Recycling of pu-softfoams with graft polyol content

Abstract

The present invention relates to a process for recycling of graft polyol containing polyurethane containing waste comprising the steps of providing a composition comprising a comminuted pol- yurethane material which comprises a graft polyol; depolymerization of the comminuted polyure- thane by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the con- tent of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture; adjusting the water content to achieve phase separation; separation of the amine com- ponent and the polyol components to amine rich and an amine poor phase. 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 for the preparation of polyurethanes.

Description

[0001] Recycling of PU-softfoams with graft polyol content

[0002] The present invention relates to a process for recycling of graft polyol containing polyurethane containing waste comprising the steps of providing a composition comprising a comminuted polyurethane material which comprises a graft polyol; depolymerization of the comminuted polyurethane by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture; adjusting the water content to achieve phase separation; separation of the amine component and the polyol components to amine rich and an amine poor phase. 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 for the preparation of polyurethanes.

[0003] The recycling of waste streams represents an essential building block for achieving greater sustainability of existing value chains. In material cycles of plastics, remonomerizations as recycling techniques are those with the greatest circularity. In the field of plastics, polyurethane plastics are a large-volume group. Polyurethanes are formally prepared by polyaddition of at least one polyol with at least one polyisocyanate.

[0004] One remonomerization strategy discussed in the literature and in patents, among others, is hydroglycolysis, in which an initially formed carbamate is subsequently hydrolyzed to the corresponding amine with carbon dioxide evolution. The process can be carried out in one or two steps. Numerous basic amines, alkali metal and alkaline earth metal hydroxides are disclosed in the literature as catalysts for hydroglycolysis.

[0005] CN 106700126 discloses a method for self-catalytic degradation and recycling of polyurethane foams. The process is applied for the recycling of polyurethane waste material.

[0006] US20010027246 discloses a method of recovering a decomposition product from a polyurethane, the method comprising the steps of thermally decomposing a polyurethane into a liquid containing a polyol and a urea compound which is soluble in the polyol, and solids containing a urea compound which is insoluble in the liquid in the presence of a polyamine compound at a temperature of 120 to 250°C; removing the solids; hydrolyzing the residue with water retained at a high temperature of 200 to 320°C and a high pressure; and recovering the resulting polyamine and / or polyol.

[0007] EP 1 142 945 A2 relates to a method of chemically decomposing the cuttings made in molding or fabricating articles of polyurethane resins and waste of such resin articles for industrially advantageous recovery of a polyamine compound and a polyol compound useful as the raw materials of the polyurethane resin. According to CN 1275587 a polyurethane waste material is decomposed in aqueous solution, and the catalyst is separated in the water-phase so as to be used cyclically. The decomposed product polyether and toluene diamine can be separated in water.

[0008] Polyurethane materials, in particular foams, such as in particular soft foams used in mattresses and furniture can contain graft polyols which are typically SAN-particles grafted with polyetherols. These graft polyols hinder the phase separation in recycling processes and significantly slow down any filtration processes, which make downstream processing technically very difficult. The circularity of the catalyst is also no longer given.

[0009] Accordingly, it was an object to provide a process for recycling polyurethane-containing waste streams which also comprise graft polyol containing polyurethane in such a way that maximum yields of polyols and amine monomers can be achieved while simplifying technical workup and ensuring the circularity of the catalyst.

[0010] According to the present invention, this object is solved by a process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane material which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase.

[0011] It was surprisingly found that using the specific sequence of reaction steps according to the present invention results in the cleavage of the stabilizer polyol i.e. the macromer in the graft polyol synthesis and the adjustment of the water leads to phase separation. Therefore, the process allows to remonomerize graft polyol containing polyurethanes in an efficient manner.

[0012] It has been found that the process is particularly suitable for the recycling and remonomeriza- tion of polyurethane foams. Thus, according to the present invention, the polyurethane material preferably is a polyurethane foam, in particular a flexible polyurethane foam.

[0013] In the context of the present invention, a polyurethane material which comprises a graft polyol is understood to be a polyurethane material which comprises an amount of graft polyol which is typical for polyurethane materials, preferably is in the range of from 2.5 % to 30 % by weight of the polyurethane material, in particular in the range of from 5 % to 30 % by weight of the polyurethane material, more preferable in the range of from 7.5 % to 30 % by weight of the polyurethane material.

[0014] The process according to the present invention comprises steps a), b), optionally c), and d) but may comprise further steps. It has been found that the specific sequence of process steps according to the present invention allow to recover polyols and isocyanates from polyurethane material which comprises a graft polyol in high quality in a simple manner.

