CURABLE COMPOSITIONS, ARTICLES COMPOSED THEREOF, AND METHODS FOR MAKING AND USING SAME - Patent application

Abstract

The curable composition includes a first part including an epoxy resin and a second part including a multifunctional functional thiol-containing compound. The curable composition further includes an inorganic filler present in an amount of at least 40 wt.%, based on the total weight of the curable composition. The multifunctional functional thiol-containing compound includes an ether in its backbone.

Description

[Background technology]

[0001] Claiming priority This application claims priority to PCT Application No. PCT / CN2019 / 079523, filed March 25, 2019. [Technical field]

[0002] The present disclosure generally relates to curable compositions that include an epoxy composition and a thiol composition. Such curable compositions may be used, for example, as thermally conductive gap fillers, which may be suitable for use in electronic applications such as battery assemblies.

[0003] Curable compositions based on epoxy or polyamide resins have been disclosed in the art, for example in U.S. Pat. No. 9,926,405 and U.S. Patent Application Publication No. 2013 / 0165600, and in European Patent No. 1291390. Summary of the Invention

[0004] In some embodiments, a curable composition is provided. The composition includes a first part including an epoxy resin and a second part including a multifunctional functional thiol-containing compound. The curable composition further includes an inorganic filler present in an amount of at least 40 wt.%, based on the total weight of the curable composition. The multifunctional functional thiol-containing compound includes an ether in its backbone. [Brief description of the drawings]

[0005] [Figure 1] 1 illustrates an exemplary battery module assembly according to some embodiments of the present disclosure. [Diagram 2] 2 shows an assembled battery module corresponding to FIG. 1. [Diagram 3] 1 illustrates an exemplary battery subunit assembly according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Thermal management plays an important role in many electronics applications, such as electric vehicle (EV) battery assemblies, power electronics, electronic packaging, LEDs, solar cells, electrical grids, etc. Certain thermally conductive materials (e.g., adhesives) may be attractive choices for these applications due to their ability to efficiently dissipate heat while having good electrical insulation, feasibility in processing for integrated parts or complex geometric shapes, and good conformability / wetting to different surfaces, especially good adhesion to different substrates for assembly.

[0007] Regarding the application in EV battery assembly, one such application that utilizes thermally conductive materials at present is gap filler application.Generally, the requirements for gap filler application include high thermal conductivity, good overlap shear adhesive strength, good tensile strength, good elongation at break of toughness, good vibration damping performance, and good hydrolysis stability, in addition to having low viscosity before curing.However, in order to achieve high thermal conductivity, typically a large amount of inorganic thermally conductive filler is added to the composition.However, high loading of thermally conductive filler has a detrimental effect on adhesive performance, toughness, vibration damping performance, elongation at break, and viscosity.

[0008] Additionally, compositions useful for gap filler applications should possess relatively fast cure characteristics to accommodate the automated processing requirements of the industry.

[0009] A filled curable composition comprising an epoxy resin, a polyamide composition, an amino-functional compound, and a multifunctional (meth)acrylate provides many of the attributes described above, but does not provide sufficient hydrolytic stability for some applications. Another filled curable composition comprising an epoxy composition and a polyamide composition, the polyamide composition comprising a polyamide having one or more tertiary amides in its backbone, provides many of the attributes described above, but does not provide sufficient elongation at break for some applications.

[0010] To solve the above-mentioned problems associated with high loadings of inorganic thermally conductive fillers, a curable composition has been discovered that provides a good balance of the desired properties described above, including epoxy and thiol compositions. Specifically, in addition to exhibiting all of the desired attributes described above, the curable composition of the present disclosure is capable of achieving high thermal conductivity, high bond strength, while simultaneously achieving high elongation at break.

[0011] As used herein, The term "room temperature" refers to a temperature between 22°C and 25°C.

[0012] The terms "curing" and "curable" refer to the bonding of polymer chains together to form a network polymer, usually by covalent chemical bonds via crosslinking molecules or groups. Thus, in this disclosure, the terms "curing" and "crosslinking" may also be used interchangeably. Cured or crosslinked polymers are generally characterized as insoluble, although they may become swellable in the presence of an appropriate solvent.

[0013] The term "unfilled" when used in connection with a component or composition refers to all materials that make up the component or composition except for inorganic fillers (eg, thermally conductive fillers).

[0014] The term "backbone" refers to the main continuous chain of a polymer.

[0015] The term "aliphatic" refers to a C1-C40, preferably C1-C30, straight or branched chain alkenyl, alkyl, or alkynyl, which may or may not be interrupted or substituted by one or more heteroatoms such as O, N, or S.

[0016] The term "alicyclic" refers to a cyclic aliphatic C3-C30, preferably C3-C20, group interrupted by one or more heteroatoms, such as O, N, or S.

[0017] The term "alkyl" refers to a monovalent group that is a radical of an alkane, including linear, branched, cyclic, and bicyclic alkyl groups and groups that are 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 have 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, t-butyl, isopropyl, n-octyl, n-heptyl, ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornyl, and the like.

[0018] The term "alkylene" refers to a divalent group that is an alkane radical, including groups that are linear, branched, cyclic, bicyclic, 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.

[0019] The term "aromatic" refers to aromatic groups of C3 to C40, preferably C3 to C30, including both carbocyclic aromatic groups and heterocyclic aromatic groups containing one or more heteroatoms, O, N, or S, and fused ring systems in which one or more of these aromatic groups are fused together.

[0020] The term "aryl" refers to a monovalent group that is aromatic and optionally carbocyclic. An aryl 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 carbocyclic rings fused to the aromatic ring. Unless otherwise specified, an aryl group typically has 6 to 30 carbon atoms. In some embodiments, an aryl group has 6 to 20, 6 to 18, 6 to 16, 6 to 12, or 6 to 10 carbon atoms. Examples of aryl groups include phenyl, naphthyl, biphenyl, phenanthryl, and anthracyl.

[0021] The term "arylene" refers to a divalent group that is aromatic and optionally carbocyclic. An arylene has at least one aromatic ring. Optionally, the aromatic ring can have one or more additional carbocyclic rings fused to the aromatic ring. Any additional rings can be unsaturated, partially saturated, or saturated. Unless otherwise specified, arylene groups often 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.

[0022] The term "aralkyl" refers to a monovalent group that is an alkyl group substituted with an aryl group, such as, for example, benzyl. The term "alkaryl" refers to a monovalent group that is an aryl group substituted with an alkyl group, such as, for example, tolyl. Unless otherwise specified, in either group, the alkyl portion often has 1-10 carbon atoms, 1-6 carbon atoms, or 1-4 carbon atoms, and the aryl portion often has 6-20 carbon atoms, 6-18 carbon atoms, 6-16 carbon atoms, 6-12 carbon atoms, or 6-10 carbon atoms.

[0023] Repeated use of reference characters in the specification is intended to represent the same or similar features or elements of the disclosure. As used herein, the symbol "~", when applied to a numerical range, includes the endpoints of the range unless otherwise specified. Recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range.

[0024] It is understood that those skilled in the art can devise many other modifications and embodiments that fall within the scope and spirit of the principles of the present disclosure. All scientific and technical terms used herein have the meanings commonly used in the art unless otherwise specified. The definitions provided herein are intended to aid in the understanding of certain terms used frequently herein and are not intended to limit the scope of the present disclosure. As used herein and in the appended claims, the singular forms "a", "an" and "the" include embodiments having plural referents unless the context clearly dictates otherwise. As used herein and in the appended claims, the term "or" is generally used in the sense of including "and / or" unless the context clearly dictates otherwise.

[0025] In some embodiments, the present disclosure provides highly filled thermally conductive curable compositions formulated by blending an epoxy composition with a thiol composition.

[0026] In some embodiments, the epoxy composition may include one or more epoxy resins. Suitable epoxy resins may include aromatic polyepoxide resins (e.g., chain-extended diepoxides or novolac epoxy resins having at least two epoxide groups), aromatic monomeric diepoxides, aliphatic polyepoxides, or monomeric diepoxides. Crosslinkable epoxy resins will typically have at least two epoxy end groups. Aromatic polyepoxides or aromatic monomeric diepoxides typically contain at least one (in some embodiments, at least two, in some embodiments, ranging from 1 to 4) aromatic rings that are optionally substituted with halogen (e.g., fluoro, chloro, bromo, iodo), alkyl having 1 to 4 carbon atoms (e.g., methyl or ethyl), or hydroxyalkyl having 1 to 4 carbon atoms (e.g., hydroxymethyl). For epoxy resins that contain two or more aromatic rings, the rings may be linked by, for example, branched or linear alkylene groups having 1 to 4 carbon atoms that may be optionally substituted with halogen (e.g., fluoro, chloro, bromo, iodo).

[0027] In some embodiments, examples of aromatic epoxy resins useful in the epoxy compositions disclosed herein can include novolac epoxy resins (e.g., phenol novolac, ortho-, meta-, or para-cresol novolac, or combinations thereof), bisphenol epoxy resins (e.g., bisphenol A, bisphenol F, halogenated bisphenol epoxies, and combinations thereof), resorcinol epoxy resins, tetrakisphenylolethane epoxy resins, and combinations of any of these.

