Process for recycling polyurethane waste through remonomerization by hydroaminolysis

Abstract

The present invention is directed to a process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (I1) and polyol (P1), depolymerization of the comminuted polyurethane or polyisocyanurate provided in the presence of water and / or amine catalyst, addition of an inorganic basic component to cleave eventually formed ammonium salts, separation of the amine component derived from depolymerization and the polyol components obtained in an amine rich and an amine poor phase, addition of an acidic component to the amine poor phase, to acidify the formed carboxylates of the weak acids, and treatment of the polyol components in the amine poor phase to form a polyol (P2). Furthermore, the present invention is directed to the polyol composition and the isocyanate composition obtained in said process and the use of the polyol composition and the isocyanate composition or the preparation of polyurethanes or polyisocyanurates.

Description

[0001] Process for recycling polyurethane waste through remonomerization by hydroaminolysis

[0002] The present invention is directed to a process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1 ), depolymerization of the comminuted polyurethane or polyisocyanurate provided in the presence of water and amine catalyst, addition of an inorganic basic component to cleave eventually formed ammonium salts, separation of the amine component derived from depolymerization and the polyol components and / or polyol fragments obtained in an amine rich and an amine poor phase, addition of an acidic component to the amine poor phase, to acidify the formed carboxylates of the weak acids, and treatment of the polyol components in the amine poor phase to form a polyol (P2). Furthermore, the present invention is directed to the polyol composition and the isocyanate composition obtained in said process and the use of the polyol composition and the isocyanate composition or the preparation of polyurethanes or polyisocyanurates.

[0003] Products containing polyurethane materials are widely used in industry and in everyday applications. Because of the tremendous and still increasing prevalence of polyurethane materials, there is a large amount of waste of polyurethane materials (e.g., from old mattresses or seating furniture, car seats, refrigerators or insulation boards). This waste of polyurethane materials should be used appropriately and as ecologically friendly as possible. One way of such use of polyurethane materials is the recovery of raw materials from the polyurethane materials. Apart from so- called mechanical recycling methods, which teach a physical comminution, chemical recycling processes are known.

[0004] Remonomerization strategies discussed in the literature and patents include hydrolysis, glycolysis, aminolysis and acidolysis. For example WO 2021 / 023889 A1 discloses a method for alcoholizing and hydrolyzing polyurethane materials.

[0005] In general, hydrolysis techniques lead to a CO2 release, which dissolves in water as carbonic acid under pressure and leads to a deactivation of the mostly basic catalysts. Especially in the literature, frequently used inorganic strong bases, such as sodium hydroxide or potassium hydroxide irreversibly deactivate. In addition, poorly soluble salts are often formed, which represent a challenge in the process engineering process. Another aspect is the splitting of polyester polyols. These consist mainly of dicarboxylic acids and glycols. The ester bonds are not stable in a hydrolytic remonomerization strategy and there is a cleavage of the polyester polyols into the monomer building blocks. The released acids react with the bases used as catalysts to carboxylate salts and with the released amine (toluene diamine or methylene diphenyl diamine) to ammonium salts, which can lead to a reduction in the yield of valuable products. For further processing, the salts must be converted back into the corresponding acids, which is associated with a further process engineering effort.

[0006] WO2023 / 208946 discloses a method for recovering raw materials from isocyanurate-containing polyurethane products. The method is characterized by reacting the isocyanurate-containing polyurethane product with liquid water at a temperature in the range of 130°C to 260°C and a pressure in the range of 1 .0 bar to 100 bar in the presence of a catalyst, thereby obtaining a chemolysis product, and subsequently reprocessing the chemolysis product and as a result obtaining (I) an amine that corresponds to an isocyanate of the isocyanate component, and optionally (II) a polyol of the polyol component or a reaction product of a polyol of the polyol component.

[0007] In many processes, the problem is an irreversible reaction of the catalysts used with carbon dioxide, especially for hydrolytic depolymerization reactions under pressure. On the one hand, this leads to a reduced yield of polyols and amine monomers. In addition, insoluble solids are formed, which make downstream processing technically difficult. The circularity of the catalyst is also no longer given.

[0008] In view of the above, it is an object of the present invention to provide a process to recover raw materials from polyurethane materials which is as simple as possible, and which allows to recover raw materials having an optimized quality.

[0009] The problem is solved according to the present invention by a process for recycling of polyurethane or polyisocyanu- rate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate foam which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and a monofunctional primary or secondary amine as catalyst (CA), and optionally adding a solvent which has a miscibility gap with water c) addition of an inorganic basic component to cleave eventually formed ammonium salts, d) separation of the amine component derived from depolymerization and the polyol components or polyol fragments obtained in step c), in an amine rich and an amine poor phase; e) addition of an acidic component to the amine poor phase, to treat the formed carboxylates of the weak acids; f) treatment of the polyol components in the amine poor phase to form a polyol (P2).

[0010] The process according to the present invention comprises steps a), b), c), d), e) and f) but may comprise further steps. It has been found that the specific sequence of process steps according to the present invention allow to recover raw materials from polyurethane or polyisocyanurate materials in high quality in a simple manner. It has surprisingly been found that using the specific depolymerization conditions and purification steps according to the present invention, the amine present reacts with CO2 to form metastable carbamic acids. These metastable acids can be easily cleaved by reducing the pressure through the hydrolytic depolymerization reaction or after the reaction via flashing the reactor content. The pressure released reaction mixture preferably is filtered and purified by a subsequent extraction. In the extract, the amine-rich phase is obtained, while the polyols or polyol fragments remain in an amine poor phase.

[0011] It has been found that the process is particularly suitable for the recycling and remonomerization of polyurethane or polyisocyanurate foams. Thus, according to the present invention, the polyurethane or polyisocyanurate material preferably is a polyurethane or polyisocyanurate foam, in particular a flexible or rigid polyurethane foam.

[0012] It has been found that the presence of the carbamates significantly improves the phase separation. According to the process of the present invention, it is possible to recover both starting material components from the polyurethane or polyisocyanurate. The polyurethane or polyisocyanurate components are either recovered directly, for example the polyols or fragments of those, or are obtained as valuable synthesis building blocks such as polyamines which may readily be converted to polyisocyanates.

[0013] According to step a), a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1 ), is provided.

