Moisture-hardening sealant composition for high-temperature exposure

Description

FIELD OF INVENTION

[0001] The present invention relates to a moisture-curable sealant composition, more specifically a silylated sealant composition, usable particularly in the field of construction, and which is capable of forming, after curing, an adhesive joint whose stability after exposure to high temperature is improved. TECHNICAL BACKGROUND

[0002] Sealants are widely used in the construction industry, particularly due to their mechanical properties. For example, their resistance to deformation makes them ideal for structural bonding applications such as bonding concrete elements in civil engineering (like the construction of bridges or concrete buildings), or for sealing or caulking gaps between two building components. Furthermore, their elastic properties allow for joints that are stable against dimensional changes caused by various external factors, such as temperature fluctuations, or flexible enough to deform and adapt to the relative movements of the substrates between which they are applied.

[0003] The resistance to deformation of a sealant is, in practice, often represented by its elastic modulus (expressed in Pa). In a tensile test of a sealant specimen, this modulus is defined as the ratio of the stress that must be applied to the specimen to obtain a given deformation (also called elongation or stretch). Elongation is therefore the length to which a sealant specimen can stretch, expressed as a percentage of its initial size. The elastic modulus is often measured for an elongation of 100%.

[0004] The elastic properties of a sealant are generally quantified by its elongation at break. This elongation (expressed as a percentage) is defined, in a tensile test of a sealant specimen, as the elongation measured for the specimen at the moment of its rupture.

[0005] Apart from their mechanical properties, sealants used in construction are valued for their ability to adhere to a wide variety of substrates and their resistance to weather conditions (UV, ozone, water).

[0006] A moisture-curing adhesive sealant composition, such as a silylated sealant composition, comprises a moisture-curing prepolymer containing alkoxysilane reactive groups, typically terminal. The reaction of these reactive groups with water from atmospheric or substrate humidity (known as the crosslinking reaction) allows, after the sealant is applied, the formation of a solid, three-dimensional polymer network, which imparts the desired properties, particularly mechanical ones, to the resulting adhesive joint.

[0007] The international application under PCT WO 2018 / 215463 discloses such a composition, which comprises, in addition to a silylated polymer with an alkoxysilane group and a filler, 0.68% to 1% by weight of a silsesquioxane with a phenyl group and an alkoxy group.

[0008] The international application under PCT WO 2018 / 215463 discloses a composition for the preparation of a low modulus silylated sealant having stable mechanical properties and used in the field of construction as a sealant, comprising a silylated polymer including at least one terminal alkoxysilyl group, a polysilsesquioxane including Si-phenyl groups and alkoxysilyl-Si(OR) groups, a calcium carbonate and a condensation catalyst.

[0009] US patent 2019 / 048190 describes a composition used as an adhesive or sealant, primarily in the construction industry. The composition comprises a polymer including an alkoxysilyl terminal group, a silicone resin including phenyl and methoxysilyl SiOMe groups, a condensation catalyst, and calcium carbonate.

[0010] The international application under PCT WO 2019 / 134863 discloses a low modulus silicone composition intended for use as an adhesive or sealant, particularly in the field of construction, comprising a silicone having hydroxyl functions, calcium carbonate, a polysiloxane comprising amine functions and a condensation catalyst.

[0011] Finally, US patent 2012 / 009366 describes a low modulus silicone composition intended for use as a sealant or sealant, particularly in the field of window assembly, comprising an isobutylene-styrene copolymer functionalized with a methoxysilyl group, a silicone resin comprising phenyl and hydroxyl groups, and a condensation catalyst.

[0012] Among the many possible applications of sealants in the construction and industrial sectors, some involve applications where the adhesive joint is located outdoors, in contact with the atmosphere, or even under a glass wall. Such joints are thus likely to be exposed for extended periods to high temperatures due to solar radiation and the climate of hot countries, typically reaching temperatures of up to 90°C. In other industrial applications, adhesive joints may frequently be exposed to even higher temperatures, up to 140°C.

[0013] There is therefore a need for such adhesive joints to maintain their advantageous mechanical properties over time, particularly resistance to deformation and elasticity.

[0014] The present invention therefore aims to provide a sealant composition comprising an alkoxysilane group polymer, which, after crosslinking, allows the formation of an adhesive joint which exhibits improved stability when exposed to high temperatures.

[0015] Another object of the present invention is to provide a sealant composition comprising an alkoxysilane group polymer which, after crosslinking and after long-term exposure of the adhesive joint to a high temperature, maintains the resistance to deformation and elasticity properties at a level acceptable in practice, in particular its elongation at break and elastic modulus. DESCRIPTION OF THE INVENTION

[0016] The invention therefore relates to a mastic composition comprising: of 3 to 80% of a polymer (A) with an alkoxysilane group, of at least 25% of a carbonate filler (B), and of 0.5 to 20% of a polysiloxane resin (C) comprising, as groups directly linked to the silicon atom: at least one phenyl group; and at least one group selected from a hydroxyl and an aminoalkylene group of formula: -R' 0< - NH-R" 0< ; in which: R' 0< is an alkylene radical comprising from 2 to 5 carbon atoms, and R" 0< is a hydrogen atom or an alkyl radical comprising from 1 to 5 carbon atoms; and of 0.1 to 1% of a crosslinking catalyst (D); said percentages being expressed in weight on the basis of the total weight of said composition.

