METHOD FOR REDUCTION OF ALDEHYDE EMISSION IN POLYURETHANE COMPRISING MATERIALS

Abstract

A reaction mixture and production method for making a polyurethane comprising material having reduced aldehyde emissions.

Claims

1. A reaction mixture for making a polyurethane material, said mixture comprising at least one isocyanate reactive compound, at least one polyisocyanate compound, and at least one aldehyde scavenger compound of the general formula [I]:
R.sub.1NHR.sub.2[I] wherein R.sub.1 and R.sub.2 are independently of one another selected from SO.sub.2R.sub.4, C(O)R.sub.5, a pyridyl derivative, CH?CHR.sub.3 or CN, R.sub.3 is SO.sub.2R.sub.4, C(O)R.sub.5, a pyridyl derivative or CN R.sub.4 is NH.sub.2, NHR.sub.6, NR.sub.7R.sub.8, OR.sub.9 or R.sub.10 R.sub.5 is H, NH.sub.2, NHR.sub.6, NR.sub.7R.sub.8, OR.sub.9 or R.sub.10 R.sub.6, R.sub.7, R.sub.8, R.sub.9, or R.sub.10 are independently of one another selected from a combination of linear, branched, saturated, unsaturated, cyclic and/or non-cyclic aliphatic hydrocarbons, araliphatic hydrocarbons, aromatic hydrocarbons and mixtures thereof, optionally comprising substituents selected from hydroxy, ether, halogen, carboxyl, isocyanate, nitro and/or amine groups, R.sub.1 and R.sub.2 may be linked to each other essentially forming a ring structure

2. The reaction mixture according to claim 1, wherein the aldehyde scavenger compound is a formaldehyde and/or acetaldehyde scavenger compound.

3. The reaction mixture according to claim 1, wherein R.sub.1 and R.sub.2 together with the NH group form a 5 to 12 membered ring structure and optionally comprise unsaturations, aromatic rings and/or heteroatoms.

4. The reaction mixture according to claim 1, wherein the pyridyl derivative is bound on the 2, 3, 4 or 5 position to the NH of the R.sub.1NHR.sub.2 formula and the pyridyl derivative is substituted with an aliphatic hydrocarbon, an araliphatic hydrocarbon and/or an aromatic hydrocarbon.

5. The reaction mixture according to claim 1, wherein the moieties R.sub.6, R.sub.7, R.sub.8, R.sub.9, or R.sub.10 are independently of one another selected from a combination of linear, branched, saturated, unsaturated, cyclic and/or non-cyclic aliphatic hydrocarbons, araliphatic hydrocarbons, aromatic hydrocarbons having 1 to 15, carbon atoms which may have substituents and mixtures thereof.

6. The reaction mixture according to claim 1, wherein the substituents are selected from one or more isocyanate-reactive groups, which advantageously comprise isocyanate-reactive hydrogen atoms selected from the group of OH, NH or NH.sub.2 groups.

7. The reaction mixture according to claim 1, wherein the aldehyde scavenger compound has a molecular weight of at most 3000 g/mol.

8. The reaction mixture according to claim 1, further comprising one or more surfactants, one or more flame retardants, water, one or more antioxidants, one or more auxiliary blowing agents, one or more urethane catalysts, or combinations thereof.

9. The reaction mixture according to claim 1, wherein the amount of the aldehyde scavenger compound is between 0.01 to 5 pbw, calculated on the total weight of the reaction mixture.

10. The reaction mixture according to claim 1, wherein the isocyanate reactive compound is selected from a polyether polyol, a polyester polyol, a polyether polyamine and/or a polyester polyamine.

11. A method for reducing the emission of aldehydes from a polyurethane comprising material, the method comprising mixing the compounds according to claim 1.

12. A method for the production of a polyurethane comprising material having reduced aldehyde emissions, the method comprising mixing the compounds according to claim 1 to obtain a foam.

13. The method according to claim 12, wherein the obtained polyurethane comprising material is a polyurethane comprising foam material having low formaldehyde emissions.

