Reactive hot melt adhesive compositions based on alpha-silane terminated organic polymers

Abstract

The present invention relates to a reactive hot melt adhesive composition comprising, based on the total weight of the composition, a) 3% to 49% by weight of at least one alpha-silane terminated organic polymer, b) 1% to less than 20% by weight, preferably 1% to 10% by weight of at least one acrylate resin-based polymer, c) 1% to 20% by weight, preferably 1% to 10% by weight of at least one chemical that is liquid at least at 100° C. and in which the at least one acrylate resin-based polymer is soluble at least at 150° C., and d) 0.001% to 5% by weight, preferably 0.001% to 2% by weight of at least one oligomeric silane containing one or more amino groups. The present invention also relates to processes for their preparation and to processes for laminating surfaces using the compositions.

Description

[Technical Field]

[0001] The present invention relates to reactive hot melt adhesive compositions. The invention also relates to processes for their production and to processes for surface lamination using the compositions. [Background technology]

[0002] Reactive hot melt adhesives have a large market share and are widely used due to advantages such as short curing times, high early strength, and stability, and have replaced solvent-based adhesives in many applications (e.g., Bodo Muller, Walter Rath, Formulierung von Kleb-und Dichtstoffen [Formulation of Adhesives and Sealants], Vincentz Network; 1 st edition, December 2004).

[0003] The main representatives among reactive hot melt adhesives are moisture-crosslinking polyurethanes based on methylene diphenyl diisocyanate (MDI). The use of monomeric MDI has recently been restricted under REACH, as evidenced by EU regulation 2020 / 1149, due to its sensitizing effect.

[0004] The patent literature describes processes for producing reactive polyurethane hot melt adhesives with a low monomer content that are based on MDI (see, for example, WO 03 / 055929 A1, WO 01 / 40342 A1, WO 03 / 033562 A1, WO 03 / 006521 A1).

[0005] A process for silanizing polyurethane hot melt adhesives, representing an isocyanate-free alternative, has also been described. This process generally involves the introduction of moisture-crosslinkable di- and / or trialkoxysilane units. One possibility for production is represented by the reaction of the isocyanate groups of a reactive polyurethane hot melt adhesive with a secondary aminosilane (e.g., WO 2004 / 005420 A1). The crosslinking reaction is generally accelerated using aminosilanes, tin accelerators, and / or strong nitrogen bases (e.g., 1,8-diazabicyclo[5.4.0]undec-7-ene). A drawback of this process is that these accelerators can simultaneously accelerate the hydrolysis of the ester units typically present in reactive polyurethane hot melt adhesives. The resulting formulations are also generally no longer stable enough to allow processing on a roll applicator. Reactive hot melt adhesives are frequently processed using a roll applicator and are often exposed to ambient humidity. Therefore, the formulation must be sufficiently stable and must not react with ambient moisture to an extent that, even during short plant shutdowns, would result in a significant increase in application weight and stringing, the latter of which would adversely affect the applied appearance.

[0006] Stable hot-melt adhesive formulations based on silane-terminated polymers constitute an interesting class of adhesives. Furthermore, such silane-functional adhesives have a broad adhesive spectrum, which may constitute an advantage compared to, for example, isocyanate-crosslinked systems. In the case of silane-terminated polymers, the silane groups are generally capable of undergoing two to three condensation reactions, allowing for a higher crosslink density compared to structurally equivalent isocyanate-based binders. In this context, it would be advantageous for these adhesives to be able to be partially processed through a hot applicator roll with reliable operation, have the high initial adhesion typical of this application, and exhibit a chemical full cure acceptable for industrial applications, among other factors.

[0007] As part of this development, two routes have been envisaged for the production of silane-based formulations: either the silanization of existing reactive PU hot melt adhesives, as explained in more detail above, where the isocyanate groups of the adhesive are chemically reacted with secondary aminosilanes, or, alternatively, commercially available silane coupling agents are formulated with crystalline or amorphous resins in order to achieve high initial adhesion.

[0008] For example, WO 2007 / 074143 A1 describes moisture-curable hot melt adhesive compositions based on silane-functionalized polyurethane prepolymers.

[0009] WO 2013 / 026654 A1 describes crosslinkable compositions based on organyloxysilane-terminated polymers. In this context, DE 10 2013 213 835 A1 describes blends of alpha-silanes, such as Geniosil® STP-E10, with silicone resins.

[0010] WO 2011 / 087741 A2 describes adhesives for binding books and related articles and the production of such adhesives from silane-modified liquid polymers. The adhesives are specifically said to have reduced or no monomeric diisocyanate content.

[0011] In both cases, the results were initially unsatisfactory: the resulting formulations either had too little initial adhesion, were not roll stable, or were too slow to fully cure.