[0015] According to the process of the present invention, it is possible to recover both starting material components from the polyurethane. The polyurethane components are either recovered directly, for example the polyols, or are obtained as valuable synthesis building blocks such as di- or polyfunctional aromatic amines which may readily be converted to polyisocyanates.

[0016] According to step a), a composition comprising a comminuted polyurethane material which comprises a graft polyol is provided.

[0017] The term “graft polyols” used according to the invention, often also termed polymer polyols, means dispersions of polymers, mostly acrylonitrile-styrene copolymers stabilized by the copolymerization of macromers, in a polyether polyol matrix. The graft polyols used for the preparation of polyurethane materials usually have a hydroxy value in the range from 15 to 120 mg KOH / g. They may be present in the polyurethane materials in an amount of up to 25 wt.%.

[0018] In the context of the present invention, a “comminuted polyurethane material” means the material is obtained from a material and the comminuted polyurethane is for example used in shredded form, in the form of granules, flakes, as an agglomerate, or as a powder. The polyurethane materials can be comminuted by conventional methods, for example by shredding, e.g. in a rotation 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 or ground, e.g. by known cold grinding processes.

[0019] The properties of the polyurethane materials might vary in broad ranges, for example the content of the graft polyols present in the polyurethane material may vary. In principle, also polyurethane materials containing no graft polyols may be used according to the present invention. According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the comminuted polyurethane material comprises a mixture of different polyurethane materials which may for example vary in the content of the graft polyol present

[0020] The polyurethane 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. Suitable methods are in principle known to the person skilled in the art.

[0021] Furthermore, the process may comprise sorting steps based on optical methods, for example based on NIR spectroscopy. Sorting based on optical methods may for example be used in the process to determine the graft polyol content of the polyurethane material. Preferably, the process may also comprise steps to adjust the graft polyol content of a mixture in a predetermined range.

[0022] 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.

[0023] 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. For the preparation of graft polyol containing polyurethane materials, graft polyols are used in the polyol component.

[0024] The properties of a polyurethane material are influenced by the chemistry of polyisocyanate and polyol components used and the recipe applied in polymerisation. For example, the starting materials may influence the crosslinking density of the polymers in a three-dimensional network.

[0025] Slab flexible polyurethane foams are typically obtained from TDI and polyetherpolyols with a OH number of 35 to 70 mgKOH / g and a functionality of 2.5-3.5 creating a medium crosslinked network.

[0026] Industrially and consequently in large quantities, especially tolylene 2,4 and 2,6-diisocyanate (TDI) or methylenedi(phenylisocyanate) (MDI) or its polymeric forms or are used as polyisocyanate components for the production of PU flexible foams and PU rigid foams. For a representative composition of these PU foams, see for example US 9,023,907 B2, WO 2015 / 121057 and WO 2013 / 139781.

[0027] Organic polyisocyanates that can be used in the preparation of polyurethanes, preferably for flexible foams, 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. Suitable polyisocyanate components used for the production of the polyurethanes or polyisocy- anurates comprise any of the polyisocyanates known for the production of polyurethanes or pol- yisocyanurates. 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’-diisocyanate, 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 (N DI), and mixtures thereof. Preferably, tolylene 2,4- and 2,6-diisocyanate (TDI) is used.

[0028] Preferably, tolylene 2,4- and / or 2,6-diisocynate (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 are used. 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.

[0029] The organic and polyisocyanates may be used individually or in the form of mixtures.

[0030] Common polyols used in huge quantities are, e.g., selected from the group consisting of polyether polyols, polyester polyols, polyetherester polyols and mixtures thereof, preferably polyether polyols.

[0031] 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-ac- tivity, for example aliphatic alcohols, phenols, amines, carboxylic acids, water, or compounds based on natural substances, for example glycerol, sucrose, 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.

[0032] 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.

[0033] According to step b) the comminuted polyurethane provided in step a) is depolymerized by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture. Preferably, the depolymerization is achieved by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis according to the present invention. The process of the present invention can optionally comprise an alcoholising, ammonolysing or aminolysing step, in combination with a hydrolysing step, in which a polyurethane material is contacted with a suitable substance containing OH or NH groups substance. During alcoholising, ammonolysing or aminolysing of the polyurethane material in the presence of water, a mixture containing a polyol substance and an amine substance is formed. According to a preferred aspect of the present invention, the polyurethane material is contacted with the alcoholising substance and water. Due to the addition of water or due to water being present in the original polyurethane material, a hydrolysis of the polyurethane material occurs. According to the present invention, the hydrolyzing step and the al- coholysing, ammonolysing or aminolysing step may be performed separately or may be combined. Typically, the amine corresponding to the isocyanate component used in the PU material is obtained by applying depolymerization processes comprising a hydrolysis step optionally together or after applying a e.g. alcoholysis, ammonolysis, aminolysis.

