Reduced-emission polyurethane foam

Abstract

The present invention relates to a isocyanate-reactive component, to a method for producing a polyurethane foam using the isocyanate-reactive component, to the polyurethane foam and to a use of the isocyanate-reactive component for producing the polyurethane foam.

Description

[0001] POLYURETHANE FOAM WITH REDUCED EMISSIONS

[0002] The present invention relates to a component which is reactive towards isocyanates, a polyurethane foam obtainable therefrom with low aldehyde emission and / or low odor, a process for producing the polyurethane foam with the aid of the component which is reactive towards isocyanates and the use thereof for producing a polyurethane foam with low aldehyde emission and / or low odor.

[0003] Polyurethane foams have been known as versatile materials for many years. Their use in automotive construction and automotive interiors is also state-of-the-art.

[0004] The undesirable emission of aldehyde compounds, such as formaldehyde or acetaldehyde, as well as the undesirable emission of compounds that humans perceive as having a bad smell, is problematic. Various approaches have been presented to reduce the emission of aldehyde compounds and / or reduce the odor of polyurethane foams.

[0005] EP 2762510 A1 discloses the use of polyurea and / or polyhydrazocarbonamide particles in a polyol component for the production of low-emission polyurethane foams. In particular, larger amounts of polyurea dispersion are used in a polyol component that also contains polyols with a functionality of three or higher.

[0006] US 2013 / 0203880 A1 discloses the use of polyhydrazodicarbonamide dispersion polyols in relatively small amounts to reduce aldehyde emissions.

[0007] A common feature of the prior art is the use of medium-functional polyols, i.e., in the range of 3.0 to 4.0, in combination with polyurea dispersion (PHD) polyols in isocyanate-reactive components that also include stabilizers. These stabilizers are the amphiphilic compounds familiar to those skilled in the art, whose purpose is to prevent collapse of the foam being produced.

[0008] The object of the present invention was to provide a component which is reactive towards isocyanates and whose reaction with an isocyanate composition in a process for producing a polyurethane foam results in a polyurethane foam which at least partially overcomes the problems described in the prior art, in particular a polyurethane foam with reduced aldehyde emissions and / or reduced odor.

[0009] In particular, reduced aldehyde emissions within the meaning of this invention mean that the emission of formaldehyde and / or acetaldehyde is reduced. Reduced aldehyde emissions within the meaning of this invention preferably mean that the emission of formaldehyde, determined according to VDA275: 1994-07, is <0.75 mg / kg foam, preferably <0.70 mg / kg foam, particularly preferably <0.65 mg / kg foam, or that the emission of acetaldehyde, determined according to VDA275: 1994-07, is <0.15 mg / kg foam, preferably <0.10 mg / kg foam. Particularly preferably, reduced aldehyde emission in the sense of this invention means that the emission value pairs of formaldehyde and acetaldehyde, each determined according to VDA275: 1994-07, are below the stated limit values, i.e. for formaldehyde / acetaldehyde in mg / kg foam: <0.75 / 0.15, <0.75 / 0.10, 0.70 / 0.15, <0.70 / 0.10, <0.65 / 0.15, 0.65 / 0.1.Furthermore, reduced odor within the meaning of this application means in particular that the polyurethane foam has an odor rating, determined according to VDA270; C3, of <3.5, preferably <3.0.

[0010] The problem was surprisingly solved by a component reactive towards isocyanates comprising a polyol composition A comprising

[0011] A1. A polyether polyol with a functionality f < 2.8, A2. A polyether polyol with a functionality f > 4.0, and A3. A filled polyol, a catalyst C, a blowing agent D, optionally further isocyanate-reactive, low-molecular-weight compounds E that do not fall under polyol composition A, and optionally auxiliaries and / or additives F, wherein the isocyanate-reactive component contains essentially no stabilizer or no stabilizer at all.

[0012] Thus, an isocyanate-reactive component comprising a polyol composition A, i.e. a mixture of at least three polyols A1, A2 and A3, is provided, which are a polyether polyol with a functionality of at most 2.8 (polyether polyol A1), a polyether polyol with a functionality of at least 4.0 (polyether polyol A2) and a filled polyol (polyol A3).

[0013] Polyether polyols are generally known from the prior art. They are obtainable, for example, by polyaddition of alkylene oxides to polyfunctional starter substances in the presence of catalysts. The poly(oxyalkylene) polyols used according to the invention are prepared from a starter compound or a starter compound mixture with an average of < 2.8 active hydrogen atoms, for example, hydroxyl groups, in the case of Al or > 4.0 active hydrogen atoms, for example, hydroxyl groups, in the case of A2, and in each case one or more alkylene oxides.

[0014] Preferred starter compounds for Al are molecules with 2 to 8 hydroxyl groups per molecule, with starter compounds with 2 hydroxyl groups being particularly preferred. Examples of such difunctional starter compounds for Al are ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,4-butenediol, 1,4-butynediol, neopentyl glycol, 1,5-pentanediol, methylpentanediols (such as 3-methyl-1,5-pentanediol), 1,6-hexanediol; 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, bis-(hydroxymethyl)-cyclohexanes (such as 1,4-bis-(hydroxymethyl)cyclohexane), triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, tripropylene glycol, polypropylene glycols, dibutylene glycol and polybutylene glycols), or mixtures of two or more of the aforementioned compounds, most preferably 1,2-propylene glycol is used.Particularly preferably, the starter compound consists of one or more of these difunctional compounds, for example 1,2-propylene glycol.

[0015] The polyether polyols A1 and A2 used according to the invention are prepared from one or more alkylene oxides. Preferred alkylene oxides are ethylene oxide, propylene oxide, and butylene oxide. These can be used alone or in a mixture. When used in a mixture, it is possible to react the alkylene oxides randomly or blockwise, or both alternately.

[0016] The polyether polyol A1 preferably has an OH number of <56 mg KOH / g or a number-average molecular weight of >2000 g / mol. The polyether polyol A1 particularly preferably has an OH number of <56 mg KOH / g and a number-average molecular weight of >2000 g / mol.