[0012] Candidates for improving initial adhesion include polyester and polyacrylate resins. Polyester resins face the risk of hydrolytic degradation, catalyzed by typical silane adhesion promoters, such as aminosilanes. Suitable crystalline polyacrylate resins, on the other hand, must be melted at very high temperatures (approximately 150°C). However, commercially available polyether-based silane bonding agents lack stability at these temperatures. Summary of the Invention [Problem to be solved by the invention]

[0013] It was therefore an object of the present invention to provide a reactive hot melt adhesive composition which does not exhibit the above-mentioned disadvantages or at least to a lesser extent. [Means for solving the problem]

[0014] The object is to provide a reactive hot melt adhesive composition comprising, based on the total weight of the composition: a) 3% to 49% by weight of at least one alpha-silane terminated organic polymer; b) 1% to less than 20% by weight, preferably 1% to 10% by weight, of at least one acrylate resin-based polymer; c) 1% to 20% by weight, preferably 1% to 10% by weight, of at least one chemical that is liquid at least at 100°C and in which at least one acrylate resin-based polymer dissolves at least at 150°C; d) 0.001% to 5% by weight, preferably 0.001% to 2% by weight, of at least one oligomeric silane containing one or more amino groups; This was achieved by a reactive hot melt adhesive composition comprising:

[0015] The object is likewise to provide a process for producing a reactive hot melt adhesive composition according to the invention, which comprises (a) adding at least one acrylate resin-based polymer to at least one chemical that is liquid at least at 100°C and in which the at least one acrylate resin-based polymer is soluble at at least 150°C, or adding at least one acrylate resin-based polymer to a mixture containing at least one chemical at a temperature in the range of 130°C to 170°C; (b) cooling the mixture to a temperature in the range of 80°C to 120°C; (c) adding at least one alpha-silane terminated organic polymer to the cooled mixture; (d) adding at least one oligomeric silane containing one or more amino groups to obtain the reactive hot melt adhesive composition of the present invention; This was achieved through a process that included:

[0016] This object has likewise been achieved by a process for surface lamination, which comprises applying the reactive hot melt adhesive composition according to the invention to a substrate by means of an applicator roll.

[0017] The need for roll-stable adhesives at processing temperatures of 100-120°C with acceptable complete cure speeds has surprisingly been realized using binders based on silane-terminated polymers (so-called alpha-silanes). In this case, it was possible to use acrylate resin-based polymers that are liquid up to at least 100°C and soluble up to at least 150°C with at least one oligomeric silane containing one or more amino groups. In this way, it was possible to produce hydrolytically stable formulations with satisfactory initial adhesion. Furthermore, the reactive hot melt adhesive compositions of the present invention have a high crosslink density, which may be the reason for their good plasticizer stability.

[0018] The reactive hot melt adhesive composition according to the invention therefore represents a low viscosity at 100°C, mostly roll-stable, moisture-crosslinkable adhesive formulation based on alpha-silane terminated polymers that exhibit high enough initial adhesion at room temperature for surface lamination and chemically undergo complete cure fast enough. Condensation reactions during curing result in the elimination of alcohols (more specifically methanol, and possibly ethanol) with the formation of siloxane groups.

[0019] More specifically, it is known that in alpha-silanes, the majority of alkoxysilanes undergo a self-catalytic two-step condensation reaction as a result of the donor atom (e.g., nitrogen atom) located alpha to the silicon atom (alpha effect). The reactive hot-melt adhesive compositions according to the invention are accelerated by aminosilanes and operate without the use of additional cocatalysts, such as tin organyls or diazabicycloundecenes. Surprisingly, as part of the present invention, it has been found that formulations containing alpha-silanes are roll-stable for periods of about 30 to 60 minutes at 100°C without containment under conventional ambient conditions (room temperature of about 20 to 23°C, ambient humidity of about 30 to 65% rh) and undergo chemical complete cure sufficiently rapidly without the use of additional cocatalysts, despite moderate acceleration.

[0020] The present invention therefore relates to reactive hot melt adhesive compositions. The term "hot melt adhesive" in this specification generally describes an adhesive that is solid or has a high shear modulus at room temperature and is in liquid form at elevated temperatures, typically between 100°C and 120°C. Hot melt adhesives are applied in liquid form and then resolidified, so that they are again in solid form or have a high shear modulus at room temperature. A further characteristic of "reactive" hot melt adhesives is that they crosslink via a chemical reaction. This usually involves a reaction with water, e.g., atmospheric humidity, that comes into contact with the hot melt adhesive. They are therefore referred to as moisture-crosslinking. This also applies to the reactive hot-applied adhesive compositions of the present invention.

[0021] The reactive hot-applied adhesive compositions of the present invention are likewise liquid at temperatures between 100° C. and 120° C. In this case, these adhesives typically have a viscosity of between 4000 mPas and 12000 mPas. The reactive hot-applied adhesive compositions of the present invention are preferably isocyanate-free.

[0022] The reactive hot melt adhesive composition according to the present invention comprises components a) to d). The composition of the present invention may further comprise additional components. Thus, one embodiment of the present invention relates to a reactive hot melt adhesive composition consisting of components a) to d). Another embodiment of the present invention relates to a reactive hot melt adhesive composition comprising components a) to d) and one or more, for example, two, three, four, five, six, seven, eight, nine, or ten additional components.

[0023] Component a) of the reactive hot melt adhesive composition of the present invention represents at least one alpha-silane terminated organic polymer. Thus, the reactive hot melt adhesive composition according to the present invention may comprise one alpha-silane terminated polymer, or two or more such as two, three or four polymers. In this case, it is clear to the skilled person that polymers are not pure compounds, but instead occur as a mixture of compounds with a characteristic compound distribution as a result of their production, and therefore "polymer" is a simplified expression for this mixture of compounds.

[0024] Alpha-silane terminated organic polymers are known to those skilled in the art and are, for example, commercially available, for example, Wacker Chemie AG, Munich, Germany, sells such alpha-silane modified polymers under the Geniosil® brand, such as Geniosil® STP-E10 or Geniosil® XB502.