[0034] According to a further embodiment, the present invention is directed to the process as disclosed above, wherein depolymerization according to step b) is carried out by a process comprising a hydrolysis step together with applying an alcoholysis, ammonolysis, or aminolysis.

[0035] In case the polyurethane material already contains water, it is possible that no water needs to be added in order to adjust the water content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture. In case, the original water content of the polyurethane material is not in the described range, a suitable amount of water can be added. The water content in the reaction mixture preferably is in the range of from 4 to 15 wt.-% based on the reaction mixture.

[0036] For an optimized yield of the release of raw materials, preferably step b) is performed in the presence of a catalyst, wherein preferably the catalyst is selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal salts of carboxylic acids, in particular acetates, alkaline earth metal salts of carboxylic acids, in particular acetates, Lewis acids, in particular dibutyltin dilaurate, organic amines, in particular imidazole or diethanolamine, or aromatic amines such as aniline, toluenediamine or methylenedi(phenylamine), organometallic compounds, in particular rare earth metal catalysts, for example titanium tetrabutoxide, or tin compounds, such as tin octoate. As alkali metal hydroxides, the use of potassium hydroxide (KOH), sodium hydroxide (NaOH), or cesium hydroxide (CsOH) is particularly preferred. Suitable catalyst are for example disclosed in WO 2022 / 171586 or US 2022 / 0251328.

[0037] In accordance with a preferred embodiment, the catalyst, for example potassium hydroxide or sodium hydroxide, is used in an amount of about 0.2 wt.-% or more and / or about 5 wt.-% or less. In the context of the present invention, preferably the corresponding amine of an isocyanate used in the process or present in one of the components may be used as a catalyst. In accordance with another preferred embodiment, the catalyst, for example 2,4 toluenediamine and / or 2,6 toluenediamine (TDA) or a mixture thereof, is used in an amount of about 1 wt.-% or more and / or about 20 wt.-% or less.

[0038] As alcoholising substance, preferably an alcohol is used. For example, the alcoholising substance comprises or consists of one or more of the following: methanol, ethanol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methylene glycol, triethylene glycol, glycerol, 2-methyl-1 ,3-propanediol and mixtures of two or more thereof. As aminolising substance, preferably an amine is used such as ethylamine , diaminoethan or diaminopropan.

[0039] For alcoholising or aminolising the polyurethane material, preferably about 0.25 wt. parts or more and / or about 5 wt. parts or less alcoholising substance or aminolising substance per wt. part polyurethane material, are used. Suitable processes are in principle known to the person skilled in the art.

[0040] Preferably, it is possible to recover both starting material components from the polyurethane. Typically, the isocyanate component or an isocyanate precursor like an amine, carbamate or urea is obtained and can be separated but also the polyol componentt is separated. Usually, the depolymerization results in a mixture of components which might be separated using suitable separation techniques. The process of the present invention thus may also comprise further separation steps.

[0041] 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., toluenediamines (TDA), in particular 2,4 toluenediamine or 2,6-toluene- diamine, methylene diphenyl diamines (MDA), oligomeric and polymeric methylene phenylene amine, hexamethylene diamine (HDA), or naphthylene diamine (NDA). The commonly used polyols as described above preferably also can be re-isolated. Thus, the process preferably further yields, e.g., polyetherpolyols with a molecular weight in the range of from 2000 to 5000 g / mol, in particular in the range of from 2500 to 4000 g / mol and an OH number in the range of from 25 to 800 mgKOH / g, in particular from 25 to 500 mgKOH / g, preferably from 25 to 70 mgKOH / g, more preferable from 30 to 70 mgKOH / g Preferably, the polyol substance comprises or consists of one or more polyols having a molecular weight of about 2500 to about 4000 g / mole, a nominal functionality of from 1 to 6, preferably between 1 to 4.5 is used, in particular in the range of from 1 to 4.1 , more preferable in the range of from 1 to 3.9, most preferable in the range of from 1.1 to 3.5.

[0042] According to the present invention, depolymerization is preferably achieved using suitable temperatures and adjusting temperature and water content. Typically, the alcohol, in particular the glycol, and a catalyst, e.g. the to the isocyanate corresponding amine are charged in a reactor and the material is then added at elevated temperatures in the range of from 140°C to 250°C,. Typically, water is then added resulting in a decrease of the temperature at atmospheric pressure with no pressure build-up. Typically, depolymerization to cleave the graft polyols is started at a temperature in the range of from 100 to 150°C . It is possible to adjust the water content and / or the temperature to complete the depolymerization. It is for example possible to increase the reaction temperature by adjusting the water content, in particular by reducing the water content. According to a further embodiment the reaction may also be carried out in a pressure reactor. In this case, the reaction can take place with the high water content at higher temperatures, in accordance to this invention. After the depolymerization, typically a mixture of reaction products is obtained.