[0017] It has indeed been found that this sealant composition, the subject of the invention, makes it possible to obtain, after curing, an adhesive joint that better retains its resistance to deformation and elasticity properties, in particular its elastic modulus and elongation at break, after being exposed for one week to temperatures between 80 and 150°C. These elastic properties are, in particular, surprisingly significantly improved compared to those of the sealant composition the subject of WO 2018 / 215463 cited above. Polymer (A) with alkoxysilane group :

[0018] The sealant composition according to the invention comprises from 3 to 80% by weight of an alkoxysilane group polymer, based on the total weight of said composition.

[0019] The alkoxysilane group polymer is a polymer which comprises at least one, preferably at least two groups of formula (I): in which: R4< and R5<, whether identical or different, each represent a linear or branched alkyl radical comprising 1 to 4 carbon atoms; and p is an integer equal to 0, 1 or 2; and, preferably: R 4< and R 5< each represent a methyl radical; and p is equal to 0 or 1.

[0020] Preferably, the group(s) of formula (I) are groups located at the ends of the main chain of the polymer, also called terminal groups.

[0021] Preferably, the main chain of the polymer comprising at least one alkoxysilane group is chosen from polyurethanes, polyethers and their mixtures.

[0022] A polymer containing at least one alkoxysilane group may have a number-average molecular weight ranging from 500 to 50,000 g / mol, preferably from 700 to 20,000 g / mol. The number-average molecular weight of polymers can be measured by methods well known to those skilled in the art, for example, by size-exclusion chromatography using polyethylene glycol standards.

[0023] According to one embodiment, the polymer (A) comprising at least one alkoxysilane group is chosen from the polymers of formulas (II), (III) or (IV) as defined below, and their mixtures: [Chem 2] (R 5< O) 3-p (R 4< ) p Si - R 0< - [OR 2< ] n - R 0< - Si(R 4< )p(OR 5< ) 3-p (II) in which: R0 represents a linear or branched alkylene divalent radical comprising 3 to 6 carbon atoms; R1 represents a hydrocarbon divalent radical comprising 5 to 15 carbon atoms, which may be aromatic or aliphatic, linear, branched, or cyclic; R2 represents a linear or branched alkylene divalent radical comprising 2 to 4 carbon atoms; R3 represents a linear or branched alkylene divalent radical comprising 1 to 6 carbon atoms, R3 preferably representing methylene or n-propylene radicals; R4 and R5 are as defined previously; R6 represents a hydrogen atom, a phenyl radical, a linear, branched, or cyclic alkyl radical comprising 1 to 6 carbon atoms, or a 2-succinate radical of formula: in which R7 is a linear or branched alkyl radical comprising from 1 to 6 carbon atoms; n is an integer such that the number-average molecular weight of the polyether block of formula -[OR2]n - ranges from 300 g / mol to 40,000 g / mol in the polymers of formulas (II), (III), and (IV); m1 is zero or an integer; n and m1 are such that the number-average molecular weight of the polymer of formula (III) ranges from 500 g / mol to 50,000 g / mol, preferably from 700 g / mol to 20,000 g / mol; m is a non-zero integer; n and m are such that the number-average molecular weight of the polymer of formula (IV) ranges from 500 g / mol to 50,000 g / mol, preferably from 700 g / mol to 20,000 g / mol; p is such as defined previously.

[0024] Preferably, the radical R 1< of formulas (III) and (IV) is chosen from one of the following divalent radicals whose formulas below show the 2 free valences: a) the divalent radical derived from isophorone diisocyanate (IPDI): b) the divalent radical derived from 4,4'- and 2,4'-dicyclohexylmethane diisocyanate (HMDI): c) the radical derived from 2,4- and 2,6-toluene diisocyanate (TDI) d) the radical derived from 4,4'- and 2,4'-diphenylmethane diisocyanate (MDI) e) the radical derived from m-xylylene diisocyanate (m-XDI) f) the radical derived from hexamethylene diisocyanate (HDI) [Chem 9] -(CH 2 ) 6 -

[0025] Preferably, the radical R 1< of formulas (III) and (IV) is the divalent radical derived from isophorone diisocyanate or xylylene diisocyanate.

[0026] Formula polymers (II) can be obtained by hydrosilylation of polyether diallylether according to a process described for example in document EP 1829928.

[0027] Examples of polymers conforming to formula (II) include: MS POLYMER ™< S303H (available from KANEKA) corresponds to a polyether comprising two formula (I) groups of the dimethoxy type (p is equal to 1 and R 4< represents a methyl group) having a number average molecular mass of approximately 22,000 g / mol and a viscosity of 12.5 Pa.s at 23°C; MS POLYMER ™< S227 (available from KANEKA) corresponds to a polyether comprising two formula (I) groups of the dimethoxy type (p is equal to 1, R 5< and R 4< each represent a methyl group) having a number average molecular mass of approximately 27,000 g / mol, and a viscosity of 34 Pa.s at 23°C.

[0028] Formula (III) polymers can be obtained by a process described in documents EP 2336208 and WO 2009 / 106699.