[0028] In some embodiments, useful epoxy compounds include diglycidyl ethers of difunctional phenolic compounds (e.g., p,p'-dihydroxydibenzyl, p,p'-dihydroxydiphenyl, p,p'-dihydroxyphenylsulfone, p,p'-dihydroxybenzophenone, 2,2'-dihydroxy-1,1-dinaphthylmethane, and the isomers of 2,2', 2,3', 2,4', 3,3', 3,4', and 4,4' dihydroxydiphenylmethane, dihydroxydiphenyldimethylmethane, dihydroxydiphenylethylmethylmethane, dihydroxydiphenylmethylpropylmethane, dihydroxydiphenylethylphenylmethane, dihydroxydiphenylpropylphenylmethane, dihydroxydiphenylbutylphenylmethane, dihydroxydiphenyltolylethane, dihydroxydiphenyltolylmethylmethane, dihydroxydiphenyldicyclohexylmethane, and dihydroxydiphenylcyclohexane). In some embodiments, the adhesive includes diglycidyl ethers of bisphenols, such as bisphenols (i.e., -OC 6 H 5 -CH 2 -C 6 H 5 -O-) can be unsubstituted (e.g., bisphenol F) or either the phenyl ring or the methylene groups can be substituted with one or more halogen (e.g., fluoro, chloro, bromo, iodo), methyl, trifluoromethyl, or hydroxymethyl groups.

[0029] In some embodiments, examples of aromatic monomeric diepoxides useful in the epoxy compositions according to the present disclosure include diglycidyl ethers of bisphenol A and bisphenol F, and mixtures thereof. Bisphenol epoxy resins may be chain extended, for example, to have any desired epoxy equivalent weight. Chain extension of epoxy resins can be carried out, for example, by reacting a monomeric diepoxide with a bisphenol in the presence of a catalyst to make a linear polymer. Other aromatic epoxy resins can include difunctional epoxy resins with polysulfide polymer backbones, such as block copolymers of Thiokol LP and bisphenol F epoxy resins (e.g., FLEP-60 available from Toray Fine Chemicals Co., Ltd., Tokyo, Japan).

[0030] In some embodiments, the aromatic epoxy resin (e.g., either a bisphenol epoxy resin or a novolac epoxy resin) may have an epoxy equivalent weight of at least 150, 170, 200, or 225 grams per equivalent. In some embodiments, the aromatic epoxy resin may have an epoxy equivalent weight of up to 2000, 1500, or 1000 grams per equivalent. In some embodiments, the aromatic epoxy resin may have an epoxy equivalent weight in the range of 150 to 2000, 150 to 1000, or 170 to 900 grams per equivalent. In some embodiments, the first epoxy resin has an epoxy equivalent weight in the range of 150 to 450, 150 to 350, or 150 to 300 grams per equivalent. The epoxy equivalent weight may be selected, for example, such that the epoxy resin can be used as a liquid or solid, as desired.

[0031] In some embodiments, in addition to or as an alternative to an aromatic epoxy resin, the epoxy resin of the present disclosure may include one or more non-aromatic epoxy resins. In some cases, non-aromatic epoxy resins may be useful as reactive diluents that may help control the flow properties of the composition. Non-aromatic epoxy resins useful in the curable compositions according to the present disclosure may include branched or linear alkylene groups having 1 to 20 carbon atoms, optionally interrupted by at least one -O-, and optionally substituted with hydroxyl. In some embodiments, the non-aromatic epoxy may include a poly(oxyalkylene) group OR having multiple (x) oxyalkylene groups. 1 wherein each IV independently comprises: 2 ~C 5 alkylene, and in some embodiments, C 2 ~C 3alkylene, where x is 2 to about 6, 2 to 5, 2 to 4, or 2 to 3. To become crosslinked into a network, useful non-aromatic epoxy resins will typically have at least two epoxy end groups. Examples of useful non-aromatic epoxy resins include glycidyl epoxy resins, such as those based on diglycidyl ether compounds containing one or more oxyalkylene units. These include resins made from ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, propanediol diglycidyl ether, butanediol diglycidyl ether, and hexanediol diglycidyl ether. Other useful non-aromatic epoxy resins include the diglycidyl ether of cyclohexanedimethanol, the diglycidyl ether of neopentyl glycol, the triglycidyl ether of trimethylolpropane, and the diglycidyl ether of 1,4-butanediol. It can be appreciated that the crosslinked aromatic epoxies (i.e., epoxy polymers) described herein can be prepared by crosslinking aromatic epoxy resins. Crosslinked aromatic epoxies typically contain repeat units that include at least one (in some embodiments at least two, in some embodiments ranging from one to four) aromatic rings (e.g., phenyl groups) that are optionally substituted with one or more halogens (e.g., fluoro, chloro, bromo, iodo), alkyl groups having 1 to 4 carbon atoms (e.g., methyl or ethyl), or hydroxyalkyl groups having 1 to 4 carbon atoms (e.g., hydroxymethyl). For repeat units that contain two or more aromatic rings, the rings can be linked by, for example, branched or straight chain alkylene groups having 1 to 4 carbon atoms that may be optionally substituted with halogens (e.g., fluoro, chloro, bromo, iodo).

[0032] In some embodiments, the epoxy resin of the present disclosure can be liquid at room temperature. Some curable epoxy resins useful in the epoxy composition according to the present disclosure can be commercially available. For example, some epoxy resins of various classes and epoxy equivalent weights are available from Olin Corporation, Clayton MO; Hexion, Inc., Columbus, Ohio; Huntsman Advanced Materials, The Woodlands, Tex.; CVC Specialty Chemicals Inc., Akron, Ohio (obtained from Emerald Performance Materials); and Nan Ya Plastics Corporation, Taipei City, Taiwan. Examples of commercially available glycidyl ethers include diglycidyl ethers of bisphenol A (e.g., those available from Hexion Inc. Columbus Ohio under the trade designations "EPON 828," "EPON 1001," "EPON 1310," and "EPON 1510," those available from Olin Corporation under the trade designation "DER" (e.g., DER 331, 332, and 334), those available from Dainippon Ink and Chemicals, Inc. under the trade designation "EPICLON" (e.g., EPICLON 840 and 850), and those available from Japan Epoxy Resins Co., Ltd. under the trade designation "YL-980"); diglycidyl ethers of bisphenol F (e.g., those available from Dainippon Ink and Chemicals, Inc. under the trade designation "EPICLON" (e.g., EPICLON 830)); polyglycidyl ethers of novolac resins (e.g., Olin Corporation under the trade designation "YL-980"); novolac epoxy resins such as those available under the trade name "DEN" from Olin Corporation (e.g., DEN 425, 431, and 438); and flame retardant epoxy resins (e.g., "DER 560", a brominated bisphenol type epoxy resin available from Olin Corporation).An example of a commercially available non-aromatic epoxy resin is the glycidyl ether of cyclohexanedimethanol available from Hexion Inc. under the trade designation "HELOXY MODIFIER 107."

[0033] In some embodiments, the aromatic epoxy resins useful in the epoxy compositions disclosed herein have the following structural formula: [ka] wherein Ar is an aromatic group having 10 to 20 carbon atoms and 0 to 5 substituents selected from an aliphatic hydrocarbon group, an ether group, or a combination thereof (which may include bisphenol A, bisphenol F, or bisphenol Z).

[0034] Examples of suitable aromatic epoxy resins include those available under the trade designation ARALDITE PY-4122 from Huntsman (Woodlands, TX), SE-4125P from SHIN-A T&C, and Epon 872 from Hexion (Columbus, OH).

[0035] In some embodiments, the epoxy compositions of the present disclosure may comprise an epoxy resin in an amount between 5% and 30%, between 5% and 20%, between 7% and 14% by weight (or even higher, up to 40%, 44%, 50%, or 55%, for curable compositions that do not include a filler), based on the total weight of the curable composition.

[0036] In some embodiments, the thiol composition may include one or more multifunctional functional thiol-containing compounds. As used herein, a thiol is an organosulfur compound containing a carbon-bonded sulfhydryl or mercapto (-C-SH) group. In some embodiments, the multifunctional functional thiol-containing compound may include at least two functional thiols. In some embodiments, one or more of the functional thiols in the multifunctional functional thiol-containing compound may be a terminal thiol. In some embodiments, the multifunctional functional thiol-containing compound may include an ether in its backbone. In some embodiments, in addition to the functional thiol, the multifunctional functional thiol-containing compound may include, for example, one or more alcohol or amine functional groups. In some embodiments, the multifunctional functional thiol may be a difunctional thiol, a trifunctional thiol, a tetrafunctional thiol, or a multifunctional thiol.

