EP2049246A1

EP2049246A1 - System and process for continuous industrial preparation of alkylalkoxysilanes

Info

Publication number: EP2049246A1
Application number: EP07787261A
Authority: EP
Inventors: Jürgen Erwin LANG; Georg Markowz; Dietmar Wewers; Harald Metz; Norbert Schladerbeck
Original assignee: Evonik Degussa GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2006-08-10
Filing date: 2007-07-09
Publication date: 2009-04-22
Also published as: WO2008017562A1; DE102007023756A1

Abstract

The present invention relates to a system, to a reactor and to a process for continuous industrial performance of a reaction wherein an a,ß-unsaturated olefin is reacted with an HSi compound B in the presence of a catalyst C and optionally of further assistants, and the system is based at least on the combination of reactants (3) for components A (1) and B (2), at least one multielement reactor (5) which, in turn, comprises at least two reactor units in the form of exchangeable pre-reactors (5.1) and at least one further reactor unit (5.3) connected downstream of the prereactors, and on a product workup (8).

Description

Plant and process for the continuous industrial production of alkylalkoxysilanes

The present invention relates to a novel reactor and a plant for the continuous industrial production of alkylalkoxysilanes by reacting an α _: ß-unsaturated olefin with a HSi compound and a related method.

Organosilanes, such as vinylchloro or vinylalkoxysilanes (EP 0 456 901 A1, EP 0 806 427 A2), chloroalkylchlorosilanes (DE-AS 28 15 316, EP 0 519 181 A1, DE 195 34 853 A1, EP 0 823 434 A1, EP 1 020 473 A2), alkylalkoxysilanes (EP 0 714 901 A1, DE 101 52 284 A1), fluoroalkylalkoxysilanes (EP 0 838 467 A1, DE 103 01 997 A1), aminoalkylalkoxysilanes (DE-OS 27 53 124, EP 0 709 391 A2 , EP 0 849 271 A2, EP 1 209 162 A2, EP 1 295 889 A2), glycidyloxyalkylalkoxysilanes (EP 1 070 721 A2, EP 0 934 947 A2), methacryloxyalkylalkoxysilanes (EP 0 707 009 A1, EP 0 708 081 A2), Polyetheralkylalkoxysilanes (EP 0 387 689 A2), and many more, are of great industrial and industrial interest. Processes and plants for their production have long been known. These products are comparatively small tonnage products and are predominantly produced in batch processes. As a rule, multiple-use systems are used in order to achieve the highest possible utilization of the batch systems. However, when changing the product consuming cleaning and rinsing of such batch systems are necessary. In addition, long residence times of the reaction mixture in a large-volume, expensive and labor-intensive batch system are often required in order to achieve sufficient yield. Furthermore, said reactions are often considerably exothermic with heat of reaction in the range of 100 to 180 kJ / mol. Therefore, in the implementation of undesirable side reactions can have a significant impact on selectivity and yield. If these reactions are hydrosilylations, the possible elimination of hydrogen places considerable demands on the safety technology. Furthermore, a starting material is often used in a semi-batch mode submitted together with the catalyst and the other reactant added. In addition, even small variations in the process control of batch or semi-batch plants can lead to a considerable diversification of the yields and product qualities via different approaches. If you want to transfer results from the laboratory / pilot plant scale to the batch scale (scale up), you often experience difficulties.

Microstructured reactors as such, for example for a continuous production of polyether alcohols (DE 10 2004 013 551 A1) or the synthesis of u. a. Ammonia, methanol, MTBE (WO 03/078052) are known. Also microreactors for catalytic reactions are known (WO 01/54807). However, so far the microreactor technology for the industrial production of organosilanes has been omitted or at least not realized. The tendency of alkoxy- and chlorosilanes to hydrolysis - even with small amounts of moisture - and corresponding caking in a Organosilanherstellungsanlage probably to be seen as a sustainable problem.

Therefore, the object was to provide a further possibility for the industrial production of alkylalkoxysilanes. In particular, there was a concern to provide a further possibility for the continuous production of such organosilanes, while endeavoring to minimize the disadvantages mentioned above.

The stated object is achieved according to the information in the claims.

In the present invention, it has surprisingly been found that the hydrosilylation of an HSi-containing component B, in particular a hydrogenalkoxysilane, with an α, ß-unsaturated olefin (component A) in the presence of a catalyst C in a simple and economical manner in a industrial scale and continuously in an on a multi-element reactor (5) based systems can perform advantageous, in particular the multi-element reactor (5) at least two reactor units in the form of interchangeable prereactors (5.1) and at least one further pre-reactors downstream reactor unit (5.3).

Thus, advantageously by the use of a multi-element reactor (5) in the present embodiment for continuous operation of the process according to the invention, since the present multi-element reactor (5) the targeted, regular exchange of pre-reactors in which deposits significant amounts of hydrolyzate after an operating time , allows against fresh pre-reactors even under operating conditions.

In this case, pre-reactors can be used in a particularly advantageous manner, which are equipped with packing, which even more targeted and effective separation of hydrolyzate or particles and thus a reduction in constipation tendency and downtime of the system can be achieved by deposits and caking in the reactor.