[0043] The process of the present invention optionally comprises step c). According to step c) of the process of the present invention, the water content is adjusted to achieve phase separation. The water content may be adjusted by reducing the water content. Preferably, the water content is adjusted to an amount of 0.1 to 1 wt.-% based on the weight of the reaction mixture. 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.

[0044] According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein step c) is carried out and the water content is adjusted in a range of from 0.1 to 1 wt.-% based on the reaction mixture.

[0045] 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, or waste materials prior to a separation of the amine component and the polyol components.

[0046] Preferably, the process further comprises allowing the mixture to settle, wherein one or more phases are formed. 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.

[0047] According to step d) of the process according to the present invention, the amine component and the polyol components obtained in step b) or step c) are separated to amine rich and an amine poor phase. 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.

[0048] According to a preferred embodiment, a phase separation is performed after the mixture has settled. Preferably, the phase separation is performed in a phase separation device. For improved phase separation, it can be beneficial to remove water included in the mixture, e.g., by flash evaporation. Water removal can also be done by applying vacuum to the mixture or simply distill the mixture at atmospheric pressure. In principle, phase separation might also be improved by addition of salt or by using specific internals in phase separation devices. Suitable methods are in principle known to the person skilled in the art.

[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 evaporation of the phase in one or more evaporators, contacting the phase with an ion exchange material; contacting the phase with one or more adsorbents.

[0050] 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.

[0051] In the alternative or additionally, centrifugation is a preferred solid-liquid-separation method.

[0052] According to the present invention, the process may comprise further separation steps, purification steps or sorting steps. It is for example possible to remove components such as for example flame retardants from the comminuted polyurethane or polyisocyanurate material by suitable methods such as for example extraction. Other extractable components are other and sometimes even solid additives. The flame retardants may also be purified and reused. Furthermore, it is possible to sort the comminuted polyurethane, for example sort it by the chemical nature of the components used or by the content of additives. Sorting might for example by conducted using optical methods such as for example NIR spectroscopy.

[0053] 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 ) and / or step a2) a1 ) sorting of the materials using optical methods, in particular NIR spectroscopy; a2) at least partial extraction of flame retardants from the the comminuted polyurethane or polyisocyanurate material.

[0054] Suitable conditions for step a1) are for example disclosed in EP 22205386.0. Further separation steps may be carried out according to the resent invention to separate off further byproducts.

[0055] In work-up by distillation, compounds are separated according to their volatility, with more volatile compounds being separated first. Additives, water 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.

[0056] 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.

[0057] 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.

[0058] According to one aspect of the invention, it can be beneficial, if the one or more adsorbents are added before the solids are removed. For example, the one or more adsorbents can serve as a filtering aid.

[0059] According to one aspect of the invention, the mixture is contacted with one or more adsorbents before allowing the mixture to settle, wherein preferably the one or more adsorbents are selected from the group consisting of: activated carbon, silica, silicate, in particular alkali metal silicate and / or alkaline earth metal silicate, for example magnesium silicate, or a mixture of two or more thereof. Particularly preferred is the use of silicate, for example magnesium silicate and / or sodium silicate, as adsorbent before the phase separation.

[0060] According to one aspect of the invention, the phase, which is polyol substance rich, is purified by performing a solid-liquid separation, in which solids are removed, before the purification, wherein the solid-liquid-separation comprises one or more of the following: filtration, centrifugation, decantation.

[0061] Preferably, the work-up of the mixture results in a partial or essentially complete release and / or recovery of the alcoholising substance or the aminolising substance.

[0062] Alternatively, the polyol components may be recovered by extraction from the depolymerization mixture using a suitable extractant or a pair of extractants.

[0063] Further, in particular for recovering the polyol components, 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:

[0064] - filtration - centrifugation,

[0065] - decantation;

[0066] - extraction;

[0067] - distillation;

[0068] - full or partial evaporation of the phase in one or more evaporators;

[0069] - contacting the phase with an ion exchange material;

[0070] - contacting the phase with one or more adsorbents.

[0071] 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.

[0072] It is understood that the separation and purification process described above can be combined with any of the various embodiments of the inventive process described herein.

[0073] The process according to the present invention comprises steps a), b), c) and d) 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 as disclosed above.

[0074] 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). 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) or that step d) is carried out directly after step c).