[0037] In some embodiments, the polyfunctional functional thiol-containing compound has 2-10 thiol functional groups and is as follows: a) HSR 1 O(CH 2 CHR 2 O) n R 1 SH [In the formula, Each R 1 each independently represents an alkylene group having 2 to 12 carbon atoms; Each R 2 are independently H or CH 3 represents n represents an integer from 1 to 20; b) an epoxy resin, comprising an aliphatic epoxy containing an aliphatic chain having 1 to 18 carbon atoms, a bisphenol epoxy, which may comprise bisphenol A epoxy, bisphenol F epoxy, bisphenol S epoxy, halogenated bisphenol epoxy, or a combination thereof; c) an optional crosslinker, the crosslinker comprising a polyfunctional thiol or a polyfunctional amine; and

[0038] In some embodiments, suitable crosslinkers for multifunctional functional thiol-containing compounds have these structural formulas: [ka] [In the formula, R 13 and R 14 are independently an aliphatic chain, and X is 2 to 10. In some embodiments, the polyfunctional thiol compound can be polyether thiol GPM800 available from Gabriel Chemical, Akron, OH; trimethylol-propane-tri(3-mercapto-propionate) available from Bruno Bock, Marschacht, Germany; pentaerythritol-tetra(3-mercaptopropionate) available from Bruno Bock, Marschacht, Germany; di-pentaerythritol hexakis(3-mercaptopropionate) available from Bruno Bock, Marschacht, Germany; tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate available from Bruno Bock, Marschacht, Germany; trimethylol-propane-tri(2-mercapto-propionate) available from Showa Denko, Japan; Tris[2-(2-mercaptopropionyloxy)ethyl]isocyanurate available from Denko (Japan).

[0039] In some embodiments, suitable multifunctional amine compounds have these structural formulas: [ka] [In the formula, R 15is selected from an aryl group or an aliphatic group. Suitable aryl groups typically have 6 to 12 carbon atoms, such as a phenyl or biphenyl group. Suitable aliphatic groups typically have 1 to 30 carbon atoms, with straight or branched chain alkenyl, alkyl, or alkynyl, which may or may not be interrupted or substituted by one or more heteroatoms, such as O, N, or S.

[0040] In some embodiments, the polyfunctional amine compound includes m-xylylenediamine available from Mitsubishi Gas Chemical (Japan), 1,3-bis(aminoethyl)cyclohexane available from Mitsubishi Gas Chemical (Japan), isophoronediamine available from Evonik (Essen, Germany), trimethylhexamethylenediamine available from Evonik (Essen, Germany), 4,4'-diaminodicyclohexylmethane available from Evonik (Essen, Germany), triethylenetetramine available from TCI (Shanghai, China), tetraethylenepentamine available from TCI (Shanghai, China), 1,8-diamino-3,6-dioxaoctane available from Hunstman (The Woodlands, TX, US), polyetheramine D230 available from Hunstman (The Woodlands, TX, US), or EC130 available from BASF (Shanghai, China).

[0041] In some embodiments, the crosslinker can be present in the multifunctional functional thiol-containing compound in an amount of 0% to 30% by weight, based on the total weight of the multifunctional functional thiol-containing compound.

[0042] In some embodiments, the multifunctional functional thiol-containing compound has the following formula: [ka] [Wherein, independently, R 3 is R 1 O(CH 2 CHR 2 O) n R 1 and R 4 is a branched aliphatic chain containing 2 to 18 sulfur or nitrogen bonds, a is 2 to 10, or R 4 is HSR 1 O(CH 2 CHR 2 O) n R 1 S, a is 1, R 5 is bisphenol A, or bisphenol F, or bisphenol S, or biphenyl, or a halogenated bisphenol, or an aliphatic chain having 1 to 18 carbon atoms; and m is 0 to 18.

[0043] In some embodiments, the polyfunctional functional thiol-containing compounds according to the present disclosure may include a branched aliphatic chain containing 2-10 sulfur or nitrogen bonds, where n is 2-10. In general, the bonds may act to increase the strength of the curable composition. Suitable sources of branched aliphatic chains according to the present disclosure may include polyfunctional thioether bonds, polyfunctional amine bonds, or combinations thereof.

[0044] An example of a suitable commercially available polyfunctional thiol-containing compound includes that available from Cardolite (Zhuhai, China) under the trade name Cardolite NT-1888.

[0045] In some embodiments, the multifunctional functional thiol-containing compound may be used alone or as a mixture of two or more different thiol-functionalized compounds. In some embodiments, the multifunctional functional thiol-containing compound of the thiol composition may be a liquid (e.g., a viscous liquid having a viscosity of about 500 to 50,000 cP) at room temperature.

[0046] In some embodiments, the epoxy and thiol compositions may be present in the curable composition based on the stoichiometric ratio of the functional groups of each component. Using such relative amounts may be advantageous in that it may reduce the amount of residual unreacted thiol or epoxy in the cured composition, which residual components may migrate or lead to environmental or health problems.

[0047] In some embodiments, the curable compositions of the present disclosure may be provided (e.g., packaged) as a two-part composition, where a first part includes an epoxy composition (hereinafter, "first part") and a second part includes a thiol composition (hereinafter, "second part"). In some embodiments, the first part may include an amount of epoxy resin of at least 10 wt%, at least 14 wt%, at least 28 wt%, at least 40 wt%, or 10-60 wt%, 14-50 wt%, or 28-40 wt%, based on the total weight of the filled first part. In some embodiments, the second part may include an amount of multifunctional functional thiol-containing compound of at least 10 wt%, at least 14 wt%, at least 28 wt%, at least 40 wt%, or 10-60 wt%, 14-50 wt%, or 28-40 wt%, based on the total weight of the filled second part. In some embodiments, the curable composition may include an epoxy resin in an amount of at least 10 wt%, at least 20 wt%, at least 30 wt%, at least 40 wt%, or 10-60 wt%, 14-50 wt%, or 28-40 wt%, based on the total weight of the filled curable composition. In some embodiments, the curable composition may include a multifunctional functional thiol-containing compound in an amount of at least 10 wt%, at least 20 wt%, at least 30 wt%, at least 40 wt%, or 10-60 wt%, 14-50 wt%, or 28-40 wt%, based on the total weight of the filled curable composition.

[0048] In addition to the above materials, the first and second portions may independently include one or more additives, such as inorganic fillers, coupling agents, tougheners, dispersants, catalysts, antioxidants, optional crosslinking agents, etc., which are described in more detail below. The present disclosure further provides a dispenser comprising a first chamber and a second chamber. The first chamber includes a first portion and the second chamber includes a second portion.

[0049] In some embodiments, the curable composition may include one or more inorganic fillers (e.g., thermally conductive inorganic fillers). The inorganic filler may be provided to the curable composition via the first part, the second part, both parts, or after mixing of the first and second parts. In general, the selection and loading level of the inorganic filler may be used to control the thermal conductivity of the curable composition. In some embodiments, the inorganic filler loading may be at least 40 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, or at least 90 wt%, based on the total weight of the curable composition. In some embodiments, the inorganic filler loading may be 40-90 wt%, 40-80 wt%, 50-70 wt%, or 60-65 wt%, based on the total weight of the curable composition. The loading level of the inorganic filler may be expressed both by volume percent (based on the total volume of any or all of the epoxy composition, thiol composition, or curable composition) and by weight percent (based on the total weight of any or all of the epoxy composition, thiol composition, or curable composition). Conversion between volume percent and weight percent of filler is performed using the following formula:

number

[0050] Generally, any known thermally conductive filler can be used, but when breakthrough voltage is a concern, electrically insulating fillers may be preferred. Suitable electrically insulating thermally conductive fillers include ceramics such as oxides, hydroxides, oxyhydroxides, silicates, borides, carbides, and nitrides. Suitable ceramic fillers include, for example, silicon oxide, aluminum oxide, aluminum trihydroxide (ATH), boron nitride, silicon carbide, and beryllium oxide. In some embodiments, the thermally conductive filler comprises ATH. Although ATH is not commonly used in polyurethane-based compositions commonly used for thermal management materials due to its reactivity with isocyanate species and the resulting formulation difficulties, it should be understood that the curable composition of the present disclosure can incorporate such inorganic fillers without drawbacks. Other thermally conductive fillers include carbon-based materials such as graphite, and metals such as aluminum and copper.

[0051] Thermally conductive filler particles are available in a number of shapes, for example, spherical, irregular, plate-like, and needle-like. Through-plane thermal conductivity may be important in certain applications. Thus, in some embodiments, generally symmetrical (e.g., spherical or hemispherical) fillers may be used. To facilitate dispersion and increase filler loading, in some embodiments, the thermally conductive fillers may be surface treated or coated. In general, any known surface treatment and coating may be suitable, including those based on silanes, titanates, zirconates, aluminates, and organic acid chemistries. For powder handling purposes, many fillers are available as polycrystalline agglomerates or aggregates with or without binders. To promote high thermal conductivity formulations, some embodiments may include a mixture of particles and aggregates in various sizes and mixtures.