14. (canceled)

Description

DETAILED DESCRIPTION

[0051] The present invention will be described with respect to particular embodiments.

[0052] It is to be noticed that the term comprising, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, steps or components as referred to, but does not preclude the presence or addition of one or more other features, steps or components, or groups thereof. Thus, the scope of the expression a device comprising means A and B should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

[0053] Throughout this specification, reference to one embodiment or an embodiment are made. Such references indicate that a particular feature, described in relation to the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases in one embodiment or in an embodiment in various places throughout this specification are not necessarily all referring to the same embodiment, though they could. Furthermore, the particular features or characteristics may be combined in any suitable manner in one or more embodiments, as would be apparent to one of ordinary skill in the art.

[0054] It is to be understood that although preferred embodiments and/or materials have been discussed for providing embodiments according to the present invention, various modifications or changes may be made without departing from the scope and spirit of this invention.

[0055] The present invention relates to aldehyde scavenger compounds, a reaction mixture comprising said aldehyde scavenger compounds for making polyurethane materials, preferably polyurethane foam materials with reduced aldehyde emissions (more in particular formaldehyde and/or acetaldehyde emissions) and a process for making polyurethane materials with reduced aldehyde emissions.

[0056] The aldehyde scavenger compounds according to the invention are selected from one or more compounds corresponding to the general formula [I]:

R.sub.1NHR.sub.2[I] [0057] Wherein [0058] R.sub.1 and R.sub.2 are independently of one another selected from SO.sub.2R.sub.4, C(O)R.sub.5, a pyridyl derivative, CH?CHR.sub.3 or CN, [0059] R.sub.3 is SO.sub.2R.sub.4, C(O)R.sub.5, a pyridyl derivative or CN [0060] R.sub.4 is NH.sub.2, NHR.sub.6, NR.sub.7R.sub.8, OR.sub.9 or R.sub.10 [0061] R.sub.5 is H, NH.sub.2, NHR.sub.6, NR.sub.7R.sub.8, OR.sub.9 or R.sub.10 [0062] R.sub.6, R.sub.7, R.sub.8, R.sub.9, or R.sub.10 are independently of one another selected from a combination of linear, branched, saturated, unsaturated, cyclic and/or non-cyclic aliphatic hydrocarbons, araliphatic hydrocarbons, aromatic hydrocarbons and mixtures thereof, optionally comprising substituents selected from hydroxy, ether, halogen, carboxyl, isocyanate, nitro and/or amine groups, [0063] R.sub.1 and R.sub.2 may be linked to each other essentially forming a ring structure

[0064] Preferably the aldehyde scavenger compound according to the present invention are formaldehyde and/or acetaldehyde scavenger compounds. Most preferably the aldehyde scavenger compound of the present invention is a formaldehyde scavenger compound.

[0065] The pyridyl derivative according to the invention may be bound on the 2, 3, 4 or 5 position to the NH of the R.sub.1NHR.sub.2 formula. The pyridyl derivative may be substituted e.g. with aliphatic hydrocarbon, araliphatic hydrocarbon or aromatic hydrocarbon, which can also be substituted.

[0066] In one embodiment, the moieties R.sub.6, R.sub.7, R.sub.8, R.sub.9, or R.sub.10 are independently of one another selected from a combination of linear, branched, saturated, unsaturated, cyclic and/or non-cyclic aliphatic hydrocarbons, araliphatic hydrocarbons, aromatic hydrocarbons having 1 to 15, preferably 2 to 10, carbon atoms, which may have substitution and mixtures thereof. Substituents may be selected from one or more isocyanate-reactive groups, which advantageously comprise isocyanate-reactive hydrogen atoms. Groups of this kind that are isocyanate-reactive may be, for example, OH, NH or NH.sub.2 groups. Particularly preferred as isocyanate-reactive groups are one or more OH groups, more particularly an OH group.

[0067] Preferably the aldehyde scavenger compounds according to the invention have a molecular weight of at most 3000, preferably the molecular weight of the aldehyde scavenger compound is below 1500, more preferably <500.

