EP4363477A1

EP4363477A1 - Production of pu foams using recycled polyols

Info

Publication number: EP4363477A1
Application number: EP22738451.8A
Authority: EP
Inventors: Ralph Marquardt; Roland Hubel; Annegret Terheiden; Felix Mühlhaus
Original assignee: Evonik Operations GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2021-07-02
Filing date: 2022-06-28
Publication date: 2024-05-08
Also published as: CA3224253A1; CN117580884A; WO2023275033A1

Abstract

The invention relates to a method of producing PU foams by reacting (a) at least one polyol component that contains recycled polyol with (b) at least one isocyanate component in the presence of (c) one or more catalysts that catalyze the reactions of isocyanate-polyol and/or isocyanate-water and/or the isocyanate trimerization reaction, (d) at least one foam stabilizer and (e) optionally one or more chemical or physical blowing agents, and the recycled polyol contains 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4'-diaminodiphenylmethane in a total amount of 0.00001% to 0.4% by weight, preferably 0.00002% to 0.2% by weight, especially preferred 0.00005% to 0.1% by weight relative to the total of recycled polyol.

Description

Production of PU foams using recycled polyols

The invention is in the field of polyurethanes and relates to the production of PU foams using recycled polyols.

Due to their excellent mechanical and physical properties, polyurethanes are used in a wide variety of areas. The area of PU foams represents a particularly important market for the most diverse types of polyurethanes.

For the purposes of this invention, polyurethanes (PU) are understood to mean all reaction products starting from isocyanates, in particular from polyisocyanates, and corresponding isocyanate-reactive molecules, in particular polyols. This also includes, inter alia, polyisocyanurates, polyureas and isocyanate or polyisocyanate reaction products containing allophanate, biuret, uretdione, uretimine or carbodiimide.

Polyurethanes are now so widespread around the world that recycling these materials is becoming increasingly important. In the prior art, therefore, there are already different recycling processes for the utilization of polyurethane waste. The well-known chemical recycling processes such as hydrolysis, e.g. described in US Pat can be used. These polyol mixtures are generally referred to as recycled polyols.

In principle, efforts are being made to use the recycling polyols again for the production of polyurethanes. Against this background, it was the specific object of the present invention to enable the provision of PU foams using recycled polyols without impairing the quality of the resulting foams, especially when using larger amounts of recycled polyols compared to PU foams made with conventional polyols. The above object is solved by the subject matter of the invention. The subject of the invention is a process for the production of PU foams by reaction

(a) at least one polyol component comprising recycled polyol

(b) at least one isocyanate component in the presence of (c) one or more catalysts which promote the isocyanate-polyol and/or isocyanate-

catalyze water and/or isocyanate trimerization,

(d) at least one foam stabilizer and (e) optionally one or more chemical or physical blowing agents, the recycled polyol used being 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4 '-Diaminodiphenylmethane contains, in a total amount of 0.00001% to 0.4% by weight, preferably 0.00002% to 0.2% by weight, particularly preferably 0.00005% to 0.1% by weight. -% based on total recycled polyol.

The percentage by weight of 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4'-diaminodiphenylmethane in the recycling polyol is determined by analyzing 25 pL of a Sample for the preparation of which 25 mg

recycling polyol were dissolved in 25 ml of an aqueous 20 mmol/L diammonium hydrogen phosphate solution and acetonitrile (70:30), by HPLC in each case against an internal calibration line (detector: DAD 220 nm). The exact methods are explained in more detail in the example section below.

The subject of the invention makes it possible to provide polyurethane foams using larger amounts of recycled polyol, which correspond to the quality of conventional polyurethane foams, but which have been produced in the same way with conventional polyols.

Due to the achievable, high proportion of recycled polyol, the subject of the invention enables a significant increase in the total proportion of recycled raw materials in the polyurethane foams produced according to the invention compared to foams made from conventional or predominantly conventionally produced polyols, which is an important advance in terms of the recyclability of polyurethane foams.

A property of recycling polyols in general, which are obtained by processes of the prior art, is that they always have a proportion of primary aromatic amines, which are formed during the depolymerization of PU and can only be separated by complex large-scale separation methods such as distillation and/or or extraction and/or washing processes can be removed from the recycling polyols. However, these methods are often resource-intensive and result in high costs and waste. Possible residual contents of 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4'-diaminodiphenylmethane in recycling polyols can be problematic insofar as these aromatic amines are toxic on the one hand and can have a disruptive effect on PU production on the other. In particular, residual levels of 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4'-

In typical PU foam formulations, diaminodiphenylmethane totaling >0.4% by weight can lead to instability, even to the point of collapsing of the rising foam, so that satisfactory PU foams would then not be obtained. In addition, in molded foam applications of polyols with residual contents of 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4'-diaminodiphenylmethane with a total of >0.4% by weight, significant flow disturbances occur due to their rapid reaction with isocyanates and the resulting accelerated polymer build-up.

Surprisingly, it was found within the scope of this invention that recycling polyols, even with a varying content of 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4 '-Diaminodiphenylmethane of a total in the range from 0.00001 to 0.4% consistently even lead to PU foams of very good quality and that the resulting foams even with varying contents of 2,4-toluenediamine, 2,6- Toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4'-diaminodiphenylmethane in the recycling polyol total between 0.00001% and 0.4% by weight, preferably 0.00002% % to 0.2% by weight, particularly preferably 0.00005% to 0.1% by weight, based on the total recycling polyol, have comparable foam properties, even when large amounts of corresponding recycling polyols are used.

In a preferred embodiment of the invention, recycling polyols with the abovementioned content of 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4'-diaminodiphenylmethane are used , In foams with an index between 75 and 130, preferably between 85 and 125, more preferably between 90 and 120 and in particular between 95 and 115.

Surprisingly, it was also found as an additional advantage that in the case of such inventively produced foams with an index between 95 and 115 compared to a standard polyurethane foam (made without recycled polyol) comparable small amounts of 2,4-toluenediamine, 2,6 -Toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4'-diaminodiphenylmethane of a maximum total of 35 pg based on 1 g PU foam, preferably a maximum of 25 pg based on 1 g PU Foam, particularly preferably a maximum of 25 pg based on 1 g PU foam, in particular a maximum of 10 pg based on 1 g PU foam, can be detected in the VDA 278 emission test, which is particularly common for the automotive industry. VDA is the Association of the Automotive Industry ( www.vda.de ). The measuring principle and implementation of VDA 278 are explained in more detail in the examples.

As a further advantage, it was surprisingly found that the use of recycling polyols according to the invention with the abovementioned contents of 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4 ,4'-diaminodiphenylmethane can bring about an advantageous cell-opening effect in molded foam applications.

The invention also makes it possible to use large amounts of the appropriate recycling polyol, with no or only an insignificant reduction in foam quality or in a few cases even an improvement in foam quality compared to a foam made from conventionally produced polyol. It therefore corresponds to a preferred embodiment of the invention if more than 30% by weight, preferably more than 50% by weight, preferably more than 70% by weight, based on the total polyol component used, is more preferred in the process according to the invention more than 80% by weight, in particular more than 95 wt. or 4,4'-diaminodiphenylmethane, from a total of 0.00001% to 0.4% by weight, preferably 0.00002% to 0.2% by weight, particularly preferably 0.00005% to 0.1% by weight % based on the total recycled polyol.

The recycling polyol used is a polyol that results in particular from the recycling of polyurethane waste. Polyurethane waste includes all those polyurethanes, especially PU foams, which are no longer used but are intended for disposal. It therefore corresponds to a preferred embodiment of the invention if the recycling polyol used is a recycling polyol produced from polyurethane waste and/or recycling

Polymer polyol is preferably obtained from the depolymerization of PU foam, in particular of PU hot flexible foam (PU standard foam), viscoelastic PU foam and/or HR PU foam, the recycling polyol and/or recycling polymer polyol being separated by solvolysis , preferably by hydrolysis, aminolysis, acidolysis or glycolysis, in particular by hydrolysis, e.g. as described in the as yet unpublished European

patent applications with file numbers 20192354.7 or 20192364.6. For the purposes of this invention, the term recycling polyol also includes recycling polymer polyol. In principle, a residual content of primary aromatic amines in the resulting polyol is to be expected in all of the recycling processes mentioned for PU foams that were produced with TDI and/or MDI, since these are released in the depolymerization step. The process used for recovery and purification after depolymerization (e.g. removal of aromatic amines and secondary components by distillation) is decisive for the actual content in the respective resulting recycling polyol.

Following the depolymerization process, the recycling polyol can be freed from other recycling products, in particular the primary aromatic amines that also occur and the reagents added for the respective depolymerization process, using conventional separation methods. Some exemplary methods for the purification and recovery of the recycling polyol from the recycling raw product mixture that is present after the respective depolymerization step are mentioned below. One way to separate water from the raw recycle product mixture is to remove it by distillation. 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and / or 4, 4'-diaminodiphenylmethane can by distillation, by extraction with aromatic solvents or by washing with acidic washing water or be removed from the recycling raw product mixture by other methods from the respective recycling polyol, but the complete removal is technically difficult and at high cost. For the purposes of this invention, it is essential in each case that the contents of 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4' -Diaminodiphenylmethane are realized or adjusted, if necessary by the aforementioned purification steps or as shown in the experimental part. Any solid components such as recycling catalysts, salts or Remaining polyurethane components can be separated from the raw product mixture or separated from recycling polyols by filtration with various types of filters.

In particular, the recycling polyol used can be obtained from the hydrolysis of polyurethane, comprising reacting the polyurethane with water in the presence of a base-catalyst combination (I) or (II), where (I) comprises a base having a pKb value of at 25 °C from 1 to 10 °C, and a catalyst selected from the group consisting of quaternary ammonium salts containing an ammonium cation comprising 6 to 30 carbon atoms and organic sulfonates containing at least 7 carbon atoms °C, or wherein (II ) includes a base with a pKb value at 25 ° C of <1, and a catalyst from the group of quaternary ammonium salts containing an ammonium cation with 6 to 14 carbon atoms, provided the ammonium cation does not include a benzyl radical, or containing an ammonium cation having 6 to 12 carbon atoms provided the ammonium cation comprises a benzyl radical. This corresponds to a preferred embodiment of the invention. The use of recycle polyols obtained from the described hydrolysis process, which allows a very simple provision of recycle polyol containing 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4'-diaminodiphenylmethane in the sum of 0.00001% to 0.4% by weight, preferably 0.00002% to 0.2% by weight, particularly preferably 0.00005% to 0.1% % by weight based on the total recycling polyol corresponds to a particularly preferred embodiment of the invention. For the purposes of this invention, it is also essential here that the contents of 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4 '-Diaminodiphenylmethane can be realized or adjusted, if necessary by the above-mentioned purification steps or as shown in the experiment. Corresponding and preferred hydrolysis processes of PU materials are described, for example, in the as yet unpublished European patent applications with file numbers 20192354.7 or 20192364.6.

