Improved method for depolymerizing polyurethane

Abstract

本発明は、ポリウレタン(「PU」)、特にポリウレタン廃棄物からリサイクルポリオール(「PPU」)およびリサイクルアミン(「APU」)を製造するための改善された方法に関する。PUを加水分解し、典型的にはPUの加水分解から生じるポリオールPPUおよびアミンAPUの主要部分を含む有機相(「PO」)と、水相(「PW」)とを含む粗生成物(「RH」)を得る。次いで、POの少なくとも一部(「PO1」)をRHから分離する。残留水WおよびアミンAPUを蒸留によってPO1から分離して、水蒸気Vおよびアミン画分FAを得る。次いで、典型的にはポリオールPPUの主画分を含有する残りの有機相PO2の少なくとも一部PO3をストリッピングによってさらに精製し、水蒸気Vを向流ストリッピングガスとして使用する。好ましくは、PO1からの水の蒸留およびストリッピング工程は、同じ塔K1で行う。

Description

Technical Field

[0001] The present invention relates to a method for producing recycled polyol (「P PU 」) and recycled amine (「A PU 」) from polyurethane (「PU」), particularly polyurethane waste. The PU is hydrolyzed, and an organic phase (「P PU 」) containing mainly polyol P PU and amine A O 」) and an aqueous phase (「P W 」) are obtained in a crude product (「R H 」). Then, at least a part (「P O 」) of P O1 」) is separated from R H ). Residual water W and amine A PU are separated from P O1 by distillation to obtain water vapor V and an amine fraction F A ). Then, at least a part P PU of the remaining organic phase P O2 containing mainly the main fraction of polyol P O3 is further purified by stripping, using water vapor V as a countercurrent stripping gas. Preferably, the distillation and stripping steps for water from P O1 are carried out in the same column K1.

[0002] The method according to the present invention is highly energy-efficient and resource-efficient. In particular, by combining the distillation apparatus and the stripping apparatus to reduce the number of distillation apparatuses required, the cost of the entire apparatus is reduced.

[0003] Background of the Invention Polyurethane is an extremely useful material in the manufacture of rigid and flexible foams, solid and microcellular elastomers, sealants, coatings, and adhesives. Polyurethane's versatility, relatively low cost, and excellent properties have led to the rapid growth of the polyurethane industry over the past 50 years. Currently, thousands of tons of polyurethane are produced worldwide every year. Unfortunately, most polyurethane is, to varying degrees, a cross-linked thermosetting material. Therefore, unlike thermoplastic resins such as polyethylene, polypropylene, and polystyrene, scrap or waste polyurethane cannot be easily remelted or reprocessed into useful articles. For economic and environmental reasons, it is highly desirable to reuse or recover the large quantities of scrap or waste polyurethane generated each year rather than incinerate or landfill it. Therefore, considerable effort has been invested in devising methods to recover useful chemical components from scrap polyurethane material.

[0004] International Publication No. 2023 / 083968 discloses a method for cleaving PU using a catalyst along with a reagent comprising a primary or secondary organic amine and / or amino alcohol and water. The resulting product can be recovered by distillation and / or stripping.

[0005] International Publication No. 2023 / 072985 outlines the most important PU recycling processes, namely hydrolysis, glycol decomposition, and mixed forms ("hydroglycolysis"). It also highlights the challenges of large-scale PU recycling, particularly regarding the resource efficiency and technical requirements of PU recycling facilities. In particular, there is a need in the art for methods that enable the efficient separation, purification, and recycling of typical cleavage products obtained during PU depolymerization, i.e., amines and polyols, which are the basic building blocks of all PU polymers.

[0006] Therefore, the fundamental problem of the present invention was to provide a method for recycling PU, i.e., a method for producing recycled polyols and recycled amines from PU, that is simple in procedure, resource-efficient, and enables simplified equipment engineering.

[0007] Brief description of the invention Remarkably, the present invention has found a method for producing recycled polyols and recycled amines from PU, which solves the above problems.

[0008] The method according to the present invention involves at least one recycled polyol P from at least one polyurethane PU. PU and at least one recycled amine A PU A method for manufacturing a product, wherein at least one type of polyurethane PU is provided, preferably as PU foam, more preferably as soft PU foam.

[0009] The method according to the present invention is a. By contacting PU with water W and at least one base B, PU is at least partially hydrolyzed to form polyol P PU , amine A PU Crude product R comprising water W, at least one base B, and optionally solid S H A process to obtain crude product R H Organic phase P O and aqueous phase P W Processes including b. Crude product R H From organic phase P O at least part of P O1 A process for separating P O1 Polyol P PU , amine A PU , including water W, process, cP O1 from at least a portion of water W and amine A PU At least a portion of it is separated by distillation, - Water vapor V, - Amine A PUFraction F containing A , - Polyol P PU , optionally amine A PU and optionally an organic phase P containing water W. O2 The process of obtaining d.Organic phase P O2 at least part of P O3 The process of purification by stripping. In a method including, In step d, water vapor V is used as the stripping gas, P O3 It is characterized by being used in a countercurrent.

[0010] Therefore, the method according to the present invention makes it possible to efficiently use the steam obtained during the distillation of the organic phase, thus saving resources and simplifying the entire process. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows a preferred embodiment of the method according to the present invention.

[0012] Hydrolysis crude product R H Organic phase P O1 <1> This is the distillation column K1 <4> Evaporator connected <2> It is supplied to the crude product R. H This is obtained after hydrolysis of PU using base B and optionally a quaternary ammonium salt Q as a phase transfer catalyst. Organic phase P O1 <1> is polyol P PU , amine A PU The evaporator contains residual water W, and at least one of the amine decomposition products of a quaternary ammonium salt Q and Q. <2> So, water and optionally P O1 <1> Other components contained in it, for example, amine A PU P O1<1> It evaporates from there. This creates a water vapor V flow. <3> You can obtain Tower K1 <4> Guided by this, other impurities that are drawn in along with it are removed. Next, the residue of this distillation process <5> It is then led to a further purification step, typically carried out in a short-pass evaporator, thin-film evaporator, or further distillation column K2. In this additional purification step, polyol P PU and amine A PU These are preferably further separated from each other by distillation. The polyol fraction obtained by this further purification is then... <6> Tower K1 <4> Guided by, arbitrarily, heat exchanger <10> It may be heated via [a specific method].

[0013] Tower K1 <4> Inside, water vapor V <3> is a filler <41> Passing through. Tower K1 <4> is a filler <41> Above, water vapor V <3> Impurities are drawn in along with it, such as the amine decomposition products of Q and / or amine A PU Any condenser used to condense and remove other hydrolysis products such as fractional condensation <42> These compounds may also be present as condensates in the piping. <7> It is removed via [method]. Optionally, polyol P PU If additional steam is needed to strip it, add liquid water via the pipes. <8> via Tower K1 <4> Such additional water can be supplied to the heat exchanger. <9> It can be heated via piping. Optionally, <7> The condensates removed via Column K1 are partially or completely removed. <4> It may also be used as a return flow to the piping, in which case <8> via Tower K1 <4> Additional water supplied to the piping <14> It may be mixed via a method.

[0014] Water vapor V <3> Tower K1 <4> Ascend to the top of Tower K1 <4> Inside or Tower K1 <4> Heat exchanger built into the outside <43> It may be further heated by steam V. <3> is the second filler <44> Passing from below, Tower K1 <4> Polyol fraction supplied from above <6> It comes into contact with such water vapor V <3> and polyol fraction <6> Due to the countercurrent, the polyol fraction <6> This is the polyol fraction that has been stripped of impurities and purified. <11> liquid collector <45> It is obtained there, and then Tower K1 <4> It is extracted from. The water vapor obtained after stripping contains the amine decomposition products of Q and / or amine A PU It contains other hydrolysis products such as those listed above. This is Tower K1 <4> It is taken out from the top and the condenser <12> It is then condensed. Next, the resulting condensed flow <13> The water may be further processed, for example, in a further distillation, and then recycled, and then piped <8> via Tower K1 <4> Recirculate to strip again and / or the desired amine A PU It may be used for the isolation of the product. Alternatively, water can be recycled back into the reaction process to obtain more crude hydrolysis product R H And along with that, more organic phase P O1 <1> It is possible to generate and

[0015] Detailed description of the invention The method according to the present invention involves at least one recycled polyol P from at least one polyurethane PU. PU and at least one recycled amine A PU This is obtained. In the context of the present invention, "Recycled" refers to the decomposition product P obtained by the method according to the present invention, i.e., by a method including a hydrolysis step of PU. PU and A PU This means that it can be reused, for example, in the synthesis of further PU, particularly PU foam, preferably soft PU foam.

[0016] Polyol P that can be used in the method according to the present invention PU , amine A PUAnd at least one type of polyurethane (PU) will be described further below.

[0017] 1. Polyol P PU "Polyol P PU " encompasses any organic compound having two or more isocyanate-reactive groups, preferably two or more OH groups. Such polyols are described, for example, in Japanese Patent Publication No. 4-136017, International Publication No. 2022 / 042909, International Publication No. 2022 / 042910, International Publication No. 2023 / 072985, and International Publication No. 2023 / 078802.

[0018] Polyol P recovered by the method of the present invention PU The structure of the polyol correlates with the structure of the polyol used in the production of polyurethane PU processed by the method of the present invention.

[0019] Preferably, at least one polyol P PU teeth, - Polyether polyol; - Polyester polyol; - Hydroxyl-containing aliphatic polycarbonates, especially polyether polycarbonate polyols; - Natural oil-based polyols (NOPs); - Polymer polyol (filled polyol); - Prepolymer polyol; - Autocatalytic polyol It is selected from the group consisting of the following.

[0020] More preferably, at least one polyol P PU The polyol P is selected from the group consisting of polyether polyols and polyester polyols, and more preferably at least one polyol P PU It is selected from polyether polyols.

[0021] At least one type of polyol P PUPreferably, the average sensory value is 2 to 6, more preferably 2 to 3, and most preferably 2.

[0022] "Functional value" refers to the number of isocyanate-reactive groups, preferably OH groups, per molecule.

[0023] Two or more types of polyols P PU Mixture M P So, the "average sensory value" is the mixture M P The number of all isocyanate reactive groups, preferably all OH groups, in the mixture M P All polyols P inside PU This refers to the value obtained by dividing by the amount of substance (moles).

[0024] At least one type of polyol P PU It preferably has an average number molecular weight in the range of 500 to 15000 g / mol. The number average molecular weight is usually determined by gel permeation chromatography ("GPC"), particularly using polypropylene glycol as a reference and tetrahydrofuran ("THF") as the eluent.

[0025] At least one type of polyol P PU It preferably has an OH value in the range of 10 to 1200 mg KOH / g. The OH value is determined in particular in accordance with DIN standard DIN 53240:1971 12.

[0026] 1.1 Polyether polyol At least one type of polyol P PU A preferred option is a polyether polyol, which is known to those skilled in the art and is preferably a polyether having primary and / or secondary terminal groups, preferably hydroxyl groups. Amine-functionalized polyethers (e.g., "Jeffamine" polyoxypropylamine, marketed by Texaco Chemical Co.) can also be used. It is preferable to use a polyether polyol having hydroxyl terminal groups.

