CONTINUOUS PROCESS FOR REACTIONS WITH FINE-PIECE ALKALIMETAL DISPERSIONS

Description

[0001] The present invention relates to a continuous process in which fine alkali metal dispersions in organic solvents are generated on a spinning disc reactor (SDR) and used for the coupling of organic esters and halides as well as organohalosilanes.

[0002] Alkali metals, and among them especially sodium, have long been established as reagents in organic chemistry, for example for the preparation of alcoholates, for the glycidyl ester condensation according to Darzens, for the Birch reduction for the conversion of aromatic into aliphatic compounds or for the acyloin condensation of esters to α-hydroxycarbonyl compounds (K. Rühlmann Synthesis (1971), (1971(5), 236-253). The latter reaction in particular is of importance in organic chemistry for the intramolecular cyclization of dicarboxylic acid esters to medium and large ring systems.

[0003] Another major application area for elemental alkali metals is the Wurtz coupling, or Wurtz synthesis, discovered in 1854 by the French chemist Adolphe Wurtz. Initially, it was primarily used for the synthesis of (cyclo)alkanes starting from haloalkanes. Cycloalkanes with a ring size of three to six carbon atoms are accessible by means of the Wurtz synthesis. The Wurtz coupling is also the main route for the preparation of σ-π-conjugated silicon polymers via the polycondensation of halosilanes in aprotic organic solvents (RD Miller, J. Michl Chemical Reviews (1989), 89 (6), 1359-1410).

[0004] The reactions mentioned are carried out according to the current state of the art in a semibatch process (described, inter alia, in patents EP 0 123 934 B1, EP 0 632 086 B1, EP 0 382 651 A1, EP 1 769 019 A1, DE 10 2012 223 260 A1, EP 2 872 547 A1, EP 0 230 499 B1, JP 3087921 B2, JP 2736916 B2, CN 103508869 B, US 4324901 A, US 4276424 A). For this purpose, a suspension of an alkali metal (for example, sodium) is placed in a reaction vessel. The substances to be coupled (haloalkanes, halosilanes, or di- / esters) are added to this under strictly controlled conditions. However, this process entails numerous safety risks and process engineering problems. Firstly, handling the liquid alkali metals, as well as some of the reactants such as the highly reactive chlorosilanes, is very complex on a production scale. Therefore, moisture must be completely excluded at all costs.Furthermore, since the reaction is highly exothermic, the reproducibility of the product properties is affected even by small fluctuations within different batches. Even on a laboratory scale, for example, poor reproducibility of the results of a Wurtz coupling reaction for the production of polysilanes has been observed.

[0005] Since reactions with alkali metal dispersions are interfacial reactions, a dispersion as fine as possible and thus a high particle surface area are advantageous for rapid and complete reactions. However, for a semibatch process, this is difficult to precisely adjust in production, leading to deviations in the process. Precise dosing of the reactants (e.g., halogen compounds, esters) is also essential for precise reaction control, since different dosing rates can lead to deviations in the temperature profile. For the reasons mentioned above, it is easy to understand that these factors also significantly complicate the upscaling of the semibatch process and the associated large-scale use of the reaction.

[0006] For the reaction of alkali metals with alcohols above the melting point of the metals, a microreactor with a static mixer and heat exchanger with channel dimensions of around 500 µm was used in EP 1162187 B1.

[0007] The use of SDRs is state of the art for the epoxidation of substituted cyclohexanones EP 1 20 6460 B1, reactions of carboxylic acids and esters WO 2002 / 018328 A1, the production of nanoparticles US 8,870,998 B2, for the hydrogenation of nitrile rubber in solution EP 1 862 477 B1, for heterogeneously catalyzed reactions EP 1 152 823 B2, and for carrying out radical emulsion polymerizations US 7,683,142 B2.