[0017] Further preferably, the polyether polyol A1 has an OH number of <40 mg KOH / g, for example 10 - 40 mg KOH / g or 20 - 40 mg KOH / g, or a number-average molecular weight of 2000 - 6000 g / mol, for example 2500 - 5500 g / mol or 3000 - 5000 g / mol. Particularly preferably, the polyether polyol Al has an OH number of <40 mg KOH / g and a number-average molecular weight of 2000 - 6000 g / mol, for example 10 - 40 mg KOH / g and 2500 - 5500 g / mol, 10 - 40 mg KOH / g and 3000 - 5000 g / mol, 20 - 40 mg KOH / g and 2500 - 5500 g / mol or 20 - 40 mg KOH / g and 3000 - 5000 g / mol.

[0018] The OH number (also known as "hydroxyl number") indicates, in the case of a single polyol, the amount of potassium hydroxide in milligrams equivalent to the amount of acetic acid bound during the acetylation of one gram of substance. It is determined in the context of this invention according to DIN 53240-2, as of November 2007. OH number values ​​for mixtures refer to the number-average OH number of the mixture, calculated from the OH numbers of the individual components in their respective molar proportions.

[0019] Furthermore, the functionality of the polyether polyol AI is preferably f < 2.6, more preferably f < 2.5, f < 2.4, even more preferably f < 2.3, most preferably f < 2.2.

[0020] The "functionality" or "f" within the meaning of this application is the theoretical functionality, based on the number of active hydrogens in the starter substances from which polyols such as polyether or polyester polyols are prepared. Thus, for each individual polyol, the theoretical functionality is an integer. Mixtures of such polyols, for example, polyols produced from a mixture of di- or trifunctional starter substances, may have a theoretical functionality that lies between the functionalities of the starter substances. For example, a mixture of polyols prepared from an equimolar mixture of ethylene glycol and glycerol has a theoretical functionality of 2.5.

[0021] In the context of the present invention, the number-average molecular weight Mw is calculated from the OH number determined experimentally as described using the formula Mw = 56106 f / OH number, whereby the number-average molecular weight in g / mol is obtained when the numerical value of the OH number in mg KOH / g is inserted.

[0022] In one embodiment, the polyether polyol Al has a proportion of primary OH functions, based on the total number of terminal OH functions in Al, of 70 - 90%, preferably of 72 - 88%, more preferably of 75 - 85%.

[0023] In a preferred embodiment, the proportion of the polyether polyol A1, based on the total amount of the polyol composition A, is 60 - 90 wt.%, more preferably 65 - 85 wt.%.

[0024] The polyol A2 according to the invention is also a polyether polyol, for which the basic statements as for Al regarding production etc. apply.

[0025] Preferred starter compounds for A2 are molecules with 2 to 8, especially 3 to 8, hydroxyl groups per molecule, such as triethanolamine, glycerol, trimethylolpropane, pentaerythritol, sorbitol, sucrose, or mixtures of two or more of the aforementioned compounds. Particular preference is given to molecules with 4 to 8 hydroxyl groups per molecule, particularly preferred are pentaerythritol, sorbitol, sucrose, or mixtures of two or three of the aforementioned compounds, most preferred being sorbitol. The starter substances can be used alone or in a mixture with lower-functionality, including difunctional starter substances such as diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, 1,4-butanediol, and 1,6-hexanediol. In a preferred embodiment, the polyether polyol A2 has an OH number of <100 mg KOH / g, preferably <80 mg KOH / g, more preferably <60 mg KOH / g, most preferably 15 - 40 mg KOH / g.It may also have a number-average molecular weight of 6000-15000 g / mol, preferably 8000-14000 g / mol. In particular, the polyether polyol A2 may have a number-average molecular weight of 6000-15000 g / mol and an OH number of <100 mg KOH / g, preferably <80 mg KOH / g, more preferably <60 mg KOH / g, most preferably 15-40 mg KOH / g; or it may have a number-average molecular weight of 8000-14000 g / mol and an OH number of <100 mg KOH / g, preferably <80 mg KOH / g, more preferably <60 mg KOH / g, most preferably 15-40 mg KOH / g.

[0026] In a further preferred embodiment, the polyether polyol A2 has a proportion of primary OH functions, based on the total number of terminal OH functions in A2, of 75 - 95%, preferably of 80 - 90%.

[0027] In a preferred embodiment, the proportion of polyether polyol A2, based on the total amount of polyol composition A, is 5.0 - 40.0 wt.%, preferably 10.0 - 30.0 wt.%, more preferably 12.0 - 28.0 wt.%, particularly preferably 15.0 - 25.0 wt.%.

[0028] Polyol A3 is a precipitated polyol. Such filled polyols are generally known in the art. They are typically polyether polyols that are "filled" with other organic polymers to produce viscous, white to off-white liquids. Precipitated polyols are generally produced by in-situ polymerization, either by free-radical or stepwise addition, of one or more monomers in a base polyol. Common filled polyols include styrene-acrylonitrile polymer polyols (i.e., SAN polymer polyols), polyurea dispersion polyols (i.e., PHD polyols), and polyisocyanate polyaddition polyols (i.e., PIPA polyols).

[0029] A PHD polyol contains a dispersion of a polyurea in a base polyol formed in situ by polymerizing a diamine or hydrazine and an isocyanate, while a PIPA (polyisocyanate polyaddition) polyol contains a polymer dispersion formed by reacting an alkanolamine with an isocyanate. Theoretically, any base polyol known in the art can be suitable for preparing polymer polyol dispersions; however, polyether polyols are preferred as the base polyol in the present invention, particularly polyether polyols prepared using ethylene oxide and / or propylene oxide, which are reacted with an at least bifunctional alcohol, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, dibutylene glycol, glycerol, or trimethylolpropane.Particularly preferred are base polyols obtainable from the reaction of ethylene oxide and / or propylene oxide with glycerol, most preferably those obtainable from the reaction of ethylene oxide and propylene oxide with glycerol.

[0030] Amines suitable for the preparation of PHD polyols include polyamines, hydrazine, hydrazide, ammonia, and mixtures of urea and formaldehyde.