Unlike a batch approach, it is possible in the present invention, the educts vorzumischen immediately before the multi-element reactor continuously, while the pre-mixing can also be done cold, then heat in the multi-element reactor and there targeted and continuously implement. It is also possible to add a catalyst to the educt mixture. Subsequently, the product can be worked up continuously, z. As in a evaporation, rectification and / or in a Kurzweg- or thin-film evaporator - to name just a few options. In the multi-element reactor, the heat of reaction liberated during the reaction can be advantageously transferred via the large surface area of the interior walls of the reactor in relation to the reactor volume and, if provided, to a Heat transfer medium are dissipated. Furthermore, in the present application of multielement reactors, a significant increase in the space-time yield of fast, heat-dissipating reactions is possible. This is made possible by a faster mixing of the educts, a higher average concentration level of the starting materials than in the batch process, ie no limitation by educt depletion, and / or an increase in temperature, which can usually cause an additional acceleration of the reaction. In addition, the present invention enables the preservation of process reliability in a comparatively simple and economical manner. Thus, in the present invention, a drastic process intensification, in particular shortening of the process time under reaction conditions by more than 99% compared to the standard batch process can be achieved. At the same time, increased yields of up to 15% were achieved by higher conversions and selectivities. Preferably, the present reactions were carried out in a stainless steel multi-element reactor. Thus, for the implementation of said implementations can be dispensed with the use of special materials in an advantageous manner. In addition, can be determined by the continuous procedure in reactions to be carried out under pressure a longer service life of the metal reactors, since the material fatigue compared to a batch mode significantly slower. In addition, the reproducibility compared to comparable studies in batch processes could be significantly improved. In addition, there is a significantly reduced scale-up risk in the transfer of the results from the laboratory or pilot plant scale in the present method. In particular, in the present continuous process using a system according to the invention, wherein a multi-element reactor advantageously contains at least one interchangeable, preferably filled with preforms pre-reactor, a surprisingly long system life even without stoppages, which are caused by caking or deposits are made possible. Moreover, it has surprisingly been found that it is particularly advantageous in the present process, the multielement reactor before the start of the actual operation with the reaction mixture, in particular when this contains a homogeneous catalyst in an increased concentration to operate, ie preconditioned. By this measure, an unexpectedly rapid adjustment of constant process conditions can be effected at a high level. The present invention thus relates to a plant for the continuous industrial implementation of a reaction, wherein reacting an α, ß-unsaturated olefin A with an HSi compound B in the presence of a catalyst C and optionally further auxiliaries and the system at least on the Eduktzusammenführung (3 ) for the components A (1) and B (2), at least one multi-element reactor (5) which in turn contains at least two reactor units in the form of at least one replaceable prereactor (5.1) and at least one further reactor unit (5.3) connected downstream of the prereactor system, and based on a product work-up (8).

The present invention furthermore relates to a multielement reactor (5) for reacting hydrolyzable silanes, in particular those containing H-Si units, which in turn has at least two reactor units in the form of at least one replaceable prereactor (5.1) and at least one further reaction unit connected downstream of the prereactor system (5.3).

Pre-reactors (5.1) are preferred, which are equipped with Füllkörperπ. Suitable fillers are, for example-but not exclusively-structured fillers, ie regular or irregular particles of the same or different size, preferably having an average particle size, the average particle diameter of the cross-sectional area being ≦ 1/3, particularly preferably 1/5 to 1 / 200, most preferably 1/10 to 100, of the free cross section of each reactor unit (5.1) and the average particle cross-sectional area preferably 100 to 10 ^{~ 6} mm ² corresponds, such as chips, fibers / wool, spheres, splinters, strands with round or almost round or rectangular cross-section, spirals, cylinders, tubes, cups, saddles, honeycomb bodies, plates, meshes, fabrics, open-pored sponges, irregular shaped or hollow bodies, (structural) packings or containers of the aforementioned structural bodies, spherical bodies of metal, metal oxide, Ceramics, glass or plastic, said packing, for example - but not exclusively - of steel, stainless steel, titanium, copper, aluminum, titanium oxides, aluminum oxides, corundum, silicon oxides, quartz, silicates, clays, zeolites, alkali glass, boron glass, quartz glass, porous ceramics , glazed ceramics, special ceramics, SiC, Si ₃ N ₄ , BN, SiBNC, etc.

FIGS. 1 to 6 show flow diagrams of plants or plant parts as preferred embodiments of the present invention.

Thus, FIG. 1 shows a preferred continuous system in which the reactant components A and B are combined in unit (3), fed to unit (5), which may contain an immobilized catalyst, reacted therein and the reaction product in the unit (8) is worked up.

FIG. 2 shows a further preferred embodiment of an existing continuous plant in which a catalyst C, in particular a homogeneous catalyst, is fed to component B. However, the catalyst can also be fed to the unit (3) or, as can be seen in FIG. 3, the catalyst C metered into a mixture of the components A and B shortly before entry into the multi-reactor unit (5).

Furthermore, it is possible to add further auxiliaries optionally to the respective streams mentioned above.

