Improved method for pre-fixing and bonding components

Abstract

The invention relates to a method for pre-fixing and bonding two components T1 and T2, comprising the steps of: a) providing a one-component moisture-curing adhesive K and an accelerator composition B, said accelerator composition B comprising between 10 and 80 wt.-% of water; b) preparing an accelerated adhesive KB1 by mixing the adhesive K and the aqueous accelerator composition B to an accelerated adhesive KB1, wherein the accelerated adhesive KB1 comprises between 5 and 20 vol.-% of the accelerator composition B, and then applying the accelerated adhesive KB1 to the first component T1; c) preparing an optionally accelerated adhesive KB2 by optionally mixing the adhesive K and the aqueous accelerator composition B to an optionally accelerated adhesive KB2, wherein the optionally accelerated adhesive KB2 comprises less than 5 vol.-% of the accelerator composition B, and then applying the optionally accelerated adhesive KB2 to the first component T1; wherein steps b) and c) are performed in any order, and the amount of the accelerated adhesive KB1 applied to the component T1 is less than the amount of the optionally accelerated adhesive KB2 applied to the first component T1; d) joining the second component T2 in bonding position to form a joining seam T12, which joins the two components T1 and T2 by means of the accelerated adhesive KB1 and the optionally accelerated adhesive KB2. The method according to the invention enables the pre-fixing and bonding of components to be bonded with a single adhesive without the need for additional pre-fixing and without damaging the resulting bond by adhesives which cure with non-uniform mechanical properties. A rapid and better bonding can thus be achieved, which can also be carried out at lower cost.

Description

Technical Field

[0001] The present invention relates to a method for pre-fixing and bonding components, wherein the components are bonded using a moisture-curing composition. Background Technology

[0002] In industrial manufacturing, adhesives have long been used to join components of products. Compared to other joining techniques (such as bolts or welding), adhesives have the advantage of being more widely used than welding, and because they do not require drilling, they do not cause mechanical weakening or cosmetic damage to the product.

[0003] In terms of efficient manufacturing processes, it is sometimes necessary to pre-fix the components to be joined after the adhesive is introduced into the bonding joint, so that the adhesive can cure or build up sufficient strength to prevent the components from slipping. This method allows for rapid temporary fixing, resulting in shorter production cycles and allowing for a wider selection of adhesives.

[0004] Mechanical pre-fixation using suitable devices is not feasible in all cases and has the following disadvantages: complex and expensive fixing devices must be used, which in turn prolongs the bonding process and thus the entire manufacturing process. In the case of large parts, complete clamping devices must be built, which also occupies a large amount of space in production, preventing it from being used for other processes. Therefore, pre-fixation-bonding is commonly used in modern industrial manufacturing. Very fast-curing adhesives and / or adhesives with very high early strength are typically used (which also create a rigid and strong bond between parts). The adhesives used for this are mainly hot melt adhesives, two-component acrylic adhesives, or pressure-sensitive adhesives (PSA). They have high enough early strength to immediately hold the pre-fixed parts without further fixing until the actual adhesive has fully cured in the bonded joint.

[0005] However, the most significant limitation of this technology lies in the presence of two adhesives with distinctly different mechanical properties in the final bonded joint: a pre-fixing adhesive and the actual adhesive connecting the components. In most cases, the latter is an elastomer adhesive, which, for example, can compensate for vibrations or thermal movement on the product, which is important for vehicles or appliances. Conversely, the pre-fixing adhesive, depending on the process, is typically a more rigid, higher modulus adhesive, as usually only such adhesives possess sufficiently high early strength. Therefore, the bond exhibits uneven rigidity. Consequently, when the bonded product is subjected to mechanical stress, this results in uneven loading on the bonded surface, where the higher modulus portions may bear stronger loads, potentially leading to mechanical damage or undesirable effects such as vibration or deformation.

[0006] Another drawback of using two different adhesives is that the production line becomes more complex and expensive, and different adhesives require different application equipment.

[0007] Another approach is to use thermosetting or heat-accelerated adhesives for pre-fixation. This allows the pre-fixing adhesive to develop the required strength quickly enough when sufficiently heated before, during, or after application, ensuring pre-fixation. However, a drawback of this method is the need for additional heat treatment, which prolongs production and increases costs. Furthermore, this method is not suitable in all situations. In particular, it is generally not suitable for joining thermoplastic materials because heat-induced deformation can occur on the parts.

[0008] Therefore, there is a need for a pre-fixing and bonding method that involves effective and simple pre-fixation using adhesives, but ultimately achieves a bond with uniform mechanical properties. It may also be advantageous to use a method that can be applied even to heat-sensitive adhesive substrates and can be carried out using the simplest yet most versatile means possible. Invention Overview

[0010] Therefore, the object of the present invention is to provide a pre-fixing and bonding method, which includes effective and simple pre-fixing by means of an adhesive, but ultimately achieves a uniform bond in terms of mechanical properties (especially rigidity), the method being applicable even to heat-sensitive adhesive substrates, and being carried out by means that are as simple as possible in terms of technology but universal.

[0011] According to the present invention, the objective is achieved by the method according to claim 1.

[0012] Surprisingly, it has been found that a multi-step method comprising pre-setting and actual bonding can be performed using a single moisture-curing adhesive and a single accelerator composition, both of which can be achieved by using the single adhesive and single accelerator composition in different mixing ratios. The method of claim 1 results in a mechanically uniform bond after the adhesive has fully cured, and while simplifying application, it does not suffer from the disadvantages of prior art methods that use different adhesives for pre-setting and actual bonding.

[0013] Other aspects of the invention are the subject of the other independent claims. Particularly preferred embodiments of the invention are the subject of the dependent claims. Invention Details

[0015] This invention relates to a method for pre-fixing and bonding two components T1 and T2, comprising the following steps:

[0016] a) Provides a one-component moisture-curing adhesive K and an accelerator composition B, wherein the accelerator composition B contains between 10 and 80% by weight of water, based on the accelerator composition B;

[0017] b) The promoted adhesive KB1 is prepared by mixing the adhesive K and the aqueous accelerator composition B into a promoted adhesive KB1 by means of a static mixer or a dynamic mixer, wherein the promoted adhesive KB1 contains between 5 and 20 vol% of the accelerator composition B based on the whole promoted adhesive KB1, and then the promoted adhesive KB1 is applied to the first part T1.

[0018] c) The optionally promoted adhesive KB2 is prepared by optionally mixing the adhesive K and the aqueous accelerator composition B into an optionally promoted adhesive KB2 by means of a static mixer or a dynamic mixer, wherein the optionally promoted adhesive KB2 contains less than 5% by volume of the accelerator composition B based on the whole promoted adhesive KB2, and then the optionally promoted adhesive KB2 is applied to the first part T1.

[0019] Steps b) and c) are performed in any order, and the amount of promoted adhesive KB1 applied to the first component T1 is less than the amount of optionally promoted adhesive KB2 applied to the first component T1.

[0020] d) Joining the second component T2 at the adhesive position to form a connecting joint T12, which connects the two components T1 and T2 by a promoted adhesive KB1 and optionally a promoted adhesive KB2.