[0029] Examples of polymers conforming to formula (III) include: GENIOSIL ®< STP-E10 (available from Wacker): polyether comprising two (I) dimethoxy type groups (m 1 equals 0, p equals 1 and R 4< and R 5< represent a methyl group) having a number-average molecular mass of about 8,889 g / mol where R 3< represents a methylene group; GENIOSIL ®< STP-E30 (available from Wacker): polyether comprising two formula (I) dimethoxy type groups (m 1 equals 0, p equals 1 and R 4< and R 5< represent a methyl group) having a number-average molecular mass of about 14,493 g / mol where R 3< represents a methylene group; GENIOSIL ®< STP-E35 (available from Wacker): polyether comprising two formula (I) groups of the trimethoxy type (m 1 equals 0, p equals 0 and R 5< represents a methyl group), having a number-average molecular mass of about 32,240 g / mol where R 3< represents an n-propylene group, and having a viscosity of about 30,000 mPa.s at 23°C; SPUR+ ®< 1050MM (available from MOMENTIVE): polyether polyurethane comprising two formula (I) groups of the trimethoxy type (m 1 not equal to 0, p equal to 0 and R 5< represents a methyl group) having a number-average molecular weight of approximately 21,000 g / mol where R 3< represents an n-propylene group; SPUR+ ®< Y-19116 (available from MOMENTIVE): polyurethane comprising two formula (I) groups of the trimethoxy type (m 1 not equal to 0 and R 5< represents a methyl group) having a number-average molecular weight ranging from 15,000 to 17,000 g / mol where R 3< represents an n-propylene group; DESMOSEAL ®< S XP 2636 (available from BAYER): polyurethane comprising two formula (I) groups of the trimethoxy type (m 1 not equal to 0, p equal to 0 and R 5< represents a methyl group) having a number-average molecular weight of approximately 15,038 g / mol where R 3< represents an n-propylene group. .

[0030] Polymers of formula (IV) can be obtained according to the process comprising: a) the reaction of a polyether polyol with the following formula: with a stoichiometric excess of diisocyanate of the following formula: NCO-R 1< -NCO to form a polyurethane-polyether block having at least two -NCO terminal groups, said block preferably comprising 1.5% to 1.9% by weight of -NCO group, then b) reaction between a block obtained in the previous step with a stoichiometric amount or a slight excess of a □-, □- or □- aminosilane having the following formula: [Chem 11] (R 5< O) 3-p (R 4< ) p Si-R 3< -NH-R 6<

[0031] Such a process is described for example in WO 2013 / 136108.

[0032] Among the polymers corresponding to formula (IV), we can mention SPUR+ 1015 LM (available from MOMENTIVE) corresponding to a polyether polyurethane comprising two formula (I) groups of the trimethoxy type (p is equal to 0, R 5< represents a methyl group) having a number molecular mass of approximately 25,000 g / mol and a viscosity of 50 Pa at 23°C.

[0033] The composition according to the invention may comprise a polymer of formula (II) or a mixture of different polymers of formula (II).

[0034] It may also include a polymer of formula (III) or a mixture of different polymers of formula (III).

[0035] It may also include a polymer of formula (IV) or a mixture of different polymers of formula (IV).

[0036] According to a preferred embodiment, the composition according to the invention comprises a polymer of formula (II) and a polymer of formula (III).

[0037] According to one embodiment, the composition according to the invention comprises from 5% to 60% by weight, preferably from 5% to 50% by weight, advantageously from 10% to 50%, for example from 10% to 40% by weight, advantageously from 20% to 30%, in particular from 22% to 24% by weight of at least one polymer comprising an alkoxysilane group, relative to the total weight of said composition. Carbonate charge (B) :

[0038] The mastic composition according to the invention comprises at least 25% by weight of a carbonate filler, based on the total weight of said composition.

[0039] According to one embodiment, the carbonate charge is chosen from alkali or alkaline-earth metal carbonates and their mixtures, preferably the carbonate charge is calcium carbonate.

[0040] Calcium carbonate can be made hydrophobic, for example with calcium stearate or an analog, which imparts partial or total hydrophobicity to the calcium carbonate particles. The degree of hydrophobicity of the calcium carbonate can impact the rheology of the composition. Furthermore, the hydrophobic coating can prevent the calcium carbonate from absorbing the other components of the composition and rendering them ineffective. The hydrophobic coating of the calcium carbonate can represent from 0.1% to 3.5% by weight, relative to the total weight of calcium carbonate.

[0041] The calcium carbonate that can be used in the present invention preferably has a particle size ranging from 0.1 to 400 µm, more preferably from 1 to 400 µm, more preferably from 10 to 350 µm, more preferably from 50 to 300 µm.

[0042] As an example of calcium carbonate, we can cite MIKHART ®< 1T (available from the company La Provençale).

[0043] According to a preferred embodiment, the composition according to the invention may comprise from 25% to 80% by weight, preferably from 40% to 60% by weight, in particular from 45% to 55% by weight of the carbonate filler, relative to the total weight of the composition. Polysiloxane resin (C) :

[0044] The sealant composition according to the invention comprises from 0.5 to 20% of a polysiloxane resin (C) comprising, as groups directly linked to the silicon atom: at least one phenyl group; and at least one group selected from a hydroxyl and an aminoalkylene group of formula: -R' 0< - NH-R" 0< ; in which R' 0< is an alkylene radical comprising from 2 to 5 carbon atoms, and R" 0< is a hydrogen atom or an alkyl radical comprising from 1 to 5 carbon atoms.