Here, a unit of a reactor is understood as meaning an element of the multi-element reactor (5), each element having an area or reaction space for the said reaction represents, cf. for example, (5.1) (reactor unit in the form of a pre-reactor) in Figure 4 and (5.5) [reactor unit of an integrated block reactor (5.3.1)] in Figure 5 and (5.10) [reactor unit of a Mikrorohrbündelwärmetauscherreaktors (5.9)]. Ie. Reactor units of a multielement reactor (5) in the context of the present invention are in particular stainless steel or quartz glass capillaries, stainless steel tubes or well-dimensioned stainless steel reactors, for example pre-reactors (5.1), tubes (5.10) in microtube bundle heat exchanger reactors [e.g. B. (5.9)] and converted areas (5.5) in the form of integrated block reactors [z. Eg (5.3.1)]. In this case, the inner walls of the reactor elements may be coated, for example with a ceramic layer, a layer of metal oxides, such as Al ₂ O ₃ , TiO ₂ , SiO ₂ , ZrO ₂ , zeolites, silicates, to name only a few, but also organic polymers, in particular fluoropolymers, such as Teflon, are possible.

Thus, a plant according to the invention comprises one or more multi-element reactors (5), which in turn are based on at least 2 to 1,000,000 reactor units, including all natural numbers in between, preferably from 3 to 10,000, in particular from 4 to 1,000 reactor units.

In this case, the reactor or reaction space of at least one reactor unit preferably has a semicircular, semi-oval, round, oval, triangular, square, rectangular or trapezoidal cross-section perpendicular to the flow direction. Such a cross section preferably has a cross-sectional area of 75 μm ² to 75 cm ² . Particularly preferred are cross-sectional areas of 0.7 to 120 mm ² and all numerically intervening numerical values. For round cross-sectional areas, a diameter of> 30 μm to <15 mm, in particular 150 μm to 10 mm, is preferred. Square cross-sectional areas preferably have edge lengths of ≥ 30 μm to ≦ 15 mm, preferably 0.1 to 12 mm. In a multielement reactor (5) of an inventive Plant reactor units are present with different shaped cross-sectional areas.

Further, the structure length in a reactor unit, i. H. from entry of the reaction or product stream into the reactor unit, cf. z. B. (5.1 and 5.1.1) or (5.5 and 5.5.1), until the exit, cf. (5.1.2) or (5.5.2), preferably 5 cm to 500 m, including all numerically intervening numerical values, particularly preferably> 15 cm to 100 m, very particularly preferably 20 cm to 50 m, in particular 25 cm to 30 m. In a plant according to the invention, preference is given to reactor units whose respective reaction volume (also referred to as reactor volume, that is to say the product of cross-sectional area and structure length) is 0.01 ml to 100 l, including all numerically intervening numerical values. The reactor volume of a reactor unit of a system according to the invention is particularly preferably 0.05 ml to 10 l, very particularly preferably 1 ml to 5 l, very particularly preferably 3 ml to 2 l, in particular 5 ml to 500 ml.

Furthermore, systems according to the invention can be based on one or more multi-element reactors (5), which are preferably connected in parallel. However, said multi-element reactors (5) can also be switched one behind the other so that the product which originates from the preceding multi-element reactor can be fed to the inlet of the subsequent multi-element reactor.

Present multielement reactors (5) can advantageously be combined with a reactant component stream (4) or (5.2), which is suitably divided into the respective sub-streams, cf. z. B. (5.4) in Figure 5 and (5.11) in Figure 6, are fed. After the reaction, the product streams can be combined, cf. z. B. (5.7) in Figure 5, (5.12) in Figure 6 and (7), and then work up advantageously in a workup unit (8). In this case, such a processing unit (8) initially have a condensation stage or evaporation stage, which has a or several distillation stages.

Furthermore, a multielement reactor (5) of a plant according to the invention can be based on at least two stainless steel capillaries connected in parallel or on at least two quartz glass capillaries connected in parallel or at least one shell and tube heat exchanger reactor (5.9) or at least one integrated block reactor (5.3.1).

In particular, it is possible to use stainless steel capillaries, reactors or pre-reactors which advantageously consist of a high-strength, high-temperature-resistant and stainless steel; for example, but not exclusively, pre-reactors, capillaries, block reactors, shell-and-tube heat exchanger reactors, etc., are made of type 1 .4571 or 1.4462 steel, cf. In particular, the steel facing the reaction chamber surface of a stainless steel capillary or a multi-element reactor with a polymer layer, for example a fluorine-containing layer, including Teflon, or a ceramic layer, preferably an optionally porous SiO ₂ -, TiO ₂ - or AI ₂ O ₃ layer, in particular for receiving a catalyst, be equipped.

In particular, it is advantageously possible to use an integrated block reactor, as can be seen, for example, as a temperature-controllable block reactor constructed from defined metal plates (also referred to below as plane) from http://www.heatric.com/phe-construction.html ,

The production of said structured metal plates or planes, from which a block reactor can then be produced, can take place, for example, by etching, turning, cutting, milling, embossing, rolling, spark erosion, laser processing, plasma technology or another technique of the processing methods known per se. So with extreme precision well defined and specifically arranged structures, such as grooves or joints, incorporated on one side of a metal plate, in particular a metal plate made of stainless steel. In this case, the respective grooves or joints usually start on a front side of the metal plate, are continuous and usually end on the opposite end face of the metal plate. Sometimes the splitting also takes the form of a tree structure on the plate.

