Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
  • C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
  • C08G65/26—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds
  • C08G65/2696—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds characterised by the process or apparatus used
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/48—Polyethers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/48—Polyethers
  • C08G18/4866—Polyethers having a low unsaturation value
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
  • C08G65/34—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from hydroxy compounds or their metallic derivatives

Definitions

• the invention relates to a process for the preparation of polyether polyols in a reaction unit having a plurality of mutually parallel layers which are microstructured.
• Polyether polyols are in particular raw materials for the production of polyurethanes.
• EP-A 1 586 372 describes a microstructured reactor and its use in a process for the preparation of polyether alcohols by ring-opening addition of short-chain alkylene oxides in the presence of a solid catalyst, wherein the chemical process takes place in spaces of two or more substantially planparellelen plates or layers are formed and wherein the Eduktvermischung single phase liquid takes place individually in each reaction channel, a heat exchange device is provided and the reactor at pressures up to 800 bar and temperatures in the range of 30 to 400 ° C is designed.
• the potential of the highest possible reaction rates can be optimally utilized by high alkylene oxide pressures and polyether alcohols of uniform quality and with a low content of by-products can be produced.
• microstructured apparatuses are very difficult structures; even during production, the tolerances are such that the pressure loss of the individual capillaries among one another results especially for reaction systems with markedly increasing viscosity over the reaction time, as is the case in the present production of polyetherpolyols Maldistribution of the mass flows.
• This problem is in C. Amador et al. in Chem. Eng. J. 101 (2004) 1-3, pages 379-390.
• the avoidance of Maldistributionen parallel circuit Rohrapparaten was tried in the 80s. Approaches have been developed which promote even distribution in viscosity building systems. As with the feed to the microstructured reactor, the pressure losses of the individual capillaries must be taken into account, this effect must also be taken into account in the subsequent dosing.
• each layer has a plurality of channels arranged parallel to each other, one continuous from one side of the plate to the opposite side thereof Forming a flow path, wherein a part of the reactants or all reactants and optionally the catalyst at a temperature which is lower than the temperature of the reaction, premixed in a mixer outside the channels and then fed to the channels in the layers A on one side thereof and on the other side of the same the reaction mixture are withdrawn and wherein fed through the channels of planes arranged alternately to the planes A levels B on one side of a heat carrier and withdrawn on the other side thereof, which is characterized in that for the channels of the Layers A at one end de one of them
• Distributor for the supply of the educts and the catalyst and at the other end thereof a collecting means for the reaction mixture is provided.
• the preparation of the polyether polyols in the process according to the invention is carried out by reacting the following reactants:
• alkylene oxides can be used as starting materials. Preference is given to using one or more substances selected from the following list: ethylene oxide, propylene oxide, butylene oxide, pentenoxide, glycidyl ether, hexene oxide and / or styrene oxide, preferably ethylene oxide, propylene oxide, carbon dioxide and mixtures thereof.
• ethylene oxide, propylene oxide, butylene oxide, pentenoxide and hexene oxide all isomers can be used in pure form or as mixtures of the isomers.
• Carbon dioxide may preferably be used in an amount of up to 25% by weight, based on the weight of the polyether alcohol.
• H-functional starter or starter substances are preferably one or more alcohols having a functionality of 1 to 8, preferably from 2 to 8, more preferably from 2 to 6, more preferably from 2 to 4.
• one or more substances from the following list can be used: ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, sucrose, sucrose, glucose, fructose, mannose, sorbitol, hydroxyalkylated (meth) acrylic acid derivatives and alkoxylated Derivatives of the above-mentioned H-functional starter substances up to a molecular weight of about 1, 500 D.
• primary and / or secondary amines and thiols can serve as starters.
• compounds which contain both OH and allyl or vinyl groups for example allyl alcohol and its etherification products with polyhydric alcohols, and which can serve as starting materials in a subsequent free-radical polymerization.
• H-functional starter substances or starter substances it is also possible to use one or more alcohols having a functionality of 1 with the general formula R-OH, where R is a saturated or unsaturated alkyl, aryl, aralkyl or alkylaryl radical having 1 to 60 , preferably 1 to 24 carbon atoms, in particular one or more substances from the following list: methanol, butanol, hexanol, heptanol, octanol, decanol, undecanol, dodecanol or tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, butenol, hexenol, Heptenol, octenol, nonenol, decelene, undecenol, vinyl alcohol, allyl alcohol, geraniol, linalool, citronellol, m
• multimetal cyanide complex catalysts or alkali metal and alkaline earth metal hydroxides preferably potassium hydroxide and cesium hydroxide, and also other basic catalysts, such as alkali metal alkoxides or amines, can be used as catalysts.