[0045] Polysiloxane resins are polymer resins or oligomers whose repeating pattern is derived from a siloxane compound of formula: R'R"SiO in which R' and R" are organic or mineral substituents directly linked to the silicon atom.

[0046] The said repeating pattern can be understood, to constitute a polysiloxane resin, in a linear chain, in a two-dimensional structure or in a three-dimensional structure, such as a silsesquioxane.

[0047] According to one embodiment, polysiloxane resin (C) is a silsesquioxane.

[0048] Silsesquioxanes are polysiloxanes that can adopt a polyhedral or polymeric structure, with Si-O-Si bonds. They typically have the following general structure: [RSiO 3 / 2 ] t where R represents an organic radical, and t is an integer that can vary from 6 to 12, preferably t equal to 6, 8, 10 or 12.

[0049] According to a preferred embodiment, polysiloxane resin (C) is a silsesquioxane having a polyhedral structure (or POSS for "Polyhedral Oligomeric Silsesquioxane" in English).

[0050] Even more preferably, silsesquioxane (C) corresponds to the following general formula (V): in which each of R' 1< to R' 8< represents, independently of each other, a group chosen from: a hydrogen atom, a hydroxy group or an aminoalkylene group of formula: -R' 0< - NH-R" 0< ; in which R' 0< and R" 0< are as defined previously;a radical selected from the group consisting of a linear or branched C1-C4 alkoxy radical, a linear or branched alkyl radical comprising 1 to 30 carbon atoms, an alkenyl radical comprising 2 to 30 carbon atoms, an aromatic radical comprising 6 to 30 carbon atoms, an allyl radical comprising 3 to 30 carbon atoms, an aliphatic cyclic radical comprising 3 to 30 carbon atoms, an acyl radical comprising 1 to 30 carbon atoms, and a group -OSiR' 9< R' 10< in which R' 9< and R' 10< each represent, independently of each other, a hydrogen atom or a radical selected from the group consisting of a linear or branched C1-C4 alkyl, a linear or branched C1-C4 alkoxy, and a C1-C4 alkenyl 2-C4, a phenyl, a C3-C6 allyl radical, a C3-C8 cyclic aliphatic radical, and a C1-C4 acyl radical;provided that: at least one radical among the radicals R' 1< to R' 8< is the phenyl radical; and at least one radical among the radicals R' 1< to R' 8< is either a hydroxyl group or an aminoalkylene group of the formula: -R' 0< - NH-R" 0< ; in which R' 0< and R" 0< are as defined previously. ;

[0051] Preferably, in the aforementioned formula (V), each from R' 1< to R' 8< represents, independently of each other, a group chosen from: a hydrogen atom, a hydroxyl group, or an aminoalkylene group of formula: -R' 0< - NH-R" 0< ; in which R' 0< and R" 0< are as defined previously; a radical selected from the group consisting of a linear or C1-C4 branched alkoxy radical, a linear or branched alkyl radical comprising from 1 to 12 carbon atoms, preferably from 1 to 8 carbon atoms, and for example from 1 to 5 carbon atoms, an aromatic radical comprising from 6 to 12 carbon atoms, and a group -OSiR' 9< R' 10< in which R' 9< and R' 10< each represent, independently of each other, a hydrogen atom or a radical selected from a linear or C1-C4 branched alkyl, for example methyl or ethyl, preferably methyl, provided that : at least one radical among the radicals R' 1< to R' 8< is a phenyl radical; and at least one radical among the radicals R' 1< to R' 8< is either a hydroxy group or an aminoalkylene group of formula: -R' 0< - NH-R" 0< ; in which R' 0< and R" 0< are as defined above.

[0052] According to one embodiment, the polysiloxane resin (C) comprises, as a group directly bonded to the silicon atom, at least one hydroxyl group. The content of corresponding Si-OH motifs in the polysiloxane resin (C) is generally between 4 and 8% by weight of said motifs, based on the weight of (C).

[0053] According to another embodiment, the polysiloxane resin (C) comprises, as a group directly bonded to the silicon atom, at least one aminoalkylene group of formula: -R' 0< - NH-R" 0< , wherein: R' 0< is an alkylene radical comprising 2 to 5 carbon atoms, and R" 0< is a hydrogen atom or an alkyl radical comprising 1 to 5 carbon atoms.

[0054] According to an even more preferred variant, R' 0< is an alkylene radical comprising 2 to 3 carbon atoms and R" 0< is a hydrogen atom.

[0055] The content of corresponding Si-R' 0< - NH-R" 0< motifs in polysiloxane resin (C) is generally such that the weight of resin (C) per mole of NH is between 200 and 300 g.

[0056] According to yet another embodiment, the polysiloxane resin (C), in particular when it is a silsesquioxane (C), preferably of formula (V), has a number average molecular mass ranging from 400 g / mol to 4000 g / mol, preferably from 500 g / mol to 2500 g / mol.

[0057] The number-average molecular weights of polysiloxane resins, particularly silsesquioxanes, can be measured by methods well known to those skilled in the art, for example by size-exclusion chromatography using polystyrene-type standards.