[0008] In addition, applications for the production of titanium dioxide particles (S. Mohammadi; A. Harvey; KVK Boodhoo Chemical Engineering Journal (2014), 258, 171-184), for the cationic polymerization of styrene using an immobilized catalyst (KVK Boodhoo; WAE Dunk; M. Vicevic; RJ Jachuck; V. Sage; DJ Macquarrie; JH Clark Journal of Applied Polymer Science (2006), 101(1), 8-19), for the photopolymerization of n-Butyl acrylate (KVK Boodhoo; WAE Dunk; RJ Jachuck ACS Symposium Series (2003), 847 (Photoinitiated Polymerization), 437-450), as well as for the production of mayonnaise (M. Akhtar; BS Murray; S. Dowu Food Hydrocolloids (2014), 42(S), 223-228), apple juice concentrate (M. Akhtar; P. Chan; N. Safriani; B. Murray; G. Clayton Journal of Food Processing & Technology (2011), 2(2), 1000108) and ice cream base emulsions (M. Akhtar; I. ​​Blakemore; G. Clayton; S. Knapper International Journal of Food Science and Technology (2009), 44(6), 1139-1145). Furthermore, the company Flowid has implemented a lithium-halogen exchange process at room temperature with a product flow of 100 kg / h of raw material and 20 kg / h of product for Biogen (http: / / www.flowid.nl / successful-scale-up-of-butyl-lithium-usingthe-spinpro / 08.08.2015). Furthermore, numerous examples of recrystallization and particle synthesis are described in the literature.The advantages of SDR technology for these multiphase systems have been extensively discussed and illustrated in the literature (K. Boodhoo & A. Harvey Process Intensification for Green Chemistry: Engineering Solutions for Sustainable Chemical Processing (2013), Chapter 3, John Whiley & Sons Ltd, pp 59-90), SD Pask, O. Nuyken, Z. Cai Polymer Chemistry (2012), 3, 2698), P. Oxley, C. Brechtelsbauer, F. Ricard, N. Lewis, C. Ramshaw Industrial & Engineering Chemistry Research (2000), 39(7), 2175-2182).

[0009] DE 696 00 862 T2 discloses a safe, efficient process for the production of sodium C4-C8 alkoxide using a less than stoichiometric amount of a C4-C8 alcohol and the possibility of continuous recycling of the unreacted sodium metal.

[0010] US 2,631,175 A describes a process for producing polybutadiene. In particular, a continuous process is disclosed in which a finely divided sodium dispersion is used as a catalyst.

[0011] WO 2006 / 084878 A1 discloses processes for preparing tertiary phosphines by reacting a compound of the general formula (I) A,BP-L1, in which A is R1 or L2, B is R2 or L3, the radicals R1 and R2 independently of one another are an organic radical each having 1 to 30 carbon atoms, where the radicals R1 and R2 may also be bonded to one another; and the leaving groups L1 to L3 independently of one another are halogen, alkyloxy having 1 to 10 carbon atoms or aryloxy having 6 to 10 carbon atoms, (a) with an alkali metal in an organic aprotic solvent and (b) a compound of the general formula (II) L4-R3 in which the radical R3 is an organic radical each having 1 to 30 carbon atoms;and the leaving group L4 represents halogen, alkyloxy having 1 to 10 carbon atoms or aryloxy having 6 to 10 carbon atoms, in which the resulting reaction mixture is hydrolyzed with an aqueous base having a pH of >= 10 and the organic phase is separated from the aqueous phase.;

[0012] The present invention is based on the object of providing a continuous process for carrying out chemical reactions with liquid fine-particle alkali metal dispersions in inert solvents, which is not limited by the described problems of the semi-batch procedure.

[0013] Surprisingly, it has been found that the above-mentioned object is achieved in a first embodiment by the use of a device for carrying out continuous chemical reactions for converting finely divided alkali metal dispersions in inert solvents, or according to the invention by the use of a rotary disk reactor for carrying out continuous chemical processes using liquid finely divided dispersions of alkali metals, alkali metal mixtures and / or alkali metal alloys in inert solvents.

[0014] Well-known systems in continuous production technology are plug flow reactors (PFRs), continuously stirred tank reactors (CSTRs) and their cascades, as well as microreaction technology (MRT). For the normally highly exothermic interfacial reactions on dispersed alkali metals, highly efficient mixing is essential to ensure the highest possible mass flow of reactants and products to or from the surface, as well as to quickly dissipate the resulting heat. This can be achieved, for example, with static mixers in flow tube or microreactors. These also exhibit an ideal residence time distribution. Good mixing is also possible in CSTRs; they have the additional advantage of being comparatively easy to clean, which prevents fouling or blocking in multiphase reactions (e.g.with two immiscible liquid components or solid reaction products) is a minor problem.

[0015] A preferred system of continuous production technology that has so far been little used is the rotary disk reactor ( English Spinning Disc Reactor (SDR).