• soluble basic catalysts it is also possible to use insoluble basic catalysts, such as magnesium hydroxide or hydrotalcite.
• Suitable multimetal cyanide complex catalysts are in particular double metal cyanide catalysts (DMC), which are known and described, for example, in WO 01/083107. They usually have the general formula (I)
• M 1 is a metal ion selected from the group containing Zn 2+ , Fe 2+ , Co 3+ , Ni 2+ , Mn 2+ , Co 2+ , Sn 2+ , Pb 2+ , Mo 4+ , Mo 6+ , Al 3+ , V 4+ , V 5+ , Sr 2+ , W 4+ , W 6+ , Cr 2+ , Cr 3+ , Cd 2+ , Hg 2+ , Pd 2+ , Pt 2+ , V 2+ , Mg 2+ , Ca 2+ , Ba 2+ , Cu 2+ ,
• M 2 is a metal ion selected from the group consisting of Fe 2+ , Fe 3+ , Co 2+ , Co 3+ , Mn 2+ , Mn 3+ , V 4+ , V 5+ , Cr 2+ , Cr 3+ , Rh 3+ , Ru 2+ , Ir 3+
• A is an anion selected from the group consisting of halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate, isocyanate, cyanate, carboxylate, oxalate or nitrate,
• X is an anion selected from the group comprising halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate, isocyanate, cyanate, carboxylate, oxalate or nitrate,
• L is a water-miscible ligand selected from the group comprising alcohols, aldehydes, ketones, ethers, polyether esters, ureas, amides, nitriles, lactones, lactams and sulfides,
• a, b, c, d, g and n are selected so as to ensure the electroneutrality of the compound
• e is the coordination number of the ligand or O
• f is a fractional or integer greater than or equal to O, as well as
• h is a fractional or integer greater than or equal to 0.
• the preparation of these compounds is carried out according to well-known methods by the aqueous solution of a water-soluble metal salt with the aqueous solution of a Hexacyanometallattagen, in particular a salt or an acid, hereinafter also referred to as educt solutions, combined and optionally thereto during or after the combination of a water-soluble Ligands exist.
• aqueous solution of a water-soluble metal salt with the aqueous solution of a Hexacyanometallattagen, in particular a salt or an acid, hereinafter also referred to as educt solutions, combined and optionally thereto during or after the combination of a water-soluble Ligands exist.
• Such catalysts and their preparation are described, for example, in EP 862,947 and DE 197,42,978.
• the multimetal cyanide compounds preferably have a crystalline structure. Their particle size is preferably in the range between 0.1 and 100 microns. A particular advantage of the crystalline DMC catalysts, especially those prepared using
• the preparation of the polyether alcohols can be carried out with a smaller amount of catalyst.
• the amount used in this case usually corresponds to the amount of multimetal cyanide compounds in the final polyether alcohol.
• the complicated separation of the multimetal cyanide compounds from the polyether alcohol after the preparation can thus be dispensed with.
• the multimetal cyanide compounds are preferably used in the form of suspensions, the multimetal cyanide compounds being suspended in organic compounds, preferably alcohols.
• organic compounds preferably alcohols.
• the catalyst suspension should have concentrations between 0.5 and 10%.
• the DMC catalysts are highly active. So far, DMC catalysts are mainly used in semi-batch reactors or continuous backmixed reactors (usually stirred tank reactors). However, with this reactor concept, the possible high reaction rate of the DMC catalysts is not taken into account; rather, a limitation of the maximum reaction rates often takes place due to the limited heat removal performance of these types of reactors, whereby both reactors with internal cooling coils and those with external heat exchangers are limited.
• the concentration of the catalysts if they are Multimetallcyanidkomplex- catalysts, depending on the H-functional starter substances used, often in a range between 5 and 5,000 ppm, based on the total weight of the starting materials.
• Alkali metal alcoholates as catalysts are usually used in higher concentrations, for example 100 to 50,000 ppm, based on the total weight of the starting materials.
• reaction products are carried out in the presence of multimetal cyanide complex catalysts, it is advantageous to use together with or in place of the alcohols mentioned as H-functional initiators, their reaction products with alkylene oxides, in particular with propylene oxide, preferably reaction products having a molecular weight of up to 500 g / mol.
• the addition of the alkylene oxides for the preparation of the reaction products can be carried out with any catalysts, for example with basic or Lewis acid catalysts.
• the starting materials are preferably used in a ratio of 1 to 300 equivalents of starting materials a) (one or more alkylene oxides and optionally carbon dioxide), to reactants b) (one or more H-functional starter substances).
• part or all of the starting materials and optionally the catalyst are first premixed outside the channels, it being ensured that the temperature during the premixing is lower than the temperature of the subsequent reaction.