[0021] Substances whose names begin with "poly" or "poly-" (e.g., polyols or polyisocyanates) are, in this document, substances that formally contain two or more functional groups per molecule that appear in their name.

[0022] The term "polymer" herein includes, on the one hand, a collection of chemically homogeneous macromolecules obtained through polymerization reactions (polymerization, addition polymerization, condensation polymerization), but which differ in degree of polymerization, molecular weight, and chain length. On the other hand, the term also includes derivatives of said collection of macromolecules derived from polymerization reactions, i.e., compounds obtained through reactions (e.g., addition or substitution) of functional groups on a given macromolecule and which may be chemically homogeneous or heterogeneous. The term also includes so-called prepolymers, i.e., reactive oligomeric preadditions whose functional groups participate in the formation of macromolecules.

[0023] The term "polyurethane polymer" encompasses all polymers produced by the so-called diisocyanate-addition polymerization method. It also includes those polymers that contain little or no urethane groups. Examples of polyurethane polymers include polyether-polyurethane, polyester-polyurethane, polyether-polyurea, polyurea, polyester-polyurea, polyisocyanurate, and polycarbodiimide.

[0024] The term "silane-functional polymer" refers to polymers containing silane groups, particularly organic polymers containing silane groups, which are generally and especially also described herein as "silane-functional polymers," "silane-modified polymers" (SMP), or "silane-terminated polymers" (STP). Their crosslinking occurs through the condensation of silanol groups, simultaneously forming siloxane bonds, and is typically catalyzed by organotin compounds (e.g., particularly dialkyltin (IV) carboxylate).

[0025] The term "silyl-containing polyether" also includes silyl-containing organic polymers, which may contain urethane, urea, or thiourethane groups in addition to the polyether units. These silyl-containing polyethers may also be referred to as "silyl-containing polyurethanes".

[0026] In this document, the term "silane" or "organosilane" refers to a compound having, on the one hand, at least one, usually two or three, alkoxy or acyloxy groups directly bonded to a silicon atom via Si-O bonds, and on the other hand, at least one organic group directly bonded to a silicon atom via Si-C bonds. Such silanes are also referred to by those skilled in the art as organoalkoxysilanes or organoacyloxysilanes.

[0027] Accordingly, the term "silane group" refers to a silicon-containing group attached to an organic group of a silane via a Si-C- bond. Silanes or their silane groups have the property of hydrolysis upon contact with water. This process forms organosilanes, i.e., organosilicon compounds containing one or more silanol groups (Si-OH- groups), which, through a subsequent condensation reaction, form organosilicon oxanes, i.e., organosilicon compounds containing one or more siloxane groups (Si-O-Si- groups).

[0028] The term "silane-functional" refers to a compound having a silane group. Therefore, a "silane-functional polymer" is a polymer having at least one silane group.

[0029] "Hydroxysilane", "isocyanate silane", "aminosilane" or "mercaptosilane" refers to an organoalkoxysilane that has one or more hydroxyl, isocyanate, amino or mercapto groups in addition to a silane group on its organic group.

[0030] "Primary aminosilane" refers to an aminosilane having a primary amino group (i.e., an NH2- group) attached to one organic group. "Secondary aminosilane" refers to an aminosilane having a secondary amino group (i.e., an NH- group) attached to two organic groups.

[0031] "Molecular weight" is understood in this document as the molar mass (in grams per mole) of a molecule or a portion of a molecule (also referred to as a "group"). "Average molecular weight" represents the number-average M1 of a mixture of molecules or groups in oligomeric or polymeric forms. n It is usually determined by gel permeation chromatography (GPC) relative to polystyrene standards.

[0032] "Storage stable" or "storable" means that a substance or composition can be stored at room temperature in a suitable container for an extended period of time, typically at least 3 to 6 months and longer, without its application or performance properties (particularly viscosity and crosslinking rate) changing to the extent relevant to its use due to storage.

[0033] "Room temperature" refers to a temperature of approximately 23°C.

[0034] Unless otherwise stated, all industry standards or specifications mentioned herein refer to the versions that were in effect prior to the date of this application.

[0035] The terms “mass” and “weight” are used synonymously herein. Therefore, “weight percentage” (wt%) means the percentage mass content, which, unless otherwise stated, is the mass (weight) of all compositions or depends on the relationship of all molecules.

[0036] The term "open time" refers to the time after the adhesive has been applied and begun to cure, during which two parts to be bonded can still be joined without problems.

[0037] The method according to the invention includes providing a one-component moisture-curing adhesive K. The one-component moisture-curing adhesive K comprises at least one polymer that can be crosslinked by moisture. "One-component" means that the adhesive itself can be cured by moisture (e.g., from air) and optionally by the introduction of heat, without the addition of other components.

[0038] In one embodiment of the invention, the crosslinkable polymer is a polyurethane polymer containing isocyanate groups, which is obtained in particular by reacting at least one polyol with at least one polyisocyanate.

[0039] Polyether polyols, polyester polyols, polycarbonate polyols, polyacrylate polyols, and hydrocarbon polyols are particularly suitable as polyols, with polyether polyols being preferred. Preferred polyether polyols are polyoxypropylene polyols and polyoxypropylene polyoxyethylene polyols, especially diols and triols. Diisocyanates are particularly suitable as polyisocyanates. Preferred diisocyanates are 1,6-hexamethylene diisocyanate (HDI), 1-isocyano-3,3,5-trimethyl-5-isocyanomethyl-cyclohexane (isophorone diisocyanate or IPDI), and perhydro-2,4'- and -4,4'-diphenylmethane diisocyanate (HMDI or H... 12 MDI), any mixture of 2,4- and 2,6-toluene diisocyanates and these isomers (TDI), and any mixture of 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanates and these isomers (MDI).

[0040] The polyurethane polymer is prepared by a known method. Its molecular weight is from 500 to 50,000 g / mol, preferably between 1,000 and 30,000 g / mol. The polyurethane polymer also preferably has an average NCO- functionality of 1.8 to 3.

[0041] In another embodiment of the invention, the crosslinkable polymer is a silane-functionalized polymer, particularly a silane-terminated polyether, a silane-terminated poly(meth)acrylate, or a silane-terminated polyurethane. Such polymers are particularly obtained by reacting a polyol with an isocyanate-based silane, by reacting an isocyanate-containing prepolymer with an aminosilane, a hydroxysilane, or a mercaptosilane, by reacting a polyamine with a (meth)acryloylsilane, or by reacting a (meth)acryloyl-terminated polymer with an aminosilane or a mercaptosilane.

