DE102004014163A1 - Polyols, are formed from linear polyesters by mixing the starting materials in a mixing or kneading reactor, with one or more horizontally rotating hollow shaft sections - Google Patents

Abstract

A process for producing polyols from linear polyesters such as polyethylene terephthalate, polybutylene terephthalate and/or their waste, oligoester condensates or compounds containing hydroxyl groups or aliphatic dicarbonic acids, comprises mixing polyethylene terephthalate and/or polyethylene terephthalate waste, an oligoester mixture and one or more glycols, alcohols or aliphatic dicarbonic acids in a mixing or kneading reactor. The reactor has one or more horizontally rotating hollow shaft sections. Special mixing elements are attached to the shafts. The linear polyester is PET waste. The arrangement used to produce the material consists of a horizontal reactor (1) with one or more hollow shafts (14) in an inner chamber (16), a drive (4), a dosing unit (2), and an extruder.

Description

The The invention relates to a process for the preparation of polyols linear polyesters such as polyetylene terephthalate, polybutylene terephthalate and / or Polyethylene terephthalate or Polybutylene terephthalate waste and an apparatus for carrying out this method according to the preambles the claims 1 and 15.

It Methods are known, according to which polyester waste by low molecular weight Glycols in solution and in this way polyester polyols for the production of rigid polyurethane foams, Polyisocyanurate foams; PUR adhesives or polyester adhesives be won. Similarly, methods are known, according to which polyester converted by glycols into oligoester diols and for the same Purpose to be used. Glycolysis is usually done with Oligoetherdiolen, e.g. Diethylene glycol or dipropylene glycol, performed. In addition, will the use of aminoalcohols, e.g. As diethanolamine or triethanolamine taught.

The EP 0 154 079 teaches a process for the preparation of Terephthalsäuresterpolyolen, in which PET waste is reacted with glycols and the ethylene glycol formed in the reaction is distilled off. Higher functional alcohols, eg N-methylglucoside, triethanolamine, diethanolamine or glycerol can be added to the reaction mixture.

According to another technical teaching according to the DE-OS 197 19 084 For example, polyester wastes and the oligoester condensates formed in the polyester synthesis are used to make polyester polyols. In J. Appl. Polym. Sci. 35, 775-785 (1988) describes the preparation of polyester polyols for polyurethanes from PET wastes by the reaction of the PET with glycols.

According to the teaching of DE-PS 199 15 125 Polyester-polymer polyols for polyurethanes are prepared from polyesters or polyester wastes with up to 20% by weight of these other contaminating polymers by reaction with oligoester condensates. In this case, homogeneous polymer polyols are obtained by reacting polyester waste with admixtures of up to 20% PVC, polystyrene, styrene copolymers such as ABS, SAN or ASA, polycarbonate, etc. with oligoester condensates, which are formed during the production of the polyester.

The used in this process Oligoesterkondensat is a hydroxyl and ester group-containing resin which is undesirable in polyester condensation By-product is created and currently has to be disposed of as waste. This Oligohydroxyester containing mixture is usually one at room temperature highly viscous to solid distillation product of polyester production, in which a proportion of organometallic compounds as residues of transesterification catalysts solved or dispersed.

As Polyesters are preferably polyethylene terephthalate wastes, e.g. Bottles from the DSD groupage, used up to 20 wt .-% other Plastic bottles, especially those made of PVC, polycarbonate, PEN and highly filled styrenic copolymers.

After the apprenticeship of DO-OS 199 18 650 Polyester alcohols with a wide viscosity range are obtained by transesterification using waste materials by reacting polyester waste with a hydroxyl and ester group-containing resin in the presence of the organometallic compounds contained therein at elevated temperature in a reaction step with polyethylene terephthalate and optionally glycols and aliphatic dicarboxylic acids. To control the properties of the polyester alcohols further glycols and / or triols or tetrols, di- and / or polycarboxylic acids or their anhydrides can be added to the reaction mixture. Furthermore, the reaction mixture for controlling the properties of the reaction product, and thus also the plastics produced therefrom, higher-functional alcohols, eg. As glycerol, trimethylolpropane, pentaerythritol and / or hexanetriol, are added with the aim of producing branched polyester alcohols.

After this method can be the viscosity of polyols based on linear polyesters, e.g. polyethylene terephthalate, significantly reduce the fact that during the reaction with glycols, transesterification or glycolysis, except glycols and / or oligoesters one opposite of terephthalic acid significantly lower molar amount of adipic acid or other aliphatic dicarboxylic acid or their anhydride added becomes.

The USP 5,981,672 and 6,048,907 relate to devices and methods for the preparation of polyester polyols by reaction of PET with a glycol. The devices have in common that the reactor vessel or the agitator shaft rotate around a horizontal axis. Both devices are for a batch Operation constructed.

For PBT or PEN have so far been known for no glycolysis process.

• – Reaktorwellen, die um horizontale Achsen rotieren,
• – auf den Reaktorwellen angebrachte Knetschaufeln, die einen linearen Versatz untereinander auf der Hohlwelle und zueinander bei der Anordnung von Mehrwellenraktoren aufweisen,
• – Volumenstrom des Reaktionsgutes ist über die Gesamtlänge des Reaktors unveränderlich,
• – Heizmantel ist durchgehend über die Gesamtlänge des Reaktors beheizbar,
• – durchgehend beheizbare Hohlwelle zur Beheizung der Kneterschaufeln und zur zentralen Wärmeabgabe an den Reaktorraum,
• – Reaktorraum ist nicht in definierte Einzugszone, Reaktionszone und Austragszone eingeteilt.

Regardless of the solvolysis of polyester wastes are discontinuous and continuous working devices for comminution, mixing and reaction of solid and liquid reaction components having the following characteristics:

• Reactor shafts rotating about horizontal axes
• - Kneading blades mounted on the reactor shafts, which have a linear offset with one another on the hollow shaft and with each other in the arrangement of multi-shaft tractors,
• - volume flow of the reaction mixture is unchangeable over the entire length of the reactor,
• - Heating jacket is continuously heated over the entire length of the reactor,
• Continuously heatable hollow shaft for heating the kneader blades and for central heat delivery to the reactor space,
• - Reactor space is not divided into defined feed zone, reaction zone and discharge zone.

Farther Devices are known in which the heat input takes place via the mixer blades and the mechanical influence on the reaction is of minor importance.

The known methods and devices is disadvantageously common, that they are discontinuous, i. batchwise in one or more Stages are operated and for an industrial continuous leadership of solvolysis of polyesters not are suitable because either too low throughputs are possible or unfavorable Reactor geometry high temperatures, increased pressure, expensive reactants or catalysts or because of successive reaction steps and optionally different reaction conditions a complex Multi-stage reaction technology are neces sary. Furthermore, the Drive is not bumpy and jerk-free, resulting in an increased Load the drive unit leads. A shift in the temperature profile in the reactor, due to the transport of the reaction mixture, is not defined influenceable. This makes it difficult for the the reaction suitable, optionally changing temperature conditions adjust.

Of the Invention is therefore the object of a method and a Apparatus for the production of polyols from linear polyesters, especially polyethylene terephthalate, PBT, PEN PET-G or polyethylene terephthalate, PBT, PEN or PET-G waste to develop without the mentioned disadvantages continuously under chemically specified process conditions the conditioning, the dosage and the reaction of the reaction mixture with the components supplied guaranteed.

According to the invention Problem solved by the features of claims 1 and 15.

So the process is characterized in that a mixture of polyethylene terephthalate and / or Polyethylene terephthalate wastes, an oligoester mixture, optionally one or more glycols, optionally others Alcohols and optionally one or more aliphatic dicarboxylic acids in a mixing / kneading reactor with one or more horizontally rotating Hollow shafts on which special mixing elements are arranged in one or more reaction and / or processing zones below continuous flow rate is reacted.

