DE102024114875A1 - Reactive hot melt adhesive compositions based on alpha-silane-terminated organic polymers - Google Patents

Abstract

The present invention relates to a reactive hot melt adhesive composition, based on the total weight of the composition, comprising: a) 3 wt.% to 79.999 wt.% of at least one alpha-silane-terminated organic polymer; b) 20 wt.% to 96.999 wt.% of at least one silane-terminated polyurethane, which is not an alpha-silane-terminated polyurethane; c) 0 wt.% to 70 wt.% of at least one filler; d) 0.001 wt.% to 3 wt.% of at least one silane, which has a primary or secondary amino group or a blocked amino group that hydrolyzes to the primary or secondary amino group; wherein the at least one silane-terminated polyurethane b), which is not an alpha-silane-terminated polyurethane, is obtained by a reaction in which at least one polyol (1) reacts with at least one polyisocyanate (2), optionally in the presence of at least one chain terminator (3), to form a polyurethane prepolymer which is further reacted with at least one secondary aminosilane (4), which is not an alpha-aminosilane, such that the free isocyanate content is less than 0.1 wt% based on the total weight of the silane-terminated polyurethane b), and wherein, based on the sum of the reactants (1), (2), (3) and (4), the following proportions are obtained: 1) 40 wt% to 85 wt% of the at least one polyol; 2) 10 wt% to 50 wt% of the at least one polyisocyanate; 3) 0 wt% to 25 wt% of the at least one chain terminator; 4) 1 wt.% to 15 wt.% of the at least one secondary aminosilane that is not an alpha-aminosilane. The invention further relates to processes for its production and a process for surface lamination using the composition.

Description

The present invention relates to reactive hot melt adhesive compositions and further to methods for their production as well as a method for surface lamination using the composition.

Reactive hot melt adhesives occupy a large market share due to their advantages, such as a short setting time, high initial strength and resistance, are used in a 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).

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

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 ).

Furthermore, processes for the silanization of polyurethane hot melt adhesives are described, representing an isocyanate-free alternative. In this process, moisture-curing di- or trialkoxysilane units are generally introduced. One method of production involves the reaction of the isocyanate groups of reactive polyurethane hot melt adhesives with secondary aminosilanes (e.g., WO 2004/005420 A1 To accelerate the crosslinking reaction, aminosilanes, tin accelerators, and/or strong nitrogen bases (e.g., 1,8-diazabicyclo[5.4.0]undec-7-ene) are typically used. A disadvantage of this method 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 for processing on roller coating machines. Reactive hot melt adhesives are frequently processed using roller coating machines and are often exposed to ambient humidity. Therefore, the formulations must be sufficiently stable and must not react with the ambient humidity to such an extent, even during short-term machine downtime, that a significant increase in the applied quantity and stringing occur, the latter negatively impacting the coating appearance.

Stable hot melt adhesive formulations based on silane-terminated polymers represent an interesting class of adhesives. Furthermore, such silane-functionalized 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 similar isocyanate-based binders. It would be advantageous if these adhesives could be reliably processed at high temperatures, sometimes using rollers, and exhibited the high initial tack typical for this application, as well as chemical curing acceptable for industrial applications.

In the course of this development, two approaches were initially pursued for the production of silane-based formulations. Besides the silanization of existing reactive PUR hot melt adhesives described above, in which their isocyanate groups are chemically reacted with secondary aminosilanes, the second approach involves the formulation of commercially available silane binders with crystalline or amorphous resins to achieve high initial adhesion.

For example, it describes WO 2007/074143 A1 Moisture-curing hot melt adhesive compositions using silane-functionalized polyurethane prepolymers.

WO 2013/026654 A1 describes crosslinkable materials based on organyloxysilane-terminated polymers. Here, as in DE 10 2013 213 835 A1 Mixtures of alpha-silanes, such as Geniosil® STP-E10 and silicone resins have been described.

WO 2011/087741 A2 This describes adhesives for binding books and related objects, and the production of such adhesives using silane-modified liquid polymers. In particular, it addresses the following: Adhesives may have a reduced content of monomeric diisocyanates or no content of monomeric diisocyanates.

In both cases, the initial result was unsatisfactory. The formulations obtained had insufficient initial adhesion, were not roller-stable, or cured too slowly.

WO 2021/214290 A1 and WO 2023/066902 A1 This document describes adhesive formulations with binders based on silane-terminated polymers with dimethoxy(methyl)silylmethylcarbamate end groups (so-called alpha-silanes). To achieve good initial adhesion, the dissolution of an acrylate resin in a liquid chemical compound is an essential component of these formulations according to the invention. The initial adhesion can optionally be further improved by adding non-reactive resins. However, dissolving an acrylate resin in a liquid chemical compound represents an additional process step, which is associated with higher production costs. The addition of a chemical compound that is liquid at room temperature can, in principle, impair the hot melt adhesive properties of these formulations.

Therefore, there is a need for further improved reactive hot melt adhesive compositions that can at least mitigate or prevent the aforementioned disadvantages.

One object of the present invention is therefore to provide such compositions and methods for their production.

1. a) 3 Gew.-% bis 79,999 Gew.-% mindestens eines alpha-Silan-terminierten organischen Polymers;
2. b) 20 Gew.-% bis 96,999 Gew.-% mindestens eines silanterminierten Polyurethans, das kein alpha-Silan-terminiertes Polyurethan ist;
3. c) 0 Gew.-% bis 70 Gew.-% mindestens eines Füllstoffes;
4. d) 0,001 Gew.-% bis 3 Gew.-% mindestens eines Silans, das eine primäre oder sekundäre Aminogruppe oder eine geblockte Aminogruppe, die zu der primären oder sekundären Aminogruppe hydrolysiert, aufweist;

wobei das mindestens eine silanterminierte Polyurethan b), das kein alpha-Silan-terminiertes Polyurethan ist, erhältlich ist durch eine Reaktion, bei der mindestens ein Polyol (1) mit mindestens einem Polyisocyanat (2) gegebenenfalls in Gegenwart mindestens eines Kettenabbrechers (3) reagiert, so dass ein Polyurethanprepolymer entsteht, das in einer weiteren Reaktion mit mindestens einem sekundären Aminosilan (4), das kein alpha-Aminosilan ist, derart umgesetzt wird, dass der Gehalt an freiem Isocyanat kleiner als 0,1 Gew.-% bezogen auf das Gesamtgewicht des silanterminierten Polyrethans b) ist und wobei bezogen auf die Summe der Reaktanten (1), (2), (3) und (4) sich folgende Anteile ergeben:

• 1) 40 Gew.-% bis 85 Gew.-% des mindestens einer Polyols;
• 2) 10 Gew.-% bis 50 Gew.-% des mindestens einen Polyisocyanats;
• 3) 0 Gew.-% bis 25 Gew.-% des mindestens einen Kettenabbrechers;
• 4) 1 Gew.-% bis 15 Gew.-% des mindestens einen sekundären Aminosilans, das kein alpha-Aminosilan ist.

The problem was solved by a reactive hot melt adhesive composition, based on the total weight of the composition containing

1. a) 3 wt.% to 79.999 wt.% of at least one alpha-silane-terminated organic polymer;
2. b) 20 wt.% to 96.999 wt.% of at least one silane-terminated polyurethane that is not an alpha-silane-terminated polyurethane;
3. c) 0 wt.% to 70 wt.% of at least one filler;
4. d) 0.001 wt.% to 3 wt.% of at least one silane having a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group;

wherein the at least one silane-terminated polyurethane b), which is not an alpha-silane-terminated polyurethane, is obtainable by a reaction in which at least one polyol (1) reacts with at least one polyisocyanate (2), optionally in the presence of at least one chain terminator (3), to form a polyurethane prepolymer which is further reacted with at least one secondary aminosilane (4), which is not an alpha-aminosilane, such that the content of free isocyanate is less than 0.1 wt% based on the total weight of the silane-terminated polyurethane b), and wherein the following proportions result based on the sum of the reactants (1), (2), (3) and (4):

• 1) 40% to 85% by weight of at least one polyol;
• 2) 10 wt.% to 50 wt.% of the at least one polyisocyanate;
• 3) 0 wt.% to 25 wt.% of the at least one chain breaker;
• 4) 1 wt.% to 15 wt.% of at least one secondary aminosilane that is not an alpha-aminosilane.

