WO2019042967A1

WO2019042967A1 - Improved method for prefixing and adhering parts

Info

Publication number: WO2019042967A1
Application number: PCT/EP2018/073086
Authority: WO
Inventors: Florian ALTENWEGNER; Dirk Urbach
Original assignee: Sika Technology Ag
Priority date: 2017-09-01
Filing date: 2018-08-28
Publication date: 2019-03-07
Also published as: EP3676344A1; CN111032805A

Abstract

The invention relates to a method for prefixing and adhering two parts T1 and 12, having the steps of: a) providing a single-component moisture-curing adhesive K and an accelerator composition B which contains between 10 and 80 wt.% of water; b) producing an accelerated adhesive KB1 by mixing the adhesive K with a water-containing accelerator composition B in order to form the accelerated adhesive KB1, said accelerated adhesive KB1 containing between 5 and 20 vol.% of the accelerator composition B, and subsequently applying the accelerated adhesive KB1 onto the first part T1; c) producing an optionally accelerated adhesive KB2 by optionally mixing the adhesive K with the water-containing accelerator composition B in order to form the optionally accelerated adhesive KB2, said optionally accelerated adhesive KB2 containing less than 5 vol.% of the accelerator composition B, and subsequently applying the optionally accelerated adhesive KB2 onto the first part T1; wherein the steps b) and c) can be carried out in any order, and the amount of the accelerated adhesive KB1 applied onto the first part T1 is less than the amount of the optionally accelerated adhesive KB2 applied onto the first part T1; and d) joining the second part T2 with the adhesive point such that a composite joint T12 is produced which connects the two parts T1 and T2 via the accelerated adhesive KB1 and the optionally accelerated adhesive KB2. The method according to the invention allows parts which are to be adhered to be prefixed and adhered using a single adhesive without requiring an additional prefixing process and without adversely affecting the resulting adhesion due to a cured mechanically inhomogeneous adhesive. Thus, a faster and better adhesion process is facilitated which can additionally be carried out with less effort.

Description

IMPROVED METHOD FOR PREFIXING AND GLUING PARTS

Technical area

The invention relates to a method for prefixing and bonding of parts which are bonded with moisture-curing compositions.

State of the art

In industrial manufacturing, bonding has long been used to join parts of the article of manufacture. In contrast to other joining techniques, such as screwing or welding, the bonding has the advantage that, in contrast to welding, it can be used universally and, since no boreholes and the like are necessary, does not result in any mechanical weakening or visual impairment of the article of manufacture.

In the interests of an efficient production process, it is sometimes necessary that the parts to be joined, after the adhesive has been introduced into the adhesive joint, be pre-fixed so that the adhesive can harden or build enough strength without slipping the parts. This allows a quick, temporary fixation, resulting in shorter production cycles and a broader range of adhesives.

Mechanical prefixing by suitable devices is not possible in all cases and has the disadvantage that expensive and expensive fixing must be used, which extend the adhesive and thus the entire manufacturing process again. In the case of large components, complete holding devices must be built, which additionally occupy considerable space in the production, which can not be used for other processes. Therefore, in today's industrial manufacturing usually a Vorfixier- bonding is performed. In this case, a very rapidly curing adhesive and / or an adhesive having a very high early strength is usually used, which also produces a stiff and firm adhesive bond between the parts. The adhesives used for this purpose are usually hot-melt adhesives, 2-component acrylate adhesives or pressure-sensitive adhesives (pressure-sensitive adhesives). ves, "PSA") .These have a sufficiently high early strength to immediately hold the prefixed parts without further fixation until the actual adhesive in the adhesive joint has hardened.

The most important limitation of this technique, however, is that in the end, there are two distinctly different adhesives in the adhesive joint in their mechanical properties: the pre-fixing adhesive and the actual adhesive that joins the parts together. The latter adhesive is in most cases an elastic adhesive, e.g. Vibration or thermal movements on the object of manufacture can compensate, which is important for vehicles or household appliances. By contrast, the prefixing adhesive is usually a rigid, high-modulus adhesive because only those processes normally have a sufficiently high early strength. Thus, the bond has an inhomogeneous rigidity. This results in an uneven loading of the adhesive surface under mechanical stress on the bonded production counterpart, whereby the higher modulus components are subjected to greater stress and mechanical damage or undesired effects such as vibrations or deformations can occur. Another disadvantage of using two different adhesives is that it makes the production line more complex and expensive and requires different application devices for the different adhesives.