• – einen horizontal angeordneten Reaktor, der in einem Reaktorinnenraum eine oder mehrere Hohlwellen, die horizontal, parallel und rotierbar gelagert sind, aufweist, wobei der Reaktorinnenraum in Stoffflussrichtung in eine Misch- und Lösezone, eine Reaktionszone und eine Nachreaktions- und Austragszone geteilt ist,
• – ein mit einer Temperaturerfassung funktionell verbundenes Temperieraggregat, für einen Wärmeträgertransport in der oder die Hohlwellen und in Heizmantel(Misch- und Lösezone), Heizmantel(Reaktionszone) und Heizmantel(Nachreaktions- und Austragszone),
• – einen Antrieb der Hohlwellen,
• – eine mit der Misch- und Lösezone verbundene Förder- und Dosiereinrichtung und
• – eine mit der Nachreaktions- und Austragszone verbundene Austragseinheit.

The device according to the invention is characterized by

• A horizontally arranged reactor which has one or more hollow shafts which are mounted horizontally, parallel and rotatable in a reactor interior, the reactor interior being divided in the material flow direction into a mixing and dissolving zone, a reaction zone and a post-reaction and discharge zone,
• A temperature control unit functionally connected to a temperature control unit, for a heat carrier transport in or the hollow shafts and in the heating jacket (mixing and dissolving zone), heating jacket (reaction zone) and heating jacket (post-reaction and discharge zone),
• A drive of the hollow shafts,
• A conveying and metering device connected to the mixing and dissolving zone and
• A discharge unit connected to the post-reaction and discharge zone.

A Embodiment of the invention is characterized in that the Hollow shafts on their surface Kneading and stirring elements arranged so that their surfaces with a reactor jacket (inside) and / or with the surfaces the kneading and stirring elements adjacent hollow shafts in the rotation is steadily narrowing and again opening column form.

In a further embodiment of the invention, the conveyor and Metering device of the device a liquid metering with reservoir and Dosing pump and a solids feed on.

In a further development, the hollow shafts on its surface kneading and stirring elements arranged so that their surfaces with a reactor shell (inside) and / or with the surfaces of the kneading and stirring elements of adjacent hollow shafts during rotation continuously narrowing and re-opening gaps form , and that the reactor at the Dosiersei te starting from the discharge side continuing a mixing and dissolving zone, a reaction zone and a Nachreaktions- and discharge zone.

• • Füllen des Reaktors mit der/den Glykol-Komponente/n mit der entsprechenden Pumpe bei ausgeschalteter Produktpumpe
• • Füllen des Reaktors mit der aufgeschmolzenen Oligoester-Komponente mit der entsprechenden Pumpe (Behälter, Pumpe und Leitungen beheizt) bei ausgeschalteter Produktpumpe
• • Einschalten von Rührer und Heizung des Reaktors und der Wellen
• • Zudosieren der entsprechenden Menge PET-Flakes über eine Schnecke
• • Batchbetrieb des Reaktors für beispielsweise 60 min bei beispielsweise 240 °C in der Reaktionszone; PET wird durch Umesterung und Spaltung der Polymerketten in Polyol überführt
• • Übergang zum kontinuierlichen Betrieb durch gleichzeitiges Einschalten der Zuführungspumpen für Reaktionskomponenten und der Produktpumpe
• • der kontinuierliche Betrieb kann prinzipiell unbegrenzte Zeit dauern; die Reaktion PET → Polyol wird dabei fortgesetzt
• • bei der Umesterung wird Ethylenglykol freigesetzt, das über die Kolonne abdestilliert und aufgefangen wird
• • die Temperaturen in den drei Zonen des Reaktors können unterschiedlich sein
• • zum Herunterfahren Abschalten der Reaktionskomponenten- und Produkt-Pumpen; dadurch wird die letzte „Portion" der Reaktionsmischung noch für die Dauer von Lösen, Reaktion und Nachreaktion im Reaktor gehalten
• • nach beispielsweise 60 min Batchbetrieb Leerfahren des Reaktors durch Einschalten der Produkt-Pumpe, gleichzeitig Abschalten der Heizung
• • alle Operationen unter Schutzgasatmosphäre (z. B. Stickstoff) zur Verhinderung der durch die Einwirkung von Sauerstoff verursachten Qualitätsminderung der Polyole

The essential process steps in the PET glycolysis according to the invention are:

• • Fill the reactor with the glycol component (s) with the corresponding pump with the product pump switched off
• • Fill the reactor with the melted oligoester component with the corresponding pump (tank, pump and lines heated) with the product pump switched off
• • Switching on of stirrer and heating of the reactor and the waves
• • Add the appropriate amount of PET flakes via a screw
• Batch operation of the reactor for, for example, 60 minutes at, for example, 240 ° C in the reaction zone; PET is converted into polyol by transesterification and cleavage of the polymer chains
• • Transition to continuous operation by simultaneously switching on the reaction component feed pumps and the product pump
• • the continuous operation can in principle last indefinitely; the reaction PET → polyol is continued
• In the transesterification, ethylene glycol is released, which is distilled off via the column and collected
• • The temperatures in the three zones of the reactor can be different
• • Shutdown Shutdown of reaction component and product pumps; This keeps the last "portion" of the reaction mixture in the reactor for the duration of dissolution, reaction and after-reaction
• • after, for example, 60 minutes of batch operation, empty the reactor by switching on the product pump and at the same time switching off the heating
• • All operations under a protective gas atmosphere (eg nitrogen) to prevent degradation of the polyols due to the action of oxygen

The Mixing of components, mechanical comminution of the linear Polyester and the chemical reaction is in a single or multi-shaft mixing / kneading reactor executed in which one or more hollow shafts rotate substantially horizontally and so the reaction mixture by suitable kneading elements or blades mix intensively, liquefy at temperatures of 160 to 280 ° C and through one or more reaction zones in the direction of the discharge transport. The liquid ones and the solid components are separated into the heated chamber or the heated chambers of the reactor out. Surprisingly, it was found that this arrangement faces a discontinuous operation significantly lower residence times allows. After a mean residence time of 10 to 1000 minutes, in particular 20 to 600 minutes, passes the substantially liquid precursor in another part of the reaction chamber where the reaction is optional under changed temperature and time conditions is completed. Optionally, in another chamber volatiles removed by distillation.

• 1. Dosiereinrichtungen für die Reaktionskomponenten (Polyester-Granulat, z.B. Polyethylenterephthalat-Granulat, Oligoesterkondensat, gegebenenfalls ein oder mehrere Glykole, gegebenenfalls eine oder mehrere aliphatische Dicarbonsäuren),
• 2. einem Reaktor mit Eintragzone, Zerkleinerungs-, Löse- und Mischzone, Haupt- und gegebenenfalls Nachreaktionszone und Austragszone,
• 3. ggf. einer integrierten Vorrichtung zur Destillation unter vermindertem Druck,
• 4. einer Austrags- und ggf. Filtrationseinrichtung (zur Abtrennung von Fremdkörpern wie Sand, Metallteilen u.a. nicht umsetzbare Polymer-Beimengungen wie z. B. PVC oder Polystyren können als Dispersion erhalten bleiben) für das Produkt
• 5. einem Heizaggregat,
• 6. einer Steuerungseinheit.

The device according to the invention consists of the following parts:

• 1. metering devices for the reaction components (polyester granules, eg polyethylene terephthalate granules, oligoester condensate, optionally one or more glycols, optionally one or more aliphatic dicarboxylic acids),
• 2. a reactor with entry zone, crushing, dissolving and mixing zone, main and, where appropriate, post-reaction zone and discharge zone,
• 3. optionally an integrated distillation apparatus under reduced pressure,
• 4. a discharge and possibly filtration device (for the separation of foreign bodies such as sand, metal parts, inter alia, unreachable polymer admixtures such as PVC or polystyrene can be retained as a dispersion) for the product
• 5. a heating unit,
• 6. a control unit.