1. (a) Herstellen mindestens eines silanterminierten Polyurethans b), das kein alpha-Silanterminiertes Polyurethan ist, durch eine Reaktion, bei der mindestens ein Polyol (1) mit mindestens einem Polyisocyanat (2) gegebenenfalls in Gegenwart mindestens eines Kettenabbrechers (3) reagiert, so dass ein Polyurethanprepolymer entsteht, das in einer weiteren Reaktion mit mindestens einem sekundären Aminosilan (4), das kein alpha-Aminosilan ist, derart umgesetzt wird, dass der Gehalt an freiem Isocyanat kleiner als 0,1 Gew.-% bezogen auf das Gesamtgewicht des silanterminierten Polyrethans b) ist und wobei bezogen auf die Summe der Reaktanten (1), (2), (3) und (4) sich folgende Anteile ergeben:
   • 1) 40 Gew.-% bis 85 Gew.-% des mindestens einer Polyols;
   • 2) 10 Gew.-% bis 50 Gew.-% des mindestens einen Polyisocyanats;
   • 3) 0 Gew.-% bis 25 Gew.-% des mindestens einen Kettenabbrechers;
   • 4) 1 Gew.-% bis 15 Gew.-% des mindestens einen sekundären Aminosilans, das kein alpha-Aminosilan ist;
2. (b) Mischen des mindestens einen silanterminierten Polyurethans b) aus Schritt (a) mit dem mindestens einen alpha-Silan-terminierten organischen Polymer (a);
3. (c) Gegebenenfalls Zugeben des mindestens einen Füllstoffes c); und
4. (d) Zugeben des mindestens einen Silans d), das eine primäre oder sekundäre Aminogruppe oder eine geblockte Aminogruppe, die zu der primären oder sekundären Aminogruppe hydrolysiert, aufweist.

The problem was further solved by a method for producing a reactive hot melt adhesive composition according to the invention, comprising steps

1. (a) Producing at least one silane-terminated polyurethane (b), which is not an alpha-silane-terminated polyurethane, by a reaction in which at least one polyol (1) reacts with at least one polyisocyanate (2), optionally in the presence of at least one chain terminator (3), to form a polyurethane prepolymer, which is further reacted with at least one secondary aminosilane (4), which is not an alpha-aminosilane, such that the content of free isocyanate is less than 0.1 wt% based on the total weight of the silane-terminated polyurethane (b), wherein the following proportions are obtained in relation to the sum of the reactants (1), (2), (3) and (4):
   • 1) 40% to 85% by weight of at least one polyol;
   • 2) 10 wt.% to 50 wt.% of the at least one polyisocyanate;
   • 3) 0 wt.% to 25 wt.% of the at least one chain breaker;
   • 4) 1% by weight to 15% by weight of at least one secondary aminosilane that is not an alpha-aminosilane;
2. (b) Mixing the at least one silane-terminated polyurethane (b) from step (a) with the at least one alpha-silane-terminated organic polymer (a);
3. (c) If necessary, adding at least one filler c); and
4. (d) Addition of at least one silane d), which has a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group.

The problem was also solved by a surface lamination method comprising the step of applying a reactive hot melt adhesive composition according to the invention to a substrate using an application roller.

Surprisingly, it has been shown that adhesives with improved properties can be formulated using astonishingly simple silane-terminated polyurethanes containing the components described above. For example, the reactive hot melt adhesive compositions according to the invention are characterized by excellent roller stability, high initial tack, and good curing time. Furthermore, the reactive hot melt adhesive compositions according to the invention can be low-viscosity at temperatures of 90–120 °C. Reliable application via rollers is possible.

It has also been shown that the use of additional resins to improve initial adhesion is not necessary. In particular, the use of non-polar, non-reactive resins can be avoided, as these have the inherent disadvantage that the formulations produced with them exhibit poor adhesion to polar substrates. Due to the increasing hydrophobization, the formulation cures less effectively in the presence of moisture, and the non-reactive components generally weaken or even eliminate the reactive adhesive's properties. The reactive hot melt adhesive compositions according to the invention are therefore particularly suitable for polar substrate surfaces.

Furthermore, the reactive hot melt adhesive compositions according to the invention exhibit high crosslinking densities, which can justify good plasticizer resistance.

1. a) 3 Gew.-% bis 79,999 Gew.-% mindestens eines alpha-Silan-terminierten organischen Polymers;
2. b) 20 Gew.-% bis 96,999 Gew.-% mindestens eines silanterminierten Polyurethans, das kein alpha-Silan-terminiertes Polyurethan ist;
3. c) 0 Gew.-% bis 70 Gew.-% mindestens eines Füllstoffes;
4. d) 0,001 Gew.-% bis 3 Gew.-% mindestens eines Silans, das eine primäre oder sekundäre Aminogruppe oder eine geblockte Aminogruppe, die zu der primären oder sekundären Aminogruppe hydrolysiert, aufweist;

wobei das mindestens eine silanterminierte Polyurethan b), das kein alpha-Silan-terminiertes Polyurethan ist, erhältlich ist durch eine Reaktion, bei der mindestens ein Polyol (1) mit mindestens einem Polyisocyanat (2) gegebenenfalls in Gegenwart mindestens eines Kettenabbrechers (3) reagiert, so dass ein Polyurethanprepolymer entsteht, das in einer weiteren Reaktion mit mindestens einem sekundären Aminosilan (4), das kein alpha-Aminosilan ist, derart umgesetzt wird, dass der Gehalt an freiem Isocyanat kleiner als 0,1 Gew.-% bezogen auf das Gesamtgewicht des silanterminierten Polyrethans b) ist und wobei bezogen auf die Summe der Reaktanten (1), (2), (3) und (4) sich folgende Anteile ergeben:

• 1) 40 Gew.-% bis 85 Gew.-% des mindestens einer Polyols;
• 2) 10 Gew.-% bis 50 Gew.-% des mindestens einen Polyisocyanats;
• 3) 0 Gew.-% bis 25 Gew.-% des mindestens einen Kettenabbrechers;
• 4) 1 Gew.-% bis 15 Gew.-% des mindestens einen sekundären Aminosilans, das kein alpha-Aminosilan ist. reaktive Heißschmelzklebstoffzusammensetzung, bezogen auf das Gesamtgewicht der Zusammensetzung enthaltend

An object of the present invention is a reactive hot melt adhesive composition, comprising, based on the total weight of the composition

1. a) 3 wt.% to 79.999 wt.% of at least one alpha-silane-terminated organic polymer;
2. b) 20 wt.% to 96.999 wt.% of at least one silane-terminated polyurethane that is not an alpha-silane-terminated polyurethane;
3. c) 0 wt.% to 70 wt.% of at least one filler;
4. d) 0.001 wt.% to 3 wt.% of at least one silane having a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group;

wherein the at least one silane-terminated polyurethane b), which is not an alpha-silane-terminated polyurethane, is obtainable by a reaction in which at least one polyol (1) reacts with at least one polyisocyanate (2), optionally in the presence of at least one chain terminator (3), to form a polyurethane prepolymer which is further reacted with at least one secondary aminosilane (4), which is not an alpha-aminosilane, such that the content of free isocyanate is less than 0.1 wt% based on the total weight of the silane-terminated polyurethane b), and wherein the following proportions result based on the sum of the reactants (1), (2), (3) and (4):

• 1) 40% to 85% by weight of at least one polyol;
• 2) 10 wt.% to 50 wt.% of the at least one polyisocyanate;
• 3) 0 wt.% to 25 wt.% of the at least one chain breaker;
• 4) 1 wt.% to 15 wt.% of at least one secondary aminosilane, which is not an alpha-aminosilane. Reactive hot melt adhesive composition, based on the total weight of the composition containing

The reactive hot melt adhesive composition according to the invention can be reliably processed using application rollers. The processing temperature is preferably between 90 and 120 °C. At processing temperature, the reactive hot melt adhesive composition according to the invention preferably has a viscosity in the range of 1 Pa·s to 40 Pa·s and, after cooling to room temperature, exhibits a high initial tack characteristic of hot melt adhesives. The viscosity can be determined using standard methods, which are also the basis for commercially available viscometers. For example, the viscosity can be determined according to DIN 53019-1:2008-09 , DIN 53019-2:2001-02 and DIN 53019-3:2008-09 as well as DIN EN ISO 2555:2018-09 be determined.

Accordingly, the reactive hot melt adhesive composition according to the present invention is a low-viscosity, largely roller-stable, moisture-curing adhesive formulation based on alpha-silane-terminated polymers, which exhibits sufficiently high initial adhesion at room temperature for surface lamination and cures chemically quickly enough. During curing, alcohol (especially methanol, optionally also ethanol) is cleaved off via a condensation reaction, forming siloxane groups.

Preferably, the reactive hot melt adhesive composition according to the invention is isocyanate-free.

The reactive hot melt adhesive composition according to the invention contains components a), b), and d) and may also include further components. In one embodiment, the reactive hot melt adhesive composition according to the invention may not contain component c) (0 wt.% of the at least one filler). In an alternative embodiment, the reactive hot melt adhesive composition according to the invention contains component c), for example, in a proportion of at least 0.1 wt.% based on the total weight of the composition. Accordingly, 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 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 components.

The present invention relates to a reactive hot melt adhesive composition. The term "hot melt adhesive" 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 90°C and 120°C. Hot melt adhesives are applied in liquid form and then solidify, so that they are again in solid form at room temperature or have a high shear modulus. Furthermore, "reactive" hot melt adhesives are characterized by their ability to crosslink through a chemical reaction. This usually involves a reaction with water, which, for example, comes into contact with the hot melt adhesive as atmospheric moisture. These are therefore referred to as moisture-curing. This also applies to the reactive hot melt adhesive compositions of the present invention.

As component a), the reactive hot melt adhesive composition according to the invention contains at least one alpha-silane-terminated organic polymer.