[0042] Preferred silane-functionalized polymers are reaction products of polymers optionally end-capped with isocyanate groups and aminosilanes (especially secondary aminosilanes). The secondary aminosilanes preferred for this reaction are alkylaminosilanes, such as 3-(n-butylamino)propyl-alkoxysilane or bis(alkoxysilylpropyl)amine, particularly primary aminosilanes, and Michael adducts with Michael acceptors (e.g., acrylonitrile, (meth)acrylates, maleates, and maleamides). Preferred Michael adducts are reaction products of primary aminosilanes (especially 3-aminopropyl-alkoxysilanes) with acrylates (e.g., n-butyl acrylate or isobornyl acrylate, particularly dialkyl maleate). Most preferred are Michael adducts of 3-aminopropyl-dialkoxyalkylsilanes or 3-aminopropyl-trialkoxysilanes with dialkyl maleates (especially diethyl maleate).

[0043] The silane group, particularly the dialkoxyalkylsilane group, is preferred, especially the trialkoxysilane group. The preferred alkoxy group on the silane group is an ethoxy group, particularly a methoxy group.

[0044] For example, suitable silane-functionalized polymers are commercially available from Hanse Chemie AG (Germany) under the trademark Polymer ST (e.g., Polymer ST50), and under the trademark... Purchased commercially from Bayer Material Science AG (Germany).

[0045] Other suitable silane-functionalized polymers are marketed under their respective trademarks. 1010LM, 1015LM, and 1050MM were commercially available from Momentive Performance Materials Inc. (USA), and also under the brand name... STP-E15, STP-10 and STP-E35 were commercially available from Wacker Chemie AG (Germany).

[0046] Similarly suitable silane-functionalized polymers, such as those traded under the names MS Polymer S203H, S303H, S227, S810, MA903 and S943, Silyl SAX220, SAX350, SAX400 and SAX725, Silyl SAT350 and SAT400, and XMAP SA100S and SA310S, are commercially available from Kaneka Corp. (Japan), and are also available under the trade name... S2410, S2420, S3430, S3630, W2450 and MSX931 were commercially available from Asahi Glass Co, Ltd. (Japan).

[0047] The described adhesive K (especially when it is based on a polyurethane polymer or a silane-functionalized polymer) may additionally contain the following known auxiliaries and additives:

[0048] Plasticizers, such as esters of organic carboxylic acids or their anhydrides, phthalates such as dioctyl phthalate or diisodecyl phthalate, adipates such as dioctyl adipate, sebacic acid esters, organophosphates and sulfonates, polybutene and other compounds that do not react with isocyanates; reactive diluents and crosslinking agents, such as polyols, polyamines, polyaldehyde imides, polyketide imides or aliphatic isocyanates, such as 1,6-hexamethylene diisocyanate, 2,2,4- and 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, 1,12-dodecyl diisocyanate, cyclohexane-1,3- and 1,4-diisocyanate and any mixtures of these isomers, 1-isocyanate-3 3,5-Trimethyl-5-isocyanomethyl-cyclohexane (=isophorone diisocyanate or IPDI), perhydro-2,4'- and -4,4'-diphenylmethane diisocyanates, 1,3- and 1,4-tetramethylxylene diisocyanate, isocyanurates of these isocyanates, oligomers and polymers of these isocyanates and their adducts with polyols; inorganic and organic fillers, such as milled or precipitated calcium carbonate, optionally coated with stearate, especially finely coated calcium carbonate, carbon black, kaolin, alumina, silica and PVC powder or hollow spheres; fibers, such as polyethylene fibers; pigments; catalysts, such as organotin compounds, such as dibutyl dilaurate. Tin, dibutyltin dichloride, dibutyltin diacetylacetonate, bismuth organic compounds or bismuth complexes, or amine-containing compounds, such as 2,2'-dimorpholinodiethyl ether, or other common catalysts used in polyurethane chemistry or silane chemistry for reactions involving isocyanate groups or alkoxysilyl groups; other catalysts for the hydrolysis of polyaldehyde imides (if present), such as organic carboxylic acids, such as benzoic acid or salicylic acid, organic carboxylic anhydrides, such as phthalic anhydride or hexahydrophthalic anhydride, silyl esters of organic carboxylic acids, organic sulfonic acids such as p-toluenesulfonic acid or 4-dodecylbenzenesulfonic acid, or another organic or inorganic acid, or mixtures of the above acids; rheology modifiers, such as thickeners, for example... Urea compounds, polyamide waxes, bentonite or pyrolytic silica; tackifiers, especially silanes, such as epoxy silanes, vinyl silanes, isocyanate silanes and amino silanes that react with aldehydes to form aldehyde iminosilanes, and oligomeric forms of these silanes; desiccants, such as p-toluenesulfonyl isocyanate and other reactive isocyanates, orthoformates, calcium oxide or molecular sieves; stabilizers resistant to heat, light and ultraviolet radiation; flame retardants; surfactants, such as wetting agents, leveling agents, degassing agents or defoamers; fungicides or fungal growth inhibitors; and other substances commonly used in the preparation of moisture-curing compositions, the suitability of which for use as additives in various adhesives is apparent to those skilled in the art.

[0049] Particularly suitable as adhesives K are one-component moisture-curing compositions based on isocyanate-containing polyurethane polymers or silane-functionalized polymers. Such compositions, for example, can be marketed under trade names... or Obtained from Sika Schweiz AG.

[0050] The method according to the invention further includes providing an accelerator composition B, which contains between 10 and 80% by weight of water, based on the accelerator composition B. The accelerator composition B preferably contains between 10 and 60% by weight of water, particularly between 15 and 40% by weight, based on the entire accelerator composition B.

[0051] Accelerator composition B primarily contains at least water. To ensure good incorporation of water into accelerator composition B, it is advantageous that accelerator composition B includes a carrier, which on the one hand increases the viscosity of accelerator composition B, and on the other hand advantageously influences the mixing ratio. Since less water is required to accelerate curing, and such small-volume mixing may lead to problems with uniform mixing, the mixing problem is reduced by using a carrier material to decrease the volume ratio of binder K to accelerator composition B. It is also known that mixing two components with significantly different viscosities is difficult. This difficulty is reduced by using a carrier material. The carrier material is advantageously an organic polymer having ionic groups. Such ionic groups are particularly carboxylic acid groups and / or sulfonic acid groups. Poly(meth)acrylic acid and copolymers of (meth)acrylic acid are advantageous as such organic polymers. The carrier material is particularly advantageously a polyurethane having at least one carboxylic acid group and / or sulfonic acid group. Polyurethanes synthesized using diols containing carboxylic acid groups (particularly dimethylolpropanecarboxylic acid) and polyisocyanates are particularly suitable as carrier materials. By using such a carrier material, water is reversibly bound by the carrier material having ionic groups and forms a gel-like paste.

[0052] The amount of water relative to the wet reactive groups can be substoichiometric to superstoichiometric, and it is particularly suitable that the ratio of reactive groups [H2O] / [NCO] or [H2O] / [silicon-bound alkoxy groups] is 1 to 3.0, especially 1 to 2.6. A substoichiometric ratio, especially 1 to 2, is preferred.

[0053] Other possibilities exist for formulating water-based pastes. Here, water is mixed with fine-particle fillers (e.g., pyrolytic silica, such as that obtained from Degussa). It can be mixed with chalk or molecular sieves. Here, water can reversibly bind to the surface or pores of the packing material.

[0054] However, organic polymers with ionic groups are preferred as carriers.