[0031] Suitable polyamines include, but are not limited to, primary and / or secondary aliphatic amines, alicyclic amines and aromatic amines, e.g. ethylenediamine, 1,2-propanediamine and 1,3-propanediamine, tetramethylenediamine, hexamethylenediamine, dodecamethylenediamine, trimethyldiaminohexane, N,N'-dimethylethylenediamine, 2,2'-bis-aminopropylmethylamine, higher valent diamine derivatives such as diethylenetriamine, triethylenetetramine, tetraethylpentaamine, dipropyltriamine, piperazine, N,N'-bis-aminoethylpiperazine, triazine, 4-aminobenzenamine, 4-aminophenylethylamine, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-Diaminodicyclohexylpropane, 1,4-Diaminocyclohexane, phenylenediamine, naphthalenediamine, condensation products of aniline and formaldehyde, toluenediamine, diaminomethylbenzene and monoalkylated derivatives of aromatic diamines.The polyamine generally has a molecular weight of 60 - 10000 g / mol, preferably 60 - 1000 g / mol, most preferably 60 - 200 g / mol.

[0032] Suitable hydrazines include hydrazine itself, monosubstituted, or N,N'-disubstituted hydrazine. The substituent can be a C1-C6 alkyl group, a cyclohexyl group, or a phenyl group. The molecular weight of the hydrazines is typically 32-200 g / mol. Suitable hydrazides include hydrazides of dibasic or higher carboxylic acids, including, for example, carbonic acid, oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, and terephthalic acid. Hydrazine monocarboxylic acid and dihydric alcohol or esters of polyols and phenols such as ethylene glycol, 1,2-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, and hydroquinone; amides (semicarbazides) of hydrazinecarboxylic acid, such as diamines and polyamines as described above.The hydrazides typically have a molecular weight of 90 - 10000 g / mol, preferably 90 - 1000 g / mol, particularly preferably 90 - 500 g / mol.

[0033] Isocyanates, amines, hydrazines, or hydrazides with a functionality of more than 2 can also be used, especially when used in combination with corresponding monofunctional compounds. In one embodiment, the PHD polyol can have a propylene oxide and / or ethylene oxide cap. The ethylene oxide content can be 10-25%, preferably 13-22%, based on the total amount of alkylene oxide in the PHD polyol.

[0034] The precipitated polyol A3 is preferably a polyol, in particular a polyurea dispersion polyol, having a number-average molecular weight of 4000 - 8000 g / mol, preferably 5000 - 7000 g / mol, and / or an OH number of 10 - 50 mg KOH / g, preferably 15 - 40 mg KOH / g, more preferably 20 - 35 mg KOH / g.

[0035] The precipitated polyol A3 is preferably a polyol, in particular a polyurea dispersion polyol, having a functionality of 2.0 - 4.0, more preferably from 2.2 to 3.8, even more preferably from 2.5 to 3.5.

[0036] Further preferably, the proportion of the filled polyol A3, in particular a polyurea dispersion polyol, based on the total amount of the polyol composition A, is at least 1.0 wt.%, preferably 1.0-30.0 wt.%, more preferably 1.0-20.0 wt.%, even more preferably 1.0-10.0 wt.%, further more preferably 1.0-5.0 wt.%, most preferably 1.5-3.0 wt.%.

[0037] More preferably, the polyol composition A comprises at most 24.0 wt.%, preferably at most 16.0 wt.%, particularly preferably at most 8.0 wt.%, more preferably at most 4.0 wt.%, most preferably at most 2.4 wt.%, based on the total amount of the polyol composition A, of polyether polyols having a functionality of 2.9 to 3.9.

[0038] In a preferred embodiment, the polyol composition comprises at most 8.0 wt.%, at most 5.0 wt.%, at most 3.0 wt.%, or at most 2.0 wt.%, based in each case on the total amount of the polyol composition, of a vegetable oil-based polyol. For the purposes of this application, a vegetable oil-based polyol is a polyol produced using an unsaturated fatty acid and glycerol or a lipid that can be obtained by extraction from fruits, seeds, or embryos of plants.

[0039] In principle, all chemical and physical blowing agents known from the prior art for the production of polyurethane foams can be used as blowing agents, in particular water. Instead of or in addition to water, other blowing agents can be used, e.g., liquid carbon dioxide, hydrocarbons such as cyclopentane or pentane, partially fluorinated or perfluorinated alkenes, partially chlorinated and fluorinated alkenes, formic acid, or mixtures thereof. Water is preferably used, particularly preferably in an amount, based on the total amount of the polyol composition, of 1.0 to 5.0 wt. %, more preferably of 1.2 to 4.0 wt. %, even more preferably of 1.5 to 3.5 wt. %, particularly preferably of 2.0-3.2 wt. %.

[0040] In principle, all catalysts known from the state of the art for the production of polyurethane foams are suitable as catalysts, especially those suitable for accelerating the reaction of the isocyanate composition with water and / or isocyanate-reactive compounds. Examples of such compounds include organic metal compounds and amines.

[0041] Examples of suitable, catalytically active metal compounds are tin(II) salts of carboxylic acids with 2-24 carbon atoms such as tin(II) 2-ethylhexanoate, tin(II) 2-butyloctoate or tin(II) ricinoleate as well as organotin(IV) compounds such as dibutyltin(IV) dilaurate or dimethyltin(IV) neodecanoate.

[0042] Both incorporable and non-incorporable amines can be used as amine catalysts. An incorporable amine is a compound that contains at least one amino group and at least one isocyanate-reactive group, where the amino group can be the at least one isocyanate-reactive group. A non-incorporable amine is a compound that contains at least one amino group and no isocyanate-reactive group.

[0043] Suitable non-incorporable amines are, for example, the tertiary amines triethylamine, tributylamine, dimethylcyclohexylamine, dimethylbenzylamine, N-methylimidazole, N-methyl-,N-ethyl-,N-cyclohexylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-

