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

Abstract

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

Description

[0001] Reactive hot melt adhesive compositions based on alpha-silane-terminated organic polymers

[0002] The present invention relates to reactive hot-melt adhesive compositions. The invention further relates to processes for their preparation and a process for surface lamination using the composition.

[0003] Reactive hot melt adhesives occupy a large market share due to their advantages, such as short setting time, high initial strength and durability, are used in a wide variety of applications and have replaced solvent-based adhesives in many applications (see e.g. Bodo Müller, Walter Rath, Formulation of Adhesives and Sealants, Vincentz Network; 1st edition, December 2004).

[0004] The most important representatives among reactive hot melt adhesives are moisture-curing polyurethanes based on methylene diphenyl diisocyanate (MDI). The handling of monomeric MDI has recently been restricted under REACH due to its sensitizing effects, as stated in EU Regulation 2020 / 1149.

[0005] The patent literature describes processes for the production of low-monomer reactive polyurethane hot melt adhesives based on MDI (see, for example, WO 03 / 055929 A1, WO 01 / 40342 A1, WO 03 / 033562 A1, WO 03 / 006521 A1).

[0006] Furthermore, processes for the silanization of polyurethane hot melt adhesives are described, which represent an isocyanate-free alternative. In this process, moisture-curing di- or trialkoxysilane units are generally introduced. One possible production option is the reaction of the isocyanate groups of reactive polyurethane hot melt adhesives with secondary aminosilanes (e.g., WO 2004 / 005420 A1). Aminosilanes, tin accelerators, and / or strong nitrogen bases (e.g., 1,8-diazabicyclo[5.4.0]undec-7-ene) are generally used to accelerate the crosslinking reaction. The disadvantage of this process is that these accelerators can simultaneously promote the hydrolysis of the ester units usually present in reactive polyurethane hot melt adhesives. Furthermore, the formulations obtained in this way are generally no longer sufficiently stable to be processed on roller coating machines.Reactive hot melt adhesives are often applied using roller applicators and are often exposed to ambient humidity. The formulations must therefore be sufficiently stable and, even during short system downtimes, must not react with the ambient humidity to such an extent that a significant increase in the application rate and stringing occur, the latter of which negatively affects the application pattern.

[0007] Stable hot melt adhesive formulations based on silane-terminated polymers represent an interesting class of adhesives. Furthermore, such silane-functional adhesives exhibit a broad adhesion spectrum, which can be an advantage compared to isocyanate-curing systems, for example. Since a silane group in silane-terminated polymers can typically undergo two to three condensation reactions, a higher crosslinking density is also possible compared to structurally comparable isocyanate-based binders. It would be advantageous, among other things, that these can be reliably processed at high temperatures, sometimes using applicator rollers, and that they exhibit the high initial adhesion typical for this application, as well as a chemical curing rate acceptable for industrial applications.

[0008] In the course of this development, two approaches were pursued to produce silane-based formulations. In addition to the silanization of existing reactive PUR hot melt adhesives described in more detail above, in which their isocyanate groups are chemically reacted with secondary aminosilanes, commercially available silane binders are formulated with crystalline or amorphous resins to achieve high initial adhesion.

[0009] For example, WO 2007 / 074143 A1 describes moisture-curing hot-melt adhesive compositions using silane-functionalized polyurethane prepolymers.

[0010] WO 2013 / 026654 A1 describes crosslinkable compositions based on organyloxysilane-terminated polymers. As in DE 10 2013213 835 A1, blends of alpha-silanes, such as Geniosil® STP-E10, and silicone resins are described.

[0011] WO 2011 / 087741 A2 describes adhesives for binding books and related articles and the production of such adhesives using silane-modified liquid polymers. In particular, the adhesives are said to have a reduced content of monomeric diisocyanates or no content of monomeric diisocyanates.

[0012] The result was initially unsatisfactory in both cases. The resulting formulations had insufficient initial adhesion, were not roller-stable, or cured too slowly. Polyester and polyacrylate resins, among others, can be considered to improve initial adhesion. Polyester resins are at risk of degradation through hydrolysis, which is catalyzed by the accelerators typical for silane adhesives, such as aminosilanes. Suitable crystalline polyacrylate resins, on the other hand, must be melted at very high temperatures (approx. 150 °C). However, commercially available polyether-based silane binders are not stable at these temperatures.

[0013] An object of the present invention was therefore to provide reactive hot melt adhesive compositions which do not have the above-mentioned disadvantages or at least have them to a lesser extent.

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

[0015] The object was also achieved by a process for producing a reactive hot melt adhesive composition according to the present invention comprising the steps

[0016] (a) adding at least one acrylate resin-based polymer to at least one chemical compound which is liquid at least at 100 °C and in which the at least one acrylate resin-based polymer dissolves at least at 150 °C, or adding to a mixture containing the at least one chemical compound at a temperature in the range of 130 °C to 170 °C;

[0017] (b) cooling the mixture to a temperature in the range of 80°C to 120°C;

[0018] (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, thereby obtaining a reactive hot-melt adhesive composition according to the present invention.

