THERMALLY ACCELERATED ADHESIVE COMPOSITIONS BASED ON SILANE-TERMINATED POLYMERS

Description

[0001] The present invention relates to a reactive one-component adhesive composition which is liquid at room temperature and, based on the total weight of the composition, contains 3 wt.% to 90 wt.% of at least one alpha-silane-terminated organic polymer, 0 wt.% to 80 wt.% of at least one silicone resin, 0.1 wt.% to 5 wt.% of at least one thermal accelerator, wherein the at least one thermal accelerator is a salt of a bicyclic tertiary amine of the following formula (II): where n is an integer from 1 to 3, 0.001 wt.% to 5 wt.% of at least one low-molecular-weight silane containing a primary or secondary amino group or a blocked amino group that hydrolyzes to the primary or secondary amino group, the low-molecular-weight silane having a molecular weight in the range of 100 to 500 g / mol, and 0 wt.% to 85 wt.% of at least one filler. The invention further relates to a method for bonding two substrates using this adhesive composition and to a system bonded in this way.

[0002] Thermoaccelerated reactive adhesives are widely used in industrial applications to meet the requirements of a relatively long curing time, often due to process-related reasons, and relatively rapid curing, thus enabling further processing (e.g., sawing). Typical applications include the manufacture of insulation panels with metal facings. Curing takes place in a heated press, which accelerates the chemical curing process. Since many applications involve bonding substrates with significantly different coefficients of expansion, the pressing temperature must not be too high to prevent the bond from warping. Thermolabile accelerators are used in 2-component polyurethane adhesives, such as those available from the Tosoh Corporation under the trade name Toyocat®.

[0003] The isocyanate component of these adhesives is typically based on (polymeric) methylenediphenyl diisocyanate (MDI). The use of monomeric MDI has recently been restricted under REACH due to its sensitizing effects, as reflected in the restriction proposals of the European Chemicals Agency.

[0004] Two-component adhesives are typically processed using a mixing and dispensing system, whereby the specified mixing ratio must always be maintained throughout the process. Deviations from the specified mixing ratio can result in quality defects. Typical application methods are spraying or beading using a rake. Spraying creates a spray mist that can be released into the environment and must therefore be considered in occupational health and safety. When applying a bead using a rake, the reactive mixture can accumulate in the rake over time, causing it to clog. This effect is particularly pronounced when the rake and adhesive are poorly matched.

[0005] Alternatively, moisture-curing 1-component polyurethane adhesives are used. The disadvantage of this process, however, is that CO2 is formed during curing, which must be removed during the pressing process. If the pressing time is shortened or the moisture content is too low, so-called post-expansion is possible, which can lead to defects or reduced strength in the bond.

[0006] Silane-based hot melt adhesives are described in the German patent application with the application number 102020111278.5.

[0007] Another requirement in the manufacture of panels used, for example, in buildings, ships, or railways is fire protection. An adhesive used in these exemplary areas and meeting Class A2 according to DIN EN 13501:2019-05 may have a maximum calorific value of 4 MJ / m² with reference to an internal non-substantial component of a construction product according to EN ISO 1716 (2018-10). Flame-resistant polyurethane adhesives with low calorific values ​​of less than 15 MJ / kg are described, for example, in WO 03 / 051954 A1.

[0008] Another application area in which liquid reactive adhesives are subjected to a thermal curing process is the production of headliners in the automotive sector or the manufacture of panels. US Pat. No. 5,007,976 A describes a process in which a sandwich composite consisting of a foam core, glass fiber, and fabric cover layer is pressed at temperatures above 90°C using an MDI-based 1K polyurethane adhesive. One object of the present invention is to provide a thermally accelerating adhesive composition that is isocyanate-free, does not evolve gas during curing, is a single-component adhesive, and advantageously has a comparatively low calorific value.

[0009] EP3494188B1 discloses a crosslinkable coating composition containing a silane-functional polymer, a silicone resin, an aminosilane and DBU.

[0010] The object is achieved by a reactive one-component adhesive composition which is liquid at room temperature, based on the total weight of the composition containing a) 3 wt.% to 90 wt.% of at least one alpha-silane-terminated organic polymer; b) 0 wt.% to 80 wt.% of at least one silicone resin; c) 0.1 wt.% to 5 wt.% of at least one thermal accelerator, wherein the at least one thermal accelerator is a salt of a bicyclic tertiary amine of the following formula (II): wherein n is an integer from 1 to 3; d) 0.001 wt.% to 5 wt.% of at least one low molecular weight silane having a primary or secondary amino group or a blocked amino group that hydrolyzes to the primary or secondary amino group, wherein the low molecular weight silane has a molecular weight in the range of 100 to 500 g / mol; e) 0 wt.% to 85 wt.% of at least one filler.

[0011] The object is also achieved by a method for bonding two substrates, comprising the steps (a) applying a reactive one-component adhesive composition according to the invention to a first substrate to produce an adhesive surface, (b) bringing a second substrate into contact with the adhesive surface from step (a) and (c) thermally curing the adhesive composition, preferably at a temperature of at least 50°C.

[0012] The object is also achieved by a bonded substrate system comprising two substrates, wherein the two substrates have a common adhesive surface by means of which the two substrates are bonded with the aid of a thermocured adhesive composition according to the invention, in particular according to the method according to the invention.

[0013] Surprisingly, it has been shown that the bonding of two substrates, particularly for the production of sandwich elements, using the adhesive composition according to the invention meets industrial cycle times. The adhesive composition according to the invention is characterized by its ease of processing, its broad adhesion spectrum, and its low-odor curing in many applications, particularly in the automotive and construction sectors, where existing solvent- or isocyanate-containing adhesives (e.g., sealants, flooring adhesives, assembly adhesives) must be replaced. The rapid curing enables many industrial applications. Accordingly, the present invention also relates to the use of an adhesive composition according to the invention in the automotive and construction sectors.

[0014] It has further surprisingly been found that the problem can be solved satisfactorily with a mixture containing so-called alpha-silanes (α-silanes) and optionally silicone resins, as described in WO 2003 / 014 226 A1, WO 2010 / 066 826 A1 or WO 2013 / 026 654 A1, in combination with a thermolabile accelerator, as described in DE 60 116 825 T2, in the presence of a low molecular weight silane and optionally fillers and further additives.

[0015] Thus, a headliner for motor vehicles can be produced using a common method for bonding two substrates. Accordingly, a further aspect of the present invention relates to the method according to the invention for bonding two substrates, wherein the resulting bonded substrate system represents a headliner for motor vehicles. Accordingly, substrate systems according to the invention can be headliners for motor vehicles.

[0016] The reactive one-component adhesive composition according to the invention thus differs from two-component adhesives and surface coatings. Furthermore, the reactive one-component adhesive composition according to the invention is liquid at room temperature, which distinguishes it from hot melt adhesives, which are solid at room temperature. Within the scope of the present invention, the term "liquid" is considered to be distinct from "solid." In any case, a maximum viscosity of 1000 Pa*s at 20 rpm, 25°C (Brookfield method) should not be exceeded.