[0068] In case R.sub.1 and R.sub.2 are linked to each other such that a ring structure is formed in the compound R.sub.1NHR.sub.2 then R.sub.1 and R.sub.2 together with the NH group may form a 5 to 14 membered ring structure. Such compounds are beneficial and preferred. Examples of said compounds having a ring structure are:

##STR00001##

[0069] The ring structure may comprise 1 or more unsaturations and/or optionally 1 or more aromatic rings and/or optionally rings with heteroatomes.

[0070] R.sub.1NHR.sub.2 compounds wherein R.sub.1 and R.sub.2 together with the NH group may form a 5 to 12 membered ring structure and further comprise unsaturations, aromatic rings and/or heteroatoms. Examples of said R.sub.1NHR.sub.2 compounds wherein R.sub.1 and R.sub.2 together with the NH group may form a 5 to 12 membered ring structure and comprise unsaturations, aromatic rings and/or heteroatomes are given below.

##STR00002## ##STR00003##

[0071] Further examples of suitable compounds wherein R.sub.1 and/or R.sub.2 comprise a ring structure are following compounds:

##STR00004##

[0072] Further, the inventors found that some of the aldehyde scavenger compounds according to formula [I] may be easily soluble in a polyisocyanate composition and/or in an isocyanate reactive composition.

[0073] The present invention further discloses a reaction mixture for making a polyurethane material, said mixture comprising at least one isocyanate reactive compound, at least one polyisocyanate compound and at least one aldehyde scavenger compound of the general formula [I]:

R.sub.1NHR.sub.2[I] [0074] Wherein [0075] R.sub.1 and R.sub.2 are independently of one another selected from SO.sub.2R.sub.4, C(O)R.sub.5, a pyridyl derivative, CH?CHR.sub.3 or CN, [0076] R.sub.3 is SO.sub.2R.sub.4, C(O)R.sub.5, a pyridyl derivative or CN [0077] R.sub.4 is NH.sub.2, NHR.sub.6, NR.sub.7R.sub.8, OR.sub.9 or R.sub.10 [0078] R.sub.5 is H, NH.sub.2, NHR.sub.6, NR.sub.7R.sub.8, OR.sub.9 or R.sub.10 [0079] R.sub.6, R.sub.7, R.sub.8, R.sub.9, or R.sub.10 are independently of one another selected from a combination of linear, branched, saturated, unsaturated, cyclic and/or non-cyclic aliphatic hydrocarbons, araliphatic hydrocarbons, aromatic hydrocarbons and mixtures thereof, optionally comprising substituents selected from hydroxy, ether, halogen, carboxyl, isocyanate, nitro and/or amine groups, [0080] R.sub.1 and R.sub.2 may be linked to each other essentially forming a ring structure And wherein the aldehyde scavenger compounds should be present in the reaction mixture in an effective amount suitable for reducing the aldehyde emission.

[0081] According to embodiments, the reaction mixture according to the invention further comprises at least a catalyst selected from blowing and/or gelling catalysts, and optionally fire retardants, antioxidants, surfactants, physical or chemical blowing agents, fillers, pigments, or any other typical additives used in polyurethane materials. These compounds are very well known in the art and can be used at any known and practically used concentration.

[0082] Using the reaction mixture according to the invention will give rise to production of polyurethane materials, preferably polyurethane foam materials with a low level of aldehyde emissions, such as the formaldehyde, preferably to a level of less than 100 ?g/m.sup.3, more preferably ?80 ?g/m.sup.3 for 1 kg foam when tested with the VDA 276 test method.

