Abstract: A process for the continuous production of an aqueous polyurethane dispersion based on at least one aliphatic and/or aromatic polyisocyanate is described, which is characterised by the following steps: a) production of an aqueous pre-emulsion by mixing a polyurethane prepolymer containing hydrophilic and/or potentially hydrophilic groups with water in a mixing nozzle, wherein the polyurethane prepolymer is injected into the water; b) formation of an emulsion by homogenization of the pre-emulsion from step a) in a multi-step homogenizing nozzle. Paint films containing the aqueous polyurethane dispersion produced by the process can be used to coat substrates.

Abstract: The invention describes a homogenising nozzle 100 comprising a casing 10, a piston 11 arranged displaceably along the longitudinal axis of the casing 10, a first inlet 14 for a first component, a second inlet 15 for a second component and an outlet 16 for a homogenised mixture of the first and second components, wherein the first inlet 14 and the outlet 16 are arranged along the longitudinal axis of the casing 10 in such a manner that, by displacing the piston 11, the free cross-section of the first inlet 14 and the free cross-section of the outlet 16 may be varied. A process is furthermore described for the production of an aqueous two-component polyurethane coating emulsion by mixing at least one aqueous binder dispersion comprising isocyanate-reactive groups and a polyisocyanate using the described homogenising nozzle.

Abstract: Novel pulverulent active substance formulations composed of at least one active substance which is solid at room temperature, at least one dispersant, polyvinyl alcohol and if desired, additives, the individual active substance particles being enveloped by a coat of polyvinyl alcohol, being present in the amorphous state, and having diameter in the nanometer range, a process for producing the novel formulations and their use for the application of the active substance they comprise and also a device for carrying out the production process.

Abstract: The invention relates to a process for the production of aqueous two-component polyurethane lacquer emulsions, with variable throughput, and to the use thereof as high-quality lacquers and coatings.

Abstract: The invention relates to a dispersing device wherein the dispersed material has a variable throughput comprising a jet disperser which comprises at least one inlet for the materials to be dispersed, a chamber with a multiciplicity of openings arranged in rows along the chamber wall, which lead into an outlet chamber, and an outlet for the finally dispersed material, wherein the chamber comprises a displaceably mounted piston which, depending on its position within the chamber, partially or completely shuts off a specific number of the openings for the passage of the flow os dispersed material.

Abstract: A process for the continuous production of an aqueous polyurethane dispersion based on at least one aliphatic and/or aromatic polyisocyanate is described, which is characterised by the following steps: a) production of an aqueous pre-emulsion by mixing a polyurethane prepolymer containing hydrophilic and/or potentially hydrophilic groups with water in a mixing nozzle, wherein the polyurethane prepolymer is injected into the water; b) formation of an emulsion by homogenisation of the pre-emulsion from step a) in a multi-step homogenising nozzle. Paint films containing the aqueous polyurethane dispersion produced by the process can be used to coat substrates.

Abstract: Finely divided polysacharide derivatives are described. The finely divided polysacharide derivatives are prepared by a process comprising: a) forming an aqueous composition comprising a polysaccharide derivative and water, in which the polysaccharide derivative is soaked or dissolved; b) converting the polysaccharide derivative of the aqueous composition into finely divided solid particles by, (i) contacting the aqueous composition with superheated water vapor in a dryer-pulverizer; or (ii) causing the polysaccharide derivative of the aqueous composition to flocculate; and c) optionally drying the finely divided solid particles of step b). The primary structures of the polysaccharide starting material are largely removed, and the product has a shape factor of less than 5 and greater than or equal to 1.

Abstract: The invention provides an improved process for the preparation of double metal cyanide (DMC) catalysts for the preparation of polyether polyols by polyaddition of alkylene oxides on to starter compounds containing active hydrogen atoms, in which aqueous solutions of a metal salt and a metal cyanide salt are first reacted in the presence of an organic complexing ligand and optionally one or more further complex-forming components to form a DMC catalyst dispersion, this dispersion is then filtered, the filter cake is subsequently washed with one or more aqueous or non-aqueous solutions of the organic complexing ligand and optionally one or more further complex-forming components by a filter cake washing and the washed filter cake is finally dried, after an optional pressing out or mechanical removal of moisture.

Abstract: The invention provides an improved process for the preparation of double metal cyanide (DMC) catalysts for the preparation of polyether polyols by polyaddition of alkylene oxides on to starter compounds containing active hydrogen atoms, in which aqueous solutions of a metal salt and a metal cyanide salt are first reacted in the presence of an organic complexing ligand and optionally one or more further complex-forming components to form a DMC catalyst dispersion, this dispersion is then filtered, the filter cake is subsequently washed with one or more aqueous or non-aqueous solutions of the organic complexing ligand and optionally one or more further complex-forming components by a filter cake washing and the washed filter cake is finally dried, after an optional pressing out or mechanical removal of moisture.