[0058] As an example of polysiloxane (C), the following two products available from DOW CORNING can be cited: DOWSIL ®< 3055 (CAS number: 1242619-23-3) is a silsesquioxane with a number-average molecular weight between 500 and 1000 g / mol, and which comprises at least one phenyl group and at least one aminopropyl group directly bonded to the silicon atom; the Si-aminopropyl motif content being such that the weight of said silsesquioxane per mole of NH is between 250 and 270 g; DOWSIL ®< RSN-0217 (CAS number: 63148-53-8) is a polysiloxane with a number-average molecular weight between 1500 and 2500 g / mol, and which comprises at least one phenyl group and at least one hydroxyl group directly bonded to the silicon atom; the content of corresponding Si-OH motifs in said polysiloxane being 6% by weight of said motifs, based on the weight of said polysiloxane.

[0059] According to a preferred embodiment, the composition according to the invention may comprise from 0.5 to 10%, preferably from 0.5 to 5%, in particular from 0.5 to 1.5% by weight of polysiloxane resin (C), relative to the total weight of composition. Crosslinking catalyst (D) :

[0060] The mastic composition according to the invention comprises from 0.1 to 1% of a crosslinking catalyst (D), based on the total weight of said composition.

[0061] The catalyst (D) can be any catalyst known to those skilled in the art for the condensation of silanol. Examples of such catalysts include: aminosilanes such as N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (commercially available as SILQUEST®< A-1120 from MOMENTIVE) or 3-aminopropyltrimethoxysilane, organic titanium derivatives such as titanium acetyl acetonate (commercially available as TYZOR®< AA75 from DU PONT DE NEMOURS), aluminum such as aluminum chelate (commercially available as K-KAT®< 5218 from KING INDUSTRIES), amines such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) or 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 2,2'-morpholine diethyl ether (DMDEE), the 1,4-Diazabicyclo[2.2.2]octane (DABCO), tin-based catalysts such as NEOSTANN®< S-1 or TIB-KAT®< 216 (available from KANEKA or TIB CHEMICALS respectively). These tin-based catalysts are particularly suitable for silylated polymers of formula (II).

[0062] The catalyst(s) preferably represent 0.2% to 0.8% by weight, relative to the total weight of the composition. Other additives :

[0063] According to one embodiment, the composition comprises, in addition to ingredients (A), (B), (C) and (D) from 0% to 30% by weight, in particular from 0.5% to 30% by weight, preferably from 10% to 30% by weight, at least one additive selected from plasticizers, solvents, pigments, adhesion promoters, moisture absorbers, UV stabilizers (or antioxidants), rheological agents as well as fillers other than carbonated fillers.

[0064] The composition according to the invention may in particular include at least one plasticizing agent at a rate of 5% to 30% by weight, preferably 10% to 30% by weight, preferably 15% to 25% by weight relative to the total weight of said composition.

[0065] As an example of a usable plasticizing agent, any plasticizing agent commonly used in the field of sealant compositions can be used.

[0066] Preferably, we use: diisodecyl phthalate, as marketed under the name PALATINOL™< DIDP by BASF, an alkylsulfonic acid and phenol ester, as marketed under the name MESAMOLL ®< by LANXESS, diisononyl-1,2-cyclohexanedicarboxylate, as marketed under the name HEXAMOLL DINCH ®< by BASF, pentaerythritol tetravalerate, as marketed under the name PEVALEN™< by PERSTORP.

[0067] The composition according to the invention may also include 0% to 5% by weight of a solvent, preferably a solvent volatile at room temperature (approximately 23°C). The volatile solvent may, for example, be chosen from alcohols volatile at room temperature, such as ethanol or isopropanol. The volatile solvent allows, for example, a reduction in the viscosity of the composition and makes it easier to apply. The volatile nature of the solvent ensures that the joint, obtained after the composition has hardened, no longer contains any solvent. Thus, the solvent does not, for example, have a negative influence on the hardness of the joint.

[0068] The composition according to the invention may also include up to 3% by weight of a pigment selected from organic or inorganic pigments.

[0069] For example, the pigment can be TiO2, in particular KRONOS® <2059 marketed by the company KRONOS.

[0070] The composition according to the invention may also include up to 3% by weight of an adhesion promoter which may be, for example, an aminosilane, such as 3-aminopropyltrimethoxysilane (also known as AMMO).

[0071] The composition according to the invention may also include up to 3% by weight of a moisture absorber which may be selected from vinyltrimethoxysilane (VTMO), vinyltriethoxysilane (VTEO), alkoxyarylsilanes, such as GENIOSIL ®< XL 70 available from the WACKER Company.

[0072] The composition according to the invention may also include UV stabilizers or antioxidants, including benzotriazoles, benzophenones, so-called hindered amines such as bis(2,2,6,6,-tetramethyl-4-piperidyl)sebaceate, and mixtures thereof. Examples include the products TINUVIN®< 328 or TINUVIN™< 770 marketed by BASF.

[0073] The composition according to the invention may also comprise from 1% to 30% by weight (relative to the total weight of the composition according to the invention) of a rheological agent, preferably from 5% to 30% by weight, more preferably from 10% to 25% by weight

[0074] As an example of a rheological agent, one can cite any rheological agent commonly used in the field of mastic compositions.

