Tertiary amine catalysts for polyurethane foams.

Abstract

A piperazine-based tertiary amine catalyst for use in polyurethane formulations, the polyurethane formulations comprising a piperazine-based tertiary amine catalyst, a compound containing an isocyanate functional group, an active hydrogen-containing compound, and optionally one or more of a blowing agent and additives.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63 / 403,932, filed September 6, 2022. The cited application(s) are incorporated herein by reference.

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not applicable

[0003] FIELD OF THE DISCLOSURE This disclosure relates generally to tertiary amine catalysts for use in the production of flexible foams and other polyurethane materials. [Background technology]

[0004] Polyurethane foams are widely known and are used in a variety of applications, including those in the automotive and housing industries. These foams are produced by the reaction of polyisocyanates with polyols in the presence of various additives. One such additive is an amine catalyst, which is used to accelerate blowing (the reaction of water with polyisocyanates to produce CO2) and gelation (the reaction of polyols with polyisocyanates).

[0005] Disadvantages of using conventional amine catalysts (e.g., triethylenediamine, bisdimethylaminoethyl ether) in polyurethane foam production include safety and toxicity issues due to their high volatility and resulting airborne vapor emissions. Various attempts have been made to reduce such emissions by adding functional groups to the amine catalyst or increasing its molecular weight. However, polyurethane foams produced using these improved catalysts still emit vapors due to the thermal and / or hydrolytic instability of the covalent bond between the amine catalyst and the polyurethane polymer. Therefore, it is desirable to improve the performance of known amine catalysts commonly used in the art in polyurethane foam production. Summary of the Invention

[0006] The present disclosure provides polyurethane formulations that include a piperazine-based tertiary amine catalyst, a compound containing an isocyanate functionality, and an active hydrogen-containing compound.

[0007] According to another embodiment, there is provided a catalyst package for use in forming a polyurethane material comprising a piperazine-based tertiary amine catalyst and a second component selected from an amine catalyst containing at least one tertiary amine group, a non-amine catalyst, a halogenated olefin compound, and mixtures thereof.

[0008] In yet another embodiment, there is provided a method for forming a polyurethane material, comprising contacting a compound containing an isocyanate functionality, an active hydrogen-containing compound, and optionally one or more of a blowing agent and additive(s) in the presence of a piperazine-based tertiary amine catalyst. [Brief explanation of the drawings]

[0009] [Figure 1] 1 shows the apparatus used in the polycarbonate staining test of Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following terms shall have the following meanings:

[0011] The term "comprising" and its derivatives are not intended to exclude the presence of any additional component, step, or procedure, whether or not disclosed herein. For the avoidance of doubt, all compositions claimed herein through the use of the term "comprising" may include any additional additive or compound, unless stated to the contrary. In contrast, the term "consisting essentially of," as used herein, excludes from the scope of any succeeding description any other component, step, or procedure, except those that are not essential to operability, and the term "consisting of," when used, excludes any component, step, or procedure not specifically described or listed. The term "or," unless otherwise stated, refers to the listed members individually or in any combination.

[0012] The articles "a" and "an" are used herein to refer to one or more (i.e., at least one) of the grammatical object of the article. By way of example, "a catalyst" means one catalyst or multiple catalysts. The phrases "in one embodiment," "according to one embodiment," and the like generally mean that the particular feature, structure, or characteristic that follows the phrase is included in at least one embodiment of the present disclosure and may be included in multiple embodiments of the present disclosure. Importantly, such phrases do not necessarily refer to the same aspect. When a statement herein states that a component or feature "may," "can," "could," or "might" be included or have a characteristic, it does not require that the particular component or feature be included or have that characteristic.

[0013] The term "about," as used herein, allows for a degree of variation in a value or range, for example, it may be within 10%, within 5%, or within 1% of a stated value or stated range limit.

[0014] Values ​​expressed in range format should be interpreted in an open manner to include not only the numerical values ​​expressly recited as the limits of the range, but also all individual numerical values ​​or subranges subsumed within that range, as if each numerical value and subrange were expressly recited. For example, a range (such as 1 to 6) should be considered to specifically disclose subranges (such as 1 to 3, 2 to 4, 3 to 6, etc.) as well as individual numbers within that range (e.g., 1, 2, 3, 4, 5, and 6). This applies regardless of the breadth of the range.