[0052] In some embodiments, the curable composition of the present disclosure may include one or more silane coupling agents. It has been discovered that the silane coupling agent significantly improves the overlap shear strength of the cured curable composition after aging. In some embodiments, the silane coupling agent may be provided to the curable composition via the first part, the second part, both parts, or after mixing of the first and second parts. Suitable silane coupling agents may include silane thiols, silane amines (e.g., silane secondary amines), or silane epoxies.

[0053] In some embodiments, suitable silane coupling agents may include those described in EPPlueddemann, Silane Coupling Agents, 2nd ed., Springer US, New York, 1991, which is incorporated herein by reference in its entirety. In some embodiments, suitable silane coupling agents may be described as organosilicon compounds having two functional groups with different reactivities, one of which reacts with inorganic materials and the other generally reacts with organic materials. In some embodiments, the silane coupling agent has the following general structural formula: [ka] [wherein Y is a functional group that is compatible with or bonds to organic materials, such as vinyl, epoxy, amino, thiol, isocyanate groups, etc.; R is an aliphatic group (typically an aliphatic group having 2 to 6 carbon atoms); X is a functional group that undergoes hydrolysis with water or moisture to form a silanol (e.g., a chlorine, alkoxy, or acetoxy group); and n is 1 to 3 or 1 to 2.

[0054] Examples of suitable silane coupling agents include 3-glycidoxypropyltriethoxysilane, 5,6-epoxyhexyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, gamma-mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, s-(octanoyl)mercaptopropyltriethoxysilane, hydroxy(polyethyleneoxy)propyltriethoxysilane, N-(n-butyl)-3-aminopropyltrimethoxysilane, or combinations thereof.

[0055] In some embodiments, the first portion may include a silane epoxy and the second portion may include either or both of a silane thiol and a silane amine.

[0056] In some embodiments, the silane coupling agent may be present in the curable composition in an amount of at least 0.1 wt%, at least 10 wt%, or at least 15 wt%, or 0.1-60 wt%, 9-20 wt%, or 14-17 wt%, based on the total weight of the unfilled curable composition. In some embodiments, the silane coupling agent may be present in the first portion in an amount of at least 0.1 wt%, at least 15 wt%, or at least 20 wt%, or 50-90 wt%, 60-80 wt%, or 65-70 wt%, based on the total weight of the unfilled first portion. In some embodiments, the silane coupling agent may be present in the second portion in an amount of at least 0.1 wt%, at least 5 wt%, or at least 10 wt%, or 0.1-40 wt%, 5-16 wt%, or 9-11 wt%, based on the total weight of the unfilled second portion.

[0057] In some embodiments, the curable composition according to the present disclosure may include one or more catalysts. In general, the catalyst may act to promote the curing of the curable composition. Suitable catalysts according to the present disclosure may include a base catalyst, a Lewis acid catalyst, or a combination thereof.

[0058] In some embodiments, a suitable basic catalyst may include a nitrogen-containing catalyst. In some embodiments, the nitrogen-containing catalyst may include an amine-containing catalyst. In some embodiments, the amine-containing catalyst includes a tertiary amine and a primary amine in the backbone. In some embodiments, the amine-containing catalyst is represented by the formula -NR 21 R 22 [In the formula, R 21 and R 22 are independently selected from hydrogen, alkyl, aryl, alkaryl, or aralkyl. Suitable alkyl groups often have 1 to 12 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. The alkyl groups can be cyclic, branched, linear, or combinations thereof. Suitable aryl groups typically have 6 to 12 carbon atoms, such as phenyl or biphenyl groups. Suitable alkylaryl groups can include the same aryl and alkyl groups as described above. In some embodiments, the amine-containing catalyst can be an imidazole, an imidazole salt, an imidazoline, or combinations thereof. Aromatic tertiary amines have the structural formula: [ka] [In the formula, R 24 is hydrogen or an alkyl group, R 25 , R 26 , and R 27 are independently hydrogen or CHNR 28 R 29 and R 25 , R 26 , and R 27 At least one of the CHNR 28 R 29 and R 28 and R 29 In some embodiments, R 25 , R 28 , and / or R 29The alkyl group in the formula is a methyl group or an ethyl group. In some embodiments, the amine-containing catalyst can include tris-2,4,6-(dimethylaminomethyl)phenol, as shown in the following structural formula, commercially available from Evonik Corporation (Parsippany, NJ) under the trade name ANCAMINE K54. [ka]

[0059] In some embodiments, the nitrogen-containing catalyst may include cyclic or bridged nitrogen-containing compounds including amidine compounds such as 1,5-diaza-bicyclo[4.3.0]non-5-ene (DBN) and 1,8-diaza-bicyclo[5.4.0]undec-7-ene (DBU), and also diazabicyclo[2.2.2]octane (DABCO) from Sigma Aldrich (Saint Louis, MO, US), having the following structural formula: [ka]

[0060] In some embodiments, the nitrogen-containing catalyst has the following structural formula: [ka] [In the formula, R 10 and R 11 R may contain reactive functional groups such as primary or secondary amine groups, including those having: R is independently selected from hydrogen, alkyl, aryl, alkaryl, or aralkyl. Suitable alkyl groups often have 1 to 12 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. 12 is an aryl or aliphatic chain having 1 to 18 carbon atoms; suitable aryl groups typically have 6 to 12 carbon atoms, such as phenyl or biphenyl groups. Suitable alkylaryl groups include the same aryl and alkyl groups as described above.

[0061] In some embodiments, the amine-containing catalyst can include 3-(dimethylamino)-1-propylamine, as shown in the following structural formula, commercially available from TCI Corporation (Shanghai, China): [ka]

[0062] In some embodiments, the catalyst may be present in the curable composition (or either the first part and the second part, or both) in an amount of 100 to 10,000 ppm, or 200 to 5,000 ppm, based on the total weight or volume of either or all of the unfilled curable composition, the unfilled first part, or the unfilled second part. It has been discovered that the use of a cyclic-type nitrogen-containing catalyst (such as DABCO) can significantly reduce the cure time of the curable composition of the present disclosure (e.g., by up to 6-fold) relative to the cure time using a non-cyclic nitrogen-containing catalyst (such as K54).

[0063] In some embodiments, the basic catalyst may be present in the curable composition in an amount of at least 1 wt%, at least 2 wt%, or at least 3 wt%, or 1-20 wt%, 2-10 wt%, or 3-5 wt%, based on the total weight of the unfilled curable composition. In some embodiments, the second portion may include a basic catalyst. In some embodiments, the basic catalyst may be present in the second portion in an amount of at least 0.5 wt%, at least 5 wt%, or at least 7 wt%, or 0.5-30 wt%, 5-15 wt%, or 7-10 wt%, based on the total weight of the unfilled second portion. In some embodiments, the second portion may include a Lewis acid catalyst. In some embodiments, the Lewis acid catalyst may be present in the curable composition in an amount of at least 1 wt%, at least 2 wt%, or at least 3 wt%, or 1-20 wt%, 2-10 wt%, or 3-5 wt%, based on the total weight of the unfilled curable composition. In some embodiments, the Lewis acid catalyst may be present in the second portion in an amount of at least 0.5 weight percent, at least 5 weight percent, or at least 7 weight percent, or from 0.5 to 30 weight percent, from 5 to 15 weight percent, or from 7 to 10 weight percent, based on the total weight of the unloaded second portion.

[0064] In some embodiments, the curable composition according to the present disclosure may include one or more dispersants. In general, dispersants may act to stabilize inorganic filler particles in compositions without dispersants, and the particles may aggregate, thus potentially adversely affecting the benefits of the particles in the composition. Suitable dispersants may depend on the particular identity and surface chemistry of the filler. In some embodiments, suitable dispersants according to the present disclosure may include at least a binding group and a compatibilizing segment. The binding group may be ionically bonded to the particle surface. Examples of binding groups for alumina particles include phosphates, phosphonates, sulfonic acids, carboxylic acids, and amines. The compatibilizing segment may be selected to be miscible with the curable matrix. For epoxy resin matrices, useful compatibilizers may include polyalkylene oxides, such as polypropylene oxide, polyethylene oxide, and polycaprolactone, and combinations thereof. Commercially available examples include BYK W-9010 (BYK Additives and Instruments), BYK W-9012 (BYK Additives and Instruments), Disberbyk 180 (BYK Additives and Instruments), and Solplus D510 (Lubrizol Corporation). In some embodiments, the dispersant may be present in the curable composition in an amount of 0.1 to 10 wt%, 0.1 to 5 wt%, 0.5 to 3 wt%, or 0.5 to 2 wt%, based on the total weight of the filled curable composition.

[0065] In some embodiments, the dispersant may be premixed with the inorganic filler prior to incorporation into any or all of the first part, second part, or curable composition. Such premixing may facilitate a filled system that is Newtonian-like or allows for shear thinning behavior.

[0066] In some embodiments, the curable composition according to the present disclosure may include one or more crosslinking agents. In some embodiments, a suitable crosslinking agent of the curable composition may include a multifunctional amine compound.