In alpha-silanes, a two-stage condensation reaction of alkoxysilanes is known to occur largely autocatalytically via the donor atom (e.g., a nitrogen atom) located in the alpha position relative to the silicon atom (alpha effect). 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, this invention has demonstrated that formulations containing an alpha-silane are roller-stable for approximately 30–60 minutes at 100 °C without enclosure under typical room conditions (room temperature approximately 20–23 °C, relative humidity approximately 30–65%) and cure sufficiently quickly despite the moderate acceleration and without the use of additional co-catalysts.

Component a) of the reactive hot melt adhesive composition according to the invention comprises 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 poly They do not represent pure substances, but due to the manufacturing process occur as a mixture of substances with a characteristic distribution of substances, and therefore "a polymer" is a simplified term for this mixture of substances.

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

Alpha-silanes are characterized by the so-called alpha effect, which is described in detail in the literature, for example in Schindler, W. Silane-terminated polyethers with alpha effect. Adhaes Kleb Dicht 48, 28-32 (2004). In this effect, for example, a nitrogen atom in the alpha position to a silicon atom can make its alkoxy group(s) more reactive. Alpha-silanes are therefore more reactive towards water, among other things, which causes accelerated hydrolysis without the need for, for example, tin-containing catalysts. The hydrolysis of the silanes can occur via crosslinking to siloxanes. In this respect, the reactive hot melt adhesive compositions of the present invention represent alpha-silane-terminated hot melt adhesives that can react to form siloxanes via moisture crosslinking.

Preferably, the at least one alpha-silane-terminated organic polymer is a polymer comprising 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 represents O or N(R ⁵ ) ;
R, R ¹ , R ² and R ⁵ independently represent hydrogen or a hydrocarbon residue with 1 to 20 carbon atoms;
R ³ and R ⁴ independently represent a hydrocarbon residue with 1 to 20 carbon atoms;
a stands for 0, 1 or 2 and
“*” indicates the bond for attachment to the polymer.

More preferably, R and ^R5 represent hydrogen or an alkyl group having 1 to 6 carbon atoms, wherein the alkyl group can be straight-chain, branched, or cyclic. More preferably, R and ^R5 represent H, methyl, or ethyl, and more preferably, hydrogen or methyl.

R is particularly preferred as hydrogen when X = O. R is particularly preferred as an alkyl group with 1 to 6 carbon atoms and ^R₅ is H when X = N( ^R₅ ).

More preferably, ^R1 and ^R2 are the same. Further preferably, ^R1 and ^R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms, wherein the alkyl group can be straight-chain or branched. More preferably ^{, R1} and ^R2 are H, methyl, or ethyl; more preferably, hydrogen or methyl.

^R1 and ^R2 are particularly preferred as hydrogen.

More preferably, ^R3 and ^R4 are identical. Further preferably, ^R3 and ^R4 are alkyl groups comprising 1 to 4 carbon atoms, the alkyl group being straight-chain or branched. More preferably, ^R3 and ^R4 are methyl or ethyl.

R ³ and R ⁴ Methyl are particularly preferred.

Preferably a = 0 or 1, more preferably a = 1.

An exemplary at least one alpha-silane-terminated organic polymer is a polymer that has a variety of end groups of the formula *-OC(=O)-NH-CH ₂ -Si(CH ₃ )(OCH ₃ ) ₂ .

The numerous end groups described above terminate an organic polymer. Preferably, the organic polymer is a polyoxyalkylene, a hydrocarbon polymer, a polyurethane, a polyester, a polyamide, a polyacrylate, a polymethacrylate, or a polycarbonate. Polyoxyalkylene is preferred. Preferably, the organic polymer contains no further silane groups beyond the end groups listed above.

Preferred polyoxyalkylenes are polypropylenes, for example with a number-averaged molecular weight in the range of 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.

Component a) comprises a proportion of 3 wt.% to 79.999 wt.% based on the total weight of the composition. Preferably, the proportion is 3 to 20 wt.%, more preferably 5 to 10 wt.%.

The reactive hot melt adhesive composition according to the invention further comprises a component d). This component is at least one silane having a primary or secondary amino group or a blocked amino group that hydrolyzes to the primary or secondary amino group. Thus, component d) can have one or more, such as two, three, or four, such silanes. Preferably, component d) consists of only one component. Component d) differs from components a) to c) and is considered part of component d) only insofar as it cannot be considered one of components a) to c). In particular, the silane of component d) does not have alpha-silane groups and is of a low molecular weight or oligomeric nature and is therefore not a polymer.

The proportion of component d) is 0.001 wt.% to 3 wt.% based on the total weight of the hot melt adhesive composition according to the invention. Preferably, the proportion is 0.3 wt.% to 1.2 wt.%. More preferably, the proportion is 0.6 wt.%.

In one embodiment, the silane of component d) is at least a low molecular weight silane having a primary or secondary, preferably a primary, amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group.

The at least one low-molecular-weight silane of component d) has a primary amino group _-NH₂ . This amino group can be part of a functional group, such as an amide group -C(=O) _NH₂ , or a primary amine in the narrower sense. Advantageously, it is an amine. Low-molecular-weight silanes with a secondary amino group can also be used. Blocked aminosilanes can also be used. In this case, the blocked amino group hydrolyzes to the primary or secondary amino group, preferably to the primary amino group. ((Triethoxysilyl)propyl)methylisobutylimine is an example. Here, too, the amino group can be part of a functional group, or it can be an amino group, which is preferred. Of course, several primary amino groups can be present, in particular several primary amino groups, several secondary amino groups, and at least one primary and at least one secondary amino group. The blocked form of the primary or secondary amino group can, of course, be used instead. However, a primary or secondary amino group is preferred, and a primary amino group is even more preferred.

Advantageous low molecular weight silanes have a molecular weight in the range of 100 g/mol to 500 g/mol.

Preferred low molecular weight silanes are in DE 10 2012 200790 A1 described. Accordingly, preferred low molecular weight silanes are those containing units of the formula DSI(OR ^7' ) _g' R ^8' _(3-g') (IX), wherein
R ^7' can be the same or different and means hydrogen atom or, if applicable, substituted hydrocarbon residues,
D can be the same or different and represents a monovalent, SiC-bound residue with basic nitrogen of a primary, secondary or blocked amino group, R ^8' can be the same or different and represents a monovalent, optionally substituted SiC-bound organic residue free of basic nitrogen,
g' 1, 2 or 3, preferably 2 or 3, is.

Examples of possibly substituted hydrocarbon residues R ^7' are the examples given below for residue R ^3' .

The residues R ^7' preferably consist of hydrogen atoms and optionally substituted with halogen atoms, hydrocarbon residues with 1 to 18 carbon atoms, particularly preferably consisting of Hydrogen atom and hydrocarbon residues with 1 to 10 carbon atoms, especially methyl and ethyl residues.

Examples for remainder R ^8' are the examples given below for R ^3' .

The residue R ^8' preferably consists of hydrocarbon residues with 1 to 18 carbon atoms, optionally substituted with halogen atoms, and particularly preferably of hydrocarbon residues with 1 to 5 carbon atoms, especially the methyl residue.

Examples of residues D are residues of the formulas _H₂N ( _CH₂ ) _₃- , _H₂N ( _CH₂ ) _₂NH ( _CH₂ ) _{₃- ,} H₂N( _CH₂ ) _{₂NH(CH₂)₂NH(CH₂)₃-, H₃CNH(CH₂)₃- , C₂H₅NH ( CH₂ ) ₃- , C₃H₇NH ( CH₂ ) ₃- , C₄H₉NH ( CH₂ ) ₃- , C₅H₁₁NH ( CH₂ ) ₃- , CrH₁₃NH ( CH₂ ) ₃- , C₇H₁₅NH ( CH₂ ) ₃- , H₂} N(CH ₂ ) ₅ -, cyclo-C ₅ H ₉ NH(CH ₂ ) ₃ -, cyclo-C ₆ H ₁₁ NH(CH ₂ ) ₃ -, phenyl-NH(CH ₂ ) ₃ -, (CH ₃ ) ₂ N(CH ₂ ) ₃ -, (C ₂ H ₅ ) ₂ N(CH ₂ ) ₂ -, (C ₃ H ₇ ) ₂ NH(CH ₂ ) ₃ -, (C ₄ H ₉ ) ₂ NH(CH ₂ ) ₃ -, (C ₅ R ₁₁ ) ₂ NH(CH ₂ ) ₃ -, (C ₆ H ₁₃ ) ₂ NH(CH ₂ ) ₃ -, (C ₇ H ₁₅ ) ₂ NH(CH ₂ ) ₃ -, H ₂ N(CH ₂ )-, H ₂ N(CH ₂ ) ₂ NH(CH ₂ )-, H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₂ NH(CH ₂ )-, H ₃ CNH(CH ₂ )-, C ₂ H ₅ NH(CH ₂ )-, C ₃ H ₇ NH(CH ₂ )-, C ₄ H ₉ NH(CH ₂ )-, C ₅ H ₁₁ NH(CH ₂ )-, C ₆ H ₁₃ NH(CH ₂ )-, C ₇ H ₁₅ NH(CH ₂ )-, cyclo-C ₅ H ₉ NH(CH ₂ )-, cyclo-C ₆ H ₁₁ NH(CH ₂ )-, phenyl-NH(CH ₂ )-, (CH ₃ ) ₂ N(CH ₂ )-, (C ₂ H ₅ ) ₂ N(CH ₂ )-, (C ₃ H ₇ ) ₂ NH(CH ₂ )-, (C ₄ H ₉ ) ₂ NH(CH ₂ )-, (C ₅ H ₁₁ ) ₂ NH(CH ₂ )-, (C ₆ H ₁₃ ) ₂ NH(CH ₂ )-, (C ₇ H ₁₅ ) ₂ NH(CH ₂ )-, (CH ₃ O) ₃ Si(CH ₂ ) ₃ NH(CH ₂ ) ₃ -, (C ₂ H ₅ O) ₃ Si(CH ₂ ) ₃ NH(CH ₂ ) ₃ -, (CH ₃ O) ₂ (CH ₃ )Si(CH ₂ ) ₃ NH(CH ₂ ) ₃ - and (C ₂ H ₅ O) ₂ (CH ₃ )Si(CH ₂ ) ₃ NH(CH ₂ ) ₃ - as well Reaction products of the above-mentioned primary amino groups with compounds containing reactive double bonds or epoxide groups towards primary amino groups (blocked amino groups).

