Foam formulations

Abstract

Embodiments of the present disclosure are directed towards foam formulations including a high hydroxyl number polyether polyol, a low hydroxyl number polyether polyol, ammonium polyphosphate, an alkaline earth metal carbonate, blowing agent, and an isocyanate.

Description

FOAM FORMULATIONS Field of Disclosure

[0001] Embodiments of the present disclosure are directed towards foam formulations. Background

[0002] Foams are dispersions in which a gas is dispersed and / or generated in a liquid material, a solid material, or a gel material. Foams can be formed by a chemical reaction of polyol(s) and an isocyanate(s). Foams can be utilized for a number of various applications, including electric vehicle (EV) or stationary storage battery module and / or pack assemblies, among other applications. Summary

[0003] The present disclosure provides various embodiments, including the following. In some embodiments, the present disclosure relates to a rigid foam formulation including: a high hydroxyl number polyether polyol having an average hydroxyl number from 350 to 1,900 mg KOH / g and an average hydroxyl functionality from 1.5 to 8; a low hydroxyl number polyether polyol having an average hydroxyl number from 7 to 70 mg KOH / g and an average hydroxyl functionality from 1.5 to 8; ammonium polyphosphate; an alkaline earth metal salt; blowing agent; and an isocyanate.

[0004] The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list. Detailed Description

[0005] Foam formulations are disclosed herein. The foam formulations, as disclosed herein, can be cured to make foam products that have one or more desirable properties, i.e., a desirable flame rating. The foam formulations as disclosed herein can be rigid foam formulations, e.g. can be cured to make rigid foam products. For instance, the foam products (at a thickness of ≤10 mm) can provide a UL-94 vertical burn rating of V-0 or V-1 or V-2; UL-94 horizontal burn rating of HBF. UL-94 is a known Standard for Tests for Flammability (UL is equivalent to Underwriters Laboratories). UL-94 in vertical test sample alignment provides ratingsincluding V-0 (best performance), V-1 (performance less than V-0), V-2 (performance less than V-1), and Fail (performance less than V-2). Similarly, in horizontal test sample alignment results in HBF (best performance), HF-1 (performance less than HBF), HF-2 (performance less than HF-1), and Fail (performance less than HF-2).

[0006] Surprisingly, the foam formulations, as disclosed herein, can be cured to make foam products that provide a UL-94 vertical burn rating of V-0 or V-1 or V-2, while providing a number of other desirable properties, e.g., a particular density value, a particular elastic modulus, a particular elongation at break, and / or a particular tensile strength, a particular electrical resistivity in contrast to other foams. Such foam products are useful for a number of applications, such as Electric Vehicle (EV) battery module or pack assemblies, among other applications.

[0007] The foam formulations disclosed herein include a high hydroxyl number polyether polyol and a low hydroxyl number polyether polyol. As used herein, the high hydroxyl number polyether polyol has a higher average hydroxyl number as compared to the low hydroxyl number polyether polyol. As used herein, “polyol” refers to a molecule having an average of greater than 1.0 hydroxyl groups per molecule, e.g., an average hydroxyl functionality of greater than 1.0.

[0008] The high hydroxyl number polyether polyol can have an average hydroxyl number (value) from 350 to 1,900 mg KOH / g. All individual values and subranges from 350 to 1,900 mg KOH / g are included; for example, the high hydroxyl number polyether polyol can have an average hydroxyl number from a lower limit of 350, 450, or 500 mg KOH / g to an upper limit of 1,900, 1,500, 1,100, or 900. Average hydroxyl number can be determined according to ASTM D4274-21.

[0009] The high hydroxyl number polyether polyol can have an average hydroxyl functionality from 1.5 to 8. All individual values and subranges from 2 to 8 are included; for example, the high hydroxyl number polyether polyol can have an average hydroxyl functionality from a lower limit of 1.5, 2, 2.5, or 2.7 to an upper limit of 8, 6, 5, or 4. One or more embodiments provide that the high hydroxyl number polyether polyol has an average hydroxyl functionality of 3.0.

[0010] The average hydroxy equivalent weight of polyols, in units of g / mol OH (e.g. g / mol of OH i.e., hydroxyl end groups) can be calculated by dividing 56110 by the average hydroxyl number from ASTM D4274-21. The high hydroxyl number polyether polyol can have a hydroxyl equivalent weight from 30 to 160 g / mol OH. All individual values and subranges from 30 to 160 g / mol OH are included; for example, the high hydroxyl number polyether polyol can have a hydroxyl equivalent weightfrom a lower limit of 30, 50, or 65 g / mol to an upper limit of 160, 120, or 100 g / mol OH.

[0011] The high hydroxyl number polyether polyol can be a glycerine alkoxylated polyether polyol. As used herein, “glycerine alkoxylated polyether polyol” refers to a compound that is made via a reaction of glycerine as the initiator molecule that is reacted with alkylene oxide. Examples of alkylene oxides can include ethylene oxide, propylene oxide, and / or butylene oxide. One or more alkylene oxides may be utilized to make the high hydroxyl number polyether polyol. One or more embodiments provide that the high hydroxyl number polyether polyol is made via a reaction of glycerine and propylene oxide. One or more embodiments provide that the high hydroxyl number polyether polyol does not include structural units derived from ethylene oxide or butylene oxide, i.e., the high hydroxyl number polyether polyol is a glycerine propoxylated polyether polyol. In lieu of glycerine, a number of other initiator molecules for the high hydroxyl number polyether polyol can be utilized. Other initiator molecules include trimethylolpropane, pentaerythritol, erythritol, and sorbitol, among others. For purpose of this disclosure, the high hydroxyl number polyether polyol, can also be one or more of the initiator molecules discussed herein. The high hydroxyl number polyether polyol can be a blend of two or more high hydroxyl number polyether polyols discussed herein.

[0012] The high hydroxyl number polyether polyol can be prepared using known equipment, reaction conditions, and reaction components. The high hydroxyl number polyether polyol may be obtained commercially. For instance, a number of commercially available high hydroxyl number polyether polyols are available under the tradenames VORANOL, VORATRON, SPECFLEX, VORAFORCE, VORALAST, SPECFIL, VORACOR, and VORALUX from The Dow Chemical Company.

[0013] The high hydroxyl number polyether polyol can be from 10 to 30 weight percent (wt%) of the foam formulation based upon 100 wt% of the foam formulation. All individual values and subranges from 10 to 30 wt% are included; for example, the high hydroxyl number polyether polyol can be from a lower limit of 10, 12, or 15 wt% to an upper limit of 30, 28, or 25 wt% based upon 100 wt% of the foam formulation.

[0014] As mentioned, the foam formulations disclosed herein include a low hydroxyl number polyether polyol. The low hydroxyl number polyether polyol can have an average hydroxyl number (value) from 7 to 70 mg KOH / g determined according to ASTM D4274-21. All individual values and subranges from 7 to 70 mg KOH / g are included; for example, the low hydroxyl number polyether polyol can havean average hydroxyl number from a lower limit of 7, 15, or 20 mg KOH / g to an upper limit of 70, 60, or 50.

[0015] The low hydroxyl number polyether polyol can have an average hydroxyl functionality from 1.5 to 8. All individual values and subranges from 1.5 to 8 are included; for example, the low hydroxyl number polyether polyol can have an average hydroxyl functionality from a lower limit of 1.5, or 1.8 to an upper limit of 8, 6, 5, or 4. One or more embodiments provide that the low hydroxyl number polyether polyol has an average hydroxyl functionality of 2.0.

[0016] The average hydroxy equivalent weight of polyols, in units of g / mol OH (e.g. g / mol of OH end groups) can be calculated by dividing 56110 by the average hydroxyl number from ASTM D4274-21. The low hydroxyl number polyether polyol can have an average hydroxyl equivalent weight from 801 to 8014 g / mol OH. All individual values and subranges from 801 to 8014 g / mol OH are included; for example, the low hydroxyl number polyether polyol can have an average equivalent weight from a lower limit of 801, 1,000, 1,500, or 1,750 g / mol OH to an upper limit of 8014, 7,000, 6,000, or 4,000, or 2,500, or 2,250 g / mol OH.

[0017] The low hydroxyl number polyether polyol can be an alkoxylated polyether polyol. One or more alkylene oxides may be utilized to make the low hydroxyl number polyether polyol. One or more embodiments provide that the low hydroxyl number polyether polyol is made via a reaction of a diol and propylene oxide. One or more embodiments provide that the low hydroxyl number polyether polyol is capped with ethylene oxide. The low hydroxyl number polyether polyol can be a blend of two or more low hydroxyl number polyether polyols discussed herein. One or more embodiments provide that the low hydroxyl number polyether polyol is a difunctional polyether polyol

[0018] Further, the low hydroxyl number polyether polyols may be capped with oligomers or polymers of ethylene oxide (EO-capped) that may modify modulus, elongation properties, and / or toughness when compared to resultant rigid foams of similar density. EO-capped low hydroxyl number polyether polyols may have an ethylene oxide (EO) content at a percent by weight (wt%) of 3 wt% to 80 wt%, 3 wt% to 50 wt%, or 3 wt% to 30 wt%. In some cases, low hydroxyl number polyether polyols may include EO-capped polypropylene oxide having an EO content ranging from 3 wt% to 80 wt% or 3 wt% to 50 wt%.

[0019] The low hydroxyl number polyether polyol can be prepared using known equipment, reaction conditions, and reaction components. The low hydroxyl number polyether polyol may be obtained commercially. For instance, a number ofcommercially available low hydroxyl number polyether polyols are available under the tradenames VORANOL, VORATRON, SPECFLEX, VORAFORCE, VORALAST, SPECFIL, VORACOR, and VORALUX from The Dow Chemical Company.

[0020] The low hydroxyl number polyether polyol can be from 10 to 30 wt% of the foam formulation based upon 100 wt% of the foam formulation. All individual values and subranges from 10 to 30 wt% are included; for example, the low hydroxyl number polyether polyol can be from a lower limit of 10, 12, or 15 wt% to an upper limit of 30, 28, or 25 wt% based upon 100 wt% of the foam formulation.

[0021] The foam formulations disclosed herein include a blowing agent. The blowing agent may react under conditions of the foaming reaction to produce a gas. The blowing agent may be referred to as a chemical blowing agent. Examples of the blowing agent include water, formic acid, hydrocarbons, acids, volatile organics, and the like. The physical blowing agents including gases such as chlorofluoro carbons (CFC), hydrochlorofluorocarbons (HCFC), acetone, nitrogen, air, carbon dioxide, and the like and combinations thereof. One or more embodiments provide that the blowing agent is water. The foam formulations disclosed herein may include one or more of chemical blowing agents and physical blowing agents. Blowing agents may be added to the isocyanate-reactive component (i.e., polyol side) or to the isocyanate component and / or during mixing the polyol and isocyanates in amount sufficient to provide the mixture resulting in density of 0.3 to 0.75 g / cm3of foam.

[0022] The blowing agent can be from 0.01 to 5 wt% of the foam formulation based upon 100 wt% of the foam formulation. All individual values and subranges from 0.01 to 5 wt% are included; for example, the blowing agent can be from a lower limit of 0.01, 0.05, or 0.1 wt% to an upper limit of 4, 2, 1.5, 1.0, 0.8 or 0.5 wt% based upon 100 wt% of the foam formulation.

