Two-component thermally conductive composition

Abstract

The invention relates to a two-component thermally conductive composition comprising:-a component A comprising: o at least one polyol P having a functionality of at least 4, and o at least one thermally conductive filler; and-a component B comprising: o at least one polyisocyanate, and o at least one thermally conductive filler; wherein the at least one thermally conductive filler in each of components A and B is selected from the group consisting of metal silicates, metal oxides, metal hydroxides, metal and metalloid nitrides, metal and metalloid carbides, metal fillers, graphite and mixtures thereof. The invention also relates to the use of the composition according to the invention. Furthermore, the invention relates to a method for bonding substrates implementing a composition according to the invention. Finally, the invention relates to an article comprising a composition according to the invention.

Description

TECHNICAL FIELD

[0001] The present invention relates to a two-component heat-conductive composition and uses thereof, a process for bonding substrates and an article. BACKGROUND

[0002] Two-component polyurethane-type compositions are widely used as adhesives for manufacturing various assemblies. These two-component compositions comprise:

[0003] - an -NCO component comprising chemical entities carrying isocyanate (i.e. -NCO) groups, and

[0004] - an -OH component comprising chemical entities carrying hydroxyl (i.e. -OH) groups.

[0005] After mixing the two components, according to a reaction known as cross-linking, the isocyanate groups of the -NCO component react with the hydroxyl groups of the -OH component to form a polyurethane existing in the form of a three-dimensional network comprising urethane groups, thus providing cohesion of the adhesive between the substrates of the assembly.

[0006] Some applications, in particular assemblies intended for manufacturing batteries, require the composition to have specific properties, in particular in terms of thermal conductivity. Indeed, the recharging of a battery is usually accompanied by an increase in temperature, it is important to limit said increase as much as possible, which can degrade certain electronic circuits or even shorten the life of the battery. It is therefore important that the composition has a sufficient thermal conductivity to overcome these problems.

[0007] On an industrial scale, in particular for battery assemblies, the assembly is manufactured on an assembly line. Usually, one / robot applies the composition on a substrate, then another one / robot brings the composition into contact with another substrate and cures the composition, then the assembly is stored outside the assembly line. Thus, a long time can elapse after the composition is applied on the first substrate and before it is brought into contact with another substrate.

[0008] Therefore, there is a need to provide a heat-conductive composition having a long open time (time between the beginning of the mixing of the two components of the composition and the beginning of the curing of the composition).

[0009] However, shortly after the end of the open time, the composition should be sufficiently cured so as to remove the assembly of the assembly line and store it elsewhere. The additional time needed to comfortably manipulate the assembly at the end of the open time without destroying it is called the set time interval.

[0010] Therefore, there is a need to provide a heat-conductive composition having a short set time interval.

[0011] Furthermore, there is a need for a heat conducting composition which can remain stable during storage even at elevated temperatures such as 50 °C and / or even when the composition comprises a low diisocyanate monomer content (e.g. diisocyanates having a molar mass of less than 300 g / mol). The latter is advantageous since diisocyanate monomers are considered to be harmful to health.

[0012] It has now been found that one or more of these needs can be solved by the following composition. SUMMARY

[0013] The present invention relates to a two-component heat conducting composition comprising:

[0014] - Component A comprising:

[0015] o at least one polyol P having a functionality of at least 4, and

[0016] o at least one heat conducting filler; and

[0017] - Component B comprising:

[0018] o at least one polyisocyanate, and

[0019] o at least one heat conducting filler;

[0020] wherein the at least one heat conducting filler in each of components A and B is selected from the group consisting of metal silicates, metal oxides, metal hydroxides, metal and metalloid nitrides, metal and metalloid carbides, metallic fillers, graphite and mixtures thereof.

[0021] The present invention also relates to the use of the composition according to the present invention as an adhesive.

[0022] Furthermore, the present invention relates to a process for bonding substrates comprising the following steps:

[0023] - applying the composition according to the present invention on at least one surface of a substrate, and then

[0024] - contacting the substrates.

[0025] Finally, the present invention relates to an article comprising at least two substrates bonded by the composition according to the present invention.

[0026] The present invention allows to solve the above-mentioned needs. In particular, the composition according to the present invention surprisingly has a long open time and a short setting time while being stable after storage at elevated temperatures (e.g. 50 °C) even when its diisocyanate monomer content is low. SUMMARY

[0027] Composition

[0028] Polyol P

[0029] Component A contains at least one polyol P with a functionality of at least 4, i.e., an organic compound having at least 4 hydroxyl (-OH) groups.

[0030] Advantageously, the functionality of polyol P is 4 to 10, preferably 4 to 6, and especially equal to 4 (tetraol).

[0031] The at least one polyol P can be selected from polyester polyols, polyether polyols, and mixtures thereof, preferably from polyether polyols.

[0032] "Polyester polyol" refers to a polyol containing at least two ester groups, and it may also contain other functional groups.

[0033] As an example of a polyester polyol, one may mention polyester polyols obtained by esterification of a polyol having a functionality of at least 4, particularly equal to 4 (e.g., pentaerythritol or pentane-1,2,4,5-tetraol, preferably pentaerythritol). Advantageously, esterification is carried out with lactones, cyclic diesters (e.g., glycolide, lactide) and / or hydroxycarboxylic acids (i.e., carboxylic acids containing one or more hydroxyl groups), preferably with lactones such as caprolactone or γ-butyrolactone, more preferably caprolactone.

[0034] According to one implementation scheme, the polyester polyol is polycaprolactone tetraol obtained from pentaerythritol.

[0035] "Polyether polyol" refers to a polyol containing at least two ether groups, and it may also contain other functional groups, such as tertiary amines.

[0036] The polyether polyol can be initiated by a polyol or an amine. Specifically, it can be initiated by a polyol containing at least four hydroxyl groups, particularly four hydroxyl groups, or by an amine containing at least four hydrogen atoms (each forming a hydroxyl or an amino group, preferably a portion of an amino group), particularly four hydrogen atoms. Preferably, the polyether polyol is amine-initiated; more preferably, it is initiated by an amine containing at least two primary amine groups, particularly a diamine amine containing two primary amine groups.

[0037] For example, the polyether polyol may be initiated with pentaerythritol, sorbitol and / or pentane-1,2,4,5-tetraol, preferably pentaerythritol polyol.

[0038] For example, polyether polyols can be initiated by ethylenediamine, 1,3-diaminopropane, 1,3-diaminobutane, 1,4-diaminobutane, N,N-bis(3-aminopropyl)methylamine, neopentyldiamine, 4,4'-methylenebis(cyclohexylamine) and / or diethylenetriamine, preferably ethylenediamine, 1,3-diaminopropane, 1,3-diaminobutane and / or 1,4-diaminobutane, more preferably ethylenediamine.

[0039] Advantageously, the polyether polyol is ethoxylated, propoxylated, and / or butoxylated (random or block), preferably ethoxylated and / or propoxylated, more preferably propoxylated.

[0040] According to a preferred embodiment, the polyether polyol is an ethoxylated and / or propoxylated diamine, said diamine comprising two primary amine groups. Preferably, the diamine is ethylenediamine, 1,3-diaminopropane, 1,3-diaminobutane, or 1,4-diaminobutane, more preferably ethylenediamine. In particular, the polyether polyol is propoxylated ethylenediamine.

[0041] The OH value of polyol P can be between 200 and 2500 mg KOH / g, preferably between 250 and 1250 mg KOH / g, and more preferably between 300 and 700 mg KOH / g.

