High-resiliency polyurethane foam and method of making

Abstract

High resiliency polyurethane foams are made by reacting a polyisocyanate with a mixture of polyols and water. The polyols include a cell opener. The cell opener is a random copolymer of 60 to 80 wt.-% ethylene oxide and correspondingly 40 to 20 wt.-% propylene oxide having a nominal functionality of 2 to 4 and a hydroxyl number of 25 to 50, wherein 50 to 75% of the hydroxyl groups of polyether polyol are primary hydroxyl groups, which is made using a modified double metal cyanide catalyst.

Description

This invention relates to polyurethane foams having high resiliency properties.High-resiliency polyurethane foams are used extensively in cushioning applications such as seating. These foams are characterized in having good load-bearing properties and support factors, to provide high cushioning comfort and dynamic fatigue performance. High-resiliency foam also recovers its original dimensions rapidly when a compressive force applied to the foam is released.These foams can be made from a foam formulation that includes as a main component a high equivalent weight, highly reactive polyether polyol. A so-called “polymer polyol”, that contains dispersed polymer particles, is typically present to enhance load-bearing. Foam formulations based on this combination of polyols tend to have many closed cells, so a cell opener is usually present in the foam formulation as well. One class of cell openers includes random copolymers of ethylene oxide and propylene oxide that have a high content of polymerized ethylene oxide (50 to 80% of the total weight of the copolymer) and a high proportion of primary hydroxyl groups.This random copolymer can be made by polymerizing a mixture of ethylene oxide and propylene oxide in the presence of a starter that contains 2 to 4, preferably 3, hydroxyl groups, using potassium hydroxide as a polymerization catalyst. This polymerization process has well-known disadvantages. Monofunctional impurities can form due to the isomerization of propylene oxide to propenyl alcohol and subsequent alkoxylation of that propenyl alcohol. In addition, neutralization and complete removal of catalyst residues is necessary. This requires additional finishing operations that add significant production time and costs.So-called DMC (double metal cyanide) catalyst complexes are alternatives to potassium hydroxide as polymerization catalysts. Polyether polyols made using DMC catalysts do not require catalyst neutralization and removal. Random ethylene oxide / propylene oxide copolymers having high contents of polymerized ethylene oxide made in a continuous process using DMC catalysts are described, for example, in WO 2019 / 055177. In an example, a viscoelastic polyurethane foam is made with such a polyol. That foam is not suitable for most seating applications because of inadequate load-bearing and long recovery times after being compressed. Unfortunately, however, the random copolymer of WO 2019 / 055177 have not been used successfully as a cell opener in high resiliency foam. The presence of these random copolymers in amounts typically required to provide cell opening instead results in collapse of the foam. Even very small quantities of the random copolymers of WO 2019 / 055177 results in degradation of some foam properties.WO 2018 / 209069 and WO 2018 / 209075 disclose catalyst compositions made by precipitating a catalyst in the presence of certain metal compounds, which may include gallium, hafnium, indium or aluminum compounds.The invention in one aspect is a method of making a polyurethane foam, comprising I) forming a reaction mixture comprising:A) a polyol mixture comprising(A-1) 80 to 99 weight percent, based on the total weight of the polyol mixture (A), of one or more polyether polyols having a nominal functionality of 2 to 4, a hydroxyl number of 18 to 50 mg KOH / g, and an oxyethylene content of at most 35% by weight, wherein at least 30% of the weight of the one or more polyether polyols (A-1) is an ethylene oxide-capped poly(propylene oxide) and wherein at least a portion of the one or more polyether polyols (A-1 contains dispersed solid polymer particles;(A-2) 1 to 10 weight percent, based on the total weight of the polyol mixture (A), of a polyether polyol having a nominal functionality of 2 to 4 and a hydroxyl number of 25 to 50, wherein 50 to 75% of the hydroxyl groups of polyether polyol (A-2) are primary hydroxyl groups, polyether polyol (A-2) being produced by copolymerizing an oxide mixture comprising 60 to 80 wt.-%, based on the weight of the oxide mixture of ethylene oxide and correspondingly 40 to 20 wt.-%, based on the weight of the oxide mixture of propylene oxide in the presence of an alkylene oxide polymerization catalyst corresponding to the formula:M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y • pM³wA²z (I)wherein:M¹ and M⁴ each represent a metal ion independently selected from Zn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Mo⁴⁺, Mo⁶⁺, Al³⁺, V⁴⁺, V⁵⁺, Sr²⁺, W⁴⁺, W⁶⁺, Mn²⁺, Sn²⁺, Sn⁴⁺, Pb²⁺, Cu²⁺, La³⁺, and Cr³⁺;M² and M⁵ each represent a metal ion independently selected from Fe³⁺, Fe²⁺, Co³⁺, Co²⁺, Cr²⁺, Cr³⁺, Mn²⁺, Mn³⁺, Ir³⁺, Ni²⁺, Rh³⁺, Ru²⁺, V⁴⁺, V⁵⁺, Ni²⁺, Pd²⁺, and Pt²⁺;M³ represents at least one magnesium, Group 3 – Group 15 metal, or lanthanide series metal or semi-metal ion;X¹ represents a group other than cyanide that is coordinated with the M² ion;X² represents a group other than cyanide that is coordinated with the M⁵ ion;A¹ represents a halide, nitrate, sulfate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, perchlorate, isothiocyanate, an alkanesulfonate, an arylenesulfonate, trifluoromethanesulfonate, or a C₁₋₄ carboxylate;A² represents least one alkoxide, aryloxy, carboxylate, acyl, pyrophosphate, phosphate, thiophosphate, dithiophosphate, phosphate ester, thiophosphate ester, amide, oxide, siloxide, hydride, carbamate, or hydrocarbon anion;b, c and d are each numbers that reflect an electrostatically neutral complex, provided that b and c each are greater than zero;x and y are integers that balance the charges in the metal salt M³xA¹y;r is an integer from 4 to 6;t is an integer from 0 to 2;n is a number from 0 and 20;p is a number from 0.002 to 10; andw and z are integers that balance the charges in the metal salt M³zA²z, provided that w is from 1 to 4; and(A-3) 0 to 10 weight percent, based on the total weight of the polyol mixture (A), of one or more additional polyols, different from polyether polyols (A-1) and (A-2), having number average molecular weights greater than 250 g / mol;B) 1 to 6 parts by weight water per 100 parts by weight of the polyol mixture (A);C) 1 to 5 parts by weight, per 100 parts by weight of the polyol mixture (A), of a crosslinker having 3 to 8 isocyanate-reactive groups per molecule and a formula molecular weight of up to 250 g / mol;D) a silicone surfactant;E) a catalytically effective amount of at least one urethane catalyst; andF) a polyisocyanate in an amount sufficient to produce an isocyanate index of 90 to 125, and(II) curing the reaction mixture to produce the polyurethane foam.In a second aspect the invention is a method of making a polyurethane foam, comprising I) forming a reaction mixture comprising:A) a polyol mixture comprising(A-1) 80 to 99 weight percent, based on the total weight of the polyol mixture (A), of one or more polyether polyols having a nominal functionality of 2 to 4, a hydroxyl number of 18 to 50 mg KOH / g, and an oxyethylene content of at most 35% by weight, wherein at least 30% of the weight of the one or more polyether polyols (A-1) is an ethylene oxide-capped poly(propylene oxide) and wherein at least a portion of the one or more polyether polyols (A-1 contains dispersed solid polymer particles;(A-2) 1 to 10 weight percent, based on the total weight of the polyol mixture (A), of a polyether polyol which is a random copolymer of 60 to 80 wt.-% ethylene oxide and correspondingly 40 to 20 wt.-% propylene oxide having a nominal functionality of 2 to 4 and a hydroxyl number of 25 to 50, wherein 50 to 75% of the hydroxyl groups of polyether polyol A-2) are primary hydroxyls, wherein polyether polyol (A-2) contains residues of an alkylene oxide polymerization catalyst corresponding to the formula:M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y • pM³wA²z (I)wherein:M¹ and M⁴ each represent a metal ion independently selected from Zn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Mo⁴⁺, Mo⁶⁺, Al³⁺, V⁴⁺, V⁵⁺, Sr²⁺, W⁴⁺, W⁶⁺, Mn²⁺, Sn²⁺, Sn⁴⁺, Pb²⁺, Cu²⁺, La³⁺, and Cr³⁺;M² and M⁵ each represent a metal ion independently selected from Fe³⁺, Fe²⁺, Co³⁺, Co²⁺, Cr²⁺, Cr³⁺, Mn²⁺, Mn³⁺, Ir³⁺, Ni²⁺, Rh³⁺, Ru²⁺, V⁴⁺, V⁵⁺, Ni²⁺, Pd²⁺, and Pt²⁺;M³ represents at least one magnesium, Group 3 - Group 15 metal, or lanthanide series metal or semi-metal ion;X¹ represents a group other than cyanide that is coordinated with the M² ion;X² represents a group other than cyanide that is coordinated with the M⁵ ion;A¹ represents a halide, nitrate, sulfate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, perchlorate, isothiocyanate, an alkanesulfonate, an arylenesulfonate, trifluoromethanesulfonate, or a C₁₋₄ carboxylate;A² represents least one alkoxide, aryloxy, carboxylate, acyl, pyrophosphate, phosphate, thiophosphate, dithiophosphate, phosphate ester, thiophosphate ester, amide, oxide, siloxide, hydride, carbamate, or hydrocarbon anion;b, c and d are each numbers that reflect an electrostatically neutral complex, provided that b and c each are greater than zero;x and y are integers that balance the charges in the metal salt M³xA¹y;r is an integer from 4 to 6;t is an integer from 0 to 2;n is a number from 0 and 20;p is a number from 0.002 to 10; andw and z are integers that balance the charges in the metal salt M³zA²z, provided that w is from 1 to 4; and(A-3) 0 to 10 weight percent, based on the total weight of the polyol mixture (A), of one or more additional polyols, different from polyether polyols (A-1) and (A-2), having number average molecular weights greater than 250 g / mol;B) 1 to 6 parts by weight water per 100 parts by weight of A);C) 1 to 5 parts by weight, per 100 parts by weight of A, of a crosslinker having 3 to 8 isocyanate-reactive groups per molecule and a formula molecular weight of up to 250 g / mol;D) a silicone surfactant;E) a catalytically effective amount of at least one urethane catalyst; andF) a polyisocyanate in an amount sufficient to produce an isocyanate index of 90 to 125, and(II) curing the reaction mixture to produce the polyurethane foam.The invention in a third aspect is a method of making a polyurethane foam, comprisingI) producing a polyether polyol having a nominal functionality of 2 to 4 and a hydroxyl number of 25 to 50, wherein 50 to 75% of the hydroxyl groups of polyether polyol A-3) are primary hydroxyls, by copolymerizing an oxide mixture comprising 60 to 80 wt.-%, based on the weight of the oxide mixture, of ethylene oxide and correspondingly 40 to 20 wt.-%, based on the weight of the oxide mixture, of propylene oxide in the presence of an alkylene oxide polymerization catalyst corresponding to the formula:M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y • pM³wA²zwherein:M¹ and M⁴ each represent a metal ion independently selected from Zn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Mo⁴⁺, Mo⁶⁺, Al³⁺, V⁴⁺, V⁵⁺, Sr²⁺, W⁴⁺, W⁶⁺, Mn²⁺, Sn²⁺, Sn⁴⁺, Pb²⁺, Cu²⁺, La³⁺, and Cr³⁺;M² and M⁵ each represent a metal ion independently selected from Fe³⁺, Fe²⁺, Co³⁺, Co²⁺, Cr²⁺, Cr³⁺, Mn²⁺, Mn³⁺, Ir³⁺, Ni²⁺, Rh³⁺, Ru²⁺, V⁴⁺, V⁵⁺, Ni²⁺, Pd²⁺, and Pt²⁺;M³ represents at least one magnesium, Group 3 - Group 15 metal, or lanthanide series metal or semi-metal ion;X¹ represents a group other than cyanide that is coordinated with the M² ion;X² represents a group other than cyanide that is coordinated with the M⁵ ion;A¹ represents a halide, nitrate, sulfate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, perchlorate, isothiocyanate, an alkanesulfonate, an arylenesulfonate, trifluoromethanesulfonate, or a C₁₋₄ carboxylate;A² represents least one alkoxide, aryloxy, carboxylate, acyl, pyrophosphate, phosphate, thiophosphate, dithiophosphate, phosphate ester, thiophosphate ester, amide, oxide, siloxide, hydride, carbamate, or hydrocarbon anion;b, c and d are each numbers that reflect an electrostatically neutral complex, provided that b and c each are greater than zero;x and y are integers that balance the charges in the metal salt M³xA¹y;r is an integer from 4 to 6;t is an integer from 0 to 2;n is a number from 0 and 20;p is from 0.002 to 10; andw and z are integers that balance the charges in the metal salt M³zA²z, provided that w is from 1 to 4;II) forming a reaction mixture comprising:A) a polyol mixture comprising(A-1) 80 to 99 weight percent, based on the total weight of the polyol mixture (A), of one or more polyether polyols having a nominal functionality of 2 to 4, a hydroxyl number of 18 to 50 mg KOH / g, and an oxyethylene content of at most 35% by weight, wherein at least 30% of the weight of the one or more polyether polyols (A-1) is an ethylene oxide-capped poly(propylene oxide) and wherein at least a portion of the one or more polyether polyols (A-1 contains dispersed solid polymer particles;(A-2) 1 to 10 weight percent, based on the total weight of the polyether polyol mixture (A), of the polyether polyol produced in step I; and(A-3) 0 to 10 weight percent, based on the total weight of the polyol mixture (A), of one or more additional polyols, different from polyether polyols (A-1) and (A-2), having number average molecular weights greater than 250 g / mol;B) 1 to 6 parts by weight water per 100 parts by weight of the polyol mixture (A);C) 1 to 5 parts by weight per 100 parts by weight of the polyol mixture (A) of a crosslinker having 3 to 8 isocyanate-reactive groups per molecule and a formula molecular weight of up to 250 g / mol;D) a silicone surfactant;E) a catalytically effective amount of at least one urethane catalyst; andF) a polyisocyanate having an isocyanate functionality of 1.95 to 2.2 and an isocyanate content of 28 to 50% by weight, in an amount sufficient to produce an isocyanate index of 90 to 125, and(II) curing the reaction mixture to produce the polyurethane foam.The presence of polyol (A-2) quite unexpectedly does not cause foam collapse, quite unlike the case in which a similar polyol is made using a conventional zinc hexacyanocobaltate polymerization catalyst complex. To the contrary, stable foams are not only produced but in addition have been found to have excellent properties.The one or more polyether polyols (A-1), including the weight of the dispersed polymer particles, constitutes 80 to 99 weight percent of the total weight of the mixture of polyols (A). In some embodiments, the one or more polyether polyols (A-1) constitute at least 82% or at least 85% of the total weight of the mixture of polyols (A). The one or more polyether polyols (A-1) in some embodiments may constitute up to 98%, up to 97% or up to 96% of the total weight of the mixture of polyols (A).Each of the one or more polyether polyols (A-1) have a nominal functionality of 2 to 4, preferably 2 to 3, especially 3. Each of the one or more polyols (A-1) has a hydroxyl number of 18 to 50 mg KOH / g, preferably 20 to 50 mg KOH / g and more preferably 22 to 50 mg KOH / g, as measured according to ASTM 4274-16. Each of the one or more polyether polyols A-1) has an oxyethylene content (i.e., content of polymerized ethylene oxide) of at most 35% by weight. The oxyethylene content may be, for example, 10 to 35% or 15 to 30%.At least 30% of the weight of the one or more polyether polyols (A-1) is an ethylene oxide-capped poly(propylene oxide). The ethylene oxide-capped poly(propylene oxide) can be prepared by homopolymerizing propylene oxide or (less preferably) randomly polymerizing a mixture of 85 to 99 weight percent propylene oxide and 1 to 15 weight percent ethylene oxide in the presence of any suitable polymerization catalyst to form an intermediate, followed by polymerizing ethylene oxide onto the end of the intermediate. The ethylene oxide-capped poly(propylene oxide may constitute at least 40%, at least 50%, at least 60% or at least 70% of the total weight of the one or more polyether polyols (A-1), and as much as 100% or as much as 98% thereof. The ethylene oxide cap may constitute, for example, 10 to 30% of the total weight of the ethylene oxide-capped poly(propylene oxide). Preferably, 50 to 100% of the hydroxyl groups of ethylene oxide-capped poly(propylene oxide) are primary hydroxyl groups, the remainder if any being secondary hydroxyl groups.Some or all of the polymer particles may be grafted onto some or all of polyether polyol with (A-1). The polymer particles may be formed in situ in all or part of polyether polyol (A-1) by polymerizing monomers and or polymer precursors in the presence of the polyether polyol. Alternatively, the polymer particles can be made and dispersed into all or part of polyether polyol (A-1) using mechanical dispersion techniques. The polymer particles may be, for example, polystyrene, styrene-acrylonitrile, polyacarylonitrile, polyolefin, polyurethane, polyurea, polyamide, polyurethane-urea, or polyhydrazide particles. Suitable polymer polyols include the so-called “PIPA” (polyisocyanate polyaddition) polyols and “PHD” polyols. The solid polymer particles may constitute, for example 0.25 to 10 percent of the total weight of the polyol mixture (A).Component (A-1) may be provided as a mixture of (1) a polymer polyol and (2) an ethylene oxide-capped poly(propylene oxide) having a nominal functionality of 2 to 4, a hydroxyl number of 10 to 50 mg KOH / g and an oxyethylene content of at most 35% by weight, which does not contain dispersed polymer particles. For example, component (A-1) be provided as a mixture of, for example, 10 to 70 weight percent of the polymer polyol (1) and 30 to 90 weight percent of the ethylene oxide-capped poly(propylene oxide) (2). The polyol phase of the polymer polyol is a polyether polyol, preferably a polymer or copolymer of propylpene oxide and even more preferably an ethylene oxide-capped poly(propylene oxide) having a nominal functionality of 2 to 4, a hydroxyl number of 10 to 50 mg KOH / g and an oxyethylene content of at most 35% by weight. The dispersed solid polymer particles of polymer polyol (1) are preferably styrene, acrylonitrile or styrene-acrylonitrile particles. The polymer polyol (1) may contain, for example, 20 to 60 weight-percent of the dispersed solid polymer particles.Polyether polyol (A-2) constitutes 1 to 10 weight percent, preferably 2.5 to 7.5 weight percent, of the total weight of the polyol mixture (A).Polyether polyol (A-2) has a nominal hydroxyl functionality of 2 to 4, preferably 2 to 3 and most preferably 3. 50 to 75%, preferably 60 to 70%, by number (or, equivalently, by weight) of the hydroxyl groups of polyether polyol (A-2) are primary hydroxyl groups, the remainder being secondary hydroxyl groups. Polyether polyol (A-2) has a hydroxyl number of 25 to 50 mg KOH / g, preferably 35 to 50 or 40 to 50 mg KOH / g, as measured according to ASTM 4274-16. Polyether polyol (A-2) is produced by copolymerizing an oxide mixture comprising 60 to 80 wt.-%, based on the weight of the oxide mixture, of ethylene oxide and correspondingly 40 to 20 wt.-%, based on the weight of the oxide mixture, of propylene oxide onto a starter or mixture of starters having 2 to 4, preferably 2 to 3 and most preferably 3 hydroxyl groups.The starter compound will have a hydroxyl equivalent weight less than that of the product (A-2). It may have a hydroxyl equivalent weight of from 30 to 500 g / equivalent or more. The equivalent weight may be up to 500, up to 250, up to 125, and / or up to 100 g / equivalent. Examples of starters include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butane diol, 1,6-hexane diol, 1,8-octane diol, cyclohexane dimethanol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, and alkoxylates (such as ethoxylates and / or propoxylates) of any of these that have a hydroxyl equivalent weight less than that of the product of the polymerization. The starter compound also can be water. The starter may be neutralized with or contain a small amount of an acid, as described in U.S. Patent No. 6,077,978 and U.S. Patent Publication Application No. 2005-0209438.The copolymerization of the oxide mixture is performed in the presence of an alkylene oxide polymerization catalyst corresponding to the formula:M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y • pM³wA²z, wherein M¹, M², M³, M⁴, M⁵, A¹, A², X¹, X², b, c, d, n, p, r, t, w, x, y and z are as defined before.M¹ and M⁴ each most preferably are zinc. M² and M⁵ each most preferably are iron and cobalt, especially cobalt. M³ is preferably one or more of aluminum, gallium, hafnium, indium and manganese. M³ may be a mixture of aluminum and gallium, aluminum and hafnium, aluminum and indium or aluminum and manganese; in any of these mixtures, the mole ratio of aluminum to the other M³ metal may be, for example, 0:05:1 to 20:1, 0.25 to 10, or 0.5 to 5. M³ may be aluminum by itself.r is most preferably 6 and t is most preferably zero. d is most preferably 0 to 1.The mole ratio of the M¹ metal and the M⁴ metal combined to the M² and the M⁵ metal combined is preferably 0.8:1 to 20:1 or 1.0 to 5.0. The relative amounts of the metals M¹-M⁵, as well as their various ratios, are conveniently determined using nuclear activation analysis methods.Catalyst complexes of the foregoing formula can be made in a coprecipitation process as described in WO 2018 / 209069, incorporated herein by reference. In such a process, solutions of a water soluble M¹ metal salt and a water soluble cyanometallate compound having an M³ metal cyanometallate group are combined in the presence of an M³ metal compound. The M³ metal compounds may be insoluble in the solvent or, if soluble, may react during the preparation of the catalyst complex to form an insoluble reaction product that becomes part of the catalyst complex, in which case the M³wA²z entity is different than the M³ metal compound. For example, the M³ compound may react with water during the catalyst preparation to form the corresponding metal oxide. A catalyst complex of the foregoing formula precipitates. The catalyst complex may be washed one or more times with water and / or a complexing agent, also as described in WO 2018 / 209069.The formula M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y • pM³wA²z is not intended to denote any special crystalline form or other spatial or chemical relationship between the M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d, M⁴xA¹y and M³wA²z components of the catalyst complex. In some embodiments the catalyst complex comprises hybrid particles having an M¹b[M²(CN)r(X¹)t]c phase and one or more M³wA²z phases. The M⁴xA¹y phase, when present, is believed to reside at least partially on particles of the M¹b[M²(CN)r(X¹)t]c phase. In addition to such hybrid particles, the catalyst complex may contain particles of the M¹b[M²(CN)r(X¹)t]c phase and / or of a M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y phase only, and other particles of the M⁴xA¹y phase only. Some or all of the M³wA²z component may be present as separate particles.The anion A² may be, for example, one or more of alkoxide, aryloxy, carboxylate, acyl, pyrophosphate, phosphate, thiophosphate, dithiophosphate, phosphate ester, thiophosphate ester, amide, oxide, siloxide, hydride, carbamate and / or hydrocarbon anion. Exemplary embodiments include the oxide, hydrocarbyl, oxide and / or the alkoxide ions. In preferred embodiments, the anion is not a halide anion or a cyanide anion.M³ may be gallium. Examples of useful starting gallium compounds include trialkyl gallium compounds such as trimethylgallium, triethyl gallium, tributyl gallium, tribenzylgallium and the like; gallium oxide; gallium alkoxides such as gallium trimethoxide, gallium triethoxide, gallium triisopropoxide, gallium tri-t-butoxide, gallium tri-sec-butoxide and the like; gallium aryloxides such as gallium phenoxide and gallium phenoxides in which one or more of the phenoxide groups is ring-substituted with one or more of alkyl, CF₃, cyano, COCH₃, halogen, hydroxyl, alkoxyl and the like; gallium carboxylates such as gallium formate, gallium acetate, gallium propionate, gallium 2-ethylhexanoate, gallium benzoate, gallium benzoates in which one or more of the benzoate groups is ring-substituted with one or more of alkyl, CF₃, cyano, COCH₃, halogen, hydroxyl, alkoxyl and the like, gallium salicylate, gallium 3,5-di-t-butyl salicylate; gallium amides such as gallium tris(dimethylamide), gallium tris(diethylamide), gallium tris(diphenylamide), gallium tris(di(trimethylsilyl)amide) and the like; gallium acetylacetonate; gallium t-butylacetylacetonate; and alkylgallium alkoxides such as diethylgallium ethoxide, dimethylgallium ethoxide, diethylgallium isopropoxide and dimethylgallium isopropoxide.M³ may be hafnium. Examples of useful starting hafnium compounds include hafnium alkyls such as such as tetraethyl hafnium, tetrabutyl hafnium, tetrabenzyl hafnium and the like; hafnium oxide; hafnium alkoxides such as hafnium tetramethoxide, hafnium tetraethoxide, hafnium tetraisopropoxide, hafnium tetra-t-butoxide, hafnium tetra-sec-butoxide and the like; hafnium aryloxides such as hafnium phenoxide and hafnium phenoxides in which one or more of the phenoxide groups is ring-substituted with one or more of alkyl, CF₃, cyano, COCH₃, halogen, hydroxyl, alkoxyl and the like; hafnium carboxylates such as hafnium formate, hafnium acetate, hafnium propionate, hafnium 2-ethylhexanoate, hafnium benzoate, hafnium benzoates in which one or more of the benzoate groups is ring-substituted with one or more of alkyl, CF₃, cyano, COCH₃, halogen, hydroxyl, alkoxyl and the like, hafnium