[0015] The terms "preferred" and "preferably" refer to embodiments that may offer certain benefits, under certain circumstances, while other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the present disclosure.

[0016] The term "substantially free" refers to the amount of a particular compound or moiety present in a composition that does not significantly affect the composition.In some embodiments, "substantially free" can refer to the amount of a particular compound or moiety present in a composition being less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%, or less than 0.1 wt%, or less than 0.05 wt%, or even less than 0.01 wt%, based on the total weight of the composition, or can refer to the amount of that particular compound or moiety being completely absent in each composition.

[0017] Where a substituent is specified by its conventional chemical formula (written from left to right), such substituent is intended to equally encompass the chemically identical substituent that would be obtained by writing the structure from right to left, e.g., -CHO- is equivalent to -OCH-.

[0018] The term "alkyl" refers to a straight- or branched-chain saturated hydrocarbon group having 1 to 10 carbon atoms. In some embodiments, the alkyl substituent can be a lower alkyl group. The term "lower" refers to an alkyl group having 1 to 5 carbon atoms. Examples of "lower alkyl groups" include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, and butyl groups.

[0019] The term "halogenated olefin" refers to an olefinic compound or moiety that may contain fluorine, chlorine, bromine, or iodine.

[0020] The term "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes cases where the event or circumstance occurs and cases where it does not occur.

[0021] The present disclosure is generally directed to a piperazine-based tertiary amine catalyst and its use in polyurethane formulations, which may include one or more of an isocyanate-functional compound, an active hydrogen-containing compound, and optionally a blowing agent and additive(s). The present disclosure is also directed to a catalyst package for use in forming polyurethane materials, which includes the piperazine-based tertiary amine catalyst and a second component selected from an amine catalyst containing at least one tertiary amine group, a non-amine catalyst, a halogenated olefin compound, and mixtures thereof. The present disclosure is further directed to rigid or flexible polyurethane foams or other polyurethane materials made from formulations containing the piperazine-based tertiary amine catalyst, an isocyanate-functional compound, an active hydrogen-containing compound, and optionally one or more of a blowing agent and additive(s) described herein. The term "polyurethane," as used herein, is understood to encompass pure polyurethanes, polyurethane polyureas, and pure polyureas. Surprisingly, it has been found that when the piperazine-based tertiary amine catalysts of the present disclosure are used in the production of polyurethane foams, the amine catalysts are capable of forming highly stable covalent bonds within the polyurethane matrix, such that the polyurethane foams exhibit low (or substantially no) amine emissions. Because of this stability, contact of the polyurethane foam with the surface of another material (such as polycarbonate) at elevated temperatures and / or humidity conditions does not damage or contaminate the material.

[0022] According to one embodiment, the piperazine-based tertiary amine catalyst is Formula (1) [ka] is a compound represented by wherein n is an integer from 0 to about 25; AO is an alkyl oxide independently selected at each AO unit from —CHO—, —CHO—, and —CHO—; R is methyl, ethyl, isopropyl, or —RR—X, where R and R are independently selected from methyl, ethyl, and isopropylamino groups; and X is a lower alkyl group optionally interrupted by an oxygen atom. In one embodiment, n is an integer less than about 20, or less than about 15, or less than about 10, or less than about 5. In another embodiment, n is an integer of at least about 2, or at least about 5, or at least about 10. In yet another embodiment, n is an integer of from about 1 to about 15, or from about 2 to about 10, or from about 3 to about 8, or from about 4 to about 6.

[0023] In another embodiment, AO in the piperazine-based tertiary amine catalyst of formula (1) is independently selected from -C2H4O- and -C3H6O- in each AO unit. In yet another embodiment, AO in each AO unit is -C3H6O-, while in another embodiment, AO in each AO unit is -C2H4O-. In yet another embodiment, R2 in the piperazine-based tertiary amine catalyst of formula (1) is methyl or ethyl.

