Abstract: Continuous processes for preparing polycarbonates having a weight average molecular weight Mw, of 15,000 to 200,000 g/mol, the processes comprising reacting a dihydroxydiarylalkane and phosgene in the presence of a catalyst in a phase boundary process comprising: continuously dispersing in a disperser an organic phase comprising at least a portion of the phosgene and a solvent suitable for the polycarbonate and an aqueous phase comprising the dihydroxydiarylalkane, water and an alkali solution present in an amount of 1.5 to 2.5 moles per mole of the dihydroxydiarylalkane, to form a mixture; reacting the mixture in a first reactor with a residence time of less than 0.5 seconds; further reacting the mixture in a second reactor with addition of further alkali solution and, optionally, a chain terminator; and effecting further condensation in a third reactor with addition of further alkali solution and, optionally, a chain terminator, in the presence of the catalyst.

Abstract: The invention relates to a device (1) for the treatment of substance mixtures conveyed under high pressure, with a casing (3) surrounding a high-pressure space (2), with at least one sealing means (12) in order to seal off the high-pressure space (2) with respect to the surroundings, and with an inlet (4) and an outlet (5) in order respectively to supply the substance mixture to be treated to the high-pressure space (2) and to discharge it from the high-pressure space (2). The high-pressure space (2) is closed, via at least one cover for mounting and demounting, by a processing module arranged in the high-pressure space (2), the cover having a central fastening means (6) which can be locked, oriented coaxially with respect to the casing (3).

Abstract: Continuous processes for preparing polycarbonates having a weight average molecular weight MW, of 15,000 to 200,000 g/mol, the processes comprising reacting a dihydroxydiarylalkane and phosgene in the presence of a catalyst in a phase boundary process comprising: continuously dispersing in a disperser an organic phase comprising at least a portion of the phosgene and a solvent suitable for the polycarbonate and an aqueous phase comprising the dihydroxydiarylalkane, water and an alkali solution present in an amount of 1.5 to 2.5 moles per mole of the dihydroxydiarylalkane, to form a mixture; reacting the mixture in a first reactor with a residence time of less than 0.5 seconds; further reacting the mixture in a second reactor with addition of further alkali solution and, optionally, a chain terminator; and effecting further condensation in a third reactor with addition of further alkali solution and, optionally, a chain terminator, in the presence of the catalyst.

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: A process for the preparation of polymeric condensates, wherein the reaction mixture is fed at least once during the condensation reaction through a zone of high energy density which has an energy density of at least 105 J/m3.

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: 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 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: A process for the preparation of polymeric condensates, wherein the reaction mixture is fed at least once during the condensation reaction through a zone of high energy density which has an energy density of at least 105 J/m3.

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 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.