[0017] The reactive one-component adhesive composition according to the invention is preferably free of monomeric isocyanates. For the purposes of the present invention, "free of monomeric isocyanates" means a proportion of less than 1 wt.% based on the total amount of the composition. Preferably, the proportion is <0.1 wt.%.

[0018] Preferably, the reactive one-component adhesive composition according to the invention contains, based on the total weight of the composition: a) 3 wt.% to 90 wt.% of the at least one alpha-silane-terminated organic polymer; b) 0 wt.% to 50 wt.% of the at least one silicone resin; c) 0.1 wt.% to 5 wt.% of the at least one thermal accelerator; d) 0.001 wt.% to 5 wt.% of the at least one low molecular weight silane having a primary or secondary amino group or a blocked amino group that hydrolyzes to the primary or secondary amino group; e) 0 wt.% to 80 wt.% of the at least one filler.

[0019] More preferably, the reactive one-component adhesive composition according to the invention contains, based on the total weight of the composition: a) 3 wt.% to 50 wt.% of the at least one alpha-silane-terminated organic polymer; b) 1 wt.% to 30 wt.% of the at least one silicone resin; c) 0.1 wt.% to 2.5 wt.% of the at least one thermal accelerator; d) 0.01 wt.% to 5 wt.% of the at least one low molecular weight silane having a primary or secondary amino group or a blocked amino group that hydrolyzes to the primary or secondary amino group; e) 10 wt.% to 80 wt.% of the at least one filler.

[0020] More preferably, the reactive one-component adhesive composition according to the invention contains, based on the total weight of the composition: a) 5 wt.% to 25 wt.% of the at least one alpha-silane-terminated organic polymer; b) 5 wt.% to 20 wt.% of the at least one silicone resin; c) 0.1 wt.% to 1 wt.% of the at least one thermal accelerator; d) 0.1 wt.% to 4 wt.% of the at least one low molecular weight silane having a primary or secondary amino group or a blocked amino group that hydrolyzes to the primary or secondary amino group; e) 30 wt.% to 80 wt.% of the at least one filler.

[0021] More preferably, the reactive one-component adhesive composition according to the invention contains, based on the total weight of the composition: a) 15 wt.% to 25 wt.% of the at least one alpha-silane-terminated organic polymer; b) 10 wt.% to 12 wt.% of the at least one silicone resin; c) 0.2 wt.% to 0.5 wt.% of the at least one thermal accelerator; d) 1 wt.% to 3 wt.% of the at least one low molecular weight silane having a primary or secondary amino group or a blocked amino group that hydrolyzes to the primary or secondary amino group; e) 59.5 wt.% to 73.8 wt.% of the at least one filler.

[0022] The reactive one-component adhesive composition according to the invention contains components a) to e), with components b) and e) being optional (0 wt.%). Accordingly, the reactive one-component adhesive composition according to the invention contains components a), c), d) or components a), b) with ≥ 0.1 wt.%, c), d) or components a), c), d), e) with ≥ 0.1 wt.%, or components a), b) with ≥ 0.1 wt.%, c), d) and e) with ≥ 0.1 wt.%.

[0023] In addition, the composition according to the invention may comprise further components. Accordingly, one embodiment of the present invention relates to a reactive one-component adhesive composition according to the invention, which consists of the components listed above. Another embodiment of the present invention relates to a reactive one-component adhesive composition according to the invention, which, in addition to the components listed above, further comprises one or more components, such as two, three, four, five, six, seven, eight, nine, or ten.

[0024] The reactive one-component adhesive composition according to the invention contains at least one alpha-silane-terminated organic polymer. Accordingly, the reactive one-component adhesive composition according to the invention can comprise one alpha-silane-terminated polymer or several, such as two, three, or four, polymers. It is clear to the person skilled in the art that polymers are not pure substances, but rather, due to their production, occur as a mixture of substances with a characteristic material distribution, and that "a polymer" therefore simply refers to this mixture of substances.

[0025] Alpha-silane-terminated organic polymers are known to those skilled in the art and can be obtained commercially, for example. Wacker Chemie AG, Munich (Germany), markets such alpha-silane-modified polymers under the name Geniosil ®<, such as Geniosil ®< STP-E10 or Geniosil ®< XB 502.

[0026] Alpha-silanes are characterized by the so-called alpha effect. In this effect, the proximity of an electronegative donor, such as nitrogen or oxygen, in the alpha position to the silicon atom, i.e., separated from it only by a methylene bridge, for example, causes the activation of alkoxy groups on the silicon atom. These groups are therefore more reactive toward nucleophiles, such as water. This, in turn, causes accelerated hydrolysis without the need for tin-containing catalysts, for example. The hydrolysis of the silanes can occur with crosslinking to form siloxanes. In this respect, the reactive one-component adhesive compositions according to the invention represent alpha-silane-terminated adhesives that can react with moisture to form siloxanes.

[0027] Preferably, the at least one alpha-silane-terminated organic polymer is an alpha-silane-terminated organic polymer of the formula (I) Y-[(CR 1a< 2 )-Si(R 2a< ) b1 (OR 3a< ) 3-b1 ] x (I), where Y represents an x-valent polymer radical bonded via nitrogen, oxygen or sulfur, R 2a< may be the same or different and represents a monovalent, optionally substituted, SiC-bonded hydrocarbon radical, R 1a< may be the same or different and represents a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical which may be bonded to the carbon atom via nitrogen, phosphorus, oxygen, sulfur or carbonyl group, R 3a< may be the same or different and represents a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical, x is an integer from 1 to 10, b1 may be the same or different and is 0, 1 or 2.

[0028] Such alpha-silane-terminated organic polymers are known from WO 2003 / 014 226 A1, WO 2010 / 066 826 A1 or WO 2013 / 026 654 A1.

[0029] Accordingly, examples of radicals R 2a< are alkyl radicals, such as methyl, ethyl, n-propyl, iso-propyl, 1-n-butyl, 2-n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, neo-pentyl, tert-pentyl radical; hexyl radicals, such as n-hexyl radical; heptyl radicals, such as n-heptyl radical; octyl radicals, such as n-octyl, iso-octyl radicals and 2,2,4-trimethylpentyl radical; nonyl radicals, such as n-nonyl radical; decyl radicals, such as n-decyl radical; dodecyl radicals, such as n-dodecyl radical; octadecyl radicals, such as n-octadecyl radical; Cycloalkyl radicals, such as cyclopentyl, cyclohexyl, cycloheptyl, and methylcyclohexyl; alkenyl radicals, such as vinyl, 1-propenyl, and 2-propenyl; aryl radicals, such as phenyl, naphthyl, anthryl, and phenanthryl; alkaryl radicals, such as o-, m-, p-tolyl, xylyl, and ethylphenyl; and aralkyl radicals, such as benzyl, alpha-, and beta-phenylethyl.Examples of substituted radicals R 2a< are haloalkyl radicals such as the 3,3,3-trifluoro-n-propyl radical, the 2,2,2,2',2',2'-hexafluoroisopropyl radical, and the heptafluoroisopropyl radical, and haloaryl radicals such as the o-, m-, and p-chlorophenyl radicals. The radical R 2a< is preferably a monovalent hydrocarbon radical having 1 to 6 carbon atoms, optionally substituted by halogen atoms, particularly preferably an alkyl radical having 1 or 2 carbon atoms, in particular the methyl radical.

