Polyisocyanurate comprising foams with long cream time and snap-cure behaviour

Abstract

A reaction mixture and a process for making a polyisocyanurate comprising rigid foam having a density in the range 50-500 kg/m.sup.3 is disclosed, said process having a cream time >35 seconds and a snap cure behaviour.

Claims

1. A process for making a polyisocyanurate comprising rigid foam having a density in the range 50-500 kg/m.sup.3, said process having a cream time >35 seconds and a snap cure behaviour and comprising combining and mixing at an isocyanate index of at least 200 the following components: a polyisocyanate composition comprising one or more polyisocyanate compounds; a catalyst composition comprising at least a trimerization catalyst compound in an amount of at least 50 wt % based on the total weight of all catalyst compounds in the catalyst composition; an isocyanate-reactive composition comprising at least a low molecular weight (MW) polyol having a MW below 200 g/mol in an amount of 0.1 up to 30 wt % based on the total weight of the isocyanate-reactive composition; one or more blowing agents comprising at least 50 mol % water based on the total molar amount of all blowing agents; optionally one or more surfactants, one or more flame retardants, one or more antioxidants or combinations thereof; wherein the wt % of the trimerization catalyst compounds is <0.5 wt % based on the total weight of the trimerization catalyst compounds and the polyisocyanate composition.

2. The process according to claim 1, wherein the cream time is >45 seconds.

3. The process according to claim 1, wherein the isocyanate index is higher than 220.

4. The process according to claim 1, wherein the wt % of the trimerization catalyst compounds is preferably <0.45 wt % based on the total weight of the trimerization catalyst compounds and the polyisocyanate composition.

5. The process according to claim 1, wherein the wt % of the trimerization catalyst compounds is <0.30 wt % based on the total weight of the trimerization catalyst compounds and the polyisocyanate composition.

Description

DETAILED DESCRIPTION

(1) The present invention will be described with respect to particular embodiments. 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.

(2) 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.

(3) 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.

(4) The present invention relates to a reaction system such that both a long cream time (>35 seconds) and a rapid cure (snap cure behaviour) are achieved. The invention further relates to a process for making polyisocyanurate comprising foams, more particularly for making polyisocyanurate comprising rigid foams for use in composite materials such as honeycomb structures thereby using the reaction system of the current invention.

(5) According to a first aspect of the invention, a reaction system for making a polyisocyanurate comprising foam having a free rise density in the range 50-500 kg/m.sup.3 (measured according to ISO 845) is disclosed. Said reaction system comprising at least: a polyisocyanate composition comprising one or more polyisocyanate compounds; a catalyst composition comprising at least a trimerization catalyst compound in an amount of at least 50 wt % based on the total weight of all catalyst compounds in the catalyst composition; an isocyanate reactive composition comprising at least a low molecular weight (MW) polyol having a MW below 200 g/mol in an amount of 0.1 up to 30 wt % based on the total weight of the isocyanate-reactive composition; one or more blowing agents comprising at least 50 mol % water based on the total molar amount of blowing agents; optionally providing one or more surfactants, one or more flame retardants, one or more antioxidants or combinations thereof; wherein the wt % of the trimerization catalyst compounds is <0.5 wt % based on the total weight of the catalyst composition+polyisocyanate composition.

(6) According to embodiments, the wt % of the trimerization catalyst compounds is <0.5 wt %, preferably <0.45 wt %, more preferred <0.4 wt %, most preferred <0.35 wt % based on the total weight of the catalyst composition+polyisocyanate composition.

(7) According to embodiments, the wt % of the trimerization catalyst compounds is <0.30 wt % based on the total weight of the catalyst composition+polyisocyanate composition.

(8) According to embodiments, the low molecular weight (MW) polyol has a molecular weight below 200 g/mol, preferably below 150 g/mol, more preferably below 100 g/mol.

(9) An advantage of the reaction mixture of the present invention is that it can be used to achieve both a long cream time and a short curing time involving polyisocyanurate (PIR) formation. This combined effect leads to a reduced production cycle time, for instance in composite applications.