[0025] A characteristic feature of alpha silanes is the so-called alpha effect. Due to this effect, the proximity of an electronegative donor, such as nitrogen or oxygen, in the alpha position relative to the silicon atom, i.e., separated from it only by a methylene bridge, for example, has the effect of activating the alkoxy group on the silicon atom. As a result, these groups are more reactive to nucleophiles, such as water. This results in accelerated hydrolysis without the need for, for example, tin-containing catalysts. The hydrolysis of silanes can be accompanied by crosslinking to form siloxanes. Therefore, the reactive hot melt adhesive composition of the present invention represents an alpha-silane-terminated hot melt adhesive that can undergo a moisture crosslinking reaction to form siloxanes.

[0026] The at least one alpha-silane terminated organic polymer preferably has the formula *-XC(=O)-N(R)-C(R 1 R 2 )-Si(R 3 ) a (OR 4 ) 3-a (In the formula, X is O or N(R); each R is, independently of the other, hydrogen or a hydrocarbon radical having 1 to 20 carbon atoms; R 1 and R 2 are, independently of one another, hydrogen or a hydrocarbon radical having 1 to 20 carbon atoms, R 3 and R 4 are, independently of each other, hydrocarbon radicals having 1 to 20 carbon atoms, a is 0, 1 or 2; "*" indicates a bond for attachment to the polymer) It is a polymer containing multiple end groups.

[0027] More preferably, R is hydrogen or an alkyl radical containing 1 to 4 carbon atoms, which alkyl radical may be straight or branched. Even more preferably, R is H, methyl or ethyl, even more preferably hydrogen or methyl.

[0028] More specifically, R is hydrogen. More preferably, R 1 and R 2 are identical. Furthermore, R 1 and R 2 is hydrogen or an alkyl radical containing 1 to 4 carbon atoms, which alkyl radical may be linear or branched. More preferably, R 1 and R 2 is H, methyl or ethyl, more preferably hydrogen or methyl.

[0029] More particularly preferably, R 1 and R 2 is hydrogen. More preferably, R 3 and R 4 are identical. Furthermore, R 3 and R 4 is an alkyl radical containing 1 to 4 carbon atoms, and the alkyl radical (radical) may be linear or branched. More preferably, R 3 and R 4 is methyl or ethyl.

[0030] Even more preferably, R 3 and R 4 is methyl. Preferably, a is 1 or 2, and more preferably a is 1.

[0031] An exemplary at least one alpha-silane terminated organic polymer is a polymer containing multiple end groups of the formula -OC(=O)-NH-CH2-Si(CH3)(OCH3)2.

[0032] The organic polymer is terminated with a number of end groups, as described in more detail above. The organic polymer is preferably a polyoxyalkylene, a hydrocarbon polymer, a polyurethane, a polyester, a polyamide, a polyacrylate, a polymethacrylate, or a polycarbonate. Polyoxyalkylene is preferred. The organic polymer preferably does not contain any additional silane groups beyond the above end groups.

[0033] A preferred polyoxyalkylene is, for example, polypropylene having a number average molecular weight in the range of 5000 g / mol to 50,000 g / mol, more preferably 7500 g / mol to 30,000 g / mol, more preferably 10,000 g / mol to 15,000 g / mol.

[0034] Component a) has a proportion of 3 to 49% by weight, preferably 3 to 20% by weight, more preferably 5 to 20% by weight, based on the total weight of the composition.

[0035] The reactive hot melt adhesive composition according to the present invention further comprises at least one acrylate resin-based polymer as component b). Thus, the composition of the present invention may comprise one or more, for example two, three or four, acrylate-based polymers. In this case, it is clear to those skilled in the art that the polymers are not pure compounds, but instead arise as a mixture of compounds with a characteristic compound distribution as a result of their production, and therefore "polymer" is a simplified expression for this mixture of compounds. Component b) preferably comprises only one acrylate resin-based polymer.

[0036] When component a) as organic polymer is likewise an acrylate resin-based polymer, components a) and b) can be distinguished from one another in that component b) does not contain alpha-silane end groups.

[0037] The acrylate resin-based polymer is preferably a homoacrylate, a homomethacrylate, a copolymer of at least two different acrylates, a copolymer of at least two different methacrylates, or a copolymer of at least one acrylate and at least one methacrylate.

[0038] The proportion of component b) is 1 to 20% by weight, preferably 1 to 10% by weight, and more preferably 8 to 9% by weight, based on the total weight of the reactive hot melt adhesive composition of the present invention.

[0039] The purpose of component b) is to achieve sufficient initial adhesion. In this connection, copolymers of methyl methacrylate and n-butyl methacrylate are even more preferred.

[0040] The at least one acrylate resin-based polymer may be crystalline, partially crystalline, or amorphous, and therefore has a melting point, melting range (in which case the lower temperature is considered the melting point), or glass transition temperature. This temperature is preferably in the range of 30°C to 300°C, more preferably 30°C to 250°C, even more preferably 30°C to 150°C, even more preferably 30°C to 80°C, even more preferably 40°C to 75°C, even more preferably 50°C to 70°C, and more specifically 60°C. The at least one acrylate resin-based polymer is preferably amorphous, in which case the specified temperature value refers to its glass transition temperature.

[0041] The at least one acrylate resin-based polymer preferably has an average weight-average molar weight in the range of 10,000 g / mol to 150,000 g / mol, more preferably 25,000 g / mol to 125,000 g / mol, even more preferably 30,000 g / mol to 110,000 g / mol, even more preferably 35,000 g / mol to 100,000 g / mol, even more preferably 40,000 g / mol to 90,000 g / mol, even more preferably 45,000 g / mol to 80,000 g / mol, even more preferably 50,000 g / mol to 70,000 g / mol, and more specifically an average weight-average molar weight of 60,000 g / mol.