[0030] Examples of radicals R 1a< are a hydrogen atom, the radicals indicated for R 2a<, and optionally substituted hydrocarbon radicals bonded to the carbon atom via nitrogen, phosphorus, oxygen, sulfur, carbon, or a carbonyl group. The radical R 1a< is preferably a hydrogen atom and hydrocarbon radicals having 1 to 20 carbon atoms, in particular a hydrogen atom.

[0031] Examples of radicals R 3a< are a hydrogen atom or the examples given for radical R 2a<. The radical R 3a< is preferably a hydrogen atom or an optionally halogen-substituted alkyl radical having 1 to 10 carbon atoms, particularly preferably an alkyl radical having 1 to 4 carbon atoms, in particular the methyl and ethyl radicals.

[0032] For the purposes of the present invention, polymers on which the polymer radical Y is based are understood to mean all polymers in which at least 50%, preferably at least 70%, particularly preferably at least 90%, of all bonds in the main chain are carbon-carbon, carbon-nitrogen or carbon-oxygen bonds.Polymer radical Y is preferably an organic polymer radical which, as a polymer chain, is polyoxyalkylene, such as polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer and polyoxypropylene-polyoxybutylene copolymer; hydrocarbon polymers such as polyisobutylene, polyethylene or polypropylene and copolymers of polyisobutylene with isoprene; polyisoprenes; polyurethanes; polyesters; polyamides; polyacrylates; Contain polymethacrylates and polycarbonates and which are preferably linked to the group or via -OC(=O)-NH-, -NH-C(=O)-O-, -NH-C(=O)-NH-, -NR'-C(=O)-NH-, NH-C(=O)-NR' -, -NH-C(=O)-, -C(=O)-NH-, -C(=O)-O-, -OC{=O)-, -OC(=O)-O-, -SC(=O)-NH- , -NH-C(=O)-S-, -C(=O)-S-, -SC{=O)-, -SC(=O)-S-, -C(-O)-, -S-, -O- and -NR'-Groups -[(CR 1a< 2 )-Si(R 2a< ) b1 (OR 3a< ) 3-b1 ] are bonded, where R' can be the same or different and has a meaning given for R 2a< or stands for a group -CH(COOR")-CH 2 -C(O)OR", in which R" can be the same or different and has a meaning given for R 2a<. Examples of radicals R' are cyclohexyl, cyclopentyl, n- and iso-propyl, n-, iso- and t-butyl, the various stereoisomers of the pentyl radical, hexyl radical or heptyl radical and the phenyl radical. The radical R' is preferably a group -CH(COOR")-CH 2 -COOR" or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, particularly preferably a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms or an alkoxy group having 6 to 20 carbon atoms optionally substituted by halogen atoms.The radicals R" are preferably alkyl groups having 1 to 10 carbon atoms, particularly preferably methyl, ethyl or propyl radicals.

[0033] Particularly preferably, radical Y in formula (I) is a polyurethane radical and a polyoxyalkylene radical, in particular a polyoxypropylene-containing polyurethane radical or a polyoxypropylene radical.

[0034] In a particularly preferred embodiment of the invention, at least one alpha-silane-terminated organic polymer is a silane-terminated polyether and a silane-terminated polyurethane, in particular a silane-terminated polypropylene glycol and a silane-terminated polyurethane, each having dimethoxymethylsilyl, trimethoxysilyl, diethoxymethylsilyl or triethoxysilyl end groups attached via -OC(=O)-NH-C(R 1a< ) 2 groups or -NH-C (=O)-NR'-C(R 1a< ) 2 groups, where R' and R 1a< have one of the meanings given above.

[0035] The average molecular weights Mn of the alpha-silane-terminated organic polymers are preferably at least 400 g / mol, more preferably at least 600 g / mol, in particular at least 800 g / mol, and preferably at most 30,000 g / mol, more preferably at most 19,000 g / mol, in particular at most 13,000 g / mol. The viscosity is preferably at least 0.2 Pas, preferably at least 1 Pas, more preferably at least 5 Pas, and preferably at most 1,000 Pas, preferably at most 700 Pas, each measured at 20°C.

[0036] The alpha-silane-terminated organic polymers used in the invention are commercially available products or can be prepared by methods commonly used in chemistry. The alpha-silane-terminated organic polymers can be prepared by various known methods, such as addition reactions, such as hydrosilylation, Michael addition, Diels-Alder addition, or reactions between isocyanate-functional compounds and compounds containing isocyanate-reactive groups.

[0037] Most preferably, the at least one alpha-silane-terminated organic polymer is a polymer which has at least one end group, preferably at least two and in particular a plurality of end groups of the formula *-XC(=O)-N(R)-C(R 1< R 2< )-Si(R 3< ) a (OR 4< ) 3-a wherein X is O or N(R); each R independently represents hydrogen or a hydrocarbon radical having 1 to 20 carbon atoms; R 1< and R 2< independently represent hydrogen or a hydrocarbon radical having 1 to 20 carbon atoms; R 3< and R 4< independently represent a hydrocarbon radical having 1 to 20 carbon atoms; a represents 0, 1 or 2 and "*" indicates the bond for attachment to the polymer.

[0038] More preferably, R is hydrogen or an alkyl radical having 1 to 4 carbon atoms, where the alkyl radical may be straight-chain or branched. Even more preferably, R is H, methyl, or ethyl, and even more preferably hydrogen or methyl.

[0039] Particularly preferably, R is hydrogen.

[0040] More preferably, R 1< and R 2< are identical. Even more preferably, R 1< and R 2< are hydrogen or an alkyl radical having 1 to 4 carbon atoms, where the alkyl radical may be straight-chain or branched. Even more preferably, R 1< and R 2< are H, methyl, or ethyl, even more preferably hydrogen or methyl.

[0041] Particularly preferably, R 1< and R 2< are hydrogen.

[0042] More preferably, R 3< and R 4< are identical. Further more preferably, R 3< and R 4< are an alkyl radical having 1 to 4 carbon atoms, where the alkyl radical may be straight-chain or branched. Even more preferably, R 3< and R 4< are methyl or ethyl.

[0043] Particularly preferred are R 3< and R 4< methyl.

[0044] Preferably, a = 0 or 1, more preferably a = 1.

[0045] An exemplary at least one alpha-silane-terminated organic polymer is a polymer having at least one end group of the formula *-OC(=O)-NH-CH 2 -Si(CH 3 )(OCH 3 ) 2 .