salicylate, hafnium 3,5-di-t-butyl salicylate; hafnium amides such as hafnium tetra(dimethylamide), hafnium tetra(diethylamide), hafnium tetra(diphenylamide), hafnium tetra((bistrimethylsilyl)amide); hafnium acetylacetonate and hafnium t-butylacetylacetonate.M³ may be indium. Examples of useful starting indium compounds include trialkyl indium compounds like trimethyl indium; indium oxide; indium alkoxides such as indium methoxide, indium ethoxide, indium isopropoxide, indium t-butoxide, indium sec-butoxide and the like; indium aryloxides such as indium phenoxide and indium phenoxides in which one or more of the phenoxide groups is ring-substituted with one or more of alkyl, CF₃, cyano, COCH₃, halogen, hydroxyl, alkoxyl and the like; indium carboxylates such as indium formate, indium acetate, indium propionate, indium 2-ethylhexanoate, indium benzoate, indium benzoates in which one or more of the benzoate groups is ring-substituted with one or more of alkyl, CF₃, cyano, COCH₃, halogen, hydroxyl, alkoxyl and the like, indium salicylate, indium 3,5-di-t-butyl salicylate; indium acetylacetonate; and indium t-butylacetylacetonate.M³ may be aluminum. Examples of useful starting aluminum compounds include trialkyl aluminum compounds such as trimethylaluminum, triethyl aluminum, tributyl aluminum, tribenzylaluminum and the like; aluminum alkoxides such as aluminum trimethoxide, aluminum triethoxide, aluminum triisopropoxide, aluminum tri-t-butoxide, aluminum tri-sec-butoxide and the like; aluminum aryloxides such as aluminum phenoxide and aluminum phenoxides in which one or more of the phenoxide groups is ring-substituted with one or more of alkyl, CF₃, cyano, COCH₃, halogen, hydroxyl, alkoxyl and the like; aluminum oxide; aluminum carboxylates such as aluminum formate, aluminum acetate, aluminum propionate, aluminum 2-ethylhexanoate, aluminum benzoate, aluminum benzoates in which one or more of the benzoate groups is ring-substituted with one or more of alkyl, CF₃, cyano, COCH₃, halogen, hydroxyl, alkoxyl and the like, aluminum salicylate, aluminum 3,5-di-t-butyl salicylate; aluminum amides such as aluminum tris(dimethylamide), aluminum tris(diethylamide), aluminum tris(diphenylamide), aluminum tris(di(trimethylsilyl)amide) and the like; aluminum acetylacetonate; aluminum t-butylacetylacetonate; and alkylaluminum oxides and alkoxides such as diethylaluminum ethoxide, dimethylaluminum ethoxide, diethylaluminum isopropoxide, dimethylaluminum isopropoxide, methyl aluminoxane, tetraethyldialuminoxane and the like.M³ may be manganese. Examples of useful starting manganese compounds include Mn(II) and / or Mn(III) and / or Mn(IV) compounds include manganese phosphate; pyrophosphate, manganese oxide; manganese alkoxides such as manganese methoxide, manganese ethoxide, manganese isopropoxide, manganese t-butoxide, manganese sec-butoxide and the like; manganese aryloxides such as manganese phenoxide and manganese phenoxides in which one or more of the phenoxide groups is ring-substituted with one or more of alkyl, CF₃, cyano, COCH₃, halogen, hydroxyl, alkoxyl and the like; manganese carboxylates such as manganese formate, manganese acetate, manganese propionate, manganese 2-ethylhexanoate, manganese benzoate, manganese benzoates in which one or more of the benzoate groups is ring-substituted with one or more of alkyl, CF₃, cyano, COCH₃, halogen, hydroxyl, alkoxyl and the like, manganese salicylate, manganese 3,5-di-t-butyl salicylate; manganese acetylacetonate; and manganese t-butylacetylacetonate.Examples of other starting M³ metal compounds are described, for example, in WO 2018 / 209069.The amount of catalyst complex may be from 1 to 5000 ppm based on the weight of the product. The amount of catalyst complex may be at least 2 ppm, at least 5 ppm, at least 10 ppm, at least 25 ppm, or up to 500 ppm or up to 200 ppm or up to 100 ppm, based on the weight of the product. The amount of catalyst complex may be selected to provide 0.25 to 20, 0.5 to 10, 0.5 to 1 or 0.5 to 2.5 parts by weight of the M¹ metal (preferably cobalt) per million parts by weight of the product. The catalyst and / or residues thereof are conveniently left in polyether polyol (A-2). Thus, polyether polyol (A-2) may contain, for example, 0.25 to 20, 0.5 to 10, 0.5 to 1 or 0.5 to 2.5 parts by weight of the M² metal (preferably cobalt) per million parts by weight of the product, in the form of catalyst or catalyst residues.The polymerization to produce polyol (A-2) typically is performed at an elevated temperature. The polymerization temperature may be, for example, 70°C to 220°C (e.g., from 120°C to 190°C). The polymerization reaction usually may be performed at superatmospheric pressures but can be performed at atmospheric pressure or even sub-atmospheric pressures. A preferred pressure is 0 to 10 atmospheres, especially 0 to 6 atmospheres, gauge pressure. The polymerization preferably is performed under vacuum or under an inert atmosphere such as a nitrogen, helium or argon atmosphere. Carbon dioxide is either absent or present in at most an amount as indicated above with regard to carbonate precursors.Polyether polyol (A-2) may be produced in a semi-batch process with continuous addition of starter. In such a semi-batch process, alkylene oxide and additional starter (and optionally additional catalyst complex) are continuously added to the reaction vessel as the polymerization proceeds, but product is not removed until the polymerization is completed.Polyether polyol (A-2) is most preferably produced in a continuous process. In a continuous process, starter, alkylene oxide and catalyst are continuously added into the reactor vessel, and a product stream is continuously withdrawn. A tubular reactor that has multiple points for injecting the starting materials, a loop reactor, and a continuous stirred tank reactor (CSTR) are all suitable types of vessels for continuous polymerization processes. The reactor should be equipped with a means of providing or removing heat so the temperature of the reaction mixture can be maintained within the required range. A cook-down step performed on continuously withdrawn product is conveniently conducted in a reactor that prevents significant back-mixing from occurring. Plug flow operation in a pipe or tubular reactor is a preferred manner of performing such a cook-down step.Crude product obtained in any of the foregoing processes may contain up to 0.5% by weight, based on the total weight, of unreacted alkylene oxide; small quantities of the starter compound and low molecular weight alkoxylates thereof; and small quantities of other organic impurities and water. Volatile impurities should be flashed or stripped from the resultant crude product. Catalyst residues preferably are left in the product, but these can be removed if desired. Moisture and volatiles can be removed by stripping the polyol.Polyol (A-3), if present at all, constitutes up to 10, preferably up to 5 weight percent of the combined weight of all polyether polyols. It may be absent. Examples of polyols (A-3) include, for example, polyester polyols; and polyether polyols different from polyols (A-1) and (A-2), such as polyether polyols having molecular weights greater than 250 g / mol (by gel permeation chromatography against polystyrene standards) and hydroxyl numbers greater than 50 mg KOH / g that may have nominal functionalities of 4 to 8.The mixture of polyols (A) preferably contains no more than 0.1 weight-percent of any polyether polyol having a nominal functionality of 2 to 4 and a hydroxyl number of 25 to 50 mg KOH / g, wherein 50 to 75% of the hydroxyl groups of polyether polyol (A-1) are primary hydroxyls which is produced by copolymerizing an oxide mixture comprising 60 to 80 wt.-%, based on the weight of the oxide mixture, of ethylene oxide and correspondingly 40 to 20 wt.