Providing a preparation of a thermally conductive adhesive formulation for bonding battery cells

Abstract

The invention relates to the technical field of batteries for electric vehicles and adhesive formulations for assembling the latter in vehicles. The invention relates to a preparation for providing a thermally conductive adhesive formulation, to a method for producing said preparation, to a structure consisting of at least one battery cell, an adhesive layer and a heat sink, and to a method for producing the structure of the invention.

Description

Technical Field

[0001] This invention relates to the technical field of electric batteries and adhesive formulations for assembling them in vehicles. The invention further relates to preparations for providing thermally conductive adhesive formulations, methods for producing said preparations, structures comprising at least one battery cell, an adhesive layer, and a heat sink, and a method for producing the structure of the invention. Background Technology

[0002] Batteries used in electric vehicles consist of many individual battery cells, where electrochemical reactions take place to generate and store electricity. These battery cells are first connected in series to form so-called battery modules; these modules are then assembled into a so-called battery pack. To regulate the temperature of the individual modules, they are typically arranged on a cooling plate that can be actively cooled / heated. For effective temperature regulation, heat transfer between the cooling plate and the battery modules must be maximized. For this reason, the battery modules are typically bonded to the cooling plate with a thermally conductive adhesive (also known as a gap filler). Suitable adhesives typically consist of a curing agent component (e.g., a polyurethane- or silyl-modified polymer) containing a high concentration of thermally conductive fillers (such as Al₂O₃ or Al(OH)₃). Filler concentrations up to 90% by weight are not uncommon. During battery production, the adhesive is typically applied to the cooling plate in paste form, after which the battery modules are installed. It is important that the adhesive is easy to apply despite the high filler content; on the other hand, it is important that the adhesive spreads into a completely sealed layer when the modules are installed to avoid the formation of thermal bridges. To meet these requirements, dispersing additives are often used in such highly filled adhesives to control the flow properties of the system. However, the dispersing additives available to date are not optimized for the aforementioned applications, and therefore there remains great interest in custom additives for thermally conductive adhesives.

[0003] Purpose of the invention Therefore, an object of the present invention is to satisfy the requirements outlined in the introduction. Another object of the present invention is to overcome the disadvantages of the prior art.

[0004] Therefore, one object is to provide a preparation for providing a thermally conductive adhesive formulation, such as a preparation of a formulation based on a polyurethane or silyl-modified polymer, said preparation being highly filled with a thermally conductive solid such as Al2O3 or Al(OH)3. Summary of the Invention

[0005] The object of the present invention is achieved by the preparation of the present invention for providing a thermally conductive adhesive formulation, the preparation comprising... I) At least one component selected from isocyanates and polymers; and II) At least one filler; and III) At least one dispersant corresponding to formula (1) R 1 -A m -B n -R 2 (1), in m is an integer in the range of 1 to 45, preferably 1 to 25; n is an integer in the range of 0 to 20, preferably 1 to 20; R 1 It is a monovalent aliphatic saturated or unsaturated hydrocarbon group having 1 to 39, preferably 3 to 39, more preferably 7 to 21, and most preferably 8 to 17 carbon atoms; R 2 Selected from -OH, -OR 3 and (R) 4 O)2P(O)-, in R 3 It is an alkyl group. Each R 4 Independently selected from cations, H, monovalent aliphatic saturated or unsaturated hydrocarbon groups having 1 to 39 carbon atoms, preferably 3 to 39, more preferably 7 to 22, and most preferably 9 to 18 carbon atoms, and in the form of R. 1 -A m -B n - group; Each A is an independent unit of a group of formula (1A): (1A), Where X 1 and X 2 Selected from hydrogen and methyl, under the condition X 1 and X 2 At least one of them is hydrogen; and Each B is an independent unit of a group of formula (1B): (1B), Where Y 1 and Y 2 Selected from hydrogen and phenyl, under the condition that Y 1 and Y 2 One of them is hydrogen.

[0006] The preparations of the present invention and the adhesive formulations provided therefrom exhibit high stability. They also do not exhibit precipitation, inhomogeneity, or other optical defects that could lead to uneven application. They are advantageous for easy application, for example, as a paste.

[0007] Furthermore, the (thermally conductive) filler is better distributed in the preparations and adhesive formulations of the present invention than in solutions proposed in the prior art. This advantageously achieves improved thermal conductivity (e.g., compared to the same amount of filler) in the adhesive formulation and the adhesive layer therefrom. Attached Figure Description

[0008] Figure 1 The graph shows the shear rate-viscosity relationship for experimental formulations #1, #2, and #3. In this graph, experiment #1 is shown as a solid line, experiment #2 as a dashed line, and experiment #3 as a dotted line.

[0009] Figure 2 The graph shows the shear rate-viscosity relationship for experimental formulations #4, #5, and #6. In this graph, experiment #4 is shown as a solid line, experiment #5 as a dashed line, and experiment #6 as a dotted line.

[0010] Figure 3 The graph shows the shear rate-viscosity relationship for experimental formulations #7, #8, and #9. In this graph, experiment #7 is shown as a solid line, experiment #8 as a dashed line, and experiment #9 as a dotted line.

[0011] Figure 4 (Schematic diagram, not to scale) The structure of the present invention is shown, which includes eight battery cells (3), an adhesive layer (2) and a heat sink (1). The adhesive layer (2) is disposed between the battery cells (3) and the heat sink (1). Invention Details Percentages in the specification and claims are weight percentages (abbreviated as weight %) unless otherwise stated. Concentrations in the specification and claims refer to the total mass or total volume of the solution, dispersion, or composition under discussion unless otherwise stated. The terms "preparation" and "composition" should be understood as synonyms for the purposes of this invention.