Thus, FIG. 5 shows a plane of an integrated block reactor (5.3.1) with a plurality of reactor units or elements (5.5). In this case, such a level usually consists of a base plate made of metal with metal walls thereon (5.6), the reaction chambers (5.5) together with a cover plate made of metal and a unit for temperature control (6.5, 6.6), preferably a further level or textured metal plate, limit. Furthermore, the unit (5.3.1) contains an area (5.4) for feeding and distributing the educt mixture (5.2) into the reactor elements (5.5) and a region (5.7) for combining the product streams from the reaction areas (5.5) and discharging the product stream ( 7). In addition, as part of an integrated block reactor (5.3.1), several such previously described levels may be connected one above the other. The bonding can be done for example by (diffusion) welding or soldering; for such and other working techniques applicable here cf. also www.imm-neurz.de/seiten/de/u_050527115034_2679.php?PHPSESSID=75a6285eb0433122b9c ecaca3092dadb. Furthermore, such integrated block reactors (5.3.1) are advantageously surrounded by a temperature control unit (6.5, 6.6), which enables the heating or cooling of the block reactor (5.3.1), ie a targeted temperature control. For this purpose, a medium (D), z. B. Marlotherm ^® or Mediatherm ^® , by means of a heat exchanger (6.7) tempered and fed via line (6.8) a pump (6.9) and line (6.1) of the temperature control (6.5) and via (6.6) and (6.2) removed and the heat exchanger unit (6.7). In this case, in an integrated block reactor (5.3.1) released reaction heat optimally by the shortest route control, which can avoid temperature peaks that adversely affect a targeted reaction. It is also possible to design the integrated block reactor (5.3.1) and the associated temperature control unit (6.5, 6.6) such that a temperature control plane is arranged between two reactor element planes, which guides the temperature control medium even more directionally between the areas (6.1, 6.5) and (6.6, 6.2).

In plants according to the invention, preference is given in particular to a multielement reactor (5) comprising at least one pre-reactor (5.1) and at least one further reactor unit (5.3), for example a stainless steel capillary, or a pre-reactor (5.1) and at least one integrated block reactor (5.3.1) or a Pre-reactor (5.1) and at least one micro tube bundle heat exchanger reactor (5.9) includes, cf. FIG. 4. Furthermore, the pre-reactor (5.1) is suitably tempered, that is H. cooled and / or heated, off (D, 6.3, 6.4).

As a rule, traces of water already lead to the hydrolysis of the alkoxy or chlorosilane educts and thus to deposits or caking. The particular advantage of such an embodiment of a prereactor (5.1) in the context of the multi-element reactor (5), in particular for the implementation of silanes, is that in addition to carrying out the continuous reaction by a targeted separation and discharge of hydrolyzates or particles unplanned Stillbzw , Can advantageously minimize downtime. Thus, the pre-reactors (5.1) equipped according to the invention can additionally be preceded and / or followed by filters for particle separation.

In general, a plant according to the invention for the continuous industrial implementation of reactions based on a Eduktzusammenführung (3) for the components A and B, at least one said multi-element reactor (5) and on a product work-up (8), cf. Figures 1, 2 and 3, wherein the multi-element reactor (5) at least two reactor units in the form of replaceable pre-reactors (5.1), which are preferably equipped with packing, and at least one further, the pre-reactor downstream reactor unit (5.3).

In this case, the educt components A and B can each be combined in a targeted manner from a storage unit by means of pumps and optionally by means of differential weighing system in the area (3). As a rule, components A and B are metered at ambient temperature, preferably at 10 to 40 ^° C., and mixed in region (3). But you can also preheat at least one of the components, both components or feedstocks or the corresponding mixture. Thus, the said storage unit can be conditioned and the storage containers can be designed to be temperature-controlled. Furthermore, it is possible to combine the educt components under pressure. Via line (4), it is possible to continuously feed the educt mixture to the multielement reactor (5).

In this case, the multielement reactor (5) is preferably brought to or maintained at the desired operating temperature by means of a temperature control medium D (6.1, 6.2) so that undesirable temperature peaks and temperature fluctuations known from batch systems are advantageously avoided or adequately achieved in the present system according to the invention can become low.

The product or crude product stream (7) is continuously the product work-up (8), for example, a rectification, fed, for example, over head (10) a low-boiling product F, for example, used in excess and optimally recyclable silane, and on the Swamp (9) a heavy boiling product E can continuously decrease. It is also possible to remove side streams as a product from the unit (8).

Is it necessary to react the components A and B in the presence of a Having to perform catalyst C, so you can use a homogeneous catalyst by metering into the educt stream in an advantageous manner. But you can also use a suspension catalyst, which can also be added to the reactant stream. The maximum particle diameter of the suspension catalyst should be less than 1/3, more advantageously 1%, preferably 1%, of the extent of the smallest free cross-sectional area of a reactor unit of the multielement reactor (5).

Thus, FIG. 2 reveals that it is advantageous to meter in a said catalyst C to component B before it is combined with component A in region (3).

It is possible to meter in a homogeneous catalyst C or a suspension catalyst C but also a mixture of A and B which is conducted in line (4), preferably just before entry into the multielement reactor via a line (2.2), cf. FIG. 3.

In the same way as in the case of a homogeneous catalyst, it is also possible to add further, predominantly liquid auxiliaries, for example but not exclusively, activators, initiators, stabilizers, inhibitors, solvents or diluents to the reactant components A and B, etc.