[0083] The at least one polyisocyanate compound in the reaction mixture of the invention may comprise any of the polyisocyanates known for the production of polyurethanes. These comprise the aliphatic, cycloaliphatic, and aromatic difunctional or polyfunctional isocyanates known from the prior art, and also any desired mixtures thereof. Examples are diphenylmethane 2,2-, 2,4-, and 4,4-diisocyanate, the mixtures of monomeric diphenylmethane diisocyanates with diphenylmethane diisocyanate homologs having a larger number of rings (polymer MDI), isophorone diisocyanate (IPDI) and its oligomers, tolylene 2,4- and 2,6-diisocyanate (TDI), and mixtures of these, tetramethylene diisocyanate and its oligomers, hexamethylene diisocyanate (HDI) and its oligomers, naphthylene diisocyanate (NDI), and mixtures thereof. It is preferably to use tolylene 2,4- and/or 2,6-diisocynate (TDI) or a mixture thereof, monomeric diphenylmethane diisocyanates, and/or diphenylmethane diisocyanate homologs having a larger number of rings (polymer MDI), and mixtures of these. The polyisocyanate compound used can also take the form of a polyisocyanate prepolymer. The polyisocyanate compound, according to this invention may comprise any number of polyisocyanates, including but not limited to, toluene diisocyanates (TDI), diphenylmethane diisocyanate (MDI) type isocyanates, and prepolymers of these isocyanates. Semi-prepolymers and prepolymers which may be obtained by reacting polyisocyanates with compounds containing isocyanate-reactive hydrogen atoms are also considered polyisocyanate compounds here. Examples of compounds containing isocyanate-reactive hydrogen atoms include alcohols, glycols or even relatively high molecular weight polyether polyols and polyester polyols, mercaptans, carboxylic acids, amines, urea and amides. Examples of suitable prepolymers are reaction products of polyisocyanates with monohydric or polyhydric alcohols.

[0084] Polyisocyanate prepolymers may be prepared by conventional methods, e.g. by reacting polyhydroxyl compounds which have a molecular weight of from 400 to 8000, in particular mono- or polyhydroxyl polyethers, optionally mixed with polyhydric alcohols which have a molecular weight below 400, with excess quantities of polyisocyanates, for example aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic polyisocyanates.

[0085] The at least one isocyanate reactive compound in the reaction mixture of the invention may comprise any isocyanate reactive compound selected from the group consisting of a polyether polyol, a polyester polyol, a polyether polyamine, a polyester polyamine, and/or a monool having an average molecular weight of 32-8000 and an average nominal functionality of 1-8.

[0086] Examples of suitable polyether polyols are polyethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, trimethylol propane, sorbitol, sucrose, glycerol, ethanediol, propanediol, butanediol, pentanediol, hexanediol, aromatic and/or aliphatic polyols having more carbon atoms than these compounds and having a molecular weight of up to 8000, polyester polyols having an average molecular weight of 200-8000, polyether polyester polyols having an average molecular weight of 200-8000 and polyether polyols having an average molecular weight of 200-8000. Preferably the polyether polyols are based on propylene oxide and/or ethylene oxide.

[0087] Examples of polyols are Daltocel? F555, Daltocel? F428, Daltocel? F489 and Daltocel? F442, which are all polyether triols from Huntsman.

[0088] The invention further relates to a process for making polyurethane comprising materials. Said process comprising combining and mixing at least following compounds to form a reaction mixture: [0089] at least one isocyanate compound; [0090] at least one isocyanate reactive compound; and [0091] at least one aldehyde scavenger selected from compounds corresponding to the formula [I]

R.sub.1NHR.sub.2[I] [0092] Wherein [0093] R.sub.1 and R.sub.2 are independently of one another selected from SO.sub.2R.sub.4, C(O)R.sub.5, a pyridyl derivative, CH?CHR.sub.3 or CN, [0094] R.sub.3 is SO.sub.2R.sub.4, C(O)R.sub.5, a pyridyl derivative or CN [0095] R.sub.4 is NH.sub.2, NHR.sub.6, NR.sub.7R.sub.8, OR.sub.9 or R.sub.10 [0096] R.sub.5 is H, NH.sub.2, NHR.sub.6, NR.sub.7R.sub.8, OR.sub.9 or R.sub.10 [0097] R.sub.6, R.sub.7, R.sub.8, R.sub.9, or R.sub.10 are independently of one another selected from a combination of linear, branched, saturated, unsaturated, cyclic and/or non-cyclic aliphatic hydrocarbons, araliphatic hydrocarbons, aromatic hydrocarbons and mixtures thereof, optionally comprising substituents selected from hydroxy, ether, halogen, carboxyl, isocyanate, nitro and/or amine groups, [0098] R.sub.1 and R.sub.2 may be linked to each other essentially forming a ring structure

[0099] According to a preferred embodiment, the polyurethane comprising material is a polyurethane foam and the reaction mixture comprises at least one blowing agent which may be selected from water and/or blowing agents such as CO.sub.2 and fluor based hydrocarbon compounds (hydrofluorcarbon compounds).