[0044] Tetramethylbutylenediamine, N,N,N',N'-tetramethylhexylenediamine-1,6,

[0045] Pentamethyldiethylentriamin, Tetramethyldiaminoethylether, Bis-(dimethylaminopropy 1 )- hamstoff, Dimethylpiperazin, 1,2-Dimethylimidazol, I-Aza-bicyclo-[3,3,0]-octan, 1,4-Diaza- bicyclo-[2,2,2]-octan.Suitable amines that can be incorporated are, for example, N(3-dimethylaminopropyl)-N,N-diisopropanolamine, 6-dimethylaminohexanol, N-[2-[2-(dimethylamino)ethoxy]ethyl]-N-methyl-1,3-propanediamine, N,N-dimethylaminopropylamine, bis(dimethylaminopropyl)amine, N,N-dimethylaminopropyl-N'-methyl-ethanolamine, dimethylaminoethoxyethanol, bis-(dimethylaminopropyl)amino-2-propanol, N,N-dimethylaminopropyldipropanolamine, N,N,N'-trimethyl-N'-hydroxyethyl bisaminoethyl ether, N,N-dimethylaminopropyl urea, N-(2-hydroxypropyl)-imidazole, N-(2-Hydroxyethyl)-imidazole, N-(2-Aminopropyl)-imidazole, 2-((Dimethylamino)ethyl)methylaminopropanol, l,l'-((3-(Dimethylamino)propyl)imino)bis-2-propanol and / or reaction products of ethyl acetoacetate, polyether polyols and 1-(dimethylamino)-3-aminopropane and in particular the tallolic acid amide salt of N,N-dimethylaminopropylamine.Furthermore, low-molecular-weight compounds with molecular weights of less than 400 g / mol, in particular di- or trifunctional amines and alcohols, or generally polyamines, polyamino alcohols, or polythiols, as well as mixtures of two or more of the aforementioned, for example diethyltoluenediamine, can also be used as further isocyanate-reactive compounds in the isocyanate-reactive component according to the invention. Di- or polyhydric alcohols are considered polyol composition A in the context of this invention, while those compounds that carry at most one hydroxyl group are considered low-molecular-weight compounds E, which are not included in polyol composition A.

[0046] It is also possible to use auxiliaries or additives known from the state of the art, for example surface-active substances, stabilizers, fillers, dyes, pigments, flame retardants such as melamine, expandable graphite or aluminum hydroxide, antistatic agents, hydrolysis protection agents and / or fibrostatic and bacteriostatic substances.

[0047] The invention is further directed to a process for producing a polyurethane foam comprising

[0048] Reaction of the isocyanate-reactive component according to the invention and an isocyanate composition B comprising a di- or polyisocyanate to obtain the polyurethane foam.

[0049] Suitable isocyanate compositions include isocyanates with an NCO functionality of > 2. Examples of such polyisocyanates are 1,4-butylene diisocyanate, 1,5-pentane diisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,2,4- and / or 2,4,4-trimethylhexamethylene diisocyanate, the isomeric bis(isocyanatocyclohexyl)methanes or mixtures thereof of any isomer content, 1,4-cyclohexylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), 1,5-naphthylene diisocyanate, 2,2'- and / or 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI) and / or higher homologues, 1,3- and / or 1,4-bis-(2-isocyanato-prop-2-yl)-benzene (TMXDI), l,3-bis-(isocyanatomethyl)benzene (XDI), and alkyl-2,6-diisocyanatohexanoates (lysine diisocyanates) with CI to C6 alkyl groups.

[0050] Polyisocyanates that can be used include mixtures of the isomers of diphenylmethane diisocyanate (“monomeric MDI”, abbreviated “mMDI”), i.e., 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 2,2'-diphenylmethane diisocyanate, and its oligomers (“oligomeric MDI”). Mixtures of monomeric MDI and oligomeric MDI are generally referred to as “polymeric MDI” (pMDI). The oligomers of MDI are higher-nuclear polyphenylpolymethylene polyisocyanates, i.e., mixtures of the higher-nuclear homologues of diphenylmethylene diisocyanate, which have an NCO functionality > 2 and the following molecular formula: C15H10N2O2 [CsHsNO]n, where n = an integer > 0.

[0051] In addition to the polyisocyanates mentioned above, modified diisocyanates with uretdione, isocyanurate, urethane, carbodiimide, uretonimine, allophanate, biuret, amide, iminooxadiazinedione and / or oxadiazinetrione structure can also be used proportionally.

[0052] Instead of or in addition to the above-mentioned polyisocyanates, suitable NCO prepolymers can also be used as polyisocyanates in the isocyanate composition. The prepolymers can be prepared by reacting one or more polyisocyanates with one or more polyols, preferably by reacting one of the above-mentioned polyisocyanates, particularly preferably by reacting MDI or pMDI with a polyol.

[0053] In the process according to the invention, preference is given to using an NCO prepolymer obtainable from the reaction of MDI with a polyol. Particular preference is given to reacting MDI with a carbohydrate-initiated polyol, in particular with a polyol having a functionality of >4.5, preferably with a polyol having a functionality of >5.0 or >5.5, very particularly preferably with a sorbitol-initiated polyether polyol. Furthermore, the polyol reacted with MDI preferably has an OH number of <112 mg KOH / g, particularly preferably <56 mg KOH / g, more preferably <40 mg KOH / g, most preferably 16-40 mg KOH / g or 20-40 mg KOH / g. In addition, a preferred NCO prepolymer has a content of monomeric MDI, based on the total amount of the NCO prepolymer, of 40 - 80 wt.%, in particular 45 - 75 wt.%, most preferably 48 - 70 wt.%.

[0054] The isocyanate composition is preferably used in an amount such that an index (also "isocyanate index," "index," or "isocyanate index") in the range from 95 to 115, particularly preferably 100 to 110, very particularly preferably 103 to 108 results. For the purposes of this application, the index describes the ratio of all reactive hydrogen atoms of the isocyanate-reactive compounds to the number of NCO groups in the isocyanate composition, multiplied by 100. An index of 100 represents an equimolar ratio (1:1) of reactive hydrogen atoms to NCO groups. An index greater than 100 represents an excess of NCO groups, and an index less than 100 represents a deficiency of NCO groups.

[0055] The invention is also directed to a polyurethane foam obtainable by the process according to the invention. Such a polyurethane foam has low aldehyde emissions and / or a low odor. The polyurethane foam according to the invention therefore preferably has a formaldehyde emission, determined according to VDA275: 1994-07, of <0.75 mg / kg foam, preferably <0.70 mg / kg foam, particularly preferably <0.65 mg / kg foam, and / or an acetaldehyde emission, determined according to VDA275: 1994-07, of <0.15 mg / kg foam, preferably <0.10 mg / kg foam, and / or an odor rating, determined according to VDA270; C3, of <3.5, preferably <3.0. Very particularly preferably, a polyurethane foam according to the invention has both the acetaldehyde and formaldehyde emissions described in this paragraph and the odor described in this paragraph.