[0019] The object was also achieved by a method for surface lamination comprising the step of applying a reactive hot-melt adhesive composition according to the present invention to a substrate by means of an application roller.

[0020] The requirement for a roller-stable adhesive at processing temperatures of 100-120 °C with a reasonable curing rate was surprisingly met with binders based on silane-terminated polymers (so-called alpha-silanes). An acrylate resin-based polymer was used that can be dissolved at least at 150 °C with the aid of a chemical compound that is liquid at least at 100 °C, as well as with the aid of at least one oligomeric silane containing one or more amino groups. In this way, hydrolysis-stable formulations with satisfactory initial adhesion could be produced. Furthermore, the reactive hot-melt adhesive compositions according to the invention exhibit high crosslinking densities, which can provide good plasticizer resistance.

[0021] Accordingly, the reactive hot-melt adhesive composition according to the present invention represents a moisture-curing adhesive formulation based on alpha-silane-terminated polymers with low viscosity at 100 °C and largely roller-stable. These polymers exhibit sufficiently high initial adhesion at room temperature for surface lamination and cure chemically sufficiently quickly. During curing, alcohol (especially methanol, possibly also ethanol) is released through a condensation reaction, forming siloxane groups.

[0022] More precisely, with alpha-silanes, a two-stage condensation reaction of alkoxysilanes is known to occur largely autocatalytically (alpha effect) through the donor atom (e.g., nitrogen atom) located alpha to the silicon atom. The reactive hot-melt adhesive compositions according to the present invention are accelerated by aminosilanes and do not require the use of additional co-catalysts such as organotin compounds or diazabicycloundecene. Surprisingly, it has been shown in the course of this invention that formulations containing an alpha-silane are roller-stable over a period of approximately 30-60 minutes at 100 °C without enclosure under normal room conditions (room temperature approximately 20-23 °C, room humidity approximately 30-65% RH) and, despite the moderate acceleration and without the use of additional co-catalysts, cure chemically sufficiently quickly.

[0023] The present invention accordingly relates to a reactive hot-melt adhesive composition. The term "hot-melt adhesive 1 describes an adhesive that is solid at room temperature or has a high shear modulus and is in liquid form at elevated temperatures, usually between 100°C and 120°C. Hot melt adhesives are applied in liquid form and solidify again, so that they are once again in solid form at room temperature or have a high shear modulus. In addition, "reactive" hot melt adhesives are characterized by the fact that they crosslink through a chemical reaction. This usually involves a reaction with water, which comes into contact with the hot melt adhesive, for example in the form of atmospheric moisture. These are therefore referred to as moisture-curing. This also applies to the reactive hot melt adhesive compositions of the present invention.

[0024] The reactive hot-melt adhesive composition of the present invention is also liquid at a temperature of 100°C to 120°C. These typically have a viscosity of 4000 mPas to 12000 mPas. The reactive hot-melt adhesive composition of the present invention is preferably isocyanate-free.

[0025] The reactive hot-melt adhesive composition according to the present invention contains components a) to d). Furthermore, the composition according to the invention may comprise further components. Accordingly, one embodiment of the present invention relates to a reactive hot-melt adhesive composition consisting of components a) to d). A further embodiment of the present invention relates to a reactive hot-melt adhesive composition which, in addition to components a) to d), further comprises one or more components, such as two, three, four, five, six, seven, eight, nine, or ten.

[0026] Component a) of the reactive hot-melt adhesive composition according to the invention represents at least one alpha-silane-terminated organic polymer. Accordingly, the reactive hot-melt adhesive composition according to the present 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 simplifies this mixture of substances. Alpha-silane-terminated organic polymers are known to the person 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.

[0027] 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, reactive hot-melt adhesive compositions of the present invention are alpha-silane-terminated hot-melt adhesives that can react with moisture to form siloxanes.

[0028] Preferably, the at least one alpha-silane-terminated organic polymer is a polymer having a plurality of end groups of the formula

[0029] *-XC(=O)-N(R)-C(R 1 R 2 )-Si(R 3 )a(OR 4 )3-a, where

[0030] X is O or N(R); each R independently is hydrogen or a hydrocarbon radical having 1 to 20 carbon atoms;

[0031] R 1 and R 2 independently of one another represent hydrogen or a hydrocarbon radical having 1 to 20 carbon atoms;

[0032] R 3 and R 4 independently of one another represent a hydrocarbon radical having 1 to 20 carbon atoms; a represents 0, 1 or 2 and

[0033] “*” indicates the bond for attachment to the polymer.

[0034] 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.

[0035] Particularly preferably, R is hydrogen. More preferably, R 1 and R 2 The same. R 1 and R 2 Hydrogen or an alkyl radical having 1 to 4 carbon atoms, where the alkyl radical may be straight-chain or branched. More preferably, R 1 and R 2 H, methyl or ethyl, more preferably hydrogen or methyl.