[0055] Aqueous pastes containing ionic groups, which can be used as accelerator compositions B according to the present invention, are known in principle, and for example are... -254 or -Plus, which is a one-component hot melt polyurethane adhesive and is mixed in -254 Booster System or -PlusBooster System.

[0056] It may be advantageous that the accelerator composition B contains polyols and / or polyamines in addition to water. For example, this could lead to faster complete curing and a quicker attainment of final strength.

[0057] Water in accelerator composition B may exist in the form of free water or may be bound to the carrier material. However, this binding must be reversible, that is, after the binder K and accelerator composition B are mixed, the water must be able to participate in the reaction with the wet reactive groups (especially isocyanate groups, alkoxy groups and / or aldehyde imine groups) in the binder K.

[0058] Suitable carrier materials for accelerator composition B can be hydrates or hydrated complexes, particularly inorganic compounds that bind water in a coordinated manner or with water of crystallization. Examples of such hydrates are Na₂SO₄·10H₂O, CaSO₄·2H₂O, CaSO₄·H₂O, Na₂B₄O₇·10H₂O, and MgSO₄·7H₂O.

[0059] Other suitable carrier materials are porous materials that enclose water within cavities. Specific silicates and zeolites are particularly suitable. Diatomaceous earth and molecular sieves are especially appropriate. The size of the cavity is selected to best suit water absorption. Therefore, the pore size is... Molecular sieves are particularly suitable.

[0060] Other suitable carrier materials are those that absorb non-stoichiometric amounts of water and have a paste-like consistency or form a gel. These carrier materials can be inorganic or organic. Examples include silica gel, clay (e.g., montmorillonite, bentonite, lithium montmorillonite), or polysaccharides (e.g., cellulose and starch), or polyacrylic acid and polyacrylonitrile, which are also known by the term "superabsorbent" and are used, for example, in hygiene products. Carrier materials with ionic groups are also suitable. Particularly preferred carrier materials are polyurethane polymers or their salts, especially ammonium salts, having carboxyl or sulfonic acid groups as side chains. These carrier materials can absorb and bind water until their absorbency is exhausted.

[0061] Particularly preferred polyurethane polymers, or salts thereof, having carboxyl or sulfonic acid groups as side chains, can be obtained, for example, from polyisocyanates and polyols containing carboxylic or sulfonic acid groups. The acid groups can then be neutralized with a base (especially a tertiary amine), for example, in a fully reactive state. The properties of the support material depend largely on the functional polyol and polyisocyanate used. Special attention should be paid to the hydrophilicity or hydrophobicity of the selected isocyanate and polyol. Short-chain polyols have been found to produce particularly suitable support materials.

[0062] When used with polyurethane adhesives, accelerator composition B preferably further comprises at least one polyaldehyde imide. The polyaldehyde imide can be prepared by a condensation reaction of at least one polyamine having an aliphatic primary amino group and at least one aldehyde, followed by the removal of water. Such a condensation reaction is well known and described, for example, in Houben-Weyl's "Methoden derorganischen Chemie," Vol. XI / 2, page 73 and thereafter. The condensation reaction is an equilibrium reaction, where the equilibrium is predominantly on the polyaldehyde imide side. This means that when a polyamine having an aliphatic primary amino group is mixed with at least one stoichiometric amount of an aldehyde, the corresponding polyaldehyde imide will spontaneously form, regardless of whether the water decomposed in the reaction is removed from the reaction mixture.

[0063] As a polyamine with aliphatic primary amino groups for the preparation of polyaldehydes, polyamines known in polyurethane chemistry, especially those used in two-component polyurethanes, can be considered.

[0064] Preferred polyamines are 1,6-hexamethylenediamine, MPMD, DAMP, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, 4-aminomethyl-1,8-octanediamine, IPDA, 1,3- and 1,4-xylenyldiamine, 1,3- and 1,4-bis-(aminomethyl)cyclohexane, bis-(4-aminocyclohexyl)-methane, bis-(4-amino-3-methylcyclohexyl)-methane, 3(4),8(9)-bis-(aminomethyl)-tricyclo-[5.2.1.0] 2,6 Decane, 1,2,1,3- and 1,4-diaminocyclohexane, 1,4-diamino-2,2,6-trimethylcyclohexane, and polyoxyalkylene polyamines theoretically having two or three amino groups, especially EDR-148 D-230 D-400 and T-403, and especially mixtures of two or more of the above-mentioned polyamines.

[0065] Advantageously, the accelerator composition B contains at least an amount of water sufficient to completely convert any polyaldehyde imine present into a polyamine. This means that the accelerator composition B preferably contains at least the same number of moles of water as the present aldehyde imine groups, or in other words, the accelerator composition B preferably has at least one molecule of water relative to each aldehyde imine group.

[0066] The accelerator composition B preferably further comprises at least one external emulsifier, particularly a nonionic emulsifier, such as a fatty alcohol ethoxylate.

[0067] The accelerator composition B preferably has an emulsifier content of ≤10% by weight, particularly ≤5% by weight.

[0068] In addition, the accelerator composition B may optionally contain rheology modifiers or fillers, particularly pyrolytic silica and urea.

[0069] Preferably, the accelerator composition B optionally further comprises at least one polymer and / or at least one acid and / or at least one catalyst for curing the wet-curing adhesive. The polymers mentioned particularly include water-bound polymers as described above, polyols for reacting with isocyanate-containing prepolymers (if present in the adhesive), or polyaldehydes as described above.

[0070] In step b) of the method according to the invention, the adhesive K and the accelerator composition B are mixed by means of a static mixer or a dynamic mixer to form an accelerated adhesive KB1, wherein the accelerated adhesive KB1 contains between 5 and 20 vol% of the accelerator composition B based on the total accelerated adhesive KB1.

[0071] In step c) of the method according to the invention, the adhesive K and the accelerator composition B are optionally mixed using a static or dynamic mixer to form an optionally accelerated adhesive KB2, wherein the optionally accelerated adhesive KB2 contains less than 5% by volume of the accelerator composition B based on the entire accelerated adhesive KB2. The optionally accelerated adhesive KB2 is optionally accelerated only; it may also consist only of adhesive K. Whether to add up to 5% by weight of the accelerator composition B depends essentially on the desired bonding process and the associated production cycle time. However, if the method allows, it is preferable to mix the accelerator composition B, as this allows for a reduction in curing time.

[0072] The mixing of adhesive K and accelerator composition B is advantageously carried out continuously during application throughout the method. In one possible embodiment, the mixing of adhesive K and accelerator composition B is performed by a metering unit comprising two intermeshing metering rotors. Details of the preferred metering unit are described in patent specification EP 0 749 530. For smaller applications, the metering unit is preferably disposed on a commercially available cartridge containing adhesive K, while the accelerator composition B is located in a container integrated within the metering unit. Metering and mixing are performed in the metering unit during application, which is passively operated, for example by means of a commercially available cartridge press, by pressurizing the cartridge. For better mixing, a static mixer can also be installed at the outlet of the metering unit.