The Dosing devices for the solids are to be promoted to the properties of Components adapted. Further metering units serve to convey the liquid reaction components. The material flows are measured by a measuring and control system with respect to the mass ratio of each other and in terms the total mass matched to the required residence time in the reactor. One or more streams can preheated his. This may be the waste heat of the reactor can be used.

In the reactor are one or more identical or opposite directions substantially around horizontal axes rotating hollow shafts. The hollow shafts of the reactor have kneading and stirring elements. The arrangement of the kneading and stirring elements on the hollow shaft or the hollow shafts and their position follow in a preferred embodiment of a technical curve, for. B. a sinusoid, involute or rolling curve. In a preferred embodiment, the shafts rotate at different speeds. The inner walls of the reactor can be provided with internals (baffles) into which the kneading and stirring elements engage during operation in such a way that during operation one revolution of the hollow shaft involves one or more narrowing gaps Abrißkanten arise. In a preferred embodiment, the hollow shafts have a diameter increasing in stages in the direction of the flow of the reaction mixture.

On the transitions between the reactor zones is in a preferred embodiment each a controlled rotary valve, the reaction in the bottom Area of the filling each to the next Promotes reactor zone.

The reactor housing consists in an advantageous development of two half-shells, the one disassembly to cleaning and Allow maintenance.

The Heating device for generating the required reaction temperature in the reactor can in the hollow hollow shafts and / or in the casing be accommodated and z. B. by an indirect flow with to the desired Temperature-controlled heat transfer medium, e.g. thermal oil respectively. The inflow of the heat carrier in the hollow shaft or the hollow shafts takes place in a preferred embodiment essentially tangential. The heating jacket of the reactor is in one preferred embodiment separated into several areas.

At the End of the reactor are an overflow, a Filtration device, preferably a column filter with backwashing, and a vacuum pump attached.

The if necessary, distillation zone, either in the reactor integrated or as a separate unit, optionally used for distillative removal of volatile By-products, optionally with the use of vacuum, wherein the applied pressure 0.1 to 400 mbar, preferably 5 to 100 mbar, can amount.

at Use of a vacuum distillation stage is between the kneading, mixing and reaction zone and the distillation step and between the Distillation and the discharge zone each a smuggling for example about a gear lock, a discontinuous stuffing system, a continuous pressure system, a valve or a bellows system or by the execution the kneading and stirring elements, which allow a temporary seal of this compartment and as Valve only a certain amount of reaction mixture in the following Allow compartment to enter, optionally for retention of foreign bodies with downstream filter provided. The downstream filter is preferably designed as a column filter with backwashing.

• – kontinuierliches Verfahren mit einer Verfahrensstufe,
• – keine Rückvermischung,
• – Verwendung von preisgünstigen Einsatzstoffen,
• – Umsetzung bei relativ niedrigen Temperaturen,
• – eindeutig handhabbares Temperaturprofil in allen Reaktorzonen einschließlich definierten Reaktionsabbruchs durch definierte Beeinflussung des Temperaturprofils in den einzelnen Reaktorzonen und Ausgleich der Verschiebung des Temperaturprofils, welches durch den axialen Transport des aufgeheizten Reaktionsgutes entsteht,
• – im wesentlichen drucklose Arbeitsweise,
• – schneller axialer Materialtransport in der Einzugzone vom Füllstutzen in Richtung Reaktionszone mit gleichzeitiger inniger Vermischung,
• – unterschiedlicher Volumenstrom in den Zonen möglich,
• – auf den Prozeß einstellbare, kurze Verweilzeiten, d. h. hoher Materialdurchsatz,
• – Reduzierung der eingesetzten Glykol- und Aminmengen,
• – energie- und investitionssparend arbeitender Prozeß,
• – geringer Lufteintrag durch die Knet-Mischbarren in das Reaktinsgut,
• – Betrieb ohne zusätzliches Schutzgas,
• – unmittelbare Benetzung der eingetragenen Schaummaterialien unter gleichzeitiger Entspannung des vorher komprimierten Materials und Auffüllung des vorhergehenden Gasraumes mit dem flüssigen Reaktionsgut,
• – deutlich besserer Wärmeübergang durch die Oberflächenvergrößerung bei Dekompression, dadurch große Kontaktfläche der chemischen Reaktionspartner unmittelbar nach dem Materialeintrag,
• – Produkt mit geringem Gehalt an unerwünschten primären aromatischen Aminen,
• – Produkt ohne Aufarbeitung verwendbar.

The reaction procedure in the reactor according to the invention has made possible a process with the following advantages:

• Continuous process with a process step,
• - no backmixing,
• Use of low-cost starting materials,
• Reaction at relatively low temperatures,
• - clearly manageable temperature profile in all reactor zones including defined reaction termination by defined influence of the temperature profile in the individual reactor zones and compensation of the shift of the temperature profile, which results from the axial transport of the heated reaction material,
• Essentially non-pressurized operation,
• - faster axial transport of material in the feed zone from the filler neck in the direction of the reaction zone with simultaneous intimate mixing,
• - different volume flow in the zones possible,
• - process-adjustable, short residence times, ie high material throughput,
• - Reduction of the amount of glycol and amine used,
• - Energy and investment saving process,
• Low air entry through the kneading mixing bars into the reactant material,
• - operation without additional inert gas,
• Direct wetting of the registered foam materials with simultaneous relaxation of the previously compressed material and filling of the preceding gas space with the liquid reaction product,
• - significantly better heat transfer due to the surface enlargement during decompression, thus large contact surface of the chemical reactants immediately after the material entry,
• A product with a low content of unwanted primary aromatic amines,
• - Product usable without work-up.

The produced according to the invention Polyester alcohols are directly in after completion of the transesterification Storage or storage containers bottled without further work-up. The essential product data are the hydroxyl number (OH) and the Viscosity. The inventive method allows it, depending on the embodiment linear and branched polyester alcohols having hydroxyl numbers of 60 to 600, viscosities (at 20 ° C) from 1200 to 500,000 mPas and high aromatics content. That's what they can do in particular for the production of high-quality or flame-retardant polyurethanes be used.

Furthermore, the polyester alcohols according to the invention are advantageously used for the production of rigid polyisocyanurate foams. In addition, by incorporation of unsaturated Dicarboxylic acids (maleic acid, fumaric acid) or their anhydrides unsaturated polyester alcohols are prepared, which can be advantageously used in the production of paints, coatings and adhesives.

The according to the inventive method produced polyols are characterized by a high stability in the Storage and good miscibility with the additives in polyurethane systems out. Cause for these desirable ones Good properties is the by the inventive method The production achieved broad molecular weight distribution of both the terephthalate esters itself as well as arranged in them alkylene glycol. While the degree of polymerization of PET is in the order of 90 to 100, is that of Oligohydroxyester at 2 to 4. By transesterification with the help of organometallic compounds contained in the oligohydroxy esters Catalyst residues is due to the alkylene glycols present in it a rapid chain scission on the ester groups and thereby one Reduction of the degree of polymerization causes. Because these transesterification reactions Equilibrium reactions are, the chain cleavage takes place according to statistical Laws. The oligohydroxyesters do not achieve higher degrees of polymerization, but remain as relatively low molecular weight polyester polyols in a mixture. The degrees of polymerization achieved by the transesterification of the PET can reach values between 40 and 5, giving a broad molecular weight distribution achieved, which is confirmed by gel permeation chromatography. The combination of broad molecular weight distribution and installation of a Alkylenglykolgemisches in the polymer chains, thereby replacing the short-chain ethylene glycol by higher homologues, leads to the desired, properties of the invention, the by a direct depolymerization by transesterification with only one Glycol neither from the Oligohydroxyestern still obtained from the PET can be because in these cases Products of a completely different molar composition and molecular weight distribution arise, which are still crystallizable and therefore not stable are.