[0036] Particularly preferred are R 1 and R 2 Hydrogen.

[0037] More preferred are R 3 and R 4 The same. R 3 and R 4an alkyl radical having 1 to 4 carbon atoms, where the alkyl radical may be straight-chain or branched. More preferably, R 3 and R 4 methyl or ethyl.

[0038] Particularly preferred are R 3 and R 4 Methyl.

[0039] Preferably a = 1 or 2, more preferably a = 1 .

[0040] An exemplary at least one alpha-silane-terminated organic polymer is a polymer having a plurality of end groups of the formula *-OC(=O)-NH-CH2-Si(CH3)(OCH3)2.

[0041] The plurality of end groups described in more detail above terminates an organic polymer. 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 contains no further silane groups beyond the end groups listed above.

[0042] 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.

[0043] Component a) has a proportion of 3 wt.% to 49 wt.% based on the total weight of the composition. Preferably, the proportion is 3 to 20 wt.%, more preferably 5 to 20 wt.%.

[0044] Furthermore, the reactive hot-melt adhesive composition according to the present invention comprises at least one acrylate resin-based polymer as component b). Accordingly, the composition according to the invention can comprise one or more, such as two, three, or four, acrylate-based 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 simplifies this mixture of substances. Component b) preferably consists only of an acrylic resin-based polymer.

[0045] If component a) is also an acrylate resin-based polymer as an organic polymer, components a) and b) can be distinguished by the fact that component b) does not have any alpha-silane-terminated groups.

[0046] Preferably, the acrylate-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.

[0047] The proportion of component b) is 1 wt.% to 20 wt.%, based on the total weight of the reactive hot-melt adhesive composition according to the invention. Preferably, the proportion is 1 wt.% to 10 wt.%. More preferably, the proportion is 8 wt.% to 9 wt.%.

[0048] Component b) serves to achieve sufficient initial adhesion. A copolymer consisting of methyl methacrylate and n-butyl methacrylate is particularly preferred.

[0049] The at least one acrylate resin-based polymer can be crystalline, partially crystalline, or amorphous and thus has a melting point, melting range (here, the lower temperature point is considered the melting point), or glass transition temperature. This temperature is preferably in a range from 30°C to 300°C, more preferably in a range from 30°C to 250°C, even more preferably in a range from 30°C to 150°C, even more preferably in a range from 30°C to 80°C, even more preferably in a range from 40°C to 75°C, even more preferably in a range from 50°C to 70°C, and in particular at 60°C. The at least one acrylate resin-based polymer is preferably amorphous, so that the specified temperature values ​​then refer to its glass transition temperature.

[0050] Preferably, the at least one acrylate resin-based polymer has an average weight-average molecular weight in the range from 10,000 g / mol to 150,000 g / mol. More preferred is a range from 25,000 g / mol to 125,000 g / mol, further more preferred is a range from 30,000 g / mol to 110,000 g / mol, further more preferred is a range from 35,000 g / mol to 100,000 g / mol, further more preferred is a range from 40,000 g / mol to 90,000 g / mol, further more preferred is a range from 45,000 g / mol to 80,000 g / mol, further more preferred is a range from 50,000 g / mol to 70,000 g / mol and in particular the average weight-average molecular weight is 60,000 g / mol.

[0051] As component c), the reactive hot-melt adhesive composition contains at least one chemical compound which is liquid at least at 100 °C and in which the at least one acrylate resin-based polymer dissolves at least at 150 °C.

[0052] For the purposes of the present invention, "dissolved at least at 150°C" refers to the dissolution of a solid acrylic resin-based polymer. However, dissolution can also occur at lower temperatures. If the melting point, melting range, or glass transition temperature is below 150°C, "dissolved" refers to the creation of a single-phase mixture with the chemical compound.

[0053] Component c) can comprise one chemical compound or several compounds, such as two, three, or four. Advantageously, it comprises only one compound. Component c) is different from components a) or b). A compound is therefore considered component c) if it is capable of dissolving component b) at least at 150 °C, within the scope of its possible proportions in the overall composition, and is itself liquid at least at 100 °C, and if it differs from components a) and b).

[0054] The proportion of component c) is 1 wt.% to 20 wt.%, based on the total weight of the reactive hot-melt adhesive composition according to the invention. Preferably, the proportion is 1 wt.% to 10 wt.%. More preferably, the proportion is 6 wt.%.

[0055] The only thing that is important for the chemical compound, apart from its solubility, is that it is liquid at least at 100°C. Numerous compounds can be used, and those skilled in the art are able to find suitable compounds through simple dissolution tests. Examples of compounds that can be used are listed below. Advantageously, the at least one chemical compound that is liquid at least at 100°C and in which the at least one acrylate resin-based polymer dissolves at least at 150°C can be a plasticizer. Examples of plasticizers are known in the art. Reference is made to the examples listed in DIN EN ISO 1043-3 (2017-03).