A particularly preferred variant, referred to here as preferred variant 1, of depolymerization by hydrolysis is described below. In particular, it is preferred if the depolymerization of the polyurethane in step a) using a base with a pKb value at 25 ° C from 1 to 10, preferably 1 to 8, more preferably 1 to 7, in particular 1, 5 to 6, and a catalyst selected from the group consisting of (i) quaternary ammonium salts containing an ammonium cation containing from 6 to 30 carbon atoms and (ii) organic sulfonate containing at least 7 carbon atoms. This corresponds to a preferred embodiment of the invention.

Preferred bases include an alkali metal cation and/or an ammonium cation. Preferred bases here are alkali metal phosphates, alkali metal hydrogen phosphates, alkali metal carbonates, Alkali metal silicates, alkali metal hydrogen carbonates, alkali metal acetates, alkali metal sulphites, ammonium hydroxides or mixtures of the aforementioned. Preferred alkali metals are Na, K or Li or mixtures of the aforementioned, in particular Na or K or mixtures thereof; preferred ammonium cation is NhV.

Particularly preferred bases are K2CO3, Na2SiC>3, NH4OH, K3PO4, or KOAc.

The base is preferably used as a saturated alkaline solution in water, the weight ratio of saturated alkaline solution to PU being in the range of preferably 0.5 to 25, preferably 0.5 to 15, more preferably 1 to 10, in particular 2 to 7. Preferred quaternary ammonium salts have the general structure: R 1 R 2 R 3 R 4 NX with R 1 .R 2 .R 3 , and R 4 are the same or different hydrocarbon groups selected from alkyl, aryl and/or arylalkyl, where R 1 to R 4 are preferably selected such that the sum of the carbon atoms of the quaternary ammonium cation is 6-14, preferably 7-14, more preferably 8-13. X is selected from halide, preferably chloride and/or bromide, hydrogen sulfate,

Alkyl sulfate, preferably methyl sulfate or ethyl sulfate, carbonate, bicarbonate or carboxylate, preferably acetate or hydroxide.

Very particularly preferred quaternary ammonium salts are tributylmethylammonium chloride, tetrabutylammonium hydrogen sulfate, benzyltrimethylammonium chloride, tributylmethylammonium chloride and/or trioctylmethylammonium methyl sulfate.

The organic sulfonate containing at least 7 carbon atoms which can also be used as a catalyst preferably includes alkylaryl sulfonates, alpha-olefin sulfonates, petroleum sulfonates and/or naphthalene sulfonates.

Preferred temperatures for the depolymerization are 80°C to 200°C, preferably 90°C to 180°C, more preferably 95°C to 170°C and in particular 100°C to 160°C.

Preferred reaction times for the depolymerization are 1 minute to 14 hours, preferably 10 minutes to 12 hours, preferably 20 minutes to 11 hours and in particular 30 minutes to 10 hours.

Preference is given to using at least 0.5% by weight of catalyst in the depolymerization, based on the weight of the polyurethane, preferably 0.5 to 15% by weight, more preferably 1 to 10% by weight, even more preferably 1 to 8 % by weight, again more preferably 1 to 7% by weight and in particular 2 to 6% by weight.

A preferred weight ratio of base to polyurethane is in the range from 0.01 to 50, preferably from 0.1 to 25, in particular from 0.5 to 20.

This concerned the preferred variant 1 of the depolymerization. Another particularly preferred variant, referred to here as preferred variant 2, of depolymerization by hydrolysis is described below.

If the depolymerization of the polyurethane in step a) using a base with a pKb value at 25 ° C of <1, preferably 0.5 to -2, preferably 0.25 to -1, 5, in particular 0 to -1, a catalyst from the group of quaternary ammonium salts containing an ammonium cation with 6 to 14 carbon atoms if the ammonium cation does not contain a benzyl radical, or containing an ammonium cation with 6 to 12 carbon atoms if the ammonium cation contains a benzyl radical includes, takes place, there is a further preferred embodiment of the invention.

Preferred bases here are alkali metal hydroxides, alkali metal oxides, alkaline earth metal hydroxides, alkali metal oxides or mixtures thereof. Preferred alkali metals are Na, K or Li or mixtures of the aforementioned, in particular Na or K or mixtures thereof; preferred alkaline earth metals are Be, Mg, Ca, Sr or Ba or mixtures thereof, preferably Mg or Ca or mixtures thereof. A very particularly preferred base is NaOH.

Preferred quaternary ammonium salts have the general structure: R 1 R ₂ R 3 R ₄ NX where R 1 , R 2 , R 3 and R 4 are the same or different hydrocarbyl groups selected from alkyl, aryl and arylalkyl.

X is selected from halide, preferably chloride and/or bromide, bisulfate, alkyl sulfate, preferably methyl sulfate or ethyl sulfate, carbonate, bicarbonate, carboxylate, preferably acetate or hydroxide.

Particularly preferred quaternary ammonium salts here are benzyltrimethylammonium chloride or tributylmethylammonium chloride.

A preferred weight ratio of base to polyurethane is in the range from 0.01 to 25, preferably 0.1 to 15, preferably 0.2 to 10, in particular 0.5 to 5.

An alkaline solution is preferably used, comprising base and water, the concentration of the base preferably being greater than 5% by weight, preferably 5 to 70% by weight, preferably 5 to 60% by weight, more preferably 10 to 50% by weight %, more preferably 15 to 40 % by weight, in particular 20 to 40, based on the weight of the alkaline solution. This concerned the preferred variant 2 of the depolymerization.

The PU to be used in the PU depolymerization process can be any PU product, in particular it comprises a polyurethane foam, preferably PU rigid foam, PU flexible foam, PU hot flexible foam (standard foam), viscoelastic PU foam, HR PU foam, PU -Hypersoft foam, semi-rigid PU foam, thermoformable PU foam and/or integral PU foam.

Recycling polyols which are preferred for the purposes of the invention preferably have a functionality (groups per molecule which are reactive towards isocyanate) of 2 to 8. The recycling polyols preferably contain 2-8 OH groups. The number average molecular weight of the recycle polyol is preferably in the range of 500 to 15000 g/mol. The OH number of the recycling polyols is preferably from 10 to 1200 mg KOH/g. The OH number can be determined in particular on the basis of DIN 53240:1971-12.

A preferred embodiment of the invention is when the recycled polyol employed is structurally a polyether polyol, such recycled polyol preferably being obtainable from the recycling of PU waste, particularly PU foams, originally derived from conventional polyether Polyols or polyether polyols that have already been recycled once or several times were obtained. In their original form, which precedes any recycling, polyether-polyols can be prepared by known processes, e.g. by anionic polymerization of alkylene oxides in the presence of alkali metal hydroxides, alkali metal alcoholates or amines as catalysts and with the addition of at least one starter molecule that preferably contains 2 to 8 reactive hydrogen atoms or by cationic polymerization of alkylene oxides in the presence of Lewis acids such as antimony pentachloride or boron trifluoride etherate or by polymerization of alkylene oxides via double metal cyanide catalysis. Suitable alkylene oxides contain 2 to 4 carbon atoms in the alkylene radical. Examples are tetrahydrofuran, ethylene oxide, 1,3-propylene oxide, 1,2-propylene oxide, 1,2- or 2,3-butylene oxide; ethylene oxide and 1,2-propylene oxide are preferably used. The alkylene oxides can be used individually, cumulatively, in blocks, alternately one after the other, or as mixtures. Dihydric, trihydric or tetrahydric alcohols such as ethylene glycol, 1,2- and 1,3-propanediol, diethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, castor oil, higher polyfunctional polyols, in particular sugar compounds such as glucose, are preferred as starter molecules. Sorbitol, mannitol and sucrose, polyvalent phenols, resols are used.

In a preferred embodiment of the invention, in particular in the production of hot flexible foams, di- or trifunctional polyether polyols can be used Proportion of end groups (PO end groups) arising from propoxylation of preferably over 50%, more preferably over 80%, in particular those with a propylene oxide block or random propylene and ethylene oxide block at the chain end or those based only on propylene oxide blocks. Such polyether polyols preferably have a functionality of 2 to 8, particularly preferably 2 to 4, number-average molecular weights in the range from 500 to 8000, preferably 800 to 5000, particularly preferably 2500 to 4500 g/mol and usually OH numbers in the range of 10 to 100, preferably 20 to 60 mg KOH/g.

According to a preferred embodiment of the invention, in particular for the production of molded and highly elastic flexible PU foams, difunctional and/or trifunctional polyether polyols with preferably at least 50%, more preferably at least 80%, primary hydroxyl groups can be used. In particular, polyether polyols with an ethylene oxide endblock -CH2-CH2-0-H can be used. Polyols for polyurethane cold foams (so-called HR polyols) can be part of this category if the average number-average molar mass simultaneously is preferably above 4000 g/mol.

In a further preferred embodiment of the invention, for the production of PU hypersoft foams, other polyether polyols which consist largely of ethylene oxide, preferably those with ethylene oxide blocks of more than 70%, more preferably of more than 90% ( Hypersoft polyols) can be used. All polyether polyols described in the context of this preferred embodiment preferably have a functionality of 2 to 8 hydroxy groups, preferably 2 to 5 hydroxy groups per molecule, preferably a number average molecular weight of 500 to 8000 g/mol, preferably 800 to 7000 g/mol, and preferably OH numbers in the range from 5 to 100 mg KOH/g, preferably from 20 to 60 mg KOH/g. In the case of hot flexible foams, polyols with primary hydroxyl functions are preferably used not alone, but preferably together with polyols with secondary hydroxyl groups.

In a further preferred embodiment of the invention, particularly in the production of viscoelastic polyurethane foams, preference is given to using mixtures of different, preferably two to three, polyfunctional polyether polyols. The polyol combinations used consist preferably of a crosslinker polyol with a high functionality (>3) and a low molecular weight, preferably with an OH number of 100 to 400 mg KOH/g and/or a conventional flexible block foam polyol and/or or an HR polyol and/or a "hypersoft" polyether polyol, preferably with an OH number between 20 and 40 mg KOH/g with a high proportion of ethylene oxide and cell-opening properties. If HR polyols are used within a viscoelastic foam formulation, their proportion in the polyol mixture is preferably always less than 50%. Regardless of the recycling polyol according to the invention, other polyols can also be used within the scope of the present invention, in particular optional conventional polyols can be used. Conventional polyols are polyols that do not come from recycling processes.

It therefore corresponds to a preferred embodiment of the invention if the total polyol component used comprises both recycling polyol according to the invention and additionally one or more further polyols.