[0027] At least one type of polyol P PU Polyether polyols, which are a preferred option, can be obtained by known methods. Such materials are generally produced by catalytic ring-opening polymerization of one or more cyclic ethers such as epoxides, oxetanes, or oxolanes. The functional value (number of active hydrogens) of the polyether can be altered using initiators having two or more active hydrogens, such as polyhydric alcohols, amines, or acids. When two or more cyclic ethers are used, they can be reacted simultaneously (to obtain random copolymers) or sequentially (to obtain block copolymers). Exemplary cyclic ethers include propylene oxide, ethylene oxide, butylene oxide, tetrahydrofuran, and oxetane. Examples of polyether polyols include polypropylene glycol, polyethylene glycol, polytetramethylene glycol, polytrimethylene glycol, polypropylene glycol capped with ethylene oxide, and random copolymers of ethylene oxide and propylene oxide.

[0028] At least one type of polyol P PU Polyether polyols, which are preferred options, can also be obtained by the anionic polymerization of alkylene oxides ("AO") in the presence of alkali metal hydroxides, alkali metal alkoxides or amines as catalysts, and by the addition of at least one starter molecule ("SM") preferably containing two or three reactive hydrogen atoms, or by the cationic polymerization of AO in the presence of a Lewis acid such as antimony pentachloride or boron trifluoride etherate, or by the catalytic action of complex metal cyanides.

[0029] Preferred alkylene oxides (AOs) contain 2 to 4 carbon atoms. Examples include tetrahydrofuran, 1,3-propylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, and 2,3-butylene oxide. Ethylene oxide and 1,2-propylene oxide are preferably used. Alkylene oxides can be used individually, cumulatively, in blocks, alternately, or as mixtures.

[0030] The starter molecule SM used may be a compound having at least two, preferably two to eight, hydroxyl groups or at least two primary amino groups in the molecule.

[0031] The preferred starter molecule SM is, - water; - Divalent, trivalent, or tetravalent alcohols selected particularly from ethylene glycol, propane-1,2-diol, propane-1,3-diol, diethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, and pentaerythritol; - Castor oil, which is a fatty acid triglyceride in which at least two fatty acids have at least one -OH group, preferably a triglyceride in which at least two of three fatty acid residues, preferably each, is 12-hydroxy-9-octadecenoic acid (known as "ricinoleic acid"); - Higher polyfunctional polyols, especially sugar compounds, such as glucose, sorbitol, mannitol, and sucrose; - Polyhydric phenols, resols, such as oligomeric condensation products of phenol and formaldehyde, as well as Mannich condensates of phenol, formaldehyde and dialkanolamines and melamine, or amines, such as aniline, ethylenediamine ("EDA"), toluenediamine ("TDA"), diphenylmethanediamine ("MDA", which is preferably diphenylmethane 2,4'-diamine or diphenylmethane 2,2'-diamine), and 1,5-pentamethylenediamine ("PMDA"). It is selected from the group consisting of the following.

[0032] The selection of a suitable starter molecule SM depends on the specific application of the polyether polyol obtained in polyurethane production (for example, polyols used in the production of flexible PU foam are different from those used in the production of rigid PU foam).

[0033] Polyol P PU Polyether polyols, a preferred option, can also be obtained from natural sources. The preparation of such polyether polyols and those from biological sources is described in H. Sardon, D. Mecerreyes, A. Basterretxea, L. Averous, C. Jehanno, ACS Sustainable Chem. Eng. 2021, 9, 10664-10677 (hereinafter, "Sardon et al.").

[0034] 1.2 Polyester Polyol Polyol P PU Another group of polyols that is a preferred option is polyester polyols, which are preferably based on esters of polybasic aliphatic or aromatic carboxylic acids having 2 to 12 carbon atoms.

[0035] Examples of aliphatic carboxylic acids include succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, and fumaric acid. Examples of aromatic carboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, and the isomer naphthalenedicarboxylic acid. Polyester polyols are obtained by condensation of these polybasic carboxylic acids with polyhydric alcohols, preferably diols or triols having 2 to 12, more preferably 2 to 6 carbon atoms, preferably trimethylolpropane and glycerol.

[0036] Polyol P PUPolyester polyols, a preferred option, can also be obtained from natural sources. The preparation of such polyester polyols and those from biological sources is described by Sardon et al.

[0037] 1.3 Hydroxyl-containing aliphatic polycarbonate Polyol P PUAnother group of polyols that are a preferred option, hydroxyl-containing aliphatic polycarbonates, are polyols containing carbon dioxide bonded in the form of carbonate[-OC(=O)-O]. Since carbon dioxide is formed in large quantities as a byproduct in many processes of the chemical industry, the use of carbon dioxide as a comonomer in alkylene oxide polymerization is of particular interest from a commercial standpoint. Partially replacing alkylene oxides in polyols with carbon dioxide could significantly reduce the production cost of polyols. Furthermore, the use of CO2 as a comonomer is highly environmentally advantageous, as this reaction corresponds to the conversion of greenhouse gases into polymers. Such polyols are described, for example, in J. Xu, E. Feng, J. Song, J Appl Polym Sci. 2014, 131: 10.1002 / app.39822. The preparation of these polyols by the addition of alkylene oxides and carbon dioxide to H-functional starter materials using catalysts is known. Various catalyst systems can be used here: the first generation consisted of heterogeneous zinc or aluminum salts, as described, for example, in U.S. Patent No. 3,900,424 or U.S. Patent No. 3,953,383. In addition, mononuclear and dinuclear metal complexes have been successfully used in the copolymerization of CO2 with alkylene oxides (International Publication Nos. 2010 / 028362, 2009 / 130470, 2013 / 022932, or 2011 / 163133). The most important class of catalyst systems for the copolymerization of carbon dioxide with alkylene oxides is the class of complex metal cyanide catalysts, also known as "DMC catalysts" (U.S. Patent No. 4,500,704, International Publication No. 2008 / 058913). Suitable alkylene oxides and H-functional starter materials are also used in the production of carbonate-free polyether polyols, as described above.

[0038] 1.4 Natural Oil-Based Polyols (NOPs) Polyol P PUA further group of polyols that are preferred options are polyols based on renewable raw materials, namely natural oil-based polyols (NOPs). The use of NOPs for the manufacture of PU foams is gaining interest in light of the long-term limitations on the availability of fossil resources, namely petroleum, coal, and gas, and in light of rising crude oil prices. NOPs have already been described numerous times in such applications (International Publication 2005 / 033167, U.S. Patent Application Publication 2006 / 0293400, International Publication 2006 / 094227, International Publication 2004 / 096882, U.S. Patent Application Publication 2002 / 0103091, International Publication 2006 / 116456, and International Publication 2005 / 033167). NOPs are currently commercially available from various manufacturers (U.S. Patent Publication No. 2006 / 0167125, U.S. Patent Publication No. 2006 / 0229375, International Publication No. 2009 / 058367). Depending on the base material, e.g., soybean oil, coconut oil, or castor oil (as shown in Figure 2B of Sardon et al.) and subsequent post-treatment, polyols with different properties can be obtained. Here, it is possible to distinguish essentially two groups: a) polyols based on renewable raw materials modified to be usable up to 100% in the manufacture of polyurethanes (U.S. Patent Publication No. 2006 / 0167125, U.S. Patent Publication No. 2006 / 0229375); b) polyols based on renewable raw materials that, due to their processability and properties, can replace petrochemical polyols in certain proportions only (International Publication No. 2009 / 058367). As described above, polyol P PU The polyether polyols, polyester polyols, and other polyols that can be selected can also be obtained from natural sources (see Sardon et al.).

[0039] 1.5 Polymer polyols (filler polyols) Polyol P PUA further class of polyols that are a preferred option is the so-called polymer polyol (filled polyol). A key feature of these polyols is that they contain solid organic fillers dispersed up to 40% or more solids. Various types of polymer polyols are available, such as SAN, PUD, and PIPA polyols. SAN polyol is styrene-acrylonitrile ( s tyrene- a crylo n It is a highly reactive polyol containing a dispersion copolymer based on itrile) ("SAN"). PUD ("Polyurea dispersion ( p oly- u rea- d PIPA (polyisocyanate polyaddition) is a highly reactive polyol that contains polyurea in a dispersed form. p oly i socyanate p oly a Polyols are highly reactive polyols containing dispersed polyurethane, formed, for example, by an in situ reaction between isocyanates and alkanolamines in conventional polyols.

[0040] Depending on the application, the preferred solids content is typically 5% to 40% by weight based on the polyol. The solids content of polymer polyols contributes to improved porosity, which results in a more controlled foaming process, especially when using TDI ("toluene diisocyanate"), and prevents foam shrinkage. For this reason, the solids content acts as an essential processing aid. A further function is to control foam hardness by the solids content in the foam formulation, as higher solids content results in higher foam hardness. Formulations containing polymer polyols tend to require additional physical stabilization in addition to chemical stabilization by crosslinking reactions, as they have significantly lower self-stabilization. Depending on the solids content, polyols can be used alone or in combination with the unfilled polyols described above.

[0041] 1.6 Prepolymer Polyols Polyol P PU A further class of polyols, which are preferred options of , are obtained as prepolymers by reacting a polyol with an isocyanate in a molar ratio of 100:1 to 5:1, preferably 50:1 to 10:1. Such prepolymers are preferably constituted in the form of a polymer solution, and the polyol preferably corresponds to the polyol used for preparing the prepolymer.

[0042] 1.7 Self-catalytic polyols Polyol P[[ID=IO]] PU A further class of polyols, which are preferred options of , are so-called self-catalytic polyols, especially self-catalytic polyether polyols. This type of polyol is based on, for example, polyether blocks, preferably ethylene oxide and / or propylene oxide blocks, and further contains catalytically active functional groups, such as nitrogen-containing functional groups, especially amino groups, preferably tertiary amine functional groups, urea groups, and / or heterocycles containing nitrogen atoms. By using such self-catalytic polyols in the production of PU foams, preferably flexible PU foams, it is possible to reduce the amount of catalyst that needs to be additionally used according to the application and / or to adapt to specific desired foam properties. Suitable polyols are described, for example, in WO 0158976, WO 2005 / 063841, WO 02 / 22702, WO 2006 / 055396, WO 03 / 029320, WO 01 / 58976, US 6,924,321, US 6,762,274, WO 2008 / 079614, WO 2004 / 060956 or WO 2013 / 102053, and can be purchased, for example, under the trade names Voractiv™ and / or SpecFlex™ Activ from Dow.

[0043] Depending on the required properties of the resulting form, advantageously, suitable polyols such as those described in, for example, US Patent Application Publication No. 2007 / 0072951, International Publication No. 2007 / 111828, US Patent Application Publication No. 2007 / 0238800, US Patent No. 6,359,022 or International Publication No. 96 / 12759 can be used. Further polyols are known to those skilled in the art and can be found, for example, in European Patent No. 0380993 or US Patent No. 3,346,557, the entire contents of which are incorporated by reference.

[0044] 1.8 Preferred polyols 1.8.1) More preferably, at least one polyol P PU has the general structure of formula (I): HX 2 -V 1 -X 1 H, wherein the residue V 1 is a divalent hydrocarbon residue optionally containing at least one group selected from an ester group, an ether group, a thioether group, an amine group, a cyano group, a hydroxy group.

