into the polymerization reactor, the metering of the acid monomer into the polymerization reactor being effected in such a way that first a polymerization pH is established in the aqueous medium and then, until the conversion of 70 mol % of the polyether macromonomer initially introduced into the polymerization reactor, acid monomer is passed into the polymerization reactor in an amount per unit time such that the pH in the aqueous medium deviates by not more than ±0.3 from the initially established polymerization pH.

Abstract: A process for the preparation of a copolymer in semicontinuous operation in a polymerization apparatus, comprising a polymerization reactor connected to a metering device, acid monomer being initially taken in the metering device and polyether macromonomer, acid monomer and water in the polymerization reactor, acid monomer being metered from the metering device into the polymerization reactor, the metering of the acid monomer being effected with the proviso that at least 70 mol % of the acid monomer metered in altogether are metered in the course of 5 to 19 minutes at a metering rate that is constant or varies to a limited extent.

Abstract: The water retention agents according to the invention are outstandingly suitable as additives in construction chemistry systems and in the development, exploitation and completion of underground mineral oil and natural gas deposits and in deep wells, their effect being particularly advantageous at increased temperatures and because of their lack of influence on the rheological properties of the well slurries.

Abstract: The invention relates to a copolymer which is suitable as a superplasticizer for hydraulic binders and comprises 5 to 55 mol % of an isoprenol polyether derivative structural unit, 2 to 90 mol % of an acrylic acid derivative structural unit and 2 to 90 mol % of a hydroxyalkyl acrylate structural unit.

Abstract: The invention relates to a process for the preparation of polymers by free radical polymerization of monomers in the presence of water, electrochemically produced free radicals being used for initiating the free radical polymerization.

Abstract: The invention relates to a process for the preparation of an aqueous solution comprising 30 to 95% by weight of water and 5 to 70% by weight of a copolymer dissolved in the water by free radical solution polymerizations of an isoprenol polyether derivative with an acrylic acid derivative, so that the copolymer has 20 to 45 mol % of an isoprenol polyether derivative structural unit and 55 to 80 mol % of an acrylic acid derivative structural unit. The aqueous solution is suitable as a superplasticizer for hydraulic binders.

Abstract: Statistic comb polymers obtainable by the radical copolymerization of a vinylic poly(alkylenoxide) compound (A) with an ethylenically unsaturated monomer compound (B) according to the catalytic chain transfer method (CCT). The comb polymers are extremely suitable for hydraulic binder suspensions based on cement, lime, gypsum and anhydrite as they have, for the same dosage, an improved water reducing power over conventional flow agents. The corresponding building material mixtures are characterized by a substantially reduced stickiness and plastic viscosity once said comb polymers are added, which dramatically improves the plasticity of very cement-rich building material mixtures, such as concretes. The building material mixtures using the inventive flow agents have a considerably increased slump flow and an increased shear-thinning behavior as compared to conventional concretes without the tendency to segregate.

Abstract: The invention concerns a process for the preparation of a hardening accelerator composition by reaction of a water-soluble calcium compound with a water-soluble silicate compound and by reaction of a calcium compound with a silicon dioxide containing component under alkaline conditions, in both cases the reaction being carried out in the presence of an aqueous solution of a water-soluble polymer, which contains sulphonic acid and/or sulphonate groups and aromatic groups. The invention concerns also the reaction product of said processes and its use as hardening accelerator for building materials.

Abstract: The invention concerns a process for the preparation of a hardening accelerator composition by reaction of a water-soluble calcium compound with a water-soluble silicate compound and by reaction of a calcium compound with a silicon dioxide containing component under alkaline conditions, in both cases the reaction being carried out in the presence of a polycondensate containing at least one structural unit consisting of an aromatic or heteroaromatic moiety bearing a polyether side chain and at least one structural unit consisting of an aromatic or heteroaromatic moiety bearing at least one phosphoric acid ester group and/or its salt. The invention concerns a composition of calcium silicate hydrate and the polycondensate, its use as hardening accelerator and for the reduction of the permeability of hardened compositions.

