Polyurethane compositions with reduced aldehyde emissions

Abstract

The present disclosure generally provides compositions having reduced aldehyde emissions, and more particularly, polyurethane compositions useful in interior components of a vehicle, such as a passenger car, where the polyurethane compositions comprise: (a) a polyfunctional isocyanate; (b) an isocyanate reactive composition; (c) a compound of formula (I); (d) a primary amine-containing compound; and (e) a catalyst.

Description

[0001] This application is a divisional application of a Chinese patent application filed on July 29, 2019, with application number 201980098848.3 and invention name “POLYURETHANE COMPOSITION WITH REDUCED ALDEHYDE EMISSIONS”. Technical Field

[0002] The present invention relates generally to polyurethane compositions having reduced aldehyde emissions, and more particularly to polyurethane compositions useful in interior components of transportation vehicles such as passenger cars. Background Art

[0003] Emissions of formaldehyde and acetaldehyde may cause unpleasant odors and health-related problems.Methods for reducing formaldehyde emissions in polyurethane or polyurea (PU) compositions by using scavenging additives are already known in the art.

[0004] US20160304686 discloses the use of acidic compounds as aldehyde scavengers in polyurethanes. However, these compounds are only used to reduce formaldehyde emissions.

[0005] WO2014026802 discloses the use of aldehyde scavengers (amine compounds) to reduce aldehyde emissions in PU foams. However, these compounds are not very effective in reducing acetaldehyde emissions.

[0006] US20060141236 discloses the use of hydrazine compounds as aldehyde scavengers in polyurethanes. However, the viscosity of these compositions is very high.

[0007] US20130203880 discloses the use of polyhydrazine dicarboxamide to reduce aldehyde emissions in polyurethane foam. However, it only works when a large amount of polyhydrazine dicarboxamide is added, which will affect the mechanical properties of PU foam.

[0008] JP2005154599 discloses some additives which can be used as aldehyde scavengers. However, such additives are not suitable for PU foam technology.

[0009] However, the known solutions fail to provide PU foam compositions which can significantly reduce both formaldehyde emissions and acetaldehyde emissions. Summary of the invention

[0010] It has now been surprisingly discovered that the compositions and methods of the present disclosure solve the above problems. Advantages of the present disclosure may include: (1) reduced aldehyde emissions, especially formaldehyde and acetaldehyde emissions; (2) low cost; and (3) no significant effect on the mechanical properties of the foam.

[0011] The present disclosure relates to compositions with reduced aldehyde emissions and methods of making these compositions. In one embodiment, the present disclosure provides a polyurethane composition comprising: (a) a polyfunctional isocyanate; (b) an isocyanate-reactive composition; (c) a compound of the formula:

[0012]

[0013] in

[0014] R1 and R2 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy,

[0015] R3 and R4 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy, provided that at least one of R3 and R4 is hydrogen,

[0016] X is S or O;

[0017] (d) a primary amine-containing compound; and (e) a catalyst.

[0018] In another embodiment, the present disclosure provides a method of preparing a polyurethane composition.

[0019] In yet another embodiment, the present disclosure provides a method of using the polyurethane composition to form an interior component of a transportation vehicle. DETAILED DESCRIPTION

[0020] The term "comprising" and its derivatives, if present herein, are not intended to exclude the presence of any additional components, steps or procedures, whether or not disclosed herein. For the avoidance of any doubt, all compositions claimed herein by use of the term "comprising" may include any additional additives, adjuvants or compounds unless otherwise indicated. Conversely, the term "consisting essentially of, if present herein, excludes from any subsequent recited scope any other components, steps or procedures, except those that are not essential to operability, and the term "consisting of, if used, excludes any components, steps or procedures not expressly described or listed. Unless otherwise specified, the term "or" refers to the listed elements individually as well as in any combination.

[0021] The articles "a" and "an" are used herein to refer to one or more than one (ie, at least one) of the grammatical object of the article. As an example, "a resin" means one resin or more than one resin.

[0022] The phrases "in one embodiment," "according to an embodiment," and the like generally indicate that a particular feature, structure, or characteristic following the phrase is included in at least one embodiment of the invention, and may be included in more than one embodiment of the invention. Importantly, such phrases do not necessarily refer to the same embodiment.

