Curable compositions, articles made therefrom, and methods of making and using the same

Abstract

A curable composition comprising: a polyol component comprising one or more polyols; a functionalized butadiene component; and filler particles; wherein the curable composition has a thermal conductivity of at least 3.0 W / (mK) after curing. The filler particles include aluminum trihydroxide (ATH) and a smoke suppressant selected from zinc hydroxystannate (ZHS), zinc stannate, calcium stannate, calcium hydroxystannate, and any combination thereof.

Description

Technical Field

[0001] This invention relates generally to curable compositions. Curable compositions can be used, for example, as thermally conductive gap fillers, which can be suitable for use in electronic applications such as battery assemblies. Background Technology

[0002] Curable compositions that can be used as thermally conductive gap fillers have been described, for example, in EP 3352290, CN 101235277 and WO 2011 / 019719. Attached Figure Description

[0003] Figure 1 illustrates components of an exemplary battery module according to some embodiments of the present disclosure.

[0004] Figure 2 It shows the corresponding Figure 1 The assembled battery module.

[0005] Figure 3 The components of an exemplary battery subcell according to some embodiments of the present disclosure are shown. Detailed Implementation

[0006] Thermal management plays a crucial role in many electronic applications, such as electric vehicle (EV) battery packs, power electronics, electronic packaging, LEDs, solar cells, and power grids. Certain thermally conductive materials (e.g., adhesives) may be an attractive choice for these applications due to their good electrical insulation properties, feasibility in processing integrated components or complex geometries, and good conformability / wetting properties to different surfaces, particularly their ability to effectively dissipate heat while maintaining good adhesion to different substrates used for assembly.

[0007] Regarding applications in EV battery modules, one such application utilizing thermally conductive materials is the use of gap fillers—thermal sealants—which remove heat from the battery module and toward the cooling plate. Generally, requirements for gap filler applications include high thermal conductivity, good lap shear bond strength, good tensile strength, good elongation at break for toughness, and good damping properties; low viscosity / high flowability (in both parts of a two-part system) before curing; flame retardancy (e.g., UL94 V0); low density; and reprocessability should the battery module need to be replaced during the EV's lifespan. To achieve high thermal conductivity, a large amount of inorganic thermally conductive filler is typically added to the composition. However, high filler loadings have detrimental effects on adhesion, toughness, damping properties, viscosity, and density.

[0008] Many existing compositions used in EV heat gap filler applications are based on polyurethane curing chemistry. While these polyurethane-based materials exhibit many beneficial properties at high filler loadings, they exhibit poor stability at high temperatures, and the isocyanates used in such products raise safety concerns.

[0009] Siloxane-containing compositions are also used in EV thermal adhesive gap filler applications. However, such materials cure slowly and are incompatible with many components in batteries, such as foam, polyester, and aluminum.

[0010] Alternatives to polyurethane and siloxane-based compositions, such as flexible epoxy-amine and epoxy-thiol compositions, have also been developed. These compositions have proven unsuitable, at least due to insufficient reprocessability, flowability, or elongation properties at high filler loadings. Furthermore, many of these compositions are incompatible with certain common, low-cost flame-retardant filler materials.

[0011] Other alternatives to polyurethane and silicone-based compositions include those formulated by blending polyol components, functionalized butadiene components, and conductive fillers such as alumina and aluminum trihydrate (ATH). While such compositions have been shown to achieve thermal conductivity of 2 W / (m*K), the inclusion of additional fillers is undesirable if higher thermal conductivity is required, as alumina results in undesirable flame retardancy and abrasion properties, and ATH results in higher-than-desirable viscosity (which should be low enough to allow for rapid pumping and dispensing rates and low compressibility during use), particularly in resins with polar functional groups. Therefore, curable compositions possessing the aforementioned desired properties while also achieving a thermal conductivity of at least 3 W / mK, sufficiently low viscosity and abrasion, and V0 flame retardancy are desirable.

[0012] To address the aforementioned performance and safety issues, a curable composition has been discovered that provides a good balance of the desired properties and a thermal conductivity of at least 3 W / mK. More specifically, in addition to a thermal conductivity of at least 3 W / mK, good lap shear bond strength, tensile strength, elongation at break, and damping properties, the curable composition of this disclosure also exhibits reprocessability over a wide temperature range, flowability, low density, and compatibility with a wide range of filler materials. Furthermore, the curable composition of this disclosure is not based on polyurethane curing chemicals and does not contain silicone. Moreover, the curable composition can be formed from natural / plant-based raw materials.

[0013] As used in this article:

[0014] The term "room temperature" refers to a temperature between 22°C and 25°C.

[0015] The terms "cured" and "curable" refer to polymers that are linked together by covalent chemical bonds, typically through crosslinking molecules or groups, to form a network polymer. Therefore, in this disclosure, the terms "cured" and "crosslinked" are used interchangeably. Generally, cured or crosslinked polymers are characterized by insolubility, but can be swollen in the presence of a suitable solvent.

[0016] The term "unfilled composition" refers to all components of the composition except for the thermally conductive filler component.

[0017] The term "main chain" refers to the main continuous chain of a polymer.

[0018] The term "alkyl" refers to a monovalent group that is a free radical of an alkane and includes straight-chain, branched, cyclic, and bicyclic alkyl groups, as well as combinations thereof, including both unsubstituted and substituted alkyl groups. Unless otherwise specified, alkyl groups typically contain 1 to 30 carbon atoms. In some embodiments, alkyl groups contain 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, or 1 to 3 carbon atoms. Examples of "alkyl" groups include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, isobutyl, tert-butyl, isopropyl, n-octyl, n-heptyl, ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornyl, and the like.

[0019] The term "alkylene" refers to a divalent radical of an alkane and includes straight-chain groups, branched groups, cyclic groups, bicyclic groups, or combinations thereof. Unless otherwise specified, alkylene groups typically have 1 to 30 carbon atoms. In some embodiments, alkylene groups have 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Examples of "alkylene" groups include methylene, ethylene, 1,3-propylene, 1,2-propylene, 1,4-butylene, 1,4-cyclohexylene, and 1,4-cyclohexyldimethylene.

[0020] The term "alkenyl" refers to an unsaturated branched, straight-chain, or cyclic hydrocarbon group having at least one carbon-carbon double bond. This group may be in a cis or trans conformation surrounding the double bond. Typical alkenyl groups include, but are not limited to, vinyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, and the like. Unless otherwise specified, alkenyl groups typically have 1 to 30 carbon atoms. In some embodiments, the alkenyl group has 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms.

[0021] The term "aromatic" refers to C3-C40, suitably C3-C30 aromatic groups, including carbocyclic aromatic groups, as well as heterocyclic aromatic groups containing one or more heteroatoms O, N or S, and fused-ring systems containing one or more of these aromatic groups fused together.

[0022] The term "aryl" refers to a monovalent group that is aromatic and optionally has a carbon ring. An aryl group has at least one aromatic ring. Any additional rings may be unsaturated, partially saturated, saturated, or aromatic. Optionally, the aromatic ring may have one or more additional carbon rings fused to the aromatic ring. Unless otherwise specified, an aryl group typically contains 6 to 30 carbon atoms. In some embodiments, the aryl group contains 6 to 20 carbon atoms, 6 to 18 carbon atoms, 6 to 16 carbon atoms, 6 to 12 carbon atoms, or 6 to 10 carbon atoms. Examples of aryl groups include phenyl, naphthyl, biphenyl, phenanthryl, and anthracene.

[0023] The term "arylene" refers to a divalent group that is aromatic and optionally has a carbocyclic ring. An arylene group has at least one aromatic ring. Optionally, the aromatic ring may have one or more additional carbocyclic rings fused to the aromatic ring. Any additional rings may be unsaturated, partially saturated, or saturated. Unless otherwise specified, arylene groups typically have 6 to 20 carbon atoms, 6 to 18 carbon atoms, 6 to 16 carbon atoms, 6 to 12 carbon atoms, or 6 to 10 carbon atoms.