[0045] V 1 is preferably selected from the group consisting of alkylene, alkenylene, alkynylene, aromatic hydrocarbon residues, and optionally the alkylene, alkenylene, alkynylene and / or aromatic hydrocarbon residues contain at least one group selected from an ester group, an ether group, a thioether group, an amine group, a cyano group, a hydroxy group.

[0046] X 1 and X 2 are each independently selected from the group consisting of -O-, -NH-, -N(R')-, -S-, wherein R' is an alkyl group, preferably an alkyl group having 1 to 6 carbon atoms.

[0047] Preferably, X 1 = -O- and X 2 = -O-.

[0048] 1.8.2) The polyol P of formula (I)PU Preferably, the formulas are (IA), (IB), (IC), and more preferably (IA): [ka] Having a general structure selected from the group consisting of, In the formula, q2, q3, q4, q5, q6, q7, and q8 are each an integer of 2 or more, preferably in the range of 2 to 1000, more preferably in the range of 5 to 500, and even more preferably in the range of 10 to 200. V 2 , V 3 , V 4 , V 5 , V 6 , V 7 , V 8 Each of these is independent of equation -C n H 2n A base having -, where n is an integer, n=1 to 100, preferably n=2 to 50, more preferably n=2 to 10, even more preferably n=2 to 6, even more preferably n=2 to 4, even more preferably n=2 to 3, Preferably V 2 , V 3 , V 4 , V 5 , V 6 , V 7 , V 8 Each of these is independently selected from the group consisting of -CH2CH2-, -CH2-CH(CH3)-, -CH(CH3)-CH2-, and -CH2CH2CH2-. Polyol P following general structure (IA) PU Residue V 2 They are the same or different. Polyol P following the general structure (IB) PU Residue V 3 They are the same or different. Polyol P following the general structure (IB) PU Residue V 4 They are the same or different. Polyol P following the general structure (IB) PU Residue V 5They are the same or different. Polyol P following general structure (IC) PU Residue V 6 They are the same or different. Polyol P following general structure (IC) PU Residue V 7 They are the same or different. Polyol P following general structure (IC) PU Residue V 8 They are either the same or different.

[0049] According to the present invention, "-C n H 2n The "-" preferably includes linear and branched alkylene residues selected from the group consisting of methylene, ethylene, n-propylene, and isopropylene, and more preferably selected from the group consisting of ethylene, n-propylene, and isopropylene.

[0050] Polyol P of formulas (IA), (IB), (IC) PU It is a polyether polyol.

[0051] 2. Amine A PU Amine A PU The structure of the polyisocyanate contained in the polyurethane PU used in the method of the present invention correlates with the structure of the polyisocyanate contained in the polyurethane PU used in the present invention. The "amine A" used in the present invention PU This includes an amine having two or more amine groups, preferably an amine having two or more primary amino groups in the molecule.

[0052] In a preferred embodiment, at least one amine A PU Equation (II): H2N-W 1 -Has a general structure due to NH2, in which the residue W 1 This is a divalent hydrocarbon residue that optionally contains at least one group selected from an ester group, an ether group, a thioether group, an amine group, a cyano group, a hydroxyl group, and an amino group.

[0053] W1 Preferably selected from the group consisting of alkylene, alkenylene, alkylylene, and aromatic hydrocarbon residues, wherein the alkylene, alkenylene, alkylylene, and / or aromatic hydrocarbon residues optionally contain at least one group selected from ester groups, ether groups, amine groups, thioether groups, hydroxyl groups, cyano groups, and amino groups.

[0054] W 1 The residue is more preferably selected from the group consisting of alkylenes and aromatic hydrocarbon residues, and optionally the alkylene and / or aromatic hydrocarbon residue contains at least one group selected from a hydroxyl group and an amino group.

[0055] 2.1) More preferably, W in formula (II) 1 This is selected from the group consisting of C1-C6 alkylenes and formulas (II-A), (II-B), (II-C), (II-D), (II-E), and more preferably from the group consisting of C5-alkylene, C6-alkylene, and formulas (II-A), (II-B), (II-C), (II-D), (II-E), [ka] In equations (II-A), (II-B), (II-C), (II-D), and (II-E), the "( * The bond indicated by ) refers to a bond to one of the amino groups in formula (II), and the "( ** The bond indicated by ) refers to a bond to another amino group in formula (II).

[0056] In equation (II-A), "( * )" and "( ** The two bonds indicated by ) are preferably located in the para position of the aromatic ring relative to each other.

[0057] In equation (II-B), "( * )" and "( **The two bonds indicated by ) are preferably located at the 2,4 or 2,6 positions of the aromatic ring relative to the methyl group.

[0058] In equation (II-C), "( * )"or"( ** The aromatic carbon atom that is not bonded to one of the bonds shown in ")", i.e., the aromatic carbon atom having hydrogen in formula (II-C), may be substituted with a group selected from an amino group and an alkyl group, the alkyl group being preferably methyl. More preferably, "( * )"or"( ** All aromatic carbon atoms in formula (II-C) that are not bonded to one of the bonds indicated by ) each have a hydrogen atom.

[0059] In equation (II-D), "( * )" and "( ** The two residues having the bond indicated by ) are preferably located in the para position of the aromatic ring relative to each other.

[0060] 2.2) In a more preferred embodiment, at least one amine A PU This is selected from the group consisting of phenylenediamine, toluenediamine ("TDA"), diamines and polyamines of diphenylmethane ("MDA"), 1,5-pentanediamine ("PDA"), 1,6-hexamethylenediamine ("HDA"), isophoronediamine ("IPDA"), and xylylenediamine ("XDA"). At least one amine A PU It is most preferable that it be TDA.

[0061] In TDA, the two amino groups are preferably located at the 2,4 or 2,6 positions of the aromatic ring relative to the methyl group.

[0062] 3. Polyurethane PU In step a of the method according to the present invention, polyurethane (PU) is used. This PU is then subjected to partial or complete hydrolysis in step a.

[0063] One of the advantages of the method according to the present invention is that it is applicable to a wide range of PUs. Therefore, the PU used in step a of the method of the present invention is not particularly limited, and any known polyurethane PU can be used in the method of the present invention. Preferably, the polyurethane PU used in step a is polyurethane waste.

[0064] The PU used in step a of the present invention is preferably provided as PU foam, more preferably as soft PU foam.

[0065] In particular, the polyurethane PU that can be used in the method of the present invention is made from an active hydrogen-containing polyol, preferably a polyether and a polyisocyanate. This type of polyurethane is known and is described, for example, in U.S. Patent No. 5,208,379, Ulrich, “Urethane Polymers”, in Encyclopedia of Chemical Technology, Vol. 23, pp. 576-608 (1983), and Backus et al., “Polyurethanes”, in Encyclopedia of Polymer Science and Technology, Vol. 13, pp. 243-303 (1988).

[0066] Typically, the polyurethane used in step a of the method according to the present invention is polyol P PU At least two OH groups of each are connected to amine A via a urethane functional group. PU Attached to the NH group of amine A PU At least two NH groups are connected to the polyol P via urethane functional groups. PU It is a polymer bonded to the OH group.

[0067] The PU used in the method of the present invention can be derived from any polyisocyanate reactant (i.e., an organic compound containing two or more isocyanate groups). Suitable polyisocyanates include aliphatic diisocyanates, cycloaliphatic diisocyanates, arylalkyl diisocyanates, aromatic diisocyanates (e.g., toluene diisocyanate and diisocyanatodiphenylmethane), aromatic triisocyanates, and isocyanate mixtures such as those generally referred to as polymeric diphenylmethane diisocyanate ("PMDI"), but are not limited thereto. Modified, masked or blocked polyisocyanates can of course also be utilized. The PU subjected to the method according to the present invention may contain a group selected from allophanate groups, isocyanurate groups, urea groups. If one or more of these groups are present, at least a part of these groups can be cleaved during step a. The PU subjected to the method of the present invention can contain conventional additional reactants or additives known in the art, such as chain extenders or curing agents (relatively low molecular weight active hydrogen-containing compounds such as glycols and diamines or polyamines), physical or chemical blowing agents, flame retardants, surfactants, fillers, stabilizers, antioxidants, colorants, polymers other than PU polymers (e.g., styrene-acrylonitrile copolymers as found in polymer polyols), catalysts, such as catalysts that promote the gelation reaction (isocyanate-polyol), the foaming reaction (isocyanate-water), and / or the dimerization or trimerization of isocyanates. The polyurethane may be in the form of a solid, microcellular or foam, and can vary from rubbery, elastomeric, flexible materials to rigid substances.

[0068] In particular, at least one PU subjected to step a. of the present invention contains at least one polymer chain PU S and the PU S has m mutually bonded repeating units of chemical structure (III)

Chemical formula

[0069] In particular, the PU used in step a. of the method of the present invention is, from a formal standpoint, P PU The hydroxyl group and A PU Polyol P is mutually bonded via urethane bonds that connect the amino groups of the polyols. PU and amine A PU This includes the hydrolysis of PU in step a, which causes the urethane groups to cleave, PU and A PU It is released.

[0070] Therefore, in a preferred embodiment of the present invention (hereinafter abbreviated as "preferred embodiment Θ"), polyol P PUIt has a general structure selected from the group consisting of formulas (IA), (IB), and (IC) as defined in Section 1.8.2), more preferably formula (IA) as defined in Section 1.8.2), At least one type of amine A PU Equation (II): H2N-W 1 -Has a general structure due to NH2, in which the residue W 1 This is as defined in Section 2.1), and more preferably, at least one amine A PU This is as defined in section 2.2), The at least one PU used in step a of the present invention is at least one polymer chain PU S Includes PU S is the chemical structure (III) [ka] It has m mutually linked repeating units, m is 4 or more, preferably 4 to 10 6 , even more comfortable 10~10 5 , even more comfortable 100~10 4 It is an integer, PU S The repeating units of the chemical structure (III) within are either identical to each other or at least partially different. PU S The repeating units of the chemical structure (III) are linked to one another such that the bonds indicated by "($)" in a particular repeating unit are linked by the bonds indicated by "($$)" in adjacent repeating units. R 1 It is selected from one of the divalent residues according to formulas (III-A), (III-B1), (III-B2), (III-C1), and (III-C2). [ka] In the formula, V 2 , V 3 , V 4 , V 5 , V 6 , V 7 , V 8As defined in Section 1.8.2 for equations (IA), (IB), and (IC), q2 in equation (III-A) * The following relationship applies to q2 defined in equation (IA): q2 = 1 + q2 * Depends on, q3 in equations (III-B1) and (III-B2) * The following relationship applies to q3 defined in equation (IB): q3 = 1 + q3 * Depends on, q4 in equation (III-B1) * The following relationship applies to q4 defined in equation (IB): q4 = 1 + q4 * Depends on, In equation (III-B1), q5 is defined as in equation (IB), In equation (III-B2), q4 is defined as in equation (IB), q5 in equation (III-B2) * The relationship between q5, defined for equation (IB), and the following equation is given: q5 = 1 + q5 * Depends on, q6 in equations (III-C1) and (III-C2) * The relationship between q6, defined for equation (IC), and the following equation is given: q6 = 1 + q6 * Depends on, q7 in equation (III-C1) * The following relationship applies to q7 defined in equation (IC): q7 = 1 + q7 * Depends on, In equation (III-C1), q8 is defined as in equation (IC), In equation (III-C2), q7 is defined as in equation (IC), q8 in equation (III-C2) * The following relationship applies to q8 defined in equation (IC): q8 = 1 + q8 * Depends on, The bonds indicated by "(#)" in equations (III-A), (III-B1), (III-B2), (III-C1), and (III-C2) correspond to the bonds indicated by "($)" in equation (III), and the bonds indicated by "(##)" in equations (III-A), (III-B1), (III-B2), (III-C1), and (III-C2) correspond to the R in equation (III). 1 The bond from to the oxygen atom, i.e., the bond represented by "($)" in formula (III), is different from R. 1 In response to joining from, R 2 It is selected from the group consisting of C1-C6 alkylenes and formulas (II-A), (II-B), (II-C), (II-D), (II-E), and more preferably selected from the group consisting of C5-alkylene, C6-alkylene, and formulas (II-A), (II-B), (II-C), (II-D), (II-E) as defined in Section 2.1 above, and in relation to formula (III), the "( * The bond indicated by ")" refers to the bond to one nitrogen of the urethane functional group in formula (III), and the "( ** The bond indicated by ) refers to the bond of the other urethane functional group to nitrogen in formula (III).