[0046] The organic polymer is preferably a polyoxyalkylene, a hydrocarbon polymer, a polyurethane, a polyester, a polyamide, a polysiloxane, a polyacrylate, a polymethacrylate, or a polycarbonate. Polyoxyalkylene is preferred. The organic polymer preferably contains no additional silane groups beyond the end groups listed above.

[0047] Preferred polyoxyalkylenes are polypropylenes, for example having a number-average molecular weight in the range from 5000 g / mol to 50,000 g / mol, more preferably from 7500 g / mol to 30,000 g / mol, more preferably from 10,000 g / mol to 15,000 g / mol.

[0048] The reactive one-component adhesive composition according to the invention may further contain at least one silicone resin. Thus, one or more, such as two, three, or four, different silicone resins may be present. Only one silicone resin is preferred. These silicone resins are different from the alpha-silane-terminated organic polymers that are classified as component a).

[0049] A phenylsilicone resin is preferred. Silicone resins are described, for example, in DE 10 2013 213 835 A1. A silicone resin is considered an additional component in the context of the present invention, unless it is already one of the components described above.

[0050] Accordingly, possible silicone resins according to DE 10 2013 213 835 A1 contain units of the formula R 3'< c' (R 4'< O) d' R 5'< e' SiO (4-c'-d'-e') / 2 (II), where R 3'< can be the same or different and represents a hydrogen atom, a monovalent, SiC-bonded, optionally substituted aliphatic hydrocarbon radical or a divalent, optionally substituted, aliphatic hydrocarbon radical bridging two units of the formula (II), R 4'< can be the same or different and represents a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical, R 5'< can be the same or different and represents a monovalent, SiC-bonded, optionally substituted aromatic hydrocarbon radical, c' is 0, 1, 2 or 3, d' is 0, 1, 2 or 3, preferably 0, 1 or 2, particularly preferably 0 or 1, and e' is 0, 1 or 2, preferably 0 or 1, with the proviso that the sum of c' + d' + e' is less than or equal to 3, in at least one unit e' is other than 0 and in at least 40% of the units of formula (II) the sum c' + e' is equal to 0 or 1.

[0051] Suitable silicone resins preferably consist of at least 90% by weight of units of formula (II), particularly preferably exclusively of units of formula (II).

[0052] Examples of radicals R 3'< are alkyl radicals, such as methyl, ethyl, n-propyl, iso-propyl, 1-n-butyl, 2-n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, neo-pentyl, tert-pentyl radical; hexyl radicals, such as n-hexyl radical; heptyl radicals, such as n-heptyl radical; octyl radicals, such as n-octyl, iso-octyl radicals and 2,2,4-trimethylpentyl radical; nonyl radicals, such as n-nonyl radical; decyl radicals, such as n-decyl radical; dodecyl radicals, such as n-dodecyl radical; octadecyl radicals, such as n-octadecyl radical; Cycloalkyl radicals, such as the cyclopentyl, cyclohexyl, cycloheptyl radicals and methylcyclohexyl radicals; alkenyl radicals, such as the vinyl, 1-propenyl and 2-propenyl radicals; aryl radicals, such as the phenyl, naphthyl, anthryl and phenanthryl radicals; alkaryl radicals, such as o-, m-, p-tolyl radicals; xylyl radicals and ethylphenyl radicals; and aralkyl radicals, such as the benzyl radical, the o- and the β-phenylethyl radical.

[0053] Examples of substituted radicals R 3'< are haloalkyl radicals, such as the 3,3,3-trifluoro-n-propyl radical, the 2, 2,2,2',2',2'-hexafluoroisopropyl radical and the heptafluoroisopropyl radical, and haloaryl radicals, such as the o-, m- and p-chlorophenyl radical.

[0054] The radical R 3'< preferably comprises a monovalent hydrocarbon radical having 1 to 6 carbon atoms, optionally substituted by halogen atoms, particularly preferably an alkyl radical having 1 or 2 carbon atoms, in particular the methyl radical. However, the radical R 3'< can also be a divalent aliphatic radical that links two silyl groups of the formula (II), such as alkylene radicals having 1 to 10 carbon atoms, such as methylene, ethylene, propylene, or butylene radicals.

[0055] However, the radical R 3'< is preferably a monovalent SiC-bonded aliphatic hydrocarbon radical having 1 to 18 carbon atoms, optionally substituted by halogen atoms, particularly preferably an aliphatic hydrocarbon radical having 1 to 6 carbon atoms, in particular the methyl radical.

[0056] Examples of radical R 4'< are hydrogen atom or the examples given for radical R 3'<.

[0057] The radical R 4'< is preferably a hydrogen atom or an alkyl radical having 1 to 10 carbon atoms which is optionally substituted by halogen atoms, particularly preferably an alkyl radical having 1 to 4 carbon atoms, in particular the methyl and ethyl radical.

[0058] Examples of radicals R 5'< are the aromatic radicals given above for R 3'<.

[0059] The radical R 5'< is preferably SiC-bonded aromatic hydrocarbon radicals having 1 to 18 carbon atoms, optionally substituted by halogen atoms, such as ethylphenyl, toluyl, xylyl, chlorophenyl, naphthyl or styryl radicals, particularly preferably the phenyl radical.

[0060] Preference is given to using silicone resins in which at least 90% of all radicals R 3'< are methyl, at least 90% of all radicals R 4'< are methyl, ethyl, propyl or isopropyl and at least 90% of all radicals R 5'< are phenyl.

[0061] Preference is given to silicone resins which comprise at least 40%, particularly preferably at least 60%, of units of formula (II) in which c' is 0, in each case based on the total number of units of formula (II).

[0062] Preferably, silicone resins are used which, based on the total number of units of formula (II), comprise at least 70%, particularly preferably at least 80%, of units of formula (II) in which d' is 0 or 1.

[0063] Preference is given to using silicone resins which, based on the total number of units of formula (II), comprise at least 20%, particularly preferably at least 40%, of units of formula (II) in which e' is 1. Silicone resins may be used which comprise exclusively units of formula (II) in which e' is 1, but particularly preferably at least 10%, particularly preferably at least 20%, at most 60%, and particularly preferably at most 80% of the units of formula (II) have an e' of 0.

[0064] Preferably, silicone resins are used which, based in each case on the total number of units of formula (II), have at least 50%, particularly preferably at least 70%, in particular at least 80%, units of formula (II) in which the sum c' + e' is equal to 1.

[0065] In a particularly preferred embodiment of the invention, silicone resins are used which, based on the total number of units of formula (II), comprise at least 20%, particularly preferably at least 40%, of units of formula (II) in which e' is 1 and c' is 0. Preferably, at most 40%, particularly preferably at most 70%, of all units of formula (II) have a d' not equal to 0.

[0066] In a further particularly preferred embodiment of the invention, silicone resins are used which, in each case based on the total number of units of the formula (II), have at least 20%, particularly preferably at least 40%, of units of the formula (II) in which e' is 1 and c' is 0 and which additionally have at least 1%, preferably at least 10%, of units of the formula (II) in which c' is 1 or 2, preferably 1, and e' is 0.

[0067] Examples of silicone resins are organopolysiloxane resins which consist essentially, preferably exclusively, of (Q) units of the formulas SiO 4 / 2 , Si(OR 4'< )O 3 / 2 , Si(OR 4'< ) 2 O 2 / 2 and Si(OR 4'< ) 3 O 1 / 2 , (T) units of the formulas PhSiO 3 / 2 , PhSi(OR 4'< )O 2 / 2 , PhSi(OR 4'< ) 2 O 1 / 2 , MeSiO 3 / 2 , MeSi(OR 4'< )O 2 / 2 and MeSi(OR 4'< ) 2 O 1 / 2 (D) units of the formulas Me 2 SiO 2 / 2 , Me 2 Si(OR 4'< )O 1 / 2 , Ph 2 SiO 2 / 2 and Ph 2 Si(OR 4'< )O 1 / 2 , MePhSiO 2 / 2 and MePhSi(OR 4'< )O 1 / 2 and (M) units of the formula Me 3 SiO 1 / 2 , where Me is a methyl radical, Ph is a phenyl radical and R 4'< is a hydrogen atom or an alkyl radical optionally substituted by halogen atoms and having 1 to 10 carbon atoms, particularly preferably a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms, the resin containing 0-2 mol of (Q) units, 0-2 mol of (D) units and 0-2 mol of (M) units per mol of (T) units.

[0068] Preferred examples of silicone resins are organopolysiloxane resins which consist essentially, preferably exclusively, of T units of the formulas PhSiO 3 / 2 , PhSi(OR 4'< )O 2 / 2 and PhSi(OR 4'< ) 2 O 1 / 2 , T units of the formulas MeSiO 3 / 2 , MeSi(OR 4'< )O 2 / 2 and MeSi(OR 4'< ) 2 O 1 / 2 and D units of the formulas Me 2 SiO 2 / 2 and Me 2 Si(OR 4'< )O 1 / 2 , where Me is a methyl radical, Ph is a phenyl radical and R 4'< is a hydrogen atom or optionally substituted by halogen atoms alkyl radicals having 1 to 10 carbon atoms, particularly preferably hydrogen atom or alkyl radicals having 1 to 4 carbon atoms, with a molar ratio of (T) to (D) units from 0.5 to 2.0.

[0069] Among these examples, silicone resins are particularly preferred whose units of the formula (II) are formed to at least 50%, preferably at least 70%, in particular at least 85% from T units of the formulas PhSiO 3 / 2 , PhSi(OR 4'< )O 2 / 2 , PhSi(OR 4'< ) 2 O 1 / 2 , MeSiO 3 / 2 , MeSi(OR 4'< )O 2 / 2 and MeSi(OR 4'< ) 2 O 1 / 2 , wherein these silicone resins contain at least 30%, preferably at least 40%, in particular at least 50% T units of the formulas PhSiO 3 / 2 , PhSi(OR 4'< )O 2 / 2 and PhSi(OR 4'< ) 2 O 1 / 2 and at least 10%, preferably at least 15%, in particular at least 20% T units of the MeSiO 3 / 2 , MeSi(OR 4'< )O 2 / 2 and MeSi(OR 4'< ) 2 O 1 / 2 .

[0070] The silicone resins preferably have an average molecular weight (number average) Mn of at least 500 g / mol, particularly preferably at least 600 g / mol. The average molecular weight Mn is preferably at most 400,000 g / mol, particularly preferably at most 100,000 g / mol, in particular at most 50,000 g / mol.

[0071] Such silicone resins can be either solid or liquid at 23°C and 1000 hPa, with silicone resins preferably being liquid.

[0072] The silicone resins are commercially available products (e.g. Silres ®< IC 368 from Wacker Chemie (DE)) or they can be manufactured using methods commonly used in silicon chemistry.

[0073] Furthermore, the reactive one-component adhesive composition according to the invention contains at least one thermal accelerator. Accordingly, it may contain one thermal accelerator. It may also contain several, such as two, three, or four, thermal accelerators.

[0074] Thermoaccelerators are described in the prior art, for example in DE 60 116 825 T2.

[0075] According to the invention, the at least one thermal accelerator is a salt of a bicyclic tertiary amine of the following formula (II): wherein n is an integer from 1 to 3. Particularly preferably, the at least one thermal accelerator is DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or a salt thereof.

[0076] According to the invention, a salt of the bicyclic tertiary amine is used, in particular a salt of the bicyclic tertiary amine with an aliphatic monocarboxylic acid, wherein the monocarboxylic acid is preferably selected from the group consisting of methacrylic acid, crotonic acid and tiglic acid, wherein the mixing ratio is preferably adjusted such that the molar ratio of the bicyclic tertiary amine to the aliphatic monocarboxylic acid is at most 1.3.

[0077] In particular, the crotonic acid salt of DBU is preferred.

[0078] Furthermore, the reactive one-component adhesive composition according to the invention contains at least one low-molecular-weight silane containing a primary or secondary, preferably a primary, amino group or a blocked amino group that hydrolyzes to the primary or secondary amino group. Thus, component d) can contain one or more, such as two, three, or four, such silanes. Component d) preferably consists of only one component. Component d) is different from components a) to c) and only counts as component d) to the extent that it cannot be considered one of components a) to c).

[0079] The at least one low molecular weight silane of component d) has a primary amino group -NH 2 . The amino group can be part of a functional group, such as an amide group -C(=O)NH 2 or a primary amine in the narrower sense. Advantageously, it is an amine. Low molecular weight silanes that have a secondary amino group can also be used. Blocked aminosilanes can also be used. In this case, the blocked amino group hydrolyzes to the primary or secondary amino group, preferably to the primary amino group. An example is ((triethoxysilyl)propyl)methylisobutylimine, which is sold under the trade name VPS 1262 by Evonik (DE). Here, too, the amino group can be part of a functional group or it is an amino group, which is preferred.Of course, several primary amino groups can be present, in particular several primary amino groups, several secondary amino groups, and at least one primary and at least one secondary amino group. Instead of the primary or secondary amino group, the blocked form can of course be used. However, a primary or secondary amino group is preferred, and more preferably a primary amino group.

[0080] The low molecular weight silanes have a molecular weight in the range of 100 g / mol to 500 g / mol.

[0081] Preferred low molecular weight silanes are described in DE 10 2012 200790 A1. Accordingly, preferred low molecular weight silanes are those containing units of the formula DSi(OR 7'< ) g' R 8'< (3-g') (IX), wherein R 7'< can be the same or different and represents a hydrogen atom or optionally substituted hydrocarbon radicals, D can be the same or different and represents a monovalent, SiC-bonded radical with basic nitrogen of a primary, secondary or blocked amino group, R 8'< can be the same or different and represents a monovalent, optionally substituted, SiC-bonded organic radical free of basic nitrogen, g' is 1, 2 or 3, preferably 2 or 3.