[0024] The term "aralkyl" refers to a monovalent group of an alkyl group substituted with an aryl group (e.g., as in a benzyl group). The term "alkylaryl" refers to a monovalent group of an aryl group substituted with an alkyl group (e.g., as in a tolyl group). Unless otherwise specified, for both groups, the alkyl moiety typically has 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms, and the aryl moiety typically has 6 to 20 carbon atoms, 6 to 18 carbon atoms, 6 to 16 carbon atoms, 6 to 12 carbon atoms, or 6 to 10 carbon atoms.

[0025] The term (meth)acrylate refers to acrylate or methacrylate.

[0026] Reference numerals used repeatedly in this specification are intended to indicate the same or similar features or elements of this disclosure. As used herein, the phrase “between” applied to numerical ranges includes the endpoints of the range, unless otherwise specified. Numerical ranges expressed by endpoints include all numbers within the range (e.g., 1 to 5 including 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within the range.

[0027] In some embodiments, this disclosure provides a filler-filled, thermally conductive, curable composition formulated by blending at least a polyol component, a functionalized butadiene component, and a filler comprising aluminum trioxide (ATH) and a smoke suppressant selected from zinc hydroxystannate (ZHS), zinc stannate, calcium stannate, calcium hydroxystannate, or combinations thereof.

[0028] In some embodiments, the curable composition may comprise a polyol component comprising one or more polyols, such as one or more polyols containing two or more primary or secondary aliphatic hydroxyl groups (i.e., hydroxyl groups directly bonded to non-aromatic carbon atoms). The hydroxyl groups of the polyol may be terminal or may be side groups of a polymer or copolymer. In some embodiments, the polyol may comprise any polyol compatible with the functionalized butadiene component (i.e., without phase separation during mixing).

[0029] In some embodiments, the polyol may include monomeric polyols. Representative examples of available monomeric polyols include alkylene glycols (e.g., 1,2-ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-ethyl-1,6-hexanediol, 1,4-cyclohexanediol, 1,18-dihydroxyoctadecane, and 3-chloro-1,2-propanediol), polyhydroxy alkanes (e.g., glycerol, trimethylolethane, pentaerythritol, and sorbitol), and other polyhydroxy compounds (such as castor oil).

[0030] In some embodiments, the polyol may include one or more dimer diols, one or more trimer triols, or combinations thereof.

[0031] In some embodiments, a suitable dimer glycol may contain at least one alkyl or alkenyl group and is characterized by having two hydroxyl groups. The dimer glycol may be saturated or unsaturated. The dimer glycol may have a relatively high molecular weight and is composed of a mixture of various high molecular weight or relatively high molecular weight diols comprising various ratios. The component structure may be acyclic, cyclic (e.g., monocyclic or bicyclic), or aromatic. In some embodiments, a suitable commercially available dimer glycol may be obtained from Croda under the trade name Pripol 2033.

[0032] In some embodiments, a suitable teryl glycerol may contain at least one alkyl or alkenyl group and is characterized by having three hydroxyl groups. The teryl glycerol may be saturated or unsaturated. The teryl glycerol may have a relatively high molecular weight and is composed of a mixture of various high molecular weight or relatively high molecular weight triols in various ratios. The component structure may be acyclic, cyclic (e.g., monocyclic or bicyclic), or aromatic. In some embodiments, a suitable commercially available teryl glycerol may be obtained from DowDuPont under the trade name Tone 0301 polyol.

[0033] In some embodiments, other high molecular weight diols used for the polyol may include polybutadiene diol and hydrogenated polybutadiene diol, such as G-1000 and GI-1000 from Nippon Soda Co., Ltd., and Krasol F3000 and Krasol F3100 from Total.

[0034] In some embodiments, the number-average molecular weight of the polyol may be between 100 g / mol and 3000 g / mol, between 250 g / mol and 2000 g / mol, or between 400 g / mol and 1000 g / mol. In some embodiments, the number of carbon atoms in the polyol may be between 12 and 100, between 20 and 100, between 30 and 100, between 12 and 80, between 20 and 80, between 30 and 80, between 12 and 60, between 20 and 60, or between 30 and 60.

[0035] In some embodiments, the polyol component may further include one or more monofunctional alcohols. In some embodiments, suitable monofunctional alcohols may include alkyl, alkenyl, alkynyl, aromatic, heteroaromatic, branched, unbranched, substituted, and unsubstituted alcohols, alkoxylated products of alkyl alcohols, alkyl ester alcohols, and mixtures thereof. In some embodiments, the monofunctional alcohol may include alkyl alcohols having 4 to 18 carbon atoms, 8 to 16 carbon atoms, or 12 to 16 carbon atoms, and a molecular weight of 74 g / mol to 1000 g / mol or 130 g / mol to 500 g / mol.

[0036] In some embodiments, the functionalized butadiene component may include any functionalized butadiene capable of reacting with the polyol of the polyol component. In some embodiments, the functionalized butadiene component may have the following general structural formula:

[0037]

[0038] Where a is 30 to 150 or 30 to 120; and n is 1 to 30 or 2 to 15.

[0039] In some embodiments, the functionalized butadiene component may consist of a mixture of functionalized butadienes having a variety of molecular weights.

[0040] In some embodiments, the functionalized butadiene component may include maleated polyalkyladiene, maleated liquid rubber, maleated liquid isoprene, liquid polyfarnescene, maleated styrene-butadiene rubber (SBR), or combinations thereof. In some embodiments, the functionalized butadiene component may comprise or consist substantially of maleated polybutadiene (such as, for example, maleated butadiene from the Ricon series available from Cray Valley).

[0041] In some embodiments, the curable compositions of this disclosure may comprise reactive and non-reactive diluents compatible with the functionalized butadiene component. Examples of reactive diluents may include maleated soybean oil, dodecynyl succinic anhydride, octenyl succinic anhydride, and octadecynyl succinic anhydride. Examples of non-reactive diluents include liquid butadiene (e.g., Ricon 130, Ricon 131, and Ricon 134 from Cray Valley), soybean oil, hydrogenated petroleum distillates, or other vegetable oils compatible with the functionalized butadiene component.

[0042] In some embodiments, the curable compositions of this disclosure may comprise one or more resins capable of reacting with an acid / ester formed when an alcohol (of polyol or monofunctional alcohol) reacts with a functionalized butadiene component (e.g., maleic anhydride group). Suitable such resins may include epoxidized vegetable oils, epoxidized fatty acid esters, or epoxidized α-olefins and epoxidized polybutenes. Commercially available examples of these resins include Vikoflex 5075, Vikoflex 7170, Vikoflex 7190, Vikolox 16, and Vikopol 24, all purchased from Arkema.

[0043] In some embodiments, the resin may be incorporated into the curable composition by either or both of the polyol and the functionalized butadiene component. Alternatively, the resin may be incorporated into the curable composition after the polyol and the functionalized butadiene component have been mixed. In any case, the resin may be present in the curable composition in an amount between 0.1% and 10% by weight, between 0.5% and 5% by weight, or between 1% and 3% by weight, based on the total weight of the filled curable composition.

[0044] In some embodiments, the curable composition of this disclosure may comprise one or more filler particles. The filler particles may comprise at least aluminum trioxide (ATH) and a smoke suppressant selected from zinc hydroxystannate (ZHS), zinc stannate, calcium stannate, calcium hydroxystannate, or combinations thereof. Surprisingly, the combination of ATH and this smoke suppressant has been found to result in high thermal conductivity and reduced viscosity and density, while also allowing for a UL-94V0 flame retardant rating.