[0014] In the context of the present invention, a "comminuted polyurethane or polyisocyanurate material” means the material is obtained from a material and the comminuted polyurethane or polyisocyanurate is for example used in shredded form, in the form of granules, flakes, as an agglomerate, or as a powder. The polyurethane or polyisocyanurate materials can be comminuted by conventional methods, for example by shredding, e.g. in a ball mill or rotary mill at room temperature, to a particle size of ordinarily less than 500 mm, for example to a particle size in the range of from 10 to 500 mm, preferably to a particle size of less than 20 mm, or ground, e.g. by known cold grinding processes. Preferably, for a milled material a particle size of less than 5 mm is selected, for example a particle size in the range of 0.01 mm to 5 mm, and preferably in the range of 0.01 mm to 1 mm.

[0015] The properties of the polyurethane or polyisocyanurate materials might vary in broad ranges. Preferably, polyurethane materials are used in the process of the present invention.

[0016] The polyurethane or polyisocyanurate materials used in the present invention are preferably obtained from items produced from polyurethane materials at a time after use for the purpose for which they were manufactured or polyurethane material waste from production processes. Before subjecting to the process of the present invention, the items may be subjected to sorting steps and / or to mechanical comminution. That is, further sorting and bringing the items into appropriate sizes, e.g., by shredding, sieving or separation by rates of density, i.e. by air, a liquid or magnetically. Optionally, these fragments may then undergo processes to eliminate impurities, e.g. paper labels. Furthermore, steps to remove blowing agents may be included in the process. Suitable methods are in principle known to the person skilled in the art.

[0017] Herein, the term "polyurethane material waste” includes end-of-life polyurethane materials and production rejects of PU materials or waste generated through further processing of PU materials. In this context, the term "spent polyurethane material” denotes an item produced from a polyurethane material at a time when it has already been used for the purpose for which it was manufactured. "Production rejects of polyurethane materials" denotes polyurethane material waste occurring in production processes of PU materials.

[0018] Generally, polyurethane materials are produced by a reaction between a polyisocyanate component and a polyol component. Typically, further materials, in particular additives, such as flame retardants (e.g. phosphorous-based), polymerization catalysts (e.g. tertiary amines), fillers and surfactants as siloxanes can be added in the production process of the polymers.

[0019] The properties of a polyurethane material are influenced by the chemistry of polyisocyanate and polyol components used and the recipe applied in polymerization. For example, the starting materials may influence the crosslinking density of the polymers in a three-dimensional network. Rigid polyurethanes are typically obtained from monomers with a comparably low molecular weight and high functionality creating a highly crosslinked, dense network. Typically, the polyol substance comprises or consists of one or more polyols having a molecular weight of about 150 to about 4000 g / mol, a nominal OH functionality of about 1 to 6, preferably between 2 to 5 is used, in particular in the range of from 2 to 4.5, more preferable in the range of from 2 to 4.3, most preferable in the range of from 2 to 4.0 and having an OH number of about 25 mg KOH / g to about 1000 mg KOH / g, in particular from 30 to 500 KOH / mg.

[0020] Industrially and consequently in large quantities, especially methylenedi(phenylisocyanate) (MDI) or its polymeric forms or toly lene-2,4 and 2,6-diisocy anate (TDI) are used as polyisocyanate components for the production of PU rigid foams and PU flexible foams. For a representative composition of these PU foams, see for example US 9,023,907 B2, WO 2015 / 121057 and WO 2013 / 139781.

[0021] Organic polyisocyanates that can be used in the preparation of polyurethanes are any of the known organic polyisocyanates, preferably aromatic polyfunctional isocyanates. In the context of the present invention, the term polyisocyanate encompasses isocyanates with 2 or more isocyanate groups, i.e. also diisocyanates.

[0022] Suitable polyisocyanate components used for the production of the polyurethanes or polyisocyanurates comprise any of the polyisocyanates known for the production of polyurethanes or polyisocyanurates. These comprise the aliphatic, cycloaliphatic, and aromatic difunctional or polyfunctional isocyanates known from the prior art, and also any desired mixtures thereof. Examples are diphenylmethane 2, 2'-, 2,4'-, and 4,4’-diisocy anate, the mixtures of monomeric diphenylmethane diisocyanates with diphenylmethane diisocyanate homologs having a larger number of rings (polymer MDI), isophorone diisocyanate (IPDI) and its oligomers, tolylene 2,4- and 2,6-diisocyanate (TDI), and mixtures of these, tetramethylene diisocyanate and its oligomers, hexamethylene diisocyanate (HDI) and its oligomers, naphthylene diisocyanate (NDI), and mixtures thereof.

[0023] Preferably, tolylene 2,4- and / or 2,6-diisocyanate (TDI) or a mixture thereof, monomeric diphenylmethane diisocyanates, and / or diphenylmethane diisocyanate homologs having a larger number of rings (polymer MDI), and mixtures of these. Other possible isocyanates are mentioned by way of example in "Kunststoffhandbuch [Plastics handbook], volume 7, Polyurethane [Polyurethanes]", Carl Hanser Verlag, 3rd edition 1993, chapter 3.2 and 3.3.2.

[0024] The organic di- and polyisocyanates may be used individually or in the form of mixtures.

[0025] Common polyols used in huge quantities are, e.g., selected from the group consisting of polyether polyols, polyester polyols, polyetherester polyols, polyether polycarbonate polyols and mixtures thereof.

[0026] Polyetherols are by way of example produced from epoxides, for example propylene oxide and / or ethylene oxide, or from tetrahydrofuran with starter compounds exhibiting hydrogen-activity, for example aliphatic alcohols, phenols, amines, carboxylic acids, water, or compounds based on natural substances, for example sucrose, saccharose, sorbitol or mannitol, with use of a catalyst. Mention may be made here of basic catalysts and double-metal cyanide catalysts, as described by way of example in WO 2006 / 034800, EP 0090444, or WO 2005 / 090440.

[0027] Polyesterols are by way of example produced from aliphatic or aromatic dicarboxylic acids and polyhydric alcohols, polythioether polyols, polyesteramides, hydroxylated polyacetals, and / or hydroxylated aliphatic polycarbonates, preferably in the presence of an esterification catalyst. Other possible polyols are mentioned by way of example in "Kunststoffhandbuch [Plastics handbook], volume 7, Polyurethane [Polyurethanes]", Carl Hanser Verlag, 3rd edition 1993, chapter 3.1.