[0042] As component c), the reactive hot melt adhesive composition comprises at least one chemical that is liquid at at least 100°C and in which at least one acrylate resin-based polymer is soluble at at least 150°C.

[0043] In the context of this invention, "dissolves at least 150°C" refers to dissolution of the solid acrylic polymer. However, dissolution may occur at lower temperatures. If the melting point or melting range or glass transition temperature is below 150°C, "dissolves" refers to the formation of a single-phase mixture with the chemical.

[0044] Component c) may contain one chemical substance or more than one, for example, two, three, or four chemical substances. Advantageously, it contains only one compound. Component c) is different from components a) or b). Thus, a compound is considered to be component c) if it is in liquid form at least up to 100°C and is capable of dissolving component b) at least at 150°C within the range of possible proportions as a proportion of the total composition, as long as it is different from components a) and b).

[0045] The proportion of component c) is 1 to 20% by weight, based on the total weight of the reactive hot-apply adhesive composition of the present invention. The proportion is preferably 1 to 10% by weight. More preferably, the proportion is 6% by weight.

[0046] The only important factor for a chemical, apart from its dissolving power, is that it exists as a liquid at least at 100°C. Many compounds can be used, and those skilled in the art can find suitable compounds by simple solubility tests. Below is a list of exemplary compounds that can be used:

[0047] The at least one chemical that is liquid at at least 100° C. and in which the at least one acrylate resin-based polymer dissolves at at least 150° C. may advantageously be a plasticizer.

[0048] Exemplary plasticizers are known in the art, and in this connection reference may be made to the examples listed in DIN EN ISO 1043-3 (2017-03).

[0049] Thus, examples of plasticizers are:

[0050] [Table 1] TIFF2024539682000002.tif207151

[0051] Such plasticizers are commercially available. An illustrative example is Hexamoll® DINCH from BASF SE (Ludwigshafen, Germany). Diisononyl 1,2-cyclohexanedicarboxylate or isodecyl benzoate are preferred.

[0052] The at least one chemical substance that is liquid at least at 100°C and dissolves the at least one acrylate resin-based polymer at least at 150°C can be a polyalkylene glycol. Preferred polyalkylene glycols are polyethylene glycol and polypropylene glycol, more preferably polypropylene glycol. The polyalkylene glycol preferably has a number average molecular weight in the range of 500 g / mol to 5000 g / mol, more preferably in the range of 750 g / mol to 4000 g / mol, more preferably in the range of 1000 g / mol to 3000 g / mol, and more specifically, a number average molecular weight of 2000 g / mol.

[0053] The at least one chemical substance that is liquid at least at 100°C and dissolves at least one acrylate resin-based polymer at least at 150°C can be an alkoxysilane. Alkoxysilanes are commercially available. An example that can be given is that manufactured by Evonik Industries AG, Essen (Germany) under the trade name Tegopac®. This is a bonding agent that pendantly crosslinks ethoxysilane.

[0054] The reactive hot melt adhesive composition of the present invention additionally comprises component d) containing at least one oligomeric silane containing one or more amino groups. Thus, component d) can contain one or more such silanes, for example, two, three, or four. Preferably, component d) consists of only one component. Component d) is considered to be component d) only if it is different from components a) to c) and therefore cannot be interpreted as one of components a) to c).

[0055] The at least one oligomeric silane containing one or more amino groups of component d) preferably constitutes a mixture of amino-group-containing alkoxy- / hydroxy-silanes and / or silanols and condensation products and co-condensation products based thereon, and preferably has a molecular weight of more than 500 g / mol.

[0056] Such oligomeric silanes containing one or more amino groups are commercially available, for example, from Evonik under the trade name Dynasylan® 1146. They are described, for example, in DE 10 2007 040 802 A1. Their preparation can therefore be described as follows:

[0057] As already observed above, at least one oligomeric silane containing one or more amino groups (A) General formula I NR'2[(CH2)2NR'] x -Y-Si(R'') n( OR) 3-n (I), in which the groups R, R' and R'' are identical or different and each represent a hydrogen atom or a linear or branched alkyl group having 1 to 8 C atoms, and Y is a divalent alkylene group from the series -CH2-, -(CH2)2-, -(CH2)3- or -[CH2CH(CH3)CH2]-, x is 0, 1 or 2, and n is 0 or 1, or (B) General formula II (RO) 3-m (R'') m Si-Y-[NR'(CH2)2] y NR'[(CH2)2NR'] z -Y-Si(R'') n (OR) 3-n (II), at least one bissilylated alkylamine of the formula (wherein the groups R, R' and R'' are identical or different and each is a hydrogen atom or a linear or branched alkyl group having 1 to 8 C atoms, the groups Y are identical or different and Y is a divalent alkylene group from the series -CH2-, -(CH2)2-, -(CH2)3- or -[CH2CH(CH3)CH2]-, y and z are independently 0, 1 or 2, and m and n are independently 0 or 1), or (C) General formula III N[-Y-Si(R'') n (OR) 3-n ]3(III), at least one tris-silylated alkylamine of the formula (wherein the groups R and R″ are identical or different and each is a hydrogen atom or a linear or branched alkyl group having 1 to 8 C atoms, Y is independently a divalent alkylene group from the series —CH—, —(CH)—, —(CH)— or —[CHCH(CH)CH]—, and n is independently 0 or 1, or (D) A mixture obtainable by subjecting at least two of the above silylated alkylamines of general formulas I, II and III to hydrolysis and condensation or co-condensation together with a specified amount of water and optionally with the addition of an acid, and then substantially removing free alcohol from the system.