-%, based on the weight of the oxide mixture, of propylene oxide in the presence of an alkylene oxide polymerization catalyst corresponding to the formula: M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y • pM³wA²z wherein the variables are as described before except p is 0. The mixture of polyols (A) most preferably is devoid of such a polyether polyol. The mixture of polyols (A) may contain no more than 0.1 weight percent of any polyether polyol produced by polymerizing an alkylene oxide in the presence of an alkylene oxide polymerization catalyst corresponding to the formula: M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y • pM³wA²z wherein the variables are as described before except p is 0, and may be devoid of any such polyether polyol.The crosslinker (component C) of the reaction mixture) is present in an amount of 1 to 5 parts by weight, preferably up to 1.5 to 3 or 1.5 to 3 parts by weight, per 100 parts by weight of the polyol mixture (A). Suitable crosslinkers have 3 to 8 isocyanate-reactive groups per molecule. The isocyanate-reactive groups may be hydroxyl, primary amino or secondary amino groups, for example. Suitable crosslinkers have formula molecular weights of up to 250 g / mol, preferably up to 150 g / mol or up to 125 g / mol. Examples include but are not limited to glycerin, trimethylolpropane, triethanolamine, diethanolamine and monoethanolamine.Suitable surfactants include, but are not limited to, silicones such as silicone oils and organosilicone-polyether copolymers, including polydimethyl siloxane and polydimethylsiloxane-polyoxyalkylene block copolymers such as are described in U.S. Patent 4,483,894. Other suitable surfactants are linear siloxane-polyoxyalkylene bock copolymers having an average molecular weight of at least 30,000 such as are disclosed in U.S. Patent 4,022,722. Suitable surfactants are widely commercially available from Evonik Industries, Momentive Performance Materials and Dow, Inc. The silicone surfactant component may constitute, for example, at least 0.25% and up to 5% of the total weight of the polyol mixture (A). A preferred amount is at least 0.5% or at least 1%, and up to 4% or up to 3%, on the same basis.Urethane catalysts for purposes of this invention catalyze the reaction between an isocyanate group and an alcohol group and / or water. Among suitable urethane catalysts are tin (II) and tin (IV) catalysts, catalysts that contain other Group III to Group XV metals, tertiary amine compounds, amidines, tertiary phosphines, and the like. Among the useful urethane catalysts are, for example, trimethylamine, triethylamine, N-methylmorpholine, N-ethylmorpholine, N,N-dimethylbenzylamine, N,N-dimethylethanolamine, dialkylimidazole compounds, 2,2'-dimorpholinodiethylether, N,N,N',N'-tetramethyl-1,4-butanediamine, N,N-dimethylpiperazine, 1,4-diazobicyclo-2,2,2-octane, tetraalkyl guanidine compounds, 2,2,2-dimethylaminoethoxyethyl methylaminoethanol, N,N-dimethylcyclohexylamine, 1,3,5-tris[3-(dimethylamino)propyl]hexahydro-1,3,5-triazine, triethylenediamine, dimethylalkylamines where the alkyl group contains from 4 to 18 carbon atoms, pentamethyldiethylene triamine, tetramethyl ethylene diamine, dibutyl tin dilaurate, dimethyltin dilaurate, stannous octoate, stannous oleate, stannic chloride, stannous chloride, di-n-butyl tin bis(mercaptoacetic acid isooctyl ester) and other organotin compounds of the formula SnRn(OR)₄₋ₙ, wherein R is alkyl or aryl and n is 0-2. Mixture of two or more urethane catalysts may be used.The urethane catalyst is present in a catalytically effective amount. Tertiary amine and amidine catalysts, for example, may be present when used in an amount of 0.1 to 5 parts or 0.25 to 2 parts by weight per 100 parts by weight of the mixture of polyether polyols. Tin catalysts may be present when used in an amount of 0.01 to 1 or 0.1 to 0.25 parts by weight per 100 parts by weight of the mixture of polyether polyols.The polyisocyanate may have an isocyanate equivalent weight of up to 300 g / equivalent, for example. The isocyanate equivalent weight may be up to 250, up to 175, and in some embodiments is 80 to 175 g / equivalent. If a mixture of polyisocyanate compounds is used, these equivalent weights apply with respect to the mixture; individual polyisocyanate compounds in such a mixture may have isocyanate equivalent weights above, within or below those ranges.Examples of useful polyisocyanates include m-phenylene diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, hexamethylene-1,6-diisocyanate, tetramethylene-1,4-diisocyanate, cyclohexane-1,4-diisocyanate, hexahydrotoluene diisocyanate, naphthylene-1,5-diisocyanate, 1,3- and / or 1,4-bis(isocyanatomethyl)cyclohexane (including cis- and / or trans isomers), methoxyphenyl-2,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, hydrogenated diphenylmethane-4,4'-diisocyanate, hydrogenated diphenylmethane-2,4'-diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, 3,3'-dimethyldiphenyl methane-4,4'-diisocyanate, 4,4',4"-triphenyl methane triisocyanate, polymethylene polyphenylisocyanate (PMDI), toluene-2,4,6-triisocyanate and 4,4'-dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate. Preferably the polyisocyanate is diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,2'-diisocyanate, PMDI, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate or mixtures thereof. Diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate and mixtures thereof are generically referred to as MDI, and all can be used. “Polymeric MDI”, which is a mixture of PMDI and MDI, can be used. Toluene-2,4-diisocyanate, toluene-2,6-diisocyanate and mixtures thereof are generically referred to as TDI, and all can be used.The polyisocyanate is present (prior to any reaction) in an amount sufficient to produce an isocyanate index of 90 to 125. A preferred isocyanate index is at least 95, at least 98, at least 100 or at least 102 and up to 120, up to 115 or up to 110. Isocyanate index is 100 times the ratio of the number of isocyanate groups to the number of isocyanate-reactive groups in the reaction mixture, prior to any reaction.The reaction mixture may further contain optional ingredients such as a flame retardant, one or more fillers and / or reinforcing agents such as fiber glass, carbon fibers, flaked glass, mica, talc, melamine and calcium carbonate; one or more pigments and / or colorants such as titanium dioxide, iron oxide, chromium oxide, azo / diazo dyes, phthalocyanines, dioxazines and carbon black; one or more biocides; one or more preservatives; one or more antioxidants; one or more flame retardants; and the like. Although the foam formulation may further contain one or more polyols and polyamines in addition to the polyether polyols and optional crosslinkers described above, such ingredients, if present at all, preferably are present in small quantities such as up to 10 parts by weight, up to 5 parts by weight or up to 2 parts by weight per 100 parts by weight of the mixture of polyether polyols, and may be absent altogether.Additional blowing agents may be present in the reaction mixture. These include, for example, additional chemical blowing agents such as azo blowing agents, as well as physical blowing agents of various types.Polyurethane foam is made by combining the various ingredients to form a reaction mixture which is then cured. The order of mixing is generally not critical although it is preferred to combine the polyisocyanate with the other ingredients last, or at least simultaneously with the mixing of the other ingredients. No special foaming conditions are necessary; therefore, foaming conditions and equipment described in the art for making flexible polyurethane foam are entirely suitable. In general, the isocyanate compounds will react spontaneously with water and the polyols even at room temperature (23°C) and therefore in some embodiments curing is accomplished without heating to an elevated temperature (apart from a temperature rise associated with a reaction exotherm that takes place during the curing). If necessary, heat can be applied to the reaction mixture to speed the curing reaction. This can be done by heating some or all of the ingredients prior to combining them, by applying heat to the reaction mixture as it cures, or some combination of each. If heat is applied, a suitable elevated temperature is 40 to 80°C. Curing is continued until the reaction mixture has expanded and cured sufficiently to form a stable foam.In some embodiments, the curing step is performed in a closed mold. In such a process, the reaction mixture is either formed in the mold itself or formed outside the mold and then injected into the mold, where it cures. The expansion of the reaction mixture as it cures is therefore constrained by the internal surfaces of the mold, as are the size and geometry of the molded part. Enough of the reaction mixture is introduced into the mold such that the resulting foam achieves the wanted density as it expands and fills the mold.In other embodiments, the curing step is performed in a free-rise (or slabstock) process. In the free-rise process, the reaction mixture is poured into an open container such that expansion in at least one direction (usually the vertical direction) occurs against the atmosphere or a lightweight surface (such as a film) that provides negligible resistance to the expansion of the foam. In the free-rise process, the reaction mixture expands in at least one direction essentially unconstrained except by its own weight. The free-rise process may be performed by forming the reaction mixture and dispensing it into a trough or onto a conveyor where it expands and cures.The high resiliency foam so produced may have a foam density of, for example, at least 24 g / L, or at least 28 g / L, as measured according to ASTM D3574, Test A. The foam density may be up to 60 g / L, up to 48 g / L, up to 40 g / L or up to 36 g / L. The high resiliency foam may exhibit a resiliency of at least 30%, at least 40% or at least 50% and as much as 75% or as much as to 60%, as measured by the ball rebound test of ASTM D3574-01. The high resiliency foam may exhibit a 50% compression set of up to 15%, preferably up to 10% or up to 7.5%, as measured according to ASTM D3574-01.The high resiliency foam may exhibit an airflow (after mechanically crushing to open cells) of, for example, 0.5 to 8 L / s, 1 to 5 L / s or 1 to 3 L / s, as measured according to ASTM D3574-01.The high resiliency foam may exhibit an elongation to break of 50 to 300%, 75 to 300% or 100 to 250%.In particular embodiments, the high resiliency foam exhibits a density of 28 to 40 kg / m³, a resiliency of 50 to 75%, an elongation to break of 100 to 250% and an airflow of 1 to 5 L / s.The high resiliency foam of the invention is useful for cushioning applications where high resiliency is required. These applications include, for example, domestic, office and vehicular seating, and as the major foam components of mattresses. The high resiliency foam may be covered with a fabric or other sheet material that can serve a decorative, protective and / or tactile function.The following examples are provided to illustrate the invention and are not intended to limit the scope thereof. All parts and percentages are by weight unless otherwise indicated.Example 1Catalyst 1 Preparation: A jacketed glass reactor is heated to 30°C and purged with nitrogen. 2862.5 parts of a 17% solution of t-butanol and 4.6 parts of aluminum oxide (Catalox Ba, from Sasol North America) are added into the reactor and stirred for 10 minutes, followed by another 321 parts of water. A solution of 93.4 parts of potassium hexacyanocobaltate in 800 g of water is added to the reactor and mixed in. 1824 parts of a 50% solution of zinc chloride is added sub-surface at a rate of 25 mL / minute. The mixture is stirred at high speed for 2 hours at 30°C. 22.5 parts of a 4000 molecular weight poly(propylene oxide) diol are added followed by stirring another hour at 30°C. The solids are isolated and redispersed in 3382.2 parts of an aqueous wash solution containing 49.7% t-butanol and 0.7% of the poly(propylene oxide) diol, isolated and again washed with 2182.2 parts of an aqueous wash solution containing 65.3% t-butanol and 1% of the poly(propylene oxide) diol, isolated once again and washed a third time with 1794.4 parts of an aqueous wash solution containing 97.2% t-butanol and 0.6% of the poly(propylene oxide) diol. The wet filter cake is dried in a vacuum oven at 50°C to constant weight, crushed to produce a powder and seived through a 150 micron mesh using a rotovap. The resulting catalyst complex contains 24.4% zinc, 10.5% cobalt, 0.22% potassium, 2.6% chlorine and 1.6% aluminum by nuclear activation analysis. The value of p in formula (I) is about 3. Its surface area is 19.7 m³ / g by nitrogen physisorption using a Micrometrics ASA instrument.Polyol A-2 is made in a continuous loop reactor at 160°C. Catalyst 1 is slurried into propylene glycol at a 2:98 weight ratio. This slurry is fed into the reactor at a rate of 50 parts per hour. Glycerol containing 75 ppm phosphoric acid is fed into the reactor at a rate 771 parts per hour. Propylene oxide and ethylene oxide are fed into the reactor at rates of 8150 and 24,400 parts per hour. These rates establish a catalyst concentration of 30 ppm, based on expected product. Residence time is 2.7 hours. Upon reaching steady-state conditions, the unreacted oxide content is measured as 1 wt-% by FT-NIR. Product is continuously removed and sparged with nitrogen. The product contains about 73 wt.-% polymerized ethylene oxide, has a nominal functionality of 3, and has a hydroxyl number of 45.5 (1233 hydroxyl equivalent weight).Polyol B is made in a similar manner, replacing Catalyst 1 with a commercially available zinc hexacyanocobaltate catalyst complex sold as Arcol-3® catalyst by Covestro AG. Feed rates are 50 parts per hour for the catalyst slurry, 0.385 parts per hour for the glycerol, 4090 parts of propylene oxide per hour and 12170 parts of ethylene oxide per hour. Catalyst concentration is 60 ppm. Residence time is 3.6 hours. The product contains about 73 wt.-% polymerized ethylene oxide, has a nominal functionality of 3, and has a hydroxyl number of 45.5 (1233 hydroxyl equivalent weight).Foams are made using ingredients as indicated in Table 1. All ingredients except stannous octoate and TDI are mixed for 15 seconds on a laboratory pin mixer at room temperature. The stannous octoate is added, mixed in for another 15 seconds, followed by the TDI and another 3 seconds of mixing. The resulting reaction mixture is poured into a 38 x 38 x 24 cm box lined with a plastic film and allowed to cure at ambient conditions until a stable polyurethane foam is obtained. The foam is demolded and allowed to cure further overnight at room temperature. Resiliency of the resulting foam is measured according to the ball rebound test of ASTM D3574-01, Test H. Density, airflow, tear strength, tensile strength and compression set (at 50% compression) are all measured according to the ASTM D3574-01 test method. Results are as indicated in Table 1.The Base Polyol is a nominally trifunctional, 14 wt.% ethylene oxide-capped poly(propylene oxide) having a hydroxyl number of 27.5 (2040 hydroxyl equivalent weight).The Polymer Polyol is a 40% solids styrene-acrylonitrile dispersion in a nominally trifunctional polyether polyol that contains less than 35% oxyethylene units and has a hydroxyl number of about 50 mg KOH / g. Its hydroxyl number is 30.2 (1858 hydroxyl equivalent weight). The Base Polyol and the Polymer Polyol together constitute polyether polyol (A-1).TDI is an 80 / 20 mixture of the 2,4- and 2,6-isomers of toluene diisocyanate.DEOA is diethanolamine.Catalyst A is 33% solution of triethylene diamine in diethylene glycol.Catalyst B is a 70% solution of bi(2-dimethylaminoethyl)ether in dipropylene glycol.Table 1Ingredient | Parts by Weight--- | --- | --- | ---| Comp. A* | Ex. 1 | Ex. 2Base Polyol | 85 | 85 | 85Polymer Polyol¹ | 10 | 10 | 10Polyol A-2 | 0 | 4.95 | 5Polyol B | 5 | 0.05 | 0DEOA | 2 | 2 | 2Water | 2.51 | 2.51 | 2.51Silicone Surfactant | 0.35 | 0.35 | 0.35Catalyst A | 0.2 | 0.2 | 0.2Catalyst B | 0.025 | 0.025 | 0.025Stannous Octoate | 0.07 | 0.07 | 0.07TDI | 34.47 | 34.47 | 34.47Property | | | --- | --- | --- | ---Resiliency, % | | 53.8 | 56.2Density, lb / ft³ (kg / m³) | | 2.14 (40) | 2.09 (33.44)IFD 25%, lbf (N) | Foam | 12.2 (54) | 12.0 (53)Airflow, ft³ / min (L / s) | Collapses | 2.9 (1.37) | 2.6 (1.23)Tear Strength, lb / in (N / mm) | | 1.4 (0.245) | 1.3 (0.228)Tensile strength, lb / in² (kPa) | | 9 (62.1) | 9.6 (59.3)Elongation (%) | | 122 | 12050% Compression set, % | | 12.4 | 6.3*Comparative. ¹In each case the copolymer polyol provides about 4% dispersed solid polymer particles based on the combined weights of the base polyol, the copolymer polyol, Polyol 1 and Polyol A.Polyol A-2 functions as a cell opener in this foam formulation. Examples 1 and 2, which are made with Polyol A-2, each produce good quality high resiliency foams having good airflow. Comparative Sample A, which is made from an identical formulation as Example 2 except Polyol B replaces Polyol A-2, does not produce a stable foam. Polyol B and Polyol A-2 are both made in the same manner except for the polymerization catalyst used, and each has the same content of oxyethylene units and hydroxyl number. Nonetheless, the presence of Polyol B in the formulation results in foam collapse in Example 1, whereas the foams made with Polyol A-2 each are stable and have good properties.Even very small quantities of Polyol B in the foam formulation have an adverse effect on compression set, as is seen by comparing Examples 1 and 2. In Example 1, Polyol B constitutes only 3% of the combined weights of Polyol B and Polyol A-2, and only 0.15% of the total weight of all polyols. Even at this very low level, compression set is nearly doubled. Thus, although very small amounts of a zinc hexacyanocobaltate-catalyzed cell opener such as Polyol B can be tolerated, best results are obtained when that polyol is absent entirely as in Example 2.