[0056] Examples of plasticizers are:

[0057] Alkylsulfonsäureester Diisooctylmaleat N-Butylbenzolsulfonamid Butyl-O-acetylrizinoleat Diisooctylphthalat Nonylundecyladipat Benzylbutylphthalat Diisooctylsebazat Nonylundecylphthalat Butylcyclohexylphthalat Diisooctylazelat Octyldecyladipat Butylnonylphthalat Diisopentylphthalat Octyldecylphthalat Benzyloctyladipat Di-2-Methyloxyethylphthalat n-Octyldecyltrimellitat Butyloctylphthalat Dimethylphthalat Paraffinöl Butylstearat Dimethylsebazat Polypropylenadipat Dibutyladipat Dinonylfumarat Polypropylensebazat Di-2-Butoxyethylphthalat Dinonylmaleat Sucroseoctaacetat Dibutylfumarat Di-n-octylphthalat T ributyl-O-acetylcitrat Dibutylmaleat Dinonylphthalat T ri-2-Butoxyethylphosphat Dibutylphthalat Dinonylsebazat Tributylphosphat Dibutylsebazat Dioctyladipat T richlorethylphosphat Dibutylazelat Dioctylisophthalat Trikresylphosphat Dicyclohexylphthalat Dioctylphthalat T ri-2,3-dibrompropylphosphat Dicaprylphthalat Dioctylsebazat T ri-2,3-dichlorpropylphosphat Didecylphthalat Dioctylterephthalat T riethyl-o-acetylcitrat,

[0058] Diethylenglycoldibenzoat Dioctylazelat T etrahydrofurfuryloleat Diethylphthalat Diphenylkresylphosphat Triheptyltrimellitat Diheptylphthalat Di-Propylenglycoldibenzoat Triisooctyltrimellitat Dihexylphthalat Diphenyloctylphosphat Trioctylphosphat Diisobutyladipat Diphenylphthalat Tetraoctylpyromellitat Diisobutylmaleat Diisotridecylphthalat Trioctyltrimellitat Diisobutylphthalat Diundecylphthalat Triphenylphosphat Diisodecyladipat Epoxidiertes Leinsamenöl Trixylylenphosphat

[0059] 1 ,2-Cyclohexandicarbonsäure-

[0060] Diisodecylphthalat Epoxidiertes Sojabohnenöl diisononylester Diisoheptylphthalat Glycerintriacetat Isodecylbenzoat

[0061] Diisohexylphthalat Heptylnonylundecyladipat

[0062] Diisononyladipat Heptylnonylundecylphthalat

[0063] Diisononylphthalat Hexyloctyldecyladipat

[0064] Diisooctyl adipate hexyloctyl decyl phthalate

[0065] Such plasticizers are commercially available. An example is Hexamoll® DINCH from BASF SE, Ludwigshafen (Germany). Preferred plasticizers are 1,2-cyclohexanedicarboxylic acid diisononyl ester or isodecyl benzoate.

[0066] It is also possible for the at least one chemical compound that is liquid at least at 100°C and in which the at least one acrylate resin-based polymer dissolves at least at 150°C to 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 from 500 g / mol to 5000 g / mol, more preferably in the range from 750 g / mol to 4000 g / mol, more preferably in the range from 1000 g / mol to 3000 g / mol; in particular, the number-average molecular weight is 2000 g / mol.

[0067] It is also possible that the at least one chemical compound that is liquid at least at 100°C and in which the at least one acrylate resin-based polymer dissolves at least at 150°C is an alkoxysilane. Alkoxysilanes are commercially available. An example is the one from Evonik Industries AG, Essen (Germany), under the trade name Tegopac®. This is a binder with side-crosslinking ethoxysilanes.

[0068] The reactive hot-melt adhesive composition according to the invention further contains a component d) which contains at least one oligomeric silane containing one or more amino groups. Thus, component d) can comprise one or more, such as two, three, or four, such silanes. Preferably, component d) consists of only one component. Component d) is different from components a) to c) and only counts as component d) insofar as it cannot be considered one of components a) to c).

[0069] The at least one oligomeric silane of component d) containing one or more amino groups preferably represents a mixture of amino group-containing alkoxy / hydroxysilanes and / or silanols and condensation and cocondensation products based thereon and preferably has a molecular weight of more than 500 g / mol.

[0070] Such oligomeric silanes containing one or more amino groups are commercially available, for example as Dynasylan® 1146 from Evonik. These are described, for example, in DE 10 2007 040 802 A1. Accordingly, their preparation can be described as follows.