• 1. lineare Polyester, beispielsweise Polyethylenterephthalat, Polybutylenterephtalat, Abfälle von linearen Polyestern, die mit bis zu 20 % PVC, Polystyren, Styren-Copolymeren wie ABS, SAN oder ASA, Polycarbonat usw. verunreinigt sein können,
• 2. Glykole wie Ethylenglykol und seine Oligomeren, vor allem Diethylenglykol, Triethylenglykol, Tetraethylenglykol, Polyethylenglykole der mittleren Molmassen 200, 300, 400, 600, 800, 1000; Propylenglykol, Dipropylenglykol, Tripropylenglykol, Tetrapropylenglykol, Polypropylenglykole der mittleren Molmassen 200, 300, 400, 600, 800, 1000, Butandiol-1,4, Polybutylenglykole der mittleren Molmassen zwischen 200 und 1000 und Hexandiol-1,6,
• 3. Oligoester der Zusammensetzung 40 – 80% Terephthalsäure, 5 – 30% gebundenes Ethylenglykol, 1 – 20% freies Ethylenglykol, 1 – 20% gebundenes Diethylenglykol, 1 – 15% freies Diethylenglykol, 0 – 10% längerkettige Ethylenglykole, 0,5 – 5% metallorganische Verbindungen,
• 4. aliphatische bzw. cycloaliphatische Carbonsäuren oder Dicarbonsäuren wie Adipinsäure, Azelainsäure, Sebacinsäure, Cyclohexandicarbonsäure oder Maleinsäure oder, soweit diese existieren, deren Anhydride.

As starting materials are used:

• 1. linear polyesters, for example polyethylene terephthalate, polybutylene terephthalate, waste of linear polyesters, which may be contaminated with up to 20% PVC, polystyrene, styrene copolymers such as ABS, SAN or ASA, polycarbonate etc.,
• 2. glycols such as ethylene glycol and its oligomers, especially diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycols of average molecular weights 200, 300, 400, 600, 800, 1000; Propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycols of average molecular weights 200, 300, 400, 600, 800, 1000, 1,4-butanediol, polybutylene glycols of average molecular weights between 200 and 1000 and 1,6-hexanediol,
• 3. Oligoester of composition 40-80% terephthalic acid, 5-30% bound ethylene glycol, 1-20% free ethylene glycol, 1-20% bound diethylene glycol, 1-15% free diethylene glycol, 0-10% longer-chain ethylene glycols, 0.5- 5% organometallic compounds,
• 4. aliphatic or cycloaliphatic carboxylic acids or dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, cyclohexanedicarboxylic acid or maleic acid or, if these exist, their anhydrides.

The The invention will be explained in more detail with reference to drawings and exemplary embodiments.

It demonstrate

1 a schematic representation of the device according to the invention at a glance,

2a a schematic representation of a reactor with a hollow shaft in longitudinal section without stall edge and without gas inlet capillary,

2 B a schematic representation of a reactor with a hollow shaft in longitudinal section with stall edge and with gas inlet capillary,

3a a schematic representation of a reactor with two hollow shafts in longitudinal section without stall edge and without Gaseinlasskapillare,

3b a schematic representation of a reactor with two hollow shafts in longitudinal section with stall edge and with gas inlet capillary,

4 a schematic representation of the cross section AA of 3b a reactor with two hollow shafts,

5a a schematic detail of a supply connection for the supply of the heating medium in the hollow shaft,

5b a schematic sectional view of the preceding detail,

6a a schematic cross-sectional view AA of 2a and 2 B a reactor with a hollow shaft,

6b a schematic sectional view AA of 3a and BB of 3b a reactor with two hollow shafts of equal size,

6c 1 is a schematic representation of a reactor with two hollow shafts, which have a different diameter,

6d a schematic sectional view of a reactor with three equal-sized hollow shafts,

7 a schematic representation of a metering extruder,

8a a schematic representation of a rotary valve with adjustable passage cross-section as a detail of the reactor,

8b a schematic representation of a rotary valve with adjustable passage cross-section in a reactor with two hollow shafts in a sectional view,

8c a schematic representation of a rotary valve with non-adjustable flow area as a detail of the reactor and

8d a schematic representation of a rotary valve with non-adjustable flow area in a reactor with two hollow shafts in a sectional view.

1 shows that in a reactor 1 consisting of a horinzontal arranged reactor housing 11 consists of one or more hollow shafts 14 are arranged. At the front ends 121 of the reactor 1 There are bearings that have one or two hollow shafts 14 axially fix and absorb the radial forces in the operating state. The reactor housing 11 has a cylindrical cross-section in the case of single-shaft reactors and an eight-shaped cross section in the case of twin-shaft reactors.

The number of kneading and stirring elements 145 respectively. 150 on the individual carrier discs 144 respectively. 149 the individual waves 141 respectively. 146 must always be different from each other to prevent the passage of the kneading and stirring elements 145 / 150 the individual waves 141 / 146 with each other, the increase of the required torque remains limited. The moment of resistance results from the viscosity of the reaction material at the corresponding reactor location and in the gap between kneading and stirring 145 / 150 and corresponding corrugated sheath 142 / 147 and at this point corresponding kneading and stirring elements 145 / 150 with each other resulting plug flow.

The reactor housing is divided longitudinally into three areas. On the heating jacket for the mixing and dissolving zone 111 are the filler neck 114 and 116 that connects to the reaction space 16 realized.

In the area of the heating jacket (mixing and dissolving zone) 118 is an extruder connection 115 arranged ( 7 . 8a . 8c ), the connection between the reaction space 16 and a metering extruder 25 realized. The extruder connection 115 is on the reactor housing 11 arranged in such a way that it passes through the heating jacket (mixing and dissolving zone) 118 in the area of the cleaning and intake shaft 146 are passed in the manner that the respective longer generatrix tangent to the reactor line on the inside of the reaction space 16 reached. The shorter generatrix of the extruder connection 115 reaches the reaction space 16 below the liquid level of the reaction mixture.

According to 2 and 3 the heating jacket (reaction zone) 119 on the inside to the reaction room 16 , in the work area of the kneading and stirring elements (kneading and stirring shaft) 145 , Shell installations 123 on. Between the shell installations 123 and the kneading and stirring elements (kneading and stirring shaft) 145 is an assignment in such a way that the outer diameter of the circle of the kneading and stirring elements (kneading and stirring shaft) 145 along with those on the inside of the jacket to the reaction space 16 tangentially arranged shell internals 123 form a constantly narrowing in the direction of work gap, the sudden by a sharp-edged flow separation edge 124 is ended ( 4 ). Below the stall edge 124 are gas inlet capillaries 125 arranged, which are used for the inlet of inert gas or active gas. In the area of the cleaning and intake shaft 146 that is in the area of the reaction zone 112 are stationary, kneading and stirring elements 126 arranged in such a way that they are separated by the kneading and stirring elements (cleaning and intake shaft) 150 penetrate generated rotation lines in the vacant places.

The discharge nozzle 117 ( 1 . 2 . 3 ) is due to the heating jacket (post-reaction and discharge zone) 120 at the bottom to the reaction room 16 passed and is located directly on the front side of the heating mantle (post-reaction and discharge zone) 120 ,

The kneading and stirring shaft 141 and the cleaning and intake shaft 146 are each at the inputs and outputs with fixed connections 15 Provided. On the discharge side are the flow connections 151 and at the entry side, the return ports 152 , ie, the temperature of the waves takes place counter to the working direction. The flow velocity of the heat transfer medium in the hollow shafts 14 slows down due to the structural design of the bearing shaft (kneading and stirring shaft) 143 or the bearing shaft (cleaning and intake shaft) 148 by different volumes in the individual zones 111 . 112 and 113 from the delivery side to the entry page. The individual zones of the reactor housing 11 are individually tempered by the flow mixing and dissolving zone 153 to the return mixing and dissolving zone 154 , from the flow reaction zone 155 to the return reaction zone 156 and from the supply line post-reaction and discharge zone 157 to the return post-reaction and discharge zone 158 , ie, the temperature is controlled zone by zone against the working direction of the reactor 1 with uniform flow rate of the heat transfer medium.