[0075] Preferably, one or more rheological agents are used, chosen from among the thixotropic agents, and more preferably from: PVC plastisols, corresponding to a suspension of PVC in a plasticizing agent miscible with PVC, obtained in situ by heating at temperatures ranging from 60°C to 80°C. These plastisols may include those described in particular in the book "Polyurethane Sealants," Robert M. Evans, ISBN 087762-998-6; fumed silica; urea derivatives resulting from the reaction of an aromatic diisocyanate monomer such as 4,4'-MDI with an aliphatic amine such as butylamine. The preparation of such urea derivatives is described in particular in French patent application FR 1 591 172; and micronized amide waxes, such as CRAYVALLAC SLX marketed by ARKEMA.

[0076] The composition according to the invention may finally comprise from 0% to 30% by weight, preferably from 0% to 10%, even more preferably from 1% to 10% by weight (relative to the total weight of the composition) of a filler other than the carbonated filler (D) defined previously.

[0077] Said charge other than the carbonate charge (D) may be chosen from organic charges, inorganic charges and mixtures thereof.

[0078] As organic filler(s), any organic filler(s), and in particular polymeric filler(s), typically used in the field of sealant compositions, can be used.

[0079] Examples of materials that can be used include polyvinyl chloride (PVC), polyolefins, rubber, ethylene vinyl acetate (EVA), and aramid fibers such as Kevlar®.

[0080] Hollow microspheres made of expandable or non-expandable thermoplastic polymers can also be used. Hollow microspheres made of vinylidene chloride / acrylonitrile are a notable example.

[0081] The average particle size of the filler(s) usable as filler other than the carbonate filler (D) is preferably less than or equal to 10 microns, more preferably less than or equal to 3 microns, in order to avoid their sedimentation in the composition according to the invention during its storage.

[0082] The average particle size is measured for a volumetric particle size distribution corresponding to 50% by volume of the analyzed particle sample. When the particles are spherical, the average particle size corresponds to the median diameter (D50 or Dv50), which is the diameter such that 50% of the particles by volume have a size smaller than that diameter. In this application, this value is expressed in micrometers and determined according to Standard NF ISO 13320-1 (1999) by laser diffraction on a MALVERN-type instrument.

[0083] Preferably, the charge other than the carbonate charge (D) is an inorganic charge.

[0084] Inorganic fillers can take the form of particles with diverse geometries. For example, they can be spherical, fibrous, or have an irregular shape.

[0085] According to one embodiment, the filler is chosen from sand, glass beads, glass, quartz, barite, alumina, mica, talc. Preferably, the filler other than the carbonate filler (D) is chosen from sand and glass beads.

[0086] The sand that can be used in the present invention preferably has a grain size ranging from 0.1 to 400 µm, preferably from 1 to 400 µm, preferably still from 10 to 350 µm, preferably still from 50 to 300 µm.

[0087] The glass beads that can be used in the present invention preferably have a particle size ranging from 0.1 to 400 µm, preferably from 1 to 400 µm, preferably still from 10 to 350 µm, preferably still from 50 to 300 µm.

[0088] According to a preferred embodiment, the composition according to the invention comprises, and preferably consists essentially of: 10 to 50% by weight of Polymer (A) with alkoxysilane group; 25 to 80% by weight of carbonate filler (B); 0.5 to 5% by weight of polysiloxane resin (C); 0.2 to 0.8% by weight of crosslinking catalyst (D); and 0.5 to 30% of an additive chosen from plasticizers, solvents, pigments, adhesion promoters, moisture absorbers, UV stabilizers, rheological agents as well as fillers other than carbonate fillers.

[0089] According to another preferred embodiment, the composition according to the invention comprises, and preferably consists essentially of: 20 to 30%, by weight of Polymer (A) with alkoxysilane group; 40 to 60% by weight of carbonate filler (B); 0.5 to 1.5% by weight of polysiloxane resin (C); 0.2 to 0.8% by weight of crosslinking catalyst (D); and 10 to 30% of an additive chosen from plasticizers, solvents, pigments, adhesion promoters, moisture absorbers, UV stabilizers, rheological agents as well as fillers other than carbonate fillers.

[0090] The composition of the invention can be prepared by simply mixing its ingredients. Preferably, the alkoxysilane polymer(s) (A) are mixed with the polysiloxane resin (C) in a suitable container, then with the filler(s) (carbonate (B) and other fillers) at a temperature ranging from 5°C to 80°C, preferably under an inert atmosphere. Next, the moisture absorber, then the other additives, and finally the catalyst (D) are introduced into the mixer.

[0091] The present invention also relates to the use of the composition as defined above, as an adhesive, sealant or coating, preferably as a sealant, for example as a construction sealant.

[0092] The substrates involved are very varied, and preferably chosen from among concrete, a metal such as aluminium, or even steel.

[0093] The compound can be used in the construction industry, for example, to create sealing and expansion joints in buildings, particularly between concrete / concrete substrates. It can also be used in industry, for example in the automotive industry, to assemble equipment such as tunnel furnaces used in car painting.