The process according to the invention makes it possible to provide all known types of PU foam. According to a preferred embodiment of the invention, the resulting PU foam is a PU rigid foam, PU flexible foam, a PU hot flexible foam (standard foam), a viscoelastic PU foam, an HR PU foam, a PU hypersoft foam , a semi-rigid PU foam, a thermoformable PU foam or a PU integral foam, preferably a PU hot flexible foam, HR PU foam, PU hypersoft foam or viscoelastic PU foam. PU hot flexible foams are most preferred.

In principle, the PU foams can be produced in the usual manner and as described in the prior art. It is well known to those skilled in the art. A basic overview can be found e.g. B. in G. Oertel, Polyurethane Handbook, 2nd Edition, Hanser/Gardner Publications Inc., Cincinnati, Ohio, 1994, pp. 177-247. Further information on the starting materials, catalysts and auxiliaries and additives that can be used can be found, for example, in the Plastics Handbook, Volume 7, Polyurethane, Carl-Hanser-Verlag Munich, 1st edition 1966, 2nd edition, 1983 and 3rd edition, 1993.

If, in the process according to the invention for the production of PU foams, the reaction is carried out using f) water, g) one or more organic solvents, h) one or more further stabilizers against oxidative degradation, i) one or more flame retardants, and/or j ) one or more other additives, preferably selected from the group of surfactants, biocides, dyes, pigments, fillers, antistatic additives, crosslinkers,

Chain extenders, cell openers, fragrances, cell coarseners, plasticizers, hardeners, aldehyde scavengers, additives for resistance of PU foams to hydrolysis, compatibilizers (emulsifiers), adhesion promoters, hydrophobing additives, flame lamination additives, additives for preventing cold flow, additives to reduce compression set , additives for adjusting the glass transition temperature, temperature-controlling additives and/or odor reducers, a further preferred embodiment of the invention is present.

Another object of the present invention is a composition suitable for the production of polyurethane foam, comprising at least one polyol component, at least at least one isocyanate component, catalyst, foam stabilizer, blowing agent, optional auxiliary, the polyol component being recycling polyol containing 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or or 4,4'-diaminodiphenylmethane, from a total of 0.00001% to 0.4% by weight, preferably 0.00002% to 0.2% by weight, particularly preferably 0.00005% to 0.1% by weight % based on total recycle polyol.

According to a preferred embodiment of the invention, the composition of the invention is characterized in that, based on the total polyol component, more than 30% by weight, preferably more than 50% by weight, preferably more than 70% by weight, more preferably more than 80 wt /or 4,4'-diaminodiphenylmethane, in the sum of 0.00001% to 0.4% by weight, preferably 0.00002% to 0.2% by weight, particularly preferably 0.00005% to 0, 1% by weight based on the total recycled polyol.

The compounds used according to the invention, their production, the use of the compounds for the production of the PU foams and the PU foams themselves are described in more detail below by way of example, without the invention being restricted to these exemplary embodiments. If ranges, general formulas or compound classes are specified below, these should not only include the corresponding ranges or groups of compounds that are explicitly mentioned, but also all sub-ranges and sub-groups of compounds that are obtained by removing individual values (ranges) or compounds can become. If documents are cited in the context of the present description, then their content, in particular with regard to the facts referred to, should fully belong to the disclosure content of the present invention. If percentages are given below, unless otherwise stated, these are percentages by weight. If mean values are given below, they are the numerical mean unless otherwise stated. If the following material properties, such. For example, if viscosities or the like are given, these are the material properties at 25 °C unless otherwise stated. If chemical (sum) formulas are used in the present invention, the indices given can represent both absolute numbers and mean values. In the case of polymeric compounds, the indices preferably represent mean values.

The method according to the invention allows access to all PU foams. Preferred PU foams for the purposes of this invention are flexible PU foams and rigid PU foams. PU flexible foams and PU rigid foams are established technical terms. The well-known and fundamental difference between flexible foams and rigid foams is that flexible foam shows elastic behavior and the deformation is therefore reversible. The hard foam, on the other hand, is permanently deformed. Various subgroups of foams that are preferred within the scope of the invention are described in more detail below, within the scope of this invention, for the sake of simplicity, the term “foam” is used synonymously for that of “foam”.

In the context of the present invention, rigid polyurethane foam is understood to mean, in particular, a foam according to DIN 7726:1982-05, which has a compressive strength according to DIN 53421:1984-06 of advantageously >20 kPa, preferably >80 kPa, preferably >100 kPa, more preferably > 150 kPa, particularly preferably >180 kPa. Furthermore, according to DIN EN ISO 4590:2016-12, the rigid polyurethane foam advantageously has a closed cell content of more than 50%, preferably more than 80% and particularly preferably more than 90%. PU rigid foams are mostly used for insulation purposes. PU flexible foams are elastic, reversibly deformable and usually mostly open cells. This allows the air to escape easily when compressed. The generic term PU flexible foam includes in particular the following types of foam known to those skilled in the art, namely PU hot flexible foam (standard foam), PU cold foam (also highly elastic or high resilience foam), hypersoft PU foam, viscoelastic PU flexible foam and PU ester foams ( from polyester polyols). The different types of flexible PU foam are explained in more detail below and differentiated from one another.

The crucial difference between a PU hot flexible foam and a PU cold flexible foam is the different mechanical properties. The differentiation between PU hot flexible foams and PU cold flexible foams can be made in particular by the rebound elasticity, also known as "ball rebound" (BR) or "resilience". A method for determining the rebound resilience is described, for example, in DIN EN ISO 8307:2008-03. A steel ball with a specified mass is dropped onto the specimen from a certain height and the height of the rebound is then measured as a percentage of the dropping height. PU hot flexible foams have rebound values of preferably 1% to a maximum of 50%. In the case of PU cold flexible foams, the level of rebound is preferably in the range

> 50%. The high rebound resilience of PU cold flexible foams results from a relatively irregular cell size distribution. Another mechanical criterion is the SAG or comfort factor. Here, a foam sample is compressed in accordance with DIN EN ISO 2439:2009-05 and the ratio of the compressive stress at 65% and 25% compression is measured. PU hot flexible foams have a comfort factor of preferably < 2.5. In the case of PU cold flexible foams, the comfort factor is preferably > 2.5. In the production of PU cold flexible foams, polyether polyols which are particularly reactive towards isocyanates and have a high proportion of primary hydroxyl groups and number-average molar masses >4000 g/mol are used. On the other hand, in the case of PU hot flexible foams, predominantly less reactive polyols with secondary OH groups and an average molar mass of <4000 g/mol are usually used. In addition to cold block foams, cold molded foams, which are used e.g. in car seat cushions, represent a core application of PU cold foams.

Also preferred according to the invention are hypersoft PU foams, which represent a subcategory of flexible PU foams. Hypersoft PU foams have compressive stresses determined according to DIN EN ISO 3386-1:1997 + A1:2010 of preferably <2.0 kPa and have an indentation hardness determined according to DIN EN ISO 2439:2009-05 of preferably <80 N. Hypersoft PU foams can be manufactured using a variety of known methods: by using a so-called hypersoft polyol in combination with so-called standard polyols and/or by using a special manufacturing method in which carbon dioxide is metered in during the foaming process. Due to a pronounced open cell structure, Hypersoft PU foams have a high level of air permeability, promote the transport of moisture in application products and help to prevent heat build-up. The Hypersoft polyols used to produce Hypersoft PU foams are characterized in particular by a very high proportion of primary OH groups of more than 60%.

A special class of flexible PU foams is that of viscoelastic PU foams (PU viscose foams), which are likewise preferred according to the invention. These are also known under the name of memory foam and are characterized both by a low rebound resilience according to DIN EN ISO 8307:2008-03 of preferably <15% and by a slow, gradual recovery a completed compression (recovery time preferably 2-13 s). In contrast to hot flexible PU foams and cold flexible PU foams, which have a glass transition temperature of less than -32°C, the glass transition temperature for viscoelastic PU foams is preferably shifted to a range from -20 to +15°C. A pneumatic effect must be distinguished from such "structural viscoelasticity" in open-cell viscoelastic PU foams, which is essentially based on the glass transition temperature of the polymer (also known as chemical viscoelastic foams). In the latter case, there is a relatively closed cell structure (low porosity). Due to the low air permeability, the air only flows back in slowly after compression, which results in a slower recovery (also called pneumatic visco-foams). In many cases, both effects are combined in one visco-foam. PU visco-foams are used because of their energy - and sound-absorbing properties.

A class of PU foams that is particularly important for applications in the automotive sector and that can be classified between those of rigid and flexible foams in terms of properties consists of semi-rigid (semi-flexible) PU foams. These are also preferred according to the invention. Like most PU foam systems, semi-flexible foam systems also use the diisocyanate/water reaction and the resulting CO2 as a foaming agent. The rebound resilience is generally lower than that of classic flexible foams, especially cold foams. Semi-flexible foams are harder than conventional flexible foams. A characteristic feature of semi-flexible foams is their high number of open cells (preferably >90% of the cells). The densities of semi-flexible foams can be significantly higher than those of flexible and rigid foams.

One or more polyols which have two or more OH groups are preferably used as polyol components. The polyol component according to the invention must contain recycled polyol containing 2,4-toluenediamine, 2,6-toluenediamine, 2,2'- Diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4'-diaminodiphenylmethane, totaling 0.00001% to 0.4% by weight, preferably 0.00002% to 0.2% by weight, especially preferably 0.00005% to 0.1% by weight based on total recycle polyol. This has already been described above. In addition, further polyols can optionally be used. Preferred additional polyols that can optionally be used are all of the polyether polyols and polyester polyols customarily used for the production of polyurethane systems, in particular polyurethane foams.

Polyether polyols can, for. B. be obtained by reacting polyhydric alcohols or amines with alkylene oxides. Polyester polyols are preferably based on esters of polybasic carboxylic acids with polyhydric alcohols (mostly glycols). The polybasic carboxylic acids can be either aliphatic (e.g. adipic acid) or aromatic (e.g. phthalic acid or terephthalic acid).

An important class of optionally usable polyols, which is accessible from natural oils such as palm or soybean oil, so-called "natural oil-based polyols" (NOPs) can be obtained on the basis of renewable raw materials. NOPs are of increasing interest for a more sustainable production of PU foams in view of the long-term limited availability of fossil resources, namely oil, coal and gas, and against the background of rising crude oil prices and have already been described many times in the production of polyurethane foams (WO 2005/033167 US 2006/0293400, WO 2006/094227, WO 2004/096882, US 2002/0103091, WO 2006/116456 and EP 1678232). A number of these polyols from various manufacturers are now available on the market (WO 2004/020497, US 2006/0229375, WO 2009/058367). Depending on the basic raw material (e.g. soybean oil, palm oil or castor oil) and the subsequent processing, polyols with different properties result. A distinction can essentially be made here between two groups: a) polyols based on renewable raw materials, which are modified to such an extent that they can be used 100% for the production of polyurethanes (WO2004/020497, US2006/0229375); b) Polyols based on renewable raw materials which, due to their processing and properties, can only replace the petrochemical-based polyol to a certain extent (WO2009/058367). The production of polyurethane foams from recycled polyols together with NOPs represents a preferred application of the invention.