The kneading and stirring shaft 141 is made of a shaft sheath (kneading and stirring shaft) 142 and a bearing shaft arranged on the same center line (kneading and stirring shaft) 143 educated. The diameter of the bearing shaft (kneading and stirring shaft) 143 rises from the beginning of the heating mantle (mixing and dissolving zone) 118 over the area of the heating jacket (reaction zone) 119 until the end of the heating jacket (post-reaction and discharge zone) 120 steady or extended at the transition points from one zone to another to a larger diameter. On the continuous shaft sheath (kneading and stirring shaft) 142 are stationary carrier discs (kneading and stirring shaft) 144 appropriate. The carrier discs (kneading and stirring shaft) 144 have a defined radial offset to each other. At the circumference of the individual carrier discs (kneading and stirring shaft) 144 are several kneading and stirring elements (kneading and stirring shaft) 145 arranged in such a way that during the rotation of the kneading and stirring shaft 141 both on the individual carrier disc (kneading and stirring shaft) 144 as well as in association with all carrier discs (kneading and stirring shaft) 144 form a common circle diameter.

The arrangement of the carrier discs (kneading and stirring shaft) 144 with the kneading and stirring elements (kneading and stirring shaft) 145 takes place opposite the center line of the kneading and stirring shaft 141 in such a way that depending on the number of kneading and stirring elements (kneading and stirring shaft) 145 on the circumference of the hollow shaft 14 Form multi-start helices ( 3 ). Notwithstanding the helices are the individual kneading and stirring elements (kneading and stirring shaft) 145 arranged in such a way that they are from the beginning of the area heating mantle (mixing and dissolving zone) 118 up to the geometric center of the heating jacket (reaction zone) 119 leading the assigned helix. From the geometric center of the heating jacket (reaction zone) 119 until the end of the heating jacket (post-reaction and discharge zone) 120 are the kneading and stirring elements (kneading and stirring shaft) 145 arranged lagging relative to the associated helix. The defined assignment of the leading and trailing of the kneading and stirring elements (kneading and stirring shaft) 145 is achieved by a different linear offset, which consist of individual lines starting with the helix, intersecting them again in the geometric center of the reaction zone and then forming a common point at the end point with the helix. The offset can also by technical or mathematical curves, z. B. sinoids with the same points of the beginning, the crossing of the helix and the end of the helix as previously described can be realized. Radially, the helices are designed so that the end points always coincide with a starting point of a helix of the multi-speed system from the center line of the kneading and stirring shaft and thus form continuously extending helices.

The cleaning and intake shaft 146 ( 3 ) has the same basic structure as the kneading and stirring shaft 141 , It consists of the shaft jacket (cleaning and intake shaft) 147 with the bearing shaft arranged on the same center line (cleaning and intake shaft) 148 , On the shaft jacket (cleaning and intake shaft) 147 are carrier discs (cleaning and intake shaft) 149 stationarily arranged in such a way that they are in contact with the kneading and stirring elements (cleaning and draw-in shaft) mounted on them 150 in the assembled state of the reactor 1 the free spaces of the corresponding carrier discs (kneading and stirring shaft) 144 with the kneading and stirring elements attached to it (kneading and stirring shaft) 145 with a uniform in the middle position of both waves gap fill each other.

In the area of the heating jacket (mixing and dissolving zone) 118 form the edges of the kneading and stirring elements (kneading and stirring shaft) 145 and the edges of the kneading and stirring elements (cleaning and draw-in shaft) 150 through pointed wedge angle ( 6a to 6d ) in the direction of rotation a cutting line. In the area of the heating jacket (reaction zone) 119 and the heating jacket (post-reaction and discharge zone) 120 is defined by blunt wedge angles ( 4 . 6b to 6d ) of the kneading and stirring elements (kneading and stirring shaft) 145 and the kneading and stirring elements (cleaning and intake shaft) 150 in the direction of rotation a pressure surface to each other and to the shell internals in the reactor space 16 , or in the case of single-shaft reactors to the stationary kneading and stirring elements 126 generated.

The conveying and metering device 2 ( 1 ) consists of compressible and solid reaction components from the metering extruder 25 that's about the extruder port 115 with the reaction space 16 connected is. The extruder screw 252 has a steadily decreasing free volume in the working direction, which is achieved by a steady increase in extruder screw core and by a steady reduction in extruder screw pitch. At the metering extruder jacket is a preheat device 251 in the immediate vicinity of the heating jacket (mixing and dissolving zone) 118 arranged.

The metering of liquids takes place via the liquid metering 26 consisting of each liquid component of a metering pump 262 that communicate with the reaction space 16 in the area of the heating jacket (mixing and dissolving zone) 118 connected, and a storage container 261 connected to the input of the dosing pump 262 connected is ( 1 ).

The dosage of melts takes place via the melt dosage 27 coming from a heated metering pump 272 that communicate with the reaction space 16 in the area of the heating jacket (mixing and dissolving zone) 118 connected, and a heated storage tank 271 connected to the input of the dosing pump 272 connected is ( 1 ).

In the area of the post-reaction and discharge zone 113 is a distillation column 7 with the reaction space 16 connected.

At the entrance and exit of the reaction zone 112 ( 8a to 8d ) is in each case a rotary valve system 127 arranged. The rotary valve system 127 consists of a stationary chamber disc 128 facing the reactor jacket (inside) 122 is sealed. On the chamber disc 128 there is an angle adjustable adjusting disc 129 which has one or more apertures together with the chamber disc 128 releases in different cross sections. On the hollow shafts 14 there are rotor disks 130 with each revolution of the hollow shafts 14 impulsively the set cross sections on the chamber disc 128 and adjusting disc 129 release. This arrangement has the consequence that at free cross section of the rotary valve system 127 at the transition from the mixing and dissolving zone 111 to the reaction zone 112 and at free cross section of the rotary valve system 127 at the transition to the post-reaction and discharge zone 113 the entire system can be run in continuous operation. By reducing the free cross-section of the rotary valve system at the transition from the mixing and dissolving zone 111 to the reaction zone 112 and with free passage of the rotary valve system 127 from the reaction zone 112 to the post-reaction and discharge zone 113 is in the reaction zone 112 and post-reaction and discharge zone 113 during operation of the suction pump 64 generates a pulsating negative pressure. By free passage at the transition from the mixing and dissolving zone 111 to the reaction zone 112 and with reduced passage through the rotary vane system 127 from the reaction zone 112 to the post-reaction and discharge zone 113 is in the reaction zone 112 and post-reaction and discharge zone 113 during operation of the conveying and metering device 2 an overpressure in the reaction zone 112 generated. A quasi-batch operation is possible if the rotary valve system 127 temporarily mutually opened and closed.

The temperature detection 3 by a at the transition point of the heating mantle (mixing and dissolving zone) 118 to the heating jacket (reaction zone) 119 arranged temperature sensors (mixing and dissolving zone) 32 , by a temperature sensor (reaction zone) 33 in the geometric center of the reaction space 15 and a temperature sensor (post-reaction and discharge zone) 34 at the transition point of the heating jacket (reaction zone) 119 to the heating jacket (post-reaction and discharge zone) 120 , The temperature sensors 32 . 33 and 34 are with the display part 31 connected.

The drive of the kneading and stirring shaft 141 and the cleaning and intake shaft 146 takes place preferably via a hydraulic motor 4 ,

The temperature of the heating jacket (mixing and dissolving zone) 118 , the heating jacket (reaction zone) 119 , the heating jacket (post-reaction and discharge zone) 120 as well as the wave mantle (kneading and stirring shaft) 142 and the shaft jacket (cleaning and intake shaft) 147 done by a tempering unit 5 , The connections from the temperature control unit 5 to the individual heating jackets of the zones and the Wellenheizmänteln are arranged in such a way that the flow direction of the heating medium always in the opposite direction to the working direction of the reaction mixture in the reaction space 16 he follows.