[0045] In some embodiments, the smoke suppressant may contain ZHS or consist substantially of ZHS. In some embodiments, the curable composition may contain at least 0.5 wt%, at least 2 wt%, at least 10 wt%, or at least 20 wt% of the smoke suppressant or ZHS based on the total weight of the filled curable composition; and at least 0.5 wt%, at least 2 wt%, at least 11 wt%, or at least 22 wt% of the smoke suppressant or ZHS based on the total weight of the filler particles in the curable composition.

[0046] In some embodiments, the curable composition may contain at least 10 wt%, at least 20 wt%, at least 30 wt%, or at least 45 wt% of ATH based on the total weight of the filled curable composition; and at least 11 wt%, at least 22 wt%, at least 34 wt%, or at least 51 wt% of ATH based on the total weight of the filler particles in the curable composition.

[0047] In some embodiments, the filler particles may also comprise any known thermally conductive filler particles, although electrically insulating fillers may be preferred when considering breakdown voltage. Suitable electrically insulating and thermally conductive filler particles may comprise ceramics, such as oxides, hydroxides, hydroxyl oxides, silicates, borides, carbides, and nitrides. Suitable ceramic fillers include, for example, silicon oxide (e.g., fused silica), alumina, boron nitride, silicon carbide, and beryllium oxide. Other thermally conductive filler particles include carbon-based materials (such as graphite) and metals (such as aluminum, copper, gold, and silver). In some embodiments, the filler particles may also comprise at least alumina. In some embodiments, the curable composition may comprise at least 40 wt%, at least 50 wt%, at least 60 wt%, or at least 70 wt% of alumina based on the total weight of the filled curable composition; and or at least 45 wt%, at least 56 wt%, at least 68 wt%, or at least 79 wt% of alumina based on the total weight of the filler particles in the curable composition.

[0048] Thermally conductive filler particles can be obtained in various shapes, such as spherical, irregular, plate-like, and needle-like. In some applications, thermal conductivity through the plane may be important. Therefore, in some embodiments, typically symmetrical (e.g., spherical or hemispherical) fillers can be used. To facilitate dispersion and increase filler loading, in some embodiments, the thermally conductive filler may be surface-treated or coated. Generally, any known surface treatment and coating can be suitable, including those based on silanes, titanates, zirconates, aluminates, and organic acid chemicals. In some embodiments, the thermally conductive filler particles may include silane-surface-treated particles (i.e., particles with surface-bonded organosilanes). For powder handling purposes, many fillers can be used as polycrystalline agglomerates or aggregates with or without a binder. To facilitate high thermal conductivity formulations, some embodiments may include mixtures of particles and agglomerates of various sizes, as well as mixtures thereof.

[0049] The curable compositions disclosed herein may comprise at least 25 wt%, at least 35 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, or at least 90 wt% of filler particles (including smoke suppressants, ATH, alumina, or any other filler particles) based on the total weight of the filled curable composition. In some embodiments, the filler loading may be between 25 wt% and 95 wt%, between 35 wt% and 90 wt%, between 55 wt% and 85 wt%, or between 70 wt% and 85 wt% based on the total weight of the filled curable composition.

[0050] In some embodiments, the curable composition according to this disclosure may contain one or more dispersants. Generally, dispersants can act as stabilizers for inorganic filler particles in the composition, which, without a dispersant, may aggregate, thus adversely affecting the benefits of the particles in the composition. Suitable dispersants may depend on the specific characteristics and surface chemistry of the filler. In some embodiments, suitable dispersants according to this disclosure may contain at least binding groups and compatible segments. The binding groups may be ionicly bonded to the particle surface. Examples of binding groups for alumina particles include phosphoric acid, phosphonic acid, sulfonic acid, carboxylic acid, and amines. In some embodiments, the dispersant may be present in the curable composition in an amount between 0.1 wt% and 10 wt%, between 0.1 wt% and 5 wt%, between 0.5 wt% and 3 wt%, or between 0.5 wt% and 2 wt%, based on the total weight of the filled curable composition. In some embodiments, the dispersant may be premixed with the inorganic filler before being incorporated into the curable composition. This premixing may facilitate the filled system to behave like a Newtonian fluid or to achieve shear-thinning effect behavior.

[0051] In some embodiments, the curable composition may contain one or more plasticizers. As mentioned above, low viscosity and sufficient flowability are desirable properties for thermally conductive materials used in gap filler applications. In this regard, the curable compositions of this disclosure may include one or more plasticizers to promote lower viscosity and improved flowability. However, it should be noted that adding a plasticizer alone is insufficient to overcome the limitations of known gap filler compositions addressed by this disclosure. That is, in known curable compositions for gap filler applications, if the filler particle load is increased to achieve a thermal conductivity of at least 3 W / mK, the resulting viscosity and flowability are unacceptable. Furthermore, the minimum amount of plasticizer required to achieve acceptable levels of viscosity and flowability makes it impossible to maintain a thermal conductivity of at least 3 W / mK.

[0052] In some embodiments, suitable plasticizers may include natural oils containing hydroxyl functional groups (also known as natural oil polyols or biopolyols), which can be used as reactive diluents compatible with the main resin component (e.g., dimer diols). These natural polyols may include castor oil or processed castor oil-based polyols, soybean oil polyols, linseed oil polyols, and other vegetable oil-based polyols with various degrees of hydroxyl functionality. Suitable plasticizers also include monofunctional alcohols of different chain lengths.

[0053] In some embodiments, suitable plasticizers include non-reactive diluents such as soybean oil, linseed oil, other natural oils, and hydrogenated petroleum distillates. The non-reactive diluent may be present in the curable composition in amounts between 0.1% and 10% by weight, between 0.1% and 5% by weight, between 0.5% and 3% by weight, or between 0.5% and 2% by weight, based on the total weight of the filled curable composition.

[0054] In some embodiments, the curable composition may contain one or more rheology modifiers.

[0055] In some embodiments, the curable composition according to this disclosure may contain one or more catalysts. Generally, catalysts can accelerate the curing of the curable composition.

[0056] In some embodiments, the curable composition may comprise an amine catalyst that catalyzes the reaction between maleated butadiene and a polyol. The amine catalyst may be any compound containing one to four basic nitrogen atoms with lone pairs of electrons. The amine catalyst may comprise a primary amine group, a secondary amine group, a tertiary amine group, or a combination thereof. The nitrogen atom in the amine catalyst may be bonded to an alkyl group, an aryl group, an arylalkylene group, an alkylarylalkylene group, an alkylarylalkylene group, or a combination thereof. The amine catalyst may also be a cyclic amine, which may include one or more rings and may be aromatic or non-aromatic (e.g., saturated or unsaturated). One or more nitrogen atoms in the amine may be part of a carbon-nitrogen double bond. While in some embodiments the amine catalyst comprises only carbon-nitrogen, nitrogen-hydrogen, carbon-carbon, and carbon-hydrogen bonds, in other embodiments the amine catalyst may comprise other functional groups (e.g., hydroxyl or ether groups). However, those skilled in the art will understand that compounds containing nitrogen atoms bonded to carbonyl groups are amides rather than amines and have different chemical properties than amines. Amine catalysts may contain carbon atoms bonded to more than one nitrogen atom. Therefore, amine catalysts may be guanidine or amidine. Those skilled in the art will understand that the lone pair electrons on one or more nitrogen atoms of an amine catalyst distinguish it from quaternary ammonium compounds, which have a permanent positive charge regardless of pH. Amine catalysts may include combinations of one or more amines as described above. In some embodiments, the amine catalyst includes at least one of tertiary amines, amidine, imidazole, or guanidine.