[0056] The invention also relates to the use of the isocyanate-reactive component according to the invention for producing a polyurethane foam with low aldehyde emissions and / or low odor. In particular, the isocyanate-reactive component according to the invention can be used to produce a polyurethane foam having a formaldehyde emission, determined according to VDA275: 1994-07, of <0.75 mg / kg foam, preferably <0.70 mg / kg foam, particularly preferably <0.65 mg / kg foam, and / or an acetaldehyde emission, determined according to VDA275: 1994-07, of <0.15 mg / kg foam, preferably <0.10 mg / kg foam, and / or an odor rating, determined according to VDA270; C3, of <3.5, preferably <3.0.Very particular preference is given to using the isocyanate-reactive component according to the invention for producing a polyurethane foam which has both the acetic and formaldehyde emissions described in this paragraph and the odor described in this paragraph.

[0057] Finally, the invention is directed to a polyurethane reaction mixture comprising the isocyanate-reactive component of the invention and an isocyanate composition comprising a di- or polyisocyanate. Particularly preferably, the polyurethane reaction mixture consists of the isocyanate-reactive component of the invention and an isocyanate composition comprising a di- or polyisocyanate. These individual constituents of the polyurethane reaction mixture preferably have the preferred properties and / or components described above.

[0058] Particularly preferably, the polyurethane reaction mixture according to the invention comprises at most 24.0 wt.%, preferably at most 16.0 wt.%, particularly preferably at most 8.0 wt.%, more preferably at most 4.0 wt.%, most preferably at most 2.4 wt.%, based on the total amount of the polyol composition A, of polyether polyols having a functionality of 2.9 to 3.9.

[0059] The invention is also described in more detail by the following sentences.

[0060] Sentence 1 : Isocyanate-reactive component comprising a polyol composition A comprising

[0061] Al. a polyether polyol with a functionality f < 2.8,

[0062] A2. a polyether polyol with a functionality f > 4.0, and

[0063] A3, a precipitated polyol, a catalyst C, a blowing agent D, optionally further isocyanate-reactive, low-molecular compounds E which do not fall under the polyol composition A, and optionally auxiliaries and / or additives F, wherein the isocyanate-reactive component contains essentially no stabilizer or no stabilizer at all.

[0064] Sentence 2: Isocyanate-reactive component according to sentence 1, wherein the polyether polyol Al has an OH number, determined according to DIN 53240-2, as of November 2007, of < 56 mg KOH / g.

[0065] Sentence 3: Isocyanate-reactive component according to one of sentences 1 or 2, wherein polyether polyol Al has a number-average molecular weight of > 2000 g / mol.

[0066] Sentence 4: Isocyanate-reactive component according to one of sentences 1 to 3, wherein in the polyether polyol Al the proportion of primary OH functions, based on the total number of terminal OH functions in Al, is 70 - 90%, preferably 75 - 85%.

[0067] Sentence 5: Isocyanate-reactive component according to one of sentences 1 to 4, wherein the polyether polyol A2 has an OH number, determined according to DIN 53240-2, as of November 2007, of <100 mg KOH / g, preferably <80 mg KOH / g, more preferably <60 mg KOH / g, most preferably 15 - 40 mg KOH / g.

[0068] Sentence 6: Isocyanate-reactive component according to one of sentences 1 to 5, wherein the polyether polyol A2 has a number-average molecular weight of 6000 - 15000 g / mol, preferably 8000 - 13000 g / mol.

[0069] Sentence 7: Isocyanate-reactive component according to any one of sentences 1 to 6, wherein the proportion of primary OH functions in polyether polyol A2, based on the total number of terminal OH functions in A2, is 75-95%, preferably 80-90%. Sentence 8: Isocyanate-reactive component according to any one of sentences 1 to 7, wherein the polyether polyol A2 has an OH number, determined according to DIN 53240-2, as of November 2007, of <100 mg KOH / g, preferably <80 mg KOH / g, more preferably <60 mg KOH / g, most preferably 15-40 mg KOH / g.

[0070] Sentence 9: Isocyanate-reactive component according to one of sentences 1 to 8, wherein the filled polyol A3 comprises or consists of a polyurea dispersion polyol having a number-average molecular weight of 4000 - 8000 g / mol, preferably 5000 - 7000 g / mol.

[0071] Sentence 10: Isocyanate-reactive component according to one of sentences 1 to 9, wherein the filled polyol A3 comprises or consists of a polyurea dispersion polyol having an OH number, determined according to DIN 53240-2, as of November 2007, of 10 - 40 mg KOH / g, preferably 15 - 35 mg KOH / g, more preferably 20 - 30 mg KOH / g.

[0072] Sentence 11: Isocyanate-reactive component according to one of Sentences 1 to 10, wherein the proportion of polyether polyol A1, based on the total amount of polyol composition A, is 60

[0073] - 90 wt.%, preferably 65 - 85 wt.%, more preferably 67 - 83 wt.%, even more preferably 69 - 81 wt.%.

[0074] Sentence 12: Isocyanate-reactive component according to one of Sentences 1 to 11, wherein the proportion of polyether polyol A2, based on the total amount of polyol composition A, is 5.0

[0075] - 40.0 wt.%, preferably 10.0 - 30.0 wt.%, more preferably 12 - 28%, even more preferably 14

[0076] - 26%, most preferably 16 - 24%.

[0077] Sentence 13: Isocyanate-reactive component according to one of Sentences 1 to 12, wherein the proportion of the filled polyol A3, based on the total amount of the polyol composition A, is at least 1.0 wt.%, preferably 1.0 - 30 wt.%, more preferably 1.0 - 20.0 wt.%, even more preferably 1.0 - 10 wt.%, furthermore more preferably 1.0 - 5.0 wt.%, most preferably 1.5

[0078] - 3.0 wt.%.