But you can also choose a multi-element reactor (5), which is equipped with an immobilized catalyst C, see. FIG. 1. In this case, the catalyst C can be present, for example-but not exclusively-on the surface of the reaction space of the respective reactor elements.

In general, a plant according to the invention for the continuous industrial implementation of the reaction of a said compound A with a compound B is optionally based in the presence of a catalyst and further auxiliaries at least one Eduktzusammenführung (3), at least one multi-element reactor (5), which in turn includes at least two reactor units according to the invention (5.1 and 5.3), and on a product processing (8). Suitably, the reactants or feedstocks are provided in a storage unit for carrying out the reaction and fed or metered as required. In addition, a system according to the invention is equipped with the measuring, metering, shut-off, transport, conveying, monitoring, control units and exhaust gas and waste disposal devices which are conventional in the art. In addition, such a system according to the invention can be advantageously accommodated in a portable and stackable container and handled flexibly. So you can bring a system according to the invention quickly and flexibly, for example, to the respective educt or energy sources. With a system according to the invention, but also with all the advantages, it is possible to continuously provide product at the point at which the product is further processed or used further, for example directly at the customer's.

Another particularly noteworthy advantage of a plant according to the invention for continuous industrial implementation of a reaction of α, ß-unsaturated compounds A with a HSi compound B is that it now has a possibility, even small specialty products with sales volumes between 5 kg and 50,000 t p. a., Preferably 10 kg to 10 000 t p. a., In a simple and economical way to produce continuously and flexibly. In this case, unnecessary downtime, the yield, the selectivity influencing temperature peaks and fluctuations and too long residence times and thus unwanted side reactions can be advantageously avoided. In particular, such an installation can also be used optimally for the production of existing silanes from an economical, ecological and customer-friendly point of view.

Thus, a further subject of the present invention is a method for continuous industrial production of an alkylalkoxysilane of the general formula (I)

H ₃ C (CH ₂ ) _x -Si (R ') _m (OR) ₃ - _m (I),

wherein R 'and R independently represent a C 1 to C ₄ alkyl group and x is an integer from the series 2 to 18 and m is 0 or 1,

wherein the reaction of the starting material components A and B is carried out in the presence of a catalyst C and optionally further components in a multi-element reactor (5), which in turn on at least two reactor units in the form of at least one interchangeable prereactor (5.1) and at least one further, the pre-reactor downstream reactor unit (5.3).

The reaction is preferably carried out in at least one multielement reactor (5) whose reactor units consist of stainless steel or quartz glass or whose reaction spaces are delimited by stainless steel or quartz glass, wherein the surfaces of the reactor units can be coated or occupied, for example with Teflon.

Furthermore, in the case of processes according to the invention, preference is given to using reactor units whose respective cross-section is semicircular, semi-oval, round, oval, triangular, square, rectangular or trapezoidal.

Advantageously, reactor units are used whose respective cross-sectional area is 75 μm ² to 75 cm ² .

Furthermore, preference is given to using those reactor units which have a structure length of 5 cm to 200 m, particularly preferably 10 cm to 120 m, very particularly preferably 15 cm to 80 m, in particular 18 cm to 30 m, including all possible Numerical values included from the aforementioned ranges.

Thus, in the process according to the invention, reactor units are suitably used whose respective reaction volume is 0.01 ml to 100 l including all numerically intermediate numerical values, preferably 0.1 ml to 50 l, particularly preferably 1 ml to 20 l, very particularly preferably 2 ml to 10 1, in particular 5 ml to 5 1.

In the process according to the invention, the said reaction can also advantageously be carried out in a plant with a multielement reactor (5) which (i) has at least two parallel-connected pre-reactors (5.1) and at least one stainless steel capillary downstream of the pre-reactors, or (ii) at least two shunts Prereactors (5.1) and at least one downstream of the pre-reactors quartz glass capillaries or (iii) on at least two parallel connected pre-reactors (5.1) and at least one integrated block reactor (5.3.1) or (iv) on at least two parallel connected pre-reactors (5.1) and at least one Shell-and-tube heat exchanger reactor (5.9) based.

In particular, preference is given to a multielement reactor (5) which contains at least two interchangeable pre-reactors (5.1) according to the invention, these being equipped with fillers, such as those listed above, for the separation of hydrolysed silanes used. The process according to the invention is particularly preferably carried out in reactor units made of stainless steel.

It is further preferred that in the process according to the invention the surface of the reactor units of the multielement reactor which is in contact with the starting material / product mixture is coated with a catalyst. If, in the context of the process according to the invention, the reaction of components A and B is carried out in the presence of a homogeneous catalyst C, it has surprisingly been found that it is particularly advantageous to pass the multielement reactor through one or more rinses with a mixture of homogeneous catalyst C and component B or Homogeπkatalysator C and the components A and B or a short-term operation of the plant, for example, for 10 to 120 minutes and optionally with a higher catalyst concentration, precondition.

The substances used for the preconditioning of the multielement reactor can be collected and later metered into the educt stream at least proportionally or fed directly to the product work-up and worked up.

By the above-described preconditioning of the multi-element reactor, especially if it consists of stainless steel, one can achieve a constant operating state with maximum yield in a surprising and advantageous manner more quickly.