[0042] In the context of this invention, the range of values ​​should be understood to include extreme values. For example, the range "between 0% and 25%" specifically includes the values ​​0% and 25%.

[0043] The OH value can be determined according to ISO 14900:2017.

[0044] Advantageously, the number average molecular weight of polyol P is between 200 g / mol and 2000 g / mol, preferably between 300 g / mol and 1100 g / mol, and more preferably between 350 g / mol and 700 g / mol.

[0045] The number-average molecular weight (Mn) of polyol P can be determined by the following calculation: Mn = (f OH 56100) / I OH Mn is expressed in g / mol, f OH It is the functionality of polyol P, and I OH It is the OH value of polyol P, expressed in mg KOH / g.

[0046] The total content of the at least one polyol P in component A may be between 3% by weight and 15% by weight, preferably between 4% by weight and 12% by weight, relative to the total weight of component A.

[0047] Polyol P'

[0048] Component A may also contain at least one polyol P' different from polyol P. Specifically, the functionality (hydroxyl groups) of polyol P' is between 2 and 3, preferably 2.

[0049] The at least one polyol P' may be selected from polyester polyols, polyether polyols, polyene polyols, and mixtures thereof, preferably from polyether polyols.

[0050] Polyester polyols include those that can be obtained by reacting at least one polyol with at least one polycarboxylic acid or its esterification derivative, said esterification derivative being able to form an ester bond (e.g., its anhydride or acyl halide) upon reaction with a hydroxyl group.

[0051] The polycarboxylic acid may be selected from succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, 1,12-dodecanoic acid, 1,18-octadecanoic acid, fumaric acid or its dimer, maleic acid or its dimer, 1,4-cyclohexanedicarboxylic acid, isophthalic acid, phthalic acid, terephthalic acid, their ester derivatives, and mixtures thereof. Preferably, the polycarboxylic acid is selected from succinic acid, adipic acid, azelaic acid, sebacic acid, 1,12-dodecanoic acid, isophthalic acid, phthalic acid, terephthalic acid, their ester derivatives, and mixtures thereof.

[0052] The polyols can be selected from ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol (propylene glycol), 1,3-propanediol, trimethylolpropane, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 3-ethyl-2-methyl-1,5-pentanediol, 2-ethyl-3-propyl-1,5-pentanediol, 2,4-dimethyl-3-ethyl-1,5-pentanediol, 2-ethyl-4-methyl-3-propyl-1,5-pentanediol, 2,3-diethyl-4-methyl-1,5-pentanediol, 3-ethyl-2,2,4-trimethyl-1,5-pentanediol, and 2,2-dimethyl-4-ethyl-3-propyl-1,5-pentanediol. 2-Methyl-2-propyl-1,5-pentanediol, 2,4-dimethyl-3-ethyl-2-propyl-1,5-pentanediol, 2,3-dipropyl-4-ethyl-2-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,5-pentanediol, 2-butyl-2,3-diethyl-4-methyl-1,5-pentanediol, 2-butyl-2,4-diethyl-3-propyl-1,5-pentanediol, 3-butyl-2-propyl-1,5-pentanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-pentanediol, 2,2-dimethyl-1,5-pentanediol, 3,3-dimethyl-1,5-pentanediol, 2,3-dimethyl-1,5-pentanediol 2,2-Dimethyl-1,3-propanediol (neopentyl glycol), 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,3-propanediol, 2-benzyloxy-1,3-propanediol, 2,2-dibenzyl-1,3-propanediol, 2,2-dibutyl-1,3-propanediol, 2,2-diisobutyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,6-hexanediol, 2,5-dimethyl-1,6-hexanediol, 5-methyl-2-(1-methylethyl)-1,3-hexanediol, 1,4-dimethyl-1,4-butanediol, 1,5-hexanediol, 3-methyl-1 6-Hexanediol, 3-tert-butyl-1,6-hexanediol, 1,3-heptanediol, 1,2-octanediol, 1,3-octanediol, 2,2,7,7-tetramethyl-1,8-octanediol, 2-methyl-1,8-octanediol, 2,6-dimethyl-1,8-octanediol, 1,7-octanediol, 4,4,5,5-tetramethyl-3,6-dioxa-1,8-octanediol, 2,2,8,8-tetramethyl-1,9-nonanediol, 1,2-nonanediol, 2,8-dimethyl-1,9-nonanediol, 1,5-nonanediol, 2,9-dimethyl-2,9-dipropyl-1,10-decanediol, 2,9-dibutyl-2,9-dimethyl-1,10-decanediol, 2,9-dimethyl-2,9-dipropyl-1,10-Decanediol, 2,9-Diethyl-2,9-dimethyl-1,10-decanediol, 2,2,9,9-Tetramethyl-1,10-decanediol, 2-Nonyl-1,10-decanediol, 1,9-Decanediol, 2,2,6,6,10,10-Hexamethyl-4,8-dioxa-1,11-undecanediol, 2-Octyl-1,11-undecanediol, 2,10-Diethyl-2,10-dimethyl-1,11-undecanediol, 2,2,10,10-Tetramethyl-1,11-undecanediol, 1-Phenyl-1,11-undecanediol, 1,2-Undecanediol, 1,2-Dodecanediol, 2,11-Dodecanediol, 2,11-Diethyl-2,11- Dimethyl-1,12-dodecanediol, 2,11-dimethyl-2,11-dipropyl-1,12-dodecanediol, 2,11-dibutyl-2,11-dimethyl-1,12-dodecanediol, 2,2,11,11-tetramethyl-1,12-dodecanediol, 1,11-dodecanediol, 11-methyl-1,7-dodecanediol, 1,4-dodecanediol, 1,3-dodecanediol, 1,10-dodecanediol, 2,11-dimethyl-2,11-dodecanediol, 1,5-dodecanediol, 6,7-dodecanediol, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 1,4-cyclohexanediol, 1,4-cyclohexanediol, and mixtures thereof. Preferably, the polyol is selected from ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, trimethylolpropane, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, bisphenol A, 1,4-cyclohexanediol, 1,4-cyclohexanediol, and mixtures thereof.

[0053] Polyester polyols can also be obtained by polymerizing at least one hydroxycarboxylic acid, lactone, and / or cyclic diester (e.g., glycolide, lactide).

[0054] Examples of polyester polyols are castor oil (or ricinoleic acid triglyceride), polycarbonate diol, polycaprolactone, esters of adipic acid and hexanediol, esters of adipic acid, diethylene glycol and monoethylene glycol, esters of ethylene glycol and dodecanoic acid, and 3-methyl-1,5-pentanediol adipate.

[0055] According to the first embodiment, the polyether polyol may be a polyoxyalkylene (homopolymer or copolymer). The alkylene portion of the polyoxyalkylene may contain 1 to 4 carbon atoms, preferably 2 and / or 3 carbon atoms (i.e., polyethylene glycol, polypropylene glycol, or poly(ethylene glycol-propylene glycol)). In particular, the polyether polyol may be polypropylene glycol.

[0056] According to the second embodiment, the polyether polyol can be initiated by a polyol or an amine, that is, initiated by a diol or triol, particularly a diol, or by an amine containing 2 or 3 hydrogen atoms (each forming part of a hydroxyl or amino group), particularly 2 hydrogen atoms. Preferably, the polyether polyol is initiated by a polyol; more preferably, the polyether polyol is initiated by a diol. It should be understood that the portion from the diol or triol (used to initiate the polyether polyol) is not repeated twice (or more times) in the molecular structure of the polyether polyol.