[0013] The various details and implementation schemes described below can be combined with each other, provided that this is technically possible and the opposite is not specified.

[0014] The term "aliphatic" for the purposes of this invention includes cyclic and acyclic (acyclic), saturated and unsaturated carbon compounds, while aromatic compounds are explicitly excluded under this term (see Compendium of Technical Terminology, Gold Book, International Union of Pure and Applied Chemistry, 2014, version 2.3.3, p. 57).

[0015] The term "alkyl" for the purposes of this invention includes branched and unbranched alkyl groups, including cyclic and / or acyclic structural elements, wherein the cyclic structural element comprises at least three carbon atoms by definition. C1-C1 alkyl in the specification and claims refers to an alkyl group containing 1 to X carbon atoms (X is a natural number). For example, C1-C8 alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, tert-pentyl, neopentyl, hexyl, heptyl, and octyl.

[0016] When more than one functional group needs to be selected for a compound named in the claims or specification, unless otherwise stated, the functional groups are selected independently of each other, whether the selections are from one or more lists. Therefore, they can be the same or different if the lists allow.

[0017] When the term "at least one" is stated in the specification and claims, it means that one or more of the elements may be selected, such as two or three. The same applies to higher numbers, such as two or three.

[0018] The preparations of the present invention comprise (or consist of) the following: I) at least one component selected from isocyanates and polymers; and II) At least one filler; and III) At least one dispersing agent corresponding to formula (1).

[0019] The at least one component is selected from isocyanates and polymers. This component is referred to herein as "Component I".

[0020] Suitable isocyanates have at least two NCO groups ("isocyanate groups") and are selected from the group consisting of aliphatic, cycloaliphatic, aryliphatic or aromatic isocyanates. Preferred aromatic isocyanates are selected from the group consisting of toluene 2,4-diisocyanate, diphenylmethane 4,4'-diisocyanate (4,4'-MDI), diphenylmethane 2,4'-diisocyanate (2,4'-MDI), diphenylmethane 2,2'-diisocyanate (2,2'-MDI), urethane-modified liquid diphenylmethane 4,4'-diisocyanate, urethane-modified liquid diphenylmethane 2,4'-diisocyanate, urethane-modified liquid diphenylmethane 2,2'-diisocyanate, higher polycyclic homologues of diphenylmethane diisocyanate (also known as oligomers, polymers, or industrial MDI), naphthylene 1,2-diisocyanate, naphthylene 1,5-diisocyanate, and mixtures thereof, with particular preference for MDI and / or polymeric MDI.

[0021] Suitable aliphatic or cycloaliphatic isocyanates are selected from the group consisting of tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene-1,5-diisocyanate, 2-ethylbutylene-1,4-diisocyanate, 1-isocyano-3,3,5-trimethyl-5-isocyanomethylcyclohexane (isophorone diisocyanate, IPDI), 1,3-bis(isocyanomethyl)cyclohexane (HXDI), cyclohexane 1,4-diisocyanate, 1-methylcyclohexane 2,4-diisocyanate, 1-methylcyclohexane 2,6-diisocyanate, dicyclohexylmethane 4,4'-diisocyanate, dicyclohexylmethane 2,4'-diisocyanate, dicyclohexylmethane 2,2'-diisocyanate, and mixtures thereof.

[0022] The at least one polymer (component I) is preferably selected from polyols, polyethers, polyurethane prepolymers and silyl-modified polymers.

[0023] The polyol is preferably selected from polyester polyols, polyether polyols, and polycarbonate polyols, as well as mixtures thereof. For example, the polyol contains 2 to 6, preferably 2 to 4 (NCO reactive) OH functional groups.

[0024] Suitable polyethers are known to those skilled in the art. They are preferably produced by the addition reaction of alkyl epoxides such as ethylene oxide or propylene oxide with an initiator having at least two active hydrogen atoms. Examples of such initiators are polyols (e.g., ethylene glycol, propylene glycol, glycerol, trimethylolpropane, or pentaerythritol), aliphatic amines (e.g., ethylenediamine), aromatic amines (e.g., toluenediamine), and alkanolamines (e.g., ethanolamine and diethanolamine), as well as sugars (e.g., sorbitol, glucose, and sucrose). The addition reaction can be carried out according to the method described on pages 42-53 of Gunter Oertel, Hanser Verlag Deutschland, (1985), "Polyurethane Handbook".

[0025] Suitable polyester polyols are also known to those skilled in the art. They are preferably prepared by reacting at least one diacid with at least one polyol. The at least one diacid is preferably selected from picric acid, maleic acid, phthalic acid, and terephthalic acid. As the polyol, diols are preferred, and the diols are preferably selected from ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, and cyclohexane-1,4-diethanol.

[0026] Suitable polymeric polyols are also known to those skilled in the art. They are preferably obtained by reacting the aforementioned polyether polyols with olefinically unsaturated monomers such as butadiene, acrylonitrile, or styrene in the presence of a free radical initiator.

[0027] Suitable polycarbonate polyols are also known to those skilled in the art. They are preferably prepared by reacting a polyol (typically a diol, preferably selected from ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, and cyclohexane-1,4-diethanol) with at least one carbonate (preferably dimethyl carbonate or diphenyl carbonate), followed by removal of excess carbonate and the released monool to expose terminal OH groups. Alternatively, polycarbonate polyols can be obtained by the direct reaction of a diol with carbon dioxide in the presence of a suitable catalyst.