[0073] Another possibility for mixing adhesive K and accelerator composition B is a commercially available so-called dual-cassette or coaxial cassette, each with a static mixer mounted on an outlet. When using a dual-cassette, adhesive K and accelerator composition B are located in separate cassettes fixed side-by-side, leading to a common outlet. Application is made by means of a suitable extrusion device that extrudes the two cassettes in parallel. When using a coaxial cassette, one of the two components is located in the core of the cassette. The other component surrounds it, and these components are separated by a coaxial wall. During application, both components are similarly extruded simultaneously by a suitable extrusion device and converge into a common outlet.

[0074] In one embodiment, it is a dual-component container (as known from two-component adhesives), wherein the arrangement of the chambers can be designed in different ways. For example, the chambers can be cylindrical chambers arranged side-by-side or concentrically. The walls of the chambers can be rigid or flexible. Exemplary arrangements and designs of the chambers can be found in WO 01 / 44074 or US 6,433,091 B1.

[0075] Conversely, for industrial applications, it is advantageous to deliver the adhesive K and accelerator composition B from a drum or container. In this case, it is advantageous to mix the adhesive K and accelerator composition B using a metering unit, which differs essentially from the metering unit described above in that it has a hose fitting for the accelerator composition B.

[0076] In one embodiment, the accelerator composition B is present in a package through which it is metered and mixed into the stream of adhesive K. Examples of such packaging or metering are found, for example, in WO 95 / 24556. This packaging / metering device is advantageously bolted to the outlet of the cartridge or the opening of the adhesive pump.

[0077] In another embodiment, the accelerator composition B is incorporated into the adhesive K and mixed using a dynamic mixer.

[0078] In another embodiment, the accelerator composition B is sprayed into the adhesive K through multiple distributed nozzles and then mixed.

[0079] The accelerator composition B can be mixed into the binder K either uniformly or in layers. Layers can be obtained, especially when a small number (typically between 3 and 10) of mixing elements are arranged in a static mixer.

[0080] If uniform mixing is desired, a dynamic mixer is preferred, or multiple (typically more than 12, especially more than 15) mixing elements can be used in a static mixer. Substantially uniform mixing is preferred. If the accelerator composition B and the binder K are mixed substantially in layers, for example by a static mixer with a small number of mixing elements, a uniform, fully cured product will typically still be produced after complete curing, where the original layers are no longer visible.

[0081] During and after the mixing of accelerator composition B and adhesive K, the moisture-curing adhesive reacts with water and / or with hydrolytic agents (such as the hydrolyzed form of polyaldehyde imine, which may be included) through the crosslinkable polymer contained therein. Adhesive K eventually cures after application through all these reactions. It may subsequently react with water absorbed from the air (air moisture), which could further allow adhesive K to fully cure completely.

[0082] In a preferred embodiment of the method, the accelerator adhesive KB1 and / or optionally the accelerator adhesive KB2 are applied using a handheld application device (particularly a glue gun). As mentioned above, the mixing of the accelerator composition B and the adhesive K can be carried out directly in the application device.

[0083] In another preferred embodiment of the method, the promoted adhesive KB1 and / or optionally the promoted adhesive KB2 are applied by means of an automatic application device having a movable application nozzle. As described above, the mixing of the accelerator composition B and the adhesive K can be carried out directly in the application device.

[0084] The application device in the two preferred methods mentioned above preferably includes two separate chambers, wherein the adhesive K and the accelerator composition B are each located in one of the two chambers.

[0085] In addition, the application device preferably includes a mixing chamber into which two chambers converge, and the mixing chamber has a static mixer or a dynamic mixer.

[0086] The promoted adhesive KB1 and optionally the promoted adhesive KB2 can be applied in the same or different manner. However, it is advantageous to apply the promoted adhesive KB1 in the smallest possible amount, such that the amount of adhesive present is just sufficient to ensure pre-fixation of the two parts T1 and T2 to be bonded without other means of fixation. This is preferably done at statically relevant critical locations where particularly large forces will be applied during the movement of the bonded parts T1 and T2. The minimum amount of promoted adhesive KB1 required in a particular bonding method depends essentially on the weight and geometry of the parts to be bonded and the mechanical properties of the adhesive KB1, and can be readily determined by those skilled in the art through routine testing.

[0087] A preferred embodiment of the method according to the invention comprises the following steps in a given order:

[0088] 1) Provides a one-component moisture-curing adhesive K and an accelerator composition B, wherein the accelerator composition B contains between 10 and 80% by weight of water, based on the accelerator composition B;

[0089] 2) The optionally promoted adhesive KB2 is prepared by optionally mixing the adhesive K and the aqueous accelerator composition B into an optionally promoted adhesive KB2 using a static mixer or a dynamic mixer, wherein the optionally promoted adhesive KB2 contains less than 5% by volume of the accelerator composition B based on the whole promoted adhesive KB2.

[0090] 3) Apply the optional accelerated adhesive KB2 to the first component T1;

[0091] 4) The promoted adhesive KB1 is prepared by mixing the adhesive K and the aqueous accelerator composition B with the aid of a static mixer or a dynamic mixer to form the promoted adhesive KB1, wherein the promoted adhesive KB1 contains between 5 and 20 vol% of the accelerator composition B based on the whole promoted adhesive KB1.

[0092] 5) Apply the promoted adhesive KB1 to the component T1, wherein the amount of promoted adhesive KB1 applied is less than the amount of optionally promoted adhesive KB2 applied;

[0093] 6) Join the second component T2 at the adhesive position to form a connecting joint T12, which connects the two components T1 and T2 by a promoted adhesive KB1 and optionally a promoted adhesive KB2.

[0094] In a preferred embodiment, an optional promoted adhesive KB2 is first applied to a first component T1, and then a promoted adhesive KB1 is discontinuously applied to the first component T1 during the open time of the optional promoted adhesive KB2. Preferably, the promoted adhesive KB1 is applied in a dotted manner, with the promoted adhesive KB1 applied near or between the optional promoted adhesive KB2 on the first component. Such application creates a joint T12 having a large area of ​​the optional promoted adhesive KB2 applied and the promoted adhesive KB1 applied in a dotted manner between or near it.

[0095] In another preferred embodiment, the promoted adhesive KB1 is applied in the form of a thin strip of adhesive, and the promoted adhesive KB1 is applied near or between an optional promoted adhesive KB2, wherein less than half of the adhesive gap between components T1 and T2 is filled by the promoted adhesive KB1.

[0096] Alternatively, depending on the type and geometry of the parts T1 and T2 to be bonded, a promoted adhesive KB1 can be applied first to join the parts, and then an optional promoted adhesive KB2 can be injected into the cavity of the formed local joint. Therefore, pre-fixation can also be achieved with KB1 before applying the optional promoted adhesive KB2. However, this method requires complex injection steps, which is not feasible in every case.