[0075] 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.

[0076] After the work-up, the phase, which is polyol substance rich, preferably an acid number of 0.1 mg KOH / g or less. The acid number (corresponding to the acid value) is determined according to DIN EN ISO 4629-2, with minor changes. A mixture of iso-propanol / water 1 :1 was used as solvent mixture, instead of toluene / ethanol 2:1 . As a further change, NaOH / KOH was dissolved in methanol instead of ethanol.

[0077] Preferably, the process further comprises work-up of the mixture by purification of the amine substance, for example including distillation, extraction, adsorption, precipitation or crystallization in order to purify the amine substance. It is understood that the separation process described above can be combined with any of the various embodiments of the inventive process described herein.

[0078] With the process of the present invention, about 90 % or more, preferably about 97 % or more, of the polyol substance which is theoretically recoverable from the polyurethane material can be released. Thus, the yield of the polyol substances or monomer fragments of those which are released is about 50 % or more, preferably of 60 wt.-% or more, in particular of 75 wt.-% or more.

[0079] According to a further aspect, the present invention is also directed to the polyol composition obtained or obtainable according to the process as disclosed above. The polyol composition obtained typically also comprises polyols of the graft polyol.

[0080] 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 polyiso- cyanurate containing polyurethane materials.

[0081] 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.

[0082] 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 polyisocyanu- rates.

[0083] 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. The polyol substance may also be used in a mixture comprising further polyols.

[0084] The produced polyurethane material can be used in any suitable polyurethane application also in the preparation of thermoplastic polyurethanses, preferably in the same application. The polyurethane material can for example preferably be used in mattresses, furniture parts or car seats or also in appliance or construction applications or in automotive parts such as dash boards, steering wheel, bumpers, in consumer goods like casual, sport or safety shoes.

[0085] According to the present invention, also the amine substance may be recovered. Thus, the invention also 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 the polyol also apply for the process for producing an isocyanate substance. 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. 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 NDL Suitable conditions for the phosgenation are in principle known to the person skilled in the art.

[0086] According to a further embodiment, the present invention therefore is also directed to the process as disclosed above, wherein the process further comprises step e) e) conversion of the amine component to obtain an isocyanate composition.

[0087] 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.

[0088] The conversion according to step (viii) may for example be achieved by phosgenation or also by phosgene-free conversion. Suitable processes are for example liquid phosgenation, gasphase 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, 7thed. Vol. 20, 2012, p. 63-82, WO 99 / 54289 A, WO 2004 / 056756 A (liquid phosgenation); Ullmann’s Encyclopedia of Industrial Chemistry, 4thed. 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 3 250 622 B1.

[0089] 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.

[0090] 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. For example, TDI or MDI produced according to the present invention can be used as isocyanate substance to produce polyurethane material by reacting it with a polyol obtained according to the present invention or any other suited polyol component.

[0091] 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.

[0092] The produced polyurethane material can be used 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 (TDI) or in appliance or construction applications (primarily pMDI).

[0093] 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.

[0094] 1 . A process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane foam which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase.

[0095] 2. The process according to embodiment 1 , wherein depolymerization according to step b) is carried out by a process comprising a hydrolysis step together with applying an alcoholysis, ammonolysis, or aminolysis.

[0096] 3. The process according to embodiment 1 or 2, wherein step c) is carried out and the water content is adjusted in a range of from 0.1 to 1 wt.-% based on the reaction mixture.

[0097] 4. The process according to any one of embodiments 1 to 3, wherein the process comprises further purification steps.

[0098] 5. The process according to any one of embodiments 1 to 4, wherein the process further comprises step a1 ) and / or step a2) a1 ) sorting of the foams using optical methods, in particular NIR spectroscopy; a2) at least partial extraction of flame retardants from the comminuted polyurethane foam.

[0099] 6. The process according to any one of embodiments 1 to 5, wherein the process further comprises step e) e) conversion of the amine component to obtain an isocyanate composition.