[0094] The following examples are given purely to illustrate the invention and should not be interpreted to limit its scope. EXAMPLES Example A (reference) :

[0095] The sealant composition listed in Table 1 below was prepared by mixing the ingredients according to the procedure described above. The ingredient content is indicated as a percentage by weight. Measurement of the elongation at break of the adhesive joint (obtained at the initial time) :

[0096] The principle of the measurement consists of stretching in a tensile machine, whose moving jaw moves at a constant speed of 100 mm / minute, a standard specimen made of the cross-linked composition (constituent of the adhesive joint) and recording, at the moment when the specimen breaks, the applied tensile stress (in MPa) as well as the elongation of the specimen (in %).

[0097] The standard test specimen is dumbbell-shaped, as illustrated in the international standard ISO 37. The narrow part of the dumbbell used has a length of 20 mm, a width of 4 mm and a thickness of 500 µm.

[0098] To prepare the test specimen, the mastic composition is applied in a Teflon mold and left to cure for 15 days at 23°C and 50% relative humidity.

[0099] The measurement is carried out immediately after crosslinking.

[0100] The result obtained is shown as a percentage in Table 2. Measurement of the modulus at 100% elongation of the adhesive joint (obtained at the initial time) :

[0101] The tensile test described above is repeated with the same tensile testing machine and the same standard specimen, obtained by crosslinking the mastic composition under the same conditions.

[0102] The modulus at 100% elongation obtained is indicated in MPa in Table 2. Measurements of elongation at break and modulus at 100% elongation after temperature storage of the adhesive seal :

[0103] The above measurements are repeated on a putty composition which, after crosslinking, is exposed to a temperature of 130°C for 1 week.

[0104] The results obtained are shown in Table 2. Examples 1 and 2 (according to the invention) :

[0105] We repeat example A with the compositions of examples 1 and 2 listed in Table 1.

[0106] The results obtained, shown in Table 2, clearly show that the elongation at break of the adhesive joint of examples 1 and 2 which was stored for 1 week at 130°C is significantly better maintained compared to that measured immediately after curing, compared to the reference composition A. The same is true for the modulus at 100% elongation.

[0107] In particular, the values ​​measured after one week of storage at 130 °C of the adhesive seal, for elongation at break and modulus at 100% elongation, are acceptable for examples 1 and 2, whereas they are not for reference example A. Example B (comparative) :

[0108] We repeat example A with the composition of example B listed in Table 1, which is in accordance with the teaching of international application WO 2018 / 215463.

[0109] The result obtained, shown in Table 2, shows a significant degradation in both the elongation at break and the modulus at 100% elongation of the adhesive joint, resulting from its storage for one week at 130°C, compared to the compositions of examples 1 and 2.

[0110] In particular, the values ​​measured after one week of storage at 130 °C of the adhesive seal, for elongation at break and modulus at 100% elongation, are not acceptable. [Table 1] Ingredients Content (as a percentage by weight) Ex. A (ref.) Ex. 1 Ex. 2 Ex. B (comp.) (A) GENIOSIL ®< STP-E35 15,97 15,00 15,00 15,00 MS POLYMER ™< S227 7,00 7,00 7,00 7,00 (B) MIKHART ®< 1T 49,70 49,70 49,70 49,70 (C) DOWSIL ®< 3055 - 0,97 - - DOWSIL ®< 0217 - - 0,97 - DC 3074 ®< - - - 0,97 (D) SILQUEST ®< A-1120 0,49 0,49 0,49 0,49 DBU 0,10 0,10 0,10 0,10 MESAMOLL ®< 19,28 19,28 19,28 19,28 KRONOS ®< 2059 1,98 1,98 1,98 1,98 VTMO 1,48 1,48 1,48 1,48 TINUVIN ®< T770 0,25 0,25 0,25 0,25 TINUVIN ®< 328 0,25 0,25 0,25 0,25 CRAYVALLAC SLX 3,50 3,50 3,50 3,50 [Table 2] Measured property for the adhesive seal Ex. A (ref.) Ex. 1 Ex. 2 Ex. B (comp.) immediately after crosslinking Elongation at break (in %) 580 740 650 630 Modulus at 100% elongation (in MPa) 0,75 0,5 0,57 0,55 after one week of storage at 130°C Elongation at break (in %) 20 400 210 65 Modulus at 100% elongation (in MPa) 0 0,48 0,4 0,15

Claims

1. A sealant composition comprising: - from 3% to 80% of a polymer (A) comprising an alkoxysilane group, - at least 25% of a carbonate filler (B), and - from 0.5% to 20% of a polysiloxane resin (C) comprising, as groups directly linked to the silicon atom: - at least one phenyl group; and - at least one group chosen from a hydroxyl and an aminoalkylene group of formula: -R'0- NH-R"0, wherein: - R'0 is an alkylene radical comprising from 2 to 5 carbon atoms; and - R"0 is a hydrogen atom or an alkyl radical comprising from 1 to 5 carbon atoms; and - from 0.1% to 1% of a crosslinking catalyst (D); said percentages being expressed by weight on the basis of the total weight of said composition.

2. The sealant composition as claimed in claim 1, characterized in that the polymer (A) comprising an alkoxysilane group comprises at least one, preferably at least two, groups of formula (I): [Chem 13]         -Si(R4)p(OR5)3-p     (I) wherein: - R4 and R5, which may be identical or different, each represent a linear or branched alkyl radical comprising from 1 to 4 carbon atoms; and - p is an integer equal to 0, 1 or 2.