[0016] According to the invention, the essential problems of a semi-batch process for conducting reactions with finely divided alkali metal dispersions can be eliminated by a continuous procedure: In a continuous reaction process, only small amounts of hazardous substances are combined per unit of time and, ideally, are mixed efficiently. If a highly exothermic reaction is handled, the resulting heat can be easily dissipated due to a high surface-to-volume ratio, resulting in a homogeneous temperature profile in the reaction mixture. All of this leads to a significant improvement in the safety aspect of such reactions, as well as to a significantly improved reproducibility of product quality in the steady state of such a continuous process.

[0017] The present invention is particularly applicable to the Wurtz coupling of halogen compounds and the acyloin condensation of esters. The liquid two-phase system present before the reaction, or the concentrated salt dispersion formed during the Wurtz coupling, does not lead to fouling or blockage in continuously operated SDRs due to the high shear forces in this dynamic system.

[0018] Fig. 1shows an exemplary flow diagram for the present invention: Reference numeral 1 stands for a metering container with liquid alkali metal or alkali metal mixture / alloy; Reference numeral 2 stands for a metering container of the reactant or a reactant mixture; Reference numeral 3 stands for a metering container of the solvent or a solvent mixture; Reference numeral 4 stands for a spinning disc reactor (SDR); Reference numeral 5 stands for an optional residence time unit (for example stirred tank, stirred tank cascade, heat exchanger); Reference numeral 6 stands for a collecting container for the product mixture; Reference numeral 7 stands for a collecting container for the by-product mixture.

[0019] Based on the above examples, the rotating disk reactor was developed as a suitable technology for conducting reactions with liquid alkali metal dispersions in inert organic solvents, particularly the Wurtz coupling of halogen compounds and acyloin condensation, with the formation of solid precipitates. This reactor type was developed for process intensification to particularly optimize heat transfer (heating, cooling, heat exchange) and mass transfer processes (mixing, dispersing). The technology is based on one or more disks mounted horizontally on a rotating axis driven by an electric motor. A liquid applied to the surface of this disk is propelled to the edge of the disk or beyond by the centrifugal force acting on it.High shear forces act in the thin film formed, resulting in excellent heat and mass transfer rates. This allows the heat generated in highly exothermic reactions to be quickly dissipated, and mass transport can be maximized in diffusion-limited processes. The high shear forces introduced into the flowing liquid film also lead to strong turbulence, which offers decisive advantages, especially for reactions in multiphase systems: The high shear forces cause the dispersed phase to be very finely distributed and the interface between two immiscible phases to be maximized. This optimizes mass transport toward and away from the interface. Furthermore, the rotational movement is strong enough to eject solid deposits from the disk surface, triggering a type of self-cleaning mechanism and reducing fouling or blocking through the formation of precipitate.

[0020] Typically, the use described in this invention takes place in a liquid medium consisting of an inert solvent or solvent mixture and the reactants dissolved therein (for example, haloalkanes, halosilanes, esters). In general, to achieve a high reaction rate, the alkali metal or alkali metal mixture or alloy used must be in a molten state in order to finely disperse it in the reaction medium. The alkali metal or alkali metal mixture or alloy, the reactants, and solvent are each metered separately into the reactor. The reaction of the alkali metal or alkali metal mixture or alloy with the reactants produces an alkali metal salt that is insoluble in the reaction mixture, as well as, depending on the type of reaction, a coupling product that is soluble or insoluble in the liquid medium.It is therefore a continuously carried out multiphase reaction in which the reactive phases are liquid and one or more reaction products precipitate as a solid.

[0021] All reaction steps typically take place under an inert gas atmosphere to prevent side reactions caused by oxygen or atmospheric humidity, in particular the formation of hydrogen and hydrogen chloride.

[0022] In principle, all alkali metals, their mixtures, and / or alloys are suitable for producing the alkali metal dispersion. Alkali metals, or mixtures and / or alloys thereof, whose melting points are in the range between -20 and 190°C are preferred. Lithium, sodium, and potassium, as well as their mixtures and alloys, are particularly preferred, as they are readily available and melt within a temperature range that is easily manageable.