[0071] As already explained above, the at least one oligomeric silane containing one or more amino groups is a mixture which can be obtained by

[0072] (A) at least one aminoalkylalkoxysilane of the general formula I

[0073] NR'2[(CH2)2NR'] X -Y-Si(R") n (OR)3-n (I), wherein groups R, R' and R" are the same or different and each represent a hydrogen atom or a linear or branched alkyl group having 1 to 8 C atoms, Y represents a bivalent 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

[0074] (B) at least one bis-silylated alkylamine of the general formula II (RO)3-m(R")mSi-Y-[NR'(CH2)2] y NR'[(CH2)2NR']zY-Si(R")n(OR)3- n (II), wherein groups R, R' and R" are the same or different and each represent a hydrogen atom or a linear or branched alkyl group having 1 to 8 C atoms, groups Y are the same or different and Y represents a bivalent 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

[0075] (C) at least one tris-silylated alkylamine of the general formula III

[0076] N[-Y-Si(R")n(OR)3-n]3 (III), wherein groups R and R" are the same or different and each represent a hydrogen atom or a linear or branched alkyl group having 1 to 8 C atoms, Y independently represents a bivalent alkylene group from the series -CH2-, -(CH2)2-, -(CH2)3- or -[CH2CH(CH3)CH2]- and n independently represents 0 or 1, or (D) at least two of the aforementioned silylated alkylamines of the general formula I, II and III are hydrolyzed with a defined amount of water and optionally with the addition of an acid and condensed or co-condensed and the free alcohol is substantially removed from the system.

[0077] In this context, mono-silylated amines are understood to mean those according to formula I. Oligo-silylated amines are understood to mean, in particular, those which carry two or more than two silyl groups on an amino group or alkylamine, for example according to formula II (bis-silylated) or formula III (tris-silylated) and / or corresponding compounds, which may also be cyclized.

[0078] In the preparation of the mixture, the aminoalkylalkoxysilanes of the general formula I are preferably

[0079] H2N(CH2)3Si(OCH3)3 (AMMO),

[0080] H2N(CH2)3Si(OC2H5)3 (AMEO),

[0081] H2N(CH2)2NH(CH2)3Si(OCH3)3 (DAMO),

[0082] H2N(CH2)2NH(CH2)2NH(CH2)3Si(OCH3)3 (TRIAMO), and possibly corresponding cyclic compounds.

[0083] As compounds according to formula II, preference is given to

[0084] (H3CO)3Si(CH2)3NH(CH2)3Si(OCH3)3 (Bis-AMMO),

[0085] <h2 style=";text-align:left;direction:ltr">(H5C2O)3Si(CH2)3NH(CH2)3Si(OC2H5)3 (Bis-AMEO),<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0086] <h2 style=";text-align:left;direction:ltr"> (H3CO)3Si(CH2)3NH(CH2)2NH(CH2)2NH(CH2)3Si(OCH3)3 (Bis-DAMO),<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0087] <h2 style=";text-align:left;direction:ltr"> (H3CO)3Si(CH2)3NH(CH2)2NH(CH2)2NH(CH2)2NH(CH2)2NH(CH2)3Si(OCH3)3 (Bis-TRIAMO), sowie als verbindungen gemäß Formel III<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0088] <h2 style=";text-align:left;direction:ltr"> N[CH2)3Si(OCH3)3]3 (Tris-AMMO),<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0089] <h2 style=";text-align:left;direction:ltr"> N[CH2)3Si(OC2H5)3]3 (Tris-AMEO).<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0090] For the preparation of the mixture, at least one component (A) is preferably selected 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) can be made from the series Bis-AMMO, Bis-AMEO, Bis-DAMO, and component (C) from the series Tris-AMMO, Tris-AMEO. Likewise, mixtures containing compounds of the general formulas I, II, and / or III can advantageously be used to prepare the mixture. Such usable mixtures can also contain so-called condensation products of said aminoalkoxysilanes. Condensation products or reaction products of aminoalkoxysilanes of the general formulas I, II and / or III are suitably understood to mean those dimeric, trimeric, tetrameric or higher oligomeric products which are generally obtained by condensation or.Cocondensation and / or prehydrolysis of the respective monomers with elimination of alcohol. In corresponding condensates or cocondensates, the reactant components are thus linked via Si-O-Si bonds. It is also known that a cycle opens upon hydrolysis or alcoholysis, yielding the corresponding aminoalkylalkoxysilane or aminoalkylsilanol. Compounds of general formula II can also exist in cyclic or bicyclic form and be used as such.

[0091] According to chemical understanding, the reaction essentially produces a mixture of amino group-containing alkoxy / hydroxy silanes and / or silanols as well as condensation and co-condensation products based thereon (corresponding linear, branched, cyclic and possibly spatially cross-linked siloxanes) starting from compounds of the general formulas I, II or III and / or corresponding condensation products.

[0092] In the preparation of the mixture, the reaction, in particular hydrolysis and condensation or cocondensation, is preferably carried out at a temperature of < 100°C, preferably from 10 to 80°C, particularly preferably from 15 to 60°C, in particular from 20 to 50°C.