[0057] Examples of available amine catalysts include propylamine, butylamine, pentylamine, hexylamine, triethylamine, tri-(2-ethylhexyl)amine (TEHA), dimethylethanolamine, benzyldimethylamine, dimethylaniline, dimethylundecylamine, tribenzylamine, triphenylamine, tetramethylguanidine (TMG), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO), quinine ring, diphenylguanidine (DPG), dimethylaminomethylphenol, tris(dimethylaminomethyl)phenol, tris(dimethylaminomethyl)phenol tris(2-ethylhexanoate), dicyandiamide (DICY), and imidazoles (e.g., imidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole) and combinations thereof. In some embodiments, the amine catalyst comprises at least one of tetramethylguanidine, diphenylguanidine, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]undec-7-ene or 1,5-diazabicyclo[4.3.0]non-5-ene.

[0058] The compositions according to this disclosure typically have open and curing times, making them suitable for assembling battery modules without requiring heating to above ambient conditions for curing.

[0059] For some applications, increasing the open time of the compositions disclosed herein may be useful. To increase the open time, in some embodiments, at least a portion of the amine catalyst is a potential amine or an amine phase-separated from the composition at ambient temperature. The phase-separated second amine may exist as a solid, present in a solid adduct, or be separated within a solid in a composition in which the reactive component is typically liquid.

[0060] In some embodiments, at least a portion of the amine is a solid in the composition. In these embodiments, the solid is insoluble in the composition at ambient temperature but soluble in the composition at high temperatures (e.g., at least 50°C, 60°C, 70°C, 75°C, 80°C, 90°C, 95°C, or 100°C). In some embodiments, the amine catalyst comprises dicyandiamide (DICY). In some embodiments, the amine catalyst comprises an adduct of an amine and an epoxy resin. The adduct may comprise any of the amines described above and any of the epoxy resins described above. Suitable adducts of amines and epoxy resins are commercially available, for example, under the trade name “EPIKURE” from Hansen Corporation, Columbus, Ohio, and under the trade name “AJICURE” from Ajinomoto Fine-Techno Co., Inc., Kawasaki, Japan.

[0061] In some embodiments, at least a portion of the amine catalyst is segregated within the solid in the composition. Such amine catalysts can be considered encapsulated and can be prepared using any of a variety of microencapsulation techniques, such as coagulation, interfacial addition and condensation, emulsion polymerization, microfluidic polymerization, reverse micelle polymerization, air suspension, centrifugal extrusion, spray drying, granulation, coating, other methods, and any combination thereof. The amine catalyst may be contained in a single cavity or reservoir within the solid, or may be contained in multiple cavities within the solid. The loading of the amine catalyst can be 5% to 90%, 10% to 90%, or 30% to 90% based on the total weight of the amine catalyst and the solid. In these embodiments, the amine catalyst segregates within the solid at ambient temperature, but is released into the composition at high temperatures (e.g., at least 50°C, 60°C, 70°C, 75°C, 80°C, 90°C, 95°C, or 100°C) when the solid is at least partially melted. The time required to at least partially melt a solid can be up to 5 minutes, 4 minutes, 3 minutes, 2 minutes, or 1 minute.

[0062] In some embodiments, the catalyst may include Lewis acids, such as SnCl4 or p-toluenesulfonic acid.

[0063] In some embodiments, the curable composition of this disclosure may be provided as a two-part composition (e.g., packaged), wherein the first part comprises the aforementioned polyol component, and the second part comprises the aforementioned functionalized butadiene component. Other components of the curable composition (e.g., fillers, crosslinking agents, dispersants, catalysts, etc.) may be included in one or both of the first and second parts. This disclosure also provides a dispenser comprising a first chamber and a second chamber. The first chamber comprises the first part, and the second chamber comprises the second part.

[0064] In addition to the additives discussed above, one or both of Part I and Part II may contain other additives. These may include, for example, any one or all of the following: antioxidants / stabilizers, colorants, abrasive particles, thermal degradation stabilizers, light stabilizers, conductive particles, tackifiers, leveling agents, base agents, matting agents, inert fillers, binders, foaming agents, fungicides, bactericides, surfactants, and other additives known to those skilled in the art. If such additives are present, they shall be added in an amount effective for their intended use.

[0065] In some embodiments, the polyol component (without any filler) may be present in the curable composition of this disclosure in an amount between 0.1 wt% and 20 wt%, between 0.5 wt% and 10 wt%, between 1 wt% and 8 wt%, between 1.5 wt% and 5 wt%, or between 2 wt% and 4 wt%, based on the total weight of the filled curable composition. In some embodiments, the polyol component (without any filler) may be present in the curable composition of this disclosure in an amount of at least 0.1 wt%, at least 0.5 wt%, at least 1 wt%, at least 1.5 wt%, at least 2 wt%, or at least 2.5 wt%, based on the total weight of the filled curable composition. In some embodiments, the functionalized butadiene component (without any filler) may be present in the curable composition of this disclosure in an amount between 1 wt% and 40 wt%, between 2 wt% and 30 wt%, between 3 wt% and 20 wt%, or between 4 wt% and 10 wt%, based on the total weight of the filled curable composition. In some embodiments, the functionalized butadiene component (containing no filler) may be present in the curable composition of this disclosure in an amount of at least 1 wt%, at least 2 wt%, at least 3 wt%, or at least 4 wt%, based on the total weight of the filled curable composition.

[0066] In some embodiments, the polyol and functionalized butadiene components may be present in the curable composition based on the stoichiometric ratio of the functional groups of the respective components.

[0067] In some embodiments, after curing (i.e., the cured composition is the reaction product of the curable composition), the curable compositions of this disclosure exhibit thermal, mechanical, and rheological properties that make the compositions particularly suitable for use as thermally conductive gap fillers. It is believed that even at thermal conductivity of 3 W / mK or higher, the curable compositions of this disclosure provide optimal blending for tensile strength, elongation at break, and lap shear strength for certain EV battery component applications, as well as providing strong reprocessability and flowability at normal operating temperatures, and are compatible with certain common low-cost flame-retardant fillers (e.g., ATH).

[0068] In some embodiments, after curing, the curable composition of this disclosure may have a thermal conductivity of at least 3.0 W / mK, at least 3.2 W / mK, at least 3.3 W / mK, at least 3.4 W / mK, or at least 3.5 W / mK. For the purposes of this application, the thermal conductivity value is determined by first measuring the diffusivity according to ASTM E1461-13, "Standard Test Method for Thermal Diffusivity by the Flash Method," and then calculating the thermal conductivity from the measured thermal diffusivity, heat capacity, and density measurements according to the following formula:

[0069] k = α·cp·ρ, where k is the thermal conductivity in W / (m K), and α is the thermal conductivity in mm. 2 The thermal diffusivity is expressed as / s, cp as the specific heat capacity is expressed as J / kg, and ρ as the thermal diffusivity is expressed as g / cm³. 3 The density is expressed in units. The thermal diffusivity of the sample can be measured directly and relative to a standard, according to ASTM E1461-13, using Netzsch LFA 467 "HYPERFLASH". Sample density can be measured using a geometric method, while specific heat capacity can be measured using differential scanning calorimetry.

[0070] In some embodiments, the cured composition may have the following elongation at break: for a fully cured system, at a tensile rate between 0.8 mm / min and 1.5 mm / min, in the range of 0.1% to 200%, 0.5% to 175%, 1% to 160%, or 5% to 160% (for the purposes of this application, the elongation at break values ​​are measured according to ASTM D638-03 "Standard Test Method for Tensile Properties of Plastics"); or for a fully cured system, at a tensile rate between 0.8 mm / min and 1.5 mm / min, at least 5%, at least 5.5%, at least 6%, at least 7%, at least 10%, at least 50%, at least 100%, or at least 150%.