[0082] Examples of optionally substituted hydrocarbon radicals R 7'< are the examples given below for radical R 3'<.

[0083] The radicals R 7'< are preferably hydrogen atoms and optionally halogen-substituted hydrocarbon radicals having 1 to 18 carbon atoms, particularly preferably hydrogen atoms and hydrocarbon radicals having 1 to 10 carbon atoms, in particular methyl and ethyl radicals.

[0084] Examples of radical R 8'< are the examples given for R 3'< below.

[0085] The radical R 8'< is preferably a hydrocarbon radical having 1 to 18 carbon atoms, optionally substituted by halogen atoms, particularly preferably a hydrocarbon radical having 1 to 5 carbon atoms, in particular the methyl radical. Examples of radicals D are radicals of the formulas H 2 N(CH 2 ) 3 -, H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -, H 2 N(CH 2 ) 2 NH(CH 2 ) 2 NH(CH 2 ) 3 -, H 3 CNH(CH 2 ) 3 -, C 2 H 5 NH(CH 2 ) 3 -, C 3 H 7 NH(CH 2 ) 3 -, C 4 H 9 NH(CH 2 ) 3 -, C 5 H 11 NH(CH 2 ) 3 -, C 6 H 13 NH(CH 2 ) 3 -, C 7 H 15 NH(CH 2 ) 3 -, H 2 N(CH 2 ) 4 -, H 2 N-CH 2 -CH(CH 3 )-CH 2 -, H 2 N(CH 2 ) 5 -, cyclo-C 5 H 9 NH(CH 2 ) 3 -, cyclo-C 6 H 11 NH(CH 2 ) 3 -, phenyl-NH(CH 2 ) 3 -, (CH 3 ) 2 N(CH 2 ) 3 -, (C 2 H 5 ) 2 N(CH 2 ) 3 -, (C 3 H 7 ) 2 NH(CH 2 ) 3 -, (C 4 H 9 ) 2 NH(CH 2 ) 3 -, (C 5 R 11 ) 2 NH(CH 2 ) 3 -, (C 6 H 13 ) 2 NH(CH 2 ) 3 -, (C 7 H 15 ) 2 NH(CH 2 ) 3 -, H 2 N(CH 2 )-, H 2 N(CH 2 ) 2 NH(CH 2 )-, H 2 N(CH 2 ) 2 NH(CH 2 ) 2 NH(CH 2 )-, H 3 CNH(CH 2 )-,C 2 H 5 NH(CH 2 )-, C 3 H 7 NH(CH 2 )-, C 4 H 9 NH(CH 2 )-, C 5 H 11 NH(CH 2 )-, C 6 H 13 NH(CH 2 )-, C 7 H 15 NH(CH 2 )-, cyclo-C 5 H 9 NH(CH 2 )-, cyclo-C 6 H 11 NH(CH 2 )-, phenyl-NH(CH 2 )-, (CH 3 ) 2 N(CH 2 )-, (C 2 H 5 ) 2 N(CH 2 )-, (C 3 H 7 ) 2 NH(CH 2 )-, (C 4 H 9 ) 2 NH(CH 2 )-, (C5H11) 2 NH(CH 2 )-, (C 6 H 13 ) 2 NH(CH 2 )-, (C 7 H 15 ) 2 NH(CH 2 )-, (CH 3 O) 3 Si(CH 2 ) 3 NH(CH 2 ) 3 -, (C 2 H 5 O) 3 Si(CH 2 ) 3 NH(CH 2 ) 3 -, (CH 3 O) 2 (CH 3 )Si(CH 2 ) 3 NH(CH 2 ) 3 - and (C 2 H 5 O) 2 (CH 3 )Si(CH 2 ) 3 NH(CH 2 ) 3 - as well as reaction products of the above-mentioned primary amino groups with compounds which contain double bonds or epoxide groups which are reactive towards primary amino groups (blocked amino groups).

[0086] Beispiele für die Silane der Formel (IX) sind H 2 N(CH 2 ) 3 -Si(OCH 3 ) 3 , H 2 N(CH 2 ) 3 -Si(OC 2 H 5 ) 3 , H 2 N(CH 2 ) 3 -Si(OCH 3 ) 2 CH 3 , H 2 N(CH 2 ) 3 -Si(OC 2 H 5 ) 2 CH 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OCH 3 ) 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OC 2 H 5 ) 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OCH 3 ) 2 CH 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OC 2 H 5 ) 2 CH 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OH) 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OH) 2 CH 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 2 NH(CH 2 ) 3 Si-(OCH 3 ) 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 2 NH(CH 2 ) 3 -Si(OC 2 H 5 ) 3 , cyclo-C 6 H 11 NH(CH 2 ) 3 Si-(OCH 3 ) 3 , cyclo-C 6 H 11 NH(CH 2 ) 3 -Si(OC 2 H 5 ) 3 , cyclo-C 6 H 11 NH(CH 2 ) 3 -Si(OCH 3 ) 2 CH 3 , cyclo-C 6 H 11 NH(CH 2 ) 3 -Si(OC 2 H 5 ) 2 CH 3 , cyclo-C 6 H 11 NH(CH 2 ) 3 -Si(OH) 3 , cyclo-C 6 H 11 NH(CH 2 ) 3 -Si(OH) 2 CH 3 , Phenyl-NH(CH 2 ) 3 -Si(OCH 3 ) 3 , Phenyl-NH(CH 2 ) 3 -Si(OC 2 H 5 ) 3 , Phenyl-NH(CH 2 ) 3 -Si(OCH 3 ) 2 CH 3 ,Phenyl-NH(CH 2 ) 3 -Si(OH) 3 , Phenyl-NH(CH 2 ) 3 -Si(OH) 2 CH 3 , HN((CH 2 ) 3 -Si(OCH 3 ) 3 ) 2 , HN((CH 2 ) 3 -Si(OC 2 H 5 ) 3 ) 2 HN((CH 2 ) 3 -Si(OCH 3 ) 2 CH 3 ) 2 , HN((CH 2 ) 3 -Si(OC 2 H 5 ) 2 CH 3 ) 2 , cyclo-C 6 H 11 NH(CH 2 )-Si(OCH 3 ) 3 , cyclo-C 6 H 11 NH(CH 2 )-Si(OC 2 H 5 ) 3 , cyclo-C 6 H 11 NH(CH 2 )-Si(OCH 3 )2CH 3 , cyclo-C 6 H 11 NH(CH 2 )-Si(OC 2 H 5 ) 2 CH 3 , cyclo-C 6 H 11 NH(CH 2 )-Si(OH) 3 , cyclo-C 6 H 11 NH(CH 2 )-Si(OH) 2 CH 3 , Phenyl-NH(CH 2 )-Si(OCH 3 ) 3 , Phenyl-NH(CH 2 )-Si(OC 2 H 5 ) 3 , Phenyl-NH(CH 2 )-Si(OCH 3 ) 2 CH 3 , Phenyl-NH(CH 2 )-Si(OC 2 H 5 ) 2 CH 3 , Phenyl-NH(CH 2 )-Si(OH) 3 und Phenyl-NH(CH 2 )-Si(OH) 2 PM 3 sowie deren Teilhydrolysate, wobei H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OCH 3 ) 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OC 2 H 5 ) 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OCH 3 ) 2 CH 3 , cyclo-C 6 H 11 NH(CH 2 ) 3 -Si(OCH 3 ) 3 ,cyclo-C 6 H 11 NH(CH 2 ) 3 -Si(OC 2 H 5 ) 3 and cyclo-C 6 H 11 NH(CH 2 ) 3 -Si(OCH 3 ) 2 CH 3 and their partial hydrolysates are preferred and H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OCH 3 ) 3 , H 2 N(CH 2 ) 2 NH(CH 2 ) 3 -Si(OCH 3 ) 2 CH 3 , cyclo-C 6 H 11 NH(CH 2 ) 3 -Si(OCH 3 ) 3 , cyclo-C 6 H 11 NH(CH 2 ) 3 -Si(OCH 3 ) 2 CH 3 and their partial hydrolysates are particularly preferred.