[0028] Suitable polyether polyols preferably have a weight-average molecular weight (M) of 750 to 6000 g / mol. w Weight-average molecular weight (M) w Preferably, the assay can be performed by gel permeation chromatography (GPC) using an SDV 1000 / 10000 Å column combination (length: 65 cm) at 30 °C with THF as the mobile phase, and at a flow rate of 1 ml / min, a sample concentration of 10 g / L, and an RI detector calibrated with polypropylene glycol as a standard.

[0029] Suitable polyester polyols preferably have a weight-average molecular weight (M) of 100 to 2500 g / mol. wThe molecular weight can be determined by GPC as described above.

[0030] Preferably, the polyol has an OH value in the range of 20 to 1000 mg KOH / g. Preferred polyether polyols have an OH value in the range of 20 to 800 mg KOH / g. Preferred polyester polyols have an OH value in the range of 40 to 1000 mg KOH / g. Suitable methods for determining the hydroxyl value are particularly those according to DGF CV 17a (53) and Ph. Eur. 2.5.3 Method A.

[0031] Suitable polyurethane prepolymers are also known to those skilled in the art. They are preferably obtained by reacting at least one isocyanate with a substoichiometric amount of at least one polyol. The reaction is preferably carried out at a temperature of 30 to 100°C. The corresponding polyurethane prepolymers have at least two reactive NCO groups.

[0032] Silyl-modified polymers are known to those skilled in the art and are typically formed of three structural units: a polymer backbone, at least two linking groups, and at least two condensable alkoxysilyl groups, each of which is connected to the polymer backbone via one of the linking groups. The polymer backbone is preferably selected from polyether polyols (preferably based on polyethylene glycol and polypropylene glycol), polyesters, polycarbonates, polyacrylates, polyolefins, polyurethanes, and mixtures thereof. Polyether polyols are particularly preferred. Preferred linking groups are selected from alkyl groups, carbamate groups, urethane groups, and urea groups. The condensable alkoxysilyl groups are preferably selected from dimethoxysilyl, trimethoxysilyl, diethoxysilyl, or triethoxysilyl.

[0033] The preparation of the present invention comprises at least one component I, preferably in an amount of 1 to 49% by weight, more preferably 5 to 29% by weight, and even more preferably 10 to 19% by weight, based on the total mass of the preparation. If more than one component I is used, its total mass is preferably within one of the ranges defined above.

[0034] The preparations of the present invention comprise at least one filler. The filler is particularly used to ensure that the adhesive layer produced from the preparations of the present invention or from the adhesive formulations described below has sufficient thermal conductivity after application. Many fillers suitable for this purpose are known to those skilled in the art. Preferably, the filler has a thermal conductivity of at least 10 W / m³. -1 K -1 More preferably at least 12 W m -1 K -1 The optimal value is at least 15 W m -1 K -1The thermal conductivity is considered. The filler is preferably selected from metallic fillers, ceramic fillers, carbon-based fillers, and mixtures of the above. Preferred metallic fillers are silver and copper. Preferred carbon-based fillers are graphite and carbon black. Preferred ceramic fillers are alumina, aluminum hydroxide, aluminum hydroxya, and boron nitride. Ceramic fillers are preferred because they allow good thermal conductivity but have low electrical conductivity. This prevents the risk of short circuits and battery damage. Particularly preferably, the at least one filler is selected from alumina, aluminum hydroxide, and aluminum hydroxya. Most preferably, the at least one filler is alumina or aluminum hydroxide.

[0035] Preferably, the at least one filler is present in particulate form. A bimodal or multimodal particle size distribution is preferred. Preferably, the particle size (d) of the at least one filler is... 90 The particle size is 0.5 to 500 µm, preferably 1 to 250 µm, and more preferably 5 to 150 µm. The particle size can be determined by laser diffraction, for example using a Mastersizer 3000 from Malvern.

[0036] The preparations of the present invention comprise at least one filler, preferably in an amount of 50 to 99% by weight, more preferably 70 to 95% by weight, and even more preferably 80 to 90% by weight, based on the total mass of the preparation. If more than one filler is used, its total mass is preferably within one of the ranges defined above. A low proportion of the at least one filler may sometimes result in a binder layer with too low thermal conductivity, while a high proportion may potentially result in a layer with too low adhesion.

[0037] The at least one dispersing agent corresponds to formula (1): R 1 -A m -B n -R 2 (1), in m is an integer in the range of 1 to 45, preferably 1 to 25; n is an integer in the range of 0 to 20, preferably 1 to 20; R 1 It is a monovalent aliphatic saturated or unsaturated hydrocarbon group having 1 to 39, preferably 3 to 39, more preferably 7 to 21, and most preferably 8 to 17 carbon atoms; R 2 Selected from -OH, -OR 3 and (R) 4 O)2P(O)-, in R 3 It is an alkyl group. Each R 4Independently selected from cations, H, monovalent aliphatic saturated or unsaturated hydrocarbon groups having 1 to 39 carbon atoms, preferably 3 to 39, more preferably 7 to 22, and most preferably 9 to 18 carbon atoms, and in the form of R. 1 -A m -B n - group; Each A is an independent unit of a group of formula (1A): (1A), Where X 1 and X 2 Selected from hydrogen and methyl, under the condition X 1 and X 2 At least one of them is hydrogen; and Each B is an independent unit of a group of formula (1B): (1B), Where Y 1 and Y 2 Selected from hydrogen and phenyl, under the condition that Y 1 and Y 2 One of them is hydrogen and the other is phenyl.

[0038] For the purposes of this invention, a monovalent group means that the group is capable of forming a bond (with another bonded pair). Preferably, m is selected from the range of 3 to 20, more preferably from the range of 5 to 15. Preferably, n is selected from the range of 2 to 15, more preferably from the range of 3 to 10. Preferably, R 1 It is an alkyl group, more preferably a C7-C21 alkyl group, and even more preferably a C8-C17 alkyl group. Preferably, X 1 and X 2 Both are hydrogen. R 2 Preferably selected from -OH and (R 4 O)2P(O)-. Even more preferably, R 2 It is an -OH group.