Another approach is the use of thermosetting or heat-accelerated adhesives for prefixing. It can thus be achieved that the prefixing adhesive, if it is heated upright before, during or after the application, has the required strength fast enough to ensure the prefixing. However, a disadvantage of this method is that, in turn, an additional process step has to be carried out by the heat treatment, which prolongs and increases the cost of production. Moreover, this method can not be used in every case. In particular, in the connection of thermoplastic materials, this is often not possible, since thermally induced deformations can occur on the parts.

Thus, there is a need for a prefixing and bonding method that provides efficient, easy-to-perform pre-fixing by means of adhesive However, but at the end of a bond is obtained, which is homogeneous in terms of their mechanical properties. Another advantage would be a method that is also applicable to heat-sensitive adhesive substrates and can be carried out with technically simple as possible, but versatile means.

Presentation of the invention

It is therefore an object of the present invention to provide a prefixing and gluing method which comprises an efficient, easy to perform pre-fixing by means of adhesive, but at the end a gluing is obtained which is homogeneous in terms of its mechanical properties, in particular stiffness, and which is also applicable to heat-sensitive adhesive substrates and can be performed with technically simple as possible, but versatile means.

According to the invention, this object is achieved by a method according to claim 1.

Surprisingly, it has been found that by using a single moisture-curing adhesive and a single accelerator composition, a multi-stage process can be carried out comprising pre-fixing and actual bonding, both of which can be carried out using the single adhesive and the sole accelerator composition in different mixing ratios , The method according to claim 1 results in that after complete curing of the bond, a mechanically homogeneous adhesive bond is obtained, which despite the simplified application of the disadvantages of the prior art, with different adhesives for prefixing and the actual bonding, not having.

Further aspects of the invention are the subject of further independent claims. Particularly preferred embodiments of the invention are the subject of the dependent claims. Ways to carry out the invention

The present invention relates to methods for prefixing and bonding two parts T1 and T2, comprising the steps:

a) providing a one-component, moisture-curing adhesive K and an accelerator composition B containing between 10 and 80 wt .-% water, based on the accelerator composition B;

b) producing an accelerated adhesive KB1 by mixing the adhesive K with a hydrous accelerator composition B by means of a static or dynamic mixer to the accelerated adhesive KB1, the accelerated adhesive KB1 containing between 5 and 20% by volume of the accelerator composition B, based on the total accelerated adhesive KB1, and then applying the accelerated adhesive KB1 to the first part T1;

c) producing an optionally accelerated adhesive KB2 by optionally mixing the adhesive K with the aqueous accelerator composition B by means of a static or dynamic mixer to the optionally accelerated adhesive KB2, wherein the optionally accelerated adhesive KB2 contains less than 5% by volume of the accelerator composition B. on the entire accelerated adhesive KB2, and then applying the optional accelerated adhesive KB2 on the first part T1;

wherein steps b) and c) are performed in any order and the application amount of the accelerated adhesive KB1 to the first part T1 is less than the application amount of the optional accelerated adhesive KB2 to the first part T1;

d) Joining the second part T2 on the splice, so that a composite joint T12 is formed, which connects the two parts T1 and T2 via the accelerated adhesive KB1 and the optional accelerated adhesive KB2. Substance names starting with "poly", such as polyol or polyisocyanate, in the present document refer to substances which formally contain two or more of the functional groups per molecule occurring in their name.The term "polymer" in the present document comprises, on the one hand, a collective of chemically uniform but one in terms of degree of polymerization, molecular weight and chain length differing macromolecules, which was prepared by a polyreaction (polymerization, polyaddition, polycondensation). On the other hand, the term also encompasses derivatives of such a collective of macromolecules from polyreactions, compounds which have been obtained by reactions, such as additions or substitutions, of functional groups on given macromolecules and which may be chemically uniform or chemically nonuniform. The term also includes so-called prepolymers, that is reactive oligomeric pre-adducts whose functional groups are involved in the construction of macromolecules.

The term "polyurethane polymer" encompasses all polymers which are prepared by the so-called diisocyanate-polyaddition process, including those polymers which are almost or completely free of urethane groups. Polyurethanes, polyether-polyureas, polyureas, polyester-polyureas, polyisocyanurates and polycarbodiimides.

The term "silane-functional polymers" describes silane-group-containing polymers, in particular silane-group-containing organic polymers, which are usually and in this document synonymously also termed "silane-functional polymers", "silane-modified polymers" (SMP) or "silane-terminated polymers Polymers "(STP). Their crosslinking proceeds via the condensation of silanol groups to form siloxane bonds and is conventionally catalyzed by means of organotin compounds, in particular dialkyltin (IV) carboxylates.