Examples of silanes of formula (IX) are _H₂N ( _CH₂ ) _₃ -Si( _OCH₃ ) _₃ , _H₂N ( _CH₂ ) _₃ -Si( _OC₂H₅ ) _₃ , _H₂N (CH₂)₃-Si( _OCH₃ ) _₂CH₃ , H₂N( _CH₂ ) _₃ -Si(OC₂H₅) _₂CH₃ , _H₂N ( _CH₂ ) _₂NH ( _CH₂ ) _₃ -Si( _OCH₃ ) _₃ , _H₂N ( _CH₂ ) _₂NH ( _CH₂ ) _{₃ - Si} ( _OC₂H₅ ) _₃ , H₂N( _CH₂ ) _₂NH ( _CH₂ ) _₃ -Si( _OCH₃ ) _₂CH₃ , _H₂N ( _CH₂ ) _₂NH ( _CH₂ ) _{₃ - Si} ( _OCH₃ ) _₂CH₃ , H₂N( _CH₂ ) _₂NH (CH₂ _{) ₃} ) ₃ -Si(OC ₂ H ₅ ) ₂ CH ₃ , H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₃ -Si(OH) ₃ , H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₃ -Si(OH) ₂ CH ₃ , H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₂ NH(CH ₂ ) ₃ Si-(OCH ₃ ) ₃ , H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₂ NH(CH ₂ ) ₃ -Si(OC ₂ H ₅ ) ₃ , cyclo-CeH ₁₁ NH(CH ₂ ) ₃ Si-(OCH ₃ ) ₃ , cyclo-C ₆ H ₁₁ NH(CH ₂ ) ₃ -Si(OC ₂ H ₅ ) ₃ , cyclo-C ₆ H ₁₁ NH(CH ₂ ) ₃ -Si(OCH ₃ ) ₂ CH ₃ , cyclo-C ₆ H ₁₁ NH(CH) ₂ ) ₃ -Si(OC ₂ H ₅ ) ₂ CH ₃ , cyclo-C ₆ H ₁₁ NH(CH ₂ ) ₃ -Si(OH) ₃ , cyclo-C ₆ H ₁₁ NH(CH ₂ ) ₃ -Si(OH) ₂ CH ₃ , Phenyl-NH(CH ₂ ) ₃ -Si(OCH ₃ ) ₃ , Phenyl-NH(CH ₂ ) ₃ -Si(OC ₂ H ₅ ) ₃ , Phenyl-NH(CH ₂ ) ₃ -Si(OCH ₃ ) ₂ CH ₃ , Phenyl-NH(CH ₂ ) ₃ -Si(OC ₂ H ₅ ) ₂ CH ₃ , Phenyl-NH(CH ₂ ) ₃ -Si(OH) ₃ , Phenyl-NH(CH ₂ ) ₃ -Si(OH) ₂ CH ₃ , HN((CH ₂ ) ₃ -Si(OCH ₃ ) ₃ ) ₂ , HN((CH ₂ ) ₃ -Si(OC ₂ H ₅ ) ₃ ) ₂ HN((CH ₂ ) ₃ -Si(OCH ₃ ) ₂ CH ₃ ) ₂ , HN((CH ₂ ) ₃ -Si(OC ₂ H ₅ ) ₂ CH ₃ ) ₂ , cyclo-C ₆ H ₁₁ NH(CH ₂ )-Si(OCH ₃ ) ₃ , cyclo-C ₆ H ₁₁ NH(CH ₂ )-Si(OC ₂ H ₅ ) ₃ , cyclo-C ₆ H ₁₁ NH(CH ₂ )-Si( _OCH3 ) _2CH3 , cyclo- _C6H11NH ( _CH2 )-Si( _{OC2H5 ) 2CH3} , cyclo- _{C6H11NH ( CH2} )-Si ₍ OH _{) 3} , cyclo _{-C6H11NH ( CH2} )-Si(OH) _{2CH3 ,} Phenyl-NH(CH ₂ )-Si(OCH ₃ ) ₃ , Phenyl-NH(CH ₂ )-Si(OC ₂ H ₅ ) ₃ , Phenyl-NH(CH ₂ )-Si(OCH ₃ ) ₂ CH ₃ , Phenyl-NH(CH ₂ )-Si(OC ₂ H ₅ ) ₂ CH ₃ , Phenyl-NH(CH ₂ )-Si(OH) ₃ and phenyl-NH(CH ₂ )-Si(OH _{)₂CH₃ and} their partial hydrolysates, wherein _H₂N ( _CH₂ ) _₂NH ( _CH₂ ) _₃ -Si( _OCH₃ ) _₃ , H₂N( _CH₂ )₂NH( _CH₂ ) _₃- Si( _OC₂H₅ ) _₃ , _H₂N (CH₂) _₂NH ( _CH₂ ) _₃ -Si( _OCH₃ ) _₂CH₃ , cyclo- _{C₆H₁₁NH} ( _CH₂ ) _{₃ -} Si _{( OCH₃ ) ₂CH₃} , cyclo- _{C₆H₁₁NH} ( _CH₂ ) _₃ -Si( _OC₂H₅ ) _{₃ ,} and cyclo- _{C₆H₁₁NH} ( _CH₂ ) _{₃ -} Si( _OCH₃ ) _{₂CH₃ ,} and their respective partial hydrolysates _, are preferred _, and _H₂N (CH₂ _{) ₃ 2} ) ₂ NH( _CH2 ) ₃ -Si( _OCH3 ) ₃ , _H2N (CH2) _2NH ( _CH2 ) ₃ -Si( _OCH3 ) _2CH3 , cyclo _{- C6H11NH} ( _CH2 ) _{3 -} Si( _OCH3 ) ₃ , cyclo- _C6H11NH ( _CH2 ) _{3 -} Si( _{OCH3 ) 2CH3 ,} and their respective partial hydrolysates are particularly preferred.

Particularly preferred examples include N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane, 3-Aminopropyltrimethoxysilane, 3-(2-Aminoethylamino)propyltriethoxysilane, N-(2-Aminoethyl)-3-aminopropylmethyldimethoxysilane, or 3-ureidopropyltrimethoxysilane. 3-Aminopropyltrimethoxysilane is especially preferred.

In a further embodiment, the silane of component d) is an oligomeric silane containing one or more amino groups, preferably with a molecular weight of more than 500 g/mol and preferably a mixture of amino group-containing alkoxy/hydroxy silanes and/or silanols as well as condensation and cocondensation products based thereon.