(10) According to embodiments, the catalyst composition comprises at least a trimerization catalyst compound in an amount of at least 75 wt %, more preferably in an amount of at least 90 wt % based on the total weight of all catalyst compounds in the catalyst composition.

(11) According to a preferred embodiment of the first aspect of the invention, the trimerization catalyst is selected from organic salts, preferably from alkali metal, earth alkali metal and/or quaternary ammonium organic salts. More preferably said organic salt is selected from carboxylates or alkoxides and mixtures thereof, the carboxylate/alkoxide group preferably having 1-12 carbon atoms and mixtures thereof. Preferred examples are potassium carboxylates, sodium carboxylates, potassium alkoxides and sodium alkoxides. Also carboxylates/alkoxides having ring structures such as sodium or potassium benzoate are suitable trimerization catalysts. Most preferred examples are potassium acetate, potassium hexanoate, potassium ethylhexanoate, potassium octanoate, potassium lactate, N-hydroxypropyl trimethyl ammonium octanoate, N-hydroxypropyl trimethyl ammonium formate and mixtures thereof. Suitable catalysts are commercially available; examples are Catalyst LB from Huntsman or Dabco® K2097 from Air Products (comprising potassium acetate), and Dabco® K15 (comprising potassium octoate).

(12) According to embodiments, the low molecular weight (MW) polyol having a MW below 200 g/mol is present in the reaction mixture in an amount of 0.1 up to 30 wt %, preferably 1 up to 25 wt %, more preferably 2 up to 20 wt % based on the total weight of the isocyanate-reactive composition.

(13) According to embodiments, the one or more isocyanate reactive compounds having low molecular weight are selected from monools and/or polyols such as glycols. Suitable examples are monools selected from methanol, ethanol, propanol, butanol, phenol, cyclohexanol and hydrocarbon monools having a number average molecular weight up to 200 g/mol like aliphatic and polyether monools and/or polyols selected from monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, trimethylol propane, sorbitol, glycerol, propanediol, butanediol, pentanediol, hexanediol, aromatic and/or aliphatic polyols having a molecular weight <200, preferably <150 g/mol, more preferably <100 g/mol.

(14) According to embodiments, the isocyanate reactive composition further comprises beside the low MW polyol a high molecular weight polyol having a number average molecular weight of preferably 200-8000 and an average nominal functionality of preferably 1-8. Said high molecular weight polyol may be selected from polyether polyols, polyester polyols, mercaptans, carboxylic acids such as polybasic acids, amines, polyamines having an average nominal hydroxy functionality of 1-8 and a number average molecular weight of up to 8000 and mixtures thereof. Examples of suitable polyols are Hoopol® F-1390 (a polyester polyol from Synthesia) and Daltolac® R-166 (a polyether polyol from Huntsman).

(15) According to a second aspect of the invention, a process for making a polyisocyanurate comprising foam is disclosed thereby using the reaction mixture of the invention. Said process therefore comprises combining and mixing the ingredients of the reaction mixture at an isocyanate index of at least more than 200, preferably an isocyanate index of 220 or higher.

(16) According to embodiments, the process for making a polyisocyanurate comprising foam according to the invention leads both to a cream time >35 seconds, preferably >45 seconds, more preferably >55 seconds and a snap cure behaviour <110 seconds, preferably <90 seconds, more preferably <70 seconds.

(17) There are many different orders of contacting or combining the compounds required to make the polyisocyanurate comprising foam of the present invention. One of skill in the art would realize that varying the order of addition of the compounds falls within the scope of the present invention.

(18) According to embodiments, the polyisocyanate compounds used in the reaction mixture for making a PIR comprising foam according to the invention are selected from organic isocyanates containing a plurality of isocyanate groups including aliphatic isocyanates such as hexamethylene diisocyanate and more preferably aromatic isocyanates such as m- and p-phenylene diisocyanate, tolylene-2,4- and 2,6-diisocyanates, diphenylmethane-4,4′-diisocyanate, chlorophenylene-2,4-diisocyanate, naphthylene-1,5-diisocyanate, diphenylene-4,4′-diisocyanate, 4,4′-diisocyanate-3,3′-dimethyldiphenyl, 3-methyldiphenylmethane-4,4′-diisocyanate and diphenyl ether diisocyanate, cycloaliphatic diisocyanates such as cyclohexane-2,4- and 2,3-diisocyanates, 1-methyl cyclohexyl-2,4- and 2,6-diisocyanates and mixtures thereof and bis-(isocyanatocyclohexyl-)methane and triisocyanates such as 2,4,6-triisocyanatotoluene and 2,4,4′-triisocyanatodiphenyl ether.