[0028] Polyether polycarbonate polyols are by way of example produced from propylene oxide and CO2 by copolymerization using metal-based catalysts. Examples for catalysts used to produce polyether polycarbonate polyols are DMC-cata- lysts or so called salen catalysts.

[0029] Polyesterpolyols may for example be selected from polyester alcohols whose OH numbers are in the range from 25 to 800 mg KOH / g, in particular from 30 to 500 KOH / mg. The polyester alcohols used are mostly prepared via condensation of polyhydric alcohols, preferably polyetherpolyols with a molecular weight up to 800 g / mol, preferably up to 650 g / mol, or diols, having from 2 to 12 carbon atoms, preferably from 2 to 6 carbon atoms, with polybasic carboxylic acids having from 2 to 12 carbon atoms, e.g. succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, or preferably phthalic acid, isophthalic acid, terephthalic acid, or the isomeric naphthalenedicarboxylic acids. Also, cyclic anhydrides may be used such as for example phthalic acid dianhydride. According to step b) of the process of the present invention, the comminuted polyurethane or polyisocyanurate provided in step a) is depolymerized in the presence of water and a monofunctional primary or secondary amine as catalyst (CA). Optionally a solvent which has a miscibility gap with water is added as step b1).

[0030] Water and a monofunctional primary or secondary amine as catalyst are added in suitable amounts to achieve depolymerization of the polyurethane or polyisocyanurate. Suitable amine catalysts include but are not limited to aliphatic and / or aromatic amines, in particular in a molar range from 31 g / mol to 186 g / mol.

[0031] Suitable solvents which have a miscibility gap with water are in principle also known to the person skilled in the art. Suitable are for example toluene or cyclohexane.

[0032] According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the monofunctional primary or secondary amine are selected from the group consisting of aliphatic and / or aromatic amines in a molar range from 31 g / mol to 186 g / mol.

[0033] Preferably, aromatic amines are used as a catalyst such as for example aniline or toluidine.

[0034] Preferably, the mass ratio of the amine and the polyurethane or polyisocyanurate is in the range of 10: 1 to 1 :3. Preferably the mass ratio of water and polyurethane or polyisocyanurate is in the range of from 10: 1 to 1 :2.

[0035] In principle, suitable conditions for the depolymerization may vary in broad ranges. The reaction may be for example carried out in a stirred tank or stirred tank cascade or plug flow reactor. The reaction temperature preferably is in a range of 170°C to 250°C. The weight ratio of water to polyurethane or polyisocyanurate material is preferably in a range of 1 to 1 (kg / kg) to 10 to1 (kg / kg) and the weight ratio of the organic solvent which contains a miscibility gap with water to polyurethane or polyisocyanurate material is preferably in the range of 0.2 to 1 (kg / kg) to 5 to 1 (kg / kg) . Typically, the reaction time is between 0.5 and 10 h and the reaction pressure may typically be between 5 and 80 bar.

[0036] During depolymerization of the polyurethane or polyisocyanurate material, a mixture containing a polyol substance and an amine substance is formed. Due to the addition of water or due to water being present in the composition, a hydrolysis of the polyurethane or polyisocyanurate material occurs. The presence of at least equimolar amounts of water can lead to about 100% amine liberation. According to the present invention, a monofunctional primary or secondary amine as catalyst (CA), and optionally a solvent which has a miscibility gap with water may be added in step b) and step b1) respectively.

[0037] After depolymerization, the process of the invention typically yields a polyamine comprising an amino group attached to the carbon atom to which in the initial polyisocyanate an isocyanate group was bound, e.g., methylene diphenyl diamines (MDA), oligomeric and polymeric methylene phenylene amine, toluenediamines (TDA), in particular 2,4- toluenediamine or 2,6-toluenediamine, hexamethylene diamine (HDA), and naphthylene diamines (NDA). The commonly used polyols as described above preferably also can be re-isolated. Thus, the process preferably further yields polyol components comprising polyols or fragments of polyols, e.g. polyester polyols, fragments of polyesterpolyols, low molecular weight polyols such as ethylene glycol or propylene glycol, or high molecular weight polyether polyols based on glycerol, sorbitol, ethylene glycol, polypropylene glycol and polytetramethylene glycol.

[0038] According to step c) of the process according to the present invention, an inorganic basic component is added to the mixture obtained to cleave eventually formed ammonium salts. Suitable inorganic basic components may for example be alkali metal hydroxides or earth alkali hydroxides, preferably potassium hydroxide or sodium hydroxide. The inorganic basic component is added in an amount suitable to cleave ammonium salts formed. Preferably, the molar ratio of the inorganic basic component and the ammonium salts is in the range of from 1 .0 / 1 to 2.0 / 1 .

[0039] The components obtained in the depolymerization may be separated. It is also possible in the context of the present invention to separate by-products such as for example carbon dioxide, catalyst components or waste materials prior to a separation of the amine component and the polyol components. Carbon dioxide may be separated off and may be dried and further purified by known conventional methods. It is also possible to use the carbon dioxide obtained in the process for further processes, for example as a reactant for urea or soda or as carbon precursor for the synthesis of organic molecule. Thus, according to a further embodiment, the present invention is also directed to the process as disclosed above, wherein carbon dioxide released in the process is used as carbon building block for chemical processes, preferably for the preparation of urea, soda, carbon monoxide. For example, soda could be produced via an alkaline washing step.

[0040] According to step d) of the process of the invention, the amine component derived from depolymerization and the polyol components or polyol fragments obtained in step c), are separated in an amine rich and an amine poor phase.

[0041] Preferably, the process comprises allowing the mixture to settle. According to the present invention, it is possible that one or more phases are formed and the components of the mixture may be separated by suitable separation steps. According to the present invention, it is for example possible to extract the mixture via an organic anhydrous solvent which is not or partially miscible with water.

[0042] In particular in embodiments, in which the amine substance is recovered, it can be beneficial if an excess of water is removed from the mixture, before allowing the mixture to settle, preferably by evaporation of the excess of water. In particular, for evaporation of the excess of water, the mixture is heated and / or a vacuum is applied. For example, an excess of water is removed by using flash evaporation or applying vacuum to the already heated mixture. For example, a water removal step may be performed for about 120 minutes or less, in particular about 90 minutes or less, for example about 75 minutes or less, for example about 60 minutes or less. Preferably, the water removal step is performed for about 10 minutes or more, in particular for about 30 minutes or more, for example for about 40 minutes or more. The process of the present invention further comprises step e). According to step e), an acidic component is added to the amine poor phase, to acidify the formed carboxylates of the weak acids. The pH-value preferably should be lower than 5 after acid dosage.