In the process according to the invention, it is possible to carry out the said reaction in the gas and / or liquid phase. The reaction or product mixture can be present in one, two or three phases. In the process according to the invention, the reaction is preferably carried out in a single-phase, in particular in the liquid phase.

Thus, the inventive method or reaction is advantageously operated using a multi-element reactor (5) at a temperature of 10 to 290 ⁰ C at a pressure of 0.1 to 500 bar abs. The reaction of components A and B, in particular hydrosilylation, in the multielement reactor is preferably carried out during this process a temperature of 50 to 250 ⁰ C, preferably at 90 to 190 ⁰ C, more preferably 120 to 160 ⁰ C, in particular 135 to 145 ⁰ C, and at a pressure of 0.5 to 300 bar abs., Preferably at 1 to 200 bar abs., Particularly preferably at 2 to 100 bar abs., Most preferably at 10 to 50 bar abs., In particular at 15 to 35 bar abs., By.

In general, the differential pressure in a system according to the invention, d. H. between Eduktzusammenführung (3) and product work-up (8), 0.1 to 10 bar abs. Advantageously, one can equip a system according to the invention with a pressure-holding valve, in particular when using trimethoxysilane (TMOS). Preference is given to the pressure-holding valve from 1 to 100 bar abs., Preferably to 70 bar abs., Particularly preferably to 40 bar abs., In particular to a value between 10 to 35 bar abs., A.

The reaction can according to the invention at a linear velocity. (LV) of 1 to 1 ^■ 10 ⁴ h ^"1 i N. perform one. In this case, the flow velocity of the material stream is situated in the reactor units preferably in the range of 0.0001 to 1 m / s i. N., particularly preferably 0.005 to 0.7 m / s, in particular 0.05 to 0.3 m / s, and of all possible numbers within the abovementioned ranges If the ratio of reactor surface (A) prevailing in accordance with the invention is referred to the reactor volume (V), it is preferable to have an> A / V ratio of 20 to 5 000 m ² / m ³ - including all numerically possible individual values which are in the stated range - for advantageously carrying out the method according to the invention. Ratio is a measure of the heat transfer and possible heterogeneous (wall) influences.

Thus, the reaction in processes according to the invention is advantageously carried out with a mean residence time of ≦ 200 minutes, preferably 10 seconds to 60 minutes, more preferably 1 to 30 minutes, very particularly preferably 2 to 20 minutes, especially 3 to 10 minutes, through. Here again, all possible numerical values disclosed by the named area are referred to separately.

As component A, in the process according to the invention, for example-but not exclusively-the following α, β-unsaturated olefins or corresponding mixtures thereof can be used:

Butene-1, isobutene [H ₂ C = C (CH ₂ ) ₂ ], vinylcyclohexene-3, octene-1, isooctene, especially hexadecene-1.

Suitable components B in the process according to the invention are silanes of the general formula (II)

HSi (R ') _m (OR) ₃ - _m (II),

wherein R 'and R are independently a C 1 to C ₄ alkyl group and m is 0 or 1, preferably R' is methyl and as R is preferably methyl or ethyl.

Thus, according to the invention, preference is given to using trimethoxysilane (TMOS), triethoxysilane (TEOS), methyldimethoxysilane or methyldiethoxysilane.

The components A and B are preferably employed in the process according to the invention in a molar ratio A to B of 1: 5 to 100: 1, more preferably 1: 4 to 5: 1, very preferably 1: 2 to 2: 1, including all possible numbers within the previously mentioned areas. In particular, the procedure is preferred with an excess of olefin component, for example 1: 0.1 to 0.5. The process according to the invention is preferably carried out in the presence of a homogeneous catalyst C. However, it is also possible to operate the process according to the invention without the addition of a catalyst, in which case a clear decrease in the yield is generally to be expected.

In particular, the process according to the invention is used for carrying out a hydrosilylation reaction for the preparation of organosilanes according to formula (I), in particular homogeneous catalysts from the series Pt complex catalyst, for example those of the Karstedt type, such as Pt (0) -divinyltetramethyldisiloxane in xylene, PtCl _4, H ₂ [PtCl _6] and H ₂ [PtCl _6] ^■ 6H ₂ O, preferably a "Speyer catalyst", cis- (Ph ₃ P) ₂ PtCl ₂ complex catalysts of Pd, Rh, Ru, Cu, Ag, Au, Ir or those of other transitional or noble metals, which may be the per se known complex catalysts in an organic, preferably polar solvent for example but not exclusively ethers, such as THF, ketones, such as acetone, alcohols, such as Isopropanol, aliphatic or aromatic hydrocarbons, such as toluene, xylene, solve.

In addition, one can add to the homogeneous catalyst or the solution of Homogenkatalyators an activator, for example in the form of an organic or inorganic acid such as HCl, H ₂ SO ₄ , H ₃ PO ₄ , mono- or dicarboxylic acids, HCOOH, H ₃ C-COOH , Propionic Acid, Oxalic Acid, Succinic Acid, Citric Acid, Benzoic Acid, Phthalic Acid - just to name a few.

In addition, the addition of an organic or inorganic acid to the reaction mixture can take on another advantageous function, for example as a stabilizer or inhibitor of impurities in the trace range.