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

• (A) mindestens ein Aminoalkylalkoxysilan der allgemeinen Formel I NR'₂[(CH₂)₂NR']_x -Y-Si(R'')_n (OR)_3-n (I), worin Gruppen R, R' und R'' gleich oder verschieden sind und jeweils für ein Wasserstoffatom oder für eine lineare oder verzweigte Alkylgruppe mit 1 bis 8 C-Atomen stehen, Y eine bivalente Alkylengruppe aus der Reihe -CH₂-, -(CH₂)₂ -, -(CH₂)₃- oder -[CH₂CH(CH₃)CH₂]- darstellt, x gleich 0, 1 oder 2 und n gleich 0 oder 1 sind, oder
• (B) mindestens ein bis-silyliertes Alkylamin der allgemeinen Formel II (RO)_3-m(R'')_mSi-Y-[NR'(CH₂)₂]_yNR'[(CH₂)₂NR']_z-Y-Si(R'')_n(OR)_3-n (II), worin Gruppen R, R' und R'' gleich oder verschieden sind und jeweils für ein Wasserstoffatom oder für eine lineare oder verzweigte Alkylgruppe mit 1 bis 8 C-Atomen stehen, Gruppen Y gleich oder verschieden sind und Y eine bivalente Alkylengruppe aus der Reihe -CH₂-, -(CH₂)₂-, -(CH₂)₃- oder -[CH₂CH(CH₃)CH₂]- darstellt, y und z unabhängig gleich 0, 1 oder 2 sowie m und n unabhängig gleich 0 oder 1 sind, oder
• (C) mindestens ein tris-silyliertes Alkylamin der allgemeinen Formel III N[-Y-Si(R'')_n(OR)₃-_n]₃ (I), worin Gruppen R und R'' gleich oder verschieden sind und jeweils für ein Wasserstoffatom oder für eine lineare oder verzweigte Alkylgruppe mit 1 bis 8 C-Atomen stehen, Y unabhängig eine bivalente Alkylengruppe aus der Reihe -CH₂-, -(CH₂)₂-, -(CH₂)₃- oder -[CH₂CH(CH₃)CH₂ ]- darstellt und n unabhängig gleich 0 oder 1 ist, oder
• (D) mindestens zwei der zuvor genannten silylierten Alkylamine der allgemeinen Formel I, II sowie III mit einer definierten Menge an Wasser und optional unter Zusatz einer Säure hydrolysiert sowie kondensiert bzw. cokondensiert und den freien Alkohol im Wesentlichen aus dem System entfernt.

As already explained above, the oligomeric silane containing at least one or more amino groups can be a mixture that can be obtained by

• (A) at least one aminoalkylalkoxysilane of general formula I NR' ₂ [(CH ₂ ) ₂ NR'] _x -Y-Si(R'') _n (OR) _3-n (I), wherein groups R, R' and R'' are the same or different and each represents a hydrogen atom or a linear or branched alkyl group with 1 to 8 C atoms, Y represents a bivalent alkylene group from the series -CH ₂ -, -(CH ₂ ) ₂ -, -(CH ₂ ) ₃ - or -[CH ₂ CH(CH ₃ )CH ₂ ]-, x is equal to 0, 1 or 2 and n is equal to 0 or 1, or
• (B) at least one bis-silylated alkylamine of general formula II (RO) _3-m (R'') _m Si-Y-[NR'(CH ₂ ) ₂ ] _y NR'[(CH ₂ ) ₂ NR'] _z -Y-Si(R'') _n (OR) _3-n (II), wherein groups R, R' and R'' are the same or different and each represents a hydrogen atom or a linear or branched alkyl group with 1 to 8 carbon 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 equal to 0, 1 or 2 and m and n are independently equal to 0 or 1, or
• (C) at least one tris-silylated alkylamine of general formula III N[-Y-Si(R'') _n (OR) ₃ - _n ] ₃ (I), wherein groups R and R'' are the same or different and each represent a hydrogen atom or a linear or branched alkyl group with 1 to 8 C atoms, Y independently represents a bivalent alkylene group from the series -CH ₂ -, -(CH ₂ ) ₂ -, -(CH ₂ ) ₃ - or -[CH ₂ CH(CH ₃ )CH ₂ ]- and n independently is equal to 0 or 1, or
• (D) at least two of the aforementioned silylated alkylamines of general formula I, II and III are hydrolyzed and condensed or co-condensed with a defined amount of water and optionally with the addition of an acid, and the free alcohol is substantially removed from the system.

Here, mono-silylated amines are defined as those of formula I. Oligo-silylated amines are defined in particular as those bearing two or more 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 exist in cyclized form.

In the preparation of the mixture, aminoalkylalkoxysilanes of general formula I are preferably used. _H₂N ( _CH₂ ) _₃Si ( _OCH₃ ) _₃ (AMMO), H ₂ N(CH ₂ ) ₃ Si(OC ₂ H ₅ ) ₃ (AMEO), H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₃ Si(OCH ₃ ) ₃ (DAMO), H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₂ NH(CH ₂ ) ₃ Si(OCH ₃ ) ₃ (TRIAMO), as well as, if applicable, corresponding cyclic compounds.
Compounds according to Formula II are preferred (H ₃ CO) ₃ Si(CH ₂ ) ₃ NH(CH ₂ ) ₃ Si(OCH ₃ ) ₃ (Bis-AMMO), (H ₅ C ₂ O) ₃ Si(CH ₂ ) ₃ NH(CH ₂ ) ₃ Si(OC ₂ H ₅ ) ₃ (Bis-AMEO), (H ₃ CO) ₃ Si(CH ₂ ) ₃ NH(CH ₂ ) ₂ NH(CH ₂ ) ₂ NH(CH ₂ ) ₃ Si(OCH ₃ ) ₃ (Bis-DAMO), (H ₃ CO) ₃ Si(CH ₂ ) ₃ NH(CH ₂ ) ₂ NH(CH ₂ ) ₂ NH(CH ₂ ) ₂ NH(CH ₂ ) ₂ NH(CH ₂ ) ₂ Si(OCH ₃ ) ₃ (Bis-TRIAMO),
as compounds according to Formula III N[CH ₂ ) ₃ Si(OCH ₃ ) ₃ ] ₃ (Tris-AMMO), N[CH ₂ ) ₃ Si(OC ₂ H ₅ ) ₃ ] ₃ (Tris-AMEO).

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 means methyl, ethyl, n-propyl or n-butyl as well as alkoxy methoxy or ethoxy, a preferred selection of the component (B) can be from the series Bis-AMMO, Bis-AMEO, Bis-DAMO and component (C) from the series Tris-AMMO, Tris-AMEO.

Mixtures containing compounds of general formulas I, II, and/or III can also be advantageously used to prepare the mixture. Such usable mixtures can also contain so-called ancondensation products of said aminoalkoxysilanes. Ancondensation products or reaction products of aminoalkoxysilanes of general formulas I, II, and/or III are suitably understood to be dimeric, trimeric, tetrameric, or higher oligomeric products, which generally arise from condensation or cocondensation and/or pre-hydrolysis 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 silanol. Likewise, compounds of general formula II can exist in cyclic or bicyclic form and be used as such.

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 ancondensation products.

Preferably, the reaction, in particular hydrolysis as well as condensation or co-condensation, is carried out at a temperature < 100°C, preferably from 10 to 80°C, particularly preferably from 15 to 60°C, and especially from 20 to 50°C.

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, the water added thereby being added to the amount of water required for the targeted hydrolysis of the alkoxysilanes according to the invention. However, the acid can also be added after the preparation of the mixture, preferably to a pH of 2 to 6, and particularly 3 to 5.

In particular, the mixture is prepared by distillation of the product mixture from the reaction; that is, the components that are otherwise readily volatile under ambient conditions, especially the hydrolysis alcohol and any added solvent or diluent, are preferably distilled off from the resulting product mixture under gentle heating and reduced pressure. If necessary, the amount of volatile components removed from the system can be replaced by the same volume of water and/or acid.

The mixture preferably contains organic or inorganic acid, wherein the degree of neutralization of the aminoalkyl and oligo-silylated aminoalkyl groups is suitably 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 be determined according to DIN 16945:1989-03 be performed.

Preferably, the acid used is 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, according to chemical understanding, at least partially present as a cationic amine mixture, i.e., that a composition used according to the invention preferably has a content of acid and/or a corresponding salt of acid and one of the present amino functional compounds.

The mixture can 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 is determined, for example, according to DIN 530195 (Parts 1 to 3) as well as DIN EN ISO 2555 can be determined.

The reactive hot melt adhesive composition according to the invention can contain one or more fillers c) and optionally one or more further components.

Accordingly, the composition may contain one filler or two, three, or more different fillers. If component c) is present, its proportion, based on the total weight of the composition, is up to 70 wt.%, preferably up to 35 wt.%. Fillers are known to those skilled in the art. An example of a filler is calcite. Other examples include calcium carbonate, such as chalk, or corundum, such as aluminum oxide. The use of fillers can prevent or reduce stringing during processing of the adhesive composition.

Furthermore, one or more, for example one, two or three, additional components may be included. Preferably, however, the reactive hot melt adhesive composition according to the invention does not contain acrylic resins, such as those found in WO 2021/214290 A1 and WO 2023/066902 A1 can be used. Accordingly, the reactive hot melt adhesive composition according to the invention is preferably free of one or more acrylate resin-based polymers that are not silane-terminated organic polymers.

The hot melt adhesive composition according to the invention can contain at least one silicone resin, such as a phenyl silicone resin. Silicone resins are used, for example, in DE 10 2013 213 835 A1 described. Within the scope of the present invention, a silicone resin is considered an additional component, unless it is already one of the components described above.

Accordingly, possible silicone resins contain according to DE 10 2013 213 835 A1 Units of the formula R ^3' _c' (R ^4' O) _d' R ^5' _e' SiO _{(4-c'-d'-e')/2} (II), where
R ^3' may be the same or different and signifies a hydrogen atom, a monovalent, SiC-bonded, optionally substituted aliphatic hydrocarbon residue or a divalent, optionally substituted, aliphatic hydrocarbon residue bridging two units of formula (II),
R ^4' can be the same or different and represents a hydrogen atom or a monovalent, possibly substituted, hydrocarbon residue,
R ^5' can be the same or different and represents a monovalent, SiC-bonded, optionally substituted aromatic hydrocarbon residue,
c' 0, 1, 2 or 3 is,
d' 0, 1, 2 or 3, preferably 0, 1 or 2, particularly preferably 0 or 1, is and
e' 0, 1 or 2, preferably 0 or 1, is,
provided that the sum of c' + d' + e' is less than or equal to 3, in at least one unit e' is different from 0 and in at least 40% of the units of formula (II) the sum c' + e' is equal to 0 or 1.