A further class of polyols which can optionally be used are those which are obtained as prepolymers by reacting polyol with isocyanate in a molar ratio of 100:1 to 5:1, preferably 50:1 to 10:1.

The so-called filler polyols (polymer polyols) represent yet another class of optionally usable polyols. These are characterized in that they contain solid organic fillers up to a solids content of 40% by weight or more in disperse distribution. For example, you can use: SAN polyols: These are highly reactive polyols containing a dispersed styrene/acrylonitrile (SAN)-based copolymer.

PHD Polyols: These are highly reactive polyols containing polyurea particles in a dispersed form. PIPA Polyols: These are highly reactive polyols containing polyurethane particles in dispersed form, prepared, for example, by the in situ reaction of an isocyanate with an alkanolamine in a conventional polyol.

The proportion of solids in the optional filler polyols, which depending on the application can preferably be between 5 and >40% by weight, based on the polyol, is responsible for improved cell opening, so that the polyol can be foamed in a controlled manner, especially with TDI, and the foams do not shrink occurs. The solid thus acts as an essential process aid. Another function is to control the hardness via the solids content, since higher solids content causes the foam to be harder.

The formulations with polyols containing solids are significantly less inherently stable and therefore require physical stabilization in addition to chemical stabilization through the crosslinking reaction.

Other polyols that can optionally be used are the so-called cell opener polyols. These are polyether polyols with a high ethylene oxide content, preferably at least 40% by weight, in particular from 50 to 100% by weight, based on the alkylene oxide content. A preferred ratio of isocyanate component to polyol component within the scope of this invention, expressed as an index, is in the range from 10 to 1000, preferably 40 to 350. This index describes the ratio of the amount of isocyanate actually used to the amount of isocyanate theoretically required, corresponding to a stoichiometric ratio of isocyanate - Groups to isocyanate-reactive groups (e.g. OH groups, NH groups), multiplied by 100. An index of 100 represents a molar ratio of the reactive groups of 1 to 1.

One or more isocyanates which have two or more isocyanate functions are preferably used as isocyanate components. All isocyanates, in particular the known aliphatic, cycloaliphatic, araliphatic and preferably aromatic polyfunctional isocyanates, can be used as the isocyanate component in the process according to the invention. Suitable isocyanates for the purposes of this invention have two or more isocyanate functions.

Suitable isocyanates for the purposes of this invention are preferably all polyfunctional organic isocyanates, such as diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HMDI) and isophorone diisocyanate (IPDI). The mixture of MDI and higher-condensed analogues with an average functionality of 2 to 4, known as “polymeric MDI” (“crude MDI” or polyphenylpolymethylene polyisocyanate), can also preferably be used. Particular preference is given to using 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate and/or polyphenylpolymethylene polyisocyanate (crude MDI), 2,4-toluene diisocyanate and/or 2,6-toluene diisocyanate or mixtures of these.

MDI prepolymers are also particularly suitable. Examples of particularly suitable isocyanates are listed, for example, in EP 1712578, EP 1161474, WO 00/58383, US 2007/0072951, EP 1678232 and WO 2005/085310, to which reference is made here in its entirety.

According to a preferred embodiment of the invention, the isocyanates used, preferably diphenylmethane diisocyanate (MDI) and toluene diisocyanate (TDI), preferably consist of at least 20%, more preferably at least 40%, particularly preferably at least 60% recycled isocyanates.

In a preferred embodiment of the invention, the recycling isocyanates from the reaction of aromatic amine mixtures comprising 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4,4' -Diaminodiphenylmethane are prepared, the amine mixtures preferably at least 20%, more preferably at least 35%, particularly preferably at least 50% from the recycling of polyurethanes, preferably polyurethane foams were obtained.

Suitable catalysts which can be used in the process according to the invention for producing PU foam are preferably substances which catalyze the gel reaction (isocyanate-polyol), the blowing reaction (isocyanate-water) or the dimerization or trimerization of the isocyanate. It corresponds to a preferred embodiment of the invention when the catalyst used is selected from

Triethylenediamine, 1,4-diazabicyclo[2.2.2]octane-2-methanol, diethanolamine, N-[2-[2-(dimethylamino)ethoxy]ethyl]-N-methyl-1,3-propanediamine, 2-[[ 2-(2-(dimethylamino)ethoxy)ethyl]methylamino]ethanol, 1,T-[(3-{bis[3-(dimethylamino)propyl]amino}propyl)imino]dipropan-2-ol, [3 -(dimethylamino)propyl]urea, 1,3-bis[3-(dimethylamino)propyl]urea and/or amine catalysts of general structure (1a) and/or structure (1b):

X includes oxygen, nitrogen, hydroxyl, amines of structure (NR ^m or NR ^m R ^lv ) or urea groups (N(R ^V )C(O)N(R ^VI ) or N(R ^V ")C(O)NR ^VI ^RV ")

Y includes amines NR ^VIII R ^IX or ethers OR ^lx R ^UI include identical or different linear or cyclic, aliphatic or aromatic hydrocarbons with 1-8 carbon atoms which are optionally functionalized with an OH group; and/or comprise hydrogen

R ^{III IX} include identical or different linear or cyclic, aliphatic or aromatic hydrocarbons with 1-8 carbon atoms which are optionally functionalized with an OH group, an NH or an NH2 group; and/or comprise hydrogen m = 0 to 4, preferably 2 or 3 n = 2 to 6, preferably 2 or 3 i = 0 to 3, preferably 0-2

R ^x includes identical or different radicals consisting of hydrogen and/or linear, branched or cyclic aliphatic or aromatic hydrocarbons having 1-18 carbon atoms, which can be substituted with 0-1 hydroxyl groups and/or 0-1 NH 2 groups. Z includes oxygen, NR ^x or Ch .

Another class of suitable catalysts, which can preferably be used in the process according to the invention for the production of PU foam, are metal compounds of the metals Sn, Bi, Zn, Al or K, especially Sn, Zn or Bi Subgroups of the organometallic compounds, organometallic salts, organic metal salts and inorganic metal salts, which are explained below.

For the purposes of this invention, the term "organometallic or organometallic compounds" includes, in particular, the use of metal-containing compounds that have a direct carbon-metal bond, here also as organometallic compounds (eg organyl tin) or organometallic or organometallic compounds (eg organotin compounds ) designated. For the purposes of this invention, the term “organometallic or organometallic salts” includes in particular the use of organometallic or organometallic compounds with a salt character, i.e. ionic compounds in which either the anion or cation is of an organometallic nature (e.g. organotin oxides, organotin chlorides or organotin -carboxylates). For the purposes of this invention, the term “organic metal salts” includes, in particular, the use of metal-containing compounds that do not have a direct carbon-metal bond and are also metal salts in which either the anion or the cation is an organic Compound is (e.g. tin(II) carboxylates). In the context of this invention, the expression “inorganic metal salts” includes in particular the use of metal-containing compounds or metal salts in which neither anion nor cation is an organic compound, eg metal chlorides (eg tin(II) chloride). Suitable organic and organometallic metal salts that can be used preferably contain alcoholate, mercaptate or carboxylate anions such as, for example, acetate, 2-ethylhexanoate, octanoate, isononanoate, decanoate, neodecanoate, ricinoleate, laurate and/or oleate, particularly preferably 2-ethylhexanoate, ricinoleate , neodecanoate or isononanoate.

Suitable metal-containing catalysts that can be used are generally preferably selected such that they have no objectionable intrinsic odor, are essentially toxicologically harmless and that the resulting polyurethane systems, in particular polyurethane foams, have the lowest possible catalyst-related emissions.

It may be preferred to combine one or more metal compounds with one or more amine catalysts of formula (1a) and/or (1b). In the production of polyurethane foams according to the present invention, it may be preferred to exclude the use of organometallic salts such as dibutyltin dilaurate.

Suitable amounts of catalysts for the production of PU foam in the process according to the invention depend on the type of catalyst and are preferably in the range from 0.01 to 5 pphp (=parts by weight based on 100 parts by weight polyol) or 0.1 to 10 pphp for potassium salts.

Suitable water contents in the process according to the invention depend on whether or not physical blowing agents are used in addition to the water. In the case of purely water-blown foams, the values are preferably from 1 to 20 pphp, but if other blowing agents are also used, the amount used is usually reduced to, for example, 0 or, for example, 0.1 to 5 pphp. In order to achieve high foam density, preferably neither water nor other blowing agents are used.

Suitable physical blowing agents that can optionally be used in the context of this invention are gases, for example liquefied CO2, and volatile liquids, for example hydrocarbons with 4 or 5 carbon atoms, preferably cyclo-, iso- and n-pentane, fluorocarbons, preferably HFC 245fa, HFC 134a and HFC 365mfc, but also olefinic fluorocarbons such as HHO 1233zd or HH01336mzzZ, chlorofluorocarbons, preferably HCFC 141b, oxygen-containing compounds such as methyl formate and dimethoxymethane, or chlorinated hydrocarbons, preferably dichloromethane and 1,2-dichloroethane. Furthermore, ketones (e.g. acetone) or aldehydes (e.g. methylal) are suitable as blowing agents.

In addition to or instead of water and, if appropriate, physical blowing agents, other chemical blowing agents that react with isocyanates to form gas, such as Formic acid, carbamates or carbonates may be present in the additive composition of the invention.