[0023] The foam formulations may include one or more polyester polyols produced by the reaction of one or more carboxylic diacids and polyols having an OH functionality 2 to 4. Suitable carboxylic acids include aromatic diacids or anhydrides such as phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, methyl esters of phthalic, isophthalic, or terephthalic acid, dimethyl terephthalate, trimellitic anhydride, pyromellitic dianhydride, or mixtures thereof; and C4 to C12 aliphatic diacids. Suitable polyols for the formation of polyesters include one or more alkylene glycols or polyalkylene glycols having a hydroxy functionality of 2 to 4, such as ethylene glycol, 1,2- or 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, glycerine, and the like. Example polyester polyols include polyesters of phthalic anhydride and diethylene glycol, and polyesters of a C4 to C12diacid such as succinic acid or adipic acid and diethylene glycol. Polyester polyols may have an average hydroxyl number, as determined according to ASTM D4274- 21, in a range of 100 mg KOH / g to 500 mg KOH / g, 150 mg KOH / g to 450 mg KOH / g, or 200 mg KOH / g to 450 mg KOH / g. Isocyanate-reactive components may include one or more polyester polyols at a percent by weight (wt%) ranging from 10 wt% to 40 wt%, from 15 wt% to 35 wt%, or from 15 wt% to 30 wt%.

[0024] Isocyanate-reactive components may include one or more silicone polyols having at least two reactive hydroxyl groups. Silicone polyols may include siloxane bonds (Si-O-Si) within the backbone and may further include bivalent alkyl groups separating siloxane units in some cases. Silicone polyols may have the general formula of HO-R1-Si(R2)2-[O-Si(R2)2]n-R1-OH, where each R1 is, independently, a linking group having from 0 to 18 carbon atoms; each R2 is, independently, a group having 2 to 18 carbon atoms such as an alkyl or hydroxyalkyl; and where n is 10 to 20.

[0025] Isocyanate-reactive components may include one or more silicone polyols at a percent by weight (wt%) ranging from 10 wt% to 40 wt%, from 15 wt% to 35 wt%, or from 15 wt% to 30 wt%.

[0026] Isocyanate-reactive components may include one or more aliphatic polyols having at least two reactive hydroxyl groups. Aliphatic polyols include natural and synthetic polyester polyol derivatives include products generated from the reaction of a polyol with one or more hydroxy fatty acids with 10 to 20 carbon atoms, including hydroxycapric acid, hydroxylauric acid, hydroxymyristic acid, hydroxypalmitic acid, hydroxymargaric acid, hydroxystearic acid, hydroxyeicosanoic acid, ricinoleic acid, and the like. For example, aliphatic polyols include triglycerides containing some fraction of hydroxy fatty acids, such as castor oil, or its derivatives, and / or polyols made from epoxidized or hydroformylated natural oil such as soybean oil, cashew nut shell liquid (i.e. CNSL). Aliphatic polyols may have an average hydroxyl equivalent weight in a range of 30 g / mol OH to 2500 g / mol OH, or 30 g / mol OH to 2000 g / mol OH.

[0027] Isocyanate-reactive components may include one or more aliphatic polyols at a percent by weight (wt%) of 2 wt% to 45 wt%, 5 wt% to 35 wt%, 5 wt% to 25 wt%, 5 wt% to 20 wt% or 5 wt% to 10 wt%.

[0028] The foam formulations disclosed herein include ammonium polyphosphate. Ammonium polyphosphate can be referred to as a halogen-free flame retardant or ionic salt additive. Ammonium polyphosphate corresponds to CAS Registry Number 68333-79-9. The ammonium polyphosphate can have phosphorus content from 20wt% to 50 wt% based upon a total weight of the ammonium polyphosphate. The ammonium polyphosphate can have a density of approximately 1.9 g / cm3(ranging from 1.5 to 2.5 g / cm3). The ammonium polyphosphate can have an average particle size (the mass-median diameter, i.e. d50) of 15 to 17 microns (ranging from 5 to 200 microns). The ammonium polyphosphate can be Crystal Phase II (referred to commonly as Phase II APP or APP Phase II) with a degree of polymerization greater than 700 and can have a decomposition temperature greater than 250 °C.

[0029] The ammonium polyphosphate can be from 0.5 to 30 wt% of the foam formulation based upon 100 wt% of the foam formulation. All individual values and subranges from 0.5 to 30 wt% are included; for example, the ammonium polyphosphate can be from a lower limit of 0.5, 1, 3, 5, 7, or 10 wt% to an upper limit of 30, 25, 20, or 18 wt% based upon 100 wt% of the foam formulation.

[0030] The foam formulations disclosed herein include an alkaline earth metal salt, preferably but not limited to alkaline earth metal carbonate. The alkaline earth metal salt can also be a phosphate, chloride, permanganate, and a combination of those with each other or a carbonate. Alkaline earth metal carbonates can be referred to as a halogen-free flame retardant. Examples of alkaline earth metal carbonates include calcium carbonate, magnesium carbonate, barium carbonate, and combinations thereof. One or more embodiments provide that the alkaline earth metal carbonate is calcium carbonate.

[0031] The alkaline earth metal carbonate can have an average particle size (D50) of 1 to 15 microns (can be unimodal or particle size distribution ranging from 0.5 to 100 microns). The alkaline earth metal carbonate can have a density of approximately 2.7 g / cm3(can be ranging from 2 to 3 g / cm3).

[0032] The alkaline earth metal carbonate can have an average particle size (D50) of 1 to 15 microns (can be ranging from 0.5 to 100 microns). The alkaline earth metal carbonate can have a density of approximately 2.7 g / cm3(can be ranging from 2 to 2 g / cm3).

[0033] The alkaline earth metal carbonate can be from 0.5 to 20 wt% of the foam formulation based upon 100 wt% of the foam formulation. All individual values and subranges from 0.5 to 20 wt% are included; for example, the alkaline earth metal carbonate can be from a lower limit of 0.5, 1, 2, or 3 wt% to an upper limit of 20, 15, or 10 wt% based upon 100 wt% of the foam formulation.