Claims

1. A method of making a polyurethane foam, comprising I) forming a reaction mixture comprising:A) a polyol mixture comprising(A-1) 80 to 99 weight percent, based on the total weight of the polyol mixture (A), of one or more polyether polyols having a nominal functionality of 2 to 4, a hydroxyl number of 18 to 50 mg KOH / g, and an oxyethylene content of at most 35% by weight, wherein at least 30% of the weight of the one or more polyether polyols (A-1) is an ethylene oxide-capped poly(propylene oxide) and wherein at least a portion of the one or more polyether polyols (A-1 contains dispersed solid polymer particles;(A-2) 1 to 10 weight percent, based on the total weight of the polyol mixture (A), of a polyether polyol having a nominal functionality of 2 to 4 and a hydroxyl number of 25 to 50, wherein 50 to 75% of the hydroxyl groups of polyether polyol (A-2) are primary hydroxyls, polyether polyol (A-2) being produced by copolymerizing an oxide mixture comprising 60 to 80 wt.-%, based on the weight of the oxide mixture, of ethylene oxide and correspondingly 40 to 20 wt.-%, based on the weight of the oxide mixture, of propylene oxide in the presence of an alkylene oxide polymerization catalyst corresponding to the formula:M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y • pM³wA²zwherein:M¹ and M⁴ each represent a metal ion independently selected from Zn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Mo⁴⁺, Mo⁶⁺, Al³⁺, V⁴⁺, V⁵⁺, Sr²⁺, W⁴⁺, W⁶⁺, Mn²⁺, Sn²⁺, Sn⁴⁺, Pb²⁺, Cu²⁺, La³⁺, and Cr³⁺;M² and M⁵ each represent a metal ion independently selected from Fe³⁺, Fe²⁺, Co³⁺, Co²⁺, Cr²⁺, Cr³⁺, Mn²⁺, Mn³⁺, Ir³⁺, Ni²⁺, Rh³⁺, Ru²⁺, V⁴⁺, V⁵⁺, Ni²⁺, Pd²⁺, and Pt²⁺;M³ represents at least one magnesium, Group 3 – Group 15 metal, or lanthanide series metal or semi-metal ion;X¹ represents a group other than cyanide that is coordinated with the M² ion;X² represents a group other than cyanide that is coordinated with the M⁵ ion;A¹ represents a halide, nitrate, sulfate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, perchlorate, isothiocyanate, an alkanesulfonate, an arylenesulfonate, trifluoromethanesulfonate, or a C₁₋₄ carboxylate;A² represents least one alkoxide, aryloxy, carboxylate, acyl, pyrophosphate, phosphate, thiophosphate, dithiophosphate, phosphate ester, thiophosphate ester, amide, oxide, siloxide, hydride, carbamate, or hydrocarbon anion;b, c and d are each numbers that reflect an electrostatically neutral complex, provided that b and c each are greater than zero;x and y are integers that balance the charges in the metal salt M³xA¹y;r is an integer from 4 to 6;t is an integer from 0 to 2;n is a number from 0 and 20;p is a number from 0.002 to 10; andw and z are integers that balance the charges in the metal salt M³zA²z, provided that w is from 1 to 4; and(A-3) 0 to 10 weight percent, based on the total weight of the polyol mixture (A), of one or more additional polyols, different from polyether polyols (A-1) and (A-2), having number average molecular weights greater than 250 g / mol;B) 1 to 6 parts by weight water per 100 parts by weight of the polyol mixture (A);C) 1 to 5 parts by weight, per 100 parts by weight of the polyol mixture (A) of a crosslinker having 3 to 8 isocyanate-reactive groups per molecule and a formula molecular weight of up to 250 g / mol;D) a silicone surfactant;E) a catalytically effective amount of at least one urethane catalyst; andF) a polyisocyanate in an amount sufficient to produce an isocyanate index of 90 to 125, and(II) curing the reaction mixture to produce the polyurethane foam.