If a homogeneous catalyst or a suspension catalyst is used in the process according to the invention, the olefin component A is added to the catalyst, based on the metal, preferably in a molar ratio of from 2,000,000: 1 to 1,000: 1, more preferably from 1,000,000: 1 to 4,000: 1, in particular from 500,000: 1 to 10,000: 1, and all possible numerical values within the aforementioned ranges.

However, it is also possible to use an immobilized catalyst or heterogeneous catalyst from the series of transition metals or noble metals or a corresponding multielement catalyst for carrying out the hydrosilylation reaction. So you can, for example - but not exclusively - use precious metal sludge or precious metal on activated carbon. But you can also provide a fixed bed for receiving a heterogeneous catalyst in the field of multi-element reactor. Thus, for example-but not exclusively-heterogeneous catalysts which are supported on a carrier, such as spheres, strands, pellets, cylinders, stirrers, etc., inter alia SiO ₂ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , in the reaction region of the reactor units contribute.

Examples of integrated fixed bed catalyst block reactors are available at http://www.heatric.com/iqs/sid.0833095090382426307150/mab_reactors.html.

Furthermore, solvents or diluents, such as alcohols, aliphatic and aromatic hydrocarbons, ethers, esters, ketones, CHCs, CFCs - to name but a few - can be used as auxiliaries. Such adjuvants can be removed from the product, for example, in the product work-up.

Likewise, inhibitors, for example polymerization inhibitors or corresponding mixtures, can be used as additional auxiliaries in the present process. In general, the process according to the invention is carried out as follows:

As a rule, the reactant components A, B and, if appropriate, C are metered in, and optionally further auxiliaries, and the mixture is mixed. It is endeavored to meter a homogeneous catalyst with an accuracy of ≤ ± 20%, preferably ≤ ± 10%. In special cases, it is also possible to meter the homogeneous catalyst and optionally further auxiliaries into the mixture of components A and B only shortly before entry into the multielement reactor. Subsequently, it is possible to feed the starting material mixture to the multielement reactor and to react the components under temperature control. However, it is also possible first to rinse or precondition the multielement reactor with a catalyst-containing educt or reactant mixture before the temperature is advanced to carry out the reaction. It is also possible to carry out the preconditioning of the multielement reactor at a slightly elevated temperature. The product streams (crude product) combined or obtained in the multielement reactor can subsequently be worked up in a suitable manner in a product work-up of the plant according to the invention. The process is preferably operated continuously. The work-up can be carried out, for example-but not exclusively-by distillation with rectification.

Thus, the inventive method using a system according to the invention advantageously continuously with a product output of 5 kg to 50 000 t p. a. operate and for example - but not exclusively - hexadecyltrimethoxysilane advantageously produce. The present invention will be further illustrated by the following example without limiting the subject matter.

example

Preparation of hexadecyltrimethoxysilane The plant used for the continuous production of hexadecyltrimethoxysilane (Dynasylan "9116) consisted essentially of the educt reservoirs, HPLC pumps, control, measuring and metering units, a T-mixer, four parallel, exchangeable and filled with Vorreaktoren stainless steel (each diameter 10 mm, length 50 mm, stainless steel beads with an average diameter of 1, 5 mm as filler), an integrated block reactor made of stainless steel (hold up of about 200 cm ³ ), see also Figure 5, temperature control, a pressure-maintaining valve, a stripping column operated with N ₂ and connecting lines in the educt feed system, between the abovementioned plant sections and product, recycling and exhaust gas removal.

First, at room temperature, hexadecene-1 (purity 93%, Degussa AG) and an acetone, HOAc-containing solution of H ₂ PtCl ₆ -OH ₂ O (53 g in 1 l of acetone) in a molar ratio of olefin: Pt = 12,500 : 1 metered or mixed and mixed in the T-mixer with trimethoxysilane (TMOS, Degussa AG) in a molar ratio of olefin: TMOS = 1: 0.15 and fed to the reactor system. The pressure was 25 ± 10 bar. When starting up the system, the system should be kept as free of H ₂ O as possible. Furthermore, the system was rinsed for 2 hours prior to raising the temperature in the reactor with educt mixture. At a throughput of a total of 10 kg / h, the temperature was advanced in the reactors, set to 140 ⁰ C and operated continuously for 14 days. After reactor samples were taken at intervals for GC-WLD measurements. The conversion based on the olefin was on average 35% (including rearranged olefin) and the selectivity based on TMOS was 99%. The crude product thus obtained was run continuously into the thin-film evaporator operated under a vacuum, product was taken continuously from the bottom and stripping by means of inert gas removed residual TMOS.

Claims

claims:

1 . Plant for the continuous industrial implementation of a reaction, which reacts an α, ß-unsaturated olefin A with an HSi compound B in the presence of a catalyst C and optionally further auxiliaries and the system at least on the Eduktzusammenführung (3) for the components A (1 ) and B (2), at least one multi-element reactor (5) which in turn contains at least two reactor units in the form of at least one replaceable prereactor (5.1) and at least one further reactor unit (5.3) connected downstream of the prereactor system, and based on a product work-up (8) ,

2. Plant according to claim 1, characterized by a reactor unit (5.3), which in turn includes 1 to 100 000 reactor units.

3. Plant according to claim 1 or 2, characterized by

Reactor units, wherein a prereactor (5.1) has a free reaction volume of 5 ml to 10 1 and a reactor unit (5.3) in sum a free reaction volume of

1 ml to 100 l.