[0023] All technically common aprotic organic solvents in which the reactants (for example, halogen compounds of the elements of main group IV or organic esters) are soluble and which do not react with the alkali metal or the alkali metal mixture or alloy used can be used as inert solvents. Hydrocarbons such as benzene, toluene, xylene and aliphatic hydrocarbons, as well as ethers such as dioxane, anisole and THF are preferably used. The inert solvent can also be a mixture of the solvents mentioned, e.g. of a hydrocarbon and an ether, for example toluene and THF. Typically, the alkali metal salt formed in the reaction is insoluble in the solvent used and can be separated by filtration of the precipitate.

[0024] Various substances can be used as reactants: The process according to the invention can be used to react all substrates commonly used for Wurtz coupling, such as mono-, di-, tri-, and polyfunctional alkyl and aryl halides and mixtures thereof, as well as mono-, di-, tri-, and polyfunctional haloorganosilanes and mixtures thereof. Fluorine, chlorine, bromine, and iodine can be used as halogens in the halogen compounds; chlorine, bromine, and iodine are preferred, and chlorine and bromine are particularly preferred. The invention is particularly suitable for producing polysilanes and polycarbosilanes from halogenated organosilane building blocks that are not polysilanes. The halogenated organosilane building blocks are defined by having fewer than 5 silicon atoms, preferably a maximum of 3 silicon atoms, particularly preferably a maximum of 2 silicon atoms, and very particularly preferably only one silicon atom.

[0025] Monoesters, diesters, triesters, and polyesters are used for acyloin condensation. Monoesters and diesters are preferred. The described process is particularly suitable for the intramolecular cyclization of dicarboxylic acid esters to form medium and large ring systems.

[0026] In the present invention, the amount of solvent, alkali metal, and reactants must be selected such that the reaction medium remains fluid even after the formation of the solid alkali metal halides and any insoluble products, so that fouling and blockage of the SDR are minimized. Typically, 5 to 99 wt.% solvent, based on the total reaction mixture, is used, preferably 50 to 97 wt.%, with 70 to 95 wt.% solvent being particularly preferred.

[0027] According to the invention, the ratio of the alkali metals or their mixtures and / or alloys to the reactants used is selected so as to achieve the most complete conversion possible. When preparing low-molecular-weight coupling products, stoichiometric use is preferred. For the preparation of polymeric coupling products, an excess of the alkali metal over the halide is typically required, preferably an excess of up to 20 wt. %, more preferably an excess of up to 10 wt. %, most preferably an excess of up to 5 wt. %.

[0028] The process described in this invention can be carried out over a wide temperature range. The temperature range is limited by the fact that it is a multiphase process with two liquids, more precisely the molten alkali metal or the molten alkali metal mixture or alloy and the reaction medium consisting of solvent and reactants. The lower limit for the temperature range is therefore the melting temperature of the alkali metal or the alkali metal alloy / mixture. The upper limit results from the boiling range of the reaction mixture and the technical design of the SDR. The reaction is preferably carried out in a range between 50 and 200°C, particularly preferably between 100 and 115°C.

[0029] The rotation speed of the SDR turntable must be selected so that optimal dispersion of the liquid alkali metal or alkali metal mixture / alloy in the solvent is achieved.

[0030] A further advantage of the present invention is the high surface area to volume ratio of the reaction mixture and the efficient mixing thereof, which enables efficient removal of the heat generated in the exothermic reaction. This results in a short residence time of the reaction mixture in the SDR and thus a short overall process time while simultaneously reducing the hazard potential of the reaction. The resulting high space-time yield makes the described process economically highly interesting compared to established semi-batch processes. Typically, the residence time of the reaction mixture in the SDR is <10 min, particularly preferably <5 min. During this time, the majority of the exothermic energy of the reaction is released and dissipated. In order to maximize the conversion of the reactive groups, especially in the production of polymeric reaction products, a residence time unit can optionally be installed downstream.All suitable units known to the person skilled in the art are suitable, in particular a continuous stirred tank, a stirred tank cascade, a heat exchanger and thermostattable loop reactors.