[0067] In some embodiments, suitable multifunctional amine compounds have these structural formulas: [In the formula, R 15 is selected from an aryl group or an aliphatic group. Suitable aryl groups typically have 6 to 12 carbon atoms, such as a phenyl or biphenyl group. Suitable aliphatic groups typically have 1 to 30 carbon atoms, with straight or branched chain alkenyl, alkyl, or alkynyl, which may or may not be interrupted or substituted by one or more heteroatoms, such as O, N, or S.

[0068] In some embodiments, the polyfunctional amine compound includes m-xylylenediamine available from Mitsubishi Gas Chemical (Japan), 1,3-bis(aminoethyl)cyclohexane available from Mitsubishi Gas Chemical (Japan), isophoronediamine available from Evonik (Essen, Germany), trimethylhexamethylenediamine available from Evonik (Essen, Germany), 4,4'-diaminodicyclohexylmethane available from Evonik (Essen, Germany), triethylenetetramine available from TCI (Shanghai, China), tetraethylenepentamine available from TCI (Shanghai, China), 1,8-diamino-3,6-dioxaoctane available from Hunstman (The Woodlands, TX, US), polyetheramine D230 available from Hunstman (The Woodlands, TX, US), or EC130 available from BASF (Shanghai, China).

[0069] In some embodiments, the crosslinker may be present in the hardenable composition in an amount of from 0% to 18% by weight, or from 0% to 15% by weight, or from 0% to 10% by weight, or from 0% to 5% by weight, based on the total weight of the filled hardenable composition.

[0070] In addition to the additives mentioned above, one or both of the first and second parts may contain further additives, such as any or all of antioxidants / stabilizers, colorants, abrasive granules, thermal decomposition stabilizers, light stabilizers, conductive particles, core-shell tougheners, tackifiers, flow agents, thickeners, matting agents, inert fillers, binders, foaming agents, fungicides, bactericides, surfactants, plasticizers, flame retardants, and other additives known to those skilled in the art. These additives, when present, are added in amounts effective for their intended purpose.

[0071] In some embodiments, upon curing, the curable compositions of the present disclosure may exhibit thermal, mechanical, and rheological properties that make them particularly useful as thermally conductive gap fillers. For example, the curable compositions of the present disclosure are believed to provide an optimal blend of tensile strength, elongation at break, and overlap shear strength (even after aging) for certain EV battery assembly applications.

[0072] In some embodiments, the cured composition may have an elongation at break in the range of 0.1-300%, 0.1-100%, 0.5-80%, 1-50%, or 8-15% at a tensile speed of 0.8-1.5 mm / min for a fully cured system (for purposes of this application, elongation at break values ​​are those measured according to ASTM D638-14, "Standard Test Method for Tensile Properties of Plastics"), or in the range of at least 1%, at least 3%, at least 7%, at least 10%, or at least 15% at a tensile speed of 0.8-1.5 mm / min for a fully cured system.

[0073] In some embodiments, the curing composition has a viscosity of 1 N / mm for a fully cured system. 2 ~30N / mm 2 , 1N / mm 2 ~25N / mm 2 , 3N / mm 2 ~20N / mm 2 , 4N / mm 2~20N / mm 2 , 6N / mm 2 ~20N / mm 2 , 2N / mm 2 ~16N / mm 2 , or 3N / mm 2 ~8N / mm 2 (For purposes of this application, lap shear strength values ​​are those measured on untreated aluminum substrates (i.e., aluminum substrates having no surface treatments or coatings other than a native oxide layer) in accordance with the procedure of ASTM D1002-01, "Standard Test Method for Apparent Shear Strength of Single-Lap-Joint Adhesively Bonded Metal Specimens by Tension Loading (Metal-to-Metal)."

[0074] In some embodiments, the curable composition, upon curing, has (i) an elongation at break of 9% or more, and (ii) a hardness of 3 to 20 N / mm on untreated aluminum. 2 It has an overlap shear strength of

[0075] In some embodiments, the cured composition has a resistance of 0.5 N / mm2 at a pull rate of 0.8 to 1.5 mm / min for a fully cured system. 2 ~16N / mm 2 , 1N / mm 2 ~10N / mm 2 , or 2N / mm 2 ~8N / mm 2 (For purposes of this application, tensile strength values ​​are those measured in accordance with ASTM D638-14, "Standard Test Method for Tensile Properties of Plastics").

[0076] In some embodiments, upon curing, the curable compositions of the present disclosure have a viscosity of 1.0 W / (m * K)~5W / (m * K), 1.0W / (m* K)~2W / (m * K), or 1.5W / (m * K)~1.8W / (m * (For purposes of this application, thermal conductivity values ​​are 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 diffusivity, heat capacity, and density measurements according to the formula:

number

[0077] In some embodiments, within 10 minutes of mixing the first and second parts, the viscosity of the curable / partially cured composition measured at room temperature may range from 100 to 50,000 poise and at 60° C. may range from 100 to 50,000 poise. Further, with respect to viscosity, the viscosity of the epoxy composition measured at room temperature (before mixing) may range from 100 to 100,000 poise and at 60° C. may range from 10 to 10,000 poise, and the viscosity of the thiol composition measured at room temperature (before mixing) may range from 100 to 100,000 poise and at 60° C. may range from 10 to 10,000 poise (for purposes of this application, viscosity values ​​are measured using a 25 mm parallel plate geometry at 1% strain on an ARES rheometer (TA Instruments, New Castle, DE, USA) with a forced convection oven attachment at an angular frequency in the range of 10 to 500 rad / sec).

[0078] The present disclosure further relates to a method for producing the curable composition. In some embodiments, the curable composition of the present disclosure can be prepared by first mixing the components of the first part (including any additives) and separately mixing the components of the second part (including any additives). The components of both the first part and the second part can be mixed using any conventional mixing technique, including the use of a speed mixer. In embodiments in which a dispersant is used, the dispersant can be premixed with the inorganic filler before being incorporated into the composition. The first part and the second part can then be mixed together using any conventional mixing technique to form the curable composition.

[0079] In some embodiments, the curable composition of the present disclosure can be cured without the use of a catalyst or other curing agent. In general, the curable composition can be cured at room temperature without the need for typical application conditions, such as high temperature or actinic radiation (e.g., ultraviolet light). In some embodiments, the first curable composition cures at room temperature or below.

[0080] In some embodiments, the curable composition of the present disclosure may be provided as a two-component composition. Generally, the two components of the two-component composition may be mixed before being applied to the substrate to be bonded. After mixing, the two-component composition can reach a desired handling strength and ultimately achieve a desired final strength. Applying the curable composition can be performed, for example, by dispensing the curable composition from a dispenser that includes a first chamber, a second chamber, and a mixing tip, where the first chamber includes a first portion and the second chamber includes a second portion, and the first chamber and the second chamber are connected to the mixing tip to allow the first portion and the second portion to flow through the mixing tip.

[0081] The curable compositions of the present disclosure may be useful in coatings, molded articles, adhesives (including structural and semi-structural adhesives), magnetic media, filled or reinforced composites, caulking and sealing compounds, casting and molding compounds, potting and encapsulating compounds, impregnation and coating compounds, conductive adhesives for electronic devices, protective coatings for electronic devices, primers or adhesion promoting layers, and other applications known to those of skill in the art. In some embodiments, the present disclosure provides articles comprising a substrate having a cured coating of the curable composition.

[0082] In some embodiments, the curable composition may function as a structural adhesive, i.e., the curable composition can bond a first substrate to a second substrate after curing. Generally, the bond strength (e.g., peel strength, overlap shear strength, or impact strength) of a structural adhesive continues to build up sufficiently after an initial curing time. In some embodiments, the present 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 the curable composition according to any one of the curable compositions of the present disclosure. In some embodiments, the first and / or second substrate may be at least one of a metal, a ceramic, and a polymer, such as a thermoplastic resin.

[0083] The curable composition may be coated on a substrate at a useful thickness ranging from 5 microns to 10,000 microns, 25 microns to 10,000 microns, 100 microns to 5,000 microns, or 250 microns to 1,000 microns. Useful substrates may be of any nature and composition and may be inorganic or organic. Representative examples of useful substrates include ceramics, siliceous substrates including glass, metals (e.g., aluminum or steel), natural and man-made stone, woven and non-woven articles, polymeric materials including thermoplastic and thermoset, (e.g., polymethyl (meth)acrylate, polycarbonate, polystyrene, styrene acrylonitrile copolymers, polyesters, styrene copolymers such as polyethylene terephthalate), silicones, 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 aforementioned materials.

[0084] In another aspect, the present disclosure provides a coated article comprising a metal substrate comprising a coating of an uncured, partially cured, or fully cured curable composition on at least one surface thereof. If the substrate has two major surfaces, the coating can be coated on one or both major surfaces of the metal substrate and can include additional layers such as bonding layers, tie layers, protective layers, and topcoat layers. The metal substrate can be, for example, at least one of the interior and exterior surfaces of a pipe, container, conduit, rod, contoured article, sheet, or tube.