4. Plant according to one of claims 1 to 3, characterized by at least one multi-element reactor (5), the (i) on at least two parallel-connected pre-reactors (5.1) and at least one pre-reactors downstream stainless steel capillaries or (ii) on at least two parallel-connected pre-reactors (5.1) and at least one downstream of the pre-reactors quartz glass capillaries or (iii) on at least two parallel connected pre-reactors (5.1) and at least one integrated block reactor (5.3.1) or (iv) is based on at least two parallel connected pre-reactors (5.1) and at least one microtube bundle heat exchanger reactor (5.9).

5. Plant according to one of claims 1 to 4, characterized by at least two pre-reactors (5.1), which are equipped with packing.

6. Plant according to one of claims 1 to 5, characterized by a Multielementreaktor (5), the four to eight parallel connected and packed with packing pre-reactors (5.1) and a downstream of the pre-reactors integrated block reactor (5.3.1), in turn, 10 bis 4,000 reactor units (5.5) includes.

7. Multielementreaktor (5) for the implementation of hydrolyzable silanes, in turn, at least two reactor units in the form of replaceable pre-reactors

(5.1) and at least one further pre-reactor downstream reactor unit (5.3) includes.

8. Plant according to one of claims 1 to 6 or Mulielementreaktor according to claim 7, characterized by

Pre-reactors (5.1) packed with structured packing (5.1.3).

9. Process for the continuous industrial production of an alkylalkoxysilane of the general formula (I)

H ₃ C (CH ₂ ) _x -Si (R ¹ ) _m (OR) ₃ - _m (I),

wherein R 'and R independently represent a C _r to C ₄ alkyl group and x is a natural number from the series of 2 to 18 and m equals 0 or 1,

wherein the reaction of the Eduktkomponeπten A and B in the presence of a catalyst C and optionally further components in a multi-element reactor (5) performs, in turn, at least two reactor units in the form of at least one interchangeable prereactor (5.1) and at least one further, the pre-reactor downstream reactor unit (5.3).

10. The method according to claim 9, characterized in that one carries out the reaction in at least one multi-element reactor (5), wherein the reactor units are made of stainless steel and at least two of the pre-reactors (5.1) with packing (5.1 .3) are equipped.

11. A method according to claim 9 or 10, characterized in that as component A is an α, ß-unsaturated olefin having 3 to 18 carbon atoms with a silane (component B) of the general formula (II)

HSi (R ') _m OR ₃ - _m (II),

R 'and R are independently a C 1 to C ₄ alkyl group and m is 0 or 1,

implements.

12. The method according to any one of claims 9 to 1 1, characterized in that the components B (hydrogen silane) and A (α, ß-unsaturated olefin) in a molar ratio of 0.1 to 2 to 1.

13. The method according to any one of claims 9 to 12, characterized in that one uses a homogeneous catalyst C and this, based on the noble metal, in a molar ratio to the component A from 1 to 6 to 60,000.

14. The method according to any one of claims 9 to 13, characterized in that the reaction in the presence of a catalyst C on the basis of

PtCl _4, H ₂ PtCl ₆ or PtCl ₂ H ₆ ^■ 6H ₂ O, cis- (Ph ₃ P) ₂ PtCl _2, Pt (O) -

Divinyltetramethyldisiloxane or complex catalysts of Pd, Rh, Ru, Cu, Ag, Au or Ir performs.

15. The method according to any one of claims 9 to 14, characterized in that preconditioning the Mulitielementreaktor (5) with a catalyst-containing Eduktgemisch.

16. The method according to any one of claims 9 to 15, characterized in that the reaction in the multi-element reactor (5) at a temperature of 50 to 290 ⁰ C and at a pressure of 10 to 100 bar abs. operates.

17. The method according to any one of claims 9 to 16, characterized in that one carries out the reaction at an average residence time of 1 minute to 200 minutes.

18. The method according to any one of claims 9 to 17, characterized in that one carries out the reaction at a ratio of reactor surface to reactor volume (A / V) of 20 to 50 000 m7m ³ .

19. The method according to any one of claims 9 to 18, characterized in that one dosed and mixes the educt components A, B and C continuously, then a defined volume flow of the educt mixture to the multi-element reactor (5) feeds, and reacts the resulting product mixture subsequently processed.

20. The method according to any one of claims 9 to 19, characterized in that one uses a Eduktgemisch based on the components A, B and C, which contains as further component an organic or inorganic acid.

21. Method according to one of claims 9 to 20, characterized in that the further component is an organic carboxylic acid, preferably

Acetic acid, and one sets the molar ratio of acetic acid to component A to 0.01 to 5 to 10 000.

22. The method according to any one of claims 9 to 21, characterized in that after a defined operating time of the system at least one pre-reactor (5.1), which is optionally packed with packing (5.1.3), against a fresh, optionally equipped with packing prereactor while replacing at least one further prereactor (5.1) to carry out the continuous process continues.

23. The method according to any one of claims 9 to 22, characterized in that the flow velocity in the pre-reactors (5.1) is lower than that in the downstream reactor units.