[0024] According to some embodiments, the piperazine-based tertiary amine catalyst of Formula (1) can be used alone in forming polyurethane foams or polyurethane materials. In still other embodiments, the piperazine-based tertiary amine catalyst can be combined with an amine catalyst or a non-amine catalyst containing at least one tertiary amine group, or a mixture thereof, in forming polyurethane foams or polyurethane materials. In embodiments in which the piperazine-based tertiary amine catalyst of Formula (1) is combined with an amine catalyst or a non-amine catalyst containing at least one tertiary amine group, or a mixture thereof, the weight ratio of the piperazine-based tertiary amine catalyst of Formula (1) to the amine catalyst or a non-amine catalyst containing at least one amine group, or a mixture thereof, is at least 1:1, in some embodiments at least 1.5:1, in still other embodiments at least 2:1, in further embodiments at least 5:1, while in other further embodiments at least 10:1. In still other embodiments, the weight ratio of the piperazine-based tertiary amine of Formula (1) to the amine catalyst or non-amine catalyst containing at least one amine group or mixtures thereof is 0.1:99.9 to 99.9:0.1, in yet other embodiments 1:99 to 99:1, in yet other embodiments 5:95 to 95:5, in further embodiments 10:90 to 90:10, while in yet further embodiments 25:75 to 75:25.

[0025] Representative amine catalysts containing at least one tertiary group include, but are not limited to, bis-(2-dimethylaminoethyl)ether (commercially available as JEFFCAT® ZF-20 catalyst), N,N,N'-trimethyl-N'-hydroxyethyl bisaminoethyl ether (commercially available as JEFFCAT® ZF-10 catalyst), N-(3-dimethylaminopropyl)-N,N-diisopropanolamine (commercially available as JEFFCAT® DPA catalyst), N,N-dimethylethanolamine (commercially available as JEFFCAT® DMEA catalyst), triethylenediamine (commercially available as JEFFCAT® TEDA catalyst), blends of N,N-dimethylethanolamine and ethylenediamine (including those commercially available as JEFFCAT® TD-20 catalyst), N,N-dimethylcyclohexyl N,N,N',N",N"-pentamethyldipropylenetriamine (commercially available as JEFFCAT® ZR-40 catalyst), N,N-bis(3-dimethylaminopropyl)-N-isopropanolamine (commercially available as JEFFCAT® ZR-50 catalyst), N'-(3-(dimethylamino)propyl)-N,N-dimethyl-1,3-propanediamine (commercially available as JEFFCAT® Z-130 catalyst), 2-(2-dimethylaminoethoxy)ethanol (commercially available as JEFFCAT® ZR-70 catalyst), N,N,N-trimethylaminoethyl-ethanolamine (commercially available as JEFFCAT® Z-110 catalyst), N-ethylmorpholine (commercially available as JEFFCAT® NEM catalyst), N-methylmorpholine (commercially available as JEFFCAT® NMM catalyst), 4-methoxyethylmorpholine, N,N'-dimethylpiperazine (commercially available as JEFFCAT® DMP catalyst), 2,2'-dimorpholinodiethyl ether (commercially available as JEFFCAT® DMDEE catalyst), 1,3,5-tris(3-(dimethylamino)propyl)-hexahydro-s-triazine (JEFFCAT® T R-90 catalyst), 1-propanamine, 3-(2-(dimethylamino)ethoxy), substituted imidazoles (such as 1,2-dimethylimidazole and 1-methyl-2-hydroxyethylimidazole), bis-substituted piperazines (such as aminoethylpiperazine, N,N',N'-trimethylaminoethylpiperazine or bis-(N-methylpiperazine)urea), N-methylpyrrolidine and substituted methylpyrrolidines (such as 2-aminoethyl-N-methylpyrrolidine or bis-(N-methylpyrrolidine)ethylurea), 3-dimethylaminopropylamine, N,N,N",N"-tetramethyldipropylenetriamine, tetramethylguanidine, 1,2-bis-diisopropanol. Other examples of amine catalysts include N-alkylmorpholines (such as N-butylmorpholine and dimorpholinodiethyl ether), N,N'-dimethylaminoethanol, N,N-dimethylaminoethoxyethanol, bis-(dimethylaminopropyl)-amino-2-propanol, bis-(dimethylamino)-2-propanol, bis-(N,N-dimethylamino)ethyl ether, N,N,N'-trimethyl-N'hydroxyethyl-bis-(aminoethyl)ether, N,N-dimethylaminoethyl-N'-methylaminoethanol, 1-[2-(dimethylamino)ethyl]piperazine, and tetramethyliminobispropylamine. The aforementioned JEFFCAT® catalyst is commercially available from Huntsman Petrochemical LLC, The Woodlands,Available from Texas.

[0026] Other amine catalysts that may be used in the present disclosure may be found in Appendix D, pages D.1-D.23 of "Dow Polyurethanes Flexible Foams" by Herrington et al. (1997), which is incorporated herein by reference. Further examples may be found in "JEFFCAT® Amine Catalysts for the Polyurethane Industry," version JCT-0910, which is incorporated herein by reference.

[0027] Non-amine catalysts are compounds (or mixtures thereof) that have catalytic activity for the reaction of isocyanate groups with polyols or water, but are not included in the above description of amine catalysts. Examples of such additional non-amine catalysts include, for example, tertiary phosphines (such as trialkylphosphines and dialkylbenzylphosphines); chelates of various metals (such as those obtainable from acetylacetone, benzoylacetone, trifluoroacetylacetone, ethyl acetoacetate, and the like, with metals (such as Be, Mg, Zn, Cd, Pd, Ti, Zr, Sn, As, Bi, Cr, Mo, Mn, Fe, Co, and Ni); metal carboxylates (such as potassium acetate and sodium acetate); acidic metal salts of strong acids (such as ferric chloride, stannic chloride, stannous chloride, antimony trichloride, bismuth nitrate, and bismuth chloride); strong bases (such as alkali metal hydroxides and alkaline earth metal hydroxides, alkoxides, and phenoxides); alcoholates and phenolates of various metals (such as Ti(OR)). 6 )4, Sn(OR 6 )4, and Al(OR 6 )3(R 6where N,N-dialkylamino)alcohols; alkaline earth metal, Bi, Pb, Sn, or Al carboxylates; and tetravalent tin compounds, and trivalent or pentavalent bismuth, antimony, or arsenic compounds.

[0028] The piperazine-based tertiary amine catalyst of Formula (1) can be used in a catalytically effective amount to catalyze the reaction between a compound containing an isocyanate functional group and an active hydrogen-containing compound to produce rigid or flexible polyurethane foams or other polyurethane materials. A catalytically effective amount of the piperazine-based tertiary amine catalyst of Formula (1) can range from about 0.01 to 15 parts per 100 parts of active hydrogen-containing compound, in some embodiments from about 0.05 to 12.5 parts per 100 parts of active hydrogen-containing compound, in another further embodiment from about 0.1 to 7.5 parts per 100 parts of active hydrogen-containing compound, and in yet another further embodiment from about 0.5 to 5 parts per 100 parts of active hydrogen-containing compound.

[0029] In one embodiment, the compound containing isocyanate functionality is a polyisocyanate, an isocyanate-terminated prepolymer, or a mixture thereof.

[0030] Polyisocyanates have the general formula Q(NCO) a where a is a number from 2 to 5 (e.g., 2 to 3), and Q is an aliphatic hydrocarbon group containing 2 to 18 carbon atoms, a cycloaliphatic hydrocarbon group containing 5 to 10 carbon atoms, an araliphatic hydrocarbon group containing 8 to 13 carbon atoms, or an aromatic hydrocarbon group containing 6 to 15 carbon atoms.

[0031] Examples of polyisocyanates 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-diisocyanate and cyclohexane-1,4-diisocyanate, and mixtures of these isomers; isophorone diisocyanate; 2,4-hexahydrotoluene diisocyanate and 2,6-hexahydrotoluene diisocyanate, and mixtures of these isomers; dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI, i.e., HMDI); 1,3-phenylene diisocyanate and 1,4-phenylene diisocyanate; 2 ,4-toluene diisocyanate 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"-triisocyanate; polyphenyl-polymethylene-polyisocyanates of the type obtainable by condensation of aniline with formaldehyde followed by phosgenation (crude MDI); norbornane diisocyanate; m-isocyanatophenylsulfonyl isocyanate and p-isocyanatophenylsulfonyl isocyanate; perchlorinated aryl polyisocyanates; polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups These include modified polyisocyanates containing isocyanurate, urea, or biruret groups; polyisocyanates obtained by telomerization reactions; polyisocyanates containing ester groups; and polyisocyanates containing polymeric fatty acid groups. Those skilled in the art will recognize that mixtures of the above polyisocyanates may also be used.

[0032] Isocyanate-terminated prepolymers may also be used in preparing polyurethanes. They may be prepared by reacting an excess of a polyisocyanate or mixture thereof with a small amount of an active hydrogen-containing compound as determined by the well-known Zerewitinoff test.