(19) According to embodiments, the polyisocyanate composition comprises mixtures of polyisocyanates. For example a mixture of tolylene diisocyanate isomers such as the commercially available mixtures of 2,4- and 2,6-isomers and also the mixture of di- and higher poly-isocyanates produced by phosgenation of aniline/formaldehyde condensates. Such mixtures are well-known in the art and include the crude phosgenation products containing mixtures of methylene bridged polyphenyl polyisocyanates, including diisocyanate, triisocyanate and higher polyisocyanates together with any phosgenation by-products.

(20) Preferred polyisocyanate compositions of the present invention are those wherein the polyisocyanate is an aromatic diisocyanate or polyisocyanate of higher functionality in particular crude mixtures of methylene bridged polyphenyl polyisocyanates containing diisocyanates, triisocyanate and higher functionality polyisocyanates. Methylene bridged polyphenyl polyisocyanates (e.g. Methylene diphenyl diisocyanate, abbreviated as MDI) are well known in the art and have the generic formula I wherein n is one or more and in the case of the crude mixtures represents an average of more than one. They are prepared by phosgenation of corresponding mixtures of polyamines obtained by condensation of aniline and formaldehyde.

(21) ##STR00001##

(22) Other suitable polyisocyanate compositions may include isocyanate ended prepolymers made by reaction of an excess of a diisocyanate or higher functionality polyisocyanate with a hydroxyl ended polyester or hydroxyl ended polyether and products obtained by reacting an excess of diisocyanate or higher functionality polyisocyanate with a monomeric polyol or mixture of monomeric polyols such as ethylene glycol, trimethylol propane or butane-diol. One preferred class of isocyanate-ended prepolymers are the isocyanate ended prepolymers of the crude mixtures of methylene bridged polyphenyl polyisocyanates containing diisocyanates, triisocyanates and higher functionality polyisocyanates.

(23) According to embodiments, the polyisocyanate compounds in the polyisocyanate composition are selected from a toluene diisocyanate, a methylene diphenyl diisocyanate or a polyisocyanate composition comprising a methylene diphenyl diisocyanate or a mixture of such polyisocyanates.

(24) According to embodiments, the isocyanate index is higher than 200, preferably higher than 220, more preferably higher than 250. For example the isocyanate index may range from 200 to 1000, from 200 to 600, or from 200 to 400.

(25) Using reaction mixtures having isocyanate index >200 (leading to isocyanurate formulations) in e.g. composite honeycomb applications provides several advantages over reaction mixtures having isocyanate index around 100 (leading to polyurethane formulations). For instance, the exotherm released is typically higher which results in lower mould temperatures necessary to achieve resin curing (i.e. energy savings), the high aromatic content of reaction mixtures having isocyanate index >200 provides the final composites better fire properties, and the high crosslink density results in enhanced mechanical properties (higher Tg, . . . ).

(26) According to embodiments, the blowing agent is preferably water used alone or in combination with alternative blowing agents. Alternative blowing agent may be selected from isobutene, dimethyl ether, methylene chloride, acetone, chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), hydrofluoroolefins (HFOs) and hydrocarbons such as pentane. The amount of blowing agent used can vary based on, for example, the intended use and application of the foam product and the desired foam stiffness and density. The blowing agent may be present in amounts from 0.1 to 80 parts by weight (pbw) per hundred weight parts isocyanate reactive compounds (polyol) including the weight contribution of the catalyst composition, more preferably from 0.2 to 60 pbw.