[0071] PU used in step a of the method according to the present invention, particularly polymer chain PU in embodiment Θ S This is the residue R defined above. 1 and R 2 It may include further iteration units different from the above. For example, PU S teeth, - Polyether polyols, especially those defined in Section 1.1 above; - Polyester polyols, especially those defined in Section 1.2 above; - Hydroxyl-containing aliphatic polycarbonates, especially polyether polycarbonate polyols, particularly those defined in Section 1.3 above; - Natural oil-based polyols (NOPs), especially those defined in Section 1.4 above; - A polymer polyol (filled polyol), especially those defined in item 1.5 above; - A prepolymer polyol, especially those defined in item 1.6 above; - A self-catalytic polyol, especially those defined in item 1.7 above It may contain further repeating units derived from at least one unit selected from the group consisting of.

[0072] 4. Step a. In step a. of the method according to the invention, the PU is at least partially hydrolyzed by contacting the PU with water and at least one base B.

[0073] Such hydrolysis reactions of PUs are known to those skilled in the art and are described, for example, in WO 2023 / 083968 and WO 2023 / 072985. These documents compare hydrolysis with other reactions for cleaving PUs such as glycolysis.

[0074] US Patent No. 5,208,379 also discloses typical hydrolysis conditions.

[0075] "Hydrolysis" in the context of the present invention means cleaving at least a part of the urethane groups in the PU by water molecules (as nucleophiles) to obtain the respective amines and polyols.

[0076] 4.1 Base B At least one base B used in step a. can be selected by those skilled in the art according to their own knowledge.

[0077] Preferably, at least one base B is selected from the group consisting of alkali metal phosphates, alkaline earth metal phosphates, alkali metal hydrogen phosphates, alkaline earth metal hydrogen phosphates, alkali metal carbonates, alkaline earth metal carbonates, alkali metal silicates, alkaline earth metal silicates, alkali metal bicarbonates, alkaline earth metal bicarbonates, alkali metal carboxylates, alkali metal acetates, alkaline earth metal carboxylates, alkaline earth metal acetates, alkali metal sulfites, alkaline earth metal sulfites, ammonium hydroxide, alkali metal hydroxides, alkali metal oxides, alkaline earth metal hydroxides, and alkaline earth metal oxides.

[0078] More preferably, at least one base B is selected from the group consisting of alkali metal phosphates, alkali metal hydrogen phosphates, alkali metal carbonates, alkali metal silicates, alkali metal bicarbonates, alkali metal carboxylates (carboxylates are particularly acetates), alkali metal sulfites, ammonium hydroxides, alkali metal hydroxides, alkali metal oxides, alkaline earth metal hydroxides, and alkaline earth metal oxides.

[0079] The alkali metal contained in base B is preferably selected from the group consisting of potassium, sodium, and lithium, and more preferably selected from the group consisting of potassium and sodium.

[0080] The alkaline earth metal contained in base B is preferably selected from the group consisting of beryllium, magnesium, calcium, strontium, and barium, and more preferably selected from the group consisting of magnesium and calcium.

[0081] More preferably, at least one base B is selected from the group consisting of potassium carbonate and sodium carbonate.

[0082] In a preferred embodiment, the ratio of the total weight of all base B used in step a. to the total weight of all PU subjected to step a. is in the range of 50:1 to 1:1, preferably 10:1 to 2:1, and most preferably 4:1.

[0083] 4.2 Phase transfer catalyst In a further preferred embodiment, the hydrolysis in step a. is catalyzed with at least one phase transfer catalyst selected from the group consisting of quaternary ammonium salts Q and organic sulfonates, preferably at least one phase transfer catalyst selected from the group consisting of quaternary ammonium salts Q.

[0084] The quaternary ammonium salt Q preferably has a general structure R 1 R 2 R 3 R 4 It has NX, and in the formula, R 1 , R 2 , R 3 and R 4 X is either the same or different, each being a hydrocarbyl group selected from alkyl, aryl, and arylalkyl groups, where X is selected from the group consisting of hydroxides, carbonates, bicarbonates, bisulfates, and carboxylates, where the carboxylate is preferably an acetate or halide, where the halide is preferably selected from chlorides and bromides or alkyl sulfates, and where the alkyl sulfate is preferably selected from methyl sulfate or ethyl sulfate. Preferably, X = hydroxide or bisulfate. Most preferably, X = hydroxide.

[0085] The quaternary ammonium salt Q preferably contains an ammonium cation having 6 to 30 carbon atoms.

[0086] The organic sulfonate preferably contains at least seven carbon atoms.

[0087] In a preferred embodiment, the hydrolysis in step a. is catalyzed with at least one quaternary ammonium salt Q, and more preferably, at least one quaternary ammonium salt Q comprises a cation selected from the group consisting of tetrabutylammonium cation and benzyltrimethylammonium cation. Even more preferably, at least one quaternary ammonium salt Q is selected from the group consisting of tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, and tetrabutylammonium bisulfate.

[0088] If at least one quaternary ammonium salt Q is used in step a., it is even more preferable that the total weight of all quaternary ammonium salt Q used in step a. is at least 0.5% by weight, more preferably in the range of 0.5 to 15% by weight, even more preferably in the range of 0.75 to 10% by weight, particularly preferably in the range of 0.90 to 8% by weight, and especially preferably in the range of 1.0 to 7% by weight, relative to the total weight of PU subjected to step a.

[0089] In an alternative embodiment of the method according to the present invention, at least the partial hydrolysis in step a is carried out without the addition of a phase transfer catalyst.

[0090] 4.3 Base-Catalyst Combinations In a preferred embodiment of the method of the present invention, at least one base B is used in step a. in a "base-catalyst combination" with at least one quaternary ammonium salt Q or an organic sulfonate. More preferably, at least one base B is used in step a. in a "base-catalyst combination" with at least one quaternary ammonium salt Q.

[0091] More preferably, the base-catalyst combination is selected from the group consisting of BCC1, BCC2, and BCC3, and in particular from the group consisting of BCC1 and BCC2.

[0092] BCC1 comprises base B1 and quaternary ammonium ion Q1 or base B1 and organic sulfonate S1, preferably BCC1 comprises base B1 and quaternary ammonium ion Q1. B1 contains alkali metal cations and / or ammonium cations and has a pK of 1 to 10 at 25°C. b The compound has a value where Q1 contains an ammonium cation containing 6 to 30 carbon atoms, and S1 contains at least 7 carbon atoms.

[0093] More preferably, Q1 is a general structure R 1 R 2 R 3 R 4 Having NX, in the formula, - R 1 and R 2 These are the same or different alkyl groups having 1 to 12 carbon atoms, preferably 1 to 10, more preferably 1 to 7, even more preferably 1 to 6, particularly preferably 1 to 5, and most preferably 1 to 4 carbon atoms, and the alkyl group can be linear, branched, cyclic saturated or unsaturated, most preferably linear saturated alkyl groups. - R 3 The alkyl group is selected from the group consisting of alkyl groups having 1 to 12 carbon atoms, preferably 1 to 10, more preferably 1 to 7, even more preferably 1 to 6, particularly preferably 1 to 5, and most preferably 1 to 4 carbon atoms; aryl groups having 6 to 14 carbon atoms, preferably 6 to 12, and most preferably 6 to 10 carbon atoms; and aralkyl groups having 7 to 14 carbon atoms, preferably 7 to 12, and most preferably 7 to 10 carbon atoms. The alkyl group can be linear, branched, cyclic, saturated, or unsaturated, most preferably linear and saturated. - R 4 The alkyl group is selected from the group consisting of alkyl groups having 3 to 12 carbon atoms, preferably 3 to 10, more preferably 3 to 7, and most preferably 4 to 6 carbon atoms; aryl groups having 6 to 14 carbon atoms, preferably 6 to 12, and most preferably 6 to 10 carbon atoms; and aralkyl groups having 7 to 14 carbon atoms, preferably 7 to 12, and most preferably 7 to 10 carbon atoms. The alkyl group can be linear, branched, cyclic, saturated, or unsaturated, most preferably linear and saturated. - X is selected from the group consisting of carbonates, bicarbonates, acetates, hydroxides, and halides, the halides are preferably selected from chlorides and bromides, bisulfates, and alkyl sulfates, and the alkyl sulfates are preferably selected from methyl sulfates and ethyl sulfates.

[0094] More specifically, Q1 is a general structure R 1 R 2 R 3 R 4 Having NX, in the formula, R 1 ~R 4 The quaternary ammonium cation is selected such that the total number of carbon atoms in it is 6 to 14, preferably 7 to 14, more preferably 8 to 13. or R 1 ~R 4 The quaternary ammonium cation is selected such that the total number of carbon atoms in it is 15 to 30, preferably 15 to 28, more preferably 15 to 24, even more preferably 16 to 22, and most preferably 16 to 20.

[0095] BCC2 contains the base B2 and the quaternary ammonium ion Q2, where B2 has a pK of less than 1 at 25°C. b The value is such that Q2 contains an ammonium cation comprising 6 to 14 carbon atoms, preferably 7 to 12 carbon atoms, when the ammonium cation contains a benzyl residue.

[0096] More preferably, Q2 is a general structure R 1 R 2 R 3 R 4 Having NX, in the formula, - R 1 ~R 3 These are alkyl groups that are the same or different, having 1 to 6 carbon atoms, preferably 1 to 5, more preferably 1 to 4, even more preferably 1 to 3, particularly preferably 1 or 2, and most preferably 1. The alkyl group can be linear, branched, cyclic, saturated or unsaturated, and most preferably a linear saturated alkyl group. - R4 The alkyl group is selected from the group consisting of alkyl groups having 3 to 11 carbon atoms, preferably 3 to 10, more preferably 3 to 8, and most preferably 4 to 6 carbon atoms; aryl groups having 6 to 11 carbon atoms, preferably 6 to 10, and most preferably 6 to 8 carbon atoms; and aralkyl groups having 7 to 11 carbon atoms, preferably 7 to 10, and most preferably 7 to 9 carbon atoms. The alkyl group can be linear, branched, cyclic, saturated, or unsaturated, and most preferably a linear saturated alkyl group. - X is selected from the group consisting of bicarbonates, carbonates, acetates, hydroxides, and halides, the halides are preferably selected from chlorides and bromides, bisulfates, and alkyl sulfates, and the alkyl sulfates are preferably selected from methyl sulfates and ethyl sulfates.