[0033] In another embodiment, the active hydrogen-containing compound is a polyol. Polyols suitable for use in the present disclosure include, but are not limited to, polyalkylene ether polyols, polyester polyols, polymer polyols, non-flammable polyols (such as phosphorus-containing polyols or halogen-containing polyols). Such polyols can be used alone or in suitable combinations as a mixture.

[0034] Polyalkylene ether polyols include poly(alkylene oxide) polymers (such as poly(ethylene oxide) polymers and poly(propylene oxide) polymers) and copolymers with terminal hydroxyl groups derived from polyhydric compounds including diols and triols, such as 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.

[0035] Polyester polyols include, but are not limited to, those made by reacting a dicarboxylic acid with an excess of a diol (e.g., adipic acid with ethylene glycol or butanediol) or those made by reacting a lactone with an excess of a diol (such as caprolactone with propylene glycol).

[0036] In addition to polyalkylene ether polyols and polyester polyols, polymer polyols are also suitable for use in the present disclosure. The use of polymer polyols in polyurethane materials increases resistance to deformation (e.g., improving the load-bearing properties of the foam or material). Examples of polymer polyols include, but are not limited to, graft polyols or polyurea-modified polyols (Polyharnstoff Dispersion Polyols). Graft polyols include triols graft-copolymerized with vinyl monomers. Suitable vinyl monomers include, for example, styrene or acrylonitrile. Polyurea-modified polyols are polyols containing polyurea dispersions formed by reacting diamines and diisocyanates in the presence of a polyol. A different form of polyurea-modified polyol is polyisocyanate polyaddition (PIPA) polyol, formed by the in situ reaction of isocyanates and alkanolamines in the polyol.

[0037] The non-flammable polyol may be, for example, a phosphorus-containing polyol obtainable by addition of an alkylene oxide to a phosphoric acid compound. The halogen-containing polyol may be, for example, one obtainable by ring-opening polymerization of epichlorohydrin or trichlorobutylene oxide.

[0038] The polyurethane formulation may also contain one or more blowing agents. In one embodiment, a halogenated olefin compound may serve as the blowing agent. The halogenated olefin compound includes at least one haloalkene (e.g., a fluoroalkene or a chlorofluoroalkene) containing 3 to 4 carbon atoms and at least one carbon-carbon double bond. Suitable compounds may include hydrohaloolefins such as trifluoropropene, tetrafluoropropene (e.g., tetrafluoropropene (1234)), pentafluoropropene (e.g., pentafluoropropene (1225)), chlorotrifluoropropene (e.g., chlorotrifluoropropene (1233)), chlorodifluoropropene, chlorotrifluoropropene, chlorotetrafluoropropene, hexafluorobutene (e.g., hexafluorobutene (1336)), or combinations thereof. In certain embodiments, the tetrafluoropropene compounds, pentafluoropropene compounds, and / or chlorotrifluoropropene compounds have no more than one fluorine or chlorine substituent attached to the terminal carbon atom of the unsaturated carbon chain (e.g., 1,3,3,3-tetrafluoropropene (1234ze), 1,1,3,3-tetrafluoropropene, 1,2,3,3,3-pentafluoropropene (1225ye), 1,1,1-trifluoropropene, (Z)-1,1,1,2,3-pentafluoropropene (1225yc), (Z)-1,1,1,2,3-pentafluoropropene (1225yez), 1-chloro-3,3,3-trifluoropropene (1233zd), 1,1,1,4,4,4-hexafluorobut-2-ene (1336mzzm), or combinations thereof).

[0039] Other blowing agents that can be used alone or in combination with the above-mentioned halogenated olefin compounds include air, nitrogen, carbon dioxide, hydrofluorocarbons ("HFCs"), alkanes, alkenes, monocarboxylates, ketones, ethers, or combinations thereof. Suitable HFCs include 1,1-difluoroethane (HFC-152a), 1,1,1,2-tetrafluoroethane (HFC-134a), pentafluoroethane (HFC-125), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3,3-pentafluorobutane (HFC-365mfc), or combinations thereof. Suitable alkanes and alkenes include n-butane, n-pentane, isopentane, cyclopentane, 1-pentene, or combinations thereof. Suitable monocarboxylates include methyl formate, ethyl formate, methyl acetate, or combinations thereof. Suitable ketones and ethers include acetone, dimethyl ether, or combinations thereof.