The term "silane-containing polyether" also includes silane-containing organic polymers, which in addition to polyether units may also contain urethane groups, urea groups or thiourethane groups. Such silane-containing polyethers may also be referred to as "silane-containing polyurethanes".

In the present document, the terms "silane" or "organosilane" designate compounds which have on the one hand at least one, usually two or three, alkoxy groups or acyloxy groups bonded via Si-O bonds directly to the silicon atom, and at least one, via an Si-C bond, directly to the silicon atom bonded organic radical. Such silanes are also known to the person skilled in the art as organoalkoxysilanes or organoacyloxysilanes.

Accordingly, the term "silane group" refers to the silicon-bonded group attached to the organic group of the silane bound via the Si-C bond The silanes, or their silane groups, have the property of hydrolyzing on contact with moisture nosilanols, that is, organosilicon compounds containing one or more silanol groups (Si-OH groups) and, by subsequent condensation reactions, organosiloxanes, that is, organosiloxanes containing one or more siloxane groups (Si-O-Si groups) The term "silane-functional "denotes compounds which have silane groups." Silane-functional polymers "are therefore polymers which have at least one silane group.

The term "hydroxysilane", "isocyanatosilane", "aminosilane" or "mercaptosilane" denotes organoalkoxysilanes which have one or more hydroxyl, isocyanato, amino or mercapto groups on the organic radical in addition to the silane group.

Amino-silanes which have a primary amino group, that is to say an NHb group which is bonded to an organic radical, are referred to as "primary aminosilanes." Amino-silanes which have a secondary amino group, that is to say an NH group, are referred to as "secondary aminosilanes". which is bound to two organic radicals.

By "molecular weight" is meant in this document the molar mass (in grams per mole) of a molecule or part of a molecule, also referred to as "residue". By "average molecular weight" is meant the number average Mn of an oligomeric or polymeric mixture of molecules or residues. th, which is usually determined by gel permeation chromatography (GPC) against polystyrene as a standard.

A "stable substance" or "composition" is defined as a substance or composition which may be stored at room temperature in a suitable dressing for a prolonged period of time, typically at least 3 months to 6 months or more, without being present in its own state Use or performance, in particular the viscosity and the rate of crosslinking, changed by the storage in a relevant for their use to the extent.

The term "room temperature" refers to a temperature of approx. 23 ° C.

All industry standards and standards mentioned in the document refer to the version in force at the time of filing of the initial application, unless otherwise stated.

The terms "mass" and "weight" are used interchangeably throughout this document. Thus, a "weight percent" (% by weight) refers to a percentage by weight which, unless otherwise stated, refers to the mass (weight) of the total composition, or to the context of the entire molecule.

The term "open time" describes the time during which two parts to be bonded can still be joined without problems after the adhesive has been applied and begins to harden.

The process according to the invention comprises the provision of a one-component, moisture-curing adhesive K. It contains at least one moisture-crosslinkable polymer. "Monocomponent" means that the adhesive is admixed without admixing further components solely by moisture, for example from air, and optionally by feeding In one embodiment of the invention, the crosslinkable polymer is an isocyanate group-containing polyurethane polymer which is obtainable, in particular, by the reaction of at least one polyol with at least one polyisocyanate. Particularly suitable as polyol are polyether polyols, polyester polyols, polycarbonate polyols, polyacrylate polyols and hydrocarbon polyols, preferably polyether polyols. Preferred polyether polyols are polyoxypropylene polyols and polyoxypropylene polyoxyethylene polyols, in particular the diols and triols. Suitable polyisocyanates are in particular diisocyanates. Preferred diisocyanates are 1,6-hexamethylene diisocyanate (HDI), 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane (isophorone diisocyanate or IPDI), perhydro 2,4'- and -4,4'-diphenylmethane diisocyanate (HMDI or H12MDI), 2,4- and 2,6-toluene diisocyanate and any mixtures of these isomers (TDI) and 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate and any mixtures of these isomers (MDI ).

The polyurethane polymer is prepared in a known manner. It has a molecular weight of 500 to 50Ό00 g / mol, preferably between

1000 and 30Ό00 g / mol, on. Furthermore, the polyurethane polymer preferably has an average NCO functionality of 1.8 to 3.

In a further embodiment of the invention, the crosslinkