Low viscosity polyurethane acrylate hybrid compositions for strong and tough products

Abstract

The polyurethane-acrylate hybrid composition can include a polyurethane phase and a polyacrylate phase, wherein the polyurethane phase comprises the reaction product of an isocyanate component comprising one or more isocyanate compounds and an isocyanate-reactive component comprising one or more polyether polyols, and the poly(meth)acrylate phase comprises the reaction product of one or more (meth)acrylate monomers having an acrylate functionality in the range of 2 to 8 and one or more initiators, wherein the (meth)acrylate monomers and initiators are independently present in at least one of the isocyanate component, the isocyanate-reactive component, or a third component introduced during combination of the isocyanate component and the isocyanate-reactive component, and the polyurethane phase and polyacrylate phase form an interpenetrating network. The method includes forming the polyacrylate hybrid composition and a composite containing the same.

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Embodiments relate to polyurethane-acrylate hybrid compositions containing an interpenetrating network of a polyurethane phase and a polyacrylate phase, and methods of using the same. [Background technology]

[0002] Introduction PU-based elastomers have found widespread application in many fields, but traditional means for increasing tensile strength are limited. Fillers often increase the tensile properties of PUs, but are also associated with undesirable increases in viscosity and elongation at break. Other approaches include the addition of plasticizers and impact modifiers, which can improve elongation and toughness in some systems, but offer a trade-off between reduced modulus and hardness at ambient and elevated temperatures. Additionally, plasticizers can leach out of the material during its lifetime (especially at elevated temperatures), which can generate volatile organic compounds and raise safety concerns. Therefore, the need for high strength (stiff and tough), high softening point (i.e., glass transition temperature or T g ), and options for PU-based materials with low viscosity during application are limited, particularly in applications such as electric vehicle (i.e., EV) battery potting / gap filling and EV battery tray insulation layers, and / or composites produced using pultrusion processes. Summary of the Invention

[0003]

[0003] Embodiments disclosed herein include polyurethane-acrylate hybrid compositions having a polyurethane phase and a polyacrylate phase, wherein the polyurethane phase comprises the reaction product of an isocyanate component comprising one or more isocyanate compounds and an isocyanate-reactive component comprising one or more polyether polyols, and the poly(meth)acrylate phase comprises the reaction product of one or more (meth)acrylate monomers having an acrylate functionality in the range of 2 to 8 and one or more initiators, wherein the (meth)acrylate monomers and initiators are independently present in at least one of the isocyanate component, the isocyanate-reactive component, or a third component introduced during combination of the isocyanate component and the isocyanate-reactive component, and the polyurethane phase and the polyacrylate phase form an interpenetrating network. Methods include forming polyacrylate hybrid compositions and composites containing the same.

[0004] In another aspect, embodiments disclosed herein include a method of preparing a polyurethane-acrylate hybrid composition, comprising combining an isocyanate component comprising one or more isocyanate compounds, an isocyanate-reactive component comprising one or more polyether polyols, and an optional third component to form a mixture, wherein one or more (meth)acrylate monomers having an acrylate functionality in the range of 2 to 8 and one or more initiators are independently present in at least one of the isocyanate component, the isocyanate-reactive component, or the optional third component; and reacting the mixture to form the polyurethane-acrylate hybrid composition.

[0005] In another aspect, embodiments disclosed herein include a method of preparing a composite article, comprising disposing on a substrate or extruding through a die chamber a polyurethane-acrylic hybrid composition prepared by combining an isocyanate component comprising one or more isocyanate compounds, an isocyanate-reactive component comprising one or more polyether polyols, an optional third component, and a reinforcing material to form a mixture, wherein one or more (meth)acrylate monomers having an acrylate functionality in the range of 2 to 8 and one or more initiators are independently present in at least one of the isocyanate component, the isocyanate-reactive component, or the optional third component; and curing the mixture to produce the composite article. DETAILED DESCRIPTION OF THE INVENTION

[0006] Embodiments relate to polyurethane (PU) acrylate hybrid polymer compositions containing an interpenetrating network of a polyurethane phase and a polyacrylate phase. The PU acrylate hybrid compositions can exhibit low viscosity (<600 cP) before cure and, upon cure, improved storage modulus and impact resistance. The method can include reacting an isocyanate component with an isocyanate-reactive component in the presence of orthogonal polymerization of a (meth)acrylate monomer with an initiator to produce the PU acrylate hybrid composition.

[0007] As used herein, the term "interpenetrating polymer network" (i.e., IPN) is intended to mean an intertwined network of two (or more) polymer phases obtained by simultaneous and / or sequential polymerization and / or crosslinking of two or more types of monomers to produce a mixed polymer product having single and / or multiple glass transition temperature ranges from two or more intertwined but independent crosslinked networks. Interpenetrating networks are distinguishable from mixtures of preformed polymer networks because they contain individual polymer phases that are at least partially interwoven on a molecular scale but are not covalently bonded to each other and cannot be separated without rupture and / or collapse and / or degradation. IPNs with two independent networks in the same material are also referred to in some literature as dual and / or double networks.

[0008] PU acrylate hybrid compositions can be prepared through orthogonal polymerization of each PU phase with a poly(meth)acrylate phase. The PU acrylate hybrid composition can be produced by reacting an isocyanate component with an isocyanate-reactive component, while the acrylate phase is produced through the reaction of one or more (meth)acrylate monomers with a free-radical initiator system. The (meth)acrylate monomers and free-radical initiators can be located in the isocyanate and / or isocyanate-reactive component, or can be combined as a third component when combining the isocyanate and isocyanate-reactive component. The (meth)acrylate monomers and free-radical initiator system can be combined in a single component or split into one or more components.

[0009] The PU phase in the PU acrylate hybrid composition can include an isocyanate component containing one or more isocyanate compounds, such as polymeric isocyanates, aromatic isocyanates, or carbodiimide-modified isocyanates. The isocyanate compounds can be monomers, oligomers, prepolymers, etc. The isocyanate component can include, for example, one or more isocyanate and / or polyisocyanate compounds. The isocyanate component can include an isocyanate compound having a nominal functionality of ≥ 1.5 or ≥ 2.0.

[0010] The isocyanate component can include an isocyanate compound having a number average molecular weight of 150 g / mol to 750 g / mol. In some cases, the isocyanate compound can have a number average molecular weight of as low as 150 g / mol, 200 g / mol, 250 g / mol, or 300 g / mol to as high as 350 g / mol, 400 g / mol, 450 g / mol, 500 g / mol, or 750 g / mol. Number average molecular weight values ​​reported herein are determined by end group analysis, gel permeation chromatography, and other methods known in the art. The isocyanate compound can be a monomer and / or polymer known in the art.

[0011] The isocyanate component may include one or more of aliphatic polyisocyanates, cycloaliphatic polyisocyanates, araliphatic polyisocyanates, aromatic polyisocyanates, and the like. Examples of isocyanates include, but are not limited to, polymethylene polyphenylisocyanate, toluene 2,4- / 2,6-diisocyanate (TDI), methylenediphenyl diisocyanate (MDI, including its isomers), polymeric and prepolymeric MDI, triisocyanatononane (TIN), naphthyl diisocyanate (NDI), 4,4'-diisocyanatodicyclohexyl-methane, 3-isocyanatomethyl-3,3,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), tetramethylene diisocyanate, hexamethylene diisocyanate, among others. diisocyanate (HDI), 2-methyl-pentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (THDI), dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 4,4'-diisocyanato-3,3'-dimethyl-dicyclohexylmethane, 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. In addition to the isocyanates mentioned above, partially modified polyisocyanates containing uretdione, isocyanurate, carbodiimide, uretonimine, allophanate or biuret structures, among others, and combinations thereof may also be utilized.

[0012] The isocyanate compound may include an isocyanate prepolymer resulting from the reaction of an isocyanate-reactive compound with a molar excess of an isocyanate compound or a polymeric isocyanate compound under conditions that do not cause gelation or solidification, and the isocyanate prepolymer may have a higher average isocyanate equivalent weight of >140 g / eq. Formation of an isocyanate prepolymer is known in the art and may include reacting (1) at least one isocyanate compound with (2) at least one polyol compound. The isocyanate prepolymer may be described by its isocyanate index, which is defined as the ratio of isocyanate groups to isocyanate-reactive groups (such as OH groups) multiplied by 100. The isocyanate prepolymers disclosed herein can have an isocyanate index (defined as the equivalents of isocyanate divided by the total equivalents of isocyanate-reactive hydrogen-containing materials multiplied by 100) in the ranges of 30 to 400, 40 to 300, or 40 to 200.

[0013] Examples of commercially available isocyanates include, but are not limited to, polyisocyanates available from The Dow Chemical Company under the trade names VORANATE™, VORATRON™, PAPI™, VORAFORCE™, and ISONATE™.

[0014] The PU acrylate hybrid composition may include an isocyanate component in a weight percent (wt%) in the range of 15 wt% to 80 wt%, 20 wt% to 80 wt%, or 20 wt% to 70 wt%.

[0015] The isocyanate-reactive component can include a polyol blend containing one or more polyether polyols, including mixtures of high and low molecular weight (MW) polyether polyols, one or more (meth)acrylate monomers, initiators, catalysts, surfactants, fillers, and other additives. The isocyanate-reactive component can have a viscosity of 600 cP or less, 500 cP or less, or within the range of 40 cP to 500 cP, according to ASTM D2983-21.

[0016] The isocyanate-reactive component can include one or more polyether polyols prepared by polyaddition of alkylene oxides, such as propylene oxide and / or ethylene oxide, onto a polyhydroxy-functional starter compound in the presence of a catalyst known in the art. The polyether polyols can be prepared from one or more starter compounds and one or more alkylene oxides, such as ethylene oxide, propylene oxide, and / or butylene oxide. The starter compounds can include molecules having 1 to 8 hydroxyl groups per molecule, such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, 1,4-butanediol, 1,6-hexanediol, bisphenol A, glycerol, trimethylolpropane, pentaerythritol, sugars and sugar alcohols such as sucrose and sorbitol. Polyether polyols may also include polyols reacted with polyethers formed from copolymers of alkylene oxides, including block copolymers and ethoxy and / or propoxy "capped" polyethers.

[0017] The polyether polyol may have a hydroxyl equivalent weight, defined as the weight average molecular weight of the polyol divided by the average number of hydroxyl groups or average hydroxyl functionality of the molecule, in the range of 30 Da to 5000 Da, or 30 Da to 4000 Da.

[0018] The polyether polyol may comprise a mixture of low MW and high MW polyether polyols, where "high MW" refers to polyether polyols having a number average molecular weight of 500 Da or greater and "low MW" refers to polyether polyols having a number average molecular weight of less than 500 Da. The high MW and low MW polyether polyols may be independently selected from polyether polyols having a hydroxyl functionality in the range of 1 to 8. The weight ratio of high MW:low MW polyether polyol may be in the range of 5:1 to 1:5, 5:1 to 1:1, 4:1 to 1:4, 3:1 to 1:3, or 3:1 to 1:1.

[0019] The isocyanate-reactive component may include at least one polyether polyol present in a weight percent (wt%) of the isocyanate-reactive component of 40 wt% to 95 wt%, 45 wt% to 95 wt%, or 50 wt% to 90 wt%. In formulations containing a mixture of high MW and low MW polyether polyols, the wt% ranges may apply to each type of polyol or to the combined total.

[0020] The isocyanate-reactive component may include one or more (meth)acrylate monomers having an unsaturated double bond functionality ranging from 2 to 8 and a number average molecular weight of 100 Da or greater. As used herein, the use of "(meth)" in conjunction with various acrylates or acrylate species indicates that the scope herein encompasses both acrylate and / or methacrylate variations of the referenced compound.

[0021] Acrylate and methacrylate monomers include (meth)acrylate-functionalized polyols and polyalkylene glycols (e.g., polyethylene glycol). Suitable (meth)acrylate monomers include ethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, nonanediol di(meth)acrylate, butylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, i.e., (PEG) di(meth)acrylate, dipropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, and the like. (Meth)acrylates, glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, tris(2-hydroxyl-ethyl)isocyanurate triacrylate, ditrimethylolpropane tetra(meth)acrylate, and di- or polyacrylates derived from alkoxylated polyols, such as propoxylated neopentyl glycol diacrylate or propoxylated glycerol triacrylate, neopentyl glycol di(meth)acrylate, combinations thereof, etc. Preferred reactive diluents are diacrylates, such as 1,6 hexanediol diacrylate, 1,9 nonanediol diacrylate, 1,4 butanediol acrylate, tricyclodecane dimethanol diacrylate, cyclohexane dimethanol diacrylate, cis / trans 1,3 / 1,4 cyclohexane dimethanol diacrylate, alkoxylated cyclohexane dimethanol diacrylate, tripropylene glycol diacrylate, etc. More preferred reactive diluents include propoxylated neopentyl glycol diacrylate, propoxylated glyceryl triacrylate, and tripropylene glycol diacrylate. In some cases, in addition to any of the above (meth)acrylate monomers, a monofunctional (meth)acrylate monomer and a monofunctional (meth)acrylate-functionalized polyol may be added.

[0022] The isocyanate-reactive component can include one or more acrylate monomers in a weight percent (wt%) ranging from 5 wt% to 90 wt%, or from 10 wt% to 80 wt%. The poly(meth)acrylate phase prepared from the (meth)acrylate monomers and initiator is present in a weight percent (wt%) of the PU-acrylate hybrid composition in a range from 2 wt% to 50 wt%, 2.5 wt% to 50 wt%, or 5 wt% to 50 wt%.

[0023] The PU acrylate hybrid composition may include one or more initiators (e.g., free radical initiators) added to the isocyanate, the isocyanate-reactive component, or as a third component introduced during the combination of the isocyanate and the isocyanate-reactive component. Initiators include, but are not limited to, peroxides, persulfides, peroxycarbonates, peroxyboric acid, quinone azo compounds, or other suitable radical initiators capable of initiating the cure of double bond-containing compounds. The initiators may be active or activatable by oxidation-reduction, thermal initiation, or photoinitiation, or any combination thereof. Suitable initiators include azo compounds such as 2,2-azobisisobutyronitrile (AIBN), or peroxides such as tert-butyl peroxybenzoate, butyl 4,4-di(tert-butylperoxy)valerate, di-tert-amyl peroxide, dicumyl peroxide, di(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di(tert-butylperoxyl)hexane, tert-butyl Examples of commercially available initiators include cumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxyl)hexyne-3, di-tert-butyl peroxide, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane, isopropyl cumyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumyl hydroperoxide, tert-butyl hydroperoxide, etc., or ketones such as benzophenone, camphorquinone, thioxanthone, etc. Examples of commercially available initiators are LUPEROX® DI, LUPEROX® 10, and LUPEROX® P from Arkema, and IRGACURE® 819, IRGACURE® 651, and IRGACURE® 819 from Ciba, among other commercially available radical initiators and / or generators.Additionally, one or more photosensitive radical initiators that undergo either a Norrish Type I or Norrish Type II reaction mechanism can be used in either the isocyanate and / or isocyanate-reactive component and / or as a separate component. The polyurethane-acrylate hybrid composition can include one or more initiators in weight percent (wt%) of the isocyanate and / or isocyanate-reactive component ranging from 0.1 wt% to 6 wt%, or from 0.1 wt% to 5 wt%.

[0024] The isocyanate-reactive component may include one or more catalysts for promoting polyurethane polymerization to produce the PU-acrylate hybrid composition. The catalysts may be used individually or as catalyst packages containing multiple catalysts, such as gelling catalysts, blowing catalysts, and trimerization catalysts. Gelling catalysts and blowing catalysts may be distinguished by their tendency to favor either the urethane (gel) reaction in the case of gelling catalysts or the urea (blow) reaction in the case of blowing catalysts. A trimerization catalyst may be utilized to promote the isocyanurate-forming reaction in the composition. The catalyst package may also be added as a separate stream to the reaction mixture of the isocyanate and the isocyanate-reactive composition.

[0025] Gelling catalysts include organometallic compounds, cyclic tertiary amines and / or long-chain amines (e.g., containing several nitrogen atoms), and combinations thereof. Organometallic compounds include organotin compounds such as tin(II) salts of organic carboxylic acids, such as tin(II) diacetate, tin(II) dioctanoate, tin(II) diethylhexanoate, and tin(II) dilaurate, and dialkyltin(IV) salts of organic carboxylic acids, such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, and dioctyltin diacetate. Bismuth salts of organic carboxylic acids can also be used as gelling catalysts, such as bismuth octanoate. Cyclic tertiary amines and / or long-chain amines include dimethylbenzylamine, triethylenediamine, and combinations thereof. Examples of commercially available gelling catalysts are POLYCAT® 8, DABCO® 33-LV, and DABCO® T-12 from Evonik, among other commercially available gelling catalysts.

[0026] The blowing catalyst may include, among others, bis-(2-dimethylaminoethyl)ether; pentamethyldiethylenetriamine, triethylamine, tributylamine, N,N-dimethylaminopropylamine, dimethylethanolamine, N,N,N',N'-tetra-methylethylenediamine, and combinations thereof. One example of a commercially available blowing catalyst is POLYCAT® 5 from Evonik, among other commercially available blowing catalysts.

[0027] The trimerization catalyst may include any such catalyst known in the art. Examples of trimerization catalysts include N,N',N"-tris(3-dimethylaminopropyl)hexahydro-s-triazine, N,N-dimethylcyclohexylamine, 1,3,5-tris(N,N-dimethylaminopropyl)-s-hexahydrotriazine, [2,4,6-tris(dimethylaminomethyl)phenol], potassium acetate, potassium octanoate, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, alkali metal hydroxides such as sodium hydroxide, alkali metal alkoxides such as sodium methoxide and potassium isopropoxide; and alkali metal salts of long-chain fatty acids having 10 carbon atoms to 20 carbon atoms, and combinations thereof. Some commercially available trimerization catalysts include, for example, DABCO® TMR-2, DABCO® TMR-20, DABCO® TMR-30, DABCO® TMR-7, DABCO® K, among other commercially available trimerization catalysts. 2097; DABCO® K15, POLYCAT® 41, and POLYCAT® 46, each available from Evonik.

[0028] Catalysts may include "latent catalysts" or "delayed catalysts," which are defined as catalytic compounds that have low catalytic activity or are relatively inactive at ambient temperatures and become more catalytically active upon heating, such as by dissociation, decoordination, ring-opening, ionization, or tautomerization, to catalyze at least one of the chemical reactions involved in the fabrication of PU foam. Ambient temperatures may range from 15°C to 32°C, and room temperature is often about 23°C.

[0029] Latent / delayed catalysts can be gelling, blowing, and / or trimerization type catalysts, depending on their function in the foaming process. Latent catalysts are often a subset of tertiary amine gelling catalysts (e.g., delayed action tertiary amines based on 1,8-diazabicyclo[5.4.0]undec-7-ene), which include acid salts, phenol salts, or complexes of tertiary amine catalysts, where the acid or phenol is often a carboxylic acid or phenolic species, such as, but not limited to, formic acid, acetic acid, propionic acid, 2-ethylhexanoic acid, phenoxyacetic acid, gluconic acid, tartaric acid, citric acid, phenol, nonylphenol, diisopropylphenol, and mixtures thereof. Some commercially available latent catalysts that can be used include, for example, DABCO® TMR-30, POLYCAT® SA2 LE, POLYCAT® SA-1 / 10, DABCO® 8154, NIAX™ A-107, NIAX™ C-31, NIAX™ C-225, JEFFCAT™ ZF-54, JEFFCAT™ LED-204, and mixtures thereof.

[0030] The catalyst or catalyst package may be present in the PU acrylate hybrid composition in a weight percent (wt%) ranging from 0.1 wt% to 10 wt%, or from 1 wt% to 7 wt%. Optionally, the catalyst package may be added to the isocyanate component and / or isocyanate-reactive component in an amount sufficient to provide a mixture having the corresponding weight percentages above.

[0031] The PU acrylate hybrid composition may include one or more fillers and / or inorganic reinforcing materials, including glass fibers, fibers, ceramics, silica, calcium carbonate, kaolin, talc, alumina, alumina trihydrate (ATH), hollow particulates (e.g., glass, ceramic, polymer), etc. In some cases, the reinforcing material includes any one or more of glass fibers, carbon nanotubes, carbon fibers, polyester fibers, natural fibers, aramid fibers, nylon fibers, basalt fibers, boron fibers, silicon carbide fibers, asbestos fibers, whiskers, hard particles, metal fibers, surface-functionalized derivatives thereof, etc.

[0032] Fillers and / or inorganic reinforcing agents can be surface functionalized with a treating agent to modify their hydrophobicity or hydrophilicity or to introduce one or more functional groups, such as alkyl, hydroxyl, amine, vinyl, allyl, acrylate, methacrylate, hydrosilyl (i.e., SiH), etc. The treating agent can vary depending on the nature of the filler or inorganic reinforcing agent. For example, a silica surface can be modified with a silane treating agent to incorporate functional groups that react with or modify the compatibility of fillers in PU-acrylate hybrid formulations.