The substances mentioned in the prior art can be used as foam stabilizers (also called stabilizers for short within the meaning of the invention). Advantageously, the compositions of the invention may contain one or more stabilizers. These are in particular silicon compounds having carbon atoms, preferably selected from the polysiloxanes, polydimethylsiloxanes, organomodified polysiloxanes, polyether-modified polysiloxanes and polyether-polysiloxane copolymers. Preferred silicon compounds are described by formula (1c): Formula (1c): [R ¹ ₂ R ² SiOi/ ₂ ] _a [R ¹ 3SiOi/ ₂ ] [R ¹ ₂ SiO _2/2 ] _c [R ¹ R ² SiO _2/2 ] _d [R ³ Si0 _3/2 ]e [Si0 _4/2 ]f G g with a=0 to 12, preferably 0 to 10, particularly preferably 0 to 8 b=0 to 8, preferably 0 to 6 , particularly preferably 0 to 2 c = 0 to 250, preferably 1 to 200, particularly preferably 1.5 to 150 d = 0 to 40, preferably 0 to 30, particularly preferably 0 to 20 e = 0 to 10, preferably 0 to 8 , particularly preferably 0 to 6 f = 0 to 5, preferably 0 to 3, particularly preferably 0 g = 0 to 3, preferably 0 to 2.5, particularly preferably 0 to 2 where: a+b+c+d+e+f+ g > 3 a + b > 2

G = independently the same or different radicals from (Ol/ ₂ )nSiR ¹ m - CH2CHR ⁵ - R ⁴ - CHR ⁵ CH ₂ - SiR ¹ m(Ol/ ₂ )n (Oi/ ₂ ) _n SiR ¹ m - CH ₂ CHR ⁵ - R ⁴ - CR ⁵ =CH ₂ (Oi/ ₂ ) _n SiR ¹ m - CH ₂ CHR ⁵ - R ⁴ - CR ⁵ =CR ⁵ -CH ₃

R ⁴ = independently the same or different divalent organic radicals, preferably independently the same or different divalent organic radicals of 1 to 50 carbon atoms, optionally interrupted by ether, ester, amide or (-SiR ¹ ₂ 0-) _x SiR ¹ ₂ groups and optionally functionalized with OH groups. More preferably the same or different di-organic radicals of 2 to 30 carbon atoms, optionally interrupted by Ether, ester, amide or (-SiR ¹ ₂ 0-) _x SiR ¹ ₂ groups and optionally functionalized with OH groups x=1 to 50, preferably 1 to 25, particularly preferably 1 to 10

R ⁵ = independently the same or different alkyl radicals consisting of 1 to 16 carbon atoms, aryl radicals having 6 to 16 carbon atoms or hydrogen, preferably from the group of alkyl radicals having 1 to 6 carbon atoms or aryl radicals having 6 to 10 carbon atoms, particularly preferably methyl or hydrogen . where: n = 1 or 2 m = 1 or 2 n + m = 3

R ¹ = identical or different radicals selected from the group of saturated or unsaturated alkyl radicals having 1 to 16 carbon atoms or aryl radicals having 6 to 16 carbon atoms or hydrogen or -OR ⁶ , preferably methyl, ethyl, octyl, phenyl or hydrogen, particularly preferably methyl - or phenyl-

R ² = independently identical or different polyethers obtainable by the polymerization of ethylene oxide and/or propylene oxide and/or other alkylene oxides such as butylene oxide and styrene oxide with the general formula (2) or an organic radical corresponding to the formula (3)

(2) - (R ⁷ ) _h - O - [C ₂ H ₄ 0] i - [CsHeOJj - [CR ⁸ ₂ CR ⁸ ₂ 0] _k - R ⁹

(3) - Oh - R ¹⁰ where h = 0 or 1 R ⁷ = divalent organic radical, preferably divalent organic alkyl or

Aryl radical optionally substituted with -OR ⁶ , more preferably a divalent organic radical of the type CpF p. i = 0 to 150, preferably 1 to 100, particularly preferably 1 to 80 j = 0 to 150, preferably 0 to 100, particularly preferably 0 to 80 k = 0 to 80, preferably 0 to 40, particularly preferably 0 p = 1 bis 18, preferably 1 to 10, particularly preferably 3 or 4 i + j + k > 3

R ³ = identical or different radicals selected from the group of saturated or unsaturated alkyl radicals potentially substituted with heteroatoms, preferably identical or different radicals selected from the group of saturated or unsaturated alkyl radicals having 1 to 16 carbon atoms or aryl radicals having 6 to 16

Carbon atoms potentially substituted with halogen atoms, more preferably methyl, vinyl, chloropropyl or phenyl

R ⁶ = identical or different radicals selected from the group of saturated or unsaturated alkyl radicals having 1 to 16 carbon atoms or aryl radicals having 6 to 16 carbon atoms or hydrogen, preferably saturated or unsaturated alkyl radicals having 1 to 8 carbon atoms or hydrogen, methyl, ethyl, isopropyl or hydrogen.

R ⁸ = identical or different radicals selected from the group of alkyl radicals with 1 to 18 carbon atoms, potentially substituted with ether functions and potentially substituted with heteroatoms such as halogen atoms, aryl radicals with 6 to 18

Carbon atoms potentially substituted with ether functions, or hydrogen, preferably alkyl radicals having 1 to 12 carbon atoms potentially substituted with ether functions and potentially substituted with heteroatoms such as halogen atoms, aryl radicals having 6 to 12 carbon atoms potentially substituted with ether functions, or hydrogen, particularly preferably methyl, ethyl , benzyl or hydrogen.

R ⁹ = same or different radicals selected from the group hydrogen, alkyl, -C(0)-R ¹¹ , -C(0)0-R ¹¹ or -C(0)NHR ¹¹ , saturated or unsaturated, optionally substituted with Heteroatoms, preferably hydrogen or alkyl radicals having 1 to 8 carbon atoms or acetyl, particularly preferably hydrogen, acetyl, methyl or butyl.

R ¹⁰ = identical or different radicals selected from the group of saturated or unsaturated alkyl radicals or aryl radicals potentially substituted with OH, ether, epoxide, ester, amine and/or halogen substituents, preferably saturated or unsaturated alkyl radicals having 1 to 18 carbon atoms or aryl radicals 6 - 18 carbon atoms optionally substituted with OH, ether, epoxide, ester, amine and/or halogen substituents, particularly preferably saturated or unsaturated alkyl radicals having 1 to 18 carbon atoms or aryl radicals having 6 to 18 carbon atoms substituted with at least one OH, ether, Epoxy, ester, amine and/or halogen substituents. R ¹¹ = identical or different radicals selected from the group of saturated or unsaturated alkyl radicals having 1 to 16 carbon atoms or aryl radicals having 6 to 16 carbon atoms, preferably saturated or unsaturated alkyl radicals having 1 to 8 Carbon atoms or aryl radicals having 6 to 16 carbon atoms, particularly preferably methyl, ethyl, butyl or phenyl

The foam stabilizers of the formula (1c) can be used in PU systems, preferably mixed in organic solvents such as, for example, dipropylene glycol, polyether alcohols or polyether diols. In the case of mixtures of stabilizers of the formula (1c), a compatibilizer can preferably also be used. This can be selected from the group of aliphatic or aromatic hydrocarbons, particularly preferably aliphatic polyethers or polyesters. The substances mentioned in the prior art can preferably be used as silicon compounds having one or more carbon atoms. Those Si compounds which are particularly suitable for the particular type of foam are preferably used. Suitable siloxanes are described, for example, in the following documents: EP 0839852, EP 1544235, DE 102004001408, WO 2005/118668, US 2007/0072951, DE 2533074, EP 1537159 EP 533202, US 3933695, EP 0724239, DE 0724239, DE 429044 867465. The manufacture of the Si

Connections can be made as described in the prior art. Suitable examples are e.g. e.g. in US 4147847, EP 0493836 and US 4855379.

Preferably, from 0.00001 to 20 parts by mass of foam stabilizers, in particular silicon compounds, can be used per 100 parts by mass of polyol components. All substances known from the prior art which are used in the production of polyurethanes, in particular polyurethane foams, can be used as further optional additives, such as blowing agents, preferably water to form CO 2 and, if necessary, other physical blowing agents Flame retardants, buffer substances, surfactants, biocides, dyes, pigments, fillers, antistatic additives, crosslinkers, chain extenders, cell openers as described, for example, in EP 2998333A1, nucleating agents, thickeners, fragrances, cell coarseners as described, for example, in EP 2986661 B1, plasticizers, hardeners/additives for preventing cold flow, as described, for example, in DE 2507161C3, WO 2017029054A1, aldehyde scavengers, as described, for example, in WO 2021/013607A1, additives for resistance of PU foams to hydrolysis, as described, for example, in US 2015/0148438A1, compatibilizers (emulsifiers), adhesion promoters , hydrophobing additives, Flam lamination additives as described, for example, in EP 2292677B1, compression set-reducing additives, odor reducers, additives for adjusting the glass transition temperature, temperature-controlling additives and/or additional catalytically active substances, in particular as defined above. Crosslinkers that can be used as an option and chain extenders that can be used as an option are low molecular weight, polyfunctional compounds that are reactive toward isocyanates. Suitable substances are, for example, hydroxyl- or amine-terminated substances such as glycerol, neopentyl glycol, 2-methyl-1,3-propanediol, dipropylene glycol, triethanolamine (TEOA), diethanolamine (DEOA) and trimethylolpropane and sugar compounds. Crosslinkers that can also be used are polyethoxylated and/or polypropoxylated glycerol or sugar compounds, provided their number-average molecular weight is below 1500 g/mol. The optional use concentration is preferably between 0.1 and 5 parts, based on 100 parts of polyol, but can also deviate from this depending on the formulation. When using crude MDI for foam molding, this also takes on a crosslinking function. The content of low-molecular crosslinkers can therefore be correspondingly reduced as the amount of crude MDI increases.

Suitable optional additional stabilizers against oxidative degradation are preferably all common free-radical scavengers, peroxide scavengers, UV absorbers, light stabilizers, complexing agents for metal ion impurities (metal deactivators). Compounds which can preferably be used are the following substance classes or substance classes containing the following functional groups: 2-hydroxybenzophenones, benzoic acids and benzoates, phenols, in particular containing tert-butyl and/or methyl substituents on the aromatic compound, benzofuranones, diarylamines, triazines, 2,2,6,6-tetramethylpiperidines , hydroxylamines, alkyl and aryl phosphites, sulfides, zinc carboxylates, diketones.

Suitable optional flame retardants for the purposes of this invention are all substances which are considered suitable according to the prior art. Preferred flame retardants are, for example, liquid organic phosphorus compounds, such as halogen-free organic phosphates, e.g. triethyl phosphate (TEP), halogenated phosphates, e.g. tris(1-chloro-2-propyl) phosphate (TCPP), tris(1,3-dichloroisopropyl) phosphate ( TDCPP) and tris(2-chloroethyl) phosphate (TCEP) and organic phosphonates, e.g. dimethyl methane phosphonate (DMMP), dimethyl propane phosphonate (DMPP), or oligomers ethyl ethylene phosphates or solids such as ammonium polyphosphate (APP) and red phosphorus. Halogenated compounds, for example halogenated polyols, and solids such as expandable graphite and melamine are also suitable as flame retardants.

The process according to the invention makes it possible to produce polyurethane foams with particularly high proportions of recycling polyols. For the purposes of the invention, the term polyurethane is to be understood in particular as a generic term for a polymer made from di- or polyisocyanates and polyols or other species that are reactive towards isocyanate, such as amines, for example, where the urethane bond does not have to be the exclusive or predominant type of bond. Polyisocyanurates and polyureas are also expressly included.