[0079] Sentence 14: Isocyanate-reactive component according to one of sentences 1 to 13 comprising

[0080] Al. 50.0 - 90.0 wt.%, based on the total amount of polyol composition A, of a polyether polyol with a functionality f < 2.8, a number-average molecular weight of 2000 - 6000 g / mol, and a proportion of primary OH functions, based on the total number of terminal OH functions, of 70 - 90%, A2. 5.0 - 40.0 wt.%, based on the total amount of polyol composition A, of a polyether polyol with a functionality f > 4.0, a number-average molecular weight of 6000 - 15000 g / mol, and a proportion of primary OH functions, based on the total number of terminal OH functions, of 75 - 95%,

[0081] A3. at least 1.0 wt.% of a polyurea dispersion polyol having a number-average molecular weight of 3000 - 5000 g / mol, and

[0082] A4. 0-8.0 wt.%, based on the total amount of polyol composition A, of a polyester polyol with a functionality of 2.0 < f < 4.0 and a number-average molecular weight of 800-3000 g / mol.

[0083] Sentence 15: Isocyanate-reactive component according to sentence 14, wherein the polyol composition A consists of the components A1, A2, A3 and optionally A4 mentioned therein in the amounts mentioned therein.

[0084] Sentence 16: Isocyanate-reactive component according to one of Sentences 1 to 15 comprising

[0085] Al. 60.0 - 80.0 wt.%, based on the total amount of polyol composition A, of a polyether polyol with a functionality of 1.8 <f<2,5, einem zahlengemittelten Molekulargewicht von 2000 - 6000 g / mol und einem Anteil an primären OH-Funktionen, bezogen auf die Gesamtzahl an endständigen OH-Funktionen, von 70 - 90%,

[0086] A2. 10.0 - 30.0 wt.%, based on the total amount of polyol composition A, of a polyether polyol with a functionality of 4.0 <f<8,0, einem zahlengemittelten Molekulargewicht von 8000 - 14000 g / mol und einem Anteil an primären OH-Funktionen, bezogen auf die Gesamtzahl an endständigen OH-Funktionen, von 80 - 90%,

[0087] A3. 1.0 - 10.0 wt.% of a polyurea dispersion polyol with a number-average molecular weight of 3000 - 5000 g / mol, and

[0088] A4. 0.1 - 6.0 wt.%, based on the total amount of polyol composition A, of a polyester polyol with a functionality of 2.0 <f<4,0 und einem zahlengemittelten Molekulargewicht von 1000 - 2500 g / mol. Satz 17: Gegenüber Isocyanaten reaktive Komponente gemäß Satz 16, wobei die Polyolzusammensetzung A aus den dort genannten Bestandteilen Al, A2, A3 und A4 in den dort genannten Mengen besteht.

[0089] Sentence 18: Isocyanate-reactive component according to one of sentences 1 to 17 comprising at most 24.0 wt.%, preferably at most 16.0 wt.%, particularly preferably at most 8.0 wt.%, more preferably at most 4.0 wt.%, most preferably at most 2.4 wt.%, based on the total amount of polyol composition A, of polyether polyols having a functionality of 2.9 to 3.9.

[0090] Sentence 19: Isocyanate-reactive component according to one of sentences 1 to 18 comprising at most 8.0 wt.%, at most 5.0 wt.%, at most 3.0 wt.% or at most 2.0 wt.%, in each case based on the total amount of polyol composition A, of a vegetable oil-based polyol.

[0091] Sentence 20: Isocyanate-reactive component according to one of sentences 1 to 19 containing no or essentially no polyether polyols having at least two aromatic rings.

[0092] Sentence 21: Isocyanate-reactive component according to one of sentences 1 to 20, wherein the polyol composition A contains a polyether polyol P having a functionality of 4 - 8 and a molecular weight of more than 4000 to 7000 g / mol and an ethylene oxide content of 5 to 15 wt.%, based on the total weight of the polyether polyol P, in an amount of 0 - 1.9 wt.%, based on the total amount of compounds having isocyanate-reactive hydrogen atoms.

[0093] Sentence 22: Process for producing a polyurethane foam comprising

[0094] Reaction of the isocyanate-reactive component according to any one of sentences 1 to 21 and an isocyanate composition B comprising a di- or polyisocyanate to obtain the polyurethane foam.

[0095] Sentence 23: The process according to Sentence 22, wherein the isocyanate composition comprises or consists of an NCO prepolymer. Sentence 24: The process according to either Sentence 22 or 23, wherein components A, B, C, D, optionally E, and optionally F are each used in an amount such that an isocyanate index of 95 to 115, preferably 100 to 110, particularly preferably 103 to 108 results.

[0096] Sentence 25: Process according to any one of Sentences 22 to 24, wherein the isocyanate composition B contains no or substantially no carbodiimide-modified prepolymer.

[0097] Sentence 26: Polyurethane foam obtainable by the process according to one of the sentences 22 to 25.

[0098] Sentence 27: Polyurethane foam according to sentence 26 having a formaldehyde emission, determined according to VDA 275: 1994-07, of <0.75 mg / kg foam, preferably <0.70 mg / kg foam, particularly preferably <0.65 mg / kg foam.

[0099] Sentence 28: Polyurethane foam according to one of sentences 26 or 27 having an acetaldehyde emission, determined according to VDA275: 1994-07, of <0.15 mg / kg foam, preferably <0.10 mg / kg foam.

[0100] Sentence 29: Polyurethane foam according to one of sentences 26 to 28 having an odor rating, determined according to VDA270; C3, of <3.5, preferably <3.0.

[0101] Sentence 30: Use of an isocyanate-reactive component according to one of sentences 1 to 21 for producing a polyurethane foam with low aldehyde emission and / or low odor.

[0102] Sentence 31: Use according to sentence 30, where low aldehyde emission means that the formaldehyde emission, determined according to VDA 275: 1994-07, is <0.75 mg / kg foam, preferably <0.70 mg / kg foam, particularly preferably <0.65 mg / kg foam.

[0103] Sentence 32: Use according to one of sentences 30 or 31, where low aldehyde emission means or further means that the acetaldehyde emission, determined according to VDA275: 1994-07, is <0.15 mg / kg foam, preferably <0.10 mg / kg foam.

[0104] Sentence 33: Use according to any one of Sentences 30 to 32, where low odor means that a rating for the odor, determined according to VDA270; C3, is <3.5, preferably <3.0.

[0105] Sentence 34: Polyurethane reaction mixture comprising the isocyanate-reactive component according to any one of Sentences 1 to 21 and an isocyanate composition B comprising a di- or polyisocyanate. Sentence 35: Polyurethane reaction mixture according to Sentence 34, consisting of the isocyanate-reactive component according to any one of Sentences 1 to 21 and an isocyanate composition B comprising a di- or polyisocyanate.