[0043] According to step f) of the process according to the present invention, the polyol components or polyol fragments in the amine poor phase are treated to form a polyol (P2). Typically, the amine poor phase comprises polyol components such as glycols and may also comprise mono- or diacids in case polyesterpolyols are present in the polyurethane or polyisocyanurate. The treatment according to step f) may comprise further treatments such as for example thermal treatments and / or vapor stripping to obtain the free acid prior to re-esterification of the polyol fragments. Suitable conditions for example for re-esterification are known to the person skilled in the art. The amine poor phase may also be treated to remove further by-products or solvents. The ratio of acids and polyalcohols is typically adjusted to obtain a mixture which is then suitable as a starting material for esterification of the acids and polyalcohols. Preferably, the ratio of acids is adjusted to a molar ratio of acid groups to hydroxy groups in the range of from 1 : 1.03 to 1 :2.5, in particular to 1 : 1 .05 to 1 :2.0.

[0044] The process may for example comprise steps such as adding diacids to the mixture; adding polyalcohols to the mixture; adding esterification catalysts, for example titan tetrabutanolate; removal of diols by evaporation / distillation; or removal of solvent from the mixture. The process may furthermore comprise suitable treatment steps to achieve condensation of polyalcohols and acids in the mixture. In particular suitable to achieve re-condensation of polyols and acids. Suitable conditions for example for re-esterification are known to the person skilled in the art and may for example include condensation of alcohols and acids by heating under vacuum and removal of condensation product, online analytics to follow reaction progress and optionally adjust monomer composition.

[0045] After work-up, the polyol-containing phase may be used at least proportionally in new PU formulations. After purification, the polyamine preferably can be converted back to the corresponding isocyanate, for example by means of phosgenation, and as such can then be used at least proportionally as an isocyanate component in PU production. Alternatively, a reactive extraction of the polyamine with hydrogen chloride can be utilized as purification method according to the present invention. The formed polyamine-hydrochloride can be converted back to the corresponding isocyanate by means of direct phosgenation or can be transferred to an existing amine production plant. Suitable processes and reaction conditions are in principle known to the person skilled in the art.

[0046] The process according to the present invention comprises steps a), b), c), d), e) and f), but may also comprise further steps. The process may for example comprise further purification steps or heat treatments. According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the process comprises further purification steps. Suitable treatment steps are in principle known to the person skilled in the art. Suitable treatment and / or purification steps may be carried out between steps a) and b), or between steps b) and c), or between steps c) and d) or between steps d) and e) or between steps e) and f). In the context of the present invention it is also possible that step b) is carried out directly after step a). It is also possible that step c) is carried out directly after step b). Furthermore, it is possible that step d) is carried out directly after step c) or that step e) is carried out directly after step d). It is also possible that step f) is carried out directly after step e).

[0047] According to the present invention, steps a) and b) might also be combined and carried out in the same apparatus. It is also possible that the composition provided in step a) might also comprise solvents, for example solvents which might be used in step b) of the process according to the present invention.

[0048] The work-up of the depolymerization product, in particular the isolation of the polyamine and the polyol can be realized case dependent, for example by extractive work-up, precipitation of the amine component as a hydrochloride, chromatography or distillation under reduced pressure. Preferably, the work up comprises several steps.

[0049] According to one aspect of the invention, solids may be removed from the mixture before or after the mixture is allowed to settle, preferably by one or more of the following: filtration, centrifugation, decantation.

[0050] It is for example possible to remove solid components such as for example solid components or flame retardants from the comminuted polyurethane or polyisocyanurate material by suitable methods such as for example extraction. Solid components may be for example residues of coatings or waste fragments or also solid additives. The flame retardants may also be purified via additional extraction, adsorption, crystallization, or distillation process steps and reused. According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the process further comprises a step a1) a1) at least partial extraction of flame retardants from a comminuted polyurethane or polyisocyanurate material.

[0051] Suitable conditions for step a1) are for example disclosed in EP 22205386.0.

[0052] According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the process further comprises a step b2) b2) removal of particulate solids from the reaction mixture.

[0053] Suitable methods for removal of particulate solids are in principle known to the person skilled in the art. For example, filtration units or a centrifuge may be used. Preferably, a filtration step is carried out according to the present invention using a filtration unit, more preferably a filter, more preferably a pocket filter, a bag filter, a membrane filter, a candle filter, an agitated pressure filter, a vacuum belt filter, a frame & plate filter, or a nutsche filter. For filtration, preferably filter membranes having an average mesh size of about 30 pm or less may be used. It can be beneficial to use a cascade of filters. For example, a first filter membrane of the cascade of filters has an average mesh size of about 250 pm to about 290 pm. A second filter membrane of the cascade of filters preferably has an average mesh size of about 50 pm to about 90 pm and, in particular, a third filter membrane of the cascade of filters has an average mesh size of 20 pm or less.

[0054] In the alternative or additionally, centrifugation is a preferred solid-liquid-separation method.

[0055] Further separation steps may be carried out, for example separation steps to separate gaseous components such as for example carbon dioxide. Suitable separation methods are known to the person skilled in the art, such as for example evaporation or adsorption steps.

[0056] In work-up by distillation, compounds are separated according to their volatility, with more volatile compounds being separated first. Additives, water, the utilized amine catalysts or solvents used in the depolymerization can also be removed via distillation prior further work-up of the polyol-polyamine mixtures. Generally, the "volatility” of a liquid may be described using its vapor pressure, wherein a high vapor pressure indicates a high volatility, and vice versa.

[0057] In the event that the polyamine is more volatile than the polyol as it is for example the case for TDA, monomeric MDA and NDA, the polyamine is recovered from the depolymerization product via distillation, preferably via distillation at reduced pressure. After distilling-off the polyamine, a distillation bottoms remains which contains the polyol.

[0058] Suitable conditions for the distillation are in principle known to the person skilled in the art and are for example disclosed in EP22178796.3 or EP22178797.1.