(27) According to embodiments, one or more urethane catalyst compounds may be added to the reaction mixture if needed although a trimerisation catalyst compound should be present in an amount of >50 wt % based on the total weight of all catalyst compounds used. Urethane catalysts suitable for use herein include, but are not limited to, metal salt catalysts, such as organotins, and amine compounds, such as triethylenediamine (TEDA), N-methylimidazole, 1,2-dimethylimidazole, N-methylmorpholine, N-ethylmorpholine, triethylamine, N,N′-dimethylpiperazine, 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine, 2,4,6-tris(dimethylaminomethyl)phenol, N-methyldicyclohexylamine, pentamethyldipropylene triamine, N-methyl-N′-(2-dimethylamino)-ethyl-piperazine, tributylamine, pentamethyldiethylenetriamine, hexamethyltriethylenetetramine, heptamethyltetraethylenepentamine, dimethylaminocyclohexylamine, pentamethyldipropylene-triamine, triethanolamine, dimethylethanolamine, bis(dimethylaminoethyl)ether, tris(3-dimethylamino)propylamine, or its acid blocked derivatives, and the like, as well as any mixture thereof.

(28) The present invention further relates to a polyisocyanurate comprising foam made using the process according to the invention and making use of the reaction mixture disclosed in the present invention and the use of said foam in e.g. composite materials such as fiber reinforced honeycomb composite structures for fast cycle automotive applications (parcel shelves, load floors, headliners, trays, semi structural components . . . ).

(29) According to embodiments, the polyisocyanurate comprising material according to the invention has a free rise density (measured according to ISO 845) in the range between 50 kg/m.sup.3 up to 500 kg/m.sup.3, preferably in the range 75 kg/m.sup.3 up to 300 kg/m.sup.3, more preferably in the range 100 kg/m.sup.3 up to 200 kg/m.sup.3.

(30) According to preferred embodiments, a composite material having composite honeycomb structures with a core layer comprising the polyisocyanurate comprising material made according to the invention is disclosed.

(31) According to embodiments, the reaction mixture of the instant invention may be applied by means of spraying after the required ingredients were mixed at the departure point from a spray nozzle onto e.g. a honeycomb structure or into a mold.

(32) According to embodiments, the polyisocyanurate comprising foam of the instant invention may be used in e.g. honeycomb structures. The polyisocyanurate comprising foam of the instant invention fulfills all the requirements to allow sufficient time for the reaction mixture to be sprayed homogeneously on a substrate such as e.g. a glass fiber or honeycomb assembly and/or to insert it inside a heated compression mould where curing is then performed, while a snap-cure behaviour is preferred to minimize cycle time.

EXAMPLES

(33) Chemicals used: Hoopol® F-1390: Polyester polyol from Synthesia (OH value: 240 mgKOH/g) Daltolac® R-166: Polyether polyol from Huntsman (OH value: 165 mgKOH/g) Tegostab® B8490: Silicon surfactant from Evonik (OH value: 0 mgKOH/g) LB Catalyst: Potassium acetate PIR catalyst from Huntsman (OH value: 865 mgKOH/g, 48.2 wt % potassium acetate, 48.2 wt % MEG, 3.6 wt % water) DETDA: DiEthylTolueneDiAmine from Lonza (OH value: 630 mgKOH/g), used as chain extender DABCO® 33LV: Gelling catalyst from Air Products (OH value: 560 mgKOH/g, 33 wt % TEDA TriethyleneDiAmine in dipropylene glycol) Jeffcat PMDETA: PentaMethylDiethyleneTriAmine, blowing catalyst from Huntsman (OH value: 0 mgKOH/g) Glycerol: from Huntsman (OH value: 1826 mgKOH/g) MEG: MonoEthylene Glycol from Sigma-Aldrich (OH value: 1808 mgKOH/g) Black Repitan 90655: carbon black dispersion in polyether polyol from REPI (OH value: 30 mgKOH/g) IMR VP063235: Internal mould release from KVS Eckert & Woelk S2085: Suprasec® 2085 from Huntsman (Polymeric MDI, NCO value: 30.5) S5025: Suprasec® 5025 from Huntsman (Polymeric MDI, NCO value: 31.0)

(34) Suprasec® and Daltolac® are trademarks of the Huntsman Corporation or an Affiliate thereof and have been registered in one or more but not all countries.