Abstract: The invention relates to an apparatus for the production of a two-component coating mixture, in particular for the production of a an aqueous two-component polyurethane coating emulsion from an aqueous binder dispersion comprising isocyanate-reactive hydrogen atoms and a polyisocyanate, with a mixer for the production of the two-component coating mixture by mixing a first coating component and a second coating component and with a homogeniser for homogenisation of the two-component coating mixture, the homogeniser being downstream from the mixer. It is proposed that, in the outlet zone of the homogeniser, a return line branches off, which opens into the inlet zone of the homogeniser, in order to recirculate a portion of the two-component coating mixture homogenised by the homogeniser for rehomogenisation. The invention furthermore comprises a corresponding process and a substrate which is coated with a coating produced in corresponding manner.

Abstract: The invention relates to an improved method of producing double-metal cyanide (DMC) catalysts for the production of polyether polyols by polyaddition of alkylene oxides to starter compounds containing active hydrogen atoms, in which the DMC catalyst dispersion is produced using a mixing nozzle, preferably a jet disperser. The DMC catalysts produced in this way have an increased activity in polyether polyol production, reduced particle size and narrower particle size distribution.

Abstract: The present invention relates to a process for the production of polyether polyols by polyaddition of alkylene oxides onto starter compounds containing active hydrogen atoms conducted in the presence of a double-metal cyanide catalyst wherein a reaction mixture is guided at least once through a zone which has an energy density of at least 105 J/m3 and wherein the residence time of the reaction mixture in this zone is at least 10−6 seconds per pass.

Abstract: Pulverulent active substance formulations composed of

Abstract: The present invention relates to a process for the production of a polyether polyol by polyaddition of an alkylene oxide onto a starter compound containing active hydrogen atoms conducted in the presence of a double metal cyanide catalyst comprising conducting a reaction mixture at least once through a zone which has an energy density of at least 5×106 J/m3, wherein the dwell time of the reaction mixture in this zone is at least 10−6 seconds per pass.

Abstract: The invention provides an improved process for the preparation of double metal cyanide (DMC) catalysts for the preparation of polyether polyols by polyaddition of alkylene oxides on to starter compounds containing active hydrogen atoms, in which aqueous solutions of a metal salt and a metal cyanide salt are first reacted in the presence of an organic complexing ligand and optionally one or more further complex-forming components to form a DMC catalyst dispersion, this dispersion is then filtered, the filter cake is subsequently washed with one or more aqueous or non-aqueous solutions of the organic complexing ligand and optionally one or more further complex-forming components by a filter cake washing and the washed filter cake is finally dried, after an optional pressing out or mechanical removal of moisture.

Abstract: The present invention relates to a process for the production of a polyether polyol by polyaddition of an alkylene oxide onto a starter compound containing active hydrogen atoms conducted in the presence of a double metal cyanide catalyst comprising conducting a reaction mixture at least once through a zone which has an energy density of at least 5×106 J/m3, wherein the dwell time of the reaction mixture in this zone is at least 10−6 seconds per pass.

Abstract: The present invention relates to a process for the production of polyether polyols by polyaddition of alkylene oxides onto starter compounds containing active hydrogen atoms conducted in the presence of a double-metal cyanide catalyst wherein a reaction mixture is guided at least once through a zone which has an energy density of at least 105 J/m3 and wherein the residence time of the reaction mixture in this zone is at least 10−6 seconds per pass.

Abstract: Finely divided polysacharide derivatives are described. The finely divided polysacharide derivatives are prepared by a process comprising: a) forming an aqueous composition comprising a polysaccharide derivative and water, in which the polysaccharide derivative is soaked or dissolved; b) converting the polysaccharide derivative of the aqueous composition into finely divided solid particles by, (i) contacting the aqueous composition with superheated water vapor in a dryer-pulverizer; or (ii) causing the polysaccharide derivative of the aqueous composition to flocculate; and c) optionally drying the finely divided solid particles of step b). The primary structures of the polysaccharide starting material are largely removed, and the product has a shape factor of less than 5 and greater than or equal to 1.

Abstract: The invention relates to a coating compound for fibers and to a process for the production thereof The invention relates in particular to a preparation agent for elastanes, based on a dispersion of fatty-acid metal salts and an agglomeration inhibitor in polyorganosiloxanes and mineral oils. The preparations are produced by a precipitation process from which fined-particle and sedimentation-stable dispersions with a narrow particle size distribution are obtained which are free from agglomerates.

Abstract: Process for preparing non-aqueous dispersions, wherein a liquid prepolymer is emulsified in a non-aqueous liquid, the droplet size of the emulsion is adjusted to 0.1 to 30 &mgr;m and the droplet size distribution U90 is adjusted to less than 2 by means of a jet disperser, and the droplets are cured by a chemical reaction.