[0097] More specifically, Q2 is a general structure R 1 R 2 R 3 R 4 Having NX, in the formula, R 4 Unlike benzyl residues, R 1 ~R 4 The quaternary ammonium cation is selected such that the total number of carbon atoms in it is 6 to 14, preferably 7 to 14, more preferably 8 to 13. or R 4 It is a benzyl residue, and R 1 ~R 3 The quaternary ammonium cation is selected such that the total number of carbon atoms in it is 6 to 12, preferably 7 to 12, and more preferably 8 to 11.

[0098] BCC3 contains base B3 and quaternary ammonium ion Q3, and base B3 has a pK of less than 1 at 25°C. b Q3 has a value and contains an ammonium cation comprising 15-30, preferably 15-28, more preferably 15-24, even more preferably 16-22, and most preferably 16-20 carbon atoms.

[0099] More preferably, Q3 is a general structure R 1R 2 R 3 R 4 Having NX, in the formula, - R 1 and R 2 These are the same or different alkyl groups having 1 to 12 carbon atoms, preferably 1 to 10, more preferably 1 to 7, even more preferably 1 to 6, particularly preferably 1 to 5, and most preferably 1 to 4 carbon atoms, and the alkyl group can be linear, branched, cyclic, saturated or unsaturated, most preferably a linear saturated alkyl group. - R 3 The alkyl group is selected from the group consisting of alkyl groups having 1 to 12 carbon atoms, preferably 1 to 10, more preferably 1 to 7, even more preferably 1 to 6, particularly preferably 1 to 5, and most preferably 1 to 4 carbon atoms; aryl groups having 6 to 14 carbon atoms, preferably 6 to 12, and most preferably 6 to 10 carbon atoms; and aralkyl groups having 7 to 14 carbon atoms, preferably 7 to 12, and most preferably 7 to 10 carbon atoms. The alkyl group can be linear, branched, cyclic, saturated, or unsaturated, and most preferably a linear saturated alkyl group. - R 4 The alkyl group is selected from the group consisting of alkyl groups having 3 to 12 carbon atoms, preferably 3 to 10, more preferably 3 to 7, and most preferably 4 to 6 carbon atoms; aryl groups having 6 to 14 carbon atoms, preferably 6 to 12, and most preferably 6 to 10 carbon atoms; and aralkyl groups having 7 to 14 carbon atoms, preferably 7 to 12, and most preferably 7 to 10 carbon atoms. The alkyl group can be linear, branched, cyclic, saturated, or unsaturated, and most preferably a linear saturated alkyl group. - X is selected from the group consisting of carbonates, bicarbonates, acetates, hydroxides, and halides, the halides are preferably selected from chlorides and bromides, bisulfates, and alkyl sulfates, and the alkyl sulfates are preferably selected from methyl sulfates and ethyl sulfates.

[0100] 4.4 Crude product R H As a result of step a, polyol P PU , amine A PU Crude product R containing water W and at least one base BH You can obtain this.

[0101] Hydrolysis crude product R H is the organic phase P O and aqueous phase P W Includes.

[0102] In a preferred embodiment, the organic phase P O This is the crude product R H Polyol P formed in step a as part of the process PU The main part and the crude product R H Amine A is formed in step a as part of the process. PU Includes the main part of it.

[0103] "Crude product R H Polyol P formed in step a as part of the process PU The main part of the crude product R H Polyol P formed in step a as part of the process PU This means more than 50 mol%, preferably at least 60 mol%, more preferably at least 70 mol%, more preferably at least 80 mol%, more preferably at least 90 mol%, more preferably at least 99 mol%, and even more preferably essentially all.

[0104] "Crude product R H Amine A is formed in step a as part of the process. PU The main part of the crude product R H Amine A is formed in step a as part of the process. PU This means more than 50 mol%, preferably at least 60 mol%, more preferably at least 70 mol%, more preferably at least 80 mol%, more preferably at least 90 mol%, more preferably at least 99 mol%, and even more preferably essentially all.

[0105] water phase P W This is the crude product R after step a. H Essentially formed by water W and base B contained in the organic phase P OTypically, due to Nernst's partition law, which states that any compound is always partitioned between two immiscible phases, water W and base B are also present to some extent.

[0106] In particular, the crude product R after step a. H At least 75% by weight, preferably at least 95% by weight, of the water W contained in the aqueous phase P W While forming part of the organic phase P O It also contains water W, and the crude product R after step a. H It contains 25% by weight or less, preferably 5% by weight or less, of the water W contained in it.

[0107] In particular, the crude product R after step a. H At least 75% by weight of base B contained in aqueous phase P W While forming part of the organic phase P O This is the crude product R after step a. H It contains 25% by weight or less, preferably 5% by weight or less, of base B contained in it.

[0108] When a phase transfer catalyst is used in step a, in particular when at least one quaternary ammonium salt Q is used in step a, the organic phase P O In particular, at least a portion of the quaternary ammonium salt Q, or the decomposition product D formed from Q during the reaction in step a. Q This also includes.

[0109] In particular, water phase P W This is the crude product R after step a. H It contains the main portion of base B.

[0110] The method of the present invention results in the effective hydrolytic cleavage of urethane and urea bonds present in the PU being treated, and amine A PU and polyol P PU Generate P PU The polyether polyol is preferably a polyether polyol. In particular, when the PU is made using a chain extender or curing agent, a low molecular weight glycol or polyol P PU Diols different from amine A PUFurther products, such as diamines, which are different from the initial product, can also be obtained.

[0111] Similarly, since the method according to the present invention can be applied to the recycling of PU from a wide range of sources and waste, the PU subjected to the method according to the present invention is used to produce the hydrolysis crude product R H Crude product R obtained, particularly after step a. H included organic phase P O and aqueous phase P W It may contain further additives and processing aids.

[0112] Therefore, in a particular embodiment of the present invention, the crude product R obtained after step a. H The material contains at least one component C, where C is selected from the group consisting of foaming catalysts, inorganic fillers, polymer fillers, flame retardants, formate salts, carboxylates such as acetates, polydimethylsiloxanes, organic pigments, and polymer fillers, preferably SAN polymers.

[0113] Typically, foaming catalysts, inorganic fillers, polymer fillers, and organic pigments are organic phase P O These include formate, carboxylates such as acetate, polydimethylsiloxane, inorganic fillers, polymer fillers, preferably SAN polymers, and flame retardants, as well as aqueous phase P W It can be seen inside.

[0114] Therefore, in a preferred embodiment, (i) Crude product R obtained after step a. H included organic phase P O C is one or more components selected from the group consisting of foaming catalysts, inorganic fillers, polymer fillers, organic pigments, antioxidants, and dyes. O It further includes, and / or (ii) Crude product R obtained after step a. H *Aqueous phase P W C is one or more components selected from the group consisting of dyes, polydimethylsiloxanes, polymer fillers, inorganic fillers, flame retardants, and carboxylates. WThe further comprising the carboxylate salt is preferably at least one of formate and acetate salts.

[0115] In the preferred embodiment (ii), P W Component C W The amount is minimized, preferably P W is component C W In order to not essentially include P O1 to R H Before, during, or after separation from component C, more preferably before or after separation from component C W At least a part, preferably all, of the aqueous phase P W It is even more preferable to separate it from.

[0116] In the preferred embodiment (i), P O1 Component C O The amount is minimized, preferably P O1 is component C O In order to not essentially include P O1 to R H Before, during, or after separation from component C, more preferably before or after separation from component C O At least a part, preferably all, of the organic phase P O It is even more preferable to separate it from.

[0117] In some embodiments, particularly when the PU subjected to step a. is only partially hydrolyzed in step a., the crude product may also include solid S. These solid S may be particles of the partially hydrolyzed PU, or components including additional polymer fillers (such as styrene-acrylonitrile polymers abbreviated as "SAN polymers"), for example, if the PU is composed of a polyol, particularly a polyether polyol, such polymers (SAN polymers) in dispersed or covalent form.

[0118] Therefore, the crude product R obtained after step a. H This optionally includes a solid S.

[0119] In a preferred embodiment, crude product R H The composition is as follows:

[0120] In this preferred embodiment, the crude product R obtained after step a. H The organic phase P inside O teeth, (α) Organic phase P O More than 40% by weight, preferably 45-90% by weight, more preferably 50-80% by weight, even more preferably 55-80% by weight, even more preferably 60-75% by weight, and most preferably 65% ​​by weight of polyol P PU Includes, (β) Organic phase P O Amine A in an amount of 10-40% by weight, preferably 15-35% by weight, more preferably 20-30% by weight, and most preferably 22-27% by weight, relative to the weight of [the product]. PU Includes, (γ) Organic phase P O The mixture contains water W in an amount less than 20% by weight, preferably 0.1 to 15% by weight, more preferably 1 to 10% by weight, even more preferably 3 to 8% by weight, and most preferably 5% by weight, relative to the weight of the mixture. (δ) Organic phase P O It contains less than 15% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, and most preferably 1 to 5% by weight of inorganic base B, (ε) When at least one quaternary ammonium salt Q is used as a phase transfer catalyst in step a, the organic phase P O A total of less than 15% by weight, preferably 0-10% by weight, more preferably 0.01-6% by weight, even more preferably 0.05-6% by weight, particularly preferably 0.5-4% by weight, and most preferably 1-2.5% by weight, consists of quaternary ammonium salt Q and decomposition products D of quaternary ammonium salt Q. Q It is composed of the sum of and D Q This corresponds to amine A Q and the corresponding alcohol P Q And, (ζ) The PU subjected to step a. is each compound C O If it contains organic phase PO Compound C in a total amount of less than 15% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, and most preferably 1 to 5% by weight, relative to the weight of [the other compound]. O Contains compound C O It is selected from the group consisting of foaming catalysts, inorganic fillers, polymer fillers, organic pigments, antioxidants, and dyes. The sum of the amounts of components (α) to (ζ) and any additional components that may be present is the amount of organic phase P. O This can reach a maximum of 100% by weight.