[0059] Alternatively, the polyol may be recovered by extraction from the depolymerization mixture using a suitable extractant or a pair of extractants. It is also possible to precipitate the polyamine component in the form of its hydrochloride by adding HCI and extracting the polyol component with a suitable solvent for example as described in DE2854940A1, which is preferably dissolving the polyol component but not the hydrochlorides of the polyamine component. It is also possible to adjust the conditions in the extraction step to recover the polyamine component using aqueous HCI as extraction medium. The hydrochloride of the polyamine component can after separation then either be transferred to the free polyamine by adding a base but also directly used in the phosgenation to generate new polyisocyanates for the polyurethane synthesize. Also, thermal cleavage of the hydrochloride is possible in the context of the present invention. It is for example possible to feed the amine hydrochloride directly in a process for the preparation of the respective amine. For example, in case of MDA*HCI or PMDA*HCI the hydrochloride can be directly fed to an MDA synthesis plant at a position prior to the neutralization step. Also, in case aniline is present in the reaction, aniline hydrochloride formed may be directly fed to an MDA synthesis plant. Further, in particular for recovering the polyol substance, the process comprises preferably a work-up of the phase, which is polyol substance rich by purification of the polyol substance. The purification may comprise one or more of the following:

[0060] - filtration;

[0061] - centrifugation;

[0062] - decanting;

[0063] - distillation;

[0064] - full or partial evaporation of the phase in one or more evaporators;

[0065] - contacting the phase with an ion exchange material;

[0066] - contacting the phase with one or more adsorbents.

[0067] Preferably, the process further comprises work-up of the mixture by purification of the amine substance, for example including distillation, in order to purify the amine substance.

[0068] Therefore, according to a further embodiment, the present invention is directed to the process as disclosed above, wherein the process further comprises step h) h) purification of the amine rich phase.

[0069] The process of the present invention therefore also comprises embodiments, wherein step h) comprises the extraction of the amine component using aqueous HCI. According to a further embodiment, the present invention therefore is also directed to the process as disclosed above, wherein the hydrochloride of the polyamine component is formed in the process and the hydrochloride is transferred to the free polyamine by adding a base or by thermal cleavage or the hydrochloride is directly used in the phosgenation.

[0070] It is understood that the separation process described above can be combined with any of the various embodiments of the inventive process described herein.

[0071] With the process of the present invention, about 90 % or more, preferably about 97 % or more, of the polyol substances or monomer fragments of those which is theoretically recoverable from the polyurethane material can be released. Due to decomposition of monomers or incomplete recovery, the yield of the polyol substances or monomer fragments of those may be differ from 97 %.

[0072] According to a further aspect, the present invention is also directed to the polyol composition obtained or obtainable according to the process of the present invention. The molecular weight and chemical structure of the polyols may vary in broad ranges. Preferably, the polyol composition for flexible foams comprises or consists of one or more polyols having a molecular weight of about 2000 to about 6000 g / mole, a nominal OH functionality of about 3 and having an OH number of about 28 mg KOH / g to about 60 mg KOH / g.

[0073] Preferably, the polyether polyol composition for rigid foams comprises or consists of one or more polyols having a molecular weight of about 300 to about 800 g / mole, a nominal OH functionality of about 3-8 and having an OH number of about 200 mg KOH / g to about 800 mg KOH / g.

[0074] Furthermore, according to a further embodiment, the polyol composition may comprise or consist of one or more polyols having a molecular weight of about 3000 to about 12000 g / mole, a nominal OH functionality of about 3 and having an OH number of about 20 mg KOH / g to about 50 mg KOH / g.

[0075] According to a further aspect, the present invention is also directed to the use of the polyol composition according to the present invention or a polyol composition obtained or obtainable according to the process of the present invention for the preparation of polyurethanes or polyisocyanurates. Furthermore, the polyol fragments obtained in the process may be used as building blocks for the preparation of high molecular polyester polyols or as precursor for chemicals.

[0076] The present invention further relates to a process for preparing a polyurethane material by reacting the polyol substance obtained by the process according to the present invention with an isocyanate substance, preferably the isocyanate substance obtained by a process of the present invention.

[0077] According to a further embodiment, the present invention relates to the use of the polyol composition according to the present invention or a polyol composition obtained or obtainable according to the process as disclosed above for the preparation of polyurethanes or polyisocyanurates.

[0078] The present invention further relates to a process for preparing a polyurethane material by reacting the polyol substance obtained by the process according to the present invention with an isocyanate substance, preferably the isocyanate substance obtained by a process of the present invention.

[0079] Furthermore, the invention relates to a process for producing an isocyanate substance from an amine substance obtained by a process according to the present invention. The advantages and / or features described in connection with the process for recovering an amine substance also apply for the process for producing an isocyanate substance.

[0080] Preferably, the amine substance resulting from the recovery process is fed into a purification section of an amine producing plant, an amine storage tank or an isocyanate producing plant, for example in the phosgenation section of an isocyanate production plant. For the use of the amine substance in the isocyanate production, the amine substance needs to be essentially free of polyol substance, residual metals and silicon compounds. In the context of the present invention, "essentially free” means that the content of the respective components is less than 1 wt.%, in particular less than 0.5 wt.%, more preferable less than 0.25 wt.%.

[0081] Preferably the amine substance is phosgenated so that an isocyanate substance is formed. For example, TDA may be phosgenated to prepare TDI or MDA may be phosgenated to prepare MDI. Furthermore, pMDA may be phosgenated to prepare pMDI and NDA may be phosgenated to prepare NDI. Suitable conditions for the phosgenation are in principle known to the person skilled in the art.

[0082] According to a further embodiment, the present invention therefore is also directed to the process as disclosed above, wherein the process further comprises step g) g) conversion of the amine component to obtain an isocyanate composition.

[0083] In the context of the present invention, the term "isocyanate composition” encompasses all isocyanates known to the person skilled in the art in connection with polyurethane chemistry, such as, in particular, toluene diisocyanate (TDI; prepared from toluene diamine, TDA) or the di- and polyisocyanates of the diphenylmethane series (MDI; prepared from the di- and polyamines of the diphenylmethane series, MDA). The expression "isocyanate composition" also encompasses embodiments in which two or more different isocyanates (e.g. mixtures of MDI and TDI) have been used in the preparation of the polyurethane material. This also applies within one isocyanate class (that is to say, for example, also applies to various MDI types). Also, further isocyanates such as hexamethylene diisocyanate (HDI) and its oligomers or naphthylene diisocyanate (NDI) may be present. The totality of all isocyanates used in the preparation of the polyurethane material is referred to as the isocyanate composition (of the polyurethane material). The isocyanate composition comprises at least one isocyanate.