[0087] Particularly preferred examples are also N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyldimethoxysilane, or 3-ureidopropyltrimethoxysilane. 3-aminopropyltrimethoxysilane is particularly preferred.

[0088] Furthermore, the reactive one-component adhesive composition according to the invention may additionally contain at least one filler. Examples of fillers are calcium carbonate, for example chalk, or corundum, such as high-grade corundum.

[0089] The reactive one-component adhesive composition according to the invention allows for high filler levels, which can be advantageous in various applications. Examples include applications that require good thermal conductivity or special fire performance requirements.

[0090] Sandwich elements, for example, can be produced using the reactive one-component adhesive composition according to the invention. It has been shown that formulations in which a thermal accelerator is used in the reactive one-component adhesive composition according to the invention can be processed at room temperature for several minutes and can result in short pressing times when heated from approximately 60°C. The use of amines as catalysts is described, for example, in WO 2019 / 004922 A1 for two-component coatings. Toyocat® DB 40, a commercially available product, is a blocked amine and is mentioned, for example, in DE 10 2016 200 704 A1.

[0091] The reactive one-component adhesive composition according to the invention may also contain a water scavenger, such as vinyltrimethoxysilane.

[0092] To reduce the PCS value (heat of combustion), the reactive one-component adhesive composition according to the invention can contain the above-mentioned fillers, such as chalk. A low calorific value can be promoted by the use of at least one silicone resin.

[0093] During the curing of the reactive one-component adhesive composition according to the invention, methanol is split off by a condensation reaction with the formation of siloxane groups.

[0094] In the process according to the invention, the reactive one-component adhesive composition according to the invention can be applied to the substrate by conventional methods, e.g., by notched trowel, bead, spray, or slotted nozzle application, optionally sprayed with water, and then pressed, for example, at temperatures of at least 60°C. The reactive one-component adhesive composition according to the invention is particularly suitable for the production of headliners in the automotive sector or for the production of panels. The reactive one-component adhesive composition according to the invention is particularly suitable for sandwich elements, in which aluminum panels are used in particular. Mineral wool panels, particularly with stainless steel cover layers, are also suitable within the scope of the present invention.

[0095] Accordingly, the present invention also relates to a method according to the invention for bonding two substrates, resulting in a bonded substrate system, as well as to a substrate system according to the invention, wherein the substrate system is a headliner in the automotive sector or panels. Furthermore, the substrate system can preferably be sandwich elements, in which aluminum panels are used in particular. Preferred panels are mineral wool panels, especially with stainless steel cover layers.

[0096] Furthermore, the present invention is particularly well suited for aluminum or stainless steel panels that are difficult to bond, but is also very well suited, for example, for painted or unpainted sheet steel cover layers that are easy to bond.

[0097] Accordingly, the present invention also relates to a method according to the invention for bonding two substrates, wherein a bonded substrate system is obtained, as well as to a substrate system according to the invention, wherein at least the first or the second substrate is an aluminum or stainless steel plate or a painted or unpainted steel sheet cover layer.

[0098] Surprisingly, after just a few minutes, strengths are achieved that largely correspond to the level of industrially used 1K or 2K polyurethane adhesives. Examples

[0099] Example 1 for an adhesive formulation according to the invention:

[0100] 180 g of Geniosil STP-E10, 120 g of Silres 368, and 15 g of Dynasylan VTMO were placed in a planetary mixer equipped with a butterfly stirrer. Then, 700 g of CALCIT MX 30 were added in portions and stirred until the fillers were well dispersed. The mixture was stirred at room temperature under vacuum (50 mbar) for 30 minutes. A further 15 g of vinyltrimethoxysilane, 4 g of accelerator from DE60116825T2, Example 3 (mixture of DBU and crotonic acid), and 20 g of Geniosil GF95 were added, and the mixture was stirred for a further 5 minutes under vacuum (50 mbar) (see Table 1). Table 1: Raw materials used and their mass balance. raw material Manufacturer Crowd g Portion % by weight SILRES 368, silicone resin b) Brave 120 11,4 GENIOSIL STP-E10, α-Silane term. polymer a) Brave 180 17,1 CALCIT MX 30, filler e) SH MINERALS GMBH 700 66,4 GENIOSIL GF 95, Aminosilane d) Brave 20 1,9 Accelerator (DE60116825T2, Example 3), c) - 4 0,4 Dynasylan VTMO, water scavenger Evonik 30 2,8

[0101] The physicochemical properties of the resulting formulation are listed in Table 2. Table 2: Physical and chemical properties at 23 °C. parameter Value Unit Viscosity at 6.8 s -1< 44000 mPa*s density 1,7 g / m 2 Skin formation time*) approx. 8 minutes *) The skin formation time is determined by pressing and then lifting a wooden spatula into the adhesive bead at 23 °C and 50% relative humidity. This process is repeated every 60 seconds until the adhesive no longer wets the wooden spatula.

[0102] Application example 1 for a process according to the invention (production of a roof lining for motor vehicles): Approximately 100 g / m² of the adhesive from the above inventive example 1 is applied to a rigid foam and sprayed with approximately 35 g / m² of water. The resulting composite, consisting of an additional glass fiber mat and a fabric, is pressed at 120°C for 40 seconds. After the pressing time, the strength of the adhesive in a manual peel test is slightly higher than the inherent strength of the foam, with the adhesive penetrating the entire composite.

[0103] Application example 2 for a process according to the invention (production of mineral wool panels): Approximately 400 g / m² of the adhesive from the above example is applied to a (coated) metal sheet using a notched trowel, sprayed with approximately 100 g of water, and mineral wool with a density of approximately 110 kg / m³ is inserted so that the mineral wool fibers are perpendicular to the sheet. The composite is pressed for 3.5 or 4.5 minutes at 60°C. The composite was manually torn open immediately after the pressing time, which resulted in a significant amount of fiber tearout.