[0121] Alternatively or additionally, preferably additionally, the crude product R obtained after step a. H Water phase P inside W teeth, (η) Water phase P W Less than 4% by weight, preferably 0-2% by weight, more preferably 0-1% by weight, and most preferably 0-0.1% by weight of polyol P PU Includes, (θ) Water phase P W Amine A in an amount of 0-3% by weight, preferably 0-2% by weight, more preferably 0.001-1% by weight, even more preferably 0.001-0.5% by weight, and most preferably 0.01-0.1% by weight, relative to the weight of PU Includes, (ι)Aqueous phase P W It contains 40-80% by weight, preferably 45-70% by weight, more preferably 50-60% by weight, and most preferably 55-65% by weight of water W relative to the weight of the product. (κ)Aqueous phase P W It contains 20-60% by weight, preferably 25-50% by weight, more preferably 30-40% by weight, and most preferably 35-45% by weight of inorganic base B, relative to the weight of (λ) When at least one quaternary ammonium salt Q is used as a phase transfer catalyst in step a, the aqueous phase P W A total of 0 to 3% by weight, preferably 0 to 2% by weight, more preferably 0.001 to 1% by weight, even more preferably 0.001 to 0.5% by weight, and most preferably 0.01 to 0.1% by weight, is composed of quaternary ammonium salt Q and decomposition products D of quaternary ammonium salt Q. QIt is composed of the sum of and D Q This corresponds to amine A Q and the corresponding alcohol P Q And, (μ) The PU subjected to step a. is each compound C W If it contains, aqueous phase P W Compound C in a total amount of less than 15% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, and most preferably 1 to 5% by weight, relative to the weight of [the other compound]. W Contains compound C W The filler is selected from the group consisting of carboxylates (formate, acetate, etc.), polydimethylsiloxane, polymer fillers, preferably SAN polymers, flame retardants, dyes, and inorganic fillers. The sum of the amounts of components (η)~(μ) and any further components is given by the aqueous phase P W This can reach a maximum of 100% by weight.

[0122] Quaternary ammonium salt Q has a general structure R 1 R 2 R 3 R 4 If NX is present, the corresponding amine A Q Preferably R 1 R 2 R 3 N, R 1 R 3 R 4 N, R 1 R 2 R 4 N, R 2 R 3 R 4 N, R 1 R 2 NH, R 1 R 3 NH, R 1 R 4 NH, R 2 R 3 NH, R 2 R 4 NH, R 3 R 4 NH, R 1 -NH2, R 2 -NH2, R 3 -NH2, R 4A compound selected from the group consisting of -NH2, and the corresponding alcohol P Q Preferably R 1 -OH, R 2 -OH, R 3 -OH, R 4 It is a compound selected from the group consisting of -OH groups.

[0123] 4.5 Reaction conditions in step a. According to the present invention, step a is carried out by contacting water W, at least one base B, and PU to be subjected to the hydrolysis reaction. This contact is carried out in particular in a reactor in which each reactant is mixed and reacts with each other. Such a reactor is selected from a continuous stirred-tank reactor and an autoclave.

[0124] In an alternative embodiment, step a. may also be carried out in a reactor specifically designed for continuous processing, such as an extruder (e.g., screw extruder, planetary gear extruder) or a kneader.

[0125] The reaction conditions applied in step a are known to those skilled in the art.

[0126] The partial hydrolysis in step a is preferably carried out at a temperature of 90°C to 220°C, preferably 100°C to 200°C, more preferably 110°C to 200°C, even more preferably 120°C to 200°C, and most preferably 140°C to 200°C.

[0127] The hydrolysis in step a. is more preferably carried out for 30 minutes to 20 hours, preferably 30 minutes to 16 hours, more preferably 30 minutes to 14 hours, even more preferably 45 minutes to 10 hours, particularly preferably 60 minutes to 8 hours, and even more preferably 60 minutes to 6 hours.

[0128] The hydrolysis in step a. is more preferably carried out under atmospheric pressure or an increased pressure, particularly under a pressure of 1 to 30 bar abs., preferably 2 to 20 bar abs., and more preferably 3 to 15 bar abs.

[0129] 4.6 Grinding process (optional) To facilitate handling of PU in step a, it is preferable to perform a prior step (i.e., before step a) in which the PU is subjected to at least one pretreatment in which the PU is pulverized. This pulverization is more preferably selected from the group consisting of shredding, micronization, and grinding. This preferred pretreatment step yields PU in the form of relatively small particles or granules. This pretreatment step is particularly advantageous when the PU subjected to the method of the present invention is in solid form. In this case, the first micronization step is extremely advantageous in order to maximize the surface area available for the reaction and thereby reduce the reaction time required to achieve the desired level of hydrolysis.

[0130] In a further preferred embodiment of the present invention, particularly when the PU subjected to the method according to the present invention is a foam, the PU may be partially or completely compressed before being subjected to step a.

[0131] The progress of hydrolysis of PU in step a. can be monitored by nuclear magnetic resonance ("NMR") or infrared ("IR") spectroscopy. In particular, these methods can be used to monitor the amount of urethane groups in the PU used in step a. and the amount of urethane groups in the PU after the reaction has proceeded.

[0132] In a preferred embodiment, step a. is carried out until the amount of urethane groups in the PU initially subjected to step a. is reduced by at least 10%, more preferably at least 25%, more preferably at least 40%, more preferably at least 51%, more preferably at least 75%, more preferably at least 85%, more preferably at least 92%, and more preferably at least 99%.

[0133] More preferably, step a is carried out until the PU group is essentially undetectable.

[0134] 5. Process b. According to step b of the method of the present invention, organic phase P Oat least part of P O1 Crude product R H Separated from, P O1 is polyol P PU , amine A PU , contains water W.

[0135] In step b, "R H From at least part P O1 "To separate the crude product R" means to separate the crude product R H The complete aqueous phase P is included in it. W From the complete organic phase P O This also includes embodiments in which P is essentially separated. O1 is P O It is essentially identical to that.

[0136] After step b, the crude product R obtained after step a. H Organic phase P that is not in direct contact with the remainder O1 This is obtained. In other words, organic phase P O1 This is the aqueous phase P obtained after Step a. W It is separated from at least a portion of it.

[0137] Crude product R from step b. H Organic phase P from O at least part of P O1 The separation can be carried out according to the knowledge of those skilled in the art.

[0138] In particular, the separation in step b. can be carried out using a separatory funnel and / or by centrifugation or decantation.

[0139] Crude product R H If it contains solid S, P O at least part of P O1 to R H Before or after separation from the crude product R H At least a portion of the solid S contained in the crude product R H , especially organic phase P O and aqueous phase P W At least one phase selected from, preferably an organic phase P OIt is preferable to separate it from.

[0140] R H , especially organic phase P O and aqueous phase P W This preferred separation of solid S from at least one phase selected from the above can be carried out, in accordance with the knowledge of those skilled in the art, by at least one method selected from filtration, decantation, and centrifugation.

[0141] After step b, crude product R H Organic phase P separated from the rest of the O at least part of P O1 This is obtained. After step b, the crude product R is still obtained. H The aqueous phase contained herein is referred to as "P W1 It is abbreviated as "".

[0142] In particular, the organic phase P obtained in this way O1 The composition is as follows: Crude product R obtained after step a. H included organic phase P O It corresponds to the composition of [the subject].

[0143] Therefore, in a preferred embodiment, the organic phase P obtained after step b. O1 The composition is, (α1) Organic phase P O1 More than 40% by weight, preferably 45-90% by weight, more preferably 50-80% by weight, even more preferably 55-80% by weight, even more preferably 60-75% by weight, and most preferably 65% ​​by weight of polyol P PU Includes, (β1) Organic phase P O1 Amine A in an amount of 10-40% by weight, preferably 15-35% by weight, more preferably 20-30% by weight, and most preferably 22-27% by weight, relative to the weight of [the product]. PU Includes, (γ1) Organic phase P O1 The mixture contains water W in an amount less than 20% by weight, preferably 0.1 to 15% by weight, more preferably 1 to 10% by weight, even more preferably 3 to 8% by weight, and most preferably 5% by weight, relative to the weight of the mixture. (δ1)Organic phase P O1 It contains less than 15% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, and most preferably 1 to 5% by weight of inorganic base B, (ε1) When at least one quaternary ammonium salt Q is used as a phase transfer catalyst in step a, the organic phase P O1 A total of less than 15% by weight, preferably 0-10% by weight, more preferably 0.01-6% by weight, even more preferably 0.05-6% by weight, particularly preferably 0.5-4% by weight, and most preferably 1-2.5% by weight, consists of quaternary ammonium salt Q and decomposition products D of quaternary ammonium salt Q. Q It is composed of the sum of and D Q This corresponds to amine A Q and the corresponding alcohol P Q And, (ζ1) The PU subjected to step a. is each compound C O If it contains organic phase P O1 Compound C in a total amount of less than 15% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, and most preferably 1 to 5% by weight, relative to the weight of [the other compound]. O Contains compound C O It is selected from the group consisting of foaming catalysts, inorganic fillers, polymer fillers, organic pigments, antioxidants, and dyes. The sum of the amounts of components (α1) to (ζ1) and any additional components present is the amount of organic phase P O1 This can reach a maximum of 100% by weight.

[0144] Step b. P obtained after the process O1 It is still essential that it contains water. Therefore, logically, the crude product R H As part of the process, P obtained after step a. O However, this inevitably means that it also includes water. This is R H The main part of the water inside is naturally the aqueous phase P. W It forms an organic phase P O According to Nernst's distributive law, water can be found even inside.

[0145] In addition, after step b, P O1 The water (and base B) contained in it undergoes phase separation into aqueous phase P W This can be carried over from previous processes, and may also be due to inaccurate separation methods. Such slight inaccuracies in phase separation can be minimized, but they cannot always be completely avoided. However, R H P from O1 It is preferable that a clear and precise separation is achieved in step a.

[0146] Preferably, the separation is carried out by at least one separation method selected from the group consisting of centrifugation, filtration, decantation, and membrane treatment.

[0147] The method of the present invention is advantageous in several respects, one of which is resource efficiency. To further improve this resource efficiency, the method of the present invention, in a preferred embodiment, involves step b. H P from O1 After separation, R H *Aqueous phase P W This method is characterized by using at least a portion of the hydrolysis in step a.

[0148] In particular, in process b, P O1 to R H Aqueous phase P obtained after separation from W1 At least a portion of the water contained in and / or at least a portion of base B is used for hydrolysis in step a.

[0149] For example, in process b, P O1 to R H R obtained after separation from H *Aqueous phase P W1 At least a portion of this may be supplied to the hydrolysis reaction mixture in which hydrolysis is carried out in step a.

[0150] P W1 In an alternative embodiment for recirculating water and base B from the aqueous phase, this aqueous phase may be subjected to distillation, and the water thus distilled may be supplied to the hydrolysis of step a., and / or PW1 The base B contained in each phase P W1 It can be obtained by crystallization. This allows P W1 The separate recovery of water and base B is achieved, and it becomes possible to supply water and base B to the reaction mixture in step a. separately from each other, and to measure the amount of one compound independently of the other.

[0151] 6. Process c. According to step c of the method of the present invention, at least a portion of water W and amine A PU At least a portion of it is distilled into P O1 It is separated from.

[0152] In a preferred embodiment of step c, amine A PU A portion of the water W and at least a portion of the P are distilled. O1 Separate from.

[0153] After step c, water vapor V and amine A PU Fraction F containing A , and polyol P PU , optionally amine A PU and optionally an organic phase P containing water W. O2 This yields "Polyol P PU , optionally amine A PU and optionally an organic phase P containing water W. O2 " is the organic phase P O2 Polyol P PU Including, organic phase P O2 Optionally, amine A PU Including, and organic phase P O2 It should be understood that this optionally includes water W.

[0154] Preferably, P O2 is polyol P PU , amine A PU and optionally containing water W.

[0155] Distillation step c can be carried out according to the knowledge of those skilled in the art. Essential requirements are that after step c, water vapor V and fraction F A and organic phase P O2 These are obtained as separate phases, that is, without direct contact with each other.