[0100] 7. A process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane foam which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase, e) conversion of the amine component to obtain an isocyanate composition. Polyol composition obtained or obtainable according to the process of any one of embodiments 1 to 7. Polyol composition obtained or obtainable according to the process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane foam which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase. Use of the polyol composition according to embodiment 8 or 9 or a polyol composition obtained or obtainable according to the process of any one of embodiments 1 to 7 for the preparation of polyurethanes. Isocyanate composition obtained or obtainable according to the process according to any one of embodiments 1 to 7. Isocyanate composition obtained or obtainable according to the process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane foam which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase. Use of the isocyanate composition according to embodiment 11 or 12 or an isocyanate composition obtained or obtainable according to the process of any one of embodiments 1 to 7 for the preparation of polyurethanes. A process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane foam which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase. The process according to embodiment 14, wherein depolymerization according to step b) is carried out by a process comprising a hydrolysis step together with applying an alcoholysis, ammonolysis, or aminolysis. The process according to embodiment 14 or 15, wherein step c) is carried out and the water content is adjusted in a range of from 0.1 to 1 wt.-% based on the reaction mixture. The process according to any one of embodiments 14 to 16, wherein the process comprises further purification steps. The process according to any one of embodiments 14 to 17, wherein the process further comprises step a1 ) and / or step a2) a1 ) sorting of the foams using optical methods, in particular NIR spectroscopy; a2) at least partial extraction of flame retardants from the comminuted polyurethane foam. The process according to any one of embodiments 14 to 18, wherein the process further comprises step e) e) conversion of the amine component to obtain an isocyanate composition. A process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane foam which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase, e) conversion of the amine component to obtain an isocyanate composition. Polyol composition obtained or obtainable according to the process of any one of embodiments 14 to 20. Polyol composition obtained or obtainable according to the process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane foam which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase. Use of the polyol composition according to embodiment 21 or 23 or a polyol composition obtained or obtainable according to the process of any one of embodiments 14 to 20 for the preparation of polyurethanes. Isocyanate composition obtained or obtainable according to the process according to any one of embodiments 14 to 20. 25. Isocyanate composition obtained or obtainable according to the process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane foam which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase.

[0101] 26. Use of the isocyanate composition according to embodiment 24 or 25 or an isocyanate composition obtained or obtainable according to the process of any one of embodiments 14 to 20 for the preparation of polyurethanes.

[0102] 27. A process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane material which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase, wherein the graft polyol content of the polyurethane material is in the range of from 2.5 % to 30 % by weight of the polyurethane material.

[0103] 28. The process according to embodiment 27, wherein depolymerization according to step b) is carried out by a process comprising a hydrolysis step together with applying an alcoholysis, ammonolysis, or aminolysis. 29. The process according to embodiment 27 or 28, wherein step c) is carried out and the water content is adjusted in a range of from 0.1 to 1 wt.-% based on the reaction mixture.

[0104] 30. The process according to any one of embodiments 27 to 29, wherein the process comprises further purification steps.

[0105] 31. The process according to any one of embodiments 27 to 30, wherein the process further comprises step a1 ) and / or step a2) a1) sorting of the materials using optical methods, in particular NIR spectroscopy; a2) at least partial extraction of flame retardants from the comminuted polyurethane material.

[0106] 32. The process according to any one of embodiments 27 to 31 , wherein the process further comprises step e) e) conversion of the amine component to obtain an isocyanate composition.

[0107] 33. Polyol composition obtained or obtainable according to the process of any one of embodiments 27 to 32.

[0108] 34. Use of the polyol composition according to embodiment 33 or a polyol composition obtained or obtainable according to the process of any one of embodiments 27 to 32 for the preparation of polyurethanes.

[0109] 45. Isocyanate composition obtained or obtainable according to the process according to any one of embodiments 27 to 32.

[0110] 46. Use of the isocyanate composition according to embodiment 45 or an isocyanate composition obtained or obtainable according to the process of any one of embodiments 27 to 32 for the preparation of polyurethanes.

[0111] 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.

[0112] EXAMPLES

[0113] In the following, preferred Examples are described in detail: For all of the Examples described below, wt.-% are given with respect to the total weight of the respective mixture, phase etc.

[0114] For the Examples, a polyurethane foam material without SAN was used. For release yield, the following expectation values, i.e. , theoretically obtainable amounts, were used:

[0115] 23 wt.-% toluene diamine, a polyurethane foam material with 15wt.% graft polyol including SAN was used. For release yield, the following expectation values, i.e., theoretically obtainable amounts, were used:

[0116] 23 wt.-% toluene diamine, a end-of-life polyurethane foam material with ~3-5wt.% graft polyol including SAN was used. For release yield, the following expectation values, i.e., theoretically obtainable amounts, were used:

[0117] 21.4 wt.-% toluene diamine, determined via HPLC. Furthermore full conversion was checked via IR.

[0118] The remaining amount is mainly constituted by additives and losses due to carbon dioxide formation during hydrolysis. It is expected that the polyurethane material comprises about 2 mole functional groups per kg (kilogram) polyurethane material. The functional groups in this regard are urethane groups (0.6 mole) and urea groups (1 .4 mole).