Examples 1-7 and Comparative Examples 1-2

(35) All foams were produced under free rise conditions in cup scale (˜120 g) by mixing under high shear with a Heidolph Mixer (˜4000 rpm) for 10 seconds the polyol blend (prepared beforehand) and the Isocyanate. Foam density was measured according to standard test method ISO845.

(36) Table 1 summarizes the amounts of ingredients used in pbw (parts by weight) to fabricate foams according to the present invention (examples 1-7) and to fabricate comparative foams (comparative examples 1-2).

(37) Compared to comparative example 1 (no low MW polyol present), Examples 1 and 2 evidence that the presence of increasing amounts of glycerol both delays cream time (55 seconds.fwdarw.65 seconds.fwdarw.70 seconds) and improves the snap cure behaviour with a decreased Δt (45 seconds.fwdarw.40 seconds.fwdarw.40 seconds). In other words, the snap cure behaviour is improved in the presence of glycerol while not decreasing cream time (i.e. keeping a long cream time).

(38) A similar trend is observed looking at comparative example 2 and examples 4, 5, 6 and 7 which contain increasing amounts of MEG (CT: 47 seconds.fwdarw.67 seconds.fwdarw.82 seconds.fwdarw.87 seconds.fwdarw.112 seconds; Δt: 103 seconds.fwdarw.83 seconds.fwdarw.58 seconds.fwdarw.28 seconds.fwdarw.28 seconds). The presence of MEG improves the snap cure behaviour while not decreasing cream time.

(39) Comparing example 3 and comparative example 1 evidences that increasing both the amount of PR catalyst and low Mw polyol (glycerol in this specific case) can allow to keep a constant cream time (55 seconds in this specific case, i.e. not decreased) while improving dramatically the snap cure behaviour (Δt drops from 45 seconds to 25 seconds).

(40) All these examples therefore evidence that the presence of both PR catalyst and low Mw polyol allows to keep a long cream time (>35 seconds) and to improve the snap-cure behaviour (decreased Δt).

(41) TABLE-US-00001 TABLE 1 Chemical Comp Comp (pbw) Ex. 1 Ex.1 Ex.2 Ex.3 Ex. 2 Ex.4 Ex.5 Ex.6 Ex.7 Hoopol 98.23 98.23 98.23 98.23 52.2 52.2 52.2 52.2 52.2 F-1390 Water 1 1 1 1 1 1 1 1 1 Tegostab 1.77 1.77 1.77 1.77 1.77 1.77 1.77 1.77 1.77 B 8490 LB Catalyst 1 1 1 1.25 1 1 1 1 1 DETDA 4 4 4 4 4 4 4 4 4 Glycerol — 2 3 3 — — — — — MEG — — — — — 2 5 10 15 Black — — — — 4 4 4 4 4 Repitan 90655 IMR — — — — 7.5 7.5 7.5 7.5 7.5 VP063235 S2085 231.47 231.47 231.47 231.47 — — — — — S5025 — — — — 270 270 270 270 270 wt % 100 100 100 100 100 100 100 100 100 trimerization catalyst compound(s) towards all catalyst compounds (*) wt % 0.208 0.208 0.208 0.260 0.178 0.178 0.178 0.178 0.178 trimerization catalyst compounds towards Iso (**) Iso Index 284 256 244 243 502 432 357 277 226 Density 122.4 131.8 130.7 136 136 131.2 127.5 96.6 122.4 (kg/m.sup.3) Cream Time 55 65 70 55 47 67 82 87 112 (s) Tack Free 100 105 110 80 150 150 140 115 140 Time (s) EoR (s) 130 140 143 120 285 230 205 170 160 Δt (s) 45 40 40 25 103 83 58 28 28 (TFT-CT) (*) Amount (wt %) of trimerization catalyst compounds based on the total weight of all catalyst compounds. (**) Amount (wt %) of trimerization catalyst compounds based on the total weight of all trimerization catalyst compounds + isocyanate compounds.

Examples 8-14 and Comparative Examples 3-4

(42) Similar foam production method was used as for examples 1-7 and comparative examples 1-2.

(43) Table 2 summarizes the amounts of ingredients used in pbw (parts by weight) to fabricate foams according to the present invention (examples 8-14) and to fabricate comparative foams (comparative examples 3-4).