[0156] In a preferred embodiment, step c includes at least two distillation steps c1 and c2, wherein in step c1, at least a portion of the water W is distilled into P O1 Separated from water vapor V and residual organic phase P O1* Having obtained, in step c2, amine A PU At least a portion, preferably a portion, of P is distilled O1* Separated from, fraction F A and residual organic phase P O2 To obtain.

[0157] In step c, particularly step c1, "water vapor V" is obtained. Therefore, water is preferably at least one amine A PU It has a lower boiling point than [the other substance]. Preferably, distillation by step c1 is performed at temperature T c1 ≤220℃, preferably T c1 ≤200℃ and pressure p c1 ≤1 bar abs., preferably 0 <p c1 ≤1000mbar abs., more preferably 1 ≤ p c1 ≤500mbar abs., most preferably 20≤p c1 Perform the test at a bar of ≤300 mbar.

[0158] Alternatively or additionally, preferably additionally, in step c, particularly step c2, amine A PU Fraction F containing A It is preferable to obtain at least one amine A. PU Preferably, at least one polyol P PU It has a lower boiling point than [the other substance]. Preferably, distillation by step c2 is performed at temperature T c2 ≤220℃, preferably T c2 ≤200℃ and pressure p c2≤1 bar abs., preferably 0 <p c2 ≤1000mbar abs., more preferably 0 ≤ p c2 ≤100mbar abs., most preferably 0 ≤ p c2 Perform the test at a bar of ≤20 mbar.

[0159] In step c2, it is preferable that the distillation temperature is higher than the distillation temperature in step c1, and the distillation pressure in step c2 is less than or equal to the distillation pressure in step c1. Therefore, T c1 <T c2 and p c1 ≧p c2 It is preferable that this be the case.

[0160] These conditions require at least one type of amine A PU Equation (II): H2N-W 1 -NH2[wherein, W 1 If it has a general structure due to the above-described structure (II-B), preferably at least one amine A PU This is particularly advantageous when the substance is toluenediamine ("TDA").

[0161] The residual organic phase P obtained after step c1 and subjected to step c2. O1* The composition of the P used in step c1 is particularly important. O1 Corresponding to the composition of P O1* The amount of water is P O1 Less than the amount of water contained in ., arbitrarily, P O1* Amine A contained in PU The amount is P O1 Amine A contained in PU It is less than that amount.

[0162] The residual organic phase P obtained after step c2 and subjected to step d. O2 The composition of the P used in step c2 is particularly important. O1* Corresponding to the composition of P O2 Amine A contained in PU The amount is P O1* Amine A contained in PU Less than the amount of P. O2The amount of water is P O1* It is less than the amount of water contained in it.

[0163] In particular, step c1 is carried out at least partially inside the distillation column K1.

[0164] Any desired distillation column known to those skilled in the art may be used as distillation column K1 (or distillation column K2 as described below) in this preferred embodiment of step c. of the present method. Distillation columns K1 and K2 preferably include internal structures. Suitable internal structures include, for example, trays, unstructured packing, or structured packing. Trays used are typically bubble cap trays, sieve trays, valve trays, tunnel cap trays, or slot trays. Unstructured packing is generally a bed of random packing elements. Random packing elements used are typically Raschig rings, pole rings, Berl saddles, or Intalox® saddles. Structured packing is sold under the trade name Sulzer Mellapak®, for example. Apart from the internal structures described above, further suitable internal structures are known to those skilled in the art and may be used in the same manner.

[0165] In a further preferred embodiment, step c2 is carried out at least partially in at least one apparatus selected from a short-pass evaporator, a thin-film evaporator, and a distillation column K2, wherein the distillation column K2 is different from the distillation column K1.

[0166] In a preferred embodiment, at least one amine A PU The boiling point of is higher than that of water, and it contains at least one polyol P PU The boiling point of at least one amine A PU It is higher than the boiling point of [unclear].

[0167] P O1 Decomposition product D of quaternary ammonium salt Q and / or quaternary ammonium salt Q Q In embodiments including these, they are distilled in an additional distillation step and / or together with water vapor W and P O1 It is preferable to separate from P.O1 Decomposition product D of quaternary ammonium salt Q and / or quaternary ammonium salt Q Q In embodiments in which steps c1 and c2 are performed, the quaternary ammonium salt Q and / or the decomposition product D of the quaternary ammonium salt Q are included. Q , a more preferred decomposition product D of quaternary ammonium salt Q Q Preferably, at least a portion of it is separated by distillation during step c1, i.e., following or simultaneously with the water vapor V.

[0168] Step c1. The resulting water vapor V is the decomposition product D of the quaternary ammonium salt Q and / or quaternary ammonium salt Q. Q If contaminated, it is preferably subjected to an additional distillation step before being used as stripping gas in step d.

[0169] Preferably, at least part of step c, and especially at least step c2, is carried out in an atmosphere having an oxygen content of 0 to 21 volume%, preferably 0 to 8 volume%, more preferably 0 to 1 volume%, and most preferably 0 to 0.1 volume%, preferably an atmosphere containing only product vapor and one or more inert gases.

[0170] This results in recycled amine A PU and recycled polyol P PU The purity of the material is further improved, making it particularly useful for recycling for the manufacture of PU (polyurethane).

[0171] 7. Process d. According to step d of the method of the present invention, organic phase P O2 at least part of P O3 The material is purified by stripping. A feature of the present invention is that in step d, water vapor V is used as the stripping gas, and P O3 It is used in the opposite direction.

[0172] This procedure allows P O1Water isolated from the solution can be used, and there is no need to add additional water to perform the stripping step d.

[0173] This stripping step d is the organic phase P obtained after step c, particularly after step c2. O2 at least part of P O3 This is advantageous because it is further purified. In a preferred embodiment, this phase P O2 is amine A PU and / or quaternary ammonium salt Q and / or decomposition product D Q It still includes, in particular, P O2 is amine A PU It still includes P O2 These impurities are removed at least partially, and preferably completely, in step d.

[0174] "Stripping" is a physical separation process known to those skilled in the art, used in many fields of prior art for the purification of liquids (for example, M. Kriebel: “Absorption, 2. Design of Systems and Equipment”, Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, chap. 3, Wiley VCH, Weinheim October 2008).

[0175] In the context of the present invention, the gas phase, i.e., water vapor V, is the phase to be purified, i.e., P O3 The phase that comes into contact with or is purified in a countercurrent, namely, P O3 The water vapor V comes into contact with the water vapor in a countercurrent under a reduced pressure of less than 1 bar. According to the present invention, this contact is carried out particularly inside the distillation column, more preferably inside column K1, when column K1 is used in step c.

[0176] In this invention, stripping is preferably performed under reduced pressure of less than 1 bar. Optionally, in addition to water vapor V, an additional inert stripping gas can be used countercurrently. This additional inert stripping gas is preferably selected from the group consisting of noble gases and nitrogen. Similarly, in addition to the water vapor V obtained in step c, additional water vapor is used in step d to P O3 The purification process can be further improved.

[0177] The stripping temperature can be controlled by a person skilled in the art by setting an appropriate negative pressure inside the tower using conventional methods.

[0178] The pressure in step d. according to the present invention is preferably less than 1 bar abs., particularly in the range of 1 to 500 mbar abs., and more preferably in the range of 20 to 300 mbar abs.

[0179] Step d is preferably carried out at a temperature of 250°C or lower, and more preferably 200°C or lower.

[0180] In particular, organic phase P O3 In step d, the material is used at a temperature of 200°C or lower, preferably 150°C to 200°C, and the water vapor V is used in step d at a temperature of 250°C or lower, preferably 180°C to 200°C.

[0181] P in process d. O3 Purification of P O3 This can be improved by increasing the surface area of ​​the tower K1 in the portion of the tower K1 that comes into contact with the water vapor V during stripping. Preferably, for this purpose, step d of the method according to the present invention P O3 The material is passed at least partially through the floor of the packing elements or the structured packing within column K1. For this purpose, all packing elements and structured packings known to those skilled in the art from the prior art relating to distillation and absorption processes are suitable. Alternatively, stripping can be carried out in a fall-film evaporator or a thin-film evaporator. These apparatuses are known to those skilled in the art from the prior art.

[0182] It is preferable to carry out at least a portion of steps d and c in the same distillation column K1. In embodiments in which step c includes steps c1 and c2, it is even more preferable to carry out steps c1 and d in the same distillation column K1.

[0183] In this preferred embodiment, resource efficiency is further improved because only one tower K1 is used in the two steps c. and d. In addition, the steam obtained in step c. can be guided towards the top of tower K1 within tower K1 so that the steam V does not need to be condensed and evaporated. In this case, the P supplied to step d. O3 It is preferably supplied from the top of tower K1.

[0184] Organic phase P used in step d. O3 However, amine A PU , amine decomposition product D Q At least one amine A selected from * If it includes P O3 All of the amine A inside * The amount is reduced to less than 5% by weight, preferably less than 1% by weight, more preferably less than 0.5% by weight, even more preferably less than 0.3% by weight, and most preferably less than 0.1% by weight during step d.

[0185] 8. Optional purification process In a preferred embodiment, the method according to the present invention provides fraction F obtained after step c. A Further purification is performed, and / or the organic phase P obtained after step d. is obtained. O3 This includes at least one further step e. to further purify the product.

[0186] Any step e is preferably selected from the group consisting of filtration, fractional distillation, crystallization, membrane treatment, and solvent extraction.

[0187] In particular, in step e, at least one impurity selected from water, polyols and light alcohols, catalytic decomposition products, amine oxidation products, fillers, additives, preferably pigments and colorants, and impurities from PU foam production, each of the following is F A and / or P O3 It is removed from.

[0188] 9. Recycling Process The method according to the present invention involves polyol P PU and amine A PU This is a resource-efficient method that provides high purity. Therefore, any compound obtained by this method can be efficiently recycled and used in the synthesis of PU.

[0189] Preferably, polyol P PU and amine A PU At least one of these compounds selected from is subsequently used to produce a new PU, preferably a PU foam. Therefore, in a preferred embodiment of this method, fraction F is used in step c of the method of the present invention. A Amine A obtained from PU In the additional step f, amine A PU The amino group is subjected to a reaction in which it is converted to an isocyanate group, preferably via phosgenation. Such phosgenation is known to those skilled in the art and is described, for example, in RJ Slocombe, EE Hardy, JH Saunders, RL Jenkins, J. Am. Chem. Soc. 1950, 72, 1888-1891 and HJ Twitchett, Chem. Soc. Rev. 1974, 3, 209-230.

[0190] A more preferred embodiment of the present invention is a method (particularly step d.) according to the present invention for producing polyurethane, particularly polyurethane foam, and the polyol P obtained by this method. PU and / or use of the isocyanate obtained in step f.

[0191] Polyol P obtained by the method according to the present invention (especially step d) for producing polyurethane, particularly polyurethane foam. PU Furthermore, the use of the isocyanate obtained in step f is even more preferable. In this even more preferred embodiment, the polyol P obtained by the method according to the present invention (particularly step d) is even more preferable. PU Most preferably, the isocyanates obtained in step f. are polymerized with each other to produce polyurethane, particularly polyurethane foam. [Examples]

[0192] 1. Hydrolysis reaction PU waste containing polymers of 2,4- and 2,6-toluene diisocyanates and polyether polyols, which are polymers of ethylene oxide and 1,2- and 1,3-propylene oxides, is shredded.