[0119] Examples for recycling PU flexible foam with SAN contents > 0.1 wt.%:

[0120] Example 1 : (According to invention)

[0121] A polyurethane foam of known composition with a graft polyol content of 15 wt.% and a polyurethane foam of known composition without SAN were mixed to obtain an overall SAN content of 5wt.%. This foam mixture (50 wt.% of reaction mixture) was dosed in diethylene glycol (41 .8 wt.%) as alcoholising substance in the presence of KOH (solid; 1 wt.%) at 200°C over 15 minutes. 10 minutes after the last foam was added to the reaction mixture, water was added (7.2 wt.%) and everything was stirred, under N2 (or air), and at normal pressure (1013.25 mbar) with a reflux condenser at 130°C for 2 hours. Then water was removed by distillation for 1 h at normal pressure (1013.25 mbar) until the temperature of the reaction mixture has increased to 175°C, when the heating and stirrer were stopped. A phase separation is happening within a couple of minutes.

[0122] The resulting mixture is then cooled to 80°C and kept for 16 h for further phase separation. The second phase (lower phase, diethylene glycol rich) is separated. The composition of the first phase (upper phase, polyol substance rich) includes 64 wt.-% polyol, 25.3 wt.-% diethylene glycol, 9.3 wt.-% toluene diamine, 0.07 wt.-% potassium and 0.7 wt.- % water.

[0123] The composition of the second phase includes 67.4 wt.-% diethylene glycol, 16.1 wt.-% toluene diamine and 1.3 wt.-% potassium.

[0124] Phase separation was successful and the release of 97% of the expected toluene diamine indicates full conversion.

[0125] Example 2: (According to invention)

[0126] A polyurethane foam of known composition with a graft polyol content of 15 wt.% and a polyurethane foam of known composition without SAN were mixed to obtain an overall SAN content of 10wt.%. This foam mixture (50 wt.% of reaction mixture) was dosed in diethylene glycol (41 .3 wt.%) as alcoholising substance in the presence of KOH (solid; 1 ,3 wt.%) at 200°C over 15 minutes. 10 minutes after the last foam was added to the reaction mixture, water was added (7.5 wt.%) and everything was stirred, under N2 (or air), and at normal pressure (1013.25 mbar) with a reflux condenser at 125°C for 2 hours. Then water was removed by distillation for 1 h at normal pressure (1013.25 mbar) until the temperature of the reaction mixture has increased to 180°C, when the heating and stirrer were stopped. A phase separation is happening within a couple of minutes.

[0127] The resulting mixture is then cooled to 80°C and kept for 16 h for further phase separation. The second phase (lower phase, diethylene glycol rich) is separated.

[0128] The first phase (upper phase, polyol substance rich) is further processed by filtration (20pm mesh size).

[0129] The composition of the first phase after filtration includes 68 wt.-% polyol, 21.6 wt.-% diethylene glycol, 9.4 wt.-% toluene diamine 0.19 wt.-% potassium and 0.7 wt.-% water.

[0130] The composition of the second phase includes 57.7 wt.-% diethylene glycol, 14.9 wt.-% toluene diamine, 1 wt.-% potassium and 0.4wt.-% water.

[0131] Phase separation was successful and the release of 97% of the expected toluene diamine indicates full conversion.

[0132] Example 3: (According to invention)

[0133] A sorted mixture of end-of-life polyurethane flexible foams with a graft polyol content of ~3-5 wt.% (according to NIR-measurements; 48 wt.% of reaction mixture) was dosed in diethylene glycol (43.6 wt.%) as alcoholising substance in the presence of KOH (solid; 1 .2 wt.%) at 200°C over 15 minutes. 10 minutes after the last foam was added to the reaction mixture, water was added (7.2 wt.%) and everything was stirred, under N2 (or air), and at normal pressure (1013.25 mbar) with a reflux condenser at 135°C for 2 hours. Then water was removed by distillation for 1 h at normal pressure (1013.25 mbar) until the temperature of the reaction mixture has increased to 190°C, when the heating and stirrer were stopped. A phase separation is happening within a couple of minutes.

[0134] The resulting mixture is then cooled to 80°C and kept for 16 h for further phase separation. The second phase (lower phase, diethylene glycol rich) is separated.

[0135] The composition of the first phase (upper phase, polyol substance rich) includes 65 wt.-% polyol, 23.5 wt.-% diethylene glycol, 8.7 wt.-% toluene diamine 0.26 wt.-% potassium and 0.45 wt.- % water.

[0136] The composition of the second phase includes 68.3 wt.-% diethylene glycol, 13.6 wt.-% toluene diamine and 1.4 wt.-% potassium.