[0071] In some embodiments, the cured composition may have the following lap shear strength on a bare aluminum substrate: for a fully cured system, at 1 N / mm². 2 Up to 30 N / mm 2 2N / mm 2 Up to 30 N / mm 2 1N / mm 2 Up to 25 N / mm 24N / mm 2 Up to 20 N / mm 2 6N / mm 2 Up to 20 N / mm 2 2N / mm 2 Up to 16 N / mm 2 or 3N / mm 2 Up to 8N / mm 2 Within the range (for the purposes of this application, the lap shear strength values ​​were measured according to EN 1465 Adhesives - Determination of tensile lap-shear strength of bonded assemblies) on an untreated aluminum substrate (i.e., an aluminum substrate without surface treatment or coating other than a natural oxide layer). Additionally, it should be noted that the cured composition exhibited adhesive failure (rather than cohesive failure) during the lap shear strength measurement, indicating that the cured composition readily peels off from the aluminum substrate.

[0072] In some embodiments, the cured composition may have the following tensile strength: for a fully cured system, at a tensile rate between 1% strain / min and 10% strain / min, 0.5 N / mm². 2 Up to 16 N / mm 2 1N / mm 2 Up to 10 N / mm 2 or 2N / mm 2 Up to 8N / mm 2 Within the range (for the purposes of this application, the tensile strength value is measured according to EN ISO527-2 tensile test).

[0073] In some embodiments, the cured compositions are sufficiently "reprocessable" in that they can be used to adhere subsequent battery assemblies in cases where the original battery needs to be replaced during the life of the EV. In this respect, the cured compositions may have a peel strength of at least 0.01 N / mm on an aluminum substrate and at least 0.01 N / mm on a PET substrate. For the purposes of this application, the peel strength was determined according to ASTM D1876.

[0074] In some embodiments, within 10 minutes or less after mixing the polyol component with the functionalized butadiene component, the viscosity of the at least partially cured composition, measured at 25°C, is in the range of 100 poise to 50,000 poise, and the viscosity measured at 60°C is in the range of 100 poise to 50,000 poise. Further regarding viscosity, the viscosity of the polyol component, measured at 25°C (before mixing with the functionalized butadiene component and containing any fillers or other additives), is in the range of 100 poise to 100,000 poise or 1 poise to 10 poise, and at 60°C, it is in the range of 10 poise to 10,000 poise; and the viscosity of the functionalized butadiene component, measured at 25°C (before mixing with the polyol component and containing any fillers or other additives), is in the range of 100 poise to 100,000 poise or 1 poise to 10 poise, and at 60°C, it is in the range of 10 poise to 10,000 poise. For the purposes of this application, viscosity values ​​were measured using a 40 mm parallel plate geometry and a shear scan in the range of 0.001–10 s⁻¹, with viscosity reported at a shear rate of 2 s⁻¹.

[0075] In some embodiments, the curing rate of the curable composition may be in the range of 10 minutes to 240 hours, 30 minutes to 72 hours, or 1 hour to 24 hours for complete curing at room temperature; or in the range of 10 minutes to 6 hours, 10 minutes to 3 hours, or 30 minutes to 60 minutes for complete curing at 100°C; or in the range of 1 hour to 24 hours for complete curing at room temperature; or in the range of 10 minutes to 6 hours, 10 minutes to 3 hours, or 30 minutes to 60 minutes for complete curing at 120°C.

[0076] In some embodiments, the green strength curing rate of the composition at room temperature may be less than 10 minutes, less than 11 minutes, less than 15 minutes, less than 20 minutes, or less than 30 minutes. For the purposes of this application, the green strength curing rate can be approximated based on the lap shear strength accumulation rate. In this regard, in some embodiments, after curing at room temperature for 10 minutes, the composition may have an lap shear strength of at least 0.2 MPa, at least 0.3 MPa, at least 0.5 MPa, or at least 0.8 MPa. For the purposes of this application, the lap shear strength value is measured according to EN 1465.

[0077] In some embodiments, the combination of ATH as a filler material and a smoke suppressant can promote a reduced density of the cured composition (which is important for applications such as EV gap fillers where minimizing weight is desired). In this regard, the curable compositions of this disclosure can have a density of less than 2.5 g / cc, less than 2.4 g / cc, less than 2.3 g / cc, or less than 2.2 g / cc after curing.

[0078] In some embodiments, after curing, the curable composition of this disclosure may have a UL-94 flame retardancy rating of V0.

[0079] This disclosure also relates to methods for preparing the above-described curable compositions. In some embodiments, the curable compositions of this disclosure can be prepared by first mixing the components of the polyol component (including fillers and any additives) and then separately mixing the components of the functionalized butadiene component (including fillers and any additives). The components of both the polyol component and the functionalized butadiene component can be mixed using any conventional mixing technique (including the use of a rapid mixer). In embodiments where a dispersant is used, the dispersant can be premixed with the filler before being incorporated into the composition. Next, the polyol and functionalized butadiene components can be mixed using any conventional mixing technique to form the curable composition.

[0080] In some embodiments, the curable compositions of this disclosure can be cured without the use of catalysts or other curing agents. Generally, the curable compositions can be cured under typical application conditions, such as at room temperature, without the need for elevated temperatures or photochemical radiation (e.g., ultraviolet light). In some embodiments, the first curable composition is cured at a temperature not exceeding room temperature. In some embodiments, flash heating (e.g., IR light) can be used.

[0081] In some embodiments, the curable composition of this disclosure can be provided as a two-part composition. Generally, the two components of the two-part composition can be mixed first and then applied to the substrate to be bonded. After mixing, the two-part composition can achieve the desired processing strength and ultimately the desired final strength. The application of the curable composition can be performed, for example, by dispensing the curable composition from a dispenser including a first chamber, a second chamber, and a mixing tip, wherein the first chamber contains a first portion, the second chamber contains a second portion, and the first and second chambers are coupled to the mixing tip to allow the first and second portions to flow through the mixing tip.

[0082] The curable compositions disclosed herein can be used in coatings, molded articles, adhesives (including structural adhesives and semi-structural adhesives), magnetic media, filled or reinforced composites, sealant compounds and filling compounds, casting compounds and molding compounds, potting compounds and encapsulating compounds, impregnation compounds and coating compounds, conductive adhesives for electronic devices, protective coatings for electronic devices, as primers or adhesion promoters, and other applications known to those skilled in the art. In some embodiments, this disclosure provides an article comprising a substrate on which a cured coating of the curable composition is having been applied.

[0083] In some embodiments, the curable composition can be used as a structural adhesive, i.e., the curable composition is capable of bonding a first substrate to a second substrate after curing. Generally, the bond strength (e.g., peel strength, lap shear strength, or impact strength) of a structural adhesive continues to improve after the initial curing time. In some embodiments, this disclosure provides an article comprising a first substrate, a second substrate, and a cured composition disposed between the first substrate and the second substrate and adhering the first substrate to the second substrate, wherein the cured composition is a reaction product of a curable composition according to any of the curable compositions of this disclosure. In some embodiments, the first substrate and / or the second substrate can be at least one of metal, ceramic, and polymer (e.g., thermoplastic).

[0084] The curable composition can be coated onto a substrate with a usable thickness ranging from 5 micrometers to 10,000 micrometers, 25 micrometers to 10,000 micrometers, 100 micrometers to 5,000 micrometers, or 250 micrometers to 1,000 micrometers. The usable substrate can have any properties and composition and can be inorganic or organic. Representative examples of usable substrates include ceramics, siliceous substrates including glass, metals (e.g., aluminum or steel), natural and artificial stone, woven and nonwoven products, polymeric materials including thermoplastic and thermosetting polymers (such as poly(methyl methacrylate), polycarbonate, polystyrene, styrene copolymers such as styrene-acrylonitrile copolymers, polyesters, polyethylene terephthalate), siloxanes, paints (such as those based on acrylic resins), powder coatings (such as polyurethane or hybrid powder coatings), and wood; as well as composites of the above materials.