Suitable silicone resins preferably consist of at least 90 wt.% units of formula (II), particularly preferably exclusively of units of formula (II).

Examples of R3 ^' groups are alkyl groups, such as methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, and tert-pentyl groups; hexyl groups, such as n-hexyl; heptyl groups, such as n-heptyl; octyl groups, such as n-octyl, isooctyl, and 2,2,4-trimethylpentyl; nonyl groups, such as n-nonyl; decyl groups, such as n-decyl; dodecyl groups, such as n-dodecyl; and octadecyl groups, such as n-octadecyl. Cycloalkyl groups, such as cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl groups; alkenyl groups, such as vinyl, 1-propenyl and 2-propenyl groups; aryl groups, such as phenyl, naphthyl, anthryl and phenanthryl groups; alkaryl groups, such as o-, m-, p-tolyl groups; xylyl groups and ethylphenyl groups; and aralkyl groups, such as benzyl, o- and β-phenylethyl groups.

Examples of substituted R ^3' groups are haloalkyl groups, such as the 3,3,3-trifluoro-n-propyl group, the 2,2,2,2',2',2'-hexafluoroisopropyl group and the heptafluoroisopropyl group, and haloaryl groups, such as the o-, m- and p-chlorophenyl group.

Preferably, R ^3' is a monovalent hydrocarbon residue with 1 to 6 carbon atoms, optionally substituted with halogen atoms, and particularly preferably an alkyl residue with 1 or 2 carbon atoms, especially a methyl residue. However, R ^3' can also be a divalent aliphatic residue linking two silyl groups of formula (II), such as alkylene residues with 1 to 10 carbon atoms, like methylene, ethylene, propylene, or butylene residues.

Preferably, however, residue R ^3' is a monovalent SiC-bonded aliphatic hydrocarbon residue with 1 to 18 carbon atoms, optionally substituted with halogen atoms, and particularly preferably an aliphatic hydrocarbon residue with 1 to 6 carbon atoms, especially the methyl residue.

Examples for residue R ^4' are hydrogen atoms or the examples given for residue R ^3' .

Preferably, the residue R ^4' is a hydrogen atom or optionally alkyl residues substituted with halogen atoms with 1 to 10 carbon atoms, particularly preferably alkyl residues with 1 to 4 carbon atoms, especially the methyl and ethyl residues.

Examples of residues R ^5' are the aromatic residues listed above for R ^3' .

Preferably, the residue R ^5' is a SiC-bonded aromatic hydrocarbon residue with 1 to 18 carbon atoms, optionally substituted with halogen atoms, such as ethylphenyl, toluyl, xylyl, chlorophenyl, naphtyl or styryl residues, particularly preferably the phenyl residue.

Silicone resins are preferably used in which at least 90% of all residues R ^3' represent methyl residues, at least 90% of all residues R ^4' represent methyl, ethyl, propyl or isopropyl residues and at least 90% of all residues R ^5' represent phenyl residues.

Preferably, silicone resins are used which have at least 40%, particularly preferably at least 60%, units of formula (II) in which c' is equal to 0, in each case based on the total number of units of formula (II).

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

Preferably, silicone resins are used which, based on the total number of units of formula (II), at least 20%, and particularly preferably at least 40%, have units of formula (II) in which e' represents the value 1. Silicone resins may be used which exclusively have units of formula (II) in which e' is equal to 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.

Preferably, silicone resins are used which, based 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.

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%, and particularly preferably at least 40%, units of formula (II) in which e' represents the value 1 and c' represents the value 0. Preferably, at most 40%, and particularly preferably at most 70%, of all units of formula (II) have a d' other than 0.

In a further 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%, units of formula (II) in which e' represents the value 1 and c' represents the value 0, and which also comprise at least 1%, preferably at least 10%, units of formula (II) in which c' represents 1 or 2, preferably 1, and e' represents 0.

Examples of silicone resins are organopolysiloxane resins, which consist essentially, preferably exclusively, of (Q) units of the formulas SiO₄ _/2 , Si(OR₄ ^' )O₃ _/2 , Si(OR₄ ^' ) _{₂O₂/ 2} and Si( ^OR₄ ) _{₃O₁ /2} , (T) units of the formulas PhSiO₃ _/2 , PhSi( ^OR₄ ) _{O₂ /2} , PhSi( ^OR₄ ) _₂O₁/ 2, _MeSiO₃/ ² , MeSi(OR₄)O₂ _/2 and MeSi( ^OR₄ ) _{₂O₁ /} 2, (D) units of the formulas _{Me₂SiO₂ /2} , _Me₂Si ( ^OR₄ )O₁ _{/ 2} , Ph₂SiO₂ _/ 2 and _Ph₂Si ( ^OR₄ )O₁ _/2 , MePhSiO₄ _2/2 and MePhSi(OR ^4' )O _1/2 as well as (M) units of the formula Me ₃ SiO _1/2 , wherein Me represents a methyl group, Ph represents a phenyl group and R ^4' represents a hydrogen atom or optionally halogen-substituted alkyl groups with 1 to 10 carbon atoms, particularly preferably around a hydrogen atom or alkyl groups with 1 to 4 carbon atoms, where the resin contains 0-2 mol (Q) units, 0-2 mol (D) units and 0-2 mol (M) units per mol (T) units.

Preferred examples of silicone resins are organopolysiloxane resins consisting essentially, preferably exclusively, of T-units of the formulas PhSiO _3/2 , PhSi(OR ⁴ )O _2/2 and PhSi(OR ⁴ ) ₂ O _1/2 , T-units of the formulas MeSiO _3/2 , MeSi(OR ⁴ )O _2/2 and MeSi(OR ⁴ ) ₂ O _1/2 , and D-units of the formulas Me ₂ SiO _2/2 and Me ₂ Si(OR ^4' )O _1/2 , wherein Me represents a methyl group, Ph a phenyl group, and R ^4' a hydrogen atom or optionally halogen-substituted alkyl groups with 1 to 10 carbon atoms, particularly preferably around a hydrogen atom or alkyl groups with 1 to 4 carbon atoms, with a molar ratio of (T)- to (D)-units of 0.5 up to 2.0.

Among these examples, silicone resins are particularly preferred whose units of formula (II) are formed to at least 50%, preferably at least 70%, in particular at least 85% from T-units of formulas PhSiO _3/2 , PhSi(OR ⁴ )O _2/2 , PhSi(OR ⁴ ) ₂ O _1/2 , Me SiO _3/2 , MeSi(OR ⁴ )O _2/2 and MeSi(OR ⁴ ) ₂ O _1/2 , wherein these silicone resins contain at least 30%, preferably at least 40%, in particular at least 50% T-units of formulas PhSiO _3/2 , PhSi(OR ⁴ )O _2/2 and PhSi(OR ^4' ) ₂ O _1/2 and at least 10%, preferably at least 15%, in particular at least 20% T-units of MeSiO _3/2 , MeSi(OR ⁴ )O _2/2 and MeSi(OR ⁴ ) ₂ O _1/2 contained.

Preferably, the silicone resins have a mean molar mass (number-average) Mn of at least 500 g/mol and particularly preferably of at least 600 g/mol. The mean molar mass Mn is preferably at most 400,000 g/mol, particularly preferably at most 100,000 g/mol, and especially at most 50,000 g/mol.

Such silicone resins can be both solid and liquid at 23°C and 1000 hPa, with silicone resins preferably being liquid.

The silicone resins are commercially available products (for example, Silres® IC 368 from Wacker Chemie (DE)) or they can be produced using methods common in silicon chemistry.

Furthermore, the reactive hot melt adhesive composition according to the present invention can additionally contain at least one tackifier. One tackifier or, for example, two or three different tackifiers can be used. The proportion is advantageously up to 65 wt.%, for example from 0.01 wt.% to 65 wt.%, and more preferably in the range of up to 15 wt.%, for example from 0.01 wt.% to 15 wt.%, based on the total weight of the composition.

Furthermore, the reactive hot melt adhesive composition according to the present invention can additionally contain at least one stabilizer. This stabilizer can be one, two, three, or four. Stabilizers are known to those skilled in the art. They can include, among others, antioxidants, sterically hindered amines as light stabilizers, UV absorbers, or water scavengers. The proportion is advantageously up to 2 wt.%, for example, from 0.01 wt.% to 2 wt.%, and more preferably in the range of 0.4 wt.% to 0.8 wt.%, based on the total weight of the composition.

The reactive hot melt adhesive composition according to the invention further comprises a component b). This component is at least one silane-terminated polyurethane that is not an alpha-silane-terminated polyurethane. Thus, component b) can comprise one or more, such as two, three, or four, such silane-terminated polyurethanes. Preferably, component b) consists of only one component.