[0039] R 3 Preferably C1-C4 alkyl, more preferably methyl or ethyl.

[0040] R 4 The cation is typically a monovalent cation (or a corresponding fragment of a polyvalent cation). Preferred cations are selected from alkali metal ions (preferably Na+). + K + ), ammonium ions (NH4) +Ammonium ions of monoalkylamines, dialkylamines, and trialkylamines, wherein the alkyl group may also be functionalized, for example, in the case of amide amines, ammonium ions of monoalkylolamines, dialkylolamines, and trialkylolamines, and ammonium ions of monoaminoalkylamines, diaminoalkylamines, and triaminoalkylamines.

[0041] R 4 The hydrocarbon group has 1 to 39 carbon atoms, preferably 3 to 39, more preferably 7 to 22, and most preferably 9 to 18 carbon atoms. It is preferably an alkyl group, more preferably an alkyl group having one of the above-mentioned numbers of carbon atoms.

[0042] Preferably, m is selected from the range of 3 to 20 (more preferably from the range of 5 to 15), n is selected from the range of 2 to 15 (more preferably from the range of 3 to 10), and R 1 It is a C7-C21 alkyl group (more preferably a C8-C17 alkyl group), and X 1 and X 2 Both are hydrogen.

[0043] The stereoregularity of A and B is not limited in principle. Preferably, A and B have atactic stereoregularity or block stereoregularity. More preferably, the at least one dispersant corresponding to formula (1) contains blocks of A and B. Particularly preferably, it contains blocks connected to R 1 The A block between the B block and the B block.

[0044] Dispersants corresponding to formula (1) and their preparation are known, for example from EP 0 378 048 A1. The introduction of the (R4O)2P(O) unit can be achieved by known reactions (e.g., phosphorylation with phosphorus pentoxide or polyphosphoric acid).

[0045] The preparation preferably contains at least one dispersant corresponding to formula (1) in an amount of 0.1 to 10.0% by weight, more preferably 0.5 to 5.0% by weight, and even more preferably 1.0 to 3.0% by weight, based on the total mass of the preparation. If more than one dispersant corresponding to formula (1) is used, its total mass is preferably within one of the ranges defined above.

[0046] The present invention also relates to the use of dispersants corresponding to formula (1) for improving the rheological properties and / or stability of polymer dispersions or adhesive formulations. In particular, the use of dispersants corresponding to formula (1) makes it possible to improve the rheological properties of adhesive formulations capable of producing thermally conductive adhesive layers. For polymer dispersions or adhesive formulations according to the present invention, particularly thermally conductive adhesive layers, the improvement is particularly a reduction in viscosity. The adhesive formulation preferably contains fillers from the group described above, in one of the amounts mentioned herein, and is preferably a thermally conductive adhesive formulation.

[0047] The present invention also relates to a method for producing the preparations of the present invention, comprising the following method steps: M1) provides at least one component (component I) selected from isocyanates and polymers; M2) provides at least one type of filler; M3) provides at least one dispersing agent corresponding to formula (1); and M4) Mix the at least one component I, the at least one filler and the at least one dispersant corresponding to formula (1); The prepared product is thus obtained.

[0048] The method of the present invention includes the method steps described above, for example, in the order stated. The order of method steps M1 to M3 may be changed as needed. Method step M4 follows method steps M1 to M3. The method according to the present invention optionally includes additional method steps that may be performed before, during, or after method steps M1 to M4.

[0049] The mixing in step M4 can be performed using methods conventional to those skilled in the art. For example, component I, the at least one filler, and the at least one dispersing agent corresponding to formula (1) can be mixed in a suitable container using a stirrer.

[0050] The temperature in step M4 is preferably in the range of 5 to 60°C, and more preferably in the range of 10 to 50°C.

[0051] The present invention also relates to a kit of parts for providing a polyurethane-based thermally conductive adhesive formulation, comprising part 1 and part 2, wherein: Part 1 contains 1-1) At least one polyol; 1-2) At least one type of filler; 1-3) At least one dispersing agent corresponding to formula (1); and Part 2 includes 2-1) At least one component selected from isocyanates and polyurethane prepolymers; 2-2) At least one type of filler; 2-3) At least one dispersant corresponding to formula (1).

[0052] Partial kits are sometimes referred to in the prior art as multi-component formulations or multi-component systems, such as 2K formulations.

[0053] The term polyurethane is known to those skilled in the art and refers to a product obtained by reacting at least one isocyanate with at least one polyol (both as described above). Besides polyurethane, other chemical groups may also be formed in the reaction, such as urea diketone, carbodiimide, isocyanurate, allophane, biuret, urea group, and / or urea ketimide. In the context of this invention, the term polyurethane therefore also includes the reaction product formed from the polyol and isocyanate, which may additionally contain the aforementioned groups.

[0054] Polyurethane-based thermally conductive adhesive formulations can be obtained by mixing parts 1 and 2. Mixing can be carried out at room temperature and can be performed using standard methods. Individual components correspond to those described above. The amounts of the individual components in parts 1 and 2 are preferably selected such that, after mixing, they are present in the amounts described above for the preparations of the present invention. Parts 1 and 2 are preferably provided in a ratio such that the NCO index of the mixture obtained from parts 1 and 2 is in the range of 90 to 200%, preferably in the range of 95 to 175%, and even more preferably in the range of 97 to 159%. The term NCO index is known to those skilled in the art, and it describes the molar amount of all NCO groups present in part 2 relative to all isocyanate reactive groups (e.g., hydroxyl groups) present in part 1. At an NCO index of 100%, the number of NCO groups in part 2 is exactly the same as the number of all isocyanate reactive groups present in part 1; an NCO index > 100% indicates an excess of NCO groups, and an NCO index < 100% indicates that they are present in substoichiometry. If to be used, the optional catalyst described below is preferably added to section 1.