[0057] The polyether polyol can be initiated by aliphatic polyols or polyols containing one or more aromatic rings, preferably polyols containing one or more aromatic rings.

[0058] For example, polyether polyols can be initiated by polyol initiators selected from trimethylolethane, trimethylolpropane, glycerol, triethanolamine, cyclohexanediol, 4,4'-isopropylidene diphenol, bis-(4-hydroxy-3,5-difluorophenyl)methane, 1,1-bis-(4-hydroxyphenyl)ethane, 2,2-bis-(4-hydroxy-3-methylphenyl)propane (CAS: 79-97-0), 2,2-bis-(4-hydroxy-3,5-dichlorophenyl)propane (CAS: 79-95-8), 2,2-bis(4-hydroxyphenyl)butane, 4,4'-methylenediphenol, 2,4'-methylenediphenol, and 2,2'-methylenediphenol. Preferably, the polyether polyol is initiated with 4,4'-isopropylidene diphenol, 1,1-bis-(4-hydroxyphenyl)ethane, 2,2-bis-(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 4,4'-methylenediphenol, 2,4'-methylenediphenol, or 2,2'-methylenediphenol, especially 4,4'-isopropylidene diphenol.

[0059] For example, the polyether polyol can be initiated by N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, 3-dimethylaminopropylamine, N-methyl-1,2-ethylenediamine or N-methyl-1,3-propanediamine, preferably N,N'-dimethylethylenediamine or N,N'-diethylethylenediamine.

[0060] Advantageously, the polyether polyol of the second embodiment is ethoxylated, propoxylated and / or butoxylated (random or block), preferably ethoxylated and / or propoxylated, more preferably propoxylated.

[0061] Specifically, the polyether polyol is an ethoxylated and / or propoxylated diol; said diol is a polyol initiator (different from propylene glycol and ethylene glycol). Advantageously, the diol is one of the diols disclosed above for use as polyol initiators. Preferably, the diol is 4,4'-isopropylidene diphenol, 1,1-bis-(4-hydroxyphenyl)ethane, 2,2-bis-(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 4,4'-methylenediphenol, 2,4'-methylenediphenol, or 2,2'-methylenediphenol, more preferably 4,4'-isopropylidene diphenol. Specifically, the polyether polyol is propoxylated 4,4'-isopropylidene diphenol.

[0062] According to a preferred embodiment, the at least one polyol P' comprises (or consists of) a mixture of (or is composed of) at least one polyether polyol according to the first embodiment and at least one polyether polyol according to the second embodiment. Preferably, the at least one polyol P' comprises (or is composed of) at least one polyether polyol selected from polyethylene glycol, polypropylene glycol and poly(ethylene glycol-propylene glycol) and at least one polyether polyol selected from ethoxylated and / or propoxylated diols.

[0063] "Polyene polyols" refer to polyols containing at least two carbon-carbon double bonds, and may also contain other functional groups.

[0064] Examples of polyene polyols include polyisoprene, polybutadiene, polypentadiene, butadiene-isoprene copolymers and / or isobutylene-isoprene copolymers, which are optionally hydrogenated or epoxidized.

[0065] The OH value of polyol P' can be between 20 and 700 mg KOH / g, preferably between 50 and 500 mg KOH / g.

[0066] The OH value can be determined according to ISO 14900:2017.

[0067] The number-average molecular weight of polyol P' can be between 200 g / mol and 5000 g / mol, preferably between 300 g / mol and 3000 g / mol.

[0068] The number-average molecular weight (Mn) of polyol P' can be determined by the following calculation: Mn = (f OH 56100) / I OH Mn is expressed in g / mol, f OH The functionality of polyol P' is given by I. OH The value is the OH value of polyol P, expressed in mg KOH / g.

[0069] When at least one polyol P' is present in component A, the total content of the at least one polyol P' in component A may be between 3% by weight and 15% by weight, preferably between 4% by weight and 12% by weight, relative to the total weight of component A.

[0070] Polyisocyanate

[0071] Component B contains at least one polyisocyanate (i.e., a compound having at least two isocyanate (-NCO) groups), preferably at least one polyisocyanate containing at least three isocyanate groups.

[0072] The at least one polyisocyanate may be monomeric and / or polymeric. For example, the at least one polyisocyanate may comprise monomeric isocyanurate and polymeric isocyanurate (i.e., containing at least two isocyanurate groups).

[0073] The at least one polyisocyanate may be selected from aliphatic polyisocyanates, aromatic polyisocyanates, and mixtures thereof, preferably from aliphatic polyisocyanates.

[0074] In the context of this invention, an aliphatic polyisocyanate is a polyisocyanate in which a nitrogen atom without a -NCO group is directly covalently bonded to a carbon atom that is part of an aromatic hydrocarbon ring. For example, m-phenylenedimethyl diisocyanate (m-XDI) is an aliphatic polyisocyanate according to the invention. Furthermore, aliphatic polyisocyanates do not contain carbamate groups. Therefore, an aromatic polyisocyanate is a polyisocyanate in which at least one nitrogen atom of a -NCO group is directly covalently bonded to a carbon atom that is part of an aromatic hydrocarbon ring.

[0075] Examples of aliphatic polyisocyanates include isophorone diisocyanate, dicyclohexylmethane 4,4'-diisocyanate, 1,4-cyclohexene diisocyanate, 1,2-cyclohexene diisocyanate, 2,4-diisocyanate-1-methylcyclohexane, 1,3-diisocyanate-2-methylcyclohexane, m-xylene diisocyanate, hydrogenated m-xylene diisocyanate, tetramethylxylene diisocyanate, 1,2-ethylene diisocyanate, 1,3-propylene diisocyanate, 1,4-butylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,7-heptamethylene diisocyanate, 1,8-octamethylene diisocyanate, their derivatives (e.g., biuret, isocyanurates and / or adducts with polyols, which are monomers and / or polymers), and mixtures thereof. Preferably, the aliphatic polyisocyanate is selected from isophorone diisocyanate, m-xylene diisocyanate, hydrogenated m-xylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, its derivatives (e.g., biuret, isocyanurate and / or adducts with polyols, which are monomers and / or polymers) and mixtures thereof, more preferably from 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, its derivatives (e.g., biuret, isocyanurate and / or adducts with polyols, which are monomers and / or polymers) and mixtures thereof.

[0076] Examples of aromatic polyisocyanates include toluene diisocyanate, diphenylmethane diisocyanate, diphenylpropane diisocyanate, naphthalene diisocyanate, phenylene diisocyanate, derivatives thereof (e.g., biuret, isocyanurate, and / or adducts with polyols, which are monomers and / or polymers), and mixtures thereof. Preferably, the aromatic polyisocyanate is selected from toluene diisocyanate, diphenylmethane diisocyanate, derivatives thereof (e.g., biuret, isocyanurate, and / or adducts with polyols, which are monomers and / or polymers), and mixtures thereof.

[0077] Preferably, the at least one polyisocyanate is selected from biuret, isocyanurate, adducts with polyols and mixtures thereof, more preferably from isocyanurate, wherein the at least one polyisocyanate is monomeric and / or polymeric.