[0034] The foam formulations disclosed herein can include a chain extender. Suitable chain extenders are hydroxyl and / or amine functionalized compounds, which also includes compounds generally known as crosslinkers. Chain extenders arecompounds that contain two or more isocyanate-reactive groups, such as hydroxyl groups, primary amines, or secondary amines, but are not limited to, amines, including polyamines; polyhydric alcohols; polyoxyalkylene polyols; polyhydric aromatic compounds, and combinations thereof. Examples of amines include, but are not limited to, diethanolamine, triethanolamine, triisopropanolamine, diisopropanolamine, t-butyltolylenediamine, triaminonane, diethyltolylenediamine, chlorodiaminobenzene, 4,4’-methylene-bis-(3-chloro-2,6-diethylaniline), and combinations thereof. Examples of polyhydric alcohols include, but are not limited to, 1,3 butanediol, 1,4 butanediol, 1,6-hexanediol, ethylene glycols, diethylene glycols, triethylene glycols, 1,2,4-butanetriol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol, 2,5-dimethyl-1,2,6-hexanetriol, glycerol, propylene glycol, dipropylene glycol, tripropylene glycol, and combinations thereof. Examples of chain extenders include ethylene diamine, propylene diamine, diethanolamine, triethanolamine, triisopropanolamine, diisopropanolamine, t-butyltolylenediamine, triaminonane, diethyltolylenediamine, chlorodiaminobenzene, 4,4’-methylene-bis-(3-chloro-2,6- diethylaniline), and combinations thereof. The chain extender can be prepared using known equipment, reaction conditions, and reaction components. The chain extender may be obtained commercially.

[0035] When utilized, the chain extender can be from 0.1 to 5 wt% of the foam formulation based upon 100 wt% of the foam formulation. All individual values and subranges from 0.1 to 5 wt% are included; for example, the chain extender can be from a lower limit of 0.1, 0.5, or 1 wt% to an upper limit of 5, 4, or 3 wt% based upon 100 wt% of the foam formulation.

[0036] The foam formulations disclosed herein can include one or more catalysts. The catalyst may be a blowing catalyst, a gelling catalyst, a trimerization catalyst, or a combination thereof. As used herein, blowing catalysts and gelling catalysts may be differentiated by a general tendency to favor either the urea (blow) reaction, in the case of the blowing catalyst, or the urethane (gel) reaction, in the case of the gelling catalyst; or a tendency to generally enhance both the blow reaction and gel reaction, in case of blowing / gelling catalyst.

[0037] Examples of blowing catalysts, include, but are not limited to, short chain tertiary amines or tertiary amines containing an oxygen. The amine based catalyst may not be sterically hindered. For instance, blowing catalysts include bis-(2- dimethylaminoethyl)ether; pentamethyldiethylene-triamine, triethylamine, tributyl amine, N,N-dimethylaminopropylamine, dimethylethanolamine, N,N,N′,N′-tetra- methylethylenediamine, and combinations thereof, among others. An example of acommercial blowing catalyst is POLYCAT 5, from Evonik, among other commercially available blowing catalysts.

[0038] Examples of gelling catalysts include, but are not limited to, organometallic compounds, cyclic tertiary amines and / or long chain amines, e.g., that contain several nitrogen atoms, and combinations thereof. Organometallic compounds include organotin compounds, such as tin(II) salts of organic carboxylic acids, e.g., tin(II) diacetate, tin(II) dioctanoate, tin(II) diethylhexanoate, and tin(II) dilaurate, and dialkyltin(IV) salts of organic carboxylic acids, e.g., dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate. Bismuth salts of organic carboxylic acids may also be utilized as the gelling catalyst, such as, for example, bismuth octanoate. Cyclic tertiary amines and / or long chain amines include dimethylbenzylamine, triethylenediamine, and combinations thereof., and combinations thereof. Examples of a commercially available gelling catalysts are POLYCAT 8, POLYCAT 9, POLYCAT 203, POLYCAT SA-2LE, DABCO 33 LV, DABCO BL-11, DABCO EG, and DABCO T-12 from Evonik, among other commercially available gelling catalysts.

[0039] Examples of a commercially available trimerization catalysts are POLYCAT 41, DABCO K 2097, and DABCO TMR 30, from Evonik, among other commercially available trimerization catalysts.

[0040] When utilized, the catalyst can be from 0.01 to 5 wt% of the foam formulation based upon 100 wt% of the foam formulation. All individual values and subranges from 0.01 to 5 wt% are included; for example, the catalyst can be from a lower limit of 0.01, 0.1, 0.5, or 1 wt% to an upper limit of 5, 4, or 3 wt% based upon 100 wt% of the foam formulation.

[0041] The foam formulations can include one or more surfactants. Surfactants for use in the preparation of polyurethane foams are well-known to those skilled in the art, and many are commercially available. The surfactant may be a silicone surfactant, a non-silicone surfactant, or a combination thereof. The surfactant may be a hydrocarbon-based organic surfactant. Examples of suitable silicone surfactants include, but are not limited to, TEGOSTAB B-8427, B-8454, B-8404, B-1045, B-8407, B-8409, B-84201, B-84711, B-8715, and B-8462 from Evonik; NIAX L-2171, L-5107, L-5130, L-5180, L-5340, L-5440, L-6100, L-6900, L-6980, and L-6988 from MOMENTIVE, and VORASURF DC 5164, VORASURF SF2937 from The Dow Chemical Company. Examples of non-silicone surfactants include, but are not limited to, oxyethylated alkylphenols, oxyethylated fatty alcohols, paraffin oils, castoroil esters, ricinoleic acid esters, turkey red oil, groundnut oil, paraffins, silicone surfactants, and fatty alcohols.