[0055] The proportions of individual components in the adhesive formulation correspond to those proportions in the preparation of the present invention, wherein they are reduced accordingly by the proportions added to the adhesive formulation (components not yet present in the preparation).

[0056] The present invention also relates to a polyurethane-based thermally conductive adhesive formulation comprising (or consisting of) the following: P1) At least one polyol; P2) At least one filler, preferably selected from alumina, aluminum hydroxide and aluminum hydroxide, wherein the adhesive formulation contains the at least one filler in an amount preferably 50 to 99% by weight, more preferably 70 to 95% by weight, and even more preferably 80 to 90% by weight, based on the total mass of the adhesive formulation; P3) At least one dispersant corresponding to formula (1); P4) At least one component selected from isocyanates and polyurethane prepolymers; and P5) At least one catalyst that is optionally present.

[0057] Polyurethane-based thermally conductive adhesive formulations can be obtained by mixing the aforementioned P1 to P4 and optionally P5.

[0058] The optional at least one catalyst facilitates the reaction of the at least one polyol and the at least one component I. Suitable catalysts are known to those skilled in the art. Preferred catalysts are selected from gel catalysts that catalyze the polyurethane reaction between isocyanates and polyols. These can be selected from the class of amine catalysts, such as triethylamine, dimethylcyclohexylamine, tetramethylethylenediamine, tetramethylhexanediamine, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, triethylenediamine, dimethylpiperazine, 1,2-dimethylimidazolium, N-ethylmorpholine, tris(dimethylaminopropyl)hexahydro-1,3,5-triazine, dimethylaminoethanol, dimethylaminoethoxyethanol, tetramethylguanidine, and 1,8-diazabicyclo[5.4.0]undec-7-ene. Furthermore, amine catalysts can be selected from the class of so-called emission-free catalysts, characterized by having a catalytically active nitrogen atom and an NCO reactive group, such as an OH group. Suitable emission-free amine catalysts are, for example, sold by Evonik under the Dabco NE product line. Furthermore, the catalyst can be selected from the category of metal catalysts, such as catalysts based on tin, zinc, bismuth, iron, copper, or zirconium. Metal catalysts can be used, for example, in the form of salts, or as catalysts for organic modification, such as tin laurylate, tin octoate, tin neodecanoate, or bismuth neodecanoate.

[0059] The present invention also relates to a thermally conductive adhesive formulation based on a silyl-modified polymer, comprising (or consisting of) the following: S1) At least one silane-modified polymer; S2) At least one filler, preferably selected from alumina, aluminum hydroxide and aluminum hydroxide, wherein the adhesive formulation contains the at least one filler in an amount preferably 50 to 99% by weight, more preferably 70 to 95% by weight, even more preferably 80 to 90% by weight, based on the total mass of the adhesive formulation; S3) At least one dispersing agent corresponding to formula (1); S4) At least one plasticizer may be present; S5) At least one adhesive accelerator may be present; S6) At least one desiccant that may be present; and S7) At least one catalyst for crosslinking silyl-modified polyethers, which may be present by choice.

[0060] Thermally conductive adhesive formulations based on silyl-modified polymers contain at least one plasticizer. Plasticizers are known to those skilled in the art. The at least one plasticizer can be used to adjust the viscosity of the formulation and, in addition, can affect the mechanical properties of the cured adhesive layer, such as tensile strength or elongation. Suitable plasticizers can be, for example, from the group consisting of: phthalates, such as dibutyl phthalate, diisononyl phthalate (DINP), di-2-ethylhexyl phthalate and diisodecyl phthalate (DIDP); terephthalates, such as bis(2-ethylhexyl) benzoate; phthalate-free plasticizers, such as diisononyl cyclohexane-1,2-dicarboxylate (DINCH); aliphatic carboxylic acid esters, such as dioctyl adipate, dioctyl sebacate and acetyl tributyl citrate; unsaturated fatty acid esters, such as butyl oleate; phenyl alkyl sulfonates; phosphate compounds, such as tricresyl phosphate or tributyl phosphate; chlorinated paraffins; hydrocarbon oils; and epoxidative plasticizers, such as epoxidized soybean oil. In addition, the plasticizer may be selected from polymer plasticizers, such as vinyl polymers, esters of polyalkylene glycols and polyester-based plasticizers, preferably based on diacids and diols.

[0061] Preferably, the thermally conductive adhesive formulation based on the silyl-modified polymer contains the at least one plasticizer in an amount of 5 to 100% by weight, more preferably 10 to 75% by weight, and even more preferably 15 to 50% by weight, based on the total mass of the thermally conductive adhesive formulation based on the silyl-modified polymer.

[0062] Optionally, the thermally conductive adhesive formulation based on silane-modified polymers includes at least one adhesion promoter. The adhesion promoter is known to those skilled in the art and is preferably selected from silane coupling agents, such as amino-containing silanes, such as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, N-β-aminoethyl-γ-aminopropyltriethoxysilane, and γ-ureidopropyltrimethoxysilane, and isocyanate-containing silanes, such as γ-isocyanopropyltrimethoxysilane. Silanes containing mercaptopropyltriethoxysilane, α-isocyanomethyltrimethoxysilane and α-isocyanomethyldimethoxymethylsilane, silanes containing thiol groups, such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane, silanes containing epoxy groups, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropylmethyldimethoxysilane, and carboxylsilanes, such as β-carboxylethyltriethoxysilane, unsaturated silanes with vinyl groups, and halogen-modified silanes.