[0023] If the specification states that a component or feature "may", "can", "could", or "might" include or have a certain property, that particular component or feature is not required to include or have that property.

[0024] The present disclosure generally provides a polyurethane composition comprising: (a) a polyfunctional isocyanate; (b) an isocyanate-reactive composition; and (c) a compound of the formula:

[0025]

[0026] in

[0027] R1 and R2 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy,

[0028] R3 and R4 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy, provided that at least one of R3 and R4 is hydrogen,

[0029] X is S or O;

[0030] (d) a primary amine-containing compound; and (e) a catalyst.

[0031] According to one embodiment, the polyfunctional isocyanate comprises a compound of formula Q(NCO) n Those shown, wherein n is a number of 2 to 5, preferably 2 to 3, and Q is an aliphatic hydrocarbon group containing 2 to 18 carbon atoms, an alicyclic hydrocarbon group containing 5 to 10 carbon atoms, an aromatic aliphatic hydrocarbon group containing 8 to 13 carbon atoms, or an aromatic hydrocarbon group containing 6 to 15 carbon atoms, wherein aromatic hydrocarbon groups are generally preferred.

[0032] Examples of polyfunctional isocyanates include, but are not limited to, ethylene diisocyanate; 1,4-tetramethylene diisocyanate; 1,6-hexamethylene diisocyanate; 1,12-dodecane diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3- and -1,4-diisocyanate, and mixtures of these isomers; isophorone diisocyanate; 2,4- and 2,6-hexahydrotoluene diisocyanate and mixtures of these isomers; dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI or HMDI); 1,3- and 1,4-phenylene diisocyanate; 2,4- and 2,6-toluene diisocyanate and mixtures of these isomers (TDI); diphenylmethane-2,4'- and / or -4,4'-diisocyanate (MDI); naphthylene-1,5-diisocyanate; triphenylmethane-4,4',4 "-triisocyanates; polyphenyl-polymethylene-polyisocyanates of the type described, which can be obtained by condensation of aniline with formaldehyde and subsequent phosgenation (polymeric MDI); norbornane diisocyanate; m- and p-isocyanatophenylsulfonyl isocyanates; perchlorinated aromatic polyisocyanates; modified polyfunctional isocyanates containing carbodiimide groups, urethane groups, allophonate groups, isocyanurate groups, urea groups or biruret groups; polyfunctional isocyanates obtained by telomerization; polyfunctional isocyanates containing ester groups; and polyfunctional isocyanates containing polymerized fatty acid groups. The person skilled in the art will recognize that it is also possible to use mixtures of the abovementioned polyfunctional isocyanates, preferably mixtures of polymeric MDI, mixtures of MDI isomers and TDI mixtures.

[0033] In another embodiment, the prepolymer of MDI or TDI can also be used as an alternative to MDI or TDI. The prepolymer of MDI or TDI is prepared by reacting MDI or TDI with a multifunctional polyol. The synthesis method of MDI or TDI prepolymer is known in the art (see, for example, Polyurethanes Handbook 2nd edition, G. Oertel, 1994).

[0034] Isocyanate-reactive compositions suitable for use in the present disclosure may include a polyfunctional polyol or a polyfunctional amine.

[0035] The multifunctional polyols used in the present disclosure may include, but are not limited to, polyether polyols, polyester polyols, biorenewable polyols, polymer polyols, non-flammable polyols such as phosphorus-containing polyols or halogen-containing polyols. Such polyols may be used alone or in a suitable combination as a mixture.

[0036] The general functionality of the multifunctional polyols used in the present disclosure is 2 to 6. The molecular weight of the polyols may be in the range of 200 to 10,000, preferably 400 to 7,000.

[0037] Molecular weight (MW) is the weight average molecular weight as defined by the gel permeation chromatography (GPC) method using polystyrene as a reference.

[0038] The proportion of the polyfunctional polyol is usually in an amount of 10% to 90%, preferably 30% to 80% by weight, based on the polyurethane composition.

[0039] Polyether polyols useful in the present disclosure include alkylene oxide polyether polyols such as ethylene oxide polyether polyols and propylene oxide polyether polyols and copolymers of ethylene oxide and propylene oxide having terminal hydroxyl groups derived from polyols (including diols and triols); for example, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, pentaerythritol, glycerol, diglycerol, trimethylolpropane and similar low molecular weight polyols.

[0040] The polyester polyols used in the present disclosure include, but are not limited to, those produced by reacting dicarboxylic acids with excess diols, such as adipic acid with ethylene glycol or butanediol, or reacting lactones with excess diols, such as caprolactone with propylene glycol. In addition, the polyester polyols used in the present disclosure may also include: linear or slightly branched aliphatic (mainly adipate) polyols with terminal hydroxyl groups; low molecular weight aromatic polyesters; polycaprolactone; polycarbonate polyols. Those linear or slightly branched aliphatic (mainly adipate) polyols with terminal hydroxyl groups are produced by reacting dicarboxylic acids with excess diols, triols and mixtures thereof; those dicarboxylic acids include, but are not limited to, for example, adipic acid, AGS mixed acid; those diols, triols include, but are not limited to, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerol, trimethylolpropane and pentaerythritol. Those low molecular weight aromatic polyesters include products obtained from processing residues of dimethyl terephthalate (DMT) production (commonly referred to as DMT distillation bottoms), products obtained from glycolysis of recycled poly(ethylene terephthalate) (PET) bottles or tapes, followed by re-esterification with diacids or reaction with alkylene oxides, and products obtained from direct esterification of phthalic anhydride. Polycaprolactones are produced by ring opening of caprolactone in the presence of an initiator and a catalyst. The initiators include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerol, trimethylolpropane and pentaerythritol. Polycarbonate polyols are obtained from carbonic acid, which can be produced by polycondensation of a diol with phosgene, although transesterification of a diol (usually hexanediol) with a carbonate such as diphenyl carbonate is also possible.

[0041] Biorenewable polyols suitable for use in the present disclosure include castor oil, sunflower oil, palm kernel oil, palm oil, canola oil, rapeseed oil, soybean oil, corn oil, peanut oil, olive oil, algae oil, and mixtures thereof.

[0042] Examples of multifunctional polyols also include, but are not limited to, graft polyols or polyurea-modified polyols. Graft polyols include triols in which vinyl monomers are graft copolymerized. Suitable vinyl monomers include, for example, styrene or acrylonitrile. Polyurea-modified polyols are polyols containing polyurea dispersions formed by the reaction of diamines and diisocyanates in the presence of polyols. A variant of polyurea-modified polyols is polyisocyanate polyaddition (PIPA) polyols, which are formed by the in-situ reaction of isocyanates and alkanolamines in polyols.

[0043] The non-flammable polyol may be, for example, a phosphorus-containing polyol which can be obtained by adding an alkylene oxide to a phosphoric acid compound. The halogen-containing polyol may be, for example, those obtainable by ring-opening polymerization of epichlorohydrin or trichlorobutylene oxide.

[0044] The multifunctional amine used in the present disclosure may include polyether polyamine or polyester polyamine.

[0045] In a preferred embodiment, the isocyanate-reactive composition is a polyether polyol.

[0046] It has been found that the addition of compounds (c) and (d) to the polyurethane compositions of the present disclosure can reduce aldehyde emissions.

[0047] Compound (c) is used as an aldehyde scavenger of the present disclosure. Examples of compound (c) include, but are not limited to, barbituric acid (CAS Registry No.: 67-52-7) and thiobarbituric acid (CAS Registry No.: 504-17-6).

[0048] Compound (c) is present in the polyurethane composition in an amount of about 0.001 to about 10, preferably about 0.01 to about 5, and more preferably about 0.05 to about 2 weight percent, based on the total weight of the polyurethane composition.

[0049] When one of the three hydrogen atoms in ammonia is replaced by an alkyl or aryl group, a primary amine is formed. Primary amine-containing compounds suitable for use in the present disclosure may include compounds of the formula:

[0050]

[0051] in

[0052] R5 and R6 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy,

[0053] m is 2 or 3, n is 2, and q is 0-3.