[0058] Monosilylated amines here are intended to mean those of formula I. Oligosilylated amines are intended to mean in particular those which have two or more silyl groups on the amino group or, for example, on an alkylamine of formula II (bissilylated) or formula III (trissilylated), and / or corresponding compounds which may exist in cyclized form.

[0059] The mixture is prepared using an aminoalkylalkoxysilane of general formula I, which is preferably H2N(CH2)3Si(OCH3)3(AMMO), H2N(CH2)3Si(OC2H5)3(AMEO), H2N(CH2)2NH(CH2)3Si(OCH3)3(DAMO), H2N(CH2)2NH(CH2)2NH(CH2)3Si(OCH3)3(TRIAMO), and optionally the corresponding so-called cyclic compounds.

[0060] Compounds of formula II include: (H3CO)3Si(CH2)3NH(CH2)3Si(OCH3)3(Bis-AMMO), (H5C2O)3Si(CH2)3NH(CH2)3Si(OC2H5)3(Bis-AMEO), (H3CO)3Si(CH2)3NH(CH2)2NH(CH2)2NH(CH2)3Si(OCH3)3(Bis-DAMO), (H3CO)3Si(CH2)3NH(CH2)2NH(CH2)2NH(CH2)2NH(CH2)2NH(CH2)3Si(OCH3)3(Bis-TRIAMO), is preferred, and the compound of formula III is N[CH2)3Si(OCH3)3]3(Tris-AMMO), N[CH2)3Si(OC2H5)3]3(Tris-AMEO) is preferred.

[0061] Therefore, for the preparation of the mixture, it is preferable to select at least one component (A) from the series AMMO, AMEO, DAMO, TRIAMO, 3-(N-alkylamino)propyltrialkoxysilane, where alkyl is methyl, ethyl, n-propyl or n-butyl, and alkoxy is methoxy or ethoxy. A preferred selection of component (B) may be made from the series Bis-AMMO, Bis-AMEO, Bis-DAMO, and a preferred selection of component (C) may be made from the series Tris-AMMO, Tris-AMEO.

[0062] To prepare the mixture, it is also possible to advantageously use a mixture containing compounds of general formula I, II, and / or III. Such mixtures may also contain so-called partial condensation products of the aminoalkoxysilanes. By partial condensation or reaction products of aminoalkoxysilanes of general formula I, II, and / or III, we mean, appropriately, dimeric, trimeric, tetrameric, or higher oligomeric products formed by condensation or co-condensation and / or prehydrolysis of the respective monomers, typically with the elimination of alcohol. Thus, in such condensates or co-condensates, the reactant components are linked via Si-O-Si bonds. It is further known that during hydrolysis or alcoholysis, the ring system opens, yielding the corresponding aminoalkylalkoxysilanes or -silanols. The compounds of general formula II may also exist in cyclic or bicyclic form and may be used as such.

[0063] The reaction products are understood chemically to essentially comprise a mixture of amino-containing alkoxy- / hydroxy-silanes and / or silanols, as well as condensation and co-condensation products based thereon (corresponding linear, branched, cyclic and optionally three-dimensionally crosslinked siloxanes) derived from compounds of general formula I, II or III and / or corresponding partial condensation products.

[0064] When preparing the mixture, the reaction, more specifically the hydrolysis and condensation or co-condensation, is preferably carried out at a temperature of less than 100°C, preferably 10 to 80°C, more preferably 15 to 60°C, and more specifically 20 to 50°C.

[0065] When preparing the mixture, an organic or inorganic acid may optionally be used. It is therefore possible to advantageously use hydrochloric acid (HCl or aqueous hydrogen chloride), or aqueous acetic acid, or aqueous formic acid, and the resulting amount of water introduced should be counted as part of the amount of water introduced according to the present invention for the targeted hydrolysis of alkoxysilanes. However, after preparing the mixture, the acid may be added, preferably to adjust the pH to 2 to 6, more particularly 3 to 5.

[0066] The preparation of the mixture is followed in particular by work-up by distillation of the product mixture from the reaction, in other words, from the resulting product mixture, components that are otherwise volatile under ambient conditions, more particularly the hydrolysis alcohol and any added solvents or diluents, are distilled off at least proportionally, preferably under mild heating and reduced pressure. The amount of volatile components removed from the system may optionally be replaced with a volumetrically equivalent amount of water and / or acid.

[0067] The mixture may therefore preferably contain an organic or inorganic acid, and the degree of neutralization of the aminoalkyl and oligosilylated aminoalkyl groups is suitably 0 to 125%, preferably 0.1 to 120%, more preferably 70 to 115%, and very preferably 75 to 110%, based on the amine value. The determination of the amine value can generally be carried out in accordance with DIN 32 625 (potentiometric titration with HCl).

[0068] The acid used is preferably an organic or inorganic acid, more particularly hydrochloric acid, acetic acid or formic acid, and the aminoalkyl- and oligosilylated aminoalkyl-functional silicon compounds present in the composition are, according to chemical understanding, at least proportionally present in the form of a cationic amine mixture; in other words, the composition used in the present invention preferably contains an acid and / or a salt of the corresponding acid and one of the amino-functional compounds present.

[0069] The mixture may have a viscosity of 2 to 1000 mPa s, preferably 3 to 500 mPa s, more preferably 4 to 250 mPa s, the viscosity being determined, for example, according to DIN 53 015.