[0084] The conversion according to step (g) may for example be achieved by phosgenation or also by phosgene-free conversion. Suitable processes are for example liquid phosgenation, gas-phase phosgenation or gas-liquid phosgenation or a phosgenation via salt or a phosgene-free conversion for example carbamate cleavage. Suitable conditions for the phosgenation are in principle known to the person skilled in the art and are for example disclosed in Ullmann's Encyclopedia of Industrial Chemistry, 7th ed. Vol. 20, 2012, p. 63-82, WO 99 / 54289 A, WO 2004 / 056756 A (liquid phosgenation); Ullmann's Encyclopedia of Industrial Chemistry, 4th ed. Vol. 13, 2012, p. 353, DE 25 870847 A, EP 1532107 A, EP 0570799 A EP 0289840 A (gasphase phosgenation); or EP 2044009 A1, WO 2013 / 060836 A, WO 2013 / 079517 A (gas-liquid phosgenation). An example of gas-liquid phosgenation process is disclosed in WO 2022 / 106716, examples of gas phase phosgenation processes are disclosed in EP 1761483 B1 , EP 2079684 B1 , EP 2188247 B1 , EP 2408738 B1 and EP 2539314 B1 and examples of phosgene-free conversion are disclosed in WO2018 / 185168 and EP 3250 622 B1. Preferably, the phosgenation comprises admixing a solvent to the amine component and stirring, more preferably at a temperature in the range of from 50 to 180 °C, more preferably in the range of from 70 to 140 °C, more preferably in the range of from 80 to 120 °C, obtaining a polyamine mixture; and bringing the polyamine mixture in contact with phosgene in a reactor and heating the obtained mixture to a temperature in the range of from 90 to 140 °C, more preferably in the range of from 110 to 130 °C, obtaining a mixture comprising one or more polyisocyanates.

[0085] The present invention is also directed to the isocyanate composition obtained or obtainable according to the process as disclosed above. Furthermore, the present invention is directed to the use of the isocyanate composition according to the present invention or the isocyanate composition obtained or obtainable according to the process according to the present invention for the preparation of polyurethanes or polyisocyanurates. For example, TDI or MDI produced according to the present invention can be used as isocyanate substance to produce polyurethane materials by reacting it with a polyol obtained according to the present invention or any other suited polyol component.

[0086] In embodiments, in which the recycled amine substance obtained by the process according to the present invention can be phosgenated together with virgin MDA or TDA to achieve virgin like isocyanates which can be utilized to produce polyurethane materials.

[0087] The produced polyurethane material can in any suitable polyurethane application, preferably in the same application. The polyurethane material can for example be used in mattresses, furniture parts or car seats (primarily TDI) or in appliance or construction applications (primarily pMDI).

[0088] Brief description of the figures:

[0089] Figure 1 : shows the temperature / pressure curve of the depolymerization reaction with n-Butylamine for example 3

[0090] Figure 2: shows the temperature / pressure curve of the depolymerization reaction with Aniline for example 4

[0091] Further embodiments of the present invention can be found in the claims and the examples. It will be appreciated that the features of the subject matter / processes / uses according to the invention that are mentioned above and elucidated below are usable not only in the combination specified in each case but also in other combinations without departing from the scope of the invention. For example, the combination of a preferred feature with a particularly preferred feature or of a feature not characterized further with a particularly preferred feature etc. is thus also encompassed implicitly even if this combination is not mentioned explicitly. Illustrative embodiments of the present invention are listed below, but these do not restrict the present invention. In particular, the present invention also encompasses those embodiments which result from the dependency references and hence combinations specified hereinafter.

[0092] 1 . A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate foam which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and a monofunctional primary or secondary amine as catalyst (CA), and optionally adding a solvent which has a miscibility gap with water, c) addition of an inorganic basic component to cleave eventually formed ammonium salts, d) separation of the amine component derived from material cleavage and the polyol components obtained in step c), in an amine rich and an amine poor phase e) addition of an acidic component to the amine poor phase, to acidify the formed carboxylates of the weak acids f) treatment of the polyol components in the amine poor phase to form a polyol (P2).

[0093] 2. The process according to embodiment 1 , wherein the process further comprises step g) g) phosgenation of the amine component to obtain an isocyanate composition.

[0094] 3. A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and a monofunctional primary or secondary amine as catalyst (CA), and optionally adding a solvent which has a miscibility gap with water, c) addition of an inorganic basic component to cleave eventually formed ammonium salts, d) separation of the amine component derived from material cleavage and the polyol components obtained in step c), in an amine rich and an amine poor phase e) addition of an acidic component to the amine poor phase, to acidify the formed carboxylates of the weak acids f) treatment of the polyol components in the amine poor phase to form a polyol (P2), g) phosgenation of the amine component to obtain an isocyanate composition. The process according to any one of embodiments 1 to 3, wherein the process comprises further purification steps. The process according to any one of embodiments 1 to 4, wherein the process further comprises a step b2) b2) removal of particulate solids from the reaction mixture. A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and a monofunctional primary or secondary amine as catalyst (CA), and optionally a solvent which has a miscibility gap with water, b2) removal of particulate solids from the reaction mixture, c) addition of an inorganic basic component to cleave eventually formed ammonium salts, d) separation of the amine component derived from material cleavage and the polyol components obtained in step c), in an amine rich and an amine poor phase e) addition of an acidic component to the amine poor phase, to acidify the formed carboxylates of the weak acids f) treatment of the polyol components in the amine poor phase to form a polyol (P2), g) phosgenation of the amine component to obtain an isocyanate composition. The process according embodiment 6, wherein carbon dioxide released in the process is used as carbon building block for chemical processes, preferably for the preparation of urea, soda, carbon monoxide. The process according to any one of embodiments 1 to 7, wherein the polyurethane materials are selected from the group consisting of polyisocyanate derived polyurethane materials. The process according to any one of embodiments 1 to 8, wherein the aromatic amine is selected from the group consisting of aniline and toluidine Polyol composition obtained or obtainable according to the process of any one of embodiments 1 to 9. Polyol composition obtained or obtainable according to a process for recycling of polyurethane or polyisocy- anurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and a monofunctional primary or secondary amine as catalyst (CA), and optionally a solvent which has a miscibility gap with water, c) addition of an inorganic basic component to cleave eventually formed ammonium salts, d) separation of the amine component derived from material cleavage and the polyol components obtained in step c), in an amine rich and an amine poor phase e) addition of an acidic component to the amine poor phase, to acidify the formed carboxylates of the weak acids f) treatment of the polyol components in the amine poor phase to form a polyol (P2). Use of the polyol composition according to embodiment 10 or 11 or a polyol composition obtained or obtainable according to the process of any one of embodiments 1 to 8 for the preparation of polyurethanes or polyiso- cyanurates. 13. Isocyanate composition obtained or obtainable according to the process according to any one of embodiments 1 to 9.

[0095] 14. Use of the isocyanate composition according to embodiment 13 or an isocyanate composition obtained or obtainable according to the process of any one of embodiments 1 to 9 for the preparation of polyurethanes or polyisocyanurates.

[0096] The present invention can be further explained and illustrated on the basis of the following examples. However, it will be understood that these examples are included merely for purposes of illustration and are not intended to limit the scope of the invention in any way.

[0097] Examples

[0098] I. Explanation of terms

[0099] PU flexible foam consists of TDI (Toluenediisocyanate, isomers: 2,4 TDI and 2,6 TDI) and long chain Polyether polyols (Polyol 1). The foam contains foaming catalysts, a blowing agent and stabilizers as well.

[0100] End of life (EoL foam) flexible PU foam was sorted by a spectroscopic method to minimize the content of high resilience (HR) polyols and styrene acrylonitrile resin (SAN) polymer particles.

[0101] PU rigid foam consists of polymeric isocyanate (pMDI) and polyether and / or polyester polyols. The foam contains foaming catalysts, blowing agents and stabilizers as well.

[0102] II. Materials used

[0103] Polyol 1 : polyester-polyols containing predominately terephthalic acid, fatty acids, di- or trifunctional glycols and short chain polyether polyols (M = 350 g / mol), the OH number is about 245 mg / g.

[0104] Polyol 2: Polyester polyol based phthalic acid, diethylene glycol and monoethylene glycol, the OH number is about 240 mg / g.

[0105] Isocyanate 1 : polymeric isocyanate (pMDI-1) with a typical NCO content of 31.5 g / 100g and a viscosity at 25°C of about 550 mPas, commercially available product from BASF.

[0106] III. Analytical methods a) High performance liquid-chromatography (HPLC): HPLC analyses was carried out to determine TDA and 2,2-, 2,4-, 4,4-MDA, 3-ring MDA, 4-ring MDA, and 5-ring MDA.

[0107] HPLC-setup: Agilent Technologies "1200 Series”

[0108] Column: Fluofix (5 pm, 250 x 4.6 mm)

[0109] Detection: 205 nm

[0110] Temperature: 25°C

[0111] Injection volume: 10 pL

[0112] Mobile phase: (A)1000 mL water + 1 ml H3PO4, (B) 950 mL Acetonitrile + 50 mL water + 1 mL H3PO4 b) GC-analysis: Quantification of 2,2-, 2,4-, 4,4-MDA. The detailed description of the GO method is listed below:

[0113] GC-setup: Agilent 7890A

[0114] Column: DB-5HT (30m x 0,32mm x 0,1 pm)

[0115] Temperature program: 80oC-5min-6°C / min-370°C-30min

[0116] Injection temperature: 340°C

[0117] Injection volume: 1 pL

[0118] Detector temperature: 340°C

[0119] Carrier gas : Hydrogen (Constant Pressure 10psi)

[0120] Split ratio: 15:1 c) Amine number estimation

[0121] Amine number titration is carried out according to DIN 53176. The amine number was utilized to calculate the amount of pMDA. Thereof the theoretical amine number of hydrolyzed isocyanate 1 was estimated.

[0122] Based on the NCO number of isocyanate 1 the amount of amine groups was calculated under the assumption that each mol NCO is transformed to an amine group. The theoretical value of the amine number of hydrolyzed isocyanate 1 is between 500 and 510 mg / g KOH. d). Silicium, Phosphorus analyses

[0123] Silcium and phosphorus determination were carried out to quantify the amount silicon stabilizers and flame retardant (phosphorus ester) in the different fractions. The analyses were done via atomic absorption spectrometry (AAS). e) Elementary analysis of Carbon, Nitrogen, Oxygen and Hydrogen IV. Examples

[0124] 1 . Model foam

[0125] 1.1 Rigid foams (MF1)

[0126] PIR-construction foam: Hydroaminolysis of a foam synthesized from isocyanate 1 , polyols and different additives like e. g. catalysts, surfactants, blowing agents re-quired for foaming (71.4 wt.-% isocyanate 1 ; 18.4 wt- % polyols primarily polyol 1 and 2 containing predominately aromatic dicarboxylic acids, like phthalic acid and terephthalic acid and short-chain polyether polyols)

[0127] Surfactants: Silicone oils

[0128] Blowing agents: Water, Cyclopentane

[0129] Catalysts: Tertiary amines and potassium salts

[0130] 2. EoL / lndustrial production waste

[0131] 2.1 PU rigid foam (EF1)

[0132] Foam based on isocyanate 2 and a mixture of polyols similar to polyol 2 and 3

[0133] Additives and impurities: Foaming catalysts, stabilizers, metals, inorganic salts

[0134] 3. Example 1 : Flame retardant (TCPP) extraction of PIR foam

[0135] 30 g milled foam was mixed with the extraction medias (toluene, chlorobenzene, 850 g). The mixture was stirred and heated up to the boiling temperature of the extraction media. The extraction time was 16 h. After 16 h the mixture was cooled down to room temperature and filtrated. The foam was washed several times with extraction media. The filtrate was concentrated via vacuum evaporation. The phosphorus mass balance was between 95 -105 %.

[0136] 4. Example 2: Model-PIR foam (MF1) cleavage via KOH

[0137] 4 g of the milled model foam, 40 g water and 0.4 g KOH(aq) (50 wt.-%) were charged to a stirred autoclave. The hydrolysis reaction was done at 200 °C and approximately 15 bar (mixture water / pMDA and the emitted CO2) for 12 h. After the reaction the autoclave was cooled down and the remaining pressure was released. After opening the autoclave still not cleaved foam particles were visible. Example 3: Model-PIR-foam (MF 1) cleavage with n-butylamine as catalyst

[0138] 7 g of the milled model foam, 70 g water, 40 g toluene and 15 g n-butylamine were charged to a stirred autoclave (300 mL). The hydrolysis reaction was done at 220 °C and approximately 30 bars for 8 h. After the reaction the autoclave was cooled down and the remaining pressure was released. After stirring the mixture was cooled down to room temperature and was flushed several times with nitrogen. To determine the conversion of the depolymerization reaction ATR analyses and NMR analyses of the organic phase was carried out.