[0054] In embodiments of the present disclosure, the primary amine-containing compound can be tetraethylenepentamine (TEPA) or dimethylaminopropylamine (DMAPA) and combinations thereof. Those skilled in the art having the benefit of the present disclosure will recognize other suitable primary amine-containing compounds for use in embodiments of the present disclosure, such as triethylenetetramine (TETA), pentaethylenehexamine (PEHA), hexaethyleneheptamine (HEHA), heptaethyleneoctamine (HEOA), octaethylenenonamine (OENO), polyetheramine products from Huntsman Corporation such as D230 amine, D400 amine, D2000 amine, EDR148 amine, EDR176 amine, ED600 amine, ED900 amine and ED2003 amines, amines obtained by addition of polyetheramines or polyvinylamines with urea or guanidine compounds, for example, amines obtained by reacting guanidine with TETA, and amines obtained by Michael addition reaction of alcohol- or amino-containing tertiary amines followed by hydrogenation, for example, amines obtained by reacting DMAPA with acrylonitrile followed by hydrogenation, and amines obtained by reacting DMEA (dimethylaminoethanol) with acrylonitrile followed by hydrogenation.

[0055] The ratio of compound (c) to compound (d) in the polyurethane composition, expressed as weight percent, is generally an amount of about 0.01:1 to about 5:1, preferably about 0.1:1 to about 3:1, and more preferably about 0.2:1 to about 2:1.

[0056] In the present disclosure, the composition further includes one or more catalysts to accelerate the reaction between the polyfunctional isocyanate and the polyfunctional polyol, for example, an amine catalyst such as N,N-dimethylethanolamine, N,N-dimethyl-N',N'-di(2-hydroxypropyl)-1,3-propylenediamine, 2-((2-(2-(dimethylamino)ethoxy)ethyl)methylamino)ethanol, dimethylcyclohexylamine and triethylenediamine.

[0057] In one embodiment, the catalyst is present in the composition in an amount of 0.001-10 wt%, preferably 0.1-5 wt%.

[0058] According to one embodiment, the NCO index of the polyurethane composition is from 0.8 to about 4, preferably from about 0.8 to about 1.3.

[0059] The isocyanate index or NCO index is the ratio of NCO groups to isocyanate-reactive hydrogen atoms present in a formulation.

[0060] [NCO]

[0061] [Active hydrogen]

[0062] In other words, the NCO index represents the amount of isocyanate actually used in the formulation relative to the amount of isocyanate theoretically required to react with the amount of isocyanate-reactive hydrogen used in the formulation.

[0063] In another embodiment, the foam composition may further optionally comprise flame retardants, antioxidants, surfactants, physical or chemical blowing agents, chain extenders, crosslinkers, foam stabilizers, fillers, pigments or any other typical additives for PU materials.

[0064] Advantages of the disclosed compositions may include: (1) reduced aldehyde emissions, especially formaldehyde and acetaldehyde emissions; (2) low cost; and (3) no significant effect on the mechanical properties of the foam.

[0065] The present disclosure also provides a method for making a polyurethane composition, comprising mixing components (b), (c), (d) and (e) to form a mixture, and adding the mixture to component (a). According to one embodiment, the ratio of compound (c) to compound (d) in the polyurethane composition expressed as a weight percentage is an amount of about 0.01:1 to about 5:1, preferably about 0.1:1 to about 3:1 and more preferably about 0.2:1 to about 2:1.

[0066] In addition, the present disclosure provides methods of using the polyurethane compositions to form interior parts of vehicles, preferably automotive interior coverings such as roof coverings, carpet backing foams, door coverings, steering rings, control knobs, and seat damping.

[0067] The embodiments of the present disclosure can also be used in other industrial fields where PU foam is used. The PU foam includes soft PU foam, semi-rigid PU foam, rigid PU foam, viscoelastic PU foam, whole skin PU foam, hydroponic PU foam, etc.

[0068] The following embodiments should now be considered as illustrative of the present disclosure, and not limiting thereof in any way.