[0137] Phase separation was successful and the release of 89% of the expected toluene diamine indicates very high conversion. Expected amount of toluene diamine was determined by elemental analysis of nitrogen in the end-of-life foam mixture, assuming toluene diamine to be the only nitrogen source. With the acrylonitrile of the SAN-particles the expected toluene diamine amount is overestimated. Consequently a release of 89% of the expected toluene diamine indicates very high conversion.

[0138] Example 4: (Comparative example))

[0139] A sorted mixture of end-of-life polyurethane flexible foams with a graft polyol content of ~3-5 wt.% (according to NIR-measurements; 51 .6 wt.% of reaction mixture) was dosed in diethylene glycol (43 wt.%) as alcoholising substance in the presence of KOH (solid; 1.5 wt.%) at 200°C over 15 minutes. 10 minutes after the last foam was added to the reaction mixture, water was added (3.8 wt.%) and everything was stirred, under N2 (or air), and at normal pressure (1013.25 mbar) with a reflux condenser at 170°C for 2 hours. Then water was removed by distillation for 1 h at normal pressure (1013.25 mbar) until the temperature of the reaction mixture has increased to 180°C, when the heating and stirrer were stopped.

[0140] The resulting mixture is then cooled to 80°C and kept at 80°C for 16 h. No phase separation was obtained due to high viscosity and high solid content. Filtration of the solids using a filter with 20 pm mesh size was not possible due to clogging of the filter.

[0141] Literature cited

[0142] CN 106700126 US20010027246

[0143] EP 1 142 945 A2

[0144] US 9,023,907 B2

[0145] WO 2015 / 121057

[0146] WO 2013 / 139781

[0147] "Kunststoffhandbuch [Plastics handbook], volume 7, Polyurethane [Polyurethanes]", Carl Hanser Verlag, 3rd edition 1993, chapter 3.1 , 3.2 and 3.3.2

[0148] WO 2006 / 034800

[0149] EP 0090444

[0150] WO 2005 / 090440

[0151] WO 2022 / 171586

[0152] US 2022 / 0251328

[0153] EP22178796.3

[0154] EP22178797.1

[0155] Ullmann’s Encyclopedia of Industrial Chemistry, 7thed. Vol. 20, 2012, p. 63-82

[0156] WO 99 / 54289 A

[0157] WO 2004 / 056756 A

[0158] Ullmann’s Encyclopedia of Industrial Chemistry, 4thed. Vol. 13, 2012, p. 353

[0159] DE 25 870847 A

[0160] EP 1532107 A

[0161] EP 0570799 A

[0162] EP 0289840 A

[0163] EP 2044009 A1

[0164] WO 2013 / 060836 A

[0165] WO 2013 / 079517 A

[0166] WO 2022 / 106716

[0167] EP 1761483 B1

[0168] EP 2079684 B1

[0169] EP 2188247 B1

[0170] EP 2408738 B1

[0171] EP 2539314 B1

[0172] WO2018 / 185168

[0173] EP 3 250 622 B1

Claims

Claims1 . A process for recycling of graft polyol containing polyurethane containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane material which comprises a graft polyol; b) depolymerization of the comminuted polyurethane provided in step a) by hydrolysis, hydroalcoholysis, hydroammonolysis or hydroaminolysis, wherein the content of water in the reaction mixture is in the range of from 3.5 to 15 wt.-% based on the reaction mixture, c) optionally adjusting the water content to achieve phase separation; d) separation of the amine component and the polyol components obtained in step b) or step c), to amine rich and an amine poor phase.

2. The process according to claim 1 , wherein depolymerization according to step b) is carried out by a process comprising a hydrolysis step together with applying an alcoholysis, ammonolysis, or aminolysis.

3. The process according to claim 1 or 2, wherein step c) is carried out and the water content is adjusted in a range of from 0.1 to 1 wt.-% based on the reaction mixture.

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 step a1 ) and / or step a2) a1 ) sorting of the materials using optical methods, in particular NIR spectroscopy; a2) at least partial extraction of flame retardants from the comminuted polyurethane material.

6. The process according to any one of claims 1 to 5, wherein the process further comprises step e) e) conversion of the amine component to obtain an isocyanate composition.

7. Polyol composition obtained or obtainable according to the process of any one of claims 1 to 6.

8. Use of the polyol composition according to claim 7 or a polyol composition obtained or ob- tainable according to the process of any one of claims 1 to 6 for the preparation of polyurethanes.

9. Isocyanate composition obtained or obtainable according to the process according to any one of claims 1 to 6.

10. Use of the isocyanate composition according to claim 9 or an isocyanate composition obtained or obtainable according to the process of any one of claims 1 to 6 for the preparation of polyurethanes.