[0031] Once the reaction has reached the desired degree of conversion, the reaction product can be separated from the reaction mixture and, if necessary, purified by any suitable method known to those skilled in the art. For example, if the product is soluble in the reaction medium, the solid alkali metal salt precipitate, along with any residual alkali metal, is first separated by filtration. The product is then obtained, for example, by fractional distillation or by distilling off the solvent. If the product is insoluble in the reaction medium, it can be separated by filtration together with the solid alkali metal salt precipitate and any residual alkali metal. Unreacted alkali metal is deactivated with protic solvents, if necessary, and the alkali metal salts are extracted with water. These are examples. Examples of implementation:

[0032] A commercially available SpinPro Reactor from Flowid (Eindhoven, Netherlands, http: / / www.flowid.nl / spinpro-reactor / ) with three rotating disks and an integrated heat exchanger was used for the reactions. The distance between the rotating disks and the wall was 2 mm. The reactor volume was 230 ml. For all reactions, the reactor was evacuated 20 times to inertize and vented with 8 bar of nitrogen. For the synthesis of the polysilanes (Examples 1 and 2), a continuous stirred tank with a residence time of 20 min (flow 7.2 kg / h => 2.8 L; flow 10.8 kg / h => 4.1 L) was connected downstream of the SDRs. Comparison example:

[0033] Semi-batch process for the production of poly(methylphenylsilane):Using standard Schlenk technique, a 1000 mL four-necked flask equipped with a dropping funnel, reflux condenser, precision glass stirrer, and temperature sensor was evacuated and placed under argon. 215 g of xylene and 17.9 g of sodium were placed in the four-necked flask. The dropping funnel was also filled with 67.3 g of dichloromethylphenylsilane under an inert gas atmosphere. While slowly stirring, the flask was heated in an oil bath to approximately 102 °C so that the sodium was molten. The stirring speed was then set to exactly 300 rpm, and stirring was continued for about five minutes. After this time, a homogeneous, finely divided dispersion had formed (visual assessment). The dichlorophenylmethylsilane was added to this suspension over a period of approximately 30 minutes. The onset of the reaction was observed by an increase in temperature and an intense violet coloration of the reaction mixture.The dosing rate had to be selected so that the dichlorophenylmethylsilane was added evenly over the dosing time and at the same time the reaction temperature always remained within the temperature window of 102 - 106°C.

[0034] After the addition, the reaction mixture was stirred for a further 2 h at 102°C. The resulting suspension was cooled to room temperature and filtered under protective gas through a ceramic frit (G4). The filtrate was concentrated by distilling off the solvent mixture in vacuo to obtain the soluble portion of the formed poly(methylphenylsilane). The polymer was characterized by 1< H NMR, 13< C NMR, 29< Si NMR spectroscopy (each in C 6 D 6 ), and gel permeation chromatography (in THF with a light scattering detector). Ausbeute: 32 % Molmasse: 2000 g / mol 1< H-NMR (δ [ppm], CDCl 3 ): 6,5-7,5 ppm, 0,5 ppm. 13< C-NMR (δ [ppm], CDCl 3 ): 134-138 ppm, 125-130 ppm, 21 ppm. 29< Si-NMR (δ [ppm], CDCl 3 ): -41 ppm, -40 ppm, -39 ppm, +15 ppm. Example 1 - Continuous production of poly(methylphenylsilane):

[0035] To start the reaction, the SDR was set to a rotation speed of 1000 or 2500 rpm, a heating oil temperature of 100 or 105°C, and an initial xylene flow of 6.5 kg / h. Once a constant temperature had been established in the reactor, the sodium dosing was started. As soon as a gray dispersion was observed emerging into the collection vessel, the dosing of dichloromethylphenylsilane was started. The mass ratio of dichloromethylphenylsilane to sodium remained constant at 5:1 in all experiments. The onset of the reaction was immediately recognizable by the temperature increase on the first and second plate of the reactor. Later, the deep purple reaction mixture emerged into the collection vessel. The dosing rates and oil temperatures were varied as listed in the table.

[0036] The product was filtered under nitrogen through a G4-F ceramic filter, and the solvent was completely distilled off under vacuum. The polymer was characterized by 1< H NMR, 13< C NMR, 29< Si NMR spectroscopy (each in C 6 D 6 ) and gel permeation chromatography (in THF with light scattering). Speed ​​[rpm] T heating oil [°C] Total flow [kg / h] Solids content [%] T 1st / 2nd / 3rd plate [°C] Molar mass [g / mol] Yield of isopropyl polysilane [%] 1.1 2500 105 7,2 10 109 / 107 / 104 3100 46 1.2 -"- -"- 10,8 -"- 112 / 108 / 105 2900 43 1.3 2500 105 10,8 20 119 / 114 / 109 1900 35 1.4 -"- -"- 7,2 -"- 116 / 113 / 108 2200 38 1.5 1000 105 7,2 20 106 / 111 / 107 2400 41 1.6 -"- -"- 10,8 -"- 107 / 118 / 109 2100 37 1.7 2500 100 10,8 20 110 / 106 / 101 2900 42 1.8 -"- -"- 7,2 -"- 107 / 103 / 100 3200 47 1< H-NMR (δ [ppm], CDCl 3 ): 6.5-7.5 ppm, 0.5 ppm. 13<C-NMR (δ [ppm], CDCl 3 ): 134-138 ppm, 125-130 ppm, 21 ppm. 29<Si-NMR (δ [ppm], CDCl 3 ): -41 ppm, -40 ppm, -39 ppm, +15 ppm. Example 2 - Preparation of cyclic oligo(methylphenylsilane):