2. A method of making a polyurethane foam, comprising I) forming a reaction mixture comprising:A) a polyol mixture comprising(A-1) 80 to 99 weight percent, based on the total weight of the polyol mixture (A), of one or more polyether polyols having a nominal functionality of 2 to 4, a hydroxyl number of 18 to 50 mg KOH / g, and an oxyethylene content of at most 35% by weight, wherein at least 30% of the weight of the one or more polyether polyols (A-1) is an ethylene oxide-capped poly(propylene oxide) and wherein at least a portion of the one or more polyether polyols (A-1 contains dispersed solid polymer particles;(A-2) 1 to 10 weight percent, based on the total weight of the polyol mixture (A), of a polyether polyol which is a random copolymer of 60 to 80 wt.-% ethylene oxide and correspondingly 40 to 20 wt.-% propylene oxide having a nominal functionality of 2 to 4 and a hydroxyl number of 25 to 50, wherein 50 to 75% of the hydroxyl groups of polyether polyol (A-2) are primary hydroxyls, wherein polyether polyol (A-2) contains residues of an alkylene oxide polymerization catalyst corresponding to the formula:M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y • pM³wA²zwherein:M¹ and M⁴ each represent a metal ion independently selected from Zn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Mo⁴⁺, Mo⁶⁺, Al³⁺, V⁴⁺, V⁵⁺, Sr²⁺, W⁴⁺, W⁶⁺, Mn²⁺, Sn²⁺, Sn⁴⁺, Pb²⁺, Cu²⁺, La³⁺, and Cr³⁺;M² and M⁵ each represent a metal ion independently selected from Fe³⁺, Fe²⁺, Co³⁺, Co²⁺, Cr²⁺, Cr³⁺, Mn²⁺, Mn³⁺, Ir³⁺, Ni²⁺, Rh³⁺, Ru²⁺, V⁴⁺, V⁵⁺, Ni²⁺, Pd²⁺, and Pt²⁺;M³ represents at least one magnesium, Group 3 - Group 15 metal, or lanthanide series metal or semi-metal ion;X¹ represents a group other than cyanide that is coordinated with the M² ion;X² represents a group other than cyanide that is coordinated with the M⁵ ion;A¹ represents a halide, nitrate, sulfate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, perchlorate, isothiocyanate, an alkanesulfonate, an arylenesulfonate, trifluoromethanesulfonate, or a C₁₋₄ carboxylate;A² represents least one alkoxide, aryloxy, carboxylate, acyl, pyrophosphate, phosphate, thiophosphate, dithiophosphate, phosphate ester, thiophosphate ester, amide, oxide, siloxide, hydride, carbamate, or hydrocarbon anion;b, c and d are each numbers that reflect an electrostatically neutral complex, provided that b and c each are greater than zero;x and y are integers that balance the charges in the metal salt M³xA¹y;r is an integer from 4 to 6;t is an integer from 0 to 2;n is a number from 0 and 20;p is a number from 0.002 to 10; andw and z are integers that balance the charges in the metal salt M³zA²z, provided that w is from 1 to 4; and(A-3) 0 to 10 weight percent, based on the total weight of the polyol mixture (A), of one or more additional polyols, different from polyether polyols (A-1) and (A-2), having number average molecular weights of greater than 250 g / mol;B) 1 to 6 parts by weight water per 100 parts by weight of the polyol mixture (A);C) 1 to 5 parts by weight, per 100 parts by weight of the polyol mixture (A), of a crosslinker having 3 to 8 isocyanate-reactive groups per molecule and a formula molecular weight of up to 250 g / mol;D) a silicone surfactant;E) a catalytically effective amount of at least one urethane catalyst; andF) a polyisocyanate in an amount sufficient to produce an isocyanate index of 90 to 125, and(II) curing the reaction mixture to produce the polyurethane foam.

3. A method of making a polyurethane foam, comprisingI) producing a polyether polyol having a nominal functionality of 2 to 4 and a hydroxyl number of 25 to 50, wherein 50 to 75% of the hydroxyl groups of polyether polyol are primary hydroxyls, by copolymerizing an oxide mixture comprising 60 to 80 wt.-%, based on the weight of the oxide mixture, of ethylene oxide and correspondingly 40 to 20 wt.-%, based on the weight of the oxide mixture, of propylene oxide in the presence of an alkylene oxide polymerization catalyst corresponding to the formula:M¹b[M²(CN)r(X¹)t]c[M⁵(X²)₆]d • nM⁴xA¹y • pM³wA²zwherein:M¹ and M⁴ each represent a metal ion independently selected from Zn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Mo⁴⁺, Mo⁶⁺, Al³⁺, V⁴⁺, V⁵⁺, Sr²⁺, W⁴⁺, W⁶⁺, Mn²⁺, Sn²⁺, Sn⁴⁺, Pb²⁺, Cu²⁺, La³⁺, and Cr³⁺;M² and M⁵ each represent a metal ion independently selected from Fe³⁺, Fe²⁺, Co³⁺, Co²⁺, Cr²⁺, Cr³⁺, Mn²⁺, Mn³⁺, Ir³⁺, Ni²⁺, Rh³⁺, Ru²⁺, V⁴⁺, V⁵⁺, Ni²⁺, Pd²⁺, and Pt²⁺;M³ represents at least one magnesium, Group 3 - Group 15 metal, or lanthanide series metal or semi-metal ion;X¹ represents a group other than cyanide that coordinates with the M² ion;X² represents a group other than cyanide that coordinates with the M⁵ ion;A¹ represents a halide, nitrate, sulfate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, perchlorate, isothiocyanate, an alkanesulfonate, an arylenesulfonate, trifluoromethanesulfonate, or a C₁₋₄ carboxylate;A² represents least one alkoxide, aryloxy, carboxylate, acyl, pyrophosphate, phosphate, thiophosphate, dithiophosphate, phosphate ester, thiophosphate ester, amide, oxide, siloxide, hydride, carbamate, or hydrocarbon anion;b, c and d are each numbers that reflect an electrostatically neutral complex, provided that b and c each are greater than zero;x and y are integers that balance the charges in the metal salt M³xA¹y;r is an integer from 4 to 6;t is an integer from 0 to 2;n is a number from 0 and 20;p is a number from 0.002 to 10; andw and z are integers that balance the charges in the metal salt M³zA²z, provided that w is from 1 to 4;II) forming a reaction mixture comprising:A) a polyol mixture comprising(A-1) 80 to 99 weight percent, based on the total weight of the polyol mixture (A), of one or more polyether polyols having a nominal functionality of 2 to 4, a hydroxyl number of 18 to 50 mg KOH / g, and an oxyethylene content of at most 35% by weight, wherein at least 30% of the weight of the one or more polyether polyols (A-1) is an ethylene oxide-capped poly(propylene oxide) and wherein at least a portion of the one or more polyether polyols (A-1 contains dispersed solid polymer particles;(A-2) 1 to 10 weight percent, based on the total weight of polyol mixture (A), of the polyether polyol produced in step I; and(A-3) 0 to 10 weight percent, based on the total weight of the polyol mixture (A), of one or more additional polyols, different from polyether polyols (A-1) and (A-2), having number average molecular weights of greater than 250 g / mol;B) 1 to 6 parts by weight water per 100 parts by weight of the polyol mixture (A);C) 1 to 5 parts by weight per 100 parts by weight of the polyol mixture (A) of a crosslinker having 3 to 8 isocyanate-reactive groups per molecule and a formula molecular weight of up to 250 g / mol;D) a silicone surfactant;E) a catalytically effective amount of at least one urethane catalyst; andF) a polyisocyanate having an isocyanate functionality of 1.95 to 2.2 and an isocyanate content of 28 to 50% by weight, in an amount sufficient to produce an isocyanate index of 90 to 125, and(II) curing the reaction mixture to produce the polyurethane foam.

4. The method of any of claims 1-3 wherein M¹ is zinc, M² and M⁵ are cobalt, and M⁴ is iron or zinc.

5. The method of any of claims 1-4 wherein M³ is one or more of aluminum, gallium, hafnium, indium and manganese.

6. The method of any of claims 1-5 wherein the polyether polyol (A-3) has a nominal hydroxyl functionality of 2.5 to 3.5 and 55 to 65% of the hydroxyl groups of polyether polyol (A-3) are primary hydroxyl groups.

7. The method of any of claims 1-6 wherein polyether polyol (A-3) constitutes 2.5 to 7.5 weight percent of the polyol mixture.

8. The method of any of claims 1-7 wherein the dispersed polymer particles are polyurea, polyurethane and / or polyhydrazide particles.

9. The method of any of claims 1-7 wherein the dispersed polymer particles are polystyrene, polyacrylonitrile or styrene-acrylonitrile copolymer particles.

10. The method of any of claims 1-9 wherein the one or more polyether polyols (A-1) and the dispersed solid polymer particles (A-2) are provided as a mixture of (1) a polymer polyol and (2) an ethylene oxide-capped poly(propylene oxide) having a nominal functionality of 2 to 4, a hydroxyl number of 10 to 50 mg KOH / g and an oxyethylene content of at most 35% by weight, which does not contain dispersed polymer particles.

11. The method of any of claims 1-10 wherein the polyisocyanate is toluene diisocyanate.

12. A polyurethane foam made according to the method of any of claims 1-11.

13. The polyurethane foam of claim 12 which exhibits a density of 28 to 40 kg / m³, a resiliency of 50 to 75%, an elongation to break of 100 to 250% and an airflow of 1 to 5 L / s.

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