[0069] raw materials

[0070] Multifunctional isocyanate: 80 parts by weight T 80TDI (supplier: Covestro) and 20 parts by weight of A mixture of 5005 polymeric MDI (supplier: Huntsman Corporation, USA);

[0071] Polyol A: a trifunctional copolymer of propylene oxide and ethylene oxide having terminal hydroxyl groups derived from glycerol; molecular weight is about 6000;

[0072] Polyol B: KE-880S polymer polyol. Supplier: KPX, South Korea;

[0073] Foam stabilizer: B8738LF2 polymer additive (silicone-based surfactant). Supplier: Evonik;

[0074] Catalyst A: ZF 10 catalyst (amine catalyst). Supplier: Huntsman Corporation, USA;

[0075] Catalyst B: DPA catalyst (amine catalyst). Supplier: Huntsman Corporation, USA;

[0076] Scavenger A: barbituric acid;

[0077] Scavenger B: thiobarbituric acid;

[0078] Primary amine-containing compound A: Tetraethylenepentamine

[0079] Primary amine-containing compound B: dimethylaminopropylamine

[0080] Chain extender: diethanolamine

[0081] Embodiment 1-9:

[0082] Examples 1-9 were produced using a polyfunctional isocyanate as the A component. The B components used in Examples 1-9 are shown in Table 1. All values ​​listed in Table 1 refer to the weight of the B component. As shown in Table 1, Examples 4 and 5 are comparative examples that do not include an aldehyde scavenger. Examples 6 and 7 are comparative examples that do not include a primary amine-containing compound. Example 8 is a comparative example that has too much primary amine-containing compound added. Finally, Example 9 is a comparative example that does not include an aldehyde scavenger or a primary amine-containing compound.

[0083] Table 1

[0084]

[0085]

[0086] program

[0087] For Examples 1-9, components A and B were mixed in a ratio (by weight) of A:B=44:100 and an index of 1.05, and stirred in a polyethylene container to produce polyurea / polyurethane foam. The foam composition formed was quickly poured into a polyethylene bag. The foaming reaction was carried out, and the foam was allowed to rise freely. The foam was cured at room temperature for a minimum of 15 minutes before testing, and for each formulation, about 1 kilogram (kg) of foam was produced via a manual mixing foaming procedure for VDA 276 emission tests. The temperature of the test chamber during the test was 65°C. VDA 276 (2005 edition) is a test method from Verband der Automobilindustrie (website: https: / / www.vda.de / de).

[0088] result

[0089] Formaldehyde reduction

[0090] Table 2

[0091]

[0092] 1) Tested according to VDA 276

[0093] Table 2 shows the reduction in formaldehyde emissions for Examples 1-9 tested according to the VDA 276 emissions test. When both an aldehyde scavenger and a primary amine-containing compound are present (Examples 1, 2, 3 and 8), there is a significant reduction in formaldehyde emissions. In Examples 4 and 5 (no scavenger) and Examples 6 and 7 (no primary amine-containing compound), there is a lesser reduction in formaldehyde emissions. Finally, in Example 9 (no aldehyde scavenger or primary amine-containing compound), there is no reduction in formaldehyde emissions. Comparing Examples 1, 2, 3 and 8 with Examples 4-7, it can be seen that the synergy between the aldehyde scavenger and the primary amine-containing compound reduces formaldehyde emissions more than the formaldehyde emission reduction using only the aldehyde scavenger (Examples 6 and 7) or only the primary amine-containing compound (Examples 4 and 5) alone.

[0094] Acetaldehyde reduction

[0095] Table 3

[0096] Example 1 2 3 8 9 <![CDATA[Reduction of acetaldehyde emissions 1) [%]]]> 25.47 31.6 34.2 -41.8 0

[0097] 1) Tested according to VDA276

[0098] Table 3 shows the reduction in acetaldehyde emissions for Examples 1, 2, 3, 8 and 9 tested according to the VDA276 emissions test. Examples 1-3 of the present disclosure show a reduction in acetaldehyde emissions over Example 9 (without an aldehyde scavenger or a primary amine-containing compound). When too much primary amine-containing compound is added to the composition (Example 8), there is a reduction in formaldehyde emissions (see Table 2), but an increase in acetaldehyde emissions. However, when the amount of the primary amine-containing compound of the present disclosure and the amount of the scavenger are adjusted to a suitable ratio as in Examples 1-3, there is a significant reduction in the emissions of both formaldehyde and acetaldehyde, as shown in Tables 2 and 3.