[0085] In some embodiments, the present disclosure is further directed to a battery module comprising the uncured, partially cured, or fully cured curable composition of the present disclosure. Components of a representative battery module during assembly are shown in FIG. 1, and an assembled battery module is shown in FIG. 2. A battery module 50 can be formed by placing a plurality of battery cells 10 on a first base plate 20. Generally, any known battery cell may be used, including, for example, hard case prismatic cells or pouch type cells. The number, size, and location of cells associated with a particular battery module may be tailored to meet specific design and performance requirements. The structure and design of base plates are well known, and any base plate suitable for the intended application (typically a metal base plate made from aluminum or steel) can be used.

[0086] The battery cells 10 can be connected to the first base plate 20 via a first layer 30 of a first curable composition according to any of the embodiments of the present disclosure. The first layer 30 of the curable composition can provide a first level of thermal management where the battery cells are assembled into a battery module. Breakthrough voltage can be an important safety feature of this layer, since a voltage difference (e.g., up to 2.3 volts) can occur between the battery cells and the first base plate. Thus, in some embodiments, electrically insulating fillers such as ceramics (typically alumina and boron nitride) can be preferred for use in the curable composition.

[0087] In some embodiments, the layer 30 may include a discrete pattern of the first curable composition applied to the first surface 22 of the first base plate 20, as shown in FIG. 1. For example, a pattern of material for a desired layout of battery cells may be applied to the surface of the base plate (e.g., applied by a robot). In some embodiments, the first layer may be formed as a coating of the first curable composition that covers all or substantially all of the first surface of the first base plate. In an alternative embodiment, the first layer may be formed by applying the curable composition directly to the battery cells and then attaching them to the first surface of the first base plate.

[0088] In some embodiments, the curable composition may need to accommodate dimensional variations of up to 2 mm, up to 4 mm, or even more. Thus, 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. To increase the breakthrough voltage, depending on the electrical properties of the material, a thicker layer (for example, in some embodiments, at least 1, at least 2, or even at least 3 mm thick) may be required. In general, to maximize heat conduction through the curable composition and minimize costs, the curable composition layer should be as thin as possible while still ensuring good contact with the heat sink. Thus, in some embodiments, the first layer is 5 mm thick or less, for example, 4 mm thick or less, or even 2 mm thick or less.

[0089] As the first curable composition cures, the battery cells are held more firmly in place. Once curing is complete, the battery cells are finally secured in the desired position as shown in Figure 2. Additional elements such as bands 40 may be used to secure the cells for shipping and further handling.

[0090] Generally, it is desirable for the curable composition to cure under typical application conditions, such as without the need for elevated temperatures or actinic radiation (e.g., ultraviolet light). In some embodiments, the first curable composition cures at room temperature or at or below 30° C., such as at or below 25° C., or even at or below 20° C.

[0091] In some embodiments, the time to cure is 60 minutes or less, such as 40 minutes or less, or even 20 minutes or less. Although very rapid cure (e.g., less than 5 minutes, or even less than 1 minute) may be suitable for some applications, in some embodiments, an open time of at least 5 minutes, such as at least 10 minutes, or even at least 15 minutes, may be desired to allow time for placement and repositioning of the battery cells. Generally, it is desirable to achieve the desired cure time without the use of expensive catalysts such as platinum.

[0092] As shown in Figure 3, a plurality of battery modules 50, such as those shown and described in connection with Figures 1 and 2, are assembled to form a battery subunit 100. The number, size, and location of modules associated with a particular battery subunit may be tailored to meet particular design and performance requirements. The structure and design of second base plates are well known, and any base plate suitable for the intended application (typically a metal base plate) may be used.

[0093] Individual battery modules 50 may be disposed on and connected to the second base plate 120 via a second layer 130 of a curable composition according to any of the embodiments of the present disclosure.

[0094] A second layer 130 of the second curable composition may be disposed between the second surface 24 of the first base plate 20 (see FIGS. 1 and 2) and the first surface 122 of the second base plate 120. The second curable composition may provide a second level of thermal management where the battery modules are assembled into battery subunits. At this level, breakthrough voltage may not be a requirement. Thus, 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.

[0095] In some embodiments, the second layer 130 may be formed as a coating of the second curable composition covering all or substantially all of the first surface 122 of the second base plate 120, as shown in FIG. 3. In some embodiments, the second layer may include a discrete pattern of the second curable composition applied to the surface of the second base plate. For example, a pattern of material corresponding to the desired layout of the battery modules may be applied (e.g., applied by a robot) to the surface of the second base plate. In an alternative embodiment, the second layer may be formed by applying the second curable composition directly to the second surface 24 of the first base plate 20 (see FIGS. 1 and 2) and then attaching the modules to the first surface 122 of the second base plate 120.

[0096] Assembled battery subunits may be combined to form further structures. For example, as is known, battery modules may be combined with other elements, such as a battery control unit, to form a battery system, such as a battery system for use in an electric vehicle. In some embodiments, additional layers of a curable composition according to the present disclosure may be used in the assembly of such a battery system. For example, in some embodiments, a thermally conductive gap filler according to the present disclosure may be used to mount and aid in cooling the battery control unit.

[0097] LIST OF EMBODIMENTS 1. A curable composition comprising: a first portion comprising an epoxy resin; a second portion comprising a multifunctional functional thiol-containing compound; an inorganic filler present in an amount of at least 40 wt.%, based on the total weight of the curable composition; The functional thiol-containing compound may have 2 to 10 thiol functional groups and is selected from the group consisting of: a) HSR 1 O(CH 2 CHR 2 O) n R 1 SH [In the formula, Each R 1 each independently represents an alkylene group having 2 to 12 carbon atoms; Each R 2 are independently H or CH 3 represents n represents an integer from 1 to 20; b) an epoxy resin, the epoxy resin including an aliphatic epoxy containing an aliphatic chain having 1 to 18 carbon atoms, a bisphenol epoxy, the bisphenol epoxy may include bisphenol A epoxy, bisphenol F epoxy, bisphenol S epoxy, halogenated bisphenol epoxy, or a combination thereof; c) an optional crosslinker, the crosslinker comprising a multifunctional thiol or a multifunctional amine; and

[0098] 2. The polyfunctional thiol-containing compound has the following formula: [ka] [Wherein, independently, R 3 is R 1 O(CH 2 CHR 2 O) n R 1 and R 4is a branched aliphatic chain containing 2 to 18 sulfur or nitrogen bonds, a is 2 to 10, or R 4 is HSR 1 O(CH 2 CHR 2 O) n R 1 S, a is 1, R 5 is bisphenol A, or bisphenol F, or bisphenol S, or biphenyl, or a halogenated bisphenol, or an aliphatic chain having 1 to 18 carbon atoms; and m is 0 to 18.

[0099] 3. The curable composition of embodiment 1 or 2, wherein the epoxy resin comprises an internally flexible bisphenol epoxy resin.

[0100] 4. The internal flexible bisphenol epoxy resin has the following formula: [ka] 4. The curable composition of embodiment 3, represented by the formula: wherein Ar is bisphenol A, bisphenol F, bisphenol Z, or a mixture thereof.

[0101] 5. The curable composition according to any one of embodiments 1 to 4, wherein the epoxy resin comprises a phosphonic acid group in its backbone.

[0102] 6. The curable composition of any one of embodiments 1 to 5, wherein the epoxy resin further comprises a rigid bisphenol epoxy resin.

[0103] 7. The curable composition of embodiment 6, wherein the rigid bisphenol epoxy resin is present in the curable composition in an amount of less than 50 wt%, based on the total weight of the epoxy resin.

[0104] 8. The curable composition according to any one of embodiments 1 to 7, further comprising a silane coupling agent.

[0105] 9. The curable composition of embodiment 8, wherein the silane coupling agent comprises an amine-terminated silane coupling agent.

[0106] 10. The curable composition of embodiment 8, wherein the silane coupling agent comprises a mercaptan-terminated silane coupling agent.

[0107] 11. The curable composition of embodiment 8, wherein the silane coupling agent comprises an epoxy-terminated silane coupling agent.

[0108] 12. The curable composition of any one of embodiments 1 to 11, further comprising a catalyst.

[0109] 13. The curable composition of embodiment 12, wherein the catalyst comprises a basic catalyst.

[0110] 14. The basic catalyst has the formula: [ka] or [ka] 14. The curable composition of embodiment 13, represented by one of:

[0111] 15. The curable composition of embodiment 13, wherein the basic catalyst comprises a tertiary amine and a primary amine in the backbone.

[0112] 16. A basic catalyst having the formula: [ka] 14. The curable composition of embodiment 13, represented by:

[0113] 17. The curable composition of embodiment 12, wherein the catalyst comprises a Lewis acid catalyst.

[0114] 18. The curable composition of embodiment 12, wherein the Lewis acid catalyst comprises calcium triflate, calcium nitrate, or a tin catalyst.