[0033] One or more fillers can be added in weight percent (wt%) of the composition ranging from 0 wt% to 85 wt%, or 5 wt% to 80 wt%, or 10 wt% to 75 wt%. In some cases, the filler can be added to the isocyanate component and / or the isocyanate-reactive component in an amount sufficient to provide a mixture having the corresponding weight percentages described above. In some cases, an article can be formed from the PU acrylate composition by combining the isocyanate and the isocyanate-reactive component, dispensing the combined mixture into a reinforcing material, and processing the resulting composite by a suitable process (e.g., pultrusion, molding, etc.).

[0034] The PU-acrylate hybrid composition may include one or more silicone or organic antifoaming agents added in weight percent (wt%) of the polyurethane-acrylate hybrid composition in the range of 0.05 wt% to 5 wt%, 0.1 wt% to 1.5 wt%, or 0.1 wt% to 1 wt%.

[0035] The isocyanate-reactive component may also contain one or more additives including blowing agents, surfactants, crosslinkers, plasticizers, fillers, smoke suppressants, fragrances, toughening agents, dyes, colorants, pigments, preservatives, odor maskers, physical blowing agents, chemical blowing agents, flame retardants, internal mold release agents, biocides, antioxidants, UV stabilizers, antistatic agents, moisture scavengers, thixotropic agents, adhesion promoters, cell openers, and the like.

[0036] Although the formulation components are disclosed individually, it is contemplated that the component elements (e.g., isocyanates or compounds in the isocyanate-reactive component) may be included, excluded, or combined in any manner or subcombination using the concentration ranges and nested subranges described above.

[0037] The PU acrylate hybrid composition can generally be formed by combining an isocyanate component and an isocyanate-reactive component to form a mixture by a suitable method (e.g., mixing, pouring), while the (meth)acrylate phase-forming compounds (i.e., (meth)acrylate monomers, initiators) are independently present in the isocyanate or the isocyanate-reactive component, or both. The (meth)acrylate phase-forming compounds may also be added as a third component at or during mixing of the isocyanate and the isocyanate-reactive component and prior to polyurethane formation.

[0038] The PU acrylate hybrid composition can be used in any suitable process for fabricating articles and composites, including molding, injection, vacuum infusion, pultrusion, etc. In one method, the PU acrylate hybrid composition can be prepared by combining an isocyanate component, an isocyanate-reactive component, a (meth)acrylate monomer and an initiator to form a mixture, processing the mixture in a mold to produce a molded article, and demolding the molded article.

[0039] A method of preparing a polyurethane-acrylate hybrid composition may include combining an isocyanate component including one or more isocyanate compounds, an isocyanate-reactive component including one or more polyether polyols, and an optional third component to form a mixture, wherein one or more (meth)acrylate monomers having an acrylate functionality in the range of 2 to 8, and one or more initiators are independently present in one or more of the isocyanate component, the isocyanate-reactive component, or the optional third component, and reacting the mixture to form the polyurethane-acrylate hybrid composition.

[0040] The PU acrylate hybrid composition can be used to prepare composite parts. To prepare composite parts, the polyurethane-poly(meth)acrylate reactive composition is mixed with or injected into a reinforcement material, for example, by vacuum-assisted resin transfer molding (VARTM) and / or resin transfer molding (RTM). In some cases, a method for preparing a composite article can include disposing a polyurethane acrylic hybrid composition onto a substrate or extruding it through a die chamber, the polyurethane acrylic hybrid composition being prepared by combining an isocyanate component including one or more isocyanate compounds, an isocyanate-reactive component including one or more polyether polyols, an optional third component, and a reinforcement material to form a mixture, wherein one or more (meth)acrylate monomers having an acrylate functionality in the range of 2 to 8 and one or more initiators are independently present in at least one of the isocyanate component, the isocyanate-reactive component, or the optional third component, and curing the mixture to produce a composite article.

[0041] Composite articles prepared using the PU-acrylate hybrid compositions of the present invention may include one or more reinforcing materials in weight percent (wt%) in the ranges of 1 wt% to 90 wt%, 30 wt% to 90 wt%, 40 wt% to 85 wt%, or 40 wt% to 80 wt%.

[0042] Composite articles prepared using the PU acrylate hybrid compositions of the present invention may further comprise one or more core materials to facilitate molding and lightweighting of the composite, including polystyrene foam, polyester PET foam, polyimide PMI foam, polyvinyl chloride foam, metal foam, cellulose, wood such as balsa wood, and the like.