[0070] The proportion of component d) is 0.001 to 5% by weight, preferably 0.001 to 2% by weight, and more preferably 1.2% by weight, based on the total weight of the hot melt adhesive composition of the present invention.

[0071] In addition to components a) through d) above, the hot-apply adhesive composition of the present invention may contain additional ingredients.

[0072] The hot-applied adhesive composition of the present invention may therefore comprise at least one silicone resin, such as a phenylsilicone resin. Silicone resins are described, for example, in DE 10 2013 213 835 A1. If the silicone resin is not already one of the components specified above, it is considered an additional component in the context of the present invention.

[0073] Possible silicone resins according to DE 10 2013 213 835 A1 are therefore those of the formula R 3’ c’ (R 4’ O) d‘ R 5’ e’ SiO (4-c’-d’-e’) / 2 (II), (In the formula, R 3 ' may be the same or different and are a hydrogen atom, a monovalent SiC-bonded optionally substituted aliphatic hydrocarbon radical, or an optionally substituted divalent aliphatic hydrocarbon radical bridging two units of formula (II); R 4’ are the same or different and are hydrogen atoms or monovalent optionally substituted hydrocarbon radicals, R 5’ are the same or different monovalent SiC-bonded optionally substituted aromatic hydrocarbon radicals, c' is 0, 1, 2 or 3; d' is 0, 1, 2 or 3, preferably 0, 1 or 2, more preferably 0 or 1; e' is 0, 1 or 2, preferably 0 or 1; provided that the sum of c'+d'+e' is 3 or less, e' is other than 0 in at least one unit, and the sum of c'+e' is 0 or 1 in at least 40% of the units of formula (II).

[0074] A suitable silicone resin preferably comprises at least about 90% by weight of units of formula (II), more preferably consists solely of units of formula (II).

[0075] base R 3’ Examples of are alkyl radicals such as methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, and tert-pentyl radicals; hexyl radicals such as n-hexyl radical; heptyl radicals such as n-heptyl radical; octyl radicals such as n-octyl radical, isooctyl radical, and 2,2,4-trimethylpentyl radical; nonyl radicals such as n-nonyl radical; decyl radicals such as n-decyl radical; and dodecyl radicals such as n-dodecyl radical; cycloalkyl radicals such as cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl radicals; alkenyl radicals such as vinyl, 1-propenyl and 2-propenyl radicals; aryl radicals such as phenyl, naphthyl, anthryl and phenanthryl radicals; alkaryl radicals such as o-, m- and p-tolyl radicals; xylyl radical and ethylphenyl radical; and aralkyl radicals such as benzyl radical, o- and β-phenylethyl radicals.

[0076] Substituted Radical R 3’ Examples of 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.

[0077] Radical R 3’ preferably comprises a monovalent hydrocarbon radical having 1 to 6 carbon atoms, optionally substituted with halogen atoms, more preferably an alkyl radical having 1 or 2 carbon atoms, and more particularly a methyl radical.3’ may alternatively comprise a divalent aliphatic radical, such as an alkylene radical having 1 to 10 carbon atoms, e.g., a methylene, ethylene, propylene, or butylene radical, linking together two silyl groups of formula (II).

[0078] However, preferably, the radical R 3’ includes a monovalent SiC-bonded aliphatic hydrocarbon radical having 1 to 18 carbon atoms, which may be optionally substituted with halogen atoms, more preferably an aliphatic hydrocarbon radical having 1 to 6 carbon atoms, and more specifically a methyl radical.

[0079] Radical R 4’ Examples of are a hydrogen atom or a radical R 3’ Here is an example of a specified base R 4’ preferably comprises a hydrogen atom or an alkyl radical having 1 to 10 carbon atoms, optionally substituted with a halogen atom, more preferably an alkyl radical having 1 to 4 carbon atoms, and more particularly a methyl radical and an ethyl radical.

[0080] base R 5’ An example of this is R 3’ is an aromatic radical as specified above for base R 5’ preferably comprises a SiC-bonded aromatic hydrocarbon radical having 1 to 18 carbon atoms, optionally substituted with halogen atoms, such as an ethylphenyl, tolyl, xylyl, chlorophenyl, naphthyl or styryl radical, more preferably a phenyl radical.

[0081] All Radicals R 3’ At least 90% of the groups are methyl radicals, and all groups R 4’ at least 90% of the radicals R are methyl, ethyl, propyl or isopropyl radicals; 5’ It is preferred to use a silicone resin in which at least 90% of the radicals are phenyl radicals.

[0082] Preferred silicone resins are those which contain at least 40%, more 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).

[0083] Preferred silicone resins used comprise at least 70%, more preferably at least 80%, of units of formula (II) in which d' has a value of 0 or 1, in each case based on the total number of units of formula (II).

[0084] Preferred silicone resins used contain at least 20%, more preferably at least 40%, of units of formula (II) having a value of e' of 1, in each case based on the total number of units of formula (II). Although silicone resins containing only units of formula (II) in which e' is 1 may be used, more preferably at least 10%, more preferably at least 20%, at most 60%, more preferably at most 80% of the units of formula (II) have an e' of 0.

[0085] Preferred silicone resins used comprise at least 50%, more preferably at least 70%, and more particularly at least 80%, of units of formula (II) in which the sum c'+e' is 1, in each case based on the total number of units of formula (II).

[0086] One particularly preferred embodiment of the present invention uses a silicone resin comprising at least 20%, more preferably at least 40%, of units of formula (II) in which e' has a value of 1 and c' has a value of 0, in each case based on the total number of units of formula (II). Preferably, in this case, at most 40%, more preferably at most 70%, of all units of formula (II) have a d' other than 0.