The discharge unit 6 is behind the discharge nozzle 117 arranged and is from an overflow device 61 , a filter unit 62 and a downstream suction pump 64 educated. Above the filter unit 62 is from the filter input 621 to the filter output 622 a differential pressure gauge 63 Switched, which indicates the condition of the filter candle 623 signaled.

operation the device according to the invention

The solid reaction product, for example PET flakes, can be passed through a metering extruder 25 in the reaction space 16 over the extruder connection 115 in the area of the heating jacket (mixing and dissolving zone) 118 below the liquid level in the reaction space 16 be introduced.

The solid reaction mixture is by the on the cleaning and feed shaft 146 located kneading and stirring elements (cleaning and intake shaft) 150 in the area of the heating jacket (mixing and dissolving zone) 118 tangential to the reaction space 16 moved in. The kneading and stirring elements (cleaning and intake shaft) 150 and the kneading and stirring elements (kneading and stirring shaft) 145 have in the area of the heating jacket (mixing and dissolving zone) 118 acute angle at the edges lone wedge angle, which form cutting lines in the middle passage of the kneading and stirring elements. The reaction material is cut in this area and together with components from the liquid metering 26 and the melt dosage 27 , which are introduced into this area, mixed and dissolved under application of heat. The liquid dosage 26 via speed-controlled pumps 262 containing liquids from storage containers 261 suck in and the reaction space 16 respectively. The melt dosage 27 via speed-controlled, heated pumps 272 that melt from the heated storage tank 271 suck in and the reaction space 16 respectively. Due to the right-handed arrangement of the kneading and stirring elements (kneading and stirring shaft) 145 and the left-handed arrangement of the kneading and stirring elements (cleaning and draw-in shaft) 150 in multi-course helical rows, the arrangement of the kneading and stirring elements (kneading and stirring shaft) 145 and the kneading and stirring elements (cleaning and intake shaft) 150 the respective helical line in the area of the heating jacket (mixing and dissolving zone) 118 leading and thus a steeper angle to the working direction in the reaction chamber 16 is formed between the kneading and stirring elements (kneading and stirring shaft) 145 on the kneading and stirring shaft 141 and the kneading and stirring elements (cleaning and intake shaft) 150 a clear assignment in the middle position of the waves given by the different speeds of the kneading and stirring shaft 141 and the cleaning and intake shaft 146 is realized. This arrangement has a rapid removal of the reaction material from the filler neck 114 and the extruder connection 115 result. In the area of the heating jacket (reaction zone) 119 is the arrangement of the kneading and stirring elements (kneading and stirring shaft) 145 and the kneading and stirring elements (cleaning and intake shaft) 150 by lagging the respective helix flatter, resulting in a longer residence of the reaction material in the reaction chamber 16 in the area of the heating jacket (reaction zone) 112 causes. The edges of the kneading and stirring elements (kneading and stirring shaft) 145 and the kneading and stirring elements (cleaning and intake shaft) 150 have an obtuse-angled wedge angle and form one another in the region of the central passage and to the shell internals (reactor space) 123 Pressure surfaces, which overburden the reaction material beyond the breaking stress and thereby dissolve the material mixture. The wedge-shaped jacket internals 123 with the stall edge 124 cause the formation of high speed micro vortices behind the stall edge 124 , which also leads to the formation of gas bubbles with very low internal pressure, which implode in the sequence. The space between the stall edge 124 and the reactor jacket (inside) 122 is ideal for the introduction of an active gas or shielding gas through geometrically determined gas inlet capillaries 125 , In the area of the heating jacket (post-reaction and discharge zone) 120 is the arrangement of the kneading and stirring elements (kneading and stirring shaft) 145 and the kneading and stirring elements (cleaning and intake shaft) 150 again leading to the respective helical line and thus forms a steep angle to the discharge nozzle 117 out. The kneading and stirring shaft 141 and the cleaning and intake shaft 146 rotate as a function of the number of rows of kneading and Rührele elements on the waves at different speeds to each other. The different speeds cause a relative movement of the kneading and stirring elements (kneading and stirring shaft) 145 and the kneading and stirring elements (cleaning and intake shaft) 150 to each other, which has a plaster effect. Temperature measurement at the transition of the heating jacket (mixing and dissolving zone) 118 to the heating jacket (reaction zone) 119 , in the middle of the reaction space 15 and at the transition of the heating jacket (reaction zone) 119 to the heating jacket (post-reaction and discharge zone) 120 is done via thermocouples whose thermoelectric voltages are displayed and are available for further control operations as an input signal.

By-products of the chemical reaction in the reactor 1 that at the temperature in the reaction space 16 go into the vapor phase, are in the distillation column 7 condensed and outside the reactor 1 collected. If necessary, by the vacuum pump 64 in the reaction room 16 a vacuum can be made to accelerate the distilling off. With the help of the rotary valve system 127 the application of the negative pressure can be controlled.

Behind the discharge nozzle 117 is the delivery unit 6 arranged. This will be from an overflow device 61 , one or more downstream filter units 62 and a downstream suction pump 64 educated. Above the filter unit 62 is between the filter input 621 and filter output 622 a differential pressure gauge 63 switching the condition of the filter cartridge (s) 623 indicating and brings to display or control technology, the product flow switches to a parallel filter unit.

example 1

In a reactor according to the invention with a total volume of 20 l 2.5 kg Oligoesterkondensat are melted according to claim 5 at 100 ° C in the reservoir, conveyed through a heated pump and heated pipes in the reactor and heated there to 210 ° C. After switching on the kneading stirrers, 6.7 kg of PET waste (91.2% PET, 4.7% PVC, 3.3% HDPE, 0.8% PS) are removed within 5 minutes via a metering screw fed. After 15 minutes, it is heated to 245-250 ° C, and molten oligoester condensate and PET waste are continuously fed at rates of 13.5 and 36.2 kg per hour, respectively. After leaving the reaction zone, the mixture is transferred to a degassing zone in which a reduced pressure of 110 mbar is set at a temperature of 160.degree. About the suction line and a distillation column a by-product stream of 13.3 kg / h is withdrawn, which consists essentially of ethylene glycol and diethylene glycol. After 30 minutes, the removal of a product stream of about 50 kg per hour is started, which is filtered. Samples are taken at intervals of 30 minutes. This gives a substantially constant product with a viscosity η ²⁵ of 12,500 and an OH number of 310 mg KOH / g.

Example 2

In a reactor according to the invention as in Example 1, 3.83 kg of molten oligoester condensate according to claim 5 and 1.88 kg of diethylene glycol are conveyed via a heated pump and heated pipes into the reactor and heated there to 200 ° C. After switching on the kneading stirrer, 3.54 kg of PET waste (97% PET) are fed in within 5 minutes via a metering screw. After 15 minutes, the mixture is heated to 215 to 220 ° C, and molten oligoester condensate, diethylene glycol and PET waste are continuously fed at delivery rates of 19.5, 9.5 and 17.7 kg per hour, respectively. After leaving the reaction zone, the mixture is transferred to a degassing zone in which a reduced pressure of 110 mbar is set at a temperature of 160.degree. About the suction line and a distillation column a by-product stream of 10.2 kg / h is withdrawn, which consists essentially of ethylene glycol and diethylene glycol. After 30 minutes, the removal of a product stream of about 50 kg per hour is started, which is filtered. Samples are taken at intervals of 30 minutes. A substantially constant product having a viscosity η ²⁵ of 11,500 and an OH number of 325 mg KOH / g is obtained.

Example 3

In a reactor according to the invention as in Example 1 5.0 kg Oligoesterkondensat are melted according to claim 5 at 100 ° C in the reservoir, conveyed through a heated pump and heated pipes in the reactor and heated there to 200 ° C. After switching on the kneading stirrers, 3.6 kg of PET waste (97% PET) and 0.4 kg of adipic acid are fed in over 5 minutes via two metering screws. After 15 minutes, it is heated to 215-220 ° C, and molten oligoester condensate, PET waste and adipic acid are continuously fed at rates of 25, 18 and 2.0 kg per hour, respectively. After leaving the reaction zone, the mixture is transferred to a degassing zone, in which a reduced pressure of 110 mbar is set at a temperature of 160.degree. About the suction line and a distillation column a by-product stream of 2.1 kg / h is withdrawn, which consists essentially of water and ethylene glycol. After 30 minutes, the removal of a product stream of about 45 kg per hour is started, which is filtered. Samples are taken at intervals of 30 minutes. This gives a substantially constant product having a viscosity η ²⁵ of 6,500 mPas and an OH number of 265 mg KOH / g.

Example 4

In a reactor according to the invention as in Example 1 4.4 kg Oligoesterkondensat are melted according to claim 5 at 100 ° C in the reservoir, conveyed through a heated pump and heated pipes in the reactor and heated there to 210 ° C. After switching on the kneading stirrer, 4.0 kg of PET waste (97% PET) and 0.24 kg of adipic acid are fed in via two metering screws, and 0.64 kg of dipropylene glycol are supplied via a metering pump within 5 minutes. After 15 minutes, the mixture is heated to 215-220 ° C, and molten oligoester condensate, PET waste, adipic acid and dipropylene glycol are continuously fed at delivery rates of 22, 20, 3.2 and 1.2 kg per hour, respectively. After leaving the reaction zone, the mixture is transferred to a degassing zone in which a reduced pressure of 110 mbar is set at a temperature of 160.degree. About the suction line and a distillation column a by-product stream of 3.0 kg / h is withdrawn, which consists essentially of water and ethylene glycol. After 30 minutes, the removal of a product stream of about 45 kg per hour is started, which is filtered. Samples are taken at intervals of 30 minutes. A substantially constant product having a viscosity η ²⁵ of 4,700 mPas and an OH number of 320 mg KOH / g is obtained.

1

reactor

11

reactor housing

111

mixing and dissolution zone

112

reaction zone

113

post-reaction and discharge zone

114

melt connection

115

extruder connection

116

liquid inlet

117

discharge port

118

heating jacket (Mixing and dissolving zone)

119

heating jacket (Reaction zone)

120

heating jacket (Post-reaction and discharge zone)

121

Reactor bulkhead

122

reactor shell (Inside)

123

coat internals

124

Flow separation edge

125

Gaseinlasskapillare

126

kneading (stationary)

127

carrier segment (Kneading element stationary)

128

rotary vane

129

chamber plate

130

adjusting disk

131

rotor disc

14

hollow shaft

141

kneading and stirrer shaft

142

shaft casing (Kneading and stirring shaft)

143

bearing shaft (Kneading and stirring shaft)

144

carrier disc (Kneading and stirring shaft)

145

kneading and stirring element (Kneading and stirring shaft)

146

plaster and intake shaft

147

shaft casing (Cleaning and intake shaft)

148

bearing shaft (Cleaning and intake shaft)

149

carrier disc (Cleaning and intake shaft)

150

kneading and stirring element (Cleaning and intake shaft)

15

supply terminal (Hollow shaft)

151

supply terminal (Heating mantle)

16

Reactor interior

2

Promotional and metering

25

metering extruder

251

preheating

252

screw extruder

26

liquid dosage

261

reservoir

262

metering

27

dosage (Melt)

271

Reservoir, heated

272

dosing pump, heated

273

heater

3

temperature measurement

31

display part

32

Temperature sensor mixed and dissolution zone

33

Temperature sensor reaction zone

34

Temperature sensor post-reaction and discharge zone

4

hydraulic motor

5

tempering

6

discharge unit

61

Overflow device

62

filter unit

621

filter input

622

filter output

623

filter cartridge

63

Differential pressure measuring equipment

64

suction pump

7

distillation column

Claims (45)