[0043] The polyurethane-acrylate hybrid composition can be used to produce articles and composites with excellent mechanical properties, such as improved impact resistance and modulus, high heat distortion temperature, high tensile and flexural strength, high fatigue resistance, high ductility, and low shrinkage. The articles and composites can be used in automotive and / or stationary storage applications, such as potting and / or encapsulation (fully or partially) of electric vehicle (i.e., EV) batteries, gap fillers, thermal barriers, and EV battery tray insulation layers, as well as composites manufactured using a pultrusion process. The articles and composites can also be used to manufacture wind turbine blades, wind turbine nacelle housings, marine propeller blades, boat hulls, automotive interior and exterior decorative parts, automotive bodies, radomes, machine structural members, decorative and structural components for buildings and bridges, and the like.

[0044] Composite articles prepared using the PU compositions of the present invention may include one or more reinforcing materials in weight percent (wt%) in the ranges of 1 wt% to 90 wt%, 30 wt% to 90 wt%, 40 wt% to 85 wt%, or 40 wt% to 80 wt%. [Example]

[0045] The following examples are provided to illustrate embodiments of the present invention, but are not intended to limit its scope. Table 1 provides the materials used in the following examples.

[0046] [Table 1]

[0047] Example 1: Properties of Polyurethane-Acrylate Hybrid Compositions In this example, samples of the present invention containing a polyurethane-acrylate hybrid composition were analyzed for physical properties compared to a comparative example containing polyurethane only.

[0048] The sample formulations are shown in Table 2 below. The samples were prepared by blending the formulation ingredients in a DAC 600.1 FVZ-K speed mixer in the proportions specified in Table 2. All units are in grams unless otherwise specified. The A-side and B-side ingredients were prepared separately and mixed. The mixture was poured into a mold and held at 23°C until tack-free. The plaque was then removed from the mold and the specimen shape was cut accordingly. The specimens were then post-cured at 100°C for 1 hour to ensure the formation of the polyurethane and acrylate IPN.

[0049] [Table 2]

[0050] The sample formulations were then tested for a number of characteristics and performance properties (Property Nos. I-XI).

[0051] Viscosity (Property No. I): The viscosity of the pre-compounded B-side part for each formulation (except CE3 and IE3) was measured using a Brookfield DV-II+Pro viscometer. The rotation speed and torque were adjusted for each sample's viscosity range at 25°C according to ASTM D2983. For the pre-compounded B-side of sample CE3, a TA Instruments AR 2000 rheometer with a 54 mm cone-plate geometry and a 450 micron gap was used for viscosity measurements according to ASTM D4440-15. The sample temperature was held at 25°C and the applied shear rate was 1 / sec. For the pre-compounded B-side of sample IE3, the kinematic viscosity was measured at 25°C using an Ostwald viscometer using ASTM D445.

[0052] The elongation at break (Property No. II), ultimate tensile strength (Property No. III), and tensile modulus (Property No. IV) were determined on an MTS machine using the ASTM D1708-18 standard. After molding (and aging at ASTM conditions for a minimum of 2 days), the cured specimens were approximately 3 mm thick for testing. Microtensile specimens were further cut or punched into a dogbone shape.

[0053] Shear moduli (Property Nos. V-VII) and glass transition temperatures (Property No. VIII) in torsion mode were obtained by dynamic mechanical analysis (DMA) using ASTM D5279-21 on a TA Instruments Advanced Rheometric Expansion System (ARES-G2) equipped with liquid nitrogen environmental control and a torsion rectangle fixture. Rectangular specimens were cut from pottant plaques prepared in metal molds (A and B) according to the procedure described above, with a thickness of 2 mm and cut to dimensions of 45 mm long and 12.8 mm wide. DMA was performed in torsion mode, with the specimen length aligned axially with the torsion axis. The temperature was ramped from -70 °C to 200 °C at a rate of 3 °C / min. The test frequency was 1 Hz at 0.05% torsional strain, with an axial tension of 0.098 N applied to hold the specimen taut, and a data collection interval of 30 s per point. The primary outputs from the characterization were the storage modulus at shear (G') over the temperature range and the peak of the tangent curve at the glass transition temperature (T g ) was assigned.