The proportion of component b) is 20 wt.% to 96.999 wt.% based on the total weight of the hot melt adhesive composition according to the invention. Preferably, the proportion is 50 wt.% to 90 wt.%. More preferably, the proportion is 61 wt.%.

• 1) 40 Gew.-% bis 85 Gew.-% des mindestens einer Polyols;
• 2) 10 Gew.-% bis 50 Gew.-% des mindestens einen Polyisocyanats;
• 3) 0 Gew.-% bis 25 Gew.-% des mindestens einen Kettenabbrechers;
• 4) 1 Gew.-% bis 15 Gew.-% des mindestens einen sekundären Aminosilans, das kein alpha-Aminosilan ist.

The at least one silane-terminated polyurethane (b), which is not an alpha-silane-terminated polyurethane, is obtainable by a reaction in which at least one polyol (1) reacts with at least one polyisocyanate (2), optionally in the presence of at least one chain terminator (3), to form a polyurethane prepolymer which is further reacted with at least one secondary aminosilane (4), which no alpha-aminosilane is reacted in such a way that the content of free isocyanate is less than 0.1 wt.%, preferably less than 0.001 wt.%, based on the total weight of the silane-terminated polyurethane b) and wherein the following proportions result based on the sum of the reactants (1), (2), (3) and (4):

• 1) 40% to 85% by weight of at least one polyol;
• 2) 10 wt.% to 50 wt.% of the at least one polyisocyanate;
• 3) 0 wt.% to 25 wt.% of the at least one chain breaker;
• 4) 1 wt.% to 15 wt.% of at least one secondary aminosilane that is not an alpha-aminosilane.

Preferably, the following proportions result with respect to the sum of reactants (1), (2), (3) and (4): Preferably, the proportion of the at least one polyol is 50 wt.% to 70 wt.%. Preferably, the proportion of the at least one polyisocyanate is 25 wt.% to 40 wt.%. Preferably, the proportion of the at least one chain terminator is 2 wt.% to 10 wt.%. Preferably, the proportion of the at least one secondary aminosilane, which is not an alpha-aminosilane, is 5 wt.% to 10 wt.%.

Preferably, the isocyanate content of the polyurethane prepolymer is between 0.5 wt.% and 5 wt.%, preferably between 0.8 wt.% and 1.5 wt.%.

Component b) is obtained from the reaction in which at least one polyol (1) reacts with at least one polyisocyanate (2) optionally in the presence of at least one chain terminator (3) to form a polyurethane prepolymer which is further reacted with at least one secondary aminosilane (4) which is not an alpha-aminosilane.

The reaction uses at least one polyisocyanate. The prefix "poly" indicates that at least two (diisocyanate) isocyanate groups are present in the molecule. More than two, such as three, four, five, or a plurality of more than five isocyanate groups, are also possible. Preferably, the at least one polyisocyanate (2) is at least one diisocyanate. One or more, such as two, three, or four polyisocyanates, can be used.

Suitable diisocyanates include methylenediphenyl diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, diisocyanatodicyclohexylmethane, isophorone diisocyanate, toluene diisocyanate, and naphthylene diisocyanate, optionally including their isomers and homologs. Methylenediphenyl diisocyanates (MDI) are preferred, with the isomer diphenylmethane-2,4'-diisocyanate or a mixture with other MDI isomers being particularly preferred, wherein the proportion of diphenylmethane-2,4'-diisocyanate is preferably at least 45%. The advantage of using a high content of diphenylmethane-2,4'-diisocyanate is due to a shorter chain structure during prepolymerization. A short-chain prepolymer leads to lower viscosities, and the products formulated with it are thus easier to process. Chemical modifications or oligomeric addition or condensation products of the aforementioned diisocyanates may also be suitable. Examples include carbodiimide-linked diisocyanates, commercially available under the trade name Desmodur® CD-S, and uretdione-linked diisocyanates, commercially available under the trade name Desmodur® N 3400. The use of mixtures of these diisocyanates with each other, as well as mixtures with isomers and higher-functionality homologs, such as a mixture of diphenylmethane-4,4'-diisocyanate with isomers and higher-functionality homologs (polymeric MDI), commercially available under the trade name Desmodur® VK 5, is also conceivable.

The reaction uses at least one polyol. The prefix "poly" indicates that the molecule contains at least two hydroxyl groups (diols). More than two hydroxyl groups are also possible, such as three, four, five, or even more than five. One or more polyols, such as two, three, or four, can be used.

Suitable polyols include polyether polyols, hydroxyl-functional polyacrylates, and monomeric polyols such as 1,4-butanediol and mixtures of these polyols. Polypropylene glycols, polybutylene glycols, and polyether polyols produced from ethylene and propylene oxides are preferred among the polyether polyols. A small proportion of polyethylene glycols or other polyols, up to a mass fraction of 15%, is also conceivable. Polyether polyols produced via both KOH- and dimetal complex-catalyzed polymerization can be used. The molecular weight of the polyether polyols can be up to 16,000 g/mol. Particularly preferably, the average molecular weight is above 60%, more preferably above 80%, and most preferably above 90% of the polyether polyols used, with a molecular weight below 2,000 g/mol. The use of relatively low-molecular-weight polyols results in the formation of numerous polyurethane units during prepolymerization, which interact with each other, among other things, via hydrogen bonds. This interaction is more pronounced at room temperature than at processing temperature. The products formulated in this way thus exhibit relatively high initial strength at room temperature and low viscosity during processing.

Polyacrylates with reactive functional hydroxyl groups, types with an OH number of less than 10 mg KOH/g, which are commercially available, for example, under the trade name Dianal MB-2876, have proven to be advantageous.

The polyols used have an average functionality of less than 3. The acid number of the polyols used is preferably below 8 mg KOH/g, particularly preferably below 0.1 mg KOH/g (ASTM D4662).

The reaction may involve the use of at least one chain terminator. It can be one or more, such as two, three, or four chain terminators.

Suitable chain terminators are compounds that possess a functional group capable of reacting with an isocyanate group. A hydroxyl group is preferred as the functional group. Examples of suitable chain terminators are dipropylene glycol monomethyl ether and propylene glycol 1-phenyl ether.

The reaction uses at least one secondary aminosilane that is not an alpha-aminosilane. It can be one or more aminosilanes, such as two, three, or four.

For example, N-cyclohexyl-3-aminopropyltrimethoxysilane, which is commercially available under the trade name Geniosil® GF 92, is suitable as a secondary aminosilane. In particular, silanes containing secondary amine groups, such as those described as component d) herein, are suitable.

1. (a) Herstellen des mindestens einen silanterminierten Polyurethans b);
2. (b) Mischen des mindestens einen silanterminierten Polyurethans b) aus Schritt (a) mit dem mindestens einen alpha-Silan-terminierten organischen Polymer (a);
3. (c) Gegebenenfalls Zugeben des mindestens einen Füllstoffes c); und
4. (d) Zugeben des mindestens einen Silans d), das eine primäre oder sekundäre Aminogruppe oder eine geblockte Aminogruppe, die zu der primären oder sekundären Aminogruppe hydrolysiert, aufweist.

Another object of the present invention is a method for producing a reactive hot melt adhesive composition according to the invention, comprising steps

1. (a) Production of at least one silane-terminated polyurethane b);
2. (b) Mixing the at least one silane-terminated polyurethane (b) from step (a) with the at least one alpha-silane-terminated organic polymer (a);
3. (c) If necessary, adding at least one filler c); and
4. (d) Addition of at least one silane d), which has a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group.

Finally, another object of the present invention is a method for surface lamination comprising the step of applying a reactive hot melt adhesive composition according to the invention to a substrate, preferably to a substrate with a polar surface, using an application roller.

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 surface lamination process in which the reactive hot melt adhesive composition according to the present invention is applied to a substrate using an application roller.

Surprisingly, it has been shown that the coating can be cleaned using a roller coating machine even after the roller stability period has been exceeded, i.e., when the binder exhibits noticeable stringiness during processing, which determines the coating appearance.

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.

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

• - Isocyanatfreiheit,
• - gutes Haftungsspektrum, insbesondere auf Metallen, Glas und anderen Werkstoffen
• - Kein Aufschäumen durch CO₂-Bildung.

The following advantages are particularly evident:

• - Isocyanate-free,
• - Good adhesion spectrum, especially on metals, glass and other materials
• - No foaming due to _CO2 formation.

The present invention is explained in more detail with reference to the following examples, although the invention is not limited to these embodiments.

Examples

Example 1a: Synthesis of a polyurethane prepolymer according to the invention.