The production of polyurethane foams according to the invention can be carried out by any method familiar to the person skilled in the art, for example by hand mixing or preferably with the aid of high-pressure or low-pressure foaming machines. The process according to the invention can be carried out continuously or batchwise. A discontinuous implementation of the method is preferred in the production of molded foams, refrigerators, shoe soles or panels. A continuous procedure is preferred in the production of insulating panels, metal composite elements, blocks or spray processes. Another object of the present invention is a polyurethane foam, preferably PU rigid foam, PU flexible foam, PU hot flexible foam (standard foam), viscoelastic PU foam, HR PU foam, PU hypersoft foam, semi-rigid PU foam, thermoformable PU foam or PU integral foam, preferably PU hot flexible foam, HR PU foam, PU hypersoft foam or viscoelastic PU foam, produced according to an inventive

Procedure as previously described. Flexible PU foams are most preferred.

A very particularly preferred flexible polyurethane foam for the purposes of this invention has the following composition in particular:

Component Parts by weight (pphp) Polyol comprising Recycled Polyol 100 of the invention

(amine) catalyst 0.01 to 5

Tin catalyst 0 to 5, preferably 0.001 to 2

Siloxane 0.1 to 15, preferably 0.2 to 7

Water 0 to <15, preferably 0.1 to 10 Other blowing agents 0 to 130

Flame retardants 0 to 70 fillers 0 to 150 other additives 0 to 20

Isocyanate index: greater than 50 The polyurethane foams according to the invention can, for. B. as refrigerator insulation, insulating board, sandwich element, pipe insulation, spray foam, 1 & 1.5 component can foam (a 1.5 component can foam is a foam that is produced by destroying a container in the can), imitation wood, model foam , packaging foam, mattress, furniture pad, automotive seat pad, headrest, instrument panel, automotive interior trim, automotive headliner, sound absorbing material, steering wheel, shoe sole, carpet backing foam, filter foam, sealing foam, sealant, adhesive, binder, paint or as a coating or to manufacture related products be used. This corresponds to a further object of the invention.

The present invention is described by way of example in the examples listed below, without the invention, the scope of which results from the entire description and the claims, being restricted to the embodiments mentioned in the examples. examples

Production and characterization of the recycling polyols

Determination of toluenediamine (TDA) in recycling polyols Unless otherwise stated, all percentages (%) given are percentages by mass.

In the context of the present invention, the mass fraction of toluenediamine from the sum of the 2,4- and the 2,6-isomer is determined by means of HPLC.

For this purpose, 25 mg of the polyol according to the invention are dissolved in 25 ml of a solution consisting of an aqueous 20 mM diammonium hydrogen phosphate solution and acetonitrile (70:30). An aliquot of the solution is analyzed by HPLC. The analysis is carried out with an HPLC system equipped as follows:

Instrument: LC Agilent 1260 Column: Phenomenex Luna C18(2), 250mm x 4.6mm, 5.0pm

Oven temperature: 40°C

Eluent: A: 20 mM (NH ₄ ) ₂ HRO ₄ B: acetonitrile

Injection volume: 25 pL Detector: DAD 220nm

Flow: 1mL/min

Gradient:

Analysis time: 25 min

2,4- and 2,6-toluenediamine are separated based on their different polarity.

For the evaluation, an external calibration is carried out with standard solutions of 2,4- and 2,6-toluenediamine and a calibration curve is created. The concentration of the analytes in the sample is then determined by evaluating the peak areas. The statement of the mass fraction of the sum of 2,4- and 2,6-diaminotoluene is given in % by weight based on the total mass of the recycling polyol in question. Determination of diaminodiphenylmethane (MDA) in recycling polyols

All percentages (%) given are percentages by mass unless otherwise stated.

The mass fraction of diaminodiphenylamine (sum of the isomers 2,4'-MDA, 2,2'-MDA, 4,4'-MDA) is determined in the context of the present invention by means of HPLC.

Instrument: LC Agilent 1260

Column: Phenomenex Luna C18(2), 250mm x 4.6mm, 5.0pm

Oven temperature: 40°C Eluent: A: 20 mM (NH ₄ ) ₂ HR0 ₄ B: acetonitrile

Injection volume: 25 pL

Detector: DAD 220nm

Flow: 1 mL/min Gradient:

Analysis time: 25 min

Diaminodiphenylamine (methylenediphenyldiamine) is separated from the matrix due to the different polarity.

For the evaluation, an external calibration is carried out with standard solutions of methylenediphenyldiamine and a calibration line is created. The concentration of the analyte in the sample is then determined by evaluating the peak areas. The mass fraction of MDA (total of the isomers) is stated in % by weight based on the total mass of the recycling polyol in question. Recvclinq-Polvol 1 (according to the invention)

The recycled Pqlyql 1 according to the invention was obtained by the hydrolysis of polyurethane in the presence of a saturated K ₂ CO 3 solution and tetrabutylammonium hydrogen sulfate as catalyst: A Parr reactor (Parr Instrumental Company) equipped with a PTFE inner vessel and a mechanical stirrer was used filled with 25 g compressed foam pieces (approx. 1 cm x 1 cm). The polyurethane foam used was prepared according to Formulation 1 using the conventional polycarbonate Arccl® 1104. Then 75 g of saturated K ₂ CC>3 solution (pKb value 3.67 at 25 °C) were added. The catalyst tetrabutylammonium hydrogen sulfate was then added at 5% by weight based on the mass of the reaction mixture. The reactor was sealed and the reaction mixture was heated to an internal temperature of 150°C for 14 hours. Upon completion of the 14 hours, heating was discontinued and the reaction mixture was cooled to room temperature. After opening the reactor, the reaction mixture was transferred to a round bottom flask. The water was removed via rotary evaporation and the remaining reaction mixture was extracted with cyclohexane. The cyclohexane solution was washed with 1N aqueous HCl solution and then dried over magnesium sulfate. After removing cyclohexane via rotary evaporation, recycle polyol 1 with a content of 0.0389% by weight of toluenediamine (TDA, sum of the 2,4- and the 2,6-isomer) was obtained. The hydrolysis process was repeatedly applied to produce a large enough amount of recycled polyol for the

to provide foaming experiments.

Recvclinq-Polvol 2 (according to the invention)

The recycling polyol 2 according to the invention was obtained by the hydrolysis of polyurethane in the presence of a 30% sodium silicate solution and tributylmethylammonium chloride as a catalyst:

A Parr reactor (Parr Instrumental Company) equipped with a PTFE inner vessel and a mechanical stirrer was charged with 25 g of compressed foam pieces (ca. 1 cm×1 cm). The polyurethane foam used was prepared according to Formulation 1 in which the conventional polyol Arcol® 1104 was used. Then 75 g of sodium silicate solution (30% by weight in water) were added.

The catalyst tributylmethylammonium chloride was then added at 2.5% by weight based on the mass of the reaction mixture. The reactor was sealed and the reaction mixture was heated to an internal temperature of 150°C for 10 hours. Upon completion of the 10 hours, heating was discontinued and the reaction mixture was cooled to room temperature. After opening the reactor, the reaction mixture was transferred to a round bottom flask. The water was removed via rotary evaporation and the remaining reaction mixture was extracted with cyclohexane. The cyclohexane phase was washed with 1N aqueous HCl solution and then dried over magnesium sulfate. After Removal of cyclohexane via rotary evaporation gave recycling polyol 2 with a proportion of 0.1220% by weight of toluenediamine (TDA, sum of the 2,4 and the 2,6 isomer). The hydrolysis process was repeated to provide a sufficient amount of recycled polyol for the foaming experiments.

Recvclinq-Polvol 3 (not according to the invention)

The non-inventive recycling polyol 3 (prior art) was obtained by the hydrolysis of polyurethane in the presence of a 20% by weight NaOH solution and tetrabutylammonium hydrogen sulfate as a catalyst:

A Parr reactor (Parr Instrumental Company) equipped with a PTFE inner vessel and a mechanical stirrer was charged with 25 g of compressed foam pieces (ca. 1 cm×1 cm). The polyurethane foam used was prepared according to Formulation 1 in which the conventional polyol Arcol® 1104 was used. Then 75 g of sodium hydroxide solution (20% by weight in water) were added. The catalyst tetrabutylammonium hydrogen sulfate was then added at 5% by weight, based on the mass of the reaction mixture. The reactor was sealed and the reaction mixture was heated to an internal temperature of 130°C for 14 hours. Upon completion of the 14 hours, heating was discontinued and the reaction mixture was cooled to room temperature. After opening the reactor, the reaction mixture was transferred to a round bottom flask. The water was removed via rotary evaporation and the remaining reaction mixture was extracted with cyclohexane. The cyclohexane solution was washed with a little 1N aqueous HCl solution and then dried over magnesium sulfate. After removing cyclohexane via rotary evaporation, recycle polyol 3 with a content of 0.7260% by weight of toluenediamine (TDA, sum of the 2,4- and the 2,6-isomer) was obtained. The hydrolysis process was repeated to provide a large enough amount of recycled polyol for the foaming experiments.

Recvclinq-Polvol 4 (according to the invention)

The recycling Pqlyql 4 according to the invention was obtained by the hydrolysis of polyurethane in the presence of a 20% sodium hydroxide solution and tributylmethylammonium chloride as catalyst:

A Parr reactor (Parr Instrumental Company) equipped with a PTFE inner container and a mechanical stirrer was charged with 25 g of compressed foam pieces (ca. 1 cm×1 cm). The polyurethane foam used was prepared according to Formulation 1 using the conventional polycarbonate Arccl® 1104. Then 75 g of sodium hydroxide solution (20% by weight in water) were added.

The catalyst tributylmethylammonium chloride was then added at 2.5% by weight based on the mass of the reaction mixture. The reactor was sealed and that The reaction mixture was heated to an internal temperature of 130°C for 14 hours. Upon completion of the 14 hours, heating was discontinued and the reaction mixture was cooled to room temperature. After opening the reactor, the reaction mixture was transferred to a round bottom flask. The water was removed via rotary evaporation and the remaining reaction mixture was extracted with cyclohexane. The cyclohexane phase was washed with 1N aqueous HCl solution and then dried over magnesium sulfate. After removing the cyclohexane via rotary evaporation, the recycling polyol 4 containing 0.0002% by weight of toluenediamine (TDA, sum of the 2,4- and the 2,6-isomer) was obtained and used for foaming experiments. The hydrolysis process was repeated to provide a large enough amount of recycled polyol for the foaming experiments.

Production of PU flexible foams

The following formulation was used to produce hot flexible foam for testing the recycling polyols with regard to their foaming properties and their influence on the physical foam properties. In this context, for example, 1.0 part (1.0 pphp) of a component means 1 g of this substance per 100 g of polyol.

Table 1: Formulation for the production of PU hot-cure flexible foams.

Formulation 1 Parts by mass (pphp) Polyol ¹⁾ 100 pphp

Water 4.00 pphp

KOSMOS® T9 ²⁾ 0.20 pphp DABCO ^® DMEA ³⁾ 0.15 pphp TEGOSTAB ^® BF2370 ⁴⁾ 1.0 pphp Desmodur ^® T 80 ⁵⁾ Variable, constant index of 105

¹⁾ Polyol: standard polyether polyol Arcol® 1104 available from Covestro, this is a glycerol-based polyether polyol with an OH number of 56 mg KOH/g and an average molar mass of 3000 g/mol or recycling according to the invention Polyols or recycled polyol not according to the invention. The recycled polyols are processed via a chemical

Recycling process made from PU hot flexible foams. The respective recycling processes for producing the recycling polyols according to the invention and those not according to the invention are described above.