[0193] Next, 10 kg of these PU particles are mixed in a steel kettle with 97.3 kg of a 40 wt% aqueous solution of K2CO3 and 0.956 kg of tetrabutylammonium bisulfate. The resulting mixture is heated to 150°C and stirred for 4 hours. The crude product thus obtained is allowed to cool to room temperature. This contains a solid, an aqueous phase, and an organic phase. After the organic phase is allowed to settle in the reactor, it is separated from the aqueous phase and the solid.

[0194] The organic phase contains approximately 5% by weight of water, approximately 22% by weight of TDA, and approximately 65% ​​by weight of polyether polyol.

[0195] 2. Post-treatment of the organic phase The organic phase is post-treated by distillation in an apparatus as shown in the diagram.

[0196] In particular, the organic phase is distilled in a distillation column. <4> Evaporator connected <2> To flow <1> It is supplied as a distillation column. <4> two fillers <41> , <44> And the top filling <44> Liquid collector at the bottom <45> It is equipped with the following.

[0197] Evaporator <2> Then, the organic phase is heated to 200°C, <4> The pressure is 50-200 mbar abs. <4> So, water vapor <3> The bottom filling <41> Passing through the tower <4> internal condenser <42> This partially condenses, thereby separating impurities in the water vapor, particularly low-boiling and high-boiling compounds, such as TDA, or amine decomposition products of the phase transfer catalyst (such as tributylamine "TriBA"), from the water vapor by condensation, and piping <7> It is discharged through [a certain mechanism]. Furthermore, some of the condensate is discharged through [a certain mechanism]. <9> via supply flow <14> From the tower <4> It is recycled into the piping. <8> Additional water can be supplied to this reflux via water vapor. <3> (For example, tower <4> Internal heating means <43> (By) optionally heated, the top filling <44> It passes through.

[0198] Next, the evaporator <2> surviving liquid distillation residue <5> It is then led to a short-film evaporator (not shown), where the TDA is distilled at 190°C and 4 mbar abs. <5> It is removed from.

[0199] Liquid distillation residue remaining from this second distillation in the short film evaporator <6> It mainly contains polyols. This is a preheater. <10> After being heated to 160°C, the tower <4> It is supplied to the top of the tower. <4> At the top, the organic phase <6> water vapor <3> The stripping is performed in a countercurrent. This final stripping step removes amine compounds, particularly impurities such as TDA and TriBA, from the polyol phase. <6> Essentially removes it from. Then, high-purity polyol <11> Next, the polyol phase is obtained. <6> Water vapor containing impurities from the tower <4> Flow at the top <13> It is discharged as steam. This steam is then used in a condenser. <12> Condensation occurs via piping, and preferably impurities are further removed. <8> via tower <4> It is possible to supply it.

[0200] 3. Advantages compared to conventional methods This procedure offers several advantages compared to prior art methods in which the distillation of water / amines such as TDA / stripping of the polyol phase is performed separately or in which no specific details are described. In the method according to the present invention, the final purification step, i.e., the stripping required to obtain a highly purified polyol phase, is performed in a resource-efficient manner. Since the polyol phase thus obtained is extremely pure, the polyol can be used directly in polymerization with isocyanates to obtain polyurethane (PU).

[0201] 3.1) Organic phase <1> The water that evaporates from it becomes the organic phase <6> It is used directly for stripping. Therefore, there is no need to supply additional water to the process. Supply flow <8> This is entirely optional and not necessary to achieve a favorable effect.

[0202] 3.2) Steam obtained in the first distillation step <3> Since it is already in the "correct" condensation state, i.e., gaseous, it is the organic phase. <6> It can be used directly for stripping. Therefore, this method does not require energy for water coagulation / evaporation.

[0203] 3.3) This method can be carried out in a single column, with one column for every two distillation steps. <4> Because only this can be used, equipment can be reduced, which is even more advantageous.

Claims

1. At least one recycled polyol P from at least one type of polyurethane PU ＰＵ and at least one recycled amine A ＰＵ A method for manufacturing, a. By contacting the PU with water W and at least one base B, the PU is at least partially hydrolyzed to form a polyol P ＰＵ , amine A ＰＵ Crude product R comprising water W, at least one base B, and optionally a solid S Ｈ A step to obtain the crude product R Ｈ is organic phase P Ｏ and aqueous phase P Ｗ Processes including b. The crude product R Ｈ From the organic phase P Ｏ At least a part P Ｏ１ The step of separating, P Ｏ１ Is polyol P ＰＵ Amine A ＰＵ Including water W, the step, c. P Ｏ１ from at least a portion of the water W and the amine A ＰＵ At least a portion of it is separated by distillation, - Water vapor V, - Amine A ＰＵ Fraction F containing Ａ , - Polyol P ＰＵ , optionally amine A ＰＵ and optionally an organic phase P containing water W. Ｏ２ The process of obtaining d. The organic phase P Ｏ２ at least part of P Ｏ３ The process of purification by stripping. Includes, In step d, water vapor V is used as the stripping gas, P Ｏ３ A method characterized by being used in a countercurrent.

2. The method according to claim 1, characterized in that the at least one base B is selected from the group consisting of alkali metal phosphates, alkaline earth metal phosphates, alkali metal hydrogen phosphates, alkaline earth metal hydrogen phosphates, alkali metal carbonates, alkaline earth metal carbonates, alkali metal silicates, alkaline earth metal silicates, alkali metal bicarbonates, alkaline earth metal bicarbonates, alkali metal carboxylates, alkaline earth metal carboxylates, alkali metal sulfites, alkaline earth metal sulfites, ammonium hydroxide, alkali metal hydroxides, alkali metal oxides, alkaline earth metal oxides, and alkaline earth metal hydroxides.

3. The hydrolysis in step a is catalyzed by at least one phase transfer catalyst selected from the group consisting of quaternary ammonium salts Q and organic sulfonates. Preferably, the quaternary ammonium salt Q has a general structure R １ R ２ R ３ R ４ Having NX, in the formula, R １ , R ２ , R ３ and R ４ X is the same or different, and each is a hydrocarbyl group selected from alkyl, aryl, and arylalkyl groups, where X is selected from the group consisting of hydroxides, carbonates, bicarbonates, bisulfates, carboxylates, halides, and alkyl sulfates. The method according to claim 1 or 2, characterized in that...

4. Process b. R Ｈ P from Ｏ１ After separation, R Ｈ The aqueous phase P contained in Ｗ The method according to any one of claims 1 to 3, characterized in that at least a portion of it is used for hydrolysis by step a.

5. (i) Said crude product R Ｈ The organic phase P included in Ｏ However, one or more components C selected from the group consisting of foaming catalysts, inorganic fillers, polymer fillers, organic pigments, antioxidants, and dyes. Ｏ It further includes, and / or (ii) The crude product R Ｈ The aqueous phase P contained in Ｗ However, one or more components C selected from the group consisting of carboxylates, polydimethylsiloxanes, inorganic fillers, polymer fillers, flame retardants, and dyes. Ｗ Includes The method according to any one of claims 1 to 4, characterized in that

6. Step c comprises at least two distillation steps c1 and c2, wherein in step c1, at least a portion of the water W is distilled into P Ｏ１ Separated from this, water vapor V and residual organic phase P Ｏ１＊ Having obtained, in step c2, the amine A ＰＵ At least a portion of it is distilled into P Ｏ１＊ Separated from, fraction F Ａ and residual organic phase P Ｏ２ The method according to any one of claims 1 to 5, characterized by obtaining the following.

7. Step c1. Distillation column K １ The method according to claim 6, characterized in that it is performed within the premises.

8. Step c2. At least partially, the short-pass evaporator, thin-film evaporator, and distillation column K ２ The distillation is carried out in at least one apparatus selected from the distillation column K ２ Distillation column K １ The method according to claim 6 or 7, characterized in that it is different from the method described above.

9. - Distillation by step c1 at temperature T ｃ１ ≤220℃, preferably T ｃ１ ≤200℃ and pressure p ｃ１ ≤ 1 bar abs., preferably 0 < p ｃ１ ≤1000 mbar abs., more preferably 1 ≤ p ｃ１ ≤500 mbar abs., most preferably 20 ≤ p ｃ１ Perform the test with a bar limit of ≤300 mbar. - Distillation by step c2 at temperature T ｃ２ ≤220℃, preferably T ｃ２ ≤200℃ and pressure p ｃ２ ≤ 1 bar abs., preferably 0 < p ｃ２ ≤1000 mbar abs., more preferably 0 ≤ p ｃ２ ≤100 mbar abs., most preferably 0 ≤ p ｃ２ Perform the test with a bar of ≤20 mbar. Preferably, T ｃ１ <T ｃ２ katsu p ｃ１ ≧p ｃ２ That is The method according to any one of claims 6 to 8, characterized in that

10. The method according to any one of claims 1 to 9, characterized in that at least a portion of step c, preferably step c2, is carried out in an atmosphere having an oxygen content of 0 to 21 volume%, preferably 0 to 8 volume%, more preferably 0 to 1 volume%, and most preferably 0 to 0.1 volume%, preferably an atmosphere containing only product vapor and one or more inert gases.

11. At least a portion of step d. and at least a portion of step c., preferably step c1., in the same distillation column K １ The method according to any one of claims 1 to 10, characterized in that it is carried out by [method].

12. At least partial hydrolysis by step a. At a temperature of 90°C to 220°C, preferably 100°C to 200°C, more preferably 120°C to 200°C, and most preferably 140°C to 200°C, and / or Over a period of 30 minutes to 20 hours, preferably 30 minutes to 16 hours, more preferably 30 minutes to 14 hours, even more preferably 45 minutes to 10 hours, particularly preferably 60 minutes to 8 hours, and most preferably 60 minutes to 6 hours, and / or Under atmospheric pressure or increased pressure, particularly under pressures of 1 to 30 bar abs., preferably 2 to 20 bar abs., and more preferably 3 to 15 bar abs. The method according to any one of claims 1 to 11, characterized by performing the following.

13. Step c. Fraction F obtained afterwards Ａ Further purification is performed, and / or the purified organic phase P obtained after step d. Ｏ３ The method according to any one of claims 1 to 12, comprising at least one further step e. for further purification, wherein step e. is preferably selected from the group consisting of filtration, fractional distillation, crystallization, membrane treatment, and solvent extraction.

14. In step f, fraction F Ａ Amine A ＰＵ The amine A ＰＵ The method according to any one of claims 1 to 13, characterized by subjecting the amino group to a reaction that converts it to an isocyanate group, preferably via phosgenation.

15. At least one type of recycled polyol P ＰＵ A method for manufacturing polyurethane, particularly polyurethane foam, (1) At least one recycled polyol P according to the method described in any one of claims 1 to 13 ＰＵ The process of manufacturing (2) Optionally, a step of producing an isocyanate according to the method described in claim 14. (3) The at least one recycled polyol P ＰＵ A step of reacting with an isocyanate, preferably the isocyanate from step (2). Methods that include...

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