[0139] Work up: Butylamine was evaporated under vacuum and afterwards a phase separation of the amine rich and the amine poor phase was carried out at 80°C. Toluene of the amine rich phase was removed by evaporation using a rotary evaoporator and the amine number of the residue was analyzed (mresidue = 3.9 g, amine number: 460 mg KOH / g). Based on the results a pMDA yield of 96 % could be calculated.

[0140] The temperature and pressure development of the reaction are shown in figure 1 . Example 4: Model-PIR-foam (MF 1) cleavage via Aniline as catalyst

[0141] 7 g of the milled model foam, 70 g water, and 70 g aniline were charged to a stirred autoclave (300 mL). The hydrolysis reaction was done at 220 °C for 12 h and approximately 25 bar for 8 h. After the reaction the autoclave was cooled down and the remaining pressure was relaxed. After stirring the mixture was cooled down to room temperature and was flushed several times with nitrogen. To evaluate the conversion of the depolymerization reaction ATR analyses and NMR analyses of the organic phase was carried out.

[0142] A phase separation of the aniline rich and the amine poor phase was carried out at 80°C. Aniline was evaporated. Toluene of the amine rich phase was evaporated, and the amine number was analyzed of the residue (mresidue = 4.1 g, amine number: 470 mg KOH / g). Based on the results a pMDA yield of 105 % could be calculated. The higher yield is a result of a not fully evaporated aniline content.

[0143] The temperature and pressure development of the reaction are shown in figure 2. Example 5: Phase separation after cleavage with sodium salts of diacids (Resalting process) (model system)

[0144] 1.8 g Phthalic acid and 1.7 g terephthalic acid were filled into a round flask. 200 g water, 200 g Chlorobenzene and 1.9 g solid NaOH were added to the round flask. The mixture was heated to 80°C and stirred for 30 min. Afterwards the mixture was separated in a funnel at 80°C. The organic solvent and the water were evaporated under vacuum from the respective phases. No residue remaining from the organic phase was found. The mass of the residue remaining from the aqueous phase was 4.6 g (mtheoreticai, sodium salts 4.4 g). 8. Example 6: pMDA hydrochloride extraction of the amine rich phase (derived from depolymerization of MF 1) as purification step

[0145] 47g of amine rich phase residue derived from foam 1, 170 g 32 wt.-% aqueous HCI, 380g water and 500 g toluene were mixed and heated to 85°C. The mixture was stirred for 1 h and then a phase separation took place. Table 2 summarizes the results. Approximately 45 g pMDA as hydrochloride (63.5 g pMDA*HCL) were obtained.

[0146] Table 1: Results of the pMDA purification step with aqueous HCI.

[0147] Literature cited

[0148] WO 2021 / 023889 A

[0149] WO2023 / 208946

[0150] US 9,023,907 B2

[0151] WO 2015 / 121057

[0152] WO 2013 / 139781

[0153] "Kunststoffhandbuch [Plastics handbook], volume 7, Polyurethane [Polyurethanes]", Carl Hanser Verlag, 3rd edition 1993, chapter 3.1, 3.2 and 3.3.2

[0154] WO 2006 / 034800

[0155] EP 0090444

[0156] WO 2005 / 090440

[0157] EP 22205386.0

[0158] EP22178796.3

[0159] EP22178797.1

[0160] DE2854940A1

[0161] Ullmann's Encyclopedia of Industrial Chemistry, 7th ed. Vol. 20, 2012, p. 63-82

[0162] WO 99 / 54289 A

[0163] WO 2004 / 056756 A

[0164] Ullmann's Encyclopedia of Industrial Chemistry, 4th ed. Vol. 13, 2012, p. 353

[0165] DE 25 870847 A

[0166] EP 1532107 A

[0167] EP 0570799 A

[0168] EP 0289840 A EP 2044009 A1

[0169] WO 2013 / 060836 A

[0170] WO 2013 / 079517 A

[0171] WO 2022 / 106716 EP 1761483 B1

[0172] EP 2079684 B1

[0173] EP 2188247 B1

[0174] EP 2408738 B1

[0175] EP 2539314 B1 WO2018 / 185168

[0176] EP 3250 622 B1

Claims

Claims1 . A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and a monofunctional primary or secondary amine as catalyst (CA), and optionally adding a solvent which has a miscibility gap with water c) addition of an inorganic basic component to cleave eventually formed ammonium salts, d) separation of the amine component derived from depolymerization and the polyol components or polyol fragments obtained in step c), in an amine rich and an amine poor phase e) addition of an acidic component to the amine poor phase, to acidify the formed carboxylates of the weak acids f) treatment of the polyol components in the amine poor phase to form a polyol (P2).

2. The process according to claim 1 , wherein the monofunctional primary or secondary amine are selected from the group consisting of aliphatic and / or aromatic amines in a molar range from 31 g / mol to 186 g / mol3. The process according to claim 1 or 2, wherein the process further comprises step g) g) phosgenation of the amine component to obtain an isocyanate composition.

4. The process according to any one of claims 1 to 3, wherein the process comprises further purification steps.

5. The process according to any one of claims 1 to 4, wherein the process further comprises a step b2) b2) removal of particulate solids from the reaction mixture.

6. The process according claim 5, wherein carbon dioxide released in the process is used as carbon building block for chemical processes, preferably for the preparation of urea, soda, carbon monoxide7. The process according to any one of claims 1 to 6, wherein the polyurethane materials are selected from the group consisting of polyisocyanate derived polyurethane materials.

8. Polyol composition obtained or obtainable according to the process of any one of claims 1 to 7.

9. Use of the polyol composition according to claim 8 or a polyol composition obtained or obtainable according to the process of any one of claims 1 to 7 for the preparation of polyurethanes or polyisocyanurates.

10. Isocyanate composition obtained or obtainable according to the process according to any one of claims 1 to 7.11 . Use of the isocyanate composition according to claim 10 or an isocyanate composition obtained or obtainable according to the process of any one of claims 1 to 7 for the preparation of polyurethanes or polyisocyanurates.