²⁾ KOSMOS® T9, available from Evonik Industries: tin(II) salt of 2-ethylhexanoic acid. ³⁾ DABCO® DMEA: dimethylethanolamine, available from Evonik Industries. Amine catalyst for the production of polyurethane foams

⁴⁾ Polyether modified polysiloxane available from Evonik Industries.

⁵⁾ Toluene diisocyanate T 80 (80% 2,4-isomer, 20% 2,6-isomer) from Covestro, 3 mPa·s, 48% NCO, functionality 2.

General procedure for the production of PU hot flexible foams

The polyurethane foams were produced in the laboratory as so-called hand foams. The foams were produced according to the following information at 22° C. and 762 mm Hg air pressure. To produce the polyurethane foams according to formulation 1, 150 g and 300 g of polyol were used in each case. The other formulation components were converted accordingly. For example, 1.0 part (1.0 pphp) of a component meant 1 g of this substance per 100 g of polyol.

For the foams according to formulation I, the tin catalyst tin(II) 2-ethylhexanoate, polyol, the water, the amine catalysts and the respective foam stabilizer were placed in a paper cup and mixed for 60 s with a disc stirrer at 1000 rpm. After the first stirring, the isocyanate was added and mixed in with the same stirrer for 7 s at 2500 rpm and immediately poured into a paper-lined box (for foams made from 300 g polyol: 30 cm ^x 30 cm base area and 30 cm height, for Foams of 150 g polyol: 18 cm ^x 18 cm base area and 18 cm height). After pouring, the foam rose in the foaming box. Ideally, the foam blew off when the maximum rise height was reached and then sagged back slightly. The cell membranes of the foam bubbles opened up and an open-pored cell structure of the foam was obtained.

The characteristic parameters described in the following section were determined to assess the properties.

Characterization of the manufactured PU foams

The foams produced were evaluated on the basis of the following physical properties: a) Sagging of the foam after the end of the rise phase (=fall back).

The relapse or subsequent ascent results from the difference in foam height after direct blowing off and after 3 minutes after blowing off the foam. The foam height is measured using a needle attached to a centimeter ruler at the maximum in the center of the foam dome. A positive value describes the sagging of the foam after blowing off, a negative value describes the subsequent rise of the foam. b) Foam height is the height of the free-rising foam formed after 3 minutes. Foam height is reported in centimeters (cm). c) rise time

The time between the end of mixing the reaction components and the blowing off of the polyurethane foam. The rise time is given in seconds (s). d) porosity

The air permeability of the foam was determined based on DIN EN ISO 4638:1993-07 by measuring the dynamic pressure on the foam. The back pressure measured was given in mm of water column, with the lower back pressure values then characterizing the more open foam. The values were measured in the range from 0 to 300 mm water column. The dynamic pressure was measured using an apparatus comprising a nitrogen source, reducing valve with manometer, flow control screw, washing bottle, flow meter, T-piece, support nozzle and a scaled glass tube filled with water. The support nozzle has an edge length of 100×100 mm, a weight of 800 g, a clear width of the outlet opening of 5 mm, a clear width of the lower support ring of 20 mm and an outer diameter of the lower support ring of 30 mm.

The measurement is carried out by setting the nitrogen pre-pressure to 1 bar using the reducing valve and adjusting the flow rate to 480 l/h. The amount of water is set in the graduated glass tube in such a way that no pressure difference can be built up and read. To measure the test specimen with dimensions of 250 x 250 x 50 mm for foams made from 300 g polyol or 150 x 150 x 50 mm for foams made from 150 g polyol, the contact nozzle is placed on the corners of the test specimen with the edges congruent and once on the ( estimated) center of the test specimen (each on the side with the largest surface). It is read when a constant back pressure has been established. The evaluation is carried out by averaging over the five measured values obtained. d) Number of cells per cm (cell number): This is determined optically on a cut surface (measured according to DIN EN 15702:2009-04). f) Compression hardness CLD 40% according to DIN EN ISO 3386-1:1997 + A1:2010. The measured values are given in kilopascals (kPa). g) compression set

Five specimens each measuring 5 cm×5 cm×2.5 cm were cut out of the finished foams. The initial thickness was measured. The compression set was measured at the earliest 72 hours after manufacture in accordance with DIN EN ISO 1856:2018-11. The specimens were placed between the plates of the former and were compressed to 90% of their thickness (ie to 2.5mm). Within 15 minutes the specimens were placed in an oven at 70°C and left there for 22 hours. After this time, the device was taken out of the oven, the specimens were removed from the device within 1 minute and placed on a wooden surface. After 30 minutes relaxation, the thickness was measured again and the compression set calculated. The results are given in percent according to the following formula: DVR=(d0-dr)/d0 x 100% h) Tensile strength and elongation at break according to DIN EN ISO 1798:2008-04. The measured values for tensile strength are given in kilopascals (kPa), for elongation at break in percent (%). i) Resilience according to DIN EN ISO 8307:2008-03. The measurement values are given in percent (%). j) Emissions of the PU foams determined according to the VDA 278 measuring principle

The materials are characterized with regard to the type and quantity of the organic substances that can be outgassed from them. For this purpose, two semi-quantitative cumulative values are determined, which enable the emission of volatile organic compounds (VOC value) and the proportion of condensable substances (fog value) to be estimated. Furthermore, individual substances of the emission are determined. During the analysis, the samples are extracted thermally, the emissions are separated by gas chromatography and detected by mass spectrometry. The total concentrations thus obtained for the VOC portion are calculated in toluene equivalents and give the VOC value as the result, the FOG portion is presented in hexadecane equivalents and gives the FOG value.

The analysis method is used to determine emissions from non-metallic materials that are used for molded parts in motor vehicles, including foams.

In thermal desorption analysis (TDS), small amounts of material are heated up in a desorption tube in a defined manner, and the volatile substances emitted are cryofocused with the aid of a stream of inert gas in a cold trap of a temperature-programmable evaporator. After the heating phase has ended, the cold trap is quickly heated to 280 °C. In the process, the focused substances evaporate. They are then separated in the gas chromatographic separation column and detected by mass spectrometry. By calibrating with reference substances, a semi-quantitative estimation of the emission, expressed in "pg/g", is possible. Toluene for the VOC analysis (VOC value) and n-hexadecane for the fog value are used as quantitative reference substances. Signal peaks can be assigned to substances on the basis of their mass spectra and retention indices. Source: VDA 278/10.2011, www.vda.de

analytics

Specimens: Sample preparation, sampling and specimen dimensions

After the PU foams have been produced, they are stored for 24 hours at 21 °C and approx. 50% relative humidity. Test specimens are then distributed evenly across the width of the PU specimen taken from suitable and representative locations. The foams are then wrapped in aluminum foil and sealed in a polyethylene bag.

The amount of foam samples introduced into the desorption tube is 10-15 mg each. Conducting the test: VOC/FOG thermal desorption

Immediately after receipt of the sealed test specimens, they are sent for direct determination. Before the start of the analysis, the samples are weighed on the analytical balance to within 0.1 mg and the corresponding amount of foam is placed in the middle of the desorption tube. A stream of helium is passed over the sample and it is heated to 90 °C for 30 minutes. All volatile substances are trapped in a cold trap cooled with liquid nitrogen. After 30 minutes, the cold trap is heated to 280 °C. The evaporating substances are separated from one another using the gas chromatographic column described and then analyzed by mass spectroscopy.

Device parameters GC-MS The following device is used for the analysis:

Gerstel

D-45473 Mühlheim an der Ruhr,

Eberhard-Gerstel-Platz 1 TDS-3 / KAS-4 Tenax® desorption tubes Agilent Technologies 7890A (GC) / 5975C (MS)

Column: HP Ultra2 (50m, 0.32mm, 0.52pm)

Carrier gas: helium

Table 2: Foaming results for the PU hot flexible foams produced according to formulation 1, Table 1 with 150 g polyol using recycling polyols 1, 2 and 3 and the conventional polyol Arcol® 1104.

‘Total VOC values and fog values of the isomers 2,4-toluenediamine and 2,6-toluenediamine.

The results in Table 2 compare the foaming of the recycling polyols 1, 2 according to the invention and the recycling polyol 3 not according to the invention with Arcol® 1104. The three recycling polyols 1, 2 and 3 were all made from polyurethane foams, which originally consisted of Arcol® 1104 were produced, so that Arcol® 1104 is the originating polyol and as

reference is used. The comparison of the properties of foams #1, #2 and #3 shows that comparable foams to reference foam #1 from Arcol® 1104 are obtained with the recycling polyols 1 and 2 according to the invention. Only the height of rise for #2 and #3 is slightly below that of reference foam #1. The use of the non-inventive recycling polyol 3 leads to the collapse of the foam. Surprisingly, the same TDA emissions (sum of the VOC values and fog values for 2,4- and 2,6-toluenediamine) of <5 pg based on 1 g PU- Foam measured according to VDA 278. Table 3: Foaming results for the PU hot flexible foams, produced according to formulation 1, Table 1, each with 300 g polyol component using the recycling polyols 2 and 4 and the conventional polyol Arcol® 1104 The results in Table 3 compare the foaming of the recycling polyols 2 and 4 according to the invention. The comparison of the properties of foams #5 and #6 shows that with the recycling polyols 4 according to the invention a foam comparable to reference foam #5 from Arcol® 1104 is obtained will. The use of 70 pphp of Recycled Polyol 2 together with 30 pphp of the reference polyol Arcol® 1104 allows the production of Foam #7 with properties essentially the same as Foams #5 and #6.

Claims

Expectations

1. A method for producing PU foams by reacting (a) at least one polyol component, comprising recycling polyol, with

(b) at least one isocyanate component in the presence of

(c) one or more catalysts which catalyze the isocyanate-polyol and/or isocyanate-water reactions and/or the isocyanate trimerization, (d) at least one foam stabilizer and

(E) optionally one or more chemical or physical blowing agents, characterized in that the recycling polyol used is 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or Contains 4,4'-diaminodiphenylmethane, in a total amount of 0.00001% to 0.4% by weight, preferably 0.00002% to 0.2% by weight, particularly preferably 0.00005% to 0. 1% by weight based on total recycle polyol.

2. The method according to claim 1, characterized in that the PU foam is a PU rigid foam, a PU flexible foam, a PU hot flexible foam, a viscoelastic PU foam, a HR PU foam, a PU hypersoft Foam, a semi-rigid PU foam, a thermoformable PU foam or a PU integral foam, preferably a PU hot flexible foam, HR PU foam, PU hypersoft foam or viscoelastic PU foam, with PU hot flexible foams being most preferred are.