[0093] Optionally, an organic or inorganic acid can be used in the preparation of the mixture. Hydrochloric acid (HCl or aqueous hydrochloric acid), aqueous acetic acid, or aqueous formic acid can be advantageously used, with the proportion of water introduced thereby simultaneously being added to the amount of water to be introduced according to the invention for the targeted hydrolysis of the alkoxysilanes. However, acid can also be added after the preparation of the mixture, preferably adjusting to a pH of 2 to 6, in particular 3 to 5.

[0094] In particular, the preparation of the mixture involves distillation of the product mixture from the reaction, i.e., the components that would otherwise be highly volatile under ambient conditions, in particular the hydrolysis alcohol and any added solvent or diluent, are distilled off at least partially from the resulting product mixture, preferably with gentle heating and under reduced pressure. If necessary, the amount of volatile components removed from the system can be replaced by an equal volume of water and / or acid.

[0095] Thus, the mixture can preferably contain an organic or inorganic acid, with a degree of neutralization of the aminoalkyl and oligosilylated aminoalkyl groups suitably ranging from 0 to 125%, preferably 0.1 to 120%, particularly preferably 70 to 115%, and most preferably 75 to 110%, based on the amine number. The amine number can generally be determined according to DIN 32 625 (potentiographic titration with HCl).

[0096] The acid used is preferably an inorganic or organic acid, in particular hydrochloric acid, acetic acid or formic acid, wherein the aminoalkyl and oligo-silylated aminoalkyl-functional silicon compounds in the present composition are chemically understood to be present at least partially as a cationic amine mixture, ie a composition used according to the invention preferably contains an acid and / or a corresponding salt of acid and one of the amino-functional compounds present.

[0097] The mixture may have a viscosity of 2 to 1000 mPa s, preferably 3 to 500 mPa s, particularly preferably 4 to 250 mPa s, wherein the viscosity can be determined, for example, according to DIN 53 015.

[0098] The proportion of component d) is 0.001 wt.% to 5 wt.%, based on the total weight of the hot-melt adhesive composition according to the invention. Preferably, the proportion is 0.001 wt.% to 2 wt.%. Further preferably, the proportion is 1.2 wt.%.

[0099] In addition to the components a) to d) listed above, the hot melt adhesive composition according to the invention may contain further components.

[0100] Thus, the hot-melt adhesive composition according to the invention can contain at least one silicone resin, such as a phenylsilicone resin. 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, provided it is not already one of the components described above. Accordingly, possible silicone resins according to DE 10 2013 213 835 A1 contain units of the formula

[0101] R 3 c'(R 4 'O)d'R 5 eSiO(4-c'-d'- e ') / 2 (II), where

[0102] R 3 ' may 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 formula (II),

[0103] R 4 ' may be the same or different and represents a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical,

[0104] R 5' can be the same or different and denotes 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 the formula (II) the sum c' + e' is equal to 0 or 1.

[0105] Suitable silicone resins preferably consist of at least 90% by weight of units of formula (II), particularly preferably exclusively of units of formula (II).

[0106] Examples of residues 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-, and p-tolyl radicals; xylyl radicals, and ethylphenyl radicals; and aralkyl radicals, such as the benzyl radical, the o-, and ß-phenylethyl radicals. 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.

[0107] Preferably, the residue R 3 ' are monovalent hydrocarbon radicals having 1 to 6 carbon atoms, optionally substituted by halogen atoms, particularly preferably alkyl radicals having 1 or 2 carbon atoms, in particular the methyl radical. The radical R can be 3 ' but may also be divalent aliphatic radicals which link two silyl groups of the formula (II) to one another, such as alkylene radicals having 1 to 10 carbon atoms, such as methylene, ethylene, propylene or butylene radicals.

[0108] Preferably, the residue R 3' however, are monovalent SiC-bonded aliphatic hydrocarbon radicals having 1 to 18 carbon atoms, optionally substituted by halogen atoms, particularly preferably aliphatic hydrocarbon radicals having 1 to 6 carbon atoms, in particular the methyl radical.

[0109] Examples of remainder R 4 ' are hydrogen atoms or the radical R 3 ' given examples.

[0110] Preferably, the residue R 4 ' a hydrogen atom or optionally substituted by halogen atoms alkyl radicals having 1 to 10 carbon atoms, particularly preferably alkyl radicals having 1 to 4 carbon atoms, in particular the methyl and ethyl radicals.

[0111] Examples of residues R 5 ' are the ones above for R 3 ' aromatic residues indicated.

[0112] Preferably, the residue R 5' are 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.

[0113] Preferably, silicone resins are used in which at least 90% of all residues R 3 ' for methyl residue, at least 90% of all residues R 4 ' represents methyl, ethyl, propyl or isopropyl radical and at least 90% of all radicals R 5 ' stands for phenyl residue.