[0040] Furthermore, the polyurethane formulation may optionally contain one or more additives. Examples of additives include, but are not limited to, crosslinkers, cell stabilizers, surfactants, chain extenders, pigments, fillers, flame retardants, thermally expandable microspheres, water, thickeners, smoke suppressants, reinforcing agents, antioxidants, UV stabilizers, antistatic agents, infrared absorbers, dyes, mold release agents, antifungal agents, biocides, or any combination thereof. In some embodiments, the above-mentioned amine catalysts and non-amine catalysts containing at least one tertiary group may also be considered additives.

[0041] Crosslinkers can include, for example, polyhydric alcohols (especially trihydric alcohols such as glycerol and trimethylolpropane), polyamines, and combinations thereof. Non-limiting examples of polyamine crosslinkers include diethyltoluenediamine, chlorodiaminobenzene, diethanolamine, diisopropanolamine, triethanolamine, tripropanolamine, 1,6-hexanediamine, and combinations thereof. Typical diamine crosslinkers contain 12 or fewer carbon atoms, more commonly 7 or fewer carbon atoms.

[0042] The cell stabilizer may include, for example, a silicone surfactant or an anionic surfactant. Examples of suitable silicone surfactants include, but are not limited to, polyalkylsiloxane, polyoxyalkylene polyol-modified dimethylpolysiloxane, alkylene glycol-modified dimethylpolysiloxane, or any combination thereof.

[0043] Suitable surfactants (or surface active agents) include emulsifiers and foam stabilizers (such as silicone surfactants known in the art, e.g., polysiloxanes), as well as various amine salts of fatty acids (such as diethylamine oleate or diethanolamine stearate), and the sodium salt of ricinoleate.

[0044] Examples of chain extenders include, but are not limited to, compounds having hydroxyl or amino functional groups, such as glycols, amines, diols, and water. Further non-limiting examples of chain extenders include ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, ethoxylated hydroquinone, 1,4-cyclohexanediol, N-methylethanolamine, N-methylisopropanolamine, 4-aminocyclohexanol, 1,2-diaminoethane, or any mixture thereof.

[0045] Pigments can be used to coat polyurethane materials during manufacturing to identify product grades or to hide yellowing. Pigments can include any suitable organic or inorganic pigment. For example, organic pigments or colorants include, but are not limited to, azo / diazo dyes, phthalocyanines, dioxazines, or carbon black. Examples of inorganic pigments include, but are not limited to, titanium dioxide, iron oxide, or chromium oxide.

[0046] Fillers may be used to increase the density and load-bearing properties of the polyurethane foam or material. Suitable fillers include, but are not limited to, barium sulfate, carbon black, or calcium carbonate.

[0047] Flame retardants can be used to reduce flammability, for example, but not limited to, chlorinated phosphate esters, chlorinated paraffins, or melamine powder.

[0048] Thermally expandable microspheres include those containing (cyclo)aliphatic hydrocarbons. These microspheres are generally unexpanded or partially unexpanded dry microspheres consisting of small spherical particles, typically 10-15 microns in average diameter. The spheres are formed from a gas-impermeable polymer shell (e.g., made of acrylonitrile or PVDC) encapsulating minute droplets of (cyclo)aliphatic hydrocarbons (e.g., liquid isobutane). When such microspheres are subjected to heat at elevated temperatures (e.g., 150-200°C) sufficient to soften the thermoplastic shell and volatilize the encapsulated (cyclo)aliphatic hydrocarbons, the resulting gas expands the shell and increases the volume of the microsphere. Upon expansion, the diameter of the microsphere increases by 3.5-4 times its original diameter, resulting in an expanded volume of the microsphere approximately 50-60 times greater than the initial volume of the microsphere in its unexpanded state. An example of such microspheres are EXPANCEL®-DU microspheres marketed by AKZO Nobel Industries of Sweden.

[0049] Methods for generally producing polyurethane materials from polyurethane formulations are described, for example, in U.S. Patent Nos. 5,420,170, 5,648,447, 6,107,359, 6,552,100, 6,737,471, and 6,790,872, the contents of which are incorporated herein by reference. Piperazine-based tertiary amine catalysts can be used to make a variety of polyurethane materials, including rigid foams, flexible foams, semi-rigid foams, microcellular elastomers, textile backings, spray elastomers, cast elastomers, polyurethane-isocyanurate foams, reaction injection molded polymers, structural reaction injection molded polymers, and the like.