[0097] In all cases according to the method of the invention, the adhesive in the joint T12 must consist of less than half of the promoted adhesive KB1 and more than half of the optionally promoted adhesive KB2. Based on the area of ​​the applied adhesives KB1 and KB2, all adhesives in the joint T12 preferably consist of at most 25% of the promoted adhesive KB1 and at least 75% of the optionally promoted adhesive KB2. Based on the area of ​​the applied adhesives KB1 and KB2, all adhesives in the joint T12 preferably consist of at most 10% of the promoted adhesive KB1 and at least 90% of the optionally promoted adhesive KB2.

[0098] In some embodiments of the method, it is advantageous to apply an activator, tackifier, or primer to the surfaces of parts T1 and / or T2 to be bonded before applying adhesive KB1 and / or adhesive KB2.

[0099] In some embodiments of the method, it is also advantageous to heat the promoted adhesive KB1 and / or adhesive KB2 before, during, or after application. This promotes the establishment of adhesive strength and shortens the open time.

[0100] When the optionally accelerated adhesive KB2 is mixed and applied, the accelerator composition B is preferably used in proportion to the adhesive K such that at least 50%, preferably 100%, of all reactive groups of the crosslinkable polymer in all optionally accelerated adhesive KB2 can react with the water present in the accelerator composition B. However, it is also possible to apply the optionally accelerated adhesive KB2 completely unmixed with the accelerator composition B. In this case, curing can only be achieved by water from the environment (e.g., air moisture).

[0101] In a preferred embodiment of the method, the optionally promoted adhesive KB2 contains between 0.5 and 5% by volume of the accelerator composition B.

[0102] When the accelerated adhesive KB1 is mixed and applied, the accelerator composition B is preferably used in proportion to the adhesive KB1 such that 100% of all reactive groups of the crosslinkable polymer in all accelerated adhesive KB1 can react with the water present in the accelerator composition B. It is possible to use a one-molar excess of water relative to the wet reactive groups of the adhesive. The excess water further promotes the curing of the accelerated adhesive KB1.

[0103] In a preferred embodiment of the method, the promoted adhesive KB1 comprises between 7.5 and 12.5 vol% of accelerator composition B.

[0104] After applying promoted adhesive KB1 and optionally promoted adhesive KB2 and joining components T1 and T2, a connecting joint T12 is formed, which connects the two components T1 and T2 through promoted adhesive KB1 and optionally promoted adhesive KB2.

[0105] Due to the different water content in the accelerated adhesive KB1 and the optional accelerated adhesive KB2, the two mixtures KB1 and KB2 achieve different open times, with the accelerated adhesive KB1 exhibiting a shorter open time and faster early strength development. Surprisingly, this has no significant effect on the mechanical properties (particularly stiffness and modulus) of adhesive K after complete curing. Both the accelerated adhesive KB1 and the optional accelerated adhesive KB2 exhibit very similar mechanical properties (particularly in modulus, tear strength, and elongation at break) and identical adhesive properties after complete curing.

[0106] If water is incorporated in the form of accelerator composition B in both cases, then contact between the accelerated adhesive KB1 and optionally the accelerated adhesive KB2 and water in the form of atmospheric moisture is not absolutely necessary for curing, but it is still advantageous. In particular, post-curing of the composition can be carried out using atmospheric moisture.

[0107] The curing of the promoted adhesive KB1 and optionally the promoted adhesive KB2 is carried out specifically at room temperature. In some cases, it may be advantageous to post-cure or fully cure the partially cured composition by means of an elevated temperature (e.g., in the range of 40 to 100°C). It is also advantageous to heat the promoted adhesive KB1 and optionally the promoted adhesive KB2 before, during, or after application. The advantage is that this facilitates pumpability and application by reducing viscosity, and also promotes curing.

[0108] Specifically, the curing of the accelerated adhesive KB1 is carried out in such a way that sufficient open time is ensured on the one hand, and curing is carried out to a certain extent or early strength is rapidly established within a few minutes, so that further pre-fixing can be achieved, or the bond achieved with the accelerated adhesive KB1 is self-supporting and can be transported.

[0109] By using the described method with accelerated adhesive KB1 and optionally accelerated adhesive KB2, it is possible to formulate modular (modular) pre-fixing and bonding systems that require only a single adhesive K and a single accelerator composition B. Depending on the application requirements, different mixing ratios of adhesive K and accelerator composition B can be set to prepare accelerated adhesive KB1 and optionally accelerated adhesive KB2. Using such a system, process parameters such as processing time (open time), early strength, and curing speed can be easily adapted to various desired manufacturing processes without changing adhesive K and accelerator composition B. For example, this is highly advantageous for small-batch industrial production because, in this way, production lines can be essentially modified for another product, and it is not necessary to store all types of adhesives.

[0110] The method according to the invention is applicable to the pre-fixation and bonding of various substrates, for example, for bonding components in the manufacture of automobiles, rail vehicles, ships or other industrial goods, and also for sealing joints in buildings.

[0111] The method according to the invention is preferably used in adhesive and sealing applications in the construction and manufacturing industries, as well as in vehicle manufacturing, particularly for joint sealing, floor bonding, mounting component bonding, weld sealing, cavity sealing, assembly, body bonding, window bonding, roof sealing, etc. This is particularly advantageous if, for example, it is desirable for the moisture-curing composition to cure faster than curing by air moisture alone, for reasons such as: short production cycle times during bonding or as short a waiting time as possible in maintenance situations; working under adverse climatic conditions (e.g., winter or desert climates); low water vapor permeability of the composition and / or substrate; thick adhesive joints; or adhesive shapes that discourage the entry of air moisture.

[0112] The method according to the invention is particularly suitable for bonding substrates selected from: concrete, mortar, brick, tile, ceramic, gypsum, natural stone such as granite or marble, glass, glass ceramics, metal or metal alloy (e.g., aluminum, steel, non-ferrous metals, galvanized metal), wood, plastics (e.g., PVC, polycarbonate, poly(meth)acrylate, polyester, epoxy resin), composite materials, dyes or paints.

[0113] Furthermore, the present invention relates to products comprising at least two components bonded together, obtained by the method described above. These products (articles) are particularly buildings, industrial products, or means of transport, or parts thereof.

[0114] Examples of such items include houses, glass curtain walls, windows, bathrooms, shower rooms, kitchens, roofs, bridges, tunnels, streets, cars, trucks, rail vehicles, buses, ships, mirrors, car windows, bathtubs, white goods, household appliances, dishwashers, washing machines, ovens, spotlights, fog lights, or solar panels, such as photovoltaic modules or solar thermal modules.

[0115] The adhesive substrate comprising the first component T1 and the second component T2 can be composed of a variety of materials. Plastics are particularly suitable, as are organic materials such as leather, fabrics, paper, wood, wood-based materials bonded with resin, resin-fabric-composite materials, glass, porcelain, ceramics, and metals, especially painted metals.

[0116] Suitable plastics include, in particular, polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene copolymer (ABS), SMC (sheet molding compound), polycarbonate (PC), polyamide (PA), polyester (PE), polyoxymethylene (POM), polyolefins, especially polyethylene (PE) or polypropylene (PP), preferably PP or PE surface treated with plasma, corona or flame.