[0042] When utilized, the surfactant can be from 0.01 to 5 wt% of the foam formulation based upon 100 wt% of the foam formulation. All individual values and subranges from 0.01 to 5 wt% are included; for example, the surfactant can be from a lower limit of 0.01, 0.05, or 0.1 wt% to an upper limit of 5, 4, 3, 2, or 1 wt% based upon 100 wt% of the foam formulation.

[0043] The foam formulations can include one or more additives, e.g., as an additive to the isocyanate-reactive side (polyol side) or on isocyanate side or both. Examples of additives include powder stabilizers, thixotropic agents, such as emulsifiers, diluents, reactive diluents, anti-freeze additive, poloxamer, viscosity modifiers, plasticizers, smoke suppressants, fragrances, reinforcements, dyes, colorants, pigments, preservatives, rheology modifiers, cell stabilizer, inhibitor, odor masks, internal mold release agents, biocides, antioxidants, UV stabilizers, antistatic agents, cell openers, inorganic fillers (including fumed silica, aluminum trihydrates, etc), known fire retardant additives and molecules, and the like. Various amounts of one or more additional known components may be utilized for various applications as desired.

[0044] e foam formulations include an isocyanate. Suitable isocyanates include polyisocyanates, which have an average of greater than 1.0 isocyanate groups per molecule. Examples of suitable isocyanates include, but are not limited to, polymethylene polyphenylisocyanate, toluene 2,4- / 2,6-diisocyanate (TDI), methylenediphenyl diisocyanate (MDI), polymeric MDI, triisocyanatononane (TIN), naphthyl diisocyanate (NDI), 4,4’-diisocyanatodicyclohexylmethane, 3- isocyanatomethyl-3,3,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate IPDI), tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), 2- methylpentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (THDI), dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 4,4’- diisocyanato-3,3’-dimethyldicyclohexylmethane, 4,4’-diisocyanato-2,2- dicyclohexylpropane, 3-isocyanatomethyl-1-methyl-1-isocyanatocyclohexane (MCI), 1,3 -diisooctylcyanato -4 -methylcyclohexane, 1,3 -diisocyanato-2- methylcyclohexane, and combinations thereof. Suitable isocyanates include isocyanate prepolymers, which can be prepared by reacting a stoichiometric excess of one or more isocyanates, with polyol. When preparing an isocyanate prepolymer, it is preferred to have at least a 2:1 stoichiometric ratio of the isocyanate group (NCO) to the hydroxyl group (OH).

[0045] As mentioned, the isocyanate can have an average functionality of greater than 1.0 isocyanate groups per molecule. For instance, the isocyanate can have an average functionality from 1.5 to 5.0. All individual values and subranges from 1.5 to 5.0 are included; for example, the isocyanate can have an average functionality from a lower limit of 1.5, 1.7, 2.0, 2.3, or 2.5 to an upper limit of 5.0, 4.5, 4.0, 3.5, or 3.0.

[0046] The isocyanate can have an isocyanate equivalent weight 80 g / mol NCO to 200 g / mol NCO (e.g. g / mol NCO i.e., of isocyanate end groups) determined according to ASTM D5155. All individual values and subranges from 80 to 200 g / mol NCO are included; for example, the isocyanate can have an isocyanate equivalent weight from a lower limit of 80, 90, 100, 115, or 120 to an upper limit of 200, 175, 160, 150, or 145 g / mol NCO. Isocyanate equivalent weight can be converted to NCO content (%NCO) by this expression: 42.017 g / mol NCO divided by Isocyanate equivalent weight times 100.

[0047] The isocyanate may be prepared by a known process. The isocyanate may be obtained commercially. Examples of commercial isocyanates include, but are not limited to, polyisocyanates under the trade names VORANATE, ISONATE, PAPI, VORACOR, such as VORACOR CL 100 or VORACOR CE 101, and PAPI available from The Dow Chemical Company, among other commercial isocyanates.

[0048] The isocyanate can be from 25 to 75 wt% of the foam formulation based upon 100 wt% of the foam formulation. All individual values and subranges from 25 to 75 wt% are included; for example, the isocyanate can be from a lower limit of 25, 30, or 35 wt% to an upper limit of 75, 65, or 55 wt% based upon 100 wt% of the foam formulation.

[0049] The isocyanate may be utilized to provide an isocyanate index from 105 to 160. All individual values and subranges from 105 to 160 are included; for example, the isocyanate may be utilized to provide an isocyanate index from a lower limit of 105 or 110 to an upper limit of 160, 150, 145, or 130. One or more embodiments provide that the isocyanate may be utilized to provide an isocyanate index of 115. Isocyanate index may be determined as [moles isocyanate groups / moles active hydrogen groups × 100]. Active hydrogen groups in this context, can include hydroxyl groups (-OH) and primary (-NH2) and secondary (>NH) amine groups. For calculation of isocyanate index, 1 mole of water counts as 2 moles of active hydrogen groups.

[0050] Components discussed herein can be mixed together to make a foam formulation. One or more embodiments provide that surfactant(s), catalyst(s), blowing agent(s), and the polyols can be mixed together before they are combinedwith the isocyanate. The foam formulations can be made utilizing known equipment, conditions, and components. The components may be mixed together using equipment such as a spray apparatus, a low pressure impingent mixer, a high pressure impingent mixer, a static mixer, an impingement mixer, an overhead mixing with impellers or paint mixers, a liquid dispensing gun or a mixing head, or static plus dynamic mixer, or a stirred vessel, for instance.

[0051] The foam formulations can be cured to make foam products. In general, the foam formulations are subjected to conditions sufficient to allow the foaming reaction to occur to make the foam products. Known conditions for curing foams can be utilized.