[0085] In another aspect, this disclosure provides a coated article comprising a metal substrate having a coating of an uncured, partially cured, or fully cured curable composition on at least one surface of the metal substrate. If the substrate has two main surfaces, the coating may be applied to one or both main surfaces of the metal substrate and may include additional layers such as an adhesive layer, a bonding layer, a protective layer, and a topcoat layer. The metal substrate may be, for example, at least one of the inner and outer surfaces of a pipe, container, conduit, rod, profiled article, sheet, or tube.

[0086] In some embodiments, this disclosure also relates to a battery module comprising the uncured, partially cured, or fully cured curable composition of this disclosure. During assembly, representative components of the battery module are... Figure 1 As shown in the image, and the assembled battery module is in Figure 2As shown in the diagram, the battery module 50 can be formed by positioning a plurality of battery cells 10 on a first substrate 20. Generally, any known battery cell can be used, including, for example, rigid prismatic cells or pouch cells. The number, size, and position of the cells associated with a particular battery module can be adjusted to meet specific design and performance requirements. The construction and design of the substrate are well known, and any substrate suitable for the intended application (typically a metal substrate made of aluminum or steel) can be used.

[0087] Battery cell 10 can be connected to first substrate 20 via a first layer 30 of a first curable composition according to any one of the embodiments of this disclosure. The first layer 30 of the curable composition can provide primary thermal management in which the battery cell is assembled in a battery module. Since a voltage difference (e.g., up to 2.3 volts) may exist between the battery cell and the first substrate, breakdown voltage can be an important safety feature of this layer. Therefore, in some embodiments, a ceramic-like electrically insulating filler (typically alumina and boron nitride) can preferably be used in the curable composition.

[0088] In some embodiments, layer 30 may include a discontinuous pattern of a first curable composition applied to a first surface 22 of the first substrate 20, such as Figure 1 As shown. For example, a material pattern for the desired layout of the battery cells can be applied (e.g., robotically) to the surface of a substrate. In some embodiments, the first layer can be formed as a coating of the first curable composition covering all or substantially all of the first surface of the first substrate. In another embodiment, the first layer can be formed by applying the curable composition directly to the battery cells and then mounting them to the first surface of the first substrate.

[0089] In some embodiments, the curable composition may need to accommodate dimensional variations of up to 2 mm, up to 4 mm, or even greater. Therefore, in some embodiments, the first layer of the first curable composition may be at least 0.05 mm thick, for example, at least 0.1 mm, or even at least 0.5 mm thick. Depending on the electrical properties of the material, higher breakdown voltages may require thicker layers, for example, in some embodiments, at least 1 mm, at least 2 mm, or even at least 3 mm thick. Generally, to maximize heat conduction through the curable composition and minimize cost, the curable composition layer should be as thin as possible while still ensuring good contact with the heat sink. Therefore, in some embodiments, the thickness of the first layer is no greater than 5 mm, for example, no greater than 4 mm or even no greater than 2 mm.

[0090] As the first curable composition cures, the battery cells are held more securely in place. When curing is complete, the battery cells are finally fixed in their intended positions, such as... Figure 2 As shown. Additional components (e.g., belt 40) can be used to secure the units for transport and further processing.

[0091] Generally, it is desirable for the curable composition to cure under typical application conditions, such as under conditions that do not require elevated temperatures or photochemical radiation (e.g., ultraviolet light). In some embodiments, the first curable composition cures at room temperature or at a temperature not exceeding 30°C (e.g., not exceeding 25°C, or even not exceeding 20°C).

[0092] In some implementations, the curing time is no longer than 60 minutes, for example, no longer than 40 minutes or even no longer than 20 minutes. While very rapid curing (e.g., less than 5 minutes or even less than 1 minute) may be suitable for some applications, in some implementations, an open time of at least 5 minutes (e.g., at least 10 minutes or even at least 15 minutes) may be required to allow time for cell positioning and repositioning. Generally, it is desirable to achieve the desired curing time without using expensive catalysts such as platinum.

[0093] like Figure 3 As shown, multiple battery modules 50 (such as those related to...) Figure 1 and Figure 2 The examples and descriptions illustrate the assembly to form battery sub-cells 100. The number, size, and position of modules associated with a particular battery sub-cell can be adjusted to meet specific design and performance requirements. The construction and design of the second substrate are known, and any substrate suitable for the intended application (typically a metal substrate) can be used.

[0094] Each battery module 50 can be positioned on and attached to the second substrate 120 via a second layer 130 of a curable composition according to any of the embodiments of the present disclosure.

[0095] The second layer 130 of the second curable composition may be positioned on the second surface 24 of the first substrate 20 (see...). Figure 1 and Figure 2 The second curable composition is located between the first surface 122 of the second substrate 120 and the second curable composition. The second curable composition can provide a second level of thermal management, in which case the battery module is assembled into battery sub-cells. At this level, breakdown voltage may not be a requirement. Therefore, in some embodiments, conductive fillers, such as graphite and metal fillers, may be used alone or in combination with electrically insulating fillers such as ceramics.

[0096] In some embodiments, the second layer 130 may be formed as a coating covering all or substantially all of the second curable composition on the first surface 122 of the second substrate 120, such as Figure 3 As shown. In some embodiments, the second layer may include a discontinuous pattern of a second curable composition applied to the surface of the second substrate. For example, a material pattern corresponding to the desired layout of the battery module may be applied to the surface of the second substrate (e.g., robotically applied). In an alternative embodiment, the second layer may be applied to the second surface 24 of the first substrate 20 (see... Figure 1 and Figure 2 The second curable composition is applied directly, and then the module is mounted onto the first surface 122 of the second substrate 120 to form the second layer.

[0097] The assembled battery sub-cells can be combined to form other structures. For example, as is known, battery modules can be combined with other components (e.g., battery control units) to form battery systems, such as those used in electric vehicles. In some embodiments, additional layers of the curable composition according to this disclosure can be used to assemble such battery systems. For example, in some embodiments, thermally conductive gap fillers according to this disclosure can be used to mount and aid in cooling the battery control unit.

[0098] Additional Implementation Plan

[0099] 1. A curable composition comprising: a polyol component comprising one or more polyols; a functionalized butadiene component; and filler particles, wherein the filler particles comprise ATH and a smoke suppressant, and the filler particles are present in an amount of at least 20% by weight based on the total weight of the curable composition. The curable composition has a thermal conductivity of at least 3.0 W / (mK) after curing. The filler particles may comprise ZHS, zinc stannate, calcium stannate, calcium hydroxystannate, and any combination thereof.

[0100] 2. The curable composition according to embodiment 1, wherein the smoke suppressant is present in the curable composition in an amount of at least 0.5% by weight based on the total weight of the filled curable composition.

[0101] 3. The curable composition according to any one of the foregoing embodiments, wherein the smoke suppressant comprises ZHS.

[0102] 4. The curable composition according to any one of the foregoing embodiments, wherein ATH is present in the curable composition in an amount of at least 10% by weight based on the total weight of the filled curable composition.

[0103] 5. The curable composition according to any one of the foregoing embodiments, wherein the filler particles further comprise alumina.

[0104] 6. The curable composition according to any one of the foregoing embodiments, wherein the curable composition has a density of less than 2.5 g / cc after curing.

[0105] 7. The curable composition according to any one of the foregoing embodiments, wherein the curable composition has a UL-94 flame retardancy rating of V0 after curing.

[0106] 8. The curable composition according to any one of the foregoing embodiments, wherein the polyol component further comprises one or more monofunctional alcohols.

[0107] 9. The curable composition according to any one of the foregoing embodiments, wherein the polyol component comprises a polyol having a number-average molecular weight between 100 g / mol and 3000 g / mol.

[0108] 10. The curable composition according to any one of the foregoing embodiments, wherein the polyol is present in the curable composition in an amount between 0.5% by weight and 30% by weight based on the total weight of the curable composition.