[0063] Preferably, the thermally conductive adhesive formulation based on the silyl-modified polymer contains the at least one optional adhesion promoter in an amount of 0.05 to 20% by weight, more preferably 0.1 to 15% by weight, and even more preferably 0.5 to 10% by weight, based on the total mass of the thermally conductive adhesive formulation based on the silyl-modified polymer.

[0064] Optionally, the thermally conductive adhesive formulation based on silyl-modified polymers includes at least one desiccant. Desiccants are known to those skilled in the art. The at least one optional desiccant is preferably selected from powdered desiccants, particularly zeolites, molecular sieves, silica gel, or activated alumina, and trialkoxysilanes, particularly vinyltrialkoxysilanes, such as vinyltrimethoxysilane and vinyltriethoxysilane.

[0065] Preferably, the thermally conductive adhesive formulation based on the silyl-modified polymer contains the at least one optional desiccant in an amount of 0.05 to 20% by weight, more preferably 0.1 to 15% by weight, and even more preferably 0.5 to 10% by weight, based on the total mass of the thermally conductive adhesive formulation based on the silyl-modified polymer.

[0066] Optionally, the thermally conductive adhesive formulation based on the silyl-modified polymer includes at least one catalyst for crosslinking the silyl-modified polymer. Such catalysts are known to those skilled in the art. The optional catalyst for the at least one crosslinking silyl-modified polyether is preferably selected from amine catalysts, particularly 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene and 1,1,3,3-tetramethylguanidine; metal catalysts, particularly those based on bismuth, such as bismuth neodecanoate; those based on tin, such as dibutyltin dilaurate, dibutyltin dimaleate, dibutyltin dioctanoate, bis(2-ethylhexanoate)dibutyltin, dibutyltin diacetate, dibutyltin oxide and dioctyltin dilaurate; those based on titanium, such as tetrabutyl titanate, tetrapropyl titanate and tetra(acetylacetonyl)titanium; those based on zinc, such as zinc acetate or zinc ricinoleate; those based on aluminum and zirconium; organophosphates; organosulfonic acids and inorganic acids.

[0067] Preferably, the thermally conductive adhesive formulation based on silyl-modified polyether contains at least one optional catalyst for crosslinking the silyl-modified polyether, in an amount of 0.02 to 5% by weight, more preferably 0.05 to 3% by weight, and even more preferably 0.1 to 2% by weight, based on the total mass of the thermally conductive adhesive formulation based on the silyl-modified polymer.

[0068] The present invention also relates to a structure comprising (or consisting of): at least one battery cell (1), an adhesive layer (2) and a heat sink (3), characterized in that the adhesive layer (2) is produced by applying an adhesive formulation of the present invention, particularly a thermally conductive adhesive formulation based on a silyl-modified polymer or a thermally conductive adhesive formulation based on polyurethane, between the at least one battery cell (1) and the heat sink (3).

[0069] A battery cell is the basic functional unit of a battery and consists of an array of electrodes, including active materials, an electrolyte, a container, connectors, and typically separators. Generally, the structure of this invention comprises multiple battery cells forming a battery. The at least one or all battery cells are preferably designed such that they (in the case of all battery cells arranged side-by-side) can be mounted onto a heat sink.

[0070] The preferred radiator is a cooling plate. Such cooling plates are known to those skilled in the art. The radiator can be actively heated or cooled and is equipped with suitable devices.

[0071] The adhesive layer is preferably designed to cover the entire contact surface between the heat sink and the at least one battery cell. This ensures optimal possible heat dissipation from the at least one battery cell.

[0072] Another part of the present invention is a method for producing the structure of the present invention, comprising the following method steps: QA) Provide heat sinks; QB) provides at least one battery cell; and QC) Apply the adhesive formulation of the present invention, more particularly a thermally conductive adhesive formulation based on a silyl-modified polymer or a thermally conductive adhesive formulation based on polyurethane, between the heat sink and the at least one battery cell. The structure is thus obtained.

[0073] The method of the present invention includes the above-described method steps, preferably in the order stated. Method steps QA and QB may also be performed in a different order. The method according to the present invention optionally includes additional method steps that may be performed before, during, or after method steps QA to QC.

[0074] Optionally, the method of the present invention is supplemented by method step QD, which is performed after method step QC: QD) Curing of the adhesive layer.

[0075] Curing can be carried out using conventional methods. For example, the structure of the present invention can be exposed to elevated temperatures, such as in an oven. Curing, especially at elevated temperatures, also allows evaporable portions to be removed from the adhesive layer.

[0076] The present invention is further illustrated by reference to the following embodiments, which do not limit the subject matter of the invention. Detailed Implementation

[0077] Example Unless otherwise stated, commercial products are used in accordance with the technical information sheet available at the time of filing of this application.

[0078] Material Voranol CP 3322: Polyether triol, OH value = 56 mg KOH / g, from Dow Suprasec 6506: Polymer MDI, from Huntsman Martinal TM-3810: Powdered alumina with a bimodal particle size distribution (5 µm / 75 µm), from Huber. MS Polymer SAX 530: Methoxysilyl-terminated polyether from Kaneka Dispersant 1: a dispersing agent corresponding to formula (1), wherein R 1 = n-octyl, m = 11, n = 3 and R 2 = H.