3. The sealant composition as claimed in claim 2, characterized in that the polymer (A) comprising an alkoxysilane group is chosen from the polymers of formulae (II), (III) or (IV): [Chem 14]         (R5O)3-p(R4)pSi - R0 - [OR2]n - R0 - Si(R4)p(OR5)3-p     (II) wherein: - R0 represents a linear or branched divalent alkylene radical comprising from 3 to 6 carbon atoms; - R1 represents a divalent hydrocarbon-based radical comprising from 5 to 15 carbon atoms which can be aromatic or aliphatic and linear, branched or cyclic; - R2 represents a linear or branched divalent alkylene radical comprising from 2 to 4 carbon atoms; - R3 represents a linear or branched divalent alkylene radical comprising from 1 to 6 carbon atoms; - R6 represents a hydrogen atom, a phenyl radical, a linear, branched or cyclic alkyl radical comprising from 1 to 6 carbon atoms, or a 2-succinate radical of formula: wherein R7 is a linear or branched alkyl radical comprising from 1 to 6 carbon atoms; - n is an integer such that the number-average molecular weight of the polyether block of formula -[OR2]n- ranges from 300 g / mol to 40 000 g / mol in the polymers of formulae (II), (III) and (IV); - m1 is zero or an integer; - n and m1 are such that the number-average molecular weight of the polymer of formula (III) ranges from 500 g / mol to 50 000 g / mol; - m is an integer other than zero; - n and m are such that the number-average molecular weight of the polymer of formula (IV) ranges from 500 g / mol to 50 000 g / mol.

4. The sealant composition as claimed in one of claims 1 to 3, characterized in that the carbonate filler is chosen from alkali metal or alkaline-earth metal carbonates and mixtures thereof; preferably, the carbonate filler is calcium carbonate.

5. The sealant composition as claimed in one of claims 1 to 4, characterized in that the polysiloxane resin (C) comprises an aminoalkylene group of formula: -R'0- NH-R"0; wherein R'0 is an alkylene radical comprising from 2 to 3 carbon atoms and R"0 is a hydrogen atom.

6. The sealant composition as claimed in one of claims 1 to 5, characterized in that the polysiloxane resin (C) is a silsesquioxane.

7. The sealant composition as claimed in claim 6, characterized in that the silsesquioxane (C) corresponds to general formula (V): wherein each one from among R'1 to R'8 represents, independently of one another, a group chosen from: - a hydrogen atom, - a hydroxyl group or the aminoalkylene group of formula: -R'0- NH-R"0; - a radical chosen from the group consisting of a linear or branched C1-C4 alkoxy radical, a linear or branched alkyl radical comprising from 1 to 30 carbon atoms, an alkenyl radical comprising from 2 to 30 carbon atoms, an aromatic radical comprising from 6 to 30 carbon atoms, an allyl radical comprising from 3 to 30 carbon atoms, a cyclic aliphatic radical comprising from 3 to 30 carbon atoms and an acyl radical comprising from 1 to 30 carbon atoms, and - an -OSiR'9R'10 group wherein R'9 and R'10 each represent, independently of one other, a hydrogen atom or a radical chosen from the group consisting of a linear or branched C1-C4 alkyl, a linear or branched C1-C4 alkoxy, a C2-C4 alkenyl, a phenyl, a C3-C6 allyl radical, a cyclic C3-C8 aliphatic radical and a C1-C4 acyl radical; on condition that: - at least one radical among the R'1 to R'8 radicals is a phenyl radical; and - at least one radical among the R'1 to R'8 radicals is either a hydroxyl group or the aminoalkylene group of formula: -R'0- NH-R"0-.

8. The sealant composition as claimed in one of claims 1 to 7, characterized in that the polysiloxane resin (C) has a number-average molecular weight ranging from 400 g / mol to 4000 g / mol.

9. The sealant composition as claimed in one of claims 1 to 8, characterized in that it comprises, in addition to the ingredients (A), (B), (C) and (D), from 0.5% to 30% by weight of at least one additive chosen from plasticizers, solvents, pigments, adhesion promoters, moisture absorbers, UV stabilizers, rheological agents, and also fillers other than the carbonate fillers.

10. The sealant composition as claimed in one of claims 1 to 9, characterized in that it comprises from: - 10% to 50% by weight of polymer (A) comprising an alkoxysilane group; - 25% to 80% by weight of carbonate filler (B); - 0.5% to 5% by weight of polysiloxane resin (C); - 0.2% to 0.8% by weight of crosslinking catalyst (D); and - 0.5% to 30% of an additive chosen from plasticizers, solvents, pigments, adhesion promoters, moisture absorbers, UV stabilizers, rheological agents and also fillers other than the carbonate fillers.

11. The sealant composition as claimed in one of claims 1 to 10, characterized in that it comprises from: - 20% to 30% by weight of polymer (A) comprising an alkoxysilane group; - 40% to 60% by weight of carbonate filler (B); - 0.5% to 1.5% by weight of polysiloxane resin (C); - 0.2% to 0.8% by weight of crosslinking catalyst (D); and - 10% to 30% of an additive chosen from plasticizers, solvents, pigments, adhesion promoters, moisture absorbers, UV stabilizers, rheological agents and also fillers other than the carbonate fillers.

12. The use of the composition as defined in one of claims 1 to 11, as adhesive, sealant or coating.