[0115] 19. The curable composition of any one of embodiments 1-18, wherein the epoxy resin is present in the curable composition in an amount of at least 20% by weight, based on the total weight of the unfilled curable composition.

[0116] 20. The curable composition of any one of the preceding embodiments, wherein the multifunctional thiol-containing compound is present in the curable composition in an amount of 4.9 to 20% by weight, based on the total weight of the unfilled curable composition.

[0117] 21. The curable composition of any one of embodiments 1 to 20, further comprising a multifunctional amine.

[0118] 22. The curable composition of any one of the preceding embodiments, wherein the inorganic filler is present in an amount of at least 50% by weight, based on the total weight of the curable composition.

[0119] 23. The curable composition of any one of embodiments 1-22, wherein the inorganic filler is present in an amount of at least 60% by weight, based on the total weight of the curable composition.

[0120] 24. The curable composition of any one of embodiments 1 to 23, wherein the inorganic filler comprises alumina.

[0121] 25. The curable composition of any one of embodiments 1 to 24, wherein the inorganic filler comprises spherical alumina particles or hemispherical alumina particles.

[0122] 26. The curable composition of any one of embodiments 1 to 25, wherein the inorganic filler comprises silane surface-treated particles.

[0123] 27. The curable composition of any one of embodiments 1 to 26, wherein the inorganic filler comprises ATH.

[0124] 28. The curable composition, when cured, has (i) an elongation at break of 9% or more, and (ii) a strength of 3 to 20 N / mm on untreated aluminum. 2 28. The curable composition according to any one of embodiments 1 to 27, having an overlap shear strength of

[0125] 29. The curable composition, upon curing, has (i) an elongation at break of 15% or more, and (ii) a compressibility of 3 to 20 N / mm on untreated aluminum. 2 29. The curable composition of any one of embodiments 1 to 28, having an overlap shear strength of

[0126] 30. When the curable composition is cured, it has a compressive strength of 1 to 16 N / mm 2 30. The curable composition according to any one of embodiments 1 to 29, having a tensile strength of

[0127] 31. The curable composition, upon curing, has a thermal conductivity of at least 1.0 W / (m * The curable composition according to any one of embodiments 1 to 30, having a thermal conductivity of 0.1 to 0.5 K.

[0128] 32. An article comprising a cured composition, the cured composition being a reaction product of the curable composition of any one of embodiments 1-31.

[0129] 33. The article of embodiment 32, wherein the cured composition has a thickness of from 5 microns to 10,000 microns.

[0130] 34. The article of embodiment 32 or 33, further comprising a substrate having a surface, the cured composition being disposed on the surface of the substrate.

[0131] 35. The article of embodiment 34, wherein the substrate is a metal substrate.

[0132] 36. 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 described in any one of embodiments 1-31.

[0133] 37. A battery module comprising a plurality of battery cells connected to a first base plate by a first layer of the reaction product of the curable composition according to any one of embodiments 1-31.

[0134] 38. A method for manufacturing a battery module, comprising: applying a first layer of a curable composition described in any one of embodiments 1-31 to a first surface of a first base plate; attaching a plurality of battery cells to the first layer to connect the battery cells to the first base plate; and curing the curable composition. EXAMPLES

[0135] Objects and advantages of the present disclosure are further illustrated by the following comparative examples and examples. All parts, percentages, ratios, etc. in the examples and the remainder of the specification are by weight unless otherwise noted. All reagents used in the examples were obtained or are available from general chemical suppliers, such as, for example, Sigma-Aldrich Corp., Saint Louis, MO, US, unless otherwise indicated.

[0136] Synthesis of polyfunctional thiols Table 1 summarizes the materials used for the multifunctional thiols. [Table 1]

[0137] Thiol-1 (Synthesis of Multifunctional Thiol-1) Thiol-1 was prepared as follows: 14.5 g of DER331, 18.5 g of DMDO, 14.5 g of PETMP, and 2.5 g of tris-2,4,6-(dimethylaminomethyl)phenol were added to a reactor. The mixture was stirred with an agitator (3-swept blade agitator) in the reactor at a rotation speed of about 75 rpm for 24 hours. The reactor was kept at room temperature. PETMP has the following formula: wherein x is 4.

[0138] Thiol-2 (Synthesis of multifunctional thiol-2) Thiol-2 is a reaction product of 23 g of DER331, 21.25 g of DMDO, 2 g of tetraethylenepentamine, and 3.75 g of N,N-dimethylethylenediamine. The synthesis method is the same as that of thiol-1. Tetraethylenepentamine has the following formula: [In the formula, R 15 is a nitrogen-containing aliphatic chain.

[0139] Thiol-3 (Synthesis of multifunctional thiol-3) Thiol-3 is a reaction product of 23 g of DER331, 21.5 g of DMDO (Arkema), 4 g of 1,8-diamino-3,6-dioxaoctane, and 2.5 g of N,N-dimethylethylenediamine. The synthesis method is the same as that of thiol-1. 1,8-diamino-3,6-dioxaoctane has the following formula: [In the formula, R 15 is an oxygen-containing aliphatic chain.

[0140] Thiol-4 (Synthesis of multifunctional thiol-4) Thiol-4 is the reaction product of 23.5g DER331, 19g DMDO, 5g 1,8-diamino-3,6-dioxaoctane, and 2.5g N,N-dimethylethylenediamine. The synthesis method is the same as that of thiol-1. The crosslinker present in thiol-4 is the same crosslinker as that in thiol-3, and the amount is more abundant than that of thiol-3.

[0141] Thiol-5 (Synthesis of multifunctional thiol-5) Thiol-5 is the reaction product of 21.25g DER331, 22.5g DMDO, and 6.25g N,N-dimethylethylenediamine. The synthesis method is the same as that of thiol-1. Thiol-5 does not contain any crosslinker.

[0142] Thiol-6 (Synthesis of multifunctional thiol-6) Thiol-6 is the reaction product of 26.25g of XY207, 16.75g of DMDO, 2g of tetraethylenepentamine, and 5g of N,N-dimethylethylenediamine. The synthesis method is the same as that of Thiol-1. XY207 is an aliphatic epoxy.

[0143] Thiol-1 to thiol-6 are as follows: 1. HSR 1 O(CH 2 CHR 2 O) n R 1 SH[where each R 1 each independently represents an alkylene group having 2 to 12 carbon atoms; 2 are independently H or CH 3 and n represents an integer of 1 to 20. 2. An epoxy resin, comprising an aliphatic epoxy containing an aliphatic chain having 1 to 18 carbon atoms, a bisphenol epoxy, the bisphenol epoxy may comprise bisphenol A epoxy, bisphenol F epoxy, bisphenol S epoxy, halogenated bisphenol epoxy, or a combination thereof; 3. Any crosslinking agent, including a reaction product of a component comprising a crosslinking agent, including a polyfunctional thiol or a polyfunctional amine.

[0144] Thiol-1 to Thiol-6 disclose a method for synthesizing a polyfunctional thiol-containing compound, which has the following formula: [ka] [Wherein, independently, R 3 is R 1 O(CH 2 CHR 2 O) n R 1 and R 4 is a branched aliphatic chain containing 2 to 18 sulfur or nitrogen bonds, a is 2 to 10, or R 4 is HSR 1 O(CH 2 CHR 2 O) n R 1 S, a is 1, R 5 is bisphenol A, or bisphenol F, or bisphenol S, or biphenyl, or a halogenated bisphenol, or an aliphatic chain having 1 to 18 carbon atoms; and m is 0 to 18.

[0145] In the above formula, R 3 is HSR 1 O(CH 2 CHR 2 O) n R 1 Obtained from SH, R 4 Any crosslinker (multifunctional thiol or multifunctional amine) or bifunctional thiol HSR 1 O(CH 2 CHR 2 O) n R 1 Obtained from SH, R 5 is derived from epoxy resin.

[0146] The formula is one of the possible formulas for the reacting compound. The reacting compound may have a more complex net structure.

[0147] Sample preparation Table 2 summarizes the materials used in the examples. [Table 2]

[0148] Detailed formulations of Examples 1-16 are listed in Tables 3 and 4.

[0149] To prepare the samples, parts A and B were mixed separately as follows: First, the organic components were combined and mixed by hand. The thixotropic additive was then added, followed by hand mixing. The materials were then thoroughly mixed using a speed mixer (SPEEDMIXER DAC 400, FlackTek, Inc., Landrum, SC, US) at 1500 rpm for 2 minutes. The remaining filler materials were combined and added to the formulation in two portions. The addition of each portion was followed by mixing in the DAC 400 mixer at 2000 RPM for 2 minutes. In the final step, the materials were mixed in the DAC 400 mixer at 1500 RPM for 15 seconds at atmospheric pressure, then at 30 Torr and 2000 RPM for 2 minutes, then mixed for a final 15 seconds at 1500 RPM as pressure was returned to atmospheric pressure.