[0078] According to a preferred embodiment, the at least one polyisocyanate is selected from 1,6-hexamethylene diisocyanate isocyanurate, isophorone diisocyanate isocyanurate, 1,5-pentamethylene diisocyanate isocyanurate, m-xylene diisocyanate isocyanurate, hydrogenated m-xylene diisocyanate isocyanurate, 1,6-hexamethylene diisocyanate biuret, adducts of m-xylene diisocyanate with glycerol, trimethylolpropane, or trimethylolethane, and mixtures thereof, preferably selected from 1,6-hexamethylene diisocyanate isocyanurate, isophorone diisocyanate isocyanurate, 1,5-pentamethylene diisocyanate isocyanurate, m-xylene diisocyanate isocyanurate, hydrogenated m-xylene diisocyanate isocyanurate, and mixtures thereof, particularly 1,6-hexamethylene diisocyanate isocyanurate. As mentioned above, the polyisocyanate may be monomeric and / or polymerized.

[0079] The total content of the at least one polyisocyanate in component B may be between 5% by weight and 25% by weight, preferably between 10% by weight and 20% by weight, relative to the total weight of component B.

[0080] Thermally conductive filler

[0081] The compositions according to the invention each contain at least one thermally conductive filler in components A and B. The thermally conductive filler is used to impart good thermal conductivity to the compositions according to the invention (advantageously between 1.0 and 3 W / mK).

[0082] The at least one thermally conductive filler in each of components A and B may be the same or different.

[0083] At least one of the thermally conductive fillers in the composition according to the invention may be a surface-treated thermally conductive filler. Preferably, at least one of the thermally conductive fillers in the composition is a surface-treated thermally conductive filler, and at least one of the thermally conductive fillers in the composition is an untreated thermally conductive filler.

[0084] Advantageously, the surface treatment is a hydrophobic surface treatment. The hydrophobic surface treatment provides hydrophobic groups on the surface of the thermally conductive filler. Hydrophobic groups are well known to those skilled in the art and include, for example, alkyl, aryl (e.g., phenyl), alkenyl, and halogen groups. Conversely, groups such as hydroxyl, aldehyde, carboxylic acid, ether, glycidyl ether, and amino are considered hydrophilic groups. Hydrophobic groups can be added by surface treatment with metal alkoxides (e.g., alkoxysilanes and / or titanium alkoxides) having hydrophobic groups directly bonded to metal atoms. For example, the surface treatment can be carried out with alkylalkoxysilanes, particularly alkyltrialkoxysilanes, such as alkyltrimethoxysilanes and / or alkyltriethoxysilanes. "Alkylalkoxysilane" refers to a silane containing at least one alkoxy group and at least one alkyl group bonded to a silicon atom. Preferably, the surface-treated thermally conductive filler does not have isocyanate-reactive groups, i.e., it does not react with isocyanate compounds.

[0085] The at least one thermally conductive filler (surface-treated or untreated) in each of components A and B is selected from metal silicates, metal oxides, metal hydroxides, metal nitrides and quasi-metal nitrides, metal carbides and quasi-metal carbides, metal fillers, graphite, and mixtures thereof, preferably selected from metal silicates, metal oxides, metal hydroxides, metal nitrides and quasi-metal nitrides, and mixtures thereof, more preferably selected from metal oxides, metal hydroxides, and mixtures thereof.

[0086] Examples of metal silicates are tin, indium, antimony, aluminum, titanium, iron, magnesium and / or zinc silicates, with aluminum silicates being preferred.

[0087] Examples of metal oxides are tin, indium, antimony, titanium, iron, zinc, magnesium and / or aluminum oxides, preferably zinc, magnesium and / or aluminum oxides, and more preferably aluminum oxide (i.e., Al2O3).

[0088] Examples of metal hydroxides are tin, indium, antimony, titanium, iron, zinc, magnesium and / or aluminum hydroxides, preferably magnesium and / or aluminum hydroxides, and more preferably aluminum hydroxide (i.e., Al(OH)3).

[0089] Examples of metallic and metalloid nitrides are tin, indium, antimony, titanium, iron, magnesium, zinc, silicon, aluminum and / or boron nitrides, with aluminum and / or boron nitrides being preferred.

[0090] Examples of metallic and near-metallic carbides are silicon and / or tungsten carbides.

[0091] Examples of metallic fillers are silver, copper, and / or aluminum.

[0092] Advantageously, the at least one thermally conductive filler (surface-treated or unsurface-treated) in each of components A and B is selected from aluminosilicates, alumina, aluminum hydroxide, aluminum nitride, boron nitride, zinc oxide, magnesium oxide, and mixtures thereof, more preferably from alumina, aluminum hydroxide, and mixtures thereof, particularly from mixtures of alumina and aluminum hydroxide.

[0093] According to one embodiment, the composition according to the invention comprises at least one surface-treated thermally conductive filler selected from metal hydroxides (especially aluminum hydroxide) and at least one untreated thermally conductive filler selected from metal oxides, metal hydroxides and mixtures thereof (especially aluminum oxide, aluminum hydroxide and mixtures thereof).

[0094] Advantageously, at least one of the thermally conductive fillers in each of components A and B is electrically insulating. "Electrically insulating" specifically refers to a conductivity of less than or equal to 0.1 S / m at 23°C, preferably less than or equal to 0.01 S / m at 23°C. The conductivity can be measured according to ISO 787-14 (2002) standard.

[0095] The average particle size of the thermally conductive filler can be between 0.1 μm and 60 μm, preferably between 5 μm and 50 μm.

[0096] The average particle size advantageously corresponds to particle size Dv50, which is the maximum size of the smallest particle by volume of 50%, and can be measured by laser diffraction on a MALVERN type device (e.g., according to ISO 13320).

[0097] Unless otherwise stated, the standards mentioned throughout this application are those that were in effect on the date of filing.

[0098] The total content of the at least one thermally conductive filler in component A relative to the total weight of component A may be between 55% by weight and 94% by weight, preferably between 65% by weight and 90% by weight, and more preferably between 75% by weight and 85% by weight.

[0099] The total content of the at least one thermally conductive filler in component B relative to the total weight of component B may be between 55% by weight and 94% by weight, preferably between 65% by weight and 90% by weight, and more preferably between 75% by weight and 85% by weight.

[0100] Relative to the total weight of each of components A and B, the total content of the at least one thermally conductive filler in each of components A and B may be between 55% by weight and 94% by weight, preferably between 65% by weight and 90% by weight, and more preferably between 75% by weight and 85% by weight.

[0101] Catalyst

[0102] Advantageously, component A contains a crosslinking catalyst.

[0103] The crosslinking catalyst can be selected from organometallic catalysts, tertiary amines, and mixtures thereof, preferably from organometallic catalysts.

[0104] The organometallic catalyst may be selected from metal alkoxides, metal carboxylates, metal coordination complexes having one or more organic ligands (e.g., acetylacetonates), and mixtures thereof. Preferably, the metal is bismuth, zinc, titanium, zirconium, and / or tin, more preferably bismuth and / or zinc.

[0105] For example, organometallic catalysts can be selected from:

[0106] - Bismuth carboxylate (bismuth acetate, bismuth neodecanoate, etc.), especially bismuth neodecanoate.

[0107] - Zinc carboxylate (zinc acetate, zinc neodecanoate, etc.), especially zinc neodecanoate.

[0108] - Organic derivatives of titanium, such as titanium acetylacetonate, tetrapropoxy titanium, tetraisopropyl titanate, tetrabutoxy titanium, and tetraethoxy titanium.

[0109] - Organic derivatives of zirconium, such as zirconium acetylacetonate, zirconium tetrapropoxy, zirconium tetraisopropyl, zirconium tetrabutoxy, and zirconium tetraethoxy.

[0110] - Tin-based catalysts, such as compounds derived from dioctyltin or dibutyltin (especially dibutyltin dilaurate or dioctyltin), and

[0111] - Its mixture.