[0099] In particular, the present invention also relates to the following items:

[0100] Item 1. A polyurethane composition comprising:

[0101] (a) polyfunctional isocyanate;

[0102] (b) an isocyanate-reactive composition;

[0103] (c) a compound of the formula:

[0104]

[0105] in

[0106] R1 and R2 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy,

[0107] R3 and R4 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy, provided that at least one of R3 and R4 is hydrogen,

[0108] X is S or O,

[0109] (d) primary amine-containing compounds; and

[0110] (e) Catalyst.

[0111] Item 2. The polyurethane composition of Item 1, wherein the NCO index of the polyurethane composition is about 0.8 to about 4, preferably about 0.8 to about 1.3.

[0112] Item 3. The polyurethane composition of Item 1, wherein the polyfunctional isocyanate is selected from polymeric methylene diphenyl diisocyanate, a methylene diphenyl diisocyanate isomer mixture, a toluene diisocyanate isomer mixture, and a mixture thereof.

[0113] Item 4. The polyurethane composition of Item 1, wherein the isocyanate-reactive composition is a polyfunctional polyol or a polyfunctional amine, preferably a polyfunctional polyol, and more preferably a polyether polyol.

[0114] Item 5. The polyurethane composition of Item 1, wherein the compound (c) is at least one of barbituric acid and thiobarbituric acid.

[0115] Item 6. The polyurethane composition of Item 1, wherein the primary amine-containing compound is a compound of the following formula:

[0116]

[0117] in

[0118] R5 and R6 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy,

[0119] m is 2 or 3, n is 2, and q is 0-3.

[0120] Item 7. The polyurethane composition of Item 1, wherein the ratio of compound (c) to compound (d) in the polyurethane composition, expressed as weight percentage, is from about 0.01:1 to about 5:1, preferably from about 0.1:1 to about 3:1, and more preferably from about 0.2:1 to about 2:1.

[0121] Item 8. The polyurethane composition of Item 1, wherein the catalyst comprises an amine catalyst.

[0122] Item 9. The polyurethane composition of any one of Items 1-7, wherein the foaming composition further comprises at least one chain extender.

[0123] Item 10. A method for producing the polyurethane composition of any one of Items 1 to 8, comprising mixing compounds (b), (c), (d), and (e) to form a mixture, and adding the mixture to compound (a).

[0124] Item 11. A method of forming an interior component of a transportation vehicle using the polyurethane composition of any one of Items 1 to 9.

Claims

1. A polyurethane composition comprising: (a) polyfunctional isocyanate; (b) an isocyanate-reactive compound; (c) a compound of the formula: in R1 and R2 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy, R3 and R4 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy, provided that at least one of R3 and R4 is hydrogen, X is S or O, (d) a primary amine-containing compound of the formula: in R5 and R6 are independently selected from hydrogen, or unsubstituted or substituted alkyl, alkenyl, aryl, alkylaryl or alkoxy, m is 2 or 3, n is 2, and q is 0-3; and (e) a catalyst, The ratio of compound (c) to compound (d) in the polyurethane composition, expressed in weight percentage, is in the range of 0.2:1 to 2:

1. 2 . The polyurethane composition according to claim 1 , wherein the NCO index of the polyurethane composition is 0.8 to 4.

3. The polyurethane composition of claim 1, wherein the polyfunctional isocyanate is selected from the group consisting of polymeric methylene diphenyl diisocyanate, methylene diphenyl diisocyanate isomer mixtures, toluene diisocyanate isomer mixtures, and mixtures thereof.

4. The polyurethane composition of claim 1, wherein the isocyanate-reactive compound is a polyfunctional polyol or a polyfunctional amine.

5. The polyurethane composition according to claim 1, wherein the compound (c) is at least one of barbituric acid and thiobarbituric acid.

6. The polyurethane composition of claim 1, wherein the catalyst comprises an amine catalyst.

7. The polyurethane composition of claim 6, further comprising at least one chain extender.

8. A method of making the polyurethane composition of any one of claims 1 to 7, comprising mixing compounds (b), (c), (d) and (e) to form a mixture, and adding the mixture to compound (a).

9. A method of forming an interior part of a transportation vehicle using the polyurethane composition of any one of claims 1 to 7.

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