3. The method according to at least one of claims 1 or 2, characterized in that the reaction is carried out using f) water, g) one or more organic solvents, h) one or more stabilizers against oxidative degradation, in particular antioxidants, i) a or more flame retardants, and / or j) one or more other additives, preferably selected from the group of surfactants, biocides, dyes, pigments, fillers, antistatic additives, crosslinkers, chain extenders, cell openers, fragrances, cell coarsening agents, plasticizers, hardeners, aldehyde scavengers , additives for resistance of PU foams to hydrolysis, compatibilizer (emulsifier), adhesion promoter, hydrophobing additives, flame lamination additives, cold flow prevention additives, compression set reducing additives, and/or odor modifiers.

4. The method according to at least one of claims 1 to 3, characterized in that the foam stabilizer is selected from the group of silicon compounds containing carbon atoms, which are preferably described by the formula (1c), or mixtures of several of these compounds:

Formula (1c): [R ¹ ₂ R ² SiOi/ ₂ ]a [R ¹ 3SiOi/ ₂ ] [R ¹ ₂ Si0 ₂₂ ] _c [R ¹ R ² Si0 ₂₂ ] _d [R ³ Si0 _3/2 ]e [Si0 _4/2 ] _f G _g with a = 0 to 12, preferably 0 to 10, particularly preferably 0 to 8 b = 0 to 8, preferably 0 to 6, particularly preferably 0 to 2 c = 0 to 250, preferably 1 to 200, particularly preferably 1.5 to 150 d=0 to 40, preferably 0 to 30, particularly preferably 0 to 20 e=0 to 10, preferably 0 to 8, particularly preferably 0 to 6 f=0 to 5, preferably 0 to 3, particularly preferably 0 g = 0 to 3, preferably 0 to 2.5, particularly preferably 0 to 2 where: a + b + c + d + e + f + g > 3 a + b > 2

G = independently the same or different radicals from (Oi/ ₂ ) _n SiR ¹ m - CH ₂ CHR ⁵ - R ⁴ - CHR ⁵ CH ₂ - SiR ¹ _m (Oi/ ₂ ) _n (Oi/ ₂ ) _n SiR ¹ m - CH ₂ CHR ⁵ - R ⁴ - CR ⁵ =CH ₂ (Oi/ ₂ ) _n SiR ¹ m - CH ₂ CHR ⁵ - R ⁴ - CR ⁵ =CR ⁵ -CH ₃

R ⁴ = independently the same or different divalent organic radicals, preferably independently the same or different divalent organic radicals of 1 to 50 carbon atoms, optionally interrupted by ether, ester, amide or (-SiR ¹ ₂ 0-) _x SiR ¹ ₂ groups and optionally functionalized with OH groups. Particularly preferably the same or different double organic radicals of 2 to 30 carbon atoms, optionally interrupted by ether, ester, amide or (-SiR ¹ ₂ 0-) _x SiR ¹ ₂ groups and optionally functionalized with OH groups x = 1 to 50, preferably 1 to 25, particularly preferably 1 to 10 R ⁵ = independently the same or different alkyl radicals consisting of 1 to 16 carbon atoms, aryl radicals having 6 to 16 carbon atoms or hydrogen, preferably from the group of alkyl radicals having 1 to 6 carbon atoms or aryl radicals having 6 to 10 carbon atoms, particularly preferably methyl or hydrogen . where: n = 1 or 2 m = 1 or 2 n + m = 3

(3) - Oh - R ¹⁰ where h = 0 or 1

R ⁷ = divalent organic radical, preferably divalent organic alkyl or aryl radical optionally substituted with -OR ⁶ , particularly preferably a divalent organic radical of the type C _P H _2p . i = 0 to 150, preferably 1 to 100, particularly preferably 1 to 80 j = 0 to 150, preferably 0 to 100, particularly preferably 0 to 80 k = 0 to 80, preferably 0 to 40, particularly preferably 0 p = 1 bis 18, preferably 1 to 10, more preferably 3 or 4 where i + j + k > 3

R ³ = identical or different radicals selected from the group of saturated or unsaturated alkyl radicals potentially substituted with heteroatoms, preferably identical or various radicals selected from the group of saturated or unsaturated alkyl radicals having 1 to 16 carbon atoms or aryl radicals having 6 to 16 carbon atoms potentially substituted with halogen atoms, particularly preferably methyl, vinyl, chloropropyl or phenyl

R ⁸ = identical or different radicals selected from the group of alkyl radicals having 1 to 18 carbon atoms, potentially substituted with ether functions and potentially substituted with heteroatoms such as halogen atoms, aryl radicals having 6 to 18 carbon atoms, potentially substituted with ether functions, or hydrogen, preferably alkyl radicals with 1 to 12 carbon atoms potentially substituted with ether functions and potentially substituted with heteroatoms such as halogen atoms, aryl radicals having 6 to 12 carbon atoms potentially substituted with ether functions, or hydrogen, more preferably methyl, ethyl, benzyl or hydrogen.

R ¹⁰ = identical or different radicals selected from the group of saturated or unsaturated alkyl radicals or aryl radicals potentially substituted with OH, ether, epoxide, ester, amine and/or halogen substituents, preferably saturated or unsaturated alkyl radicals having 1 to 18 carbon atoms or aryl radicals 6 - 18 carbon atoms optionally substituted with OH, ether, epoxide, ester, amine and/or halogen substituents, particularly preferably saturated or unsaturated alkyl radicals having 1 to 18 carbon atoms or aryl radicals having 6 to 18 carbon atoms substituted with at least one OH, ether, Epoxy, ester, amine and/or halogen substituents.

R ¹¹ = identical or different radicals selected from the group of saturated or unsaturated alkyl radicals having 1 to 16 carbon atoms or aryl radicals having 6 to 16 carbon atoms, preferably saturated or unsaturated alkyl radicals having 1 to 8 carbon atoms or aryl radicals having 6 to 16 carbon atoms, particularly preferably methyl -, ethyl, butyl or phenyl

5. The method according to at least one of claims 1 to 4, characterized in that the catalyst for the production of PU foam is selected from

Triethylenediamine, 1,4-diazabicyclo[2.2.2]octane-2-methanol, diethanolamine, N-[2-[2-(dimethylamino)ethoxy]ethyl]-N-methyl-1,3-propanediamine, 2-[[ 2-(2-

(dimethylamino)ethoxy)ethyl]methylamino]ethanol, 1,1'-[(3-{bis[3-(dimethylamino)propyl]amino}propyl)imino]dipropan-2-ol, [3-(dimethylamino)propyl ]urea, 1,3-bis[3-(dimethylamino)propyl]urea and/or amine catalysts of the general structure (1a) and/or the structure (1b):

Y includes amines NR ^VIII R ^IX or ethers OR ^lx R ^UI include identical or different linear or cyclic, aliphatic or aromatic hydrocarbons having 1-8 carbon atoms which are optionally functionalized with an OH group; and/or comprise hydrogen

R ^{III IX} include identical or different linear or cyclic, aliphatic or aromatic hydrocarbons with 1-8 carbon atoms which are optionally functionalized with an OH group, an NH or an NH2 group; and/or comprise hydrogen m = 0 to 4, preferably 2 or 3 n = 2 to 6, preferably 2 or 3 i = 0 to 3, preferably 0 to 2 R ^x includes identical or different radicals consisting of hydrogen and/or linear, branched or cyclic aliphatic or aromatic hydrocarbons with 1-18 carbon atoms, which can be substituted with 0-1 hydroxyl groups and 0-1 NH 2 groups.

Z includes oxygen, ^NRx or CH2. and or

Metal compounds including organometallic metal salts, organic metal salts, inorganic metal salts and organometallic compounds (and mixtures of these compounds) of the metals Sn, Bi, Zn, Al or K, especially Sn or Bi.

6. The method according to at least one of claims 1 to 5, characterized in that, based on the total polyol component used, more than 30% by weight, preferably more than 50% by weight, preferably more than 70% by weight, more preferably more than 80% by weight, in particular more than 95% by weight, recycling polyol is used, the recycling polyol being 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2, 4'-diaminodiphenylmethane and/or 4,4'-diaminodiphenylmethane in a total amount of 0.00001% to 0.4% by weight, preferably 0.00002% to 0.2% by weight, particularly preferred 0.00005% to 0.1% by weight based on total recycle polyol.

7. The method according to at least one of claims 1 to 6, characterized in that the recycling polyol used was obtained from the hydrolysis of polyurethane, comprising reacting the polyurethane with water in the presence of a base-catalyst combination (I) or

(II), wherein (I) comprises a base having a pKb value at 25°C of 1 to 10, and a catalyst selected from the group consisting of quaternary ammonium salts containing an ammonium cation comprising 6 to 30 carbon atoms and organic Sulfonates containing at least 7 carbon atoms is chosen, or where (II) comprises a base with a pKb value at 25 ° C of <1, and a catalyst from the group of quaternary ammonium salts containing an ammonium cation with 6 to 14 carbon atoms, provided that the ammonium cation does not comprise a benzyl radical, or containing an ammonium cation having 6 to 12 carbon atoms, provided that the ammonium cation comprises a benzyl radical.

8. Composition suitable for producing polyurethane foam, comprising at least one polyol component containing recycled polyol, at least one isocyanate component, catalyst, foam stabilizer, blowing agent, optionally auxiliaries such as surfactants, biocides, dyes, pigments, fillers, antistatic additives , Crosslinkers, chain extenders, cell openers and/or fragrances, characterized in that the recycling polyol used contains 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane and/or 4 , 4'- Diaminodiphenylmethane contains, in a total amount of 0.00001% to 0.4% by weight, preferably 0.00002% to 0.2% by weight, particularly preferably 0.00005% to 0.1% by weight , based on total recycled polyol.

9. Polyurethane foam, preferably PU rigid foam, PU flexible foam, PU hot flexible foam, viscoelastic PU foam, HR PU foam, PU hypersoft foam, semi-rigid PU foam, thermoformable PU foam or PU integral foam, preferably PU -Hot flexible foam, HR PU foam, PU hypersoft foam or viscoelastic PU foam, most preferably PU hot flexible foam, characterized in that it is obtained by a process according to at least one of claims 1 to 7.

10. Use of PU foams according to claim 9 as refrigerator insulation, insulating board,

Sandwich element, pipe insulation, spray foam, 1- & 1.5-component canned foam, imitation wood, model foam, packaging foam, mattress, furniture upholstery, automotive seat upholstery, headrest, instrument panel, automotive interior trim, automotive headliner, sound absorption material, steering wheel, shoe sole, carpet backing foam , filter foam, sealing foam, sealant and adhesive, coating or to manufacture related products.