[0100] According to embodiments, the process for making the polyurethane comprising materials further comprises adding to the reaction mixture at least one catalyst selected from blowing and/or gelling catalysts, and optionally fire retardants, antioxidants, surfactants, physical or chemical blowing agents, fillers, pigments, or any other typical additives used in polyurethane materials. These compounds are very well known in the art and can be used at any known and practically used concentration.

[0101] According to embodiments, the amount of the aldehyde scavenger compound is from 0.01 pbw to 5 pbw, preferably from 0.05 pbw to 2 pbw, even more preferably between 0.05 pbw and 1 pbw calculated on the total weight of the reaction mixture. The amount can vary depending on the type of polyurethane that is made and the isocyanate compound and the isocyanate reactive compound that is used. Preferably the amount of the aldehyde scavenger compound is an effective amount that is able to reduce the emission of aldehydes, more in particular to reduce the emission of formaldehyde and/or acetaldehyde significantly.

[0102] According to embodiments, the process for making a polyurethane material (foam) thereby using the aldehyde scavenger compound according to the present invention is performed by combining the ingredients of the reaction mixture and this may be performed in various ways selected from step-wise, continuous or semi-continuous. The at least one aldehyde scavenger compound can first be blend with the polyisocyanate compound or can first be blend with the isocyanate reactive compound, before it is mixed with the other compounds or alternatively be added as a separate stream and then used to make polyurethane foam.

[0103] Further, the invention is related to a method for reducing the emission of aldehydes, more in particular formaldehyde and/or acetaldehyde from a polyurethane or polyurea material (foam), the method comprising mixing the compounds of the above described reaction mixture.

[0104] The present invention further relates to polyurethane materials, more in particular polyurethane foam materials made using the process according to the invention and making use of the aldehyde scavenger compounds according to the present invention and the use of said materials. The polyurethane materials comprise polyisocyanate polyaddition products, for example thermosets, and foams based on polyisocyanate polyaddition products, for example flexible foams, semi rigid foams, rigid foams, and integral foams and also polyurethane coatings and binders.

[0105] According to embodiments, the polyurethane foam according to the invention is a flexible or semi-rigid foam and the NCO index of the reaction mixture used for making said foam is in the range of from about 80 to about 150, preferably from about 90 to about 130.

[0106] According to embodiments, the polyurethane foam according to the invention is a rigid foam and the NCO index of the foam composition is in the range of from about 105 to about 1000, preferably from about 105 to about 400.

[0107] The polyurethane material (foam) of the invention is preferably used in furniture and/or automotive applications.

[0108] The invention is now illustrated with below reference to the examples.

EXAMPLES

[0109] Chemicals used: [0110] Suprasec? 2447 polyisocyanate compound obtained from Huntsman [0111] Daltocel? F428, polyol obtained from Huntsman [0112] Jeffcat? ZE10, blowing catalyst available from Huntsman [0113] Jeffcat? DPA, gelling catalyst obtained from Huntsman [0114] Diethanolamine, chain extender obtained from Huntsman [0115] Tegostab? B8734LF2, surfactant available from Evonik
Suprasec?, Jeffcat? and Daltocel? are trademarks of the Huntsman Corporation or an Affiliate thereof and have been registered in one or more but not all countries.

[0116] The following examples show reaction mixture for making PU foam materials according to the invention and comparative examples using reaction mixture for making PU foam materials without aldehyde scavengers and the emission results obtained on the PU foam using the VDA-276 test.