[0052] Advantageously, the foam products made from the foam formulations disclosed herein can provide a UL-94 vertical burn ratings of V-0, V-1, or V-2. As mentioned, UL-94 is a known Standard for Tests for Flammability. UL-94 provides ratings including V-0 (best performance), V-1 (performance less than V-0), V-2 (performance less than V-1), and Fail (performance less than V-2). UL-94 vertical burn rating of V-0, V-1, or V-2 are desirable for a number of applications including electric vehicle (EV) battery assembly where the foam product may or may not be in direct physical contact with lithium ion or sodium ion batteries.

[0053] The foam products made from the foam formulations disclosed herein can have a density from 0.30 g / cm3to 0.9 g / cm3. The foam products may be referred to as high density foams. All individual values and subranges from 0.30 to 0.9 g / cm3are included; for example, the foam product can have a density from a lower limit of 0.30, 0.35, 0.40, or 0.45 g / cm3to an upper limit of 0.9, 0.75, 0.70, 0.65, or 0.60 g / cm3. Density can be determined in accordance with ASTM D1622-08.

[0054] The foam products made from the foam formulations disclosed herein can provide an elastic modulus greater than 100 MPa. For instance, foam products made from the foam formulations disclosed herein provide an elastic modulus from 105 Mpa to 800 Mpa. All individual values and subranges from 105 to 800 Mpa are included; for example, the foam product can provide an elastic modulus from a lower limit of 105, 200, or 350 Mpa to an upper limit of 800, 700, or 650 Mpa. Elastic modulus can be determined in accordance with ASTM D1708-06 or ASTM D638-03.

[0055] The foam products made from the foam formulations disclosed herein can provide an elongation at break greater than 3%. For instance, foam products made from the foam formulations disclosed herein provide an elongation at break from 3.2 % to 10 %. All individual values and subranges from 3.2 to 10 % are included; for example, the foam product can provide an elongation at break from alower limit of 3.2, 3.5, or 3.7 % to an upper limit of 40, 30, 20, 10, 9, or 8 %. Elongation at break can be determined in accordance with ASTM D1708-06 or ASTM D638-03.

[0056] The foam products made from the foam formulations disclosed herein can provide a tensile strength greater than 4 Mpa. For instance, foam products made from the foam formulations disclosed herein provide a tensile strength from 4.01 Mpa to 20 Mpa. All individual values and subranges from 4.01 to 20 Mpa are included; for example, the foam product can provide a tensile strength from a lower limit of 4.01, 4.05, or 4.09 Mpa to an upper limit of 20, 15, or 13 Mpa. Tensile strength can be determined in accordance with ASTM D1708-06 or ASTM D638-03.

[0057] The foam products of the present disclosure can provide a combination of desirable properties. The foam products of the present disclosure are advantageously used for a number of applications, such as automotive applications, among others. Compositions, foam products, multilayer compositions containing one or more foam product layers, and methods of this disclosure are useful for a variety of end applications. Foam products of the present disclosure are useful in various applications, such as Electric Vehicle (EV) battery pack assemblies, among other applications. One or more embodiments provide an EV battery pack assembly comprising a foam product made from a foam formulation disclosed herein. Methods may include preparing the foam formulation by combining the isocyanate component and the isocyanate-reactive component to form a mixture; and reacting the mixture to form the foam product. Composite articles may be prepared by disposing the disclosed composition on a substrate and curing the composition to produce the composite article comprising a foam product on the substrate. In some cases, substrates may define at least one gap, and disposing may include placing the composition in the at least one gap such that the foam product is present within the gap in the composite article. For example, substrates may include battery cell(s), surfaces of metal or plastics or components, and composite articles may include a battery pack and / or module. However, the foam products may be used in other end use applications, including as a pottant or encapsulant in end uses other than battery packs, such as for electric circuits, as well as for purposes other than a pottant and / or encapsulant. Compositions disclosed herein may be used as a pottant or thermal barrier for electrical, battery pack and / or module related applications. If used as pottants, it may cover, encapsulate (completely or partially), and / or protect the electrical connections from the abusive environments such as heat, cold, flame, weather elements, dust,e.g., sand or dirt particles, physical impact or vibration, or other abusive elements. The amount of pottant used may be from a minimum quantity sufficient for coating and protecting the electrical connections up to and including a maximum quantity sufficient to fill voids in a battery cell, junction boxes, and the like. Similarly, can be used as thermal or fire isolation of battery from the external source of thermal or mechanical stress when not in direct contact with the batteries but in contact to the enclosure / casing of the module or pack. High surface energy substrates on which foam formulations disclosed herein can be dispensed include metals such as aluminum, steel or alloys, zinc, and the like of; non-metals, including glass, polar polymers and plastics such as epoxy, polyurethane, or polyester, surface activated non-polar polymers and plastics such as polypropylene, high or low polyethylene; coated materials such as epoxy-coated aluminum, nickel coated steel, polyacrylate- coated aluminum, polyester liner-covered aluminum, polyethylene terephthalate liner- covered steel and the like. Compositions disclosed herein may also be applied in stationary energy storage applications in private and commercial settings. Compositions may be formulated to satisfy constraints for automotive, mobility solutions, e.g., EV, but may be modified outside of those constraints for other related electrical and stationary energy storage applications. For example, a stationary storage application may be formulated at higher densities / weights, where concerns regarding overall weight and the absence of external cooling are not a driving factor. PU compositions disclosed herein may be dispensed on the any listed substrates above using a suitable process such as dispensing, injecting, or spraying into and / or above one or more specific locations of battery pack or module to achieve complete (or partial) fill of a cavity or space. A multilayer composite such that the second self- leveling polyurethane composition either foaming or non-foaming type could be applied on top of or under of a first foam layer resulting from the formulations disclosed herein. The self-leveling of the second layer can be quantified such that the difference in the highest and lowest level of the layer is less than 25% of the highest height of the second layer. One or more embodiments provide a multilayer assembly that provides a UL-94 vertical burn rating of V-0, V-1, or V-2, wherein a layer of the foam product, as discussed herein, is applied in an Electric vehicle (EV) battery assembly and a self-leveling layer of polyurethane product applied on top of the layer of the foam product. EXAMPLES