[0109] 11. The curable composition according to any one of the foregoing embodiments, wherein the functionalized butadiene component comprises maleated polyalkyldiene, maleated liquid rubber, maleated liquid isoprene, liquid polyfarnesene, or maleated styrene-butadiene rubber.

[0110] 12. The curable composition according to any one of the foregoing embodiments, wherein the functionalized butadiene component comprises maleated polybutadiene.

[0111] 13. The curable composition according to any one of the foregoing embodiments, the curable composition further comprising a resin capable of reacting with an acid / ester formed when the alcohol group of the polyol reacts with the functionalized butadiene component.

[0112] 14. The curable composition according to embodiment 13, wherein the resin comprises epoxidized vegetable oil, epoxidized fatty acid ester, epoxidized α-olefin, or epoxidized polybutene.

[0113] 15. The curable composition according to any one of embodiments 13 to 14, wherein the resin is present in the curable composition in an amount between 0.5% by weight and 70% by weight based on the total weight of the curable composition.

[0114] 16. The curable composition according to any one of the foregoing embodiments, wherein the curable composition further comprises an amine catalyst.

[0115] 17. The curable composition according to any one of the foregoing embodiments, wherein the curable composition has an elongation at break of at least 5% after curing.

[0116] 18. The curable composition according to any one of the foregoing embodiments, wherein the curable composition, after curing, has a curing strength of 0.1 N / mm on a bare aluminum substrate. 2 Up to 30 N / mm 2 The lap shear strength within the range.

[0117] 19. The curable composition according to any one of the foregoing embodiments, wherein the curable composition, after curing, has a curing strength of 0.5 N / mm². 2 Up to 30 N / mm 2 Tensile strength within the range.

[0118] 20. The curable composition according to any one of the foregoing embodiments, wherein the curable composition has a peel strength of at least 0.01 N / mm on an aluminum substrate after curing.

[0119] 21. The curable composition according to any one of the foregoing embodiments, wherein the curable composition has a viscosity of 100 poise to 50,000 poise as measured at room temperature within 10 minutes of mixing the polyol component, the functionalized butadiene component and the filler particles.

[0120] 22. An article comprising a cured composition, wherein the cured composition is a reaction product of a curable composition according to any one of embodiments 1 to 21.

[0121] 23. The article of embodiment 22, wherein the cured composition has a thickness between 5 micrometers and 10,000 micrometers.

[0122] 24. The article of any one of embodiments 22 to 23, the article of which further comprises a substrate having a surface, wherein the cured composition is disposed on the surface of the substrate.

[0123] 25. The article of manufacture according to embodiment 24, wherein the substrate is a metal substrate.

[0124] 26. An article comprising a first substrate, a second substrate, and a cured composition disposed between the first substrate and the second substrate and adhering the first substrate to the second substrate, wherein the cured composition is a reaction product of a curable composition according to any one of embodiments 1 to 21.

[0125] 27. A battery module comprising a plurality of battery cells connected to a first substrate via a first layer of a curable composition according to any one of embodiments 1 to 21.

[0126] 28. A method of manufacturing a battery module, the method comprising: applying a first layer of a curable composition according to any one of embodiments 1 to 21 to a first surface of a first substrate, attaching a plurality of battery cells to the first layer to connect the battery cells to the first substrate, and curing the curable composition.

[0127] Example

[0128] The objectives and advantages of this disclosure are further illustrated by the following comparative and exemplary embodiments. Unless otherwise stated, all parts, percentages, ratios, etc., in the embodiments and the remainder of this specification are by weight.

[0129]

[0130]

[0131] Test methods

[0132] Thermal conductivity testing methods

[0133] Tests were performed according to ASTM D5470. Thermal conductivity was measured using a thermal interface material tester from Analysis Tech, Wakefield, Massachusetts. 1.5 mm thick film samples were prepared by applying the curable composition to a standard release liner using a benchtop coater and curing the composition at room temperature for 24 hours under constant temperature (25°C) and humidity (50% RH). Three 1.25-inch (3.2 cm) diameter discs were punched from the film. Thermal conductivity was measured at room temperature in 10% compression mode. The resistance-to-thickness ratio was measured on one, two, and three subsequently stacked discs to obtain thermal conductivity. The reported mean and standard deviation are based on results from four replicates.

[0134] Density testing methods

[0135] Tests were performed according to ASTM D792. The density of the cured composition was measured using a 3cm x 3cm cube of cured film cut from a 1.5mm thick film (as described in the Thermal Conductivity Test Method). Density measurements were performed at room temperature using an MS204S balance with a Density Kit MS-DNY-43, purchased from Mettler Toledo, Columbus, Ohio. The film sample was first weighed dry in the upper basket, then immersed in water and weighed in the lower basket. The density of the sample is equal to (dry weight * water density) / [dry weight = immersed weight]. The water temperature was checked to ensure an appropriate water density was used. The reported mean and standard deviation are based on three replicates.

[0136] Flammability test method

[0137] Tests were conducted according to UL-94. A test apparatus similar to that described in UL-94 was used for this test. This apparatus consisted of a flame-retardant chamber placed within a fume hood and a gas torch placed within the chamber. A piece of cotton was placed under the flame at the bottom of the combustion chamber. A 0.75 mm thick film sample of the cured composition was prepared by applying the curable composition to a release liner using a benchtop coater and curing it for 24 hours at room temperature in a temperature-controlled (25°C) and humidity-controlled (50% RH) room. A 0.5 inch (1.3 mm) × 5 inch (13 mm) strip was cut from the film for the flame retardancy test. The sample was exposed to a flame from the gas torch according to the test description in UL-94. Samples that self-extinguished after two exposures to the flame and did not ignite the cotton were considered to be of V0 grade. The reported mean and standard deviation are based on results from 10 replicates.

[0138] Viscosity testing methods

[0139] Tests were performed according to DIN 53019. Viscosity was measured using a DHR rheometer with a parallel plate geometry (25 mm diameter), purchased from TA Instruments, Newcastle, Delaware. The composition was conditioned in the rheometer chamber at room temperature (25°C) for 10 minutes prior to measurement. Viscosity was measured at 0.001 s. -1 and 10s -1 Shear scans are performed between shear rates, and the results are reported within 2 seconds. -1 Viscosity at shear rate.

[0140] Hardness testing methods

[0141] Tests were performed according to ASTM D2240. Hardness was measured using a Shore A hardness tester and a Shore 00 hardness tester, both purchased from Mitutoyo (Aurora, IL, US). Tests were conducted at room temperature. The reported mean and standard deviation are based on five replicates.

[0142] Volume resistivity test method

[0143] Tests were performed according to ASTM D257. Volume resistivity was measured using a Keithley 6517A electrometer, purchased from Keithley Instruments, Cleveland, Ohio. A film sample of approximately 0.25 mm thick cured composition was prepared by applying the curable composition to a release liner using a benchtop coater and curing at room temperature in a temperature-controlled (25°C) and humidity-controlled (50% RH) room for 24 hours. For testing, a 5-inch (13 mm) × 5-inch (13 mm) square was cut from the film. Volume resistivity was measured using a Keithley 6517A electrometer with a resolution of 100 amperes and an applied voltage of 500 volts. A Keithley 8009 resistivity test fixture was used with compressible conductive rubber electrodes, applying an electrode force of 1 pound (4.4 N) to the area of ​​the electrodes (2.5-inch (6.4 cm) in diameter) and the sample. The samples were approximately 10 mils (0.25 mm) thick. Each sample was measured once, with a charging time of 60 seconds. High-resistivity PTFE, low-resistivity (high-capacity carbon-loaded polyimide film (kapton)), and medium-resistivity (paper) samples were used as material reference standards.