(44) Comparative examples 3 and 4 evidence that although the snap-cure behaviour is improved (decreased Δt from 365 seconds to 166 seconds) when increasing the amount of PR catalyst, in the absence of low MW polyol cream time (CT) is also significantly decreased (55 seconds towards 32 seconds), which is not desired. In Example 11, the presence of glycerol and a higher amount of PIR catalyst allows to achieve a similar CT (58 seconds) as Comparative Example 3 (55 seconds) while achieving a much faster cure (Δt=57 seconds versus 365 seconds).

(45) Compared to comparative example 4 (no low MW polyol present), examples 8, 9, 10, 11 and 12 evidence that the presence of increasing amounts of glycerol both delays cream time (32 seconds.fwdarw.38 seconds.fwdarw.42 seconds.fwdarw.48 seconds.fwdarw.58 seconds.fwdarw.65 seconds) and improves the snap cure behaviour with a decreased Δt (166 seconds.fwdarw.107 seconds.fwdarw.73 seconds.fwdarw.52 seconds.fwdarw.57 seconds.fwdarw.50 seconds). In other words, the snap cure behaviour is improved in the presence of glycerol while not decreasing cream time (i.e. keeping a long cream time).

(46) A similar trend is observed looking at comparative example 4 and examples 13 and 14, which contain increasing amounts of MEG (Cream Time: 32 seconds.fwdarw.40 seconds.fwdarw.45 seconds; Δt: 166 seconds.fwdarw.40 seconds.fwdarw.20 seconds). The presence of MEG improves the snap cure behaviour while not decreasing cream time.

(47) All these examples therefore evidence that the presence of both PIR catalyst and low MW polyol allows to keep a long cream time (>35 seconds) and to improve the snap-cure behaviour (decreased Δt).

(48) Using polyesters (e.g. Hoopol® F-1390) or polyethers (e.g Daltolac® R 166) does not influence the trends of the effect of PIR catalyst and/or low MW polyol on foaming kinetics and snap-curing behaviour.

(49) TABLE-US-00002 TABLE 2 Comp Comp Chemical (pbw) ex. 3 Ex. 4 Ex. 8 Ex. 9 Ex. 10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Daltolac 72.2 72.2 72.2 72.2 72.2 72.2 72.2 72.2 72.2 R 166 Water 1 1 1 1 1 1 1 1 1 Tegostab 1.77 1.77 1.77 1.77 1.77 1.77 1.77 1.77 1.77 B 8490 LB Catalyst 0.3 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 DETDA 4 4 4 4 4 4 4 4 4 Glycerol — — 2 5 7.5 9 10 — — MEG — — — — — — — 10 15 Black Repitan 4 4 4 4 4 4 4 4 4 90655 IMR VP063235 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 S5025 250 250 250 250 250 250 250 250 250 Iso Index 492 488 416 341 297 275 262 263 212 wt % trimerization 100 100 100 100 100 100 100 100 100 catalyst compound(s) towards all catalyst compounds (*) wt % trimerization 0.058 0.096 0.096 0.096 0.096 0.096 0.096 0.096 0.096 catalyst compounds towards Iso (**) Density (kg/m.sup.3) 160.4 140.6 132.3 106.1 106.5 112.2 98.3 103.5 93.2 Cream Time (s) 55 32 38 42 48 58 65 40 45 Tack FreeTime (s) 420 198 145 115 100 115 115 80 65 EoR (s) 360 270 175 160 130 145 150 105 85 Δt (s) 365 166 107 73 52 57 50 40 20 (TFT-CT) (*) Amount (wt %) of trimerization catalyst compounds based on the total weight of all catalyst compounds. (**) Amount (wt %) of trimerization catalyst compounds based on the total weight of all trimerization catalyst compounds + isocyanate compounds.

Example 10 and Comparative Examples 5-10

(50) Similar foam production method was used as for examples 1-7 and comparative examples 1-2.

(51) Table 3 summarizes the amounts of ingredients used in pbw (parts by weight) to fabricate foams according to the present invention (example 10) and to fabricate comparative foams (comparative examples 5-10).