[0058] In the Examples, various terms and designations for materials are used including, for instance, the following:

[0059] High hydroxyl number polyether polyol (glycerine propoxylated polyol; initiator average hydroxyl functionality 3; average hydroxyl number 640-675 mg KOH / g using ASTM D4274-21; average equivalent weight 85 g / mol OH);

[0060] Low hydroxyl number polyether polyol (propoxylated diol (which is ethylene oxide i.e., EO capped); initiator average hydroxyl functionality 2; average hydroxyl number 27-31mg KOH / g using ASTM D4274-21; average equivalent weight 1955 g / mol OH);

[0061] Chain Extender (1,4-butanediol, obtained from Sigma-Aldrich);

[0062] Blowing agent (water);

[0063] Flame Retardant 1 (ammonium polyphosphate (CAS number 68333- 79-9, phosphorus content 31-32 wt%, crystal Type II, d50 particle size of 15 to 17 microns, decomposition temperature of greater than 275 °C, and density of 1.9 g / cm3); EXOLIT AP 422; obtained from Clariant Corporation);

[0064] Flame Retardant 2 (alkaline earth metal salt; alkaline earth metal carbonate; calcium carbonate; SNOWHITE 12-PT; grade with d50 particle size of 12 microns, and 2.7 g / cm3density obtained from Omya);

[0065] Flame Retardant 3 (alkaline earth metal salt; alkaline earth metal carbonate; coated calcium carbonate; SUPERCOAT grade with d50 particle size of 1.25 microns, 1.2 wt% proprietary hydrophobic coating, and 2.7 g / cm3density; obtained from Imerys);

[0066] Catalyst 1 (gelling catalyst, DABCO BL-11, obtained from Evonik);

[0067] Catalyst 2 (gelling catalyst, DABCO 33 LV, obtained from Evonik);

[0068] Catalyst 3 (delayed action temperature triggered gelling catalyst, POLYCAT SA-2LE, obtained from Evonik);

[0069] Surfactant (silicone polyether surfactant; VORASURF SF 2937; obtained from The Dow Chemical Company);

[0070] Isocyanate (polymethylene polyphenylisocyanate that contains methylene biphenyl diisocyanate (MDI); average functionality 2.7; 32.0 wt% NCO determined according to ASTM D5155).

[0071] Example 1, a foam formulation, was made as follows. Components except the isocyanate were added to a container and mixed with a DAC600.1 Hauschild SpeedMixer at 2,350 rpm for 5 minutes. Then the mixed components were weighed and the desired amount of isocyanate was added and the contents of the container were mixed with a high shear impeller blade at 3,000 rpm for 7 seconds.

[0072] Examples 2-8 and Comparative Examples A-H were made as Example 1 with any changes shown in Tables 1-2.Table 1 Ex Ex Ex Ex Ex Ex Ex Ex 1 2 3 4 5 6 7 8(wt%) Surfactant 028 028 029 029 029 029 030 030Comp Comp Comp Comp Comp Comp Comp Comp Ex Ex Ex Ex Ex Ex Ex ExFlame Retardant - - - - - 3.2 - -, . was poured into a preheated (40 °C) rectangular mold (20 x 20 x 10 cm3) and then the mold was placed into an oven (40 °C) for 30 minutes. Then, Example 9 was demolded, and Property 1 was determined as further discussed herein. For Properties 2-15, determined as further discussed herein, Example 1 (120 g) was utilized, and a rectangular mold (20 x 20 x 5 cm3) was utilized.

[0074] Examples 10-15 and Comparative Examples I-P were made as Example 9 with the change that Examples 2-8 and Comparative Examples A-H were respectively utilized rather than Example 1.

[0075] Values for properties of the foam products are shown in Tables 3-6.Table 3 Ex Ex Ex Ex 9 10 11 12 55Table 4 Ex Ex Ex Ex 13 14 15 16 5Table 5 Comp Ex Comp Ex Comp Ex Comp Ex I J K L 15Table 6 Comp Ex Comp Ex Comp Ex Comp Ex M N O P

[0076] The data of Tables 3-6 show that Examples 9-16 provide a UL-94 vertical burn rating of V-0 or V-1, in contrast to Comparative Examples I-P which provide a UL-94 vertical burn rating of Fail.

[0077] The data of Tables 3-6 show that Examples 9-16 have a density from 0.30 g / cm3to 0.9 g / cm3.

[0078] The data of Tables 3-6 show that Examples 9-16 provide an elastic modulus greater than 100 MPa.

[0079] The data of Tables 3-6 show that Examples 9-16 provide an elongation at break greater than 3%.

[0080] The data of Tables 3-6 show that Examples 9-16 provide a tensile strength greater than 4 MPa.

[0081] Property 1 corresponds to the UL94 Test, which is a Standard for Tests for Flammability of Plastic Materials. To determine Property 1, respective foam samples were cut to 0.5-inch width and ≥ 10 cm dimensions. These samples were then tested in accordance with UL-94 vertical burn protocol. Performance was categorized in appropriate category: V-0 (best performance), V-1 (performance less than V-0), V-2 (performance less than V-1), and Fail (Fail indicating that the pottant sample burns all the way to the clamp during and / or post the flame exposure).

[0082] Property 2 corresponds to electrical resistivity. Electrical resistivity was determined using a Keithley 6517B electrometer with a Keithley 8009 test cell in accordance with ASTM D257. Each sample was measured in this way five times to calculate an average and error bar.