[0112] Preferably, the organometallic catalyst is selected from:

[0113] - Bismuth carboxylate, especially bismuth neodecanoate,

[0114] - Zinc carboxylate, especially zinc neodecanoate,

[0115] - Organic derivatives of titanium, such as titanium acetylacetonate, tetrapropoxy titanium, tetraisopropyl titanate, tetrabutoxy titanium, and tetraethoxy titanium.

[0116] - Organic derivatives of zirconium, such as zirconium acetylacetonate, zirconium tetrapropoxy, zirconium tetraisopropyl, zirconium tetrabutoxy, zirconium tetraethoxy, and

[0117] - Its mixture.

[0118] More preferably, the organometallic catalyst is selected from bismuth carboxylate, zinc carboxylate, and mixtures thereof, especially neodecanoate.

[0119] Examples of tertiary amines include triethylamine, tributylamine, N,N-dimethylcyclohexylamine, dimethylbenzylamine, N,N'-dimethylpiperazine, N,N,N,N-tetramethylpropane-1,3-diamine, bis(2-dimethylaminoethyl) ether, 2-dimethylaminoethyl-3-dimethylaminopropyl ether, N-methylmorpholine, N-ethylmorpholine, N-(methoxyethyl)morpholine, 2,2'-dimorpholine diethyl ether (DMDEE), bis(2,6-dimethylmorpholine ethyl) ether, bis(3,5-dimethylmorpholine ethyl) ether, N,N-dimethylaniline, N,N,N,N-tetramethylbutane-1,3-diamine, N,N,N,N-tetramethylpropane-1,3-diamine, N,N,N,N-tetramethylhexane-1,6-diamine, 1-methylimidazolium, and 2-methyl-1-ethyl Alkenyl imidazole, 1-allyl imidazole, 1-phenyl imidazole, 1,2,4,5-tetramethylimidazolium, pyrimidinazole, 4-(dimethylamino)pyridine, 4-pyrrolylpyridine, 4-morpholinopyridine, 4-methylpyridine, N-decyl-2-methylimidazolium, N-dodecyl-2-methylimidazolium, tris(dimethylaminopropyl)hexahydrotriazine, tetramethylguanidine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), quinine ring, bis(dimethylaminomethyl)phenol, 2-(2-dimethylaminoethoxy)ethanol, quinine cyclool, (hydroxymethyl)quinine ring, especially DABCO and / or DMDEE.

[0120] The crosslinking catalyst content in component A may be between 0.01 wt% and 0.2 wt% relative to the total weight of component A, preferably between 0.03 wt% and 0.15 wt%, and more preferably between 0.05 wt% and 0.11 wt%.

[0121] Further additives

[0122] The compositions according to the invention may further comprise one or more additives (in components A and / or B), particularly selected from plasticizers, solvents, rheology modifiers, pigments, adhesion promoters, hygroscopic agents, UV stabilizers (or antioxidants), dispersants, defoamers, and mixtures thereof, preferably selected from pigments, hygroscopic agents, dispersants, defoamers, and mixtures thereof.

[0123] Advantageously, the compositions according to the invention comprise a mixture of additives selected from pigments, humectants, dispersants and defoamers.

[0124] The total content of additives relative to the total weight of the composition according to the invention can be up to 10% by weight, preferably between 0.1% by weight and 5% by weight.

[0125] The plasticizer can be any plasticizer commonly used in the field of adhesive compositions.

[0126] For example, plasticizers may be selected from alkyl phthalates (e.g., diisodecyl phthalate, diisononyl phthalate, diisononyl hexahydrophthalate), esters of alkyl sulfonic acids and phenols (e.g., MESAMOLL® provided by LANXESS), pentaerythritol tetravalerate, diisononyl-1,2-cyclohexane dicarboxylate, 3,3'-methylenebis(oxymethylene)]bis[heptane], dioctyl carbonate, and mixtures thereof.

[0127] The plasticizer content may be up to 8% by weight, preferably up to 5% by weight, relative to the total weight of the composition according to the invention.

[0128] The compositions according to the invention may contain up to 5% by weight of a solvent relative to the total weight of the composition, preferably a solvent that evaporates at room temperature (about 23°C). The solvent may be, for example, selected from ethyl acetate, petroleum ether, C6-C23 hydrocarbons, and mixtures thereof. In the context of this invention, water and alcohols are not considered solvents.

[0129] The rheology modifier may be a self-thixotropic agent, for example selected from:

[0130] - PVC plastisols, specifically corresponding to suspensions of PVC in plasticizers miscible with PVC, obtained in situ by heating to a temperature ranging from 60°C to 80°C. These plastisols are particularly those described in the publication PolyurethaneSealants, Robert M. Evans, ISBN 087762-998-6.

[0131] - Pyrolytic silicon dioxide,

[0132] - Urea derivatives derived from diisocyanate monomers, preferably aromatic diisocyanate monomers such as methylene diphenyl diisocyanate (e.g., 4,4'-MDI) reacted with aliphatic primary amines such as butylamine.

[0133] - Waxes derived from castor oil, such as THIXCIN® R sold by ELEMENTIS.

[0134] - Amide waxes, preferably micronized amide waxes, such as Crayvallac® SLT sold by Arkema, and

[0135] - Its mixture.

[0136] If waxes are used, it is preferable to introduce them into component A.

[0137] The rheology modifier content may be up to 5% by weight, preferably up to 3% by weight, relative to the total weight of the composition according to the invention.

[0138] Pigments may be selected from organic pigments, inorganic pigments, and mixtures thereof. For example, pigments may be selected from phthalocyanine-based pigments (e.g., copper phthalocyanine, copper halide phthalocyanine, metal-free phthalocyanine), anthraquinone-based pigments (e.g., 1-methylamino-4-o-tolylaminoanthraquinone, 1,4-diisopropylaminoanthraquinone, 1,4-diaminoanthraquinone, 1,4-dibutylaminoanthraquinone, 1-amino-4-aniline-anthraquinone), quinacridone-based pigments, perylene-based pigments; indigo-based pigments, quinacridone-based pigments, titanium dioxide, carbon black, manganese ferrite, and mixtures thereof, particularly selected from anthraquinone-based pigments, such as 1,4-dibutylaminoanthraquinone.

[0139] The pigment content relative to the total weight of the composition according to the invention can be up to 1% by weight, preferably between 0.001% by weight and 0.5% by weight.

[0140] The adhesion promoter may be selected from aminoalkoxysilanes (e.g., (3-aminopropyl)trimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane), mercaptoalkoxysilanes, epoxyalkoxysilanes (e.g., (3-glycidyloxypropyl)trimethoxysilane), and mixtures thereof.

[0141] The adhesion promoter content may be up to 5% by weight, preferably up to 2% by weight, relative to the total weight of the composition according to the invention.

[0142] The hygroscopic agent can be selected from monoisocyanates, such as p-toluenesulfonyl isocyanate.

[0143] The desiccant content may be up to 3% by weight relative to the total weight of the composition according to the invention, preferably between 0.1% and 1.5% by weight.

[0144] UV stabilizers (or antioxidants) can be selected from benzotriazole, benzophenone, hindered phenols (e.g., ethylene bis(oxoethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], 2,2'-methylene bis(6-(tert-butyl)-4-methylphenol), 2,2'-methylene bis(6-(tert-butyl)-4-ethylphenol), 2,2'-methylene bis(4-methyl-6-cyclohexylphenol), 2,2'-methylene bis(4,6-di(tert-butyl)phenol), 4,4'-methylene bis(2,6-di(tert-butyl)phenol). Phenol, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6-di(tert-butyl)-4-methylphenol, hindered amines (e.g., bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate (CAS No.: 41556-26-7), methyl 1,2,2,6,6-pentamethyl-4-piperidinyl sebacate (CAS No.: 82919-37-7), 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, and mixtures thereof.