[0114] Preference is given to using silicone resins which contain at least 40%, particularly preferably at least 60%, of units of formula (II) in which c' is 0, based in each case on the total number of units of formula (II). Preference is given to using silicone resins which contain at least 70%, particularly preferably at least 80%, of units of formula (II) in which d' is 0 or 1, based in each case on the total number of units of formula (II).

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] Examples of silicone resins are organopolysiloxane resins consisting essentially, preferably exclusively, of (Q) units of the formulas SiO4 / 2, Si(OR 4 ')O3 / 2, Si(OR 4 ')2O2 / 2 and Si(OR 4 ')3Oi / 2, (T)-units of the formulas PhSiO3 / 2, PhSi(OR 4 ')O2 / 2, PhSi(OR 4 ')2Oi / 2, MeSiO3 / 2, MeSi(OR 4 ')O2 / 2 and MeSi(OR 4 ')2Oi / 2 (D) units of the formulas Me2SiO2 / 2, Me2Si(OR 4 ')Oi / 2, Ph2SiO2 / 2 and Ph2Si(OR 4 ')Oi / 2, MePhSiO2 / 2 and MePhSi(OR 4 ')Oi / 2 and (M) units of the formula MesSiOi^, where Me is a methyl radical, Ph is a phenyl radical and R 4 ' represents hydrogen atom or optionally halogen-substituted alkyl radicals having 1 to 10 carbon atoms, particularly preferably hydrogen atom or alkyl radicals having 1 to 4 carbon atoms, wherein the resin contains 0-2 mol (Q) units, 0-2 mol (D) units and 0-2 mol (M) units per mol (T) units.

[0120] Preferred examples of silicone resins are organopolysiloxane resins consisting essentially, preferably exclusively, of T units of the formulas PhSiC>3 / 2, PhSi(OR 4 ')C>2 / 2 and PhSi(OR 4 ')2Oi / 2, T-units of the formulas MeSiOa / 2, MeSi(OR 4 ')C>2 / 2 and MeSi(OR 4 ')2Oi / 2 as well as D-units of the formulas Me2SiC>2 / 2 and Me2Si(OR 4 ')Oi / 2, where Me is a methyl radical, Ph is a phenyl radical and R 4 ' represents a hydrogen atom or an alkyl radical having 1 to 10 carbon atoms which is optionally substituted by halogen atoms, particularly preferably a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms, with a molar ratio of (T) to (D) units of 0.5 to 2.0.

[0121] Among these examples, silicone resins are particularly preferred whose units of formula (II) consist of at least 50%, preferably at least 70%, in particular at least 85% of T- units of the formulas PhSiC>3 / 2, PhSi(OR 4 ')C>2 / 2, PhSi(OR 4 ')2Oi / 2, MeSiOs / 2, MeSi(OR 4 ')C>2 / 2 and MeSi(OR 4 ')2Oi / 2 are formed, wherein these silicone resins contain at least 30%, preferably at least 40%, in particular at least 50% T-units of the formulas PhSiC>3 / 2, PhSi(OR 4 ')C>2 / 2 and PhSi(OR 4 ')2Oi / 2 and at least 10%, preferably at least 15%, in particular at least 20% T-units of MeSiOs / 2, MeSi(OR 4 ')C>2 / 2 and MeSi(OR 4 ')2Oi / 2 contained.

[0122] 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.

[0123] Such silicone resins can be either solid or liquid at 23°C and 1000 hPa, with silicone resins preferably being liquid.

[0124] 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.

[0125] Furthermore, the reactive hot melt adhesive composition according to the present

[0126] The invention additionally contains at least one tackifying polymer (tackifier). The proportion is advantageously between 10% by weight and 40% by weight, based on the total weight of the composition.

[0127] Furthermore, the reactive hot-melt adhesive composition according to the present invention can additionally contain at least one filler. Advantageously, the filler content is 10% to 40% by weight based on the total weight of the composition. Examples of fillers are calcium carbonate, for example, chalk, or corundum, such as fused alumina. The use of filler can prevent or reduce stringing during processing of the adhesive composition.

[0128] The reactive hot-melt adhesive compositions according to the invention allow for high filler levels, which can be advantageous in various applications. Examples include applications that require good thermal conductivity or special requirements regarding fire behavior.

[0129] Another aspect of the present invention is a process for preparing a reactive hot melt adhesive composition according to the present invention, which comprises steps (a) to (d).

[0130] In a first step (a), at least one acrylate resin-based polymer is added to at least one chemical compound which is liquid at least at 100 °C and in which the at least one acrylate resin-based polymer dissolves at least at 150 °C.

[0131] Likewise, the at least one acrylic resin-based polymer can be added to a mixture containing the at least one chemical compound.

[0132] The addition takes place at a temperature in the range of 130 °C to 170 °C, preferably in the range of 140 °C to 160 °C, in particular at 150 °C.

[0133] Furthermore, a tackifying polymer can be added in step (a).

[0134] In a next step (b), the mixture is cooled to a temperature in the range of 80°C to 120°C.