Example 1

[0117] Table 1 shows the compositions of reaction mixtures for making a polyurethane foam and the formaldehyde emissions measured on the obtained foams. Example 1 is according to the invention using a reaction mixture whereto succinimide was added (all ingredients expressed in gram). The comparative example (comp1) is using a reaction mixture whereto no aldehyde scavenger is added.

TABLE-US-00001 TABLE 1 Composition of reaction mixtures used to make PU foams and result of the formaldehyde emission. Comp 1 Example 1 Daltocel? F428 100 100 Water 4 4 Jeffcat? ZF10 0.1 0.1 Jeffcat? DPA 1 1 Diethanolamine 0.3 0.3 Tegostab? B8734LF2 0.9 0.9 Succinimide .sup.(2) 0.3 Suprasec? S2447 60 60 VDA 276 formaldehyde emissions, ?g/m3 .Math. kg foam 144 51 .sup.(2) compound first added to the isoreactive (polyol) blend.

Examples 2-3

[0118] Table 2 shows the compositions of reaction mixtures for making a polyurethane foam and the formaldehyde emissions measured on the obtained foams. Examples 2-3 are according to the invention using a reaction mixture whereto phtalamide or saccharin was added (all ingredients expressed in gram). The comparative example (comp2) is using a reaction mixture whereto no aldehyde scavenger is added.

TABLE-US-00002 TABLE 2 Composition of reaction mixtures used to make PU foams and result of the formaldehyde emission. Comp 2 Example 2 Example 3 Daltocel? F428 100 100 100 Water 4 4 4 Jeffcat? ZF10 0.1 0.1 0.1 Jeffcat? DPA 1 1 1 Diethanolamine 0.3 0.3 0.3 Tegostab? B8734LF2 0.9 0.9 0.9 Phtalamide (2) 0.3 Saccharin (2) 0.3 Suprasec? S2447 60 60 60 VDA 276 formaldehyde emissions, 114 59 80 ?g/m3 .Math. kg foam (2) compound first added to the isoreactive (polyol) blend.

Examples 4-9

[0119] Table 2 shows the compositions of reaction mixtures for making a polyurethane foam and the formaldehyde emissions measured on the obtained foams. Examples 4-9 are according to the invention using a reaction mixture whereto 5-nitroisoindoline-1,3-dione, 5,5-dimethylimidazolidine-2,4-dione, N-(6-methylpyridin-2-yl)acetamide, pyrimidine-2,4,6(1H, 3H, 5H)-trione or N-((4-aminophenyl)sulfonyl)acetamide was added as aldehyde scavenger compound (all ingredients expressed in gram). The comparative example (comp3) is using a reaction mixture whereto no aldehyde scavenger is added. The formaldehyde emissions were measured with an alternative measurement method instead of using the VDA 276. A microscale chamber analysis was performed at 65C for 3 hours using air flow rate of 40 ml/min on a foam sample weight of 0.7500 gram (gas regulator 14 psi). typically higher emissions values are measured compared to the VDA 276 test.

TABLE-US-00003 TABLE 3 Composition of reaction mixtures used to make PU foams and result of the formaldehyde emission. Comp Example Example Example Example Example Example 3 4 5 6 7 8 9 Daltocel F428 100 100 100 100 100 100 100 Water 4 4 4 4 4 4 4 Jeffcat ZF10 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Jeffcat DPA 1 1 1 1 1 1 1 Diethanolamine 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Tegostab B8734LF2 0.9 0.9 0.9 0.9 0.9 0.9 0.9 5-nitroisoindoline-1,3-dione (2) 0.3 5,5-dimethylimidazolidine-2,4-dione (2), 0.3 N-(6-methylpyridin-2-y1)acetamide (2) 0.3 N-(6-methylpyridin-2-yl)acetamide (3) 0.3 pyrimidine-2,4,6(1H,3H,5H)-trione (2) 0.3 N-((4-aminophenyl)sulfony1)acetamide (2) 0.3 Suprasec S2447 60 60 60 60 60 60 60 Micro-scale chamber analysis at 65? C. 402 76 189 334 330 10 208 (2) compound first added to the isoreactive (polyol) blend. (3) compound first added to the isocyanate blend.