[0079] Dispersant 2: The dispersing agent corresponding to formula (1), wherein R 1 = n-octyl, m = 11, n = 3 and R 2 = (OH)2-P(O)-, X 1 = X 2 = H, Y 1 = H and Y 2 = Phenyl, or Y 1 = Phenyl and Y 2 = H.

[0080] Polycat SA 2 LE: Polyurethane catalyst, from Evonik MS Polymer SAX 015: Reactive plasticizer, from Kaneka Dynasylan VTMO: Vinyltrimethoxysilane, from Evonik (desiccant) Dynasylan DAMO: 2-aminoethyl-3-aminopropyltrimethoxysilane, from Evonik (adhesion accelerator). Kosmos T 12: A dibutyltin laurylate-based catalyst from Evonik (a catalyst for crosslinking silyl-modified polyethers). Dispersion experiment All dispersion experiments were performed using a SpeedMixer (model DAC 400.1 FVZ, from Hauschild). For this purpose, all components were weighed into 25 ml plastic beakers and homogenized at 2750 rpm for 1 minute. The visual appearance of the filled system was then evaluated. Viscosity profiles of the samples were determined by shear rate-viscosity plots. These were performed using a plate-to-plate geometry rheometer (model MCR 702, from Anton-Paar). All viscosity measurements were taken at 25°C and within 1–10 s. -1 It is carried out within the range of shear rates.

[0081] Example 1 -- Dispersion Experiment in Polyurethane System To test the effectiveness of the dispersing additive of the present invention in polyurethane-based systems, dispersion experiments were conducted in both the polyol and isocyanate components. Tables 1 and 2 provide an overview of the various experimental compositions. In all cases, the samples were homogenized and evaluated according to the methods described above. The optical appearance of the samples and their performance at 0.1 s⁻¹ are also discussed. -1 The viscosity at the shear rate is also recorded in the table. Figure 1 and Figure 2 Additionally, a curve showing the viscosity of the sample as a function of shear rate is displayed.

[0082] Table 1: Overview of Dispersion Experiments in Polyols

[0083] Table 2: Overview of dispersion experiments in isocyanates

[0084] These experiments clearly demonstrate that the preparations of the present invention exhibit good stability. Therefore, in all cases, a significant reduction in viscosity was observed in the preparations of the present invention (Experiments #2, #3, #5, and #6) compared to the comparative formulations (Experiments #1 and #4). Furthermore, all preparations of the present invention exhibit a significantly improved optical appearance.

[0085] Example 2 -- Dispersion experiment in methoxysilyl-terminated polyethers Preparations of polyether systems with silyl-modified compounds were also tested. Table 3 provides an overview of the composition of these experiments. The samples were homogenized and evaluated again according to the methods described above. The optical appearance of the samples and their performance at 0.1 s⁻¹ are also discussed. -1 The viscosity at the shear rate is also recorded in Table 3. The viscosity curves of the samples as a function of shear rate are shown below. Figure 3 As shown in the image.

[0086] These experiments clearly demonstrate the superior stability of the preparations of the present invention (Experiments #8 and #9) compared to the comparative formulation (Experiment #7). Therefore, the preparations of the present invention exhibit a significant reduction in viscosity compared to the comparative formulation. Furthermore, the preparations of the present invention possess a significantly better optical appearance than those in the comparative experiments.

[0087] Table 3: Overview of dispersion experiments in MS Polymer SAX 530

[0088] Example 3 -- Preparation of a highly filled, polyurethane-based thermally conductive adhesive In addition to the dispersion experiments of the polyurethane system described in Example 1, polyurethane-based adhesive formulations were also prepared to further demonstrate the effectiveness of the invention. Table 4 provides an overview of the composition of these experiments.

[0089] Table 4: Overview of PU-based adhesive preparations

[0090] For these experiments, components A and B were first dispersed separately on a SpeedMixer according to the procedure described above. The two filler components were then mixed at the ratios described in Table 4 and homogenized again in a SpeedMixer at 2750 rpm for 1 minute. The resulting adhesive formulation was spread onto a metal plate (approximately 1 cm thick) and cured in an oven at 80°C for 5 minutes. In all cases, solid, well-cured adhesive formulations were obtained. The adhesive formulations of the present invention (Experiments #11 and #12) showed no change in curing performance. However, it is noteworthy that the adhesive formulations of the present invention can be spread significantly more easily on metal plates, producing a uniform, smooth, and defect-free adhesive layer in these cases. In the case of the contrast coating, the formulation was difficult to apply to the plate due to its high viscosity, resulting in an uneven layer with numerous imperfections and defects. Such unevenness leads to undesirable thermal bridging, which in turn reduces heat dissipation from the battery cell. The consequence can be a shortened battery cell lifespan.

[0091] Example 4 – Preparation of a highly filled thermally conductive adhesive derived from silyl-terminated polyether In addition, adhesive formulations based on silyl-terminated polyethers (silyl-modified polymers) were prepared to further demonstrate the effectiveness of the dispersing additives of the present invention. Table 5 provides an overview of these experimental compositions.

[0092] Table 5: Overview of adhesive formulations based on silyl-terminated polyethers

[0093] For these experiments, all components were dispersed using SpeedMixer according to the procedure described above. The resulting adhesive formulation was spread onto a metal plate (approximately 1 cm thick) and then cured overnight at room temperature. In all cases, a solid, well-cured adhesive layer was obtained. The adhesive formulations of the present invention (Experiments #14 and #15) showed no change in curing properties. However, it is noteworthy that the adhesive formulations of the present invention can be spread significantly more easily onto metal plates, producing a uniform, smooth, and defect-free adhesive layer in these cases. In the case of the comparative coating, the formulation was difficult to apply to the plate due to its high viscosity, resulting in an uneven coating with numerous blemishes and defects. Such unevenness leads to undesirable thermal bridging, which in turn reduces heat dissipation from the battery cell. The consequence can be a shortened battery cell lifespan.