50 g of dipropylene glycol monomethyl ether are placed in a planetary mixer with a dissolver agitator together with 461 g of Caradol ED 260-02 (polypropylene glycol 400) and 80 g of Caradol ED56-200 (polypropylene glycol 2000) and heated to 100 °C. Then, 349 g of Lupranat® MIS (mixture of 2,4'- and 4,4'-diphenylmethane diisocyanate) is added and stirred under vacuum at 50 mbar until the mixture is homogeneous and has a residual isocyanate content of approximately 1% (see Table 1a). Table 1a: Composition of the polyurethane prepolymer precursor raw material Manufacturer Crowd Dipropylene glycol monomethyl ether (chain breaker) Shell Chemicals Europe BV 50 g Caradol ED 260-02 (polypropylene glycol 400) Shell Chemicals Europe BV 461g CARADOL ED56-200 (polypropylene glycol 2000) Shell Chemicals Europe BV 80 g Lupranat® MIS (mixture of 2,4'- and 4,4'-diphenylmethane dicyanate) BASF SE 349 g

Example 1b: Synthesis of a silane-terminated polyurethane according to the invention

940 g of polyurethane prepolymer from example 1a are placed on the surface, 60 g of Geniosil® GF 92 are added and stirred at 800 mbar for 5 minutes (see Table 1b). Table 1b: Composition of the silane-terminated polyurethane VP99191133. raw material Manufacturer Crowd Wording from example 1a Kleiberite 940 g Geniosil® GF 92 (secondary aminosilane) Wacker 60 g

Example 1c: Production of an adhesive formulation according to the invention

608 g of silane-terminated polyurethane from Example 1b and 80 g of Geniosil® STP-E 10 are mixed in a planetary mixer with a butterfly agitator under vacuum (50 mbar) at 100 °C. Then, 300 g of Calcit MX 30 are added portionwise while stirring, and the mixture is degassed under vacuum at 50 mbar for 10 minutes. Finally, 4 g of Dynasylan® 1146 are added to this mixture and stirred at 800 mbar for 5 minutes (see Table Ic). Table 1c: Composition and physicochemical properties of the silane-terminated polyurethane hot melt adhesive raw material Manufacturer Wording from example 1b Kleiberite 608 g Geniosil® STP-E 10 (alpha-silane component) Wacker 80 g Calcite MX 30 (filler) SH Minerals GmbH 300 g Dynasilan® 1146 (Aminosilane component) Evonik 4 g Irganox® 245 (antioxidant) BASF SE 8 g Viscosity (80°C, 3.4 s ^-1 ) 266 Pa·s Viscosity (100°C, 3.4 s ^-1 ) 53 Pa·s Viscosity (120°C, 3.4 s ^-1 ) 16 Pa·s

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• WO 03/055929 A1 [0004]
• WO 01/40342 A1 [0004]
• WO 03/033562 A1 [0004]
• WO 03/006521 A1 [0004]
• WO 2004/005420 A1 [0005]
• WO 2007/074143 A1 [0008]
• WO 2013/026654 A1 [0009]
• DE 10 2013 213 835 A1 [0009, 0074, 0075]
• WO 2011/087741 A2 [0010]
• WO 2021/214290 A1 [0012, 0073]
• WO 2023/066902 A1 [0012, 0073]
• DE 10 2012 200790 A1 [0049]
• DE 10 2007 040 802 A1 [0058]

Cited non-patent literature

• DIN 53019-1:2008-09 [0022]
• DIN 53019-2:2001-02 [0022]
• DIN 53019-3:2008-09 [0022]
• DIN EN ISO 2555:2018-09 [0022]
• DIN 16945:1989-03 [0068]
• DIN 530195 [0070]
• DIN EN ISO 2555 [0070]

Claims (21)

Reactive hot melt adhesive composition, based on the total weight of the composition, containing: a) 3 wt.% to 79.999 wt.% of at least one alpha-silane-terminated organic polymer; b) 20 wt.% to 96.999 wt.% of at least one silane-terminated polyurethane that is not an alpha-silane-terminated polyurethane; c) 0 wt.% to 70 wt.% of at least one filler; d) 0.001 wt.% to 3 wt.% of at least one silane having a primary or secondary amino group or a blocked amino group that hydrolyzes to the primary or secondary amino group; wherein the at least one silane-terminated polyurethane b), which is not an alpha-silane-terminated polyurethane, is obtained by a reaction in which at least one polyol (1) reacts with at least one polyisocyanate (2), optionally in the presence of at least one chain terminator (3), to form a polyurethane prepolymer, which is further reacted with at least one secondary aminosilane (4), which is not an alpha-aminosilane, such that the free isocyanate content is less than 0.1 wt% based on the total weight of the silane-terminated polyurethane b), and wherein, based on the sum of the reactants (1), (2), (3), and (4), the following proportions are obtained: 1) 40 wt% to 85 wt% of the at least one polyol; 2) 10 wt% to 50 wt% of the at least one polyisocyanate; 3) 0 wt% to 25 wt% of the at least one chain terminator; 4) 1 wt.% to 15 wt.% of at least one secondary aminosilane that is not an alpha-aminosilane. Reactive hot melt adhesive composition according to Claim 1 , characterized in that the composition is free of one or more acrylate resin-based polymers that are not alpha-silane-terminated organic polymers. Reactive hot melt adhesive composition according to Claim 1 or 2 , characterized in that the composition comprises 50 wt.% to 90 wt.% of at least one silane-terminated polyurethane that is not an alpha-silane-terminated polyurethane. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 3 , characterized in that the composition contains 5 wt.% to 10 wt.% of the at least one alpha-silane-terminated organic polymer. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 4 , characterized in that the composition comprises 0.3 wt.% to 1.2 wt.% of at least one silane comprising a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 5 , characterized in that the composition contains one or more fillers and optionally one or more further components. Reactive hot melt adhesive composition according to Claim 6 , characterized in that the proportion of at least one filler is up to 70 wt.%, preferably up to 35 wt.%. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 7 , characterized in that at least one component is a stabilizer, preferably with up to 2 wt.%, more preferably 0.4 to 0.8 wt.%, based on the composition. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 8 , characterized in that at least one component is a resin, for example a sticky resin, preferably with up to 65 wt.%, more preferably up to 15 wt.%, based on the composition. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 9 , characterized in that the at least one polyisocyanate (2) is a diisocyanate. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 10 , characterized in that the isocyanate content of the polyurethane prepolymer is between 0.5 wt.% and 5 wt.%, preferably between 0.8 wt.% and 1.5 wt.%. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 11 , characterized in that the proportion of at least one polyol is 50 wt.% to 70 wt.%. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 12 , characterized in that the proportion of at least one polyisocyanate is 25 wt.% to 40 wt.%. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 13 , characterized in that the proportion of the at least one chain breaker is 2 wt.% to 10 wt.%. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 14 , characterized in that the proportion of the at least one secondary aminosilane, which is not an alpha-aminosilane, is 5 wt.% to 10 wt.%. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 15 , characterized in that the at least one alpha-silane-terminated organic polymer has 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 , where X stands for O or N(R ⁵ ); R, R ¹ , R ² and R ⁵ independently stand for hydrogen or a hydrocarbon residue with 1 to 20 carbon atoms; R ³ and R ⁴ independently stand for a hydrocarbon residue with 1 to 20 carbon atoms; a stands for 0, 1 or 2 and “*” denotes the bond for attachment to the polymer. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 16 , characterized in that the organic polymer of the at least one alpha-silane-terminated organic polymer is a polyoxyalkylene, a hydrocarbon polymer, a polyurethane, a polyester, a polyamide, a polyacrylate, a polymethacrylate or a polycarbonate. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 17 , characterized in that the at least one silane, which has a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group, is a low molecular weight silane, preferably with a molecular weight in the range of 100 to 500 g/mol. Reactive hot melt adhesive composition according to one or more of the Claims 1 until 18 , characterized in that the at least one silane, which has a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group, is an oligomeric silane containing one or more amino groups, preferably with a molecular weight of more than 500 g/mol and preferably a mixture of amino group-containing alkoxy/hydroxy silanes and/or silanols as well as condensation and cocondensation products based thereon. Method for producing a reactive hot melt adhesive composition according to one or more of the Claims 1 until 19 , comprising the steps (a) producing at least one silane-terminated polyurethane b), which is not an alpha-silane-terminated polyurethane, by a reaction in which at least one polyol (1) reacts with at least one polyisocyanate (2), optionally in the presence of at least one chain terminator (3), to form a polyurethane prepolymer, which is further reacted with at least one secondary aminosilane (4), which is not an alpha-aminosilane, such that the free isocyanate content is less than 0.1 wt% based on the total weight of the silane-terminated polyurethane b), wherein, based on the sum of the reactants (1), (2), (3) and (4), the following proportions are obtained: 1) 40 wt% to 85 wt% of the at least one polyol; 2) 10 wt% to 50 wt% of the at least one polyisocyanate; 3) 0 wt% to 25 wt% of the at least one chain terminator; 4) 1 wt% to 15 wt% of the at least one secondary aminosilane that is not an alpha-aminosilane; (b) mixing the at least one silane-terminated polyurethane (b) from step (a) with the at least one alpha-silane-terminated organic polymer (a); (c) optionally adding the at least one filler (c); and (d) adding the at least one silane (d) having a primary or secondary amino group or a blocked amino group which hydrolyzes to the primary or secondary amino group. A surface lamination process comprising the step of applying a reactive hot melt adhesive composition according to one of the Claims 1 until 19 on a substrate using an application roller.