[0144] Dielectric breakdown test method

[0145] Tests were performed according to ASTM D149. Dielectric breakdown strength was measured using a 6TC4100-10 / 50-2 / D149 automated dielectric test kit from Phoenix Contact, Maryland, Inc. Film samples of approximately 0.25 mm thick cured composition were prepared by applying the curable composition to a release liner using a benchtop coater and curing at room temperature in a controlled temperature (25°C) and humidity (50% RH) room for 24 hours. For testing, 5-inch (13 mm) × 5-inch (13 mm) squares were cut from the film. Tests were performed using a frequency of 60 Hz and a ramp rate of 500 volts per second. The reported mean and standard deviation of breakdown strength are based on results from 10 replicates.

[0146] Mixing process for preparing curable compositions

[0147] To prepare the formulation, all organic components, except the catalyst, were mixed at 2000 rpm for two minutes in a SPEEDMIXER DAC 400VAC (FlackTek, Inc., Landrum, South Carolina) in the amounts shown in the table below. Inorganic fillers were added in small, multiple steps to ensure proper dispersibility, and after each addition of filler, the mixture was mixed at 2000 rpm for 1 minute. The catalyst was then added and mixed at 2000 rpm for 30 seconds. The composition was degassed at 40 Torr for 1 minute using the SPEEDMIXER DAC 400VAC. Approximately 400 g of curable composition was prepared for each sample.

[0148] For the two-part composition, parts A and B were prepared as follows: First, the resin components were mixed, then inorganic fillers and pyrolytic silica were added in small batches multiple times, followed by degassing. Then, before preparing the cured film, parts A and B were mixed in a high-speed mixer at a 1:1 volume ratio at 2000 rpm for 1 minute.

[0149] The films were prepared by coating between conventional release liner sheets at various thicknesses. The films were cured at room temperature for 24–48 hours in a room with constant temperature (25°C) and humidity (50% RH) before testing various thermophysical and dielectric properties.

[0150] Table 1. Single-component curable compositions (values ​​in grams)

[0151] Components Example 1 Comparative Example 2 TM2250 14.95 14.95 BAK10 14.95 14.95 BAK70 44.85 44.85 ATH A110 14.02 14.02 ZHS 2.12 - Ricon MA8 5.14 5.14 Vikoflex 9400 1.1 1.1 Pripol 2033 1.15 1.15 FARMIN D2098 1.0 1.0 R805 0.1 0.1

[0152] Table 2. Characteristics of Example 1 and Comparative Example 2

[0153]

[0154]

[0155] Table 3. Two-part curable compositions (values ​​in grams)

[0156] Components Example 2 Example 3 Example 4 Example 5 Part B Pripol 2033 2.54 2.54 2.52 2.74 FARMIN D2098 0.53 0.53 0.52 2.02 DMDEE 2.11 2.11 2.09 0.71 URIC H-30 0.94 0.94 0.93 1.01 EFKA PL 5635 1.51 1.51 1.49 1.52 BYK 108 1.51 1.51 1.49 1.52 AO (Irganox 1520) 0.09 0.09 0.09 0.06 ZHS 4.71 4.71 4.66 5.07 TM2250 0.00 0.00 0.00 0.00 BAK70 46.15 46.15 45.71 46.69 ATH A110 39.84 39.84 39.46 38.57 R805 0.08 0.00 0.00 0.08 CFP001 0.00 0.08 1.03 0.00 Part A Ricon MA 8 11.39 11.39 11.28 10.69 RBD soybean oil 1.04 1.04 1.03 0.52 EFKA PL 5635 0.85 0.85 0.84 0.87 Irganox 1520 0.09 0.09 0.09 0.04 TM2250 0.00 0.00 0.00 0.00 ATH A110 47.05 47.05 46.60 44.34 BAK70 39.52 39.52 39.14 43.47 R805 0.08 0.00 0.00 0.07 CFP001 0.00 0.08 1.03 0.00

[0157] Table 4. Characteristics of Example 5

[0158]

[0159]

[0160] Table 5. Two-part curable compositions (values ​​in grams)

[0161] Components Example 6 Example 7 Example 8 Part B Pripol 2033 2.95 2.95 2.83 FARMIN D2098 0.55 2.74 2.62 URIC H-30 0.00 1.09 1.05 TEHA (Tri-2-(Ethylhexylamine)) 2.18 0.00 0.00 EFKAPL 5635 1.97 1.64 1.57 BYK 108 1.64 1.64 1.57 ZHS 5.46 0.00 0.00 Irganox 1520 0.00 0.11 0.10 TM2250 10.04 13.13 14.68 BAK 10 10.04 0.00 0.00 BAK70 30.13 18.60 17.82 ATH A110 0.00 57.99 57.65 Apyral 20x 34.93 0.00 0.00 R805 0.11 0.11 0.10 Part A RiconMA 8 10.45 10.83 10.72 RBD soybean oil 0.00 0.00 1.05 TM2250 17.70 0.88 0.87 BAK 10 17.70 0.09 0.09 BAK70 53.10 17.61 17.43 EFKAPL 5635 0.86 39.63 39.22 R805 0.13 30.82 30.50 Irganox 1520 0.07 0.13 0.13

[0162] Table 6: Characteristics of Examples 6-8

[0163]

[0164]

[0165] Various modifications and alterations to this disclosure will become apparent to those skilled in the art without departing from its scope and spirit. It should be understood that this disclosure is not intended to be unduly limited to the exemplary embodiments and examples shown herein, and such embodiments and examples are presented by way of example only. The scope of this disclosure is intended to be limited only by the claims set forth herein. All references cited in this disclosure are incorporated herein by reference in their entirety.

Claims

1. A curable composition, said curable composition comprising, based on its total weight: 0.1-20% by weight of a polyol component, wherein the polyol component comprises one or more polyols; 1-40% by weight of functionalized butadiene components; and At least 20% by weight of filler particles, said filler particles comprising aluminum trihydrate and a smoke suppressant selected from zinc hydroxystannate, zinc stannate, calcium stannate and calcium hydroxystannate, wherein, based on the total weight of the filled curable composition, the smoke suppressant is present in the curable composition in an amount of at least 0.5% by weight and the aluminum trihydrate is present in the curable composition in an amount of at least 10% by weight; The curable composition, after curing, has a thermal conductivity of at least 3.0 W / (mK), and The functionalized butadiene component comprises maleated polybutadiene or is composed of maleated polybutadiene.

2. The curable composition according to claim 1, wherein the smoke suppressant comprises zinc hydroxystannate.

3. The curable composition according to claim 1, wherein the filler particles further comprise alumina.

4. The curable composition according to claim 1, wherein the curable composition has a density of less than 2.5 g / cc after curing.

5. The curable composition according to claim 1, wherein the curable composition has a UL-94 flame retardancy rating of V0 after curing.

6. The curable composition according to claim 1, wherein the polyol component further comprises one or more monofunctional alcohols.

7. The curable composition according to claim 1, wherein the curable composition further comprises a resin capable of reacting with an acid / ester formed when the alcohol group of the polyol reacts with the functionalized butadiene component.

8. The curable composition of claim 7, wherein the resin comprises epoxidized vegetable oil, epoxidized fatty acid ester, epoxidized α-olefin, or epoxidized polybutene.

9. The curable composition according to claim 1, wherein the curable composition further comprises an amine catalyst.

10. An article comprising a first substrate, a second substrate, and a cured composition, the cured composition being disposed between the first substrate and the second substrate and adhering the first substrate to the second substrate, wherein the cured composition is a reaction product of the curable composition according to claim 1.

11. A battery module comprising a plurality of battery cells connected to a first substrate via a first layer of the curable composition according to claim 1.

12. A method for manufacturing a battery module, the method comprising: The first layer of the curable composition according to claim 1 is applied to the first surface of the first substrate; Multiple battery cells are attached to the first layer to connect the battery cells to the first substrate; as well as The curable composition is cured.

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