[0145] The UV stabilizer (or antioxidant) content may be up to 3% by weight, preferably up to 2% by weight, relative to the total weight of the composition according to the invention.

[0146] The dispersant may be selected from salts of polymers containing carboxylate and / or phosphate groups, polymer-functionalized trialkoxysilanes, and mixtures thereof, preferably from salts of polyethers containing carboxylate and / or phosphate groups, salts of polyesters containing carboxylate and / or phosphate groups, polyether-functionalized trialkoxysilanes, polyester-functionalized trialkoxysilanes, and mixtures thereof, more preferably from salts of polyesters containing phosphate groups, polyether-functionalized trialkoxysilanes (e.g., polyethylene glycol-functionalized trimethoxysilanes), and mixtures thereof.

[0147] Advantageously, components A and B each contain at least one dispersant (which may be the same or different).

[0148] The dispersant content may be up to 5% by weight relative to the total weight of the composition according to the invention, preferably between 0.5% by weight and 3% by weight.

[0149] Those skilled in the art typically use defoamers (or defoaming agents) to quickly eliminate bubbles that form during the preparation and application of two-component compositions containing polyol and polyisocyanate components.

[0150] The defoamer can be any defoamer commonly used in this two-component composition.

[0151] For example, the defoamer may be selected from zeolite (untreated). In particular, the defoamer may be a synthetic zeolite of type A, X and / or Y, preferably having a pore size between 3 Å and 5 Å, more preferably 3 Å.

[0152] The defoamer content may be up to 5% by weight relative to the total weight of the composition according to the invention, preferably between 0.5% by weight and 3% by weight.

[0153] Further features of the composition according to the invention

[0154] Advantageously, the volume ratio of component A to component B is contained between 0.25 and 4, preferably between 0.5 and 2, more preferably between 0.8 and 1.2, for example equal to 1.0.

[0155] According to one embodiment, the composition according to the invention comprises:

[0156] - Relative to the total weight of component A, at least one polyol P having a functionality of at least 4 in component A, comprising between 3% and 15% by weight.

[0157] - At least one polyol P' (different from polyol P) in component A, which is between 3% and 15% by weight relative to the total weight of component A.

[0158] - At least one polyisocyanate in component B, between 5% and 25% by weight relative to the total weight of component B.

[0159] - At least one thermally conductive filler in component A, comprising between 55% and 94% by weight relative to the total weight of component A, selected from metal silicates, metal oxides, metal hydroxides, metal and quasi-metal nitrides, metal and quasi-metal carbides, metal fillers, graphite, and mixtures thereof.

[0160] - At least one thermally conductive filler in component B, comprising between 55% and 94% by weight relative to the total weight of component B, selected from metal silicates, metal oxides, metal hydroxides, metal and quasi-metal nitrides, metal and quasi-metal carbides, metal fillers, graphite, and mixtures thereof.

[0161] - The crosslinking catalyst in component A, between 0.01 wt% and 0.2 wt%, relative to the total weight of component A, and

[0162] - Optionally, up to 10% by weight of one or more additives (in components A and / or B) relative to the total weight of the composition according to the invention, selected from plasticizers, solvents, rheology modifiers, pigments, adhesion promoters, hygroscopic agents, UV stabilizers (or antioxidants), dispersants, defoamers, and mixtures thereof.

[0163] The volume ratio of component A to component B is between 0.25 and 4.

[0164] Preferably, the composition according to the invention is substantially composed of the above-described ingredients. "Substantially composed of" means that, relative to the total weight of the composition, the composition contains less than 5% by weight, preferably less than 2% by weight, and even more preferably less than 1% by weight of ingredients other than those described above.

[0165] The components and their specific contents of this embodiment are as described above, including the embodiment and preferred features.

[0166] Specifically, the composition according to the invention comprises:

[0167] - Relative to the total weight of component A, at least one polyol P having a functionality of at least 4 in component A, ranging from 4% to 12% by weight, wherein said at least one polyol P is preferably an ethoxylated and / or propoxylated diamine comprising two primary amine groups.

[0168] - Relative to the total weight of component A, at least one polyol P' (different from polyol P) in component A, between 4% and 12% by weight, wherein the at least one polyol P' preferably comprises (or consists of) at least one polyether polyol selected from polyethylene glycol, polypropylene glycol and poly(ethylene glycol-propylene glycol) and at least one polyether polyol selected from ethoxylated and / or propoxylated diols.

[0169] - At least one polyisocyanate in component B, between 10% and 20% by weight relative to the total weight of component B, preferably selected from isocyanurates (monomers and / or polymers).

[0170] - Relative to the total weight of component A, at least one thermally conductive filler in component A, comprising between 75% and 85% by weight, selected from metal silicates, metal oxides, metal hydroxides, metal and quasi-metal nitrides, metal and quasi-metal carbides, metal fillers, graphite, and mixtures thereof, preferably selected from aluminosilicates, alumina, aluminum hydroxide, aluminum nitride, boron nitride, zinc oxide, magnesium oxide, and mixtures thereof.

[0171] - At least one thermally conductive filler in component B, comprising between 75% and 85% by weight relative to the total weight of component B, selected from metal silicates, metal oxides, metal hydroxides, metal and quasi-metal nitrides, metal and quasi-metal carbides, metal fillers, graphite, and mixtures thereof, preferably selected from aluminosilicates, alumina, aluminum hydroxide, aluminum nitride, boron nitride, zinc oxide, magnesium oxide, and mixtures thereof.

[0172] - The crosslinking catalyst in component A, at a rate between 0.05 wt% and 0.11 wt% relative to the total weight of component A, preferably selected from bismuth carboxylate, zinc carboxylate, and mixtures thereof, and

[0173] - Optionally, one or more additives (in component A and / or B) in between 0.1% and 5% by weight relative to the total weight of the composition according to the invention, selected from plasticizers, solvents, rheology modifiers, pigments, adhesion promoters, hygroscopic agents, UV stabilizers (or antioxidants), dispersants, defoamers, and mixtures thereof.

[0174] The volume ratio of component A to component B is between 0.8 and 1.2.

[0175] The composition according to the invention preferably comprises at least one surface-treated thermally conductive filler and at least one untreated thermally conductive filler.

[0176] Preferably, the composition according to the invention consists essentially of the above-described components.

[0177] The components of this embodiment and their specific contents are as described above, including the embodiment and preferred features.

[0178] Advantageously, the thermal conductivity of the composition according to the invention is between 1.0 W / mK and 3 W / mK, preferably between 1.5 W / mK and 2.5 W / mK, for example equal to about 2.0 W / mK.

[0179] "Approximately X" means that the value of X is greater than or less than 10% (the deviation from the value of X is greater than or less than 10%).

[0180] The thermal conductivity of the compositions according to the present invention can be measured according to ASTM D5470-12 (2017).

[0181] Advantageously, the compositions according to the invention have a tensile strength of at least 3.0 MPa, preferably at least 4.0 MPa, and more preferably at least 5.0 MPa. For example, the compositions according to the invention may have a tensile strength between 3.0 MPa and 20 MPa, preferably between 4.0 MPa and 10 MPa, and more preferably between 5.0 MPa and 7 MPa.