[0117] Preferred materials suitable as substrates (including the first component T1 and the second component T2) are metals and polyolefins, especially painted metals and polypropylene or polyethylene that have been surface-treated by plasma, corona or flame.

[0118] Promoted adhesive KB1 and optionally promoted adhesive KB2 are particularly suitable as assembly adhesives. In this document, "assembly adhesive" refers to an adhesive that rapidly builds strength, and therefore is suitable for bonding parts that must be moved shortly after application. Therefore, in particular, promoted adhesive KB1 must be able to transfer force between the joined objects in a short time. Assembly adhesives are commonly used in industrial production, especially in assembly line processes. Particularly preferred are the adhesives used in the construction of transportation vehicles (particularly vehicles, especially automobiles).

[0119] For example, the prefabricated modules can be pre-fixed and bonded to the vehicle body using the method according to the invention. Example

[0120] The following describes embodiments that explain the invention in more detail. The invention is, of course, not limited to the described embodiments.

[0121] Measurement Method Description

[0122] According to DIN EN ISO 527 (tensile speed: 200 mm / min, sample shape 5A), tensile strength, elongation at break, and modulus of elasticity (“E-modulus”) in the range of 0.5-5% elongation were determined on dumbbell-shaped samples with a length of 75 mm, a beam length of 30 mm, and a beam width of 4 mm. The dumbbell-shaped samples were obtained by stamping an approximately 2 mm thick film of adhesives KB1 and KB2 cured under standard climate conditions.

[0123] The tensile shear strength was tested using the following method: Each measurement used two KTL-painted steel plates (DC04 steel, coated with BASF) that were degreased with isohexane, each 0.8 mm thick, 25 mm wide, and 100 mm long. 800; from Germany (Originally obtained from Rocholl GmbH). After a 10-minute ventilation period, the sheets are arranged vertically relative to each other at a distance of 2 mm using a suitable PTFE mold, such that they overlap by 12.5 mm at the head ends. The overlapping areas between the sheets are filled with adhesive, which is applied to the degreased side of the sheets. The sheets bonded together in this manner are stored at 23°C and 50% relative humidity for 24 hours. After that, they are stretched until fractured using a tensile testing machine (Zwick) according to DIN EN 1465 at a constant beam speed of 10 mm / min, and the result is measured in MPa (N / mm). 2 The fracture force (“Standard”) was measured. A second series of measurements (“Aging”) involved storing the bonded sheets in water for 7 days (deionized water <5 μS / cm), then at 80°C for 24 hours, then at 70°C and 95% relative humidity for 7 days, and finally at 100°C for 7 days. All samples were conditioned at 23°C and 50% relative humidity for 2 hours prior to measurement. The given values ​​are the average of the two measurements. Fracture patterns are given in parentheses (“CF” indicates complete cohesive failure).

[0124] The opening time was determined as follows: For each measurement in a measurement series, under standard climatic conditions (23°C, 50% relative humidity), triangular strips of adhesive, each 10 mm wide and 10 mm high, were applied along the long side of a cleaned and degreased glass sheet (40 x 100 x 6 mm). After waiting periods of 1, 3, 5, and 10 minutes (depending on the measurement), the sheet was placed in the sample holder of a Zwick Roell Zwicki 1020 testing machine. A second glass sheet was placed horizontally parallel above the first sheet with adhesive, with a sufficiently large gap to avoid contact with the triangular strips. The testing machine then applied vertical pressure to the triangular strips by moving the second glass sheet toward the first. The speed at which the second sheet moved toward the first sheet was always 200 mm / min. The force required to compress each triangular strip to a thickness of 5 mm was recorded. When the measured force reaches or exceeds 10 N / cm (N / cm adhesive strip length), it is considered to be the end of the adhesive open time, which is measured by measuring the time period (1 to 10 minutes) during which each sample has cured.

[0125] The time required to reach the minimum required early strength (i.e., the curing time required for the bond to withstand a load without further fixation) is determined by the following method: A 0.8mm thick, 500mm long (horizontal) and 200mm wide (vertical) KTL-painted steel sheet (material: DC04 steel, coated with BASF) is suspended vertically. 800; from Germany A 1cm thick rectangular PTFE sheet was placed along the entire length of a steel sheet (obtained from Rocholl GmbH). An adhesive strip was applied along the entire length of the right angle between the steel sheet and the PTFE sheet. Immediately afterward, during the adhesive's open time, smaller KTL-painted steel sheet sheets of the same material, 0.8mm thick, 60mm long, and 25mm wide, were pressed vertically downwards parallel to each other along their length to the adhesive surface at 2cm intervals, creating an adhesive surface of 25 x 20mm and 3mm thick for each sheet (achieved via a placeholder), with the upper edge of each sheet contacting the PTFE sheet. The steel sheet sheets had holes in the non-adhesive areas. After a certain time depending on the test, a weight of 500g applied through the holes was applied to each individual sheet. A separate time was chosen for each sheet. If the sheet was observed to move downwards within 10 minutes after the weight was applied, early strength had not yet been reached after that time in the test. The time to reach the minimum required early strength is the waiting time of the first test in which no movement in the sheet is observed within 10 minutes after the application of weight.

[0126] To determine adhesion, adhesive strips were applied to the appropriate substrate, subjected to different storage conditions, and then tested using a "strip test" at room temperature (23°C) and 50% relative humidity. The strip was cut at the end immediately above the adhesive surface. The cut end of the strip was held in place with round-nose pliers and torn off the substrate. This was done by carefully winding the strip around the pliers and making a cut perpendicular to the tearing direction, extending to the blank substrate. The strip stretching speed was chosen such that a cut was made approximately every 3 seconds. The test length had to be at least 8 cm. The adhesive residue left on the substrate after the strip was removed (cohesive breakage) was evaluated. Adhesion was assessed by evaluating the cohesive ratio of the adhesive surface.

[0127] 1 = >95% cohesive fracture; 2 = 75-95% cohesive fracture; 3 = 25-75% cohesive fracture; 4 = <25% cohesive fracture; 5 = 0% cohesive fracture (pure adhesive fracture). Test results with a cohesive fracture value less than 75% are generally considered insufficient.

[0128] As the first substrate (“Substrate 1”), a KTL-coated steel sheet (DC04 steel, coated with BASF) with a thickness of 0.8 mm, a width of 25 mm, and a length of 100 mm is used. 800; from Germany (Originally obtained from Rocholl GmbH), the steel sheet was pre-cleaned with isopropyl alcohol and ventilated for 10 minutes.

[0129] As a second substrate (“substrate 2”), the same cleaned sheet is used, but in this case, the sheet is also treated with SikaPrimer-207 and ventilated for 10 minutes before the adhesive is applied.

[0130] The adhesive storage conditions are as follows: 7 days at 23°C and 50% relative humidity (“7d RT”), 7 days in a water bath at 20°C (“7d water”), 1 day at 80°C and 50% relative humidity (“1d 80°C”), 7 days of adhesive storage at 70°C and 100% relative humidity (“7d adhesive”), and finally 7 days at 100°C (“7d 100°C”).