Claims

1. A preparation for providing a thermally conductive adhesive formulation, comprising: I) At least one component, wherein the at least one component is selected from isocyanates and polymers; II) At least one filler; III) At least one dispersant corresponding to formula (1) R 1 -A m -B n -R 2 (1) in m is an integer in the range of 1 to 45, preferably 1 to 25; n is an integer in the range of 0 to 20, preferably 1 to 20; R 1 It is a monovalent aliphatic saturated or unsaturated hydrocarbon group having 1 to 39, preferably 3 to 39, more preferably 7 to 21, and most preferably 8 to 17 carbon atoms; R 2 Selected from -OH, -OR 3 、(R 4 O)2P(O)- and the form R 1 -A m -B n - group, in R 3 It is an alkyl group. Each R 4 Independently selected from cations, H, monovalent aliphatic saturated or unsaturated hydrocarbon groups having 1 to 39 carbon atoms, preferably 3 to 39, more preferably 7 to 22, and most preferably 9 to 18 carbon atoms, and in the form of R. 1 -A m -B n - group; Each A is an independent unit of a group of formula (1A): (1A)， Where X 1 and X 2 Selected from hydrogen and methyl, under the condition X 1 and X 2 At least one of them is hydrogen; and Each B is an independent unit of a group of formula (1B): (1B)， Where Y 1 and Y 2 Selected from hydrogen and phenyl, under the condition that Y 1 and Y 2 One of them is hydrogen and the other is phenyl.

2. The preparation according to claim 1, characterized in that... m is selected from the range of 3 to 20, preferably from the range of 5 to 15.

3. The preparation according to any one of claims 1 or 2, characterized in that... n is selected from the range of 2 to 15, preferably from the range of 3 to 10.

4. The preparation according to any one of the preceding claims, characterized in that... R 1 It is a C7-C17 alkyl group.

5. The preparation according to any one of the preceding claims, characterized in that... Based on the total mass of the preparation, the preparation contains 0.1 to 10.0% by weight, preferably 0.5 to 5.0% by weight, more preferably 1.0 to 3.0% by weight of the at least one dispersant corresponding to formula (1).

6. The preparation according to any one of the preceding claims, characterized in that... The at least one polymer is selected from polyols, polyethers, polyurethane prepolymers, and silyl-modified polymers.

7. The preparation according to any one of the preceding claims, characterized in that... The at least one filler is selected from alumina, aluminum hydroxide and aluminum hydroxyalumina.

8. The preparation according to any one of the preceding claims, characterized in that... Based on the total mass of the prepared article, the prepared article contains 50 to 99% by weight, preferably 70 to 95% by weight, more preferably 80 to 90% by weight of the at least one filler.

9. The use of the dispersant corresponding to formula (1) to improve the rheological properties of thermally conductive adhesive formulations, particularly to reduce viscosity and / or improve the stability of thermally conductive adhesive formulations.

10. A method for producing the preparation according to any one of claims 1 to 8, comprising the following method steps: M1) provides at least one component selected from isocyanates and polymers; M2) provides at least one type of filler; M3) provides at least one dispersing agent corresponding to formula (1); and M4) Mix the at least one component, the at least one filler, and the at least one dispersant corresponding to formula (1); This allows the prepared product to be obtained.

11. A partial kit for providing a polyurethane-based thermally conductive adhesive formulation, comprising part 1 and part 2, wherein: Part 1 contains 1-1) At least one polyol; 1-2) At least one type of filler; 1-3) At least one dispersing agent corresponding to formula (1); and Part 2 includes 2-1) At least one component selected from isocyanates and polyurethane prepolymers; 2-2) At least one type of filler; 2-3) At least one dispersant corresponding to formula (1).

12. A polyurethane-based thermally conductive adhesive formulation comprising... P1) At least one polyol; P2) At least one filler, preferably selected from alumina, aluminum hydroxide and aluminum hydroxide, wherein the adhesive formulation contains, based on the total mass of the adhesive formulation, preferably 50 to 99% by weight, more preferably 70 to 95% by weight, and even more preferably 80 to 90% by weight of the at least one filler; P3) At least one dispersant corresponding to formula (1); P4) At least one component selected from isocyanates and polyurethane prepolymers; and P5) At least one catalyst that is optionally present.

13. A thermally conductive adhesive formulation based on a silyl-modified polymer, comprising... S1) At least one silane-modified polymer; S2) At least one filler, preferably selected from alumina, aluminum hydroxide and aluminum hydroxide, wherein the adhesive formulation contains, based on the total mass of the adhesive formulation, preferably 50 to 99% by weight, more preferably 70 to 95% by weight, and even more preferably 80 to 90% by weight of the at least one filler. S3) At least one dispersing agent corresponding to formula (1); S4) At least one plasticizer may be present; S5) At least one adhesive accelerator may be present; S6) At least one desiccant that may be present; and S7) At least one catalyst for crosslinking silyl-modified polymers, which may be present by choice.

14. A structure comprising at least one battery cell (1), an adhesive layer (2), and a heat sink (3), characterized in that The adhesive layer (2) has been produced by applying an adhesive formulation according to any one of claims 12 or 13 between the at least one battery cell (1) and the heat sink (3).

15. A method for producing the structure according to claim 14, comprising the following method steps: QA) Provide heat sinks; QB) provides at least one battery cell; as well as QC) Apply the adhesive formulation according to any one of claims 12 or 13 between the heat sink and the at least one battery cell; This allows the obtained structure to be achieved.

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