[0050] 15 to 150 kg / m containing a piperazine-based tertiary amine catalyst of formula (1) 3A non-limiting example of a typical flexible polyurethane foam formulation (e.g., for automobile seating) having a density of 1000 MPa may include the following components in parts by weight (pbw): [Table 1]

[0051] 15 to 70 kg / m containing piperazine-based tertiary amine of formula (1) 3 A non-limiting example of a typical rigid polyurethane foam formulation having a density of 1000 ppm may include the following components in parts by weight (pbw): [Table 2]

[0052] The amount of compound containing isocyanate functionality is not limited, but is generally within the range known to those skilled in the art. The exemplary ranges given above are indicated by reference to the Isocyanate Index, which is defined as the number of equivalents of isocyanate divided by the total number of equivalents of active hydrogen multiplied by 100.

[0053] Thus, in yet another embodiment, the present disclosure provides a method for producing a polyurethane material comprising contacting a compound containing an isocyanate functional group, an active hydrogen-containing compound, and optionally one or more of a blowing agent and additive(s) in the presence of a piperazine-based tertiary amine catalyst according to the present disclosure.

[0054] In one particular embodiment, the polyurethane material is a rigid or flexible foam prepared by combining at least one isocyanate-functional group-containing compound and at least one active hydrogen-containing compound (such as a polyisocyanate and a polyol) in the presence of a piperazine-based tertiary amine catalyst of formula (1), optionally with one or more blowing agents and additives, to form a reaction mixture and subjecting the reaction mixture to conditions sufficient to react the polyol with the polyisocyanate. The polyisocyanate, polyol, piperazine-based tertiary amine catalyst, and optional blowing agent / additive(s) may be heated before mixing and forming the reaction mixture. In other embodiments, the polyisocyanate, polyol, piperazine-based tertiary amine catalyst, and optional blowing agent / additive(s) may be mixed at ambient temperature (e.g., about 15°C to 40°C), and heat may be applied to the reaction mixture, although in some embodiments, applying heat may not be necessary. Polyurethane foams can be made in a free-rise (slabstock) process, which allows the foam to grow freely with minimal or no vertical constraint. Alternatively, molded foams can be made by introducing a reaction mixture into a closed mold and allowing the reaction mixture to expand within the mold. The specific polyisocyanate and polyol are selected to provide the desired properties for the resulting foam. Other additives useful in making polyurethane foams, such as those listed above, can also be included to produce specific types of foam.

[0055] According to another embodiment, polyurethane materials can be produced in a one-step process in which an A-side reactant reacts with a B-side reactant. The A-side reactant can include a polyisocyanate, while the B-side reactant can include a polyol, a piperazine-based tertiary amine catalyst, and an optional blowing agent. In some embodiments, the A-side and / or B-side can also optionally contain one or more additives described above.

[0056] Polyurethane materials can be used in a variety of applications, such as precoats; backing materials for carpets; building composites; thermal insulation; spray foam insulation; applications requiring the use of impingement mix spray guns; urethane / urea hybrid elastomers; interior and exterior vehicle parts (such as bed liners, dashboards, door panels, and handles); flexible foams (such as furniture foams and vehicle part foams); integral skin foams; rigid spray foams; rigid pore-in-place foams; coatings; adhesives; sealants; filament winding; and other polyurethane composite, foam, elastomer, resin, and reaction injection molding (RIM) applications.

[0057] The present disclosure will now be further described with reference to the following non-limiting examples. [Example]

[0058] Example 1. Polycarbonate Staining Test / Amine Release Polycarbonate (PC) staining tests were conducted using apparatus 100, as generally shown in the figures. Apparatus 100 can include a container 106 (such as a glass container) with a removable lid 108 that can accommodate a second inverted container 110 (such as an inverted glass container or aluminum bridge) that can support polyurethane foam sample 102 so that the polyurethane foam sample 102 is maintained above water 112. A polycarbonate slab 104 can be suspended from the top of container 106 so that it is maintained a desired distance from polyurethane foam sample 102. For purposes of Example 1, polyurethane foam sample 102 was obtained using the ingredients set forth in Table 1. [Table 3]

[0059] The apparatus 100 was assembled so that the minimum distance between the polyurethane foam sample 102 and a polycarbonate slab (30 mm x 10 mm x ±3 mm) 104 was 2 cm. The apparatus 100 was then placed in an oven maintained at 90°C for 7 days. After the first 24 hours, the polyurethane foam sample 102 was observed to determine discoloration / clarity without opening the container 106. After 7 days, the polyurethane foam sample 102 was removed from the container 106 and examined for discoloration, clarity, cracking / splitting / expansion, and tackiness. Additionally, amine release from the polyurethane foam sample 102 was determined according to the VDA-28 test method described in U.S. Pat. No. 11,101,757, the contents of which are incorporated herein by reference. The results are shown in Table 2 below. [Table 4]

[0060] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, the scope of which is determined by the appended claims.