[0054] Izod impact test (IX) was determined by molding the specimens to a length of 45 mm, a width of 12.7 mm, and a thickness of 3 mm. The specimens were notched in the center with a notch length of 2.54 mm. A CEAST Notchvis automatic notcher (POR-TL-090) was used for notching. Impact resistance was measured at 23°C and 50% relative humidity according to ASTM D256 (Method for Determining Izod Pendulum Impact Resistance of Plastics) using a Model 92T equipped with a Model 892 Impact Display System.

[0055] [Table 3]

[0056] The comparative examples (CE1-3) have B-side viscosities (Property No. I) of >600 cP, and the modulus (Property No. V) of the pure PU elastomer (CE1) improves with the corresponding increase in viscosity due to the use of fillers (CE2-3). IE1-IE3 have relatively low viscosities (<600 cP) and exhibit improved storage moduli (Property Nos. V-VII). While modulus can be improved by increasing the isocyanate content, the inclusion of methacrylate monomers IE1-IE3 provided increases of 6-40% over CE1 (and 80-140% over CE2 and CE3) at similar or lower isocyanate concentrations. Additionally, impact strength is increased approximately two-fold over PU. Impact strength for IE1 and IE2 is 2.1 kJ / m for CE1-CE3. 2 4.2 kJ / m, respectively, compared to 2 and 3.9 kJ / m 2 is.

[0057] While the foregoing is directed to exemplary embodiments, other and further embodiments may be devised without departing from the basic scope thereof, which scope is determined by the claims that follow.

Claims

1. A polyurethane-acrylate hybrid composition comprising a polyurethane phase and a polyacrylate phase, the polyurethane phase an isocyanate component comprising one or more isocyanate compounds; and an isocyanate-reactive component comprising one or more polyether polyols; The poly(meth)acrylate phase is comprising the reaction product of one or more (meth)acrylate monomers having an acrylate functionality in the range of 2 to 8 and one or more initiators; the (meth)acrylate monomer and initiator are independently present in at least one of the isocyanate component, the isocyanate-reactive component, or a third component introduced during combination of the isocyanate component and the isocyanate-reactive component; A polyurethane-acrylate hybrid composition, wherein the polyurethane phase and the polyacrylate phase form an interpenetrating network.

2. 10. The composition of claim 1, wherein the poly(meth)acrylate phase is present in a weight percent (wt%) of the PU-acrylate hybrid composition in the range of 5 wt% to 45 wt%.

3. 10. The composition of claim 1, wherein the polyether polyol comprises a mixture of a high MW polyether polyol and a low MW polyether polyol.

4. 10. The composition of claim 1, wherein the polyether polyol comprises a mixture of high MW and low MW polyether polyols in a weight ratio of from 5:1 to 1:

1.

5. 10. The composition of claim 1, wherein the one or more polyether polyols have a hydroxyl equivalent weight in the range of 30 Da to 4000 Da.

6. The composition of claim 1 further comprising a reinforcing material in a weight percent (wt%) of from 5 wt% to 80 wt%.

7. 10. The composition of claim 1, wherein the isocyanate-reactive component has a viscosity of 600 cP or less, 500 cP or less, according to ASTM D2983-21 (or ASTM D445).

8. 10. An article prepared from the polyurethane-acrylate hybrid composition of claim 1.

9. 1. A method for preparing a polyurethane-acrylate hybrid composition, comprising: an isocyanate component comprising one or more isocyanate compounds; an isocyanate-reactive component comprising one or more polyether polyols; and an optional third component to form a mixture, forming one or more (meth)acrylate monomers having an acrylate functionality in the range of 2 to 8, and one or more initiators, independently, present in at least one of the isocyanate component, the isocyanate-reactive component, or the optional third component; and reacting the mixture to form the polyurethane-acrylate hybrid composition.

10. 1. A method of preparing a composite article, comprising: an isocyanate component comprising one or more isocyanate compounds; an isocyanate-reactive component comprising one or more polyether polyols; an optional third component; and and a reinforcing material, and forming a mixture, the polyurethane acrylic hybrid composition is placed on a substrate or extruded through a die chamber, disposing or extruding one or more (meth)acrylate monomers having an acrylate functionality in the range of 2 to 8, and one or more initiators, independently, in at least one of the isocyanate component, the isocyanate-reactive component, or the optional third component; and curing the mixture to form the composite article.

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