(52) Example 10 is the same example as illustrated in Table 2.

(53) Compared to Example 10, comparative examples 5, 6, 7, 8, 9 and 10 evidence that the presence of large amounts of polyurethane gelling and blowing catalysts decreases cream time significantly below 35 seconds while even deteriorating the snap-cure behaviour (comparative examples 6, 7, 9 and 10).

(54) TABLE-US-00003 TABLE 3 Comp Comp Comp Comp Comp Comp Chemical (pbw) Ex. 10 ex. 5 ex. 6 ex. 7 ex. 8 ex. 9 ex. 10 Daltolac R 166 72.2 72.2 72.2 72.2 72.2 72.2 72.2 Water 1 1 1 1 1 1 1 Tegostab B 8490 1.77 1.77 1.77 1.77 1.77 1.77 1.77 DETDA 4 4 4 4 4 4 4 LB Catalyst 0.5 0.5 0.17 0.08 0.5 0.17 0.08 Glycerol 7.5 7.5 2.5 1.25 7.5 2.5 1.25 PMDETA — 0.2 0.07 0.03 0.2 0.07 0.03 33LV — 1.5 0.5 0.25 4.5 1.5 0.75 Black Repitan 90655 4 4 4 4 4 4 4 IMR VP063235 7.5 7.5 7.5 7.5 7.5 7.5 7.5 wt % trimerization 100 25.7 25.9 25.2 12.5 12.7 12.0 catalyst compound(s) towards all catalyst compounds (*) S5025 250 250 250 250 250 250 250 Wt % trimerization 0.096 0.096 0.033 0.015 0.096 0.033 0.015 catalyst compounds towards Iso (**) Iso Index 297 290 402 445 277 393 439 Density (kg/m.sup.3) 106.5 147.4 180.7 234.3 150.8 168.3 174.2 CT (s) 48 9 15 22 7 12 19 TFT (s) 100 60 840 2400 45 360 1200 EoR (s) 130 37 115 215 35 70 140 Δt (s) (TFT-CT) 52 51 825 2378 38 348 1181 (*) Amount (wt %) of trimerization catalyst compounds based on the total weight of all catalyst compounds. (**) Amount (wt %) of trimerization catalyst compounds based on the total weight of all trimerization catalyst compounds + isocyanate compounds.

Example 3 and Comparative Examples 11-13

(55) Similar foam production method was used as for examples 1-7 and comparative examples 1-2.

(56) Table 4 summarizes the amounts of ingredients used in pbw (parts by weight) to fabricate a foam according to the present invention (example 3) and to fabricate comparative foams (comparative examples 11, 12 and 13).

(57) Example 3 is the same example as illustrated in Table 1.

(58) Compared to Example 3, Comparative examples 11, 12 and 13 evidence that if the amount of PIR catalyst is too high (i.e. >0.5 wt %), despite the presence of glycerol, cream time is decreased significantly down to values below 35 s.

(59) TABLE-US-00004 TABLE 4 Chemical Comp Comp Comp (pbw) Ex. 3 Ex. 11 Ex. 12 Ex. 13 Hoopol 98.23 98.23 98.23 98.23 F-1390 Water 1 1 1 1 Tegostab 1.77 1.77 1.77 1.77 B 8490 LB Catalyst 1.25 2.5 3.0 3.5 DETDA 4 4 4 4 Glycerol 3 3 3 3 S2085 231.47 231.47 231.47 231.47 wt % 100 100 100 100 trimerization catalyst compound (s) towards all catalyst compounds (*) wt % 0.260 0.518 0.621 0.724 trimerization catalyst compounds towards Iso (**) Iso Index 243 236 233 231 Density 136 109 104 104 (kg/m.sup.3) Cream 55 33 30 25 Time (s) Tack Free 80 45 40 30 Time (s)  EoR (s) 120 70 55 50  .sub. Δt (s) 25 12 10 5 (TFT-CT) (*) Amount (wt %) of trimerization catalyst compounds based on the total weight of all catalyst compounds. (**) Amount (wt %) of trimerization catalyst compounds based on the total weight of all trimerization catalyst compounds + isocyanate compounds.