Claims

1. (i) Formula (1) 【Chemical 1】 A piperazine-based tertiary amine catalyst represented by: wherein n is an integer from 0 to about 25; and AO is -C ２ H ４ O-, -C ３ H ６ O- and -C ４ H ８ and R is an alkyl oxide independently selected from O— at each AO unit; ２ is methyl, ethyl, isopropyl, or —R ３ R ４ -X, where R ３ and R ４ is independently selected from methyl, ethyl, and isopropylamino groups, and X is a lower alkyl group optionally interrupted by an oxygen atom; (ii) a compound containing an isocyanate functional group; and (iii) an active hydrogen-containing compound; and A polyurethane formulation comprising:

2. 2. The polyurethane formulation of claim 1, wherein n is an integer from about 2 to about 10.

3. AO is -C ２ H ４ O- and -C ３ H ６ 10. The polyurethane formulation of claim 1, wherein each AO unit is independently selected from: O-.

4. AO in each AO unit is -C ３ H ６ 2. The polyurethane formulation of claim 1, wherein the hydroxyl group is O-.

5. 10. The polyurethane formulation of claim 1, wherein the polyurethane formulation further comprises an amine catalyst or a non-amine catalyst containing at least one tertiary amine group, or a mixture thereof.

6. The polyurethane formulation of claim 1 , wherein the polyurethane formulation further comprises one or more of a blowing agent and an additive.

7. 1. A catalyst package for use in forming a polyurethane material, comprising: (i) Formula (1) 【Chemistry 2】 A piperazine-based tertiary amine catalyst represented by: wherein n is an integer from 0 to about 25; and AO is -C ２ H ４ O-, -C ３ H ６ O- and -C ４ H ８ and R is an alkyl oxide independently selected from O— at each AO unit; ２ is methyl, ethyl, isopropyl, or —R ３ R ４ -X, where R ３ and R ４ is independently selected from methyl, ethyl, and isopropylamino groups, and X is a lower alkyl group optionally interrupted by an oxygen atom; (ii) a second component selected from an amine catalyst containing at least one tertiary amine group, a non-amine catalyst, a halogenated olefin compound, and mixtures thereof; The catalyst package comprising:

8. 8. The catalyst package of claim 7, wherein n is from about 2 to about 10.

9. AO in each AO unit is -C ３ H ６ The catalyst package of claim 8, wherein the cation is O-.

10. 1. A method for producing a polyurethane material, comprising: Formula (1) 【Chemistry 3】 Piperazine-based tertiary amines represented by wherein n is an integer from 0 to about 25; and AO is -C ２ H ４ O-, -C ３ H ６ O- and -C ４ H ８ and R is an alkyl oxide independently selected from O— at each AO unit; ２ is methyl, ethyl, isopropyl, or —R ３ R ４ -X, where R ３ and R ４ is independently selected from methyl, ethyl, and isopropylamino groups, and X is a lower alkyl group optionally interrupted by an oxygen atom, in the presence of the piperazine-based tertiary amine, comprising: contacting a compound containing an isocyanate functional group, an active hydrogen-containing compound, and optionally one or more of a blowing agent and an additive.

11. n is an integer from about 2 to about 10; R ２ The method of claim 10, wherein is methyl.

12. 11. A polyurethane material produced according to the method of claim 10.

13. 13. The polyurethane material of claim 12, wherein the polyurethane material is a rigid foam or a flexible foam.

14. 13. The polyurethane material produced according to the method of claim 12 for use as a precoat, a backing material for carpet, a building composite, thermal insulation, spray foam insulation, a urethane / urea hybrid elastomer, an interior vehicle part and an exterior vehicle part, a flexible foam, an integral skin foam, a rigid spray foam, a rigid pour-in-place foam, a coating, an adhesive, a sealant, or a filament winding.

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