[0083] Properties 3and 4 correspond to dielectric strength and dielectric constant respectively. Dielectric strength was determined using a Hipotronics 750- 2 / D149 dielectric strength tester in accordance with ASTM D149. Dielectric strength is reported as the voltage at failure divided by the sample thickness. Dielectric constant was determined using a Novocontrol Broadband Dielectric Spectrometer in accordance with ASTM D150.

[0084] Property 5 corresponds to thermal conductivity. Thermal conductivity was determined using TPS 2500S Hot Disk equipment with a Kapton-insulated 5465 F1 sensor in accordance with ISO 22007-2 on 5 mm thick pre-cured foamed samples with Isotropic (standard) module at 50 mW heating power and 5 second measurement time and standard analysis. Each sample was measured in this way five times to calculate an average and error bar.

[0085] Property 6 corresponds to glass transition temperature.

[0086] Properties 7-10 correspond to dynamic mechanical analysis (DMA). The glass transition temperature (Property 6) and storage modulus in torsion mode at minus 25 °C, 25 °C, 50 °C, and 75 °C (Properties 7 to 10, respectively) were obtained by dynamic mechanical analysis (DMA) in accordance with ASTM D5279- 21 on an Advanced Rheometric Expansion System (ARES-G2) from TA Instruments equipped with liquid nitrogen environmental control and torsion rectangular fixtures. Rectangular samples were cut from the foam (described above at 5 mm thickness) and cut to dimensions of 45 mm length, and 12.8 mm width. The sample length was lined up axial to the torsional axis, and the DMA was performed in torsional mode. The temperature was increased from -50 °C to 150 °C at a ramp rate of 3 °C / min. The frequency of testing was 1 Hz at 0.05% torsional strain, with an axial tensile force of 0.098 N applied to keep sample taut, and at a data collection interval of 30 sec per point. The major output from the characterization identified were the storage modulus in shear modulus (G’) over the temperature range of test (Properties 7 to 10), and Tan δ value over the testing temperature with the peak value of it assigned as glass transition temperature (Tg in °C) (Property 6).

[0087] Property 11 corresponds to Elongation at break.

[0088] Property 12 corresponds to Ultimate tensile strength, also referred to as tensile strength.

[0089] Property 13 corresponds to Elastic modulus.

[0090] The Elongation at break (%), Ultimate tensile strength (MPa), and Elastic modulus (MPa) were determined utilizing foam (described above at 5 mm thickness) in accordance with ASTM D1708-06 on an MTS machine. The microtensile samples were punched in a microtensile dog-bone shape and conditioned for minimum of 24 hours before testing at 50% relative humidity (+ / - 10%) and 75 °F temperature (+ / - 5 °F).

[0091] Property 14 corresponds to density in g / cm3. Density was determined in accordance with ASTM D1622-08.

[0092] Property 15 corresponds to hardness. Hardness was determined utilizing a Durometer of Shore D scale in accordance with ASTM D2240, at approximately 2 min after demolding the foam.

Claims

Claims What is claimed is:

1. A rigid foam formulation comprising: a high hydroxyl number polyether polyol having an average hydroxyl number from 350 to 1,900 mg KOH / g and an average hydroxyl functionality from 1.5 to 8; a low hydroxyl number polyether polyol having an average hydroxyl number from 7 to 70 mg KOH / g and an average hydroxyl functionality from 1.5 to 8; ammonium polyphosphate; an alkaline earth metal salt; blowing agent; and an isocyanate.

2. The rigid foam formulation of claim 1, wherein: the high hydroxyl number polyether polyol is from 10 to 30 weight percent of the foam formulation based upon 100 weight percent of the foam formulation; the low hydroxyl number polyether polyol is from 10 to 30 weight percent of the foam formulation based upon 100 weight percent of the foam formulation; the ammonium polyphosphate is from 0.5 to 30 weight percent of the foam formulation based upon 100 weight percent of the foam formulation; the blowing agent is from 0.01 to 105 weight percent of the foam formulation based upon 100 weight percent of the foam formulation; the alkaline earth metal salt is from 0.5 to 20 weight percent of the foam formulation based upon 100 weight percent of the foam formulation; and the isocyanate is from 25 to 75 weight percent of the foam formulation based upon 100 weight percent of the foam formulation.

3. The rigid foam formulation of any one of claims 1-2, further comprising: a chain extender; a catalyst; and a surfactant.

4. The rigid foam formulation of claim 3, wherein: the chain extender is from 0.1 to 5 weight percent of the foam formulation based upon 100 weight percent of the foam formulation; the catalyst is from 0.01 to 5 weight percent of the foam formulation based upon 100 weight percent of the foam formulation; andthe surfactant is from 0.01 to 5 weight percent of the foam formulation based upon 100 weight percent of the foam formulation.

5. The rigid foam formulation of any one of claims 1-4, wherein the alkaline earth metal salt is calcium carbonate, magnesium carbonate, barium carbonate, or a combination thereof.

6. The rigid foam formulation of any one of claims 1-5, wherein the blowing agent is water.

7. The rigid foam formulation of any one of claims 1-6, wherein the high hydroxyl number polyether polyol is a glycerine alkoxylated polyether polyol and the low hydroxyl number polyether polyol is a difunctional polyether polyol.

8. A foam product formed by curing the rigid foam formulation of any one of claims 1-7, wherein the foam product has a density from 0.3 to 0.9 g / cm3determined according to ASTM D1622-08.

9. The foam product of claim 8, wherein the foam product provides a UL-94 vertical burn rating of V-0, V-1, or V-2.

10. A multilayer assembly that provides a UL-94 vertical burn rating of V-0, V-1, or V-2, wherein a layer of the foam product of any one of claims 8-9 is applied in an Electric vehicle (EV) battery assembly and a self-leveling layer of polyurethane product applied on top of the layer of the foam product.

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