[0106] Sentence 36: Polyurethane reaction mixture according to one of sentences 34 or 35, wherein the polyurethane reaction mixture comprises at most 24.0 wt.%, preferably at most 16.0 wt.%, particularly preferably at most 8.0 wt.%, more preferably at most 4.0 wt.%, most preferably at most 2.4 wt.%, based on the total amount of polyol composition A, of polyether polyols having a functionality of 2.9 to 3.9.

[0107] The invention is further described in more detail with reference to the following examples, without being limited by them.

[0108] Experiments

[0109] Raw materials used

[0110] Polyol A: 1,2-propylene glycol-initiated polyether polyol with a molecular weight of

[0111] 4000 g / mol and 80% primary OH functions, based on the total number of terminal OH functions in Polyol A

[0112] Polyol B: Glycerol-initiated polyether polyol with a molecular weight of 4500 g / mol and 87.5% primary OH functions, based on the total number of terminal OH functions in Polyol B

[0113] Polyol C: Glycerol-initiated, extended with propylene oxide and ethylene oxide endblock, with a molecular weight of 4800g / mol

[0114] Polyol D: Sorbitol-initiated polyether polyol with a molecular weight of 11800 g / mol and 84% primary OH functions, based on the total number of terminal OH functions in Polyol D

[0115] Polyol E: Dispersion of 20 wt.% solids, prepared from toluene diisocyanate and

[0116] Hydrazine hydrate, in a polyether polyol with a molecular weight of 4800 g / mol, produced by reacting glycerol with first propylene oxide and then ethylene oxide

[0117] Polyol F: Polyester polyol, made from adipic acid, trimethylolpropane, 1,2-

[0118] Propylene glycol and 1,6-hexanediol with an OH number of 109 mg KOH / g and a functionality of 3.23

[0119] Dye: ISOPUR® Black Paste N, ISL-Chemie

[0120] Catalyst 1: N-(3-Dimethylaminopropyl)-N,N-diisopropanolamine (Jeffcat DPA, Huntsman)

[0121] Catalyst 2: Mixture of N-[2-[2-(dimethylamino)ethoxy]ethyl]-N-methyl-l,3-propanediamine and 6-dimethylaminohexanol (Dabco NE 1095, Evonik)

[0122] Catalyst 3: N-[2-[2-(Dimethylamino)ethoxy]ethyl]-N-methyl-1,3-propanediamine (Dabco NE 300, Evonik)

[0123] Additive: Reaction product of ethylenediamine and 5 equivalents of propylene oxide

[0124] Stabilizer: Silicone stabilizer (Tegostab B 8734LF2, Evonik) Isocyanate: Polyisocyanate based on diphenylmethane diisocyanate and a sorbitol-initiated polyether polyol (polypropylene oxide with an OH number of 29 mg KOH / g and a functionality of 6) with an NCO content of 26 wt.% and a monomeric MDI content of 55 - 63 wt.%, Covestro Deutschland AG.

[0125] Polyurethane foams were produced from the components listed in Table 1, with all quantities of the components given therein being given in parts by weight.

[0126] To produce the foams, all components of the polyurethane reaction mixture, with the exception of the isocyanate composition, were first mixed with a stirrer in a 200 L drum for approximately 1 hour, resulting in 150 kg of a homogeneous polyol formulation (isocyanate-reactive component). The high-pressure system was then filled with both components (isocyanate-reactive component and isocyanate composition), and the temperature was set to 30 °C in each case. The two components were then mixed at a component pressure of 150 bar using a high-pressure mixing head. The resulting reaction mixture was applied to the open mold, which was then sealed. The amount of reaction mixture was selected to achieve an average foam density of 130 kg / m³. 3 After about 10 minutes, the molded parts (20x20x4 cm) intended for the emission test were 3) and the molded parts are packed in emission bags and stored at room temperature for 24 hours. Molded parts (20x20x4 cm 3 ) for mechanical tests were also demolded after 10 min and stored at room temperature for 24 hours.

[0127] Measurements were carried out on the foams obtained according to the following standards, the results of which are also shown in Table 1:

[0128] Bulk density: DIN EN ISO 845 (DBLO-bulk density)

[0129] Tensile strength: Tensile test DIN EN ISO 18798: 04 / 2008 (DBLO tensile strength)

[0130] Elongation at break: Tensile test DIN EN ISO 18798: 04 / 2008 (DBLO elongation at break)

[0131] Compressive strength: Compression test DIN EN ISO 3386-1: 10 / 2015 (DBLO compressive strength 40% compression)

[0132] Compression set: DIN EN ISO 1856-2008 (DBL0-DVR 50% compr. 22h / 70 °C)

[0133] VOC: VDA 278: 2011-10 (Thermal desorption analysis of organic emissions (volatile organic compounds, OC))

[0134] FOG: VDA 278: 2011-10 (Thermal desorption analysis of organic emissions, proportion of condensable substances (FOG) Odor: VDA 270; C3

[0135] Acetaldehyde emission: VDA 275: 1994-07

[0136] Formaldehyde emission: VDA 275: 1994-07

[0137] Table 1

[0138] In contrast to the inventive example (Polyol A), polyether polyols with a functionality of 3 were used in the comparative examples with Polyols B and C. In Comparative Example 2, a significantly larger amount of the PHD polyol (Polyol E) and a stabilizer were also used. It is clear that only with the inventive polyol composition could particularly low acetaldehyde and formaldehyde emissions according to VDA 275: 1994-07 and a low odor according to VDA 270; C3 be achieved. According to VDA 278: 2011-10, a significantly improved FOG value was also achieved with a comparable VOC value. Finally, it is shown that these improvements in the emission and odor ranges were achieved with comparable or even improved mechanical properties.

Claims

Claims 1. Isocyanate-reactive component comprising a polyol composition A comprising Al. a polyether polyol with a functionality f < 2.8, A2. a polyether polyol with a functionality f > 4.0, and A3. a filled polyol, a catalyst C, a blowing agent D, optionally further isocyanate-reactive, low molecular weight compounds E which do not fall under the polyol composition A, and optionally auxiliaries and / or additives F, wherein the isocyanate-reactive component contains essentially no stabilizer or no stabilizer at all.