[0150] Parts A and B were mixed based on the stoichiometric ratio of functional groups: moles of thiol groups in Part A, and the combined moles of epoxide groups in Part B. Parts A and B were mixed in the ratios listed in Tables 3 and 4 using an air dispenser system with a static mixing nozzle. [Table 3] [Table 4]

[0151] Test procedure Overlap shear strength (OLS) Two 1 inch (2.54 centimeters (cm)) wide x 4 inch (10 cm) long x 0.125 inch (0.32 cm) thick aluminum coupons were cleaned using methyl ethyl ketone (MEK) and otherwise left untreated. At the tip of one coupon, a 1 inch x 0.5 inch (2.54 cm x 1.27 cm) rectangle was covered with the mixed thiol / epoxy paste and then laminated with another coupon in the opposite tip direction to obtain approximately 10 to 30 mils (0.25 to 0.76 millimeters (mm)) of paste between the aluminum coupons, which were clamped with binder clips. The laminated aluminum coupons were then allowed to overcure at room temperature for 2 days to obtain a full cure before overlap shear testing.

[0152] OLS testing was performed on an INSTRON Universal Testing Machine model 1122 (INSTRON Corporation, Norwood, MA, USA) according to the procedure of ASTM D1002-01, "Standard Test Method for Apparent Shear Strength of Single-Lap-Joint Adhesively Bonded Metal Specimens by Tension Loading (Metal-to-Metal)". The crosshead speed was 0.05 in / min (1.27 mm / min).

[0153] Tensile and elongation properties For tensile strength and elongation testing, dog-bone shaped samples were made according to ASTM D1708-13, "Standard Test Method for Tensile Properties of Plastics by Use of Microtensile Specimens," by pressing the mixed paste into a dog-bone shaped silicone rubber mold, then laminated with release liners on both sides. The dog-bone shape gives a sample with a length of about 0.6 inches (1.5 cm) at the center straight region, a width of about 0.2 inches (0.5 cm) at the narrowest region, and a thickness of about 0.06 to about 0.1 inches (about 1.5 mm to about 2.5 cm). The samples were then cured at room temperature for 24 hours, at 100°C for 1 hour, or at 120°C for 1 hour to fully cure before tensile testing. The samples were then conditioned at room temperature for 30 minutes before tensile and elongation testing.

[0154] Tensile strength and elongation tests were performed on an INSTRON Universal Testing Machine model 1122 (INSTRON Corporation, Norwood, MA, US) according to ASTM D638-14, "Standard Test Method for Tensile Properties of Plastics". The crosshead speed was 0.04 in / min (1 mm / min). The elastic modulus was calculated from the slope of the linear portion of the stress-strain curve.

[0155] Thermal Conductivity For thermal conductivity measurements, disk-shaped samples were made by pressing the mixed paste into a disk-shaped silicone rubber mold, then laminated with release liners on both sides. The disk shape gives a sample with a diameter of 12.6 mm and a thickness of 2.2 mm. The samples were then cured at room temperature for 24 hours, room temperature for 15 hours, or at 100°C for 1 hour to obtain full cure.

[0156] Specific heat capacity, C pwas measured using a Q2000 differential scanning calorimeter (TA Instruments, Eden Prairie, Minn., US) with sapphire as the method standard.

[0157] The sample density was determined using a geometric method. The weight (m) of the disk-shaped sample was measured using a standard laboratory balance, the diameter (d) of the disk was measured using a caliper, and the thickness (h) of the disk was measured using a Mitatoyo micrometer. The density, ρ, was determined using

number

[0158] Thermal diffusivity, α(T), was measured using an LFA 467 HYPERFLASH Light Flash Apparatus (Netzsch Instruments, Burlington, MA, US) according to ASTM E1461-13, “Standard Test Method for Thermal Diffusivity by the Flash Method.”

[0159] Thermal conductivity k is calculated using the formula:

number

[0160] Electrical resistivity Surface and volume resistivities were measured using a Model 6517A electrometer (Keithley Instruments, Cleveland, OH, US) with 100 femtoamp resolution and 500 volts applied voltage according to the procedures of ASTM D257-14, "Standard Test Methods for DC Resistance or Conductance of Insulating Materials." A Keithley Model 8009 Resistivity test fixture was used with compressible conductive rubber electrodes and an electrode pressure of 1 pound for approximately 2.5 inches of electrode and sample. The samples were approximately 18 mils thick. The corresponding detection threshold for surface resistivity is approximately 1017 ohms. Each sample was measured once and a current time of 60 seconds was used. A high resistivity sample PTFE, a low resistivity sample (bulk loaded carbon in Kapton), and a medium resistivity sample (paper) were used as material reference standards.

[0161] result Table 5 summarizes the extension and overlap shear adhesion properties of Examples 1-16.

[0162] By using these multifunctional thiols disclosed in the present disclosure, the curable compositions of Examples 1 to 16 have good overlap shear adhesion properties (3 N / mm 2 ~20N / mm 2 ) and at the same time showed high thermal conductivity (total thermal conductive filler addition amount was 60 wt % or more).

[0163] When the content of the multifunctional thiol was 5% by weight to 20% by weight (based on the total weight of the curable composition), Examples 1 to 7 showed good overlap shear adhesion properties (5 N / mm 2 It exhibited high elongation at break (9% or more) with a high elongation at break (>9%).

[0164] This is because the rigid bisphenol epoxy resin (EPON 828) is present in Examples 4 to 6 in an amount of less than 50% by weight, based on the total weight of the epoxy resin. Examples 4 to 6 have good overlap shear adhesion properties (7 N / mm 2 It showed better elongation at break (above 16%) with higher elongation at break (above 16%). [Table 5]

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

Claims

1. A two-part curable composition comprising: A first agent containing an epoxy resin; a second agent comprising a polyfunctional thiol-containing compound; an inorganic filler provided via the first agent, the second agent, or both, or separately from the first agent and the second agent; the epoxy resin is present in an amount of at least 20 wt%, based on the total weight of the two-part curable composition; the multifunctional functional thiol-containing compound is present in an amount of 4.9 to 20 wt.%, based on the total weight of the two-part curable composition; the inorganic filler is present in an amount of at least 40 wt.%, based on the total weight of the two-part curable composition; The functional thiol-containing compound may have 2 to 10 thiol functional groups and is selected from the group consisting of: a)HSR １ O(CH ２ CHR ２ O) ｎ R １ SH [In the formula, Each R １ independently represent an alkylene group having 2 to 12 carbon atoms; Each R ２ are independently H or CH ３ represents n represents an integer from 1 to 20; b) an epoxy resin different from that contained in the first agent, the epoxy resin including an aliphatic epoxy containing an aliphatic chain having 1 to 18 carbon atoms, a bisphenol epoxy, the bisphenol epoxy may include bisphenol A epoxy, bisphenol F epoxy, bisphenol S epoxy, halogenated bisphenol epoxy, or a combination thereof; c) an optional crosslinker, comprising a multifunctional thiol or a multifunctional amine; 1. A two-part curable composition comprising the reaction product of components comprising:

2. The multifunctional functional thiol-containing compound has the following formula: 【Chemistry 1】 [Wherein, independently, R ３ is R １ O (CH ２ CHR ２ O) ｎ R １ and R ４ is a branched aliphatic chain containing 2 to 18 sulfur or nitrogen bonds, a is 2 to 10, or R ４ is HSR １ O (CH ２ CHR ２ O) ｎ R １ S, a is 1, R ５ is bisphenol A, or bisphenol F, or bisphenol S, or biphenyl, or a halogenated bisphenol, or an aliphatic chain having 1 to 18 carbon atoms; The two-part curable composition according to claim 1, wherein m is an integer of 0 to 18.

3. The epoxy resin of the first agent has the following formula: 【Chemistry 2】 3. The two-part curable composition of claim 1 or 2, comprising an internally flexible bisphenol epoxy resin represented by the formula: wherein Ar is bisphenol A, bisphenol F, bisphenol Z, or a mixture thereof.

4. The two-part curable composition according to any one of claims 1 to 3, wherein the epoxy resin of the first part contains a phosphonic acid group in its main chain.

5. The two-part curable composition according to any one of claims 1 to 4, further comprising an amine-terminated silane coupling agent, a mercaptan-terminated silane coupling agent, or an epoxy-terminated silane coupling agent, provided via the first part, the second part, or both, or separately from the first part and the second part.

6. 6. An article comprising a cured composition, said cured composition being a reaction product of the two-part curable composition of any one of claims 1 to 5.

7. 7. The article of claim 6, comprising a first substrate, a second substrate, and the cured composition disposed between the first substrate and the second substrate and adhering the first substrate to the second substrate.

8. 7. The article of claim 6, which is a battery module comprising a plurality of battery cells connected to a first base plate by a first layer of a reaction product of the two-part curable composition.

9. 6. A method of manufacturing a battery module, comprising: applying a first layer of the two-part curable composition of any one of claims 1 to 5 to a first surface of a first base plate; attaching a plurality of battery cells to the first layer to connect the battery cells to the first base plate; and curing the curable composition.

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