[0135] This is followed, in step (c), by adding at least one alpha-silane-terminated organic polymer to the cooled mixture. Finally, in step (d), at least one oligomeric silane containing one or more amino groups is added, thereby obtaining a reactive hot-melt adhesive composition according to the present invention.

[0136] In step (c), at least one filler may additionally be added. Preferably, steps (c) and (d) are carried out sequentially in such a way that degassing can occur between the steps.

[0137] The reactive hot-melt adhesive composition according to the invention is roller-stable and therefore suitable for application via rollers. Accordingly, the reactive hot-melt adhesive composition according to the invention is particularly suitable for a process for surface lamination in which the reactive hot-melt adhesive composition according to the present invention is applied to a substrate using an applicator roller.

[0138] Surprisingly, it has been shown that the application can be cleaned using a roller coating machine even after the roller stability period has been exceeded, ie when the binder exhibits noticeable stringing during processing, which determines the application pattern.

[0139] Accordingly, a further object of the present invention is the use of a reactive hot melt adhesive composition according to the invention for roller application.

[0140] Advantageous applications of the reactive hot-melt adhesive compositions according to the invention arise from their good adhesion and initial tack. Even in cases where no roller application is used, for example, in window profile wrapping, the advantageous properties listed below are evident. Further applications include those in which improved thermal conductivity can be achieved. Applications associated with improved fire behavior should also be mentioned.

[0141] The following advantages are particularly evident:

[0142] Isocyanate-free, good adhesion spectrum, especially on metals, glass and other materials. No foaming due to CO2 formation.

Claims

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

2. Reactive hot melt adhesive composition according to claim 1, characterized in that the at least one alpha-silane-terminated organic polymer comprises 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 exhibits, whereby X stands for O or N(R); each R independently stands for hydrogen or a hydrocarbon residue with 1 to 20 carbon atoms; R 1 and R 2 independently of each other they stand for hydrogen or a hydrocarbon residue with 1 to 20 carbon atoms; R 3 and R 4 independently of each other, they represent a hydrocarbon residue with 1 to 20 carbon atoms; a represents 1 or 2 and “*” indicates the bond for attachment to the polymer.

3. Reactive hot melt adhesive composition according to claim 1 or 2, characterized in that the organic polymer is a polyoxyalkylene, a hydrocarbon polymer, a polyurethane, a polyester, a polyamide, a polyacrylate, a polymethacrylate or a polycarbonate.

4. Reactive hot melt adhesive composition according to one of claims 1 to 3, characterized in that the acrylate resin-based polymer is a homoacrylate, a 22 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. Reactive hot melt adhesive composition according to one of claims 1 to 4, characterized in that the at least one chemical compound, which is liquid at least at 100 °C and in which the at least one acrylate resin-based polymer dissolves at least at 150 °C, is a plasticizer.

6. Reactive hot melt adhesive composition according to one of claims 1 to 4, characterized in that the at least one chemical compound, which is liquid at least at 100 °C and in which the at least one acrylate resin-based polymer dissolves at least at 150 °C, is a polyalkylene glycol.

7. Reactive hot melt adhesive composition according to one of claims 1 to 4, characterized in that the at least one chemical compound, which is liquid at least at 100 °C and in which the at least one acrylate resin-based polymer dissolves at least at 150 °C, is an alkoxysilane.

8. Reactive hot melt adhesive composition according to one of claims 1 to 7, characterized in that the at least one oligomeric silane containing one or more amino groups is a mixture of amino group-containing alkoxy / hydroxo-silanes and / or silanols as well as condensation and co-condensation products based thereon and preferably has a molecular weight of more than 500 g / mol.

9. Reactive hot melt adhesive composition according to one of claims 1 to 8, characterized in that the composition additionally comprises 10 wt.% to 40 wt.% of at least one tackifier polymer based on the total weight of the composition.

10. Reactive hot melt adhesive composition according to one of claims 1 to 9, characterized in that the composition additionally comprises 10 wt.% to 40 wt.% of at least one filler based on the total weight of the composition.

11. A method for producing a reactive hot melt adhesive composition according to any one of claims 1 to 10, comprising the steps (a) Adding at least one acrylate resin-based polymer to at least one chemical compound which is liquid at least at 100 °C and in which the at least one acrylate resin-based polymer dissolves at least at 150 °C, or adding to a mixture containing the at least one chemical compound 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, wherein a reactive hot melt adhesive composition is obtained according to any one of claims 1 to 10.

12. Method according to claim 11, characterized in that a sticky polymer is further added in step (a).

13. Method according to claim 11 or 12, characterized in that at least one filler is additionally added in step (c).

14. Method according to one of claims 11 to 13, characterized in that steps (c) and (d) are carried out successively and degassing takes place between the steps.

15. Method for surface lamination including the step Applying a reactive hot melt adhesive composition according to one of claims 1 to 10 to a substrate using an application roller.