2. Isocyanate-reactive component according to claim 1, wherein the polyether polyol Al has an OH number, determined according to DIN 53240-2, as of November 2007, of <56 mg KOH / g and a number-average molecular weight of >2000 g / mol.

3. Isocyanate-reactive component according to one of claims 1 or 2, wherein in the polyether polyol A1 the proportion of primary OH functions, based on the total number of terminal OH functions in A1, is 70-90% and / or in the polyether polyol A2 the proportion of primary OH functions, based on the total number of terminal OH functions in A2, is 75-95%, preferably 80-90%.

4. Isocyanate-reactive component according to one of claims 1 to 3, wherein the filled polyol A3 comprises or consists of a polyurea dispersion polyol having a number-average molecular weight of 4000-8000 g / mol, preferably 5000-7000 g / mol and / or an OH number, determined according to DIN 53240-2, as of November 2007, of 10-40 mg KOH / g, preferably 15-35 mg KOH / g, more preferably 20-30 mg KOH / g.

5. Isocyanate-reactive component according to one of claims 1 to 4, wherein the polyether polyol A2 has an OH number, determined according to DIN 53240-2, as of November 2007, of < 100 mg KOH / g, preferably < 80 mg KOH / g, more preferably < 60 mg KOH / g, - TI - most preferably 15 - 40 mg KOH / g and / or has a number average molecular weight of 6000 - 15000 g / mol.

6. Isocyanate-reactive component according to one of claims 1 to 5, wherein the proportion of polyether polyol A1, based on the total amount of polyol composition A, is 60.0 - 90.0 wt. %, preferably 65.0 - 85.0 wt. %, and / or wherein the proportion of polyether polyol A2, based on the total amount of polyol composition A, is 5.0 - 40.0 wt. %, preferably 10.0 - 30.0 wt. %.

7. Isocyanate-reactive component according to one of claims 1 to 6, wherein the polyol composition A comprises at most 24.0 wt.%, preferably at most 16.0 wt.%, particularly preferably at most 8.0 wt.%, more preferably at most 4.0 wt.%, most preferably at most 2.4 wt.%, based on the total amount of the polyol composition A, of polyether polyols having a functionality of 2.9 to 3.

9.

8. Isocyanate-reactive component according to one of claims 1 to 7, wherein the proportion of the filled polyol A3, based on the total amount of the polyol composition A, is at least 1.0 wt.%, preferably 1.0-30.0 wt.%, more preferably 1.0-20.0 wt.%, even more preferably 1.0-10.0 wt.%, furthermore more preferably 1.0-5.0 wt.%, most preferably 1.5-3.0 wt.%.

9. Isocyanate-reactive component according to one of claims 1 to 8, wherein the polyol composition A Al. 50.0 - 90.0 wt.%, based on the total amount of polyol composition A, of a polyether polyol having a functionality f < 2.8, a number-average molecular weight of 2000 - 6000 g / mol and a proportion of primary OH functions, based on the total number of terminal OH functions, of 70 - 90%, A2. 5.0 - 40.0 wt.%, based on the total amount of polyol composition A, of a polyether polyol having a functionality f > 4.0, a number-average molecular weight of 6000 - 15000 g / mol and a proportion of primary OH functions, based on the total number of terminal OH functions, of 75 - 95%, A3. at least 1.0 wt.% of a polyurea dispersion polyol having a number-average molecular weight of 3000 - 5000 g / mol, and A4. 0 - 8.0 wt.%, based on the total amount of polyol composition A, of a polyester polyol with a functionality of 2.0 <f<4,0 und einem zahlengemittelten molekulargewicht von 800 - 3000 g mol umfasst oder daraus besteht.

10. Isocyanate-reactive component according to one of claims 1 to 9, wherein the polyol composition A Al. 60.0 - 80.0 wt.%, based on the total amount of polyol composition A, of a polyether polyol with a functionality of 1.8 <f<2,5, einem zahlengemittelten molekulargewicht von 2000 - 6000 g mol und anteil an primären oh-funktionen, bezogen auf die gesamtzahl endständigen 70 90%,A2. 10.0 - 30.0 wt.%, based on the total amount of polyol composition A, of a polyether polyol with a functionality of 4.0 <f<8,0, einem zahlengemittelten molekulargewicht von 8000 - 14000 g mol und anteil an primären oh-funktionen, bezogen auf die gesamtzahl endständigen 80 90%, undA3. 1.0 - 10.0 wt.% of a polyurea dispersion polyol with a number-average molecular weight of 3000 - 5000 g / mol, A4. 0.1 - 6.0 wt.%, based on the total amount of polyol composition A, of a polyester polyol with a functionality of 2.0 <f<4,0 und einem zahlengemittelten molekulargewicht von 1000 - 2500 g mol umfasst oder daraus besteht.

11. A process for producing a polyurethane foam comprising Reaction of the isocyanate-reactive component according to any one of claims 1 to 10 and an isocyanate composition B comprising a di- or polyisocyanate to obtain the polyurethane foam.

12. Polyurethane foam obtainable by the process according to claim 11.

13. Polyurethane foam according to claim 12, wherein the polyurethane foam has a formaldehyde emission, determined according to VDA275: 1994-07, of <0.75 mg / kg foam, preferably <0.70 mg / kg foam, particularly preferably <0.65 mg / kg foam, and / or an acetaldehyde emission, determined according to VDA275: 1994-07, of <0.15 mg / kg foam, preferably <0.10 mg / kg foam and / or a rating for the odor, determined according to VDA270; C3, of <3.5, preferably <3.

0.

14. Use of an isocyanate-reactive component according to any one of claims 1 to 10 for producing a polyurethane foam with low aldehyde emission and / or low odor.

15. Use according to claim 14, wherein the polyurethane foam has a formaldehyde emission, determined according to VDA275: 1994-07, of <0.75 mg / kg foam, preferably <0.70 mg / kg foam, particularly preferably <0.65 mg / kg foam, and / or an acetaldehyde emission, determined according to VDA275: 1994-07, of <0.15 mg / kg foam, preferably <0.10 mg / kg foam and / or a rating for the odor, determined according to VDA270; C3, of <3.5, preferably <3.0.

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