[0131] Moisture-curing composition

[0132] Adhesive K: Polyurethane adhesive used -270 (obtained from Sika Schweiz AG) is used as a one-component moisture-curing adhesive K.

[0133] Accelerator Composition B: Use Booster AC-30 (an aqueous paste containing 15-30% by weight of water, obtained from Sika Schweiz AG) was used as accelerator composition B.

[0134] The accelerated adhesive KB1 was obtained as follows: Adhesive K and accelerator composition B were mixed at a volume ratio of 10:1 in a laboratory apparatus (Sulzer MS 13-18G static mixer) equipped with a gear metering feeder. Accelerated adhesive KB1 containing approximately 10% by volume of accelerator composition B was obtained. Adhesive K was heated to a temperature of 60°C during application. The extrusion speed for applying adhesive KB1 was 5 cm. 3 / s. KB1's open time is 1 minute.

[0135] The optional accelerated adhesive KB2 was obtained as follows: Adhesive K and accelerator composition B were mixed at a volume ratio of 50:1 (K:B) in a laboratory apparatus (static mixer Sulzer MS 13-18G) equipped with a gear metering feeder. This yielded the optional accelerated adhesive KB2 containing approximately 2% by volume of accelerator composition B. Adhesive K was heated to 40°C during application. The extrusion speed for applying adhesive KB2 was 5 cm. 3 / s. KB2's open time is 5 minutes.

[0136] Measurement results

[0137] The results of the mechanical tests are listed in Table 1.

[0138] For details of the results, as well as the relevant abbreviations and definitions, please refer to the description above.

[0139] Table 1 shows that for pre-fixing adhesive KB1, sufficient early strength is achieved after 5 minutes, allowing the bond to withstand loads without additional pre-fixing. Adhesive KB2 requires 30 minutes to achieve the same early strength. The lower final tensile shear strength of adhesive KB1 does not significantly contribute to the bond, as final fixation is achieved through adhesive KB2, which constitutes a larger portion of the bond in the method according to the invention. Regarding modulus, pre-fixing adhesive KB1 is found to have a surprisingly lower modulus than the final adhesive KB2. This avoids the effect of all mechanical loads after final bonding acting on a much smaller amount of pre-fixing adhesive (as is common in the prior art). The more rigid, higher modulus portion of the bond must withstand a greater mechanical load. Furthermore, the modulus difference between KB1 and KB2 is surprisingly small for pre-fixed bonds. It is also found that pre-fixing adhesive KB1 achieves strong, resilient pre-fixed bonds. The bond is not adversely affected by the method of the invention, as both adhesives KB1 and KB2 exhibit excellent adhesive behavior at all times.

[0140] adhesives KB1 KB2 Tensile strength [MPa] 6.8 6.2 Elongation at break [%) 589 522 Elastic modulus [MPa] 3.4 3.9 Tensile shear strength (standard) [MPa] 1.8(CF) 3.5(CF) Tensile shear strength (aging) [MPa] 1.3(CF) 3.0(CF) Adhesion 7d RT (Substrate 1 / Substrate 2) 1 / 1 1 / 1 Adhesive 7-day water (substrate 1 / substrate 2) 1 / 1 1 / 1 Adhesion 1 day at 80℃ (substrate 1 / substrate 2) 1 / 1 1 / 1 Adhesive 7D poultice (Substrate 1 / Substrate 2) 1 / 1 1 / 1 Adhesion 7 days at 100℃ (substrate 1 / substrate 2) 1 / 1 1 / 1 Opening hours [min] 1 5 Time to reach minimum required early intensity [min] 5 30

[0141] Table 1: Measurement results.

Claims

1. Method for pre-fixing and bonding a first part T1 and a second part T2, comprising the following steps: a) providing a one-component moisture-curing adhesive K and an accelerator composition B, the accelerator composition B comprising between 10 and 80 wt.% water and no catalyst based on the accelerator composition B, and the adhesive K being a composition based on isocyanate group containing polyurethane polymers; b) preparing an accelerated adhesive KB1 by mixing the adhesive K and the water containing accelerator composition B into the accelerated adhesive KB1 by means of a static or dynamic mixer, wherein the accelerated adhesive KB1 comprises between 5 and 20 vol.% accelerator composition B based on the entire accelerated adhesive KB1, and then applying the accelerated adhesive KB1 onto the first part T1; c) after step b) preparing an accelerated adhesive KB2 by mixing the adhesive K and the water containing accelerator composition B into the accelerated adhesive KB2 by means of a static or dynamic mixer, wherein the accelerated adhesive KB2 comprises more than 0 vol.% and less than 5 vol.% accelerator composition B based on the entire accelerated adhesive KB2, and then applying the accelerated adhesive KB2 onto the first part T1; wherein the amount of accelerated adhesive KB1 applied onto the first part T1 is less than the amount of accelerated adhesive KB2 applied onto the first part T1; d) joining the second part T2 in bonding position to form a joining seam T12 connecting the first part T1 and the second part T2 by means of the accelerated adhesive KB1 and the accelerated adhesive KB2. The accelerated adhesive KB1 and / or the accelerated adhesive KB2 is applied by means of a handheld application device. The handheld application device is a glue gun. The accelerated adhesive KB1 and / or the accelerated adhesive KB2 is applied by means of an automatic application device having a moving application nozzle. The application device has two separate chambers, wherein the adhesive K and the accelerator composition B are each located in one of the two chambers. The application device further has a mixing chamber, wherein the two separate chambers merge into the mixing chamber and the mixing chamber has a static or dynamic mixer.

2. The method of claim 1, wherein, The accelerated adhesive KB1 is applied discontinuously onto the first part T1.

3. The method of claim 2, wherein, The accelerated adhesive KB1 is applied in a dot-like manner onto the first part T1.

4. The method of claim 1, wherein, An activator, adhesion promoter or primer is applied on the surface to be bonded of the first part T1 and / or the second part T2 prior to the application of the adhesive KB1.

5. The method according to any one of claims 2 to 4, characterized in that, The accelerated adhesive KB1 and / or the accelerated adhesive KB2 is heated before, during or after the application.

6. The method of claim 5, wherein, The accelerated adhesive KB1 comprises between 7.5 and 12.5 vol.% accelerator composition B.

7. The method according to any one of claims 1 to 4, characterized in that, The accelerated adhesive KB2 comprises between 0.5 and 3.5 vol.% accelerator composition B.

8. The method of claim 7, wherein, The accelerator composition B comprises between 10 and 60 wt.% water.

9. The method according to any one of claims 1 to 4, characterized in that, The accelerator composition B comprises between 15 and 40 wt.% water.

10. The method according to any one of claims 1 to 4, characterized in that, The accelerator composition B further comprises at least one polymer and / or at least one acid for the curing of the moisture-curing adhesive.

11. The method according to any one of claims 1 to 4, characterized in that, ​ 12. The method according to any one of claims 1 to 4, characterized in that, ​ 13. The method according to any one of claims 1 to 4, characterized in that, ​ 14. The method of claim 13, wherein, ​ 15. The method according to any one of claims 1 to 4, characterized in that, ​