[0182] The tensile strength of the compositions according to the invention can be measured according to ISO 37 (2005), for example as described in Example 1 below.

[0183] Advantageously, the open time of the composition according to the invention at 23°C is between 15 minutes and 75 minutes.

[0184] Open time can be defined as the time between the start of mixing of components A and B and the start of curing of the composition, during which the user can apply the composition to a substrate for assembly without reducing adhesion.

[0185] The open time of the composition according to the present invention can be measured as described in Example 1 below.

[0186] Advantageously, the solidification time interval of the composition according to the invention at 23°C is less than 10 min, preferably less than or equal to 5 min.

[0187] The solidification interval corresponds to the difference between the open time and the solidification time of the composition. A short solidification interval is advantageous to the user, who does not have to wait a long time to comfortably manipulate the assembled substrates and store them outside the assembly line.

[0188] The solidification time of the composition according to the present invention can be measured as described in Example 1 below.

[0189] Advantageously, the composition according to the invention comprises less than 1% by weight, preferably less than 0.5% by weight, of diisocyanate monomer relative to the total weight of the composition.

[0190] "Diisocyanate monomer" refers to diisocyanate with a molar mass of less than 300 g / mol.

[0191] Each of components A and B in the composition according to the invention can be prepared individually by simply mixing their ingredients. Examples of preparation are described in Example 1.

[0192] Components A and B can be stored, for example, in a dual cartridge protected from air and moisture. The composition according to the invention can then be obtained by attaching, for example, a dynamic mixer to the dual cartridge.

[0193] Use of the composition according to the invention

[0194] The present invention also relates to the use of the compositions according to the invention as adhesives, preferably in assemblies intended for use in the manufacture of batteries, particularly for rechargeable batteries for electric or hybrid vehicles.

[0195] The compositions according to the present invention are as described above, including embodiments and preferred features.

[0196] Process for bonding substrates

[0197] The present invention also relates to a method for bonding substrates, comprising the following steps:

[0198] - Coat at least one surface of the substrate with the composition according to the invention as described above (including embodiments and preferred features), then

[0199] - Make the substrate come into contact.

[0200] It should be understood that the composition according to the invention is in an uncured state during the coating and contact steps.

[0201] The substrates can be the same or different.

[0202] The substrate to be implemented is diverse and is advantageously made of plastics, metals and / or composite materials, preferably metals.

[0203] The plastic material can be a polyolefin, such as polyethylene or polypropylene, or polyester.

[0204] Metallic materials can be pure or alloys, such as aluminum or steel.

[0205] The composite material can be a reinforced plastic material, such as fiber-reinforced plastics, particularly sheet molding composites (SMCs). The fibers in the fiber-reinforced plastic can be glass, carbon, aramid, or basalt fibers, preferably glass fibers. The fiber length can vary between 6 mm and 50 mm. The polymer in the reinforced plastic material can be polyester, polyolefin, epoxy, or vinyl ester resin, preferably polyester or polyolefin (e.g., polyethylene or polypropylene). The polymer in the reinforced plastic material is preferably unsaturated. The reinforcing plastic material may contain other compounds besides the fibers and polymer (e.g., fillers and / or catalysts).

[0206] Article

[0207] The present invention also relates to articles comprising (cured or uncured) compositions according to the invention as described above (including embodiments and preferred features), said compositions bonding said articles to at least two substrates.

[0208] Articles can be obtained using the method for bonding substrates according to the present invention.

[0209] The substrate is preferably as described above with respect to the method for bonding substrates according to the invention (including embodiments and preferred features), and in particular, the substrate is made of plastic, metal and / or composite material, preferably made of metal.

[0210] Advantageously, the product is a battery, preferably a rechargeable battery, especially for electric or hybrid vehicles.

[0211] All of the above embodiments can be combined with each other. In particular, the various components described above in the composition, and especially the preferred embodiments, can be combined with each other.

[0212] The following examples illustrate the present invention but are not intended to limit it. Example

[0213] Example 1 : Materials and methods

[0214] Material

[0215] Implement the following materials:

[0216] - PPG: Polypropylene glycol homopolymer diol with a number-average molecular weight of approximately 1000 g / mol and an OH value of approximately 110 mg KOH / g;

[0217] - DIANOL® 330 (from Arkema): Propoxylated 4,4'-isopropylidene diphenol (CAS: 37353-75-6), with a functionality of 2 (i.e., diol), an OH value of approximately 280 mg KOH / g, and a number-average molecular weight of approximately 400 g / mol;

[0218] - Tetraol: Propoxylated ethylenediamine, with a functionality of 4 (CAS: 25214-63-5), an OH value of approximately 470 mg KOH / g, and a number-average molecular weight of approximately 480 g / mol;

[0219] - BYK-W 903 (from BYK): A solution of polyester phosphate salt containing 40% non-volatile substances (after 10 minutes at 150°C).

[0220] - Pigment: 1,4-di-n-butyl-aminoanthraquinone;

[0221] - Borchi® Kat 315 (from Borchers): A bismuth neodecanoate-based catalyst;

[0222] - Siliporite® SA 1720 (from Arkema): Synthetic zeolite type A with a pore size of 3 Å;

[0223] - APYRAL®HC 502H (from Nabaltec): Aluminum trioxide with a hydrophobic surface treatment, having an average particle size d50 of about 30 μm and a thermal conductivity of about 20 W / mK;

[0224] - Al2O3: Spherical alumina with an average particle size d50 of 12.5 μm and a thermal conductivity of about 30 W / mK;

[0225] - Polyisocyanates: Aliphatic polyisocyanates based on hexamethylene diisocyanate trimers with an NCO content of approximately 23% and a hexamethylene diisocyanate monomer content of less than 0.5% (CAS: 28182-81-2; EC: 931-274-8; isocyanurates).

[0226] - PTSI: p-Toluenesulfonyl isocyanate;

[0227] - Dispersant: Polyethylene glycol-functionalized trimethoxysilane;

[0228] - ATH: Aluminum trioxide (untreated) with an average particle size d50 of about 30 μm and a thermal conductivity of about 20 W / mK.

[0229] Preparation of components A and B

[0230] Components A and B were prepared by mixing the ingredients shown in Table 1 below in a reactor with constant stirring at 50°C until homogenized, and then applying a vacuum (about 0.2-0.1 bar) to eliminate bubbles.

[0231] Open time

[0232] The composition to be tested was applied as beads approximately 0.5 cm in diameter to silicone paper at 23°C. Then, using the tip of a wooden tongue depressor, the surface of the composition was touched every minute. The open time was determined as the time it took for the tongue depressor to no longer sink into the beads.

[0233] Setting time

[0234] The solidification time was determined as the time required for the composition to have a shear strength of 1 MPa (at 23°C), measured between two INVAR / INVAR stainless steel supports.

[0235] The INVAR sample (25 mm wide × 100 mm long × 1.5 mm thick) was sanded laterally with P40 sandpaper (roughness 10-15 micrometers), degreased with heptane, and dried for 10 minutes.

[0236] The composition to be tested was applied at 23°C to the sanded end of the INVAR test specimen, with an area of ​​25 mm × 12.5 mm and a thickness of 0.8 mm. Then another test specimen was placed on the axis of the first one on the sanded surface, and the assembly was pressed down forcefully (for 6 specimens: weight > 4.5 kg) and held under pressure until the tensile test was performed.