[0104] Compared to the reactive polyurethane adhesives used in the current state of the art, this invention represents an isocyanate-free alternative. The strength build-up is comparable to polyurethane adhesives. The reactive one-component adhesive composition according to the invention is particularly suitable for sandwich elements using aluminum panels. Mineral wool panels, especially those with stainless steel cover layers, are also suitable within the scope of the present invention.

[0105] Currently, two-component polyurethane adhesives are used for the production of mineral wool panels. These adhesives are mixed using low- or high-pressure machines and applied via spraying or pouring processes. These processes are quite complex, error-prone, and require investment in expensive machinery.

[0106] For the inventive reactive one-component adhesive composition according to Example 1, a heat of combustion of 7.8 MJ / kg was determined according to EN ISO 1716. This comparatively low value is due to the high filler content on the one hand and the silicone resin content on the other. This allows the production of mineral wool panels that meet Class A2 according to DIN EN 13501:2019-05 with application quantities of up to approximately 500 g / m². The inventive reactive one-component adhesive composition according to Example 1 also exhibits good heat resistance.

Claims

1. Reactive one-component adhesive composition which is liquid at room temperature, containing, based on the total weight of the composition, a) 3 wt% to 90 wt% of at least one alpha-silane-terminated organic polymer; b) 0 wt% to 80 wt% of at least one silicone resin; c) 0.1 wt% to 5 wt% of at least one thermal accelerator, the at least one thermal accelerator being a salt of a bicyclic tertiary amine of the following formula (II): in which n is an integer from 1 to 3; d) 0.001 wt% to 5 wt% of at least one low molecular weight silane which has a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group, the low molecular weight silane having a molecular weight in the range from 100 to 500 g / mol; e) 0 wt% to 85 wt% of at least one filler.

2. Reactive one-component adhesive composition according to Claim 1, characterized in that the at least one alpha-silane-terminated organic polymer has the formula (I)         Y-[(CR1a2)-Si(R2a)b1(OR3a)3-b1]x     (I), where Y is an x-valent polymer radical bonded via nitrogen, oxygen or sulfur, R2a may be identical or different and is a monovalent, optionally substituted, SiC-bonded hydrocarbon radical, R1a may be identical or different and is hydrogen atom or a monovalent, optionally substituted hydrocarbon radical which may be attached to the carbon atom via nitrogen, phosphorus, oxygen, sulfur or carbonyl group, R3a may be identical or different and is hydrogen atom or a monovalent, optionally substituted hydrocarbon radical, x is an integer from 1 to 10, b1 may be identical or different and is 0, 1 or 2.

3. Reactive one-component adhesive composition according to Claim 1 or 2, characterized in that the at least one alpha-silane-terminated organic polymer has at least one end group of the formula *-X-C(=O)-N(R)-C(R1R2)-Si(R3)a(OR4)3-a, where X is O or N(R); each R independently of any other is hydrogen or a hydrocarbon radical having 1 to 20 carbon atoms; R1 and R2 independently of one another are hydrogen or a hydrocarbon radical having 1 to 20 carbon atoms; R3 and R4 independently of one another are a hydrocarbon radical having 1 to 20 carbon atoms; a is 1 or 2; and "*" marks the bond for the attachment to the polymer.

4. Reactive one-component adhesive composition according to any of Claims 1 to 3, characterized in that the at least one organic polymer is a polyoxyalkylene, a hydrocarbon polymer, a polyurethane, a polyester, a polyamide, a polysiloxane, a polyacrylate, a polymethacrylate or a polycarbonate.

5. Reactive one-component adhesive composition according to any of Claims 1 to 4, characterized in that the at least one organic polymer is a polyoxyalkylene.

6. Reactive one-component adhesive composition according to any of Claims 1 to 5, characterized in that the at least one silicone resin is a phenyl silicone resin.

7. Reactive one-component adhesive composition according to any of Claims 1 to 6, characterized in that the salt of the bicyclic tertiary amine is a salt with an aliphatic monocarboxylic acid, where the monocarboxylic acid is preferably selected from the group consisting of methacrylic acid, crotonic acid and tiglic acid, where the mixing ratio is established preferably such that the molar ratio of the bicyclic tertiary amine to the aliphatic monocarboxylic acid is at most 1.3.

8. Reactive one-component adhesive composition according to any of Claims 1 to 7, characterized in that the salt is a salt of DBU.

9. Reactive one-component adhesive composition according to any of Claims 1 to 8, characterized in that the at least one thermal accelerator is a crotonic acid salt of DBU.

10. Reactive one-component adhesive composition according to any of Claims 1 to 9, characterized in that it contains, based on the total weight of the composition: a) 3 wt% to 90 wt% of the at least one alpha-silane-terminated organic polymer; b) 0 wt% to 50 wt% of the at least one silicone resin; c) 0.1 wt% to 5 wt% of the at least one thermal accelerator; d) 0.001 wt% to 5 wt% of the at least one low molecular weight silane which has a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group; e) 0 wt% to 80 wt% of the at least one filler.

11. Reactive one-component adhesive composition according to any of Claims 1 to 10, characterized in that it contains, based on the total weight of the composition: a) 3 wt% to 50 wt% of the at least one alpha-silane-terminated organic polymer; b) 1 wt% to 30 wt% of the at least one silicone resin; c) 0.1 wt% to 2.5 wt% of the at least one thermal accelerator; d) 0.01 wt% to 5 wt% of the at least one low molecular weight silane which has a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group; e) 10 wt% to 80 wt% of the at least one filler.

12. Reactive one-component adhesive composition according to any of Claims 1 to 11, characterized in that it contains, based on the total weight of the composition: a) 5 wt% to 25 wt% of the at least one alpha-silane-terminated organic polymer; b) 5 wt% to 20 wt% of the at least one silicone resin; c) 0.1 wt% to 1 wt% of the at least one thermal accelerator; d) 0.1 wt% to 4 wt% of the at least one low molecular weight silane which has a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group; e) 30 wt% to 80 wt% of the at least one filler.

13. Reactive one-component adhesive composition according to any of Claims 1 to 12, characterized in that it contains, based on the total weight of the composition: a) 15 wt% to 25 wt% of the at least one alpha-silane-terminated organic polymer; b) 10 wt% to 12 wt% of the at least one silicone resin; c) 0.2 wt% to 0.5 wt% of the at least one thermal accelerator; d) 1 wt% to 3 wt% of the at least one low molecular weight silane which has a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group; e) 59.5 wt% to 73.8 wt% of the at least one filler.

14. Method for bonding two substrates, containing the steps of (a) applying a reactive one-component adhesive composition according to any of Claims 1 to 13 to a first substrate, to give an adhesive area, (b) contacting a second substrate with the adhesive area from step (a), and (c) thermally curing the adhesive composition, preferably at a temperature of at least 50°C.

15. Bonded substrate system composed of two substrates, where the two substrates have a common adhesive area via which the two substrates are bonded using a thermally cured adhesive composition according to any of Claims 1 to 13.