• laminar diffusion mixers for example, laminar diffusion mixers, multilamination mixers, micromixers with structured walls or split recombine mixers are suitable for this purpose.
• the mixing of partial flows of the fluid which has been fanned on a microstructure into a multitude of microscopically small flow lamellae with a thickness in the range of 10 to 2,000 ⁇ m, or 20 to 1,000 ⁇ m or even 40 to 500 ⁇ m, takes place. exclusively by molecular diffusion perpendicular to the main flow direction.
• Laminar diffusion mixers can be designed as simple T or Y mixers or as so-called multilamination mixers.
• the two partial streams to be mixed are fed through a T or Y-shaped arrangement to a single channel.
• Decisive for the transversal diffusion path So « is the channel width ⁇ ⁇ .
• very short mixing times of less than 100 ms result for gases, whereas for liquids these are within the minute range.
• it is advantageous to additionally support the mixing process for example by flow-induced cross-mixing.
• the partial streams to be mixed are geometrically separated in a distributor into a multiplicity of stream threads and then fed alternately into lamellas of the mixing section at the outlet of the distributor.
• mixing times in the range of seconds are achieved with the classical multilamination mixers. Since this is not sufficient for some applications (eg in the case of rapid reactions), the basic principle has been developed further so that the flow lamellae are additionally focused geometrically or hydrodynamically. In the case of geometric focusing, this is done by a narrowing in the mixing section and in the hydrodynamic focusing by two side streams, which flow perpendicular to the main flow and thus further compress the flow lamellae.
• the focussing described makes it possible to realize lateral dimensions of the flow lamellae of a few micrometers, so that even liquids can be mixed within a few 10 ms.
• secondary structures are arranged on the channel walls, for example grooves or webs, at a certain angle to the main flow direction, preferably of 45 ° or 90 °.
• Split recombine mixers are characterized by stages of recurring separation and merging of currents. In each of these stages, the number of slats is successively doubled, halving the slat thickness and the diffusion path.
• an alkylene oxide for example propylene oxide and the catalyst, for example a multimetal cyanide complex catalyst, are premixed and the H-functional starter substance or the H-functional starter substances are added only in a second mixing step.
• the residence time in the process stage of the premixing is preferably in the range of 1 to 300 seconds.
• the premixed starting materials are fed to a reaction unit which contains a plurality of parallel, alternately stacked and microstructured layers of reaction channels and tempering channels, such that each layer has a multiplicity of channels arranged parallel to one another, from one side of the layer to the opposite side the same form a continuous flow path.
• a largely two-dimensional, planar structural unit is understood as a layer, that is to say a constructional unit whose thickness is negligibly small in relation to its area. This is preferably a substantially flat plate.
• the layers, in particular plates, are microstructured in that they have channels through which the reaction mixture (so-called reaction channels) or heat transfer medium (so-called temperature control channels) flows.
• reaction channels reaction channels
• temperature control channels heat transfer medium
• microstructuring is understood, as usual, to mean that the mean hydraulic diameter of the channels is ⁇ 1 mm.
• the channels in the layers A on one side of the same is supplied and withdrawn on the other side thereof the reaction mixture.
• layers B are arranged, to which a heat carrier is fed on one side thereof and withdrawn on the other side thereof.
• the alternating arrangement of the layers A, B it is possible for the alternating arrangement of the layers A, B to be designed such that each layer A is followed by a plane B, or that two successive layers A are followed by a layer B or two successive layers B one layer A follows.
• a distribution device for the supply of the educts and the catalyst and at the other end thereof a collecting means for the reaction mixture is provided.
• the distribution and collection device is in each case designed as a chamber arranged outside or inside the stack of the layers A, B.
• the walls of the chamber may be bent straight or semicircular, for example. It is essential that the geometric shape of the chamber is adapted to make flow and pressure loss so that a uniform flow through the channels is achieved.
• the distribution and collection devices are each arranged within the stack of layers A, B, in that the mutually parallel channels of each layer A in the region of each of the two ends thereof each have one, the transverse channel connecting mutually parallel channels and all transverse channels within the stack of layers A, B are connected by a substantially perpendicular to the plane of the layers A, B arranged collecting channel.
• the same principle of equal distribution applies to these channels, as explained in the previous paragraph.
• the method is preferably operated in such a way that the pressure in the channels of the layers A in the range of 10 to 200 bar absolute, the temperature in the range of 60 to 200 0 C and the residence time of the reaction mixture is between 1 and 600 seconds. In a variant of the method, work is carried out at a pressure of less than 60 bar.