[0087] A further particularly preferred embodiment of the present invention uses a silicone resin which comprises at least 20%, more preferably at least 40%, of units of formula (II) in which e' has a value of 1 and c' has a value of 0, and which also comprises at least 1%, preferably at least 10%, of units of formula (II) in which c' is 1 or 2, preferably 1, and e' is 0, in each case based on the total number of units of formula (II).

[0088] Examples of silicone resins include those of the formula SiO 4 / 2 , Si(OR 4’ )O 3 / 2 , Si(OR 4’ )2O 2 / 2 and Si(OR 4’ )3O 1 / 2 (Q) units, formula PhSiO 3 / 2 , PhSi(OR 4’ )O 2 / 2 , PhSi(OR 4’ )2O 1 / 2 , MeSiO 3 / 2 , MeSi(OR 4’ )O 2 / 2 and MeSi(OR 4’ )2O 1 / 2 (T) unit, formula Me2SiO 2 / 2 , Me2Si(OR 4’ )O 1 / 2 , Ph2SiO 2 / 2 and Ph2Si(OR 4’ )O 1 / 2 , MePhSiO 2 / 2 and MePhSi(OR 4’ )O 1 / 2 , (D) units of the formula Me3SiO 1 / 2 wherein Me is a methyl radical, Ph is a phenyl radical, and R 4’ is a hydrogen atom or an alkyl radical having 1 to 10 carbon atoms optionally substituted with a halogen atom, more preferably a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms, and the resin contains 0 to 2 moles of (Q) units, 0 to 2 moles of (D) units, and 0 to 2 moles of (M) units per mole of (T) units.

[0089] A preferred example of a silicone resin is of the formula PhSiO 3 / 2 , PhSi(OR 4’ )O 2 / 2 and PhSi(OR 4’ )2O 1 / 2 T unit, formula MeSiO 3 / 2 , MeSi(OR 4’ )O 2 / 2 and MeSi(OR 4’ )2O 1 / 2 T units, as well as the formula Me2SiO 2 / 2 and Me2Si(OR 4’ )O 1 / 2 wherein Me is a methyl radical, Ph is a phenyl radical, and R 4’ is a hydrogen atom or an alkyl radical having 1 to 10 carbon atoms which may be optionally substituted with a halogen atom, more preferably a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms, and the molar ratio of (T) units to (D) units is 0.5 to 2.0.

[0090] Among these examples, particularly preferred silicone resins are those in which the unit of formula (II) is represented by the formula PhSiO 3 / 2 , PhSi(OR 4’ )O 2 / 2 , PhSi(OR 4’ )2O 1 / 2 , MeSiO 3 / 2 , MeSi(OR 4’ )O 2 / 2 and MeSi(OR 4’ )2O 1 / 2 These silicone resins are formed to an extent of at least 50%, preferably at least 70%, more particularly at least 85% of the T units of the formula PhSiO 3 / 2 , PhSi(OR 4’ )O 2 / 2 and PhSi(OR 4’ )2O 1 / 2 at least 30%, preferably at least 40%, more particularly at least 50% of T units of the formula MeSiO 3 / 2, MeSi(OR 4’ )O 2 / 2 and MeSi(OR 4’ )2O 1 / 2 and the silicone resin contains at least 10%, preferably at least 15%, more particularly at least 20% of T units of the formula:

[0091] The silicone resin preferably has an average molar mass (number average) Mn of at least 500 g / mol, more preferably at least 600 g / mol. The average molar mass Mn is preferably at most 400,000 g / mol, more preferably at most 100,000 g / mol, more particularly at most 50,000 g / mol.

[0092] Such silicone resins at 23° C. and 1000 hPa may be either solid or liquid, the silicone resins being preferably liquid.

[0093] Silicone resins are commercially available products (eg Silres® IC 368 from Wacker Chemie, Germany) or they can be prepared by methods common in silicon chemistry.

[0094] Furthermore, the reactive hot melt adhesive composition according to the invention may further comprise at least one tackifying polymer (tackifier), advantageously in a proportion of 10% to 40% by weight, based on the total weight of the composition.

[0095] Furthermore, the reactive hot melt adhesive composition according to the present invention may further comprise at least one filler. Advantageously, the proportion is 10% to 40% by weight based on the total weight of the composition. Exemplary fillers are calcium carbonate, such as chalk, or α-alumina, such as high-grade α-alumina. The use of fillers can prevent or reduce stringing during processing of the adhesive composition.

[0096] The reactive hot melt adhesive compositions of the present invention can be used to achieve high levels of loading, which can be advantageous in a variety of applications. Examples that can be given here include applications that require high thermal conductivity or have specific requirements regarding fire behavior.

[0097] A further aspect of the present invention is a process for producing a reactive hot melt adhesive composition according to the present invention, said process comprising steps a) to d).

[0098] Here, in a first step (a), at least one acrylate resin-based polymer is added to at least one chemical that is liquid at at least 100°C and in which the at least one acrylate resin-based polymer dissolves at at least 150°C.

[0099] At least one acrylic polymer may also be added to the mixture containing the at least one chemical.

[0100] The addition is carried out at a temperature in the range of 130°C to 170°C, preferably in the range of 140°C to 160°C, more particularly at 150°C.

[0101] Additionally, it is possible to add a tackifying polymer in step (a). In the next step (b), the mixture is cooled to a temperature in the range of 80°C to 120°C.

[0102] This is followed by step (c) of adding at least one alpha-silane terminated organic polymer to the cooled mixture.