Abstract: The use of polymeric microparticles having a cavity in hydraulically setting building material mixtures is described, from 1 to 100% by volume of the cavity of these microparticles being filled with water. In this way, remarkable concrete resistance to the freezing and thawing cycle is achieved, these microparticles providing improved protection for the concrete from the effects of the freezing and thawing cycle, even at a diameter of from 0.1 to 1 ?m and in doses which are 1 to 2 orders of magnitude lower than those described in the prior art. Moreover, the compressive strength of the correspondingly hardened concrete is substantially improved, which was likewise not foreseeable.

Abstract: A fluidizing admixture for use with sprayable cementitious compostions, the admixture consists of 2-phosphonobutane-1,2,4-tricarboxylic acid and at least one selected polymer derived from ethylenically-unsaturated mono- or dicarboxylic acids. Citric acid may optionally be present. The admixture has good fluidizing properties and outstanding shelf-life.

Abstract: The present invention provides a composition comprising a pesticide having a solubility in water of at most 10 g/l and a polycarboxylate ether based on a) component groups of the formula Ia and/or Ib and/or Ic as defined below, and b) component groups of the general formula Il as defined below. The present invention further provides a process for producing the composition. The invention further relates to a method of controlling phytopathogenic fungi and/or unwanted plant growth and/or unwanted insect or mite infestation and/or of regulating the growth of plants, wherein the composition is allowed to act on the particular pests, the surroundings thereof or the plants to be protected from the particular pest, the soil and/or on unwanted plants and/or the crop plants and/or the surroundings thereof. The invention also relates to seed comprising the composition.

Abstract: The invention relates to a polymer composition containing 5 to 95% by weight of a copolymer H and 2 to 60% by weight of a copolymer K, the copolymers H and K each having polyether macromonomer structural units and acid monomer structural units, which are present in the copolymers H and K in each case in a molar ratio of 1:20 to 1:1, and at least 20 mol % of all structural units of the copolymer H and at least 25 mol % of all structural units of the copolymer K being present in each case in the form of acid monomer structural units, the polyether macromonomer structural units of the copolymer H having side chains containing in each case at least 5 ether oxygen atoms, the number of ether oxygen atoms per side chain of the polyether macromonomer structural units of the copolymer H varying in such a way that the corresponding frequency distribution diagram, in which the number of ether oxygen atoms per side chain of a polyether macromonomer structural unit is plotted along the abscissa and the associated frequenc

Abstract: The invention relates to a process for the preparation of a copolymer in semicontinuous operation in a polymerization apparatus, comprising a polymerization reactor connected to a metering device, in each case acid monomer being initially taken in the metering device and polyether macromonomer, acid monomer and water in the polymerization reactor, acid monomer being metered from the metering device into the polymerization reactor, free radical polymerization initiator being passed into the polymerization reactor before and/or during the metering of the acid monomer into the polymerization reactor so that an aqueous medium in which acid monomer and polyether macromonomer are reacted with formation of the copolymer by free radical polymerization forms in the polymerization reactor, the molar ratio of acid monomer used altogether to polyether macromonomer used altogether being 20:1 to 1:1, the molar ratio of acid monomer initially taken in the polymerization reactor to the acid monomer metered into the polymeriz

Abstract: The invention relates to a process for the preparation of a polymerization mixture suitable as a dispersant and comprising a copolymer. In the process, a vinyloxyalkylpolyether derivative is reacted with an acid monomer derivative with formation of the copolymer in the presence of a free radical polymerization initiator by free radical polymerization, the free radical polymerization taking place in a medium which contains less than 25% by weight of water and in totality more than 60% by weight of copolymer, vinyloxyalkylpolyether derivative and acid monomer derivative.

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.