Process for the preparation of polyols from linear polyesters such as polyethylene terephthalate, polybutylene terephthalate and / or polyethylene terephthalate or polybutylene terephthalate wastes, Oligoesterkondensaten, optionally hydroxyl-containing compounds and optionally aliphatic dicarboxylic acids, characterized in that a mixture of polyethylene terephthalate and / or polyethylene terephthalate waste, a Oligoestergemisch optionally one or more glycols, optionally other alcohols and optionally one or more aliphatic dicarboxylic acids in a mixing / kneading reactor with one or more horizontally rotating hollow shafts on which special mixing elements are arranged in one or more reaction and / or processing zones under continuous Throughput is reacted. Method according to claim 1, characterized in that that a) linear polyesters such as polyethylene terephthalate, polybutylene terephthalate and / or polyethylene terephthalate or Polybttylenterephthalat waste; an oligoester condensate, optionally one or more glycols, optionally other alcohols and optionally one or more aliphatic dicarboxylic acids continuously transported to the first zone of a mixing / kneading reactor, under Shear homogenized and tempered, b) the mixture is transported to a second zone of the reactor and there at another Shear, mixing and tempering is reacted, c) the mixture in a subsequent third zone optionally by applying a vacuum of volatile Components is released and d) the liquid product optionally freed by filtration of solid impurities and bottled. Method according to claim 1 or 2, characterized used as linear polyester polyethylene terephthalate waste become. Method according to claim 1 or 2, characterized that used as linear polyester contaminated PET waste. Process according to one of Claims 1 to 4, characterized in that the oligoester condensate used is a distillation product which comprises PET preparation and contains organometallic catalysts and has the following composition: 40-80% terephthalic acid, 5-30% bound ethylene glycol, 1- 20% free ethylene glycol, 1 - 20% bound diethylene glycol, 1 - 15% free diethylene glycol, 0 - 10% longer-chain ethylene glycols, 0.5 - 5% organometallic compounds. Method according to one of claims 1 to 5, characterized that as hydroxyl-containing compounds low molecular weight polyalkylene diols be used. Method according to one of claims 1 to 6, characterized from 5 to 65 parts by weight of polyester waste in a mixture of 5 to 65 parts by weight oligoester condensate, optionally 5 to 45 Parts by weight of diethylene glycol, polyethylene glycol and / or polypropylene glycol as low molecular weight polyalkylene diols and 0 to 30 parts by mass Alcohols such as butanediol-1,4, glycerol, trimethylolpropane, hexanetriol, Pentaerythritol, dipropylene glycol, oligopropylene glycols and / or oligoethylene glycols be implemented continuously. Method according to one of claims 1 to 7, characterized that the reaction mixture 5 to 40 parts by weight of an aliphatic or cycloaliphatic carboxylic acid, a dicarboxylic acid or an anhydride are added continuously. Method according to claim 8, characterized in that that as dicarboxylic acid adipic acid, sebacic, azelaic acid or maleic acid be used. Method according to one of claims 1 to 9, characterized that the reaction mixture in the first zone of the mixing / kneading reactor in a Residence time of 10 to 120 minutes at 150 to 280 ° C is heated. Method according to one of claims 1 to 9, characterized that the reaction mixture in the second zone of the mixing / kneading reactor at a residence time of 10 to 600 minutes and a temperature of 180 up to 280 ° C is implemented. Method according to one of claims 1 to 9, characterized if appropriate, the reaction mixture in the third zone of the mixing / kneading reactor at a residence time of 10 to 600 min and a temperature of 180 to 280 ° C is implemented. Method according to one of claims 1 to 9, characterized if appropriate, the reaction mixture in the third zone of the mixing / kneading reactor under a vacuum of 0.1 to 400 mbar of distillation for removal volatile by-products and impurities. Polyol, characterized by the production according to a method according to claims 1 to 13. Device for the production of recycled polyols from polyesters, characterized by - a horizontally arranged reactor ( 1 ) located in a reactor interior ( 16 ) one or more hollow shafts ( 14 ), which are mounted horizontally, parallel and rotatably, wherein the reactor interior ( 16 ) in the material flow direction into a mixing and dissolving zone ( 111 ), a reaction zone ( 112 ) and a post-reaction and discharge zone ( 113 ), - one with a temperature detection ( 3 ) functionally connected tempering unit ( 5 ), for a heat transfer in the or the hollow shafts ( 14 ) and in heating mantle (mixing and dissolving zone) ( 118 ), Heating jacket (reaction zone) ( 119 ) and heating mantle (post-reaction and discharge zone) ( 120 ), - a drive ( 4 ) of the hollow shafts ( 14 ), - one with the mixing and dissolving zone ( 111 ) conveying and metering device ( 2 ) and - one with the post-reaction and discharge zone ( 113 ) associated discharge unit ( 6 ). Apparatus according to claim 15, characterized in that the hollow shafts ( 14 ) on its surface kneading and stirring elements ( 145 . 150 ) are arranged so that their surfaces with a reactor shell (inside) (inside) ( 122 ) and / or with the surfaces of the kneading and stirring elements ( 145 . 150 ) of adjacent hollow shafts ( 14 ) form in the rotation of constantly narrowing and re-opening column. Apparatus according to claim 15 or 16, characterized in that the conveying and metering device ( 2 ) a liquid dosage ( 26 ) with reservoir ( 261 ) and metering pump ( 262 ) and a solids feed ( 23 . 22 . 21 . 25 ) having. Device according to one of claims 15 to 17, characterized in that a metering screw ( 21 ) or an extruder screw ( 252 ) below the liquid level on the reactor ( 1 ) is arranged. Device according to one of claims 15 to 18, characterized in that the extruder screw ( 252 ) outside the reactor ( 1 ) and its heatable jacket ( 118 ) and operable at ambient temperature. Device according to one of claims 15 to 19, characterized in that the extruder screw ( 252 ) has a heater. Device according to one of claims 15 to 20, characterized in that the conveying and metering device ( 2 ) tangential to the reactor ( 1 ) and is arranged in the direction of rotation of the kneading and stirring elements. Device according to one of claims 15 to 21, characterized in that the reactor ( 1 ) and a reactor housing ( 11 ) are formed of cylindrical individual parts and a reactor shell (inside) ( 122 ) of the reactor ( 1 ) with stationary kneading elements ( 126 ) is equipped in such a way that this with the kneading and stirring elements ( 145 . 150 ) on the shaft surface ( 142 ) of the hollow shaft ( 14 ) are communicable. Device according to one of claims 15 to 22, characterized in that the reactor ( 1 ) and the reactor housing ( 11 ) are connected from cylindrical sections in such a way that they give an eight-shaped cross-section, the respective center of the circle with the center lines of the hollow shafts ( 14 ) and their wave shell surfaces ( 132 ) fall together. Device according to one of claims 15 to 23, characterized in that the reactor ( 1 ) and the reactor housing ( 11 ) consist of cylindrical sections with the same diameters. Device according to claim 24, characterized in that the reactor ( 1 ) and the reactor housing ( 11 ) consist of cylindrical sections with different diameters. Device according to one of claims 15 to 25, characterized in that the mixing and dissolving zone ( 111 ), Reaction zone ( 112 ) and post-reaction zone ( 113 ) are divided and are separately tempered. Device according to one of claims 15 to 26, characterized in that in axial arrangement of the reactor ( 1 ) the hollow shafts ( 14 ) with the wave shell surfaces in the mixing and dissolving zone ( 111 ), the reaction zone ( 112 ) and the post-reaction zone ( 113 ) have different free cross sections, which cause different flow velocities of the tempering. Device according to one of claims 15 to 26, characterized in that the kneading and stirring elements ( 145 . 150 ) on the shaft surface ( 132 ) are arranged on an ideal helical line. Device according to one of claims 15 to 27, characterized in that the kneading and stirring elements ( 145 . 150 ) on the shaft surface ( 132 ) are arranged more or less on ideal helical lines. Device according to one of claims 15 to 29, characterized in that the number of helical arrangements of the kneading and stirring elements ( 145 . 150 ) on the shaft shell surfaces of the individual hollow shafts ( 14 ) is opposite and different, but constantly at the rotation of the hollow shafts ( 14 ) are communicable with each other in a common area. Device according to one of claims 15 to 29, characterized in that the respective arrangement of the kneading and stirring elements ( 145 . 150 ) from the beginning of the mixing and dissolving zone ( 111 ) to the middle of the reaction zone ( 112 ) lag behind the ideal helices, the ideal helixes are in the middle of the reaction zone ( 112 ) and from there to the end of the post-reaction zone ( 113 ) lead the ideal helices. Device according to one of claims 15 to 29, characterized in that the respective arrangement of the kneading and stirring elements ( 145 . 150 ) are described by individual sections of linear functions which are superimposed on the respective ideal helices. Device according to one of claims 15 to 29, characterized in that the respective arrangement of the kneading and stirring elements ( 145 . 150 ) is described by selected modified trigonometric functions superimposed on the respective ideal helical lines. Device according to one of claims 15 to 33, characterized in that the tempering medium tangentially in the space of the hollow shaft ( 14 ) to the shaft surface ( 142 . 147 ) is einlassbar and the flow direction of the tempering against the working direction of the reaction mixture in the reactor ( 1 ) runs. Device according to one of claims 15 to 34, characterized in that the kneading and stirring elements ( 145 . 150 ) are negatively undercut at the edges in the direction of rotation. Device according to one of claims 15 to 35, characterized that the negatively undercut edges have an acute angle. Device according to one of claims 15 to 36, characterized that the negative undercut edges have an acute angle, the are rounded by a radius. Device according to one of claims 15 to 37, characterized in that the kneading and stirring elements ( 145 . 150 ) to the corresponding shaft surface ( 142 . 147 ) have a continuously narrowing gap during the rotation passage. Device according to one of claims 15 to 38, characterized in that the kneading and stirring elements ( 145 . 150 ) to the adjacent stirring elements ( 145 . 150 ) on the corresponding shaft surface ( 142 . 147 ) have a continuously narrowing gap during the rotation passage. Device according to one of claims 15 to 39, characterized in that on the inner surface of the jacket of the reactor ( 1 ) wedge-shaped constrictions are mounted with a sharp-edged spoiler edge, which, in cooperation with the negatively undercut edges of the kneading and stirring elements ( 145 . 150 ) form a constantly narrowing gap during the passage. Device according to one of claims 15 to 40, characterized in that below the separation edges capillaries end, through which a protective gas or active gas into the reactor ( 1 ) can be initiated. Device according to one of claims 15 to 41, characterized in that the mixing and dissolving zone ( 111 ) from the reaction zone ( 112 ) and the reaction zone ( 112 ) from the post-reaction zone ( 113 ) in the reactor ( 1 ) by a rotary valve ( 128 ) are separable. Device according to one of claims 15 to 42, characterized in that the rotary valve system ( 127 ) consists of a stationary plate with at least one aperture of different shape, on which one around the center of rotation of the hollow shafts ( 14 ) is mounted pivotable plate with one or more openings for variable adjustment of the cross section of the stationary system, on which a rotor plate with at least one breakthrough in the same direction with the rotation of the respective hollow shafts ( 14 ) and thereby covers the openings of the stationary plate and the pivotable plate at adjustable time intervals. Device according to one of claims 15 to 43, characterized in that via an angular offset of the stationary plates of the rotary valve system ( 127 ) between the reaction zone ( 112 ) and the mixing and dissolving zone ( 111 ) and between the reaction zone ( 112 ) and the post-reaction zone ( 113 ) to each other only a rotary valve system ( 127 ) is always switched to passage. Device according to one of claims 41 to 43, characterized in that the openings always below the liquid level in the reactor ( 1 ) are located.