• a temperature profile is run along the channels of each layer A, in which two or more heating or cooling zones per location with at least one distribution and collection device per heating or cooling zone of the layers B. are provided for the corresponding temperature of the reaction mixture in the channels of the layers A.
• reaction mixture is carried out with DMC catalysts, it is advantageous in one embodiment to recycle the reaction mixture from the collector of the layers A into a mixer arranged upstream of the reactor. Preferably, a proportion of 0.01 to 75% by weight of the reaction mixture is recycled to a mixer upstream of the reaction unit. As a result, a significant increase in the reaction rate can be achieved and a reduction in the residence time, so that frequently a higher productivity can be achieved.
• the invention also provides a process for preparing polyetherols by reacting the following starting materials:
• the first reaction mixture is preferably tempered after leaving the first reaction unit
• a multimetal cyanide complex catalyst is used as the catalyst.
• the reaction effluent of the single or the last of the plurality of reaction units is fed to a membrane separation unit and separated into a catalyst-rich stream (retentate) and into a catalyst-free stream (permeate or filtrate).
• the membrane process makes it possible, in particular, to enrich the catalyst by a factor of 2 to 100.
• the catalyst concentrate is recycled to the reactor, with the elimination of small amounts, in particular in the range of 0.1 to 3%, to avoid the accumulation of residues.
• the filtrate (product) is taken from the reaction system.
• Suitable membrane processes are micro- or cross-flow filtration and ultrafiltration.
• the membranes used have pore diameters in the range between 1 nm and 1 .mu.m and preferably between 2 nm and 0.1 .mu.m.
• the separating layers of the filter membranes can be made of, for example, organic polymers, ceramics, me- tall, carbon or combinations thereof and must be stable in the reaction medium at process temperature. Preference is given to inorganic membranes.
• the separating layers are usually applied to a single or multilayer porous substructure which consists of the same or at least one different material, such as the separating layer. Examples are:
• Ceramic for example, OC-Al2O3, ZrO ⁇ , TiO ⁇ , SiC or mixed ceramic materials and as polymers, for example, polytetrafluoroethylene, polyvinylidene fluoride, polysulfones, polyethersulfones, polyetheretherketones or polyamides can be used.
• the invention also provides the use of the polyetherols prepared by the process described above for the preparation of polyurethanes.
• the invention also relates to the use of the polyetherols prepared by the process described above as: surface-active substances, detergents and cleaners, mining chemicals, oil field chemicals, textile auxiliaries, leather processing aids, coating additives, formulation auxiliaries for crop protection agents, auxiliaries for cosmetics and Personal Care, formulation excipients for human and animal nutrition, formulation excipients for pigments, formulation auxiliaries for pharmaceuticals or fuel additives.
• the inventive method is characterized in particular by a further avoidance or reduction of Maldistributionen in the channels of a microstructured reactor over known methods. Accordingly, improvements in the yields and selectivities as well as the product properties can be achieved by the process according to the invention.
• improvements in the yields and selectivities as well as the product properties can be achieved by the process according to the invention.
• complete conversion can be achieved with the process according to the invention and the content of high molecular weight by-products can be reduced compared with known processes which lead to no or very low conversion.
• the products obtained are distinguished from products of known processes, in particular by a lower viscosity with the same molecular mass.
• Examples 4 to 8 membranes were used, each with different separation layers (a micro- and an ultrafiltration membrane), which are each listed in the examples, together with the respectively achieved concentration of the original 450 ppm DMC-containing suspension in column 1, the temperature of Membrane crossflow filtration in column 2, the flow rate across the membrane in column 3, the transmembrane pressure (arithmetic mean of feed and retentate pressure minus the permeate pressure) in column 4 and the specific flux through the membrane in column 5.
• Examples 4 to 8 show that it is possible to concentrate the suspension to concentrations which allow recycling of the suspension into the process.
• Example 4 Micro- or cross-flow filtration
• Example 5 Micro- or cross-flow filtration

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Polyethers (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 2007
  • 2007-05-22 MX MX2008014818A patent/MX2008014818A/es active IP Right Grant
  • 2007-05-22 CN CNA2007800236277A patent/CN101479317A/zh active Pending
  • 2007-05-22 EP EP07729399A patent/EP2027180A1/de not_active Withdrawn
  • 2007-05-22 KR KR1020087030388A patent/KR20090014296A/ko active IP Right Grant
  • 2007-05-22 JP JP2009511510A patent/JP2009537687A/ja active Pending
  • 2007-05-22 SG SG2008008569A patent/SG147866A1/en unknown
  • 2007-05-22 US US12/302,162 patent/US8034980B2/en not_active Expired - Fee Related
  • 2007-05-22 WO PCT/EP2007/054960 patent/WO2007135154A1/de active Application Filing

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