[0237] The tensile test was performed by pulling the two free ends of the assembly at a speed of 5 mm / min using a force gauge (INSTRON model 1185) after a time period (from the time the composition was applied to the time the tensile test was performed). When this time period was sufficient to achieve a breaking force of 1 MPa (required to cause the assembly to break), this corresponds to the solidification time.

[0238] Setting time interval

[0239] The solidification time interval of the composition is calculated as the difference between the open time and the solidification time.

[0240] Thermal conductivity

[0241] Thermal conductivity was measured according to ASTM D5470-12 (2017).

[0242] Tensile strength

[0243] Tensile strength is measured at a constant speed of 100 mm / min according to ISO 37 (2005).

[0244] Specifically, the following conditions apply:

[0245] Use a standard dumbbell-shaped test specimen, type 2, as shown in ISO 37 (2005). The narrow portion of the dumbbell used has a length of 20 mm, a width of 4 mm, and a thickness of 3 to 4 mm.

[0246] To prepare dumbbells, the composition to be tested was applied to a Teflon mold and crosslinked for 14 days under standard conditions (23°C and 50% relative humidity).

[0247] The measurement principle involves stretching a standard test specimen in a tensile testing machine. The movable jaws of the tensile testing machine move at a constant speed of 100 mm / min, and the tensile strength (in MPa) is recorded. Tensile strength is the tensile stress at which the specimen breaks.

[0248] Repeated measurements were performed on 5 test samples, and the average value of the results was calculated.

[0249] Example 2: The compositions according to the present invention and comparative compositions

[0250] Composition 1 according to the invention is obtained by introducing components A and B into a twin barrel (to prevent air and moisture) and then mixing them at an ambient temperature (23°C) with a volume ratio equal to 1.0 using a dynamic mixer fixed at the tip of the twin barrel.

[0251]

[0252] Table 1: Components in components A and B, percentages are weight percentages relative to the total weight of components A or B, respectively.

[0253] Composition 2 according to the invention is prepared in a similar manner to composition 1, except that the two components are kept in a twin-cylinder at 50°C for 28 days and then mixed at ambient temperature using a dynamic mixer.

[0254] Comparative composition 3 was prepared in a similar manner to composition 1, except that APYRAL®HC 502H, Al2O3 and ATH were replaced by surface-treated (hydrophobic) calcium carbonate.

[0255] Comparative composition 4 was prepared similarly to composition 3, except that the two components were kept in a double cylinder at 50°C for 28 days and then mixed at ambient temperature using a dynamic mixer.

[0256] The properties of compositions 1-4 were then evaluated as described in Example 1, and the results are shown in Table 2.

[0257]

[0258] Table 2: Properties of Compositions 1-4

[0259] Composition 1 according to the invention provides a good balance between open time and settling time. Specifically, Composition 1 has an open time of 25 minutes (i.e., once the composition is applied using a dual-cylinder, the user has 25 minutes to bond the substrate without reducing adhesion) and a settling time of 28 minutes (i.e., once the composition is applied, 28 minutes are required to comfortably manipulate the assembly), corresponding to a settling interval of only 3 minutes. Therefore, once the composition is applied, for example on an assembly line, there is a long period available for bonding the substrate, and the bonded substrate can be comfortably manipulated shortly after the open time ends, allowing the bonded substrate to be stored outside the assembly line. Composition 1 also has good thermal conductivity and high tensile strength, making it suitable for use as an adhesive for battery assemblies.

[0260] Furthermore, the properties of the compositions according to the invention are maintained even after long storage periods above room temperature. In particular, composition 2 according to the invention has a slightly longer open time than composition 1 (which is advantageous), while maintaining a 3-minute solidification interval and retaining the same thermal conductivity and tensile strength.

[0261] However, when the thermally conductive filler was replaced by surface-treated calcium carbonate (comparative compositions 3 and 4), the open time was significantly reduced, while the solidification time interval was significantly increased.

[0262] Therefore, the compositions according to the invention are advantageously suited for assembly lines requiring long open times and short solidification intervals. Furthermore, the compositions according to the invention possess good thermal conductivity and high tensile strength, making them suitable for battery assemblies.

Claims

1. A two-component thermally conductive composition comprising: - Component A, which comprises: o At least one polyol P having a functionality of at least 4, and o At least one thermally conductive filler; and - Component B, which comprises: o at least one polyisocyanate, and o At least one thermally conductive filler; The at least one thermally conductive filler in each of components A and B is selected from metal silicates, metal oxides, metal hydroxides, metal and quasi-metal nitrides, metal and quasi-metal carbides, metal fillers, graphite, and mixtures thereof. At least one of the thermally conductive fillers in the composition is a surface-treated thermally conductive filler with a hydrophobic surface treatment.

2. The two-component thermally conductive composition according to claim 1, wherein the at least one polyol P is selected from polyester polyols, polyether polyols, and mixtures thereof, preferably from polyether polyols.

3. The two-component thermally conductive composition according to claim 2, wherein the polyether polyol is an ethoxylated and / or propoxylated diamine, the diamine comprising two primary amine groups.

4. The two-component thermally conductive composition according to any one of claims 1 to 3, wherein the polyol P has a number-average molecular weight between 200 g / mol and 2000 g / mol.

5. The two-component thermally conductive composition according to any one of claims 1 to 4, wherein the component A further comprises at least one polyol P' different from the polyol P.

6. The two-component thermally conductive composition according to claim 5, wherein the at least one polyol P' comprises a polyether polyol, wherein the polyether polyol is a polyoxyalkylene oxide.

7. The two-component thermally conductive composition according to claim 5 or 6, wherein the at least one polyol P' comprises a polyether polyol, said polyether polyol being an ethoxylated and / or propoxylated diol.

8. The two-component thermally conductive composition according to any one of claims 1 to 7, wherein the at least one polyisocyanate is selected from aliphatic polyisocyanates.

9. The two-component thermally conductive composition according to any one of claims 1 to 8, wherein the at least one polyisocyanate is selected from biuret, isocyanurate, adducts with polyols and mixtures thereof, preferably selected from isocyanurate, and the at least one polyisocyanate is monomeric and / or polymeric.

10. The two-component thermally conductive composition according to any one of claims 1 to 9, wherein at least one of the thermally conductive fillers in the composition is a surface-treated thermally conductive filler, and at least one of the thermally conductive fillers in the composition is an untreated thermally conductive filler.

11. The two-component thermally conductive composition according to any one of claims 1 to 10, wherein the at least one thermally conductive filler in each of components A and B is selected from aluminosilicates, alumina, aluminum hydroxide, aluminum nitride, boron nitride, zinc oxide, magnesium oxide, and mixtures thereof.

12. The two-component thermally conductive composition according to any one of claims 1 to 11, wherein the total content of the at least one thermally conductive filler in each of components A and B is respectively between 55% by weight and 94% by weight relative to the total weight of each of components A and B.

13. The two-component thermally conductive composition according to any one of claims 1 to 12, wherein component A comprises a crosslinking catalyst.

14. The two-component thermally conductive composition according to claim 13, wherein the crosslinking catalyst content in component A is between 0.01% by weight and 0.2% by weight relative to the total weight of component A.

15. Use of the two-component thermally conductive composition according to any one of claims 1 to 14 as an adhesive, preferably in an assembly intended for use in manufacturing a battery.

16. A method for bonding a substrate, comprising the following steps: - Coat at least one surface of the substrate with the two-component thermally conductive composition according to any one of claims 1 to 14, then - Make the substrate come into contact.

17. An article comprising a two-component thermally conductive composition according to any one of claims 1 to 14, wherein the composition bonds at least two substrates of the article.

Images