[0103] Finally, in step (d), at least one oligomeric silane containing one or more amino groups is added to obtain the reactive hot melt adhesive composition according to the present invention.

[0104] At least one additional filler may be added in step (c). Steps (c) and (d) are preferably carried out sequentially so that degassing can be carried out between steps.

[0105] The reactive hot melt adhesive composition of the present invention is roll stable and therefore suitable for application via a roll, and is therefore particularly suitable for processes for surface lamination in which the reactive hot melt adhesive composition according to the present invention is applied to a substrate by means of an applicator roll.

[0106] Surprisingly, it has been found that the application can be cleaned by the roll applicator even if the period of roll stability has been exceeded, i.e. if the binder during processing shows significant stringiness that defines the applied impression.

[0107] A further subject of the present invention is therefore the use of the reactive hot melt compositions according to the invention for roll applications.

[0108] The advantageous uses of the reactive hot melt adhesive compositions of the present invention result from their good adhesion, including initial adhesion. Even without roll application, the following advantageous properties are evident, as for example when used for window frame cladding. Another use is where improved thermal conductivity can be achieved. Uses related to improved fire behavior can also be mentioned.

[0109] The obvious advantages include, among others: the absence of isocyanates, -Good adhesion spectrum, especially to metals, glass and other materials -No foaming due to CO2 formation.

Claims

1. A reactive hot melt adhesive composition comprising, based on the total weight of the composition, a) 3% to 49% by weight of at least one alpha-silane terminated organic polymer; b) less than 1% to 20% by weight, preferably 1% to 10% by weight of at least one acrylate resin-based polymer; c) 1% to 20% by weight, preferably 1% to 10% by weight of at least one chemical substance that is liquid at at least 100°C and in which at least one acrylate resin-based polymer dissolves at at least 150°C; d) 0.001% to 5% by weight, preferably 0.001% to 2% by weight of at least one oligomeric silane containing one or more amino groups A reactive hot melt adhesive composition comprising.

2. wherein said at least one alpha - silane terminated organic polymer has the formula * - X - C(=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 is independently of the others hydrogen or a hydrocarbon radical having 1 to 20 carbon atoms, R １ and R ２ are, independently of one another, hydrogen or a hydrocarbon radical having from 1 to 20 carbon atoms, R ３ and R ４ are, independently of one another, hydrocarbon radicals having from 1 to 20 carbon atoms, a is 1 or 2, "*" indicates a bond for attachment to the polymer) The reactive hot melt adhesive composition according to claim 1, characterized in that it contains a large number of end groups of

3. The reactive hot melt adhesive composition according to claim 1, characterized in that the organic polymer is polyoxyalkylene, hydrocarbon polymer, polyurethane, polyester, polyamide, polyacrylate, polymethacrylate or polycarbonate.

4. The reactive hot melt adhesive composition according to claim 1, characterized in that the acrylate resin-based polymer is a homoacrylate, a homomethacrylate, a copolymer of at least two different acrylates, a copolymer of at least two different methacrylates, or a copolymer of at least one acrylate and at least one methacrylate.

5. The reactive hot melt adhesive composition according to claim 1, characterized in that the at least one chemical substance that is liquid at at least 100°C and in which the at least one acrylate resin-based polymer dissolves at at least 150°C is a plasticizer.

6. The reactive hot melt adhesive composition according to claim 1, characterized in that the at least one chemical substance that is liquid at at least 100°C and in which the at least one acrylate resin-based polymer dissolves at at least 150°C is a polyalkylene glycol.

7. The reactive hot melt adhesive composition according to claim 1, wherein the at least one chemical substance that is liquid at at least 100°C and in which the at least one acrylate resin-based polymer dissolves at at least 150°C is an alkoxysilane.

8. The reactive hot melt adhesive composition according to claim 1, wherein the at least one oligomer silane containing one or more amino groups is a mixture of an amino group-containing alkoxy- / hydroxy-silane and / or silanol, and a condensation product and a co-condensation product based thereon, and preferably has a molecular weight exceeding 500 g / mol.

9. The reactive hot melt adhesive composition according to claim 1, wherein the composition further comprises at least one tackifier polymer (tackifier) in an amount of 10% to 40% by weight based on the total weight of the composition.

10. The reactive hot melt adhesive composition according to claim 1, wherein the composition further comprises at least one filler in an amount of 10% to 40% by weight based on the total weight of the composition.

11. A process for producing the reactive hot melt adhesive composition according to any one of claims 1 to 10, (a) adding the at least one acrylate resin-based polymer to at least one chemical substance that is liquid at at least 100°C and in which the at least one acrylate resin-based polymer dissolves at at least 150°C, or adding it to a mixture containing the at least one chemical substance at a temperature in the range of 130°C to 170°C; (b) cooling the mixture to a temperature in the range of 80°C to 120°C; (c) adding at least one alpha-silane-terminated organic polymer to the cooled mixture; (d) adding at least one oligomer silane containing one or more amino groups to obtain the reactive hot melt adhesive composition according to any one of claims 1 to 10. A process comprising the above steps.

12. The process according to claim 11, wherein in step (a), a tackifier polymer is further added.

13. The process according to claim 11, wherein in step (c), at least one filler is further added.

14. The process according to claim 11, characterized in that the steps (c) and (d) are carried out continuously and degassing is carried out during said steps.

15. A process for surface lamination, comprising applying a reactive hot melt adhesive composition according to any of claims 1 to 10 to a substrate by means of an applicator roll .

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