[0037] At a rotation speed of 2500 rpm, a heating oil temperature of 125°C, and a xylene flow rate of 6.5 kg / h, the sodium dosing was started at 2 g / min. The temperature in the reactor stabilized at 122°C. As soon as a gray dispersion was observed emerging from the reactor, the monomer dosing was started at 10 g / min. The onset of the reaction was immediately evident by the temperature rise in the reactor to 129°C on the first plate. Shortly afterward, the deep purple reaction mixture emerged into the collecting vessel. The product was filtered off under nitrogen, and the solvent was distilled off. The polymer was characterized by 1< H NMR, 13< C NMR, 29< Si NMR spectroscopy (each in C 6 D 6 ) and gel permeation chromatography (in THF with a light scattering detector). GPC (Elutionsmittel Toluol, RI-Detektor, Kalibrierung: Polysiloxan-Standard): 300 g / mol, 900 g / mol GPC (Elutionsmittel THF, LS-Detektor, probenspezifische Kalibrierung): 1300 g / mol, Ð=1,6 1< H-NMR (δ [ppm], CDCl 3 ): 6,5-7,5 ppm, 0,5 ppm. 13< C-NMR ([δ ppm], CDCl 3 ): 134-138 ppm, 125-130 ppm, 21 ppm. 29< Si-NMR (δ [ppm], CDCl 3 ): -41 ppm, -40 ppm, -39 ppm. Example 3 - Ring closure of 1,6-dibromohexane to cyclohexane:

[0038] At a rotation speed of 2500 rpm, a heating oil temperature of 110°C, and a xylene flow rate of 6.5 kg / h, the sodium dosing was started at 1.0 g / min. The temperature in the reactor stabilized at 122°C. As soon as a gray dispersion was observed emerging from the reactor, the dosing of 1,6-dibromohexane was started at 4 g / min. The start of the reaction was immediately evident by the temperature rise in the reactor to 127°C on the first plate. Shortly afterward, the deep purple reaction mixture emerged into the collecting vessel. The product was filtered off under nitrogen, the composition of the filtrate was analyzed by GC-MS, and a conversion of 98.5% was determined. The pure product was obtained by fractional distillation of the filtrate in 91% yield and analyzed by 1< H and 13< C NMR spectroscopy. 1<H-NMR (δ [ppm], CDCl 3 ): 1.44. 13<C-NMR (δ [ppm], CDCl 3 ): 26.9.

Claims

1. Use of a device for performing continuous chemical reactions for reacting finely disperse alkali metal dispersions in inert solvents, characterized by that a rotary disk reactor is employed as said device.

2. The use according to claim 1, characterized by that lithium, sodium, potassium, mixtures thereof and / or alloys thereof are employed as said alkali metal.

3. The use according to claim 1 or 2, characterized by that the chemical reaction is a Wurtz reaction.

4. The use according to claim 3, characterized by that mono-, di- or multifunctional halogen compounds of the elements of group 14 of the Periodic Table are employed as reactants for said Wurtz reaction.

5. The use according to claim 3 or 4 for preparing linear, branched and cyclic hydrocarbons from mono-, di- or multifunctional organic halogen compounds and mixtures thereof in a Wurtz reaction.

6. The use according to claim 4 or 5 for preparing polysilanes, especially polycarbosilanes, from mono-, di- or multifunctional halogen silanes and mixtures thereof.

7. The use according to claim 1 or 2, characterized by that the chemical reaction is an acyloin condensation.

8. The use according to claim 7, characterized by that organic mono-, di-, tri- or polyester compounds are employed as reactants for said acyloin condensation.

9. The use according to any of claims 1 to 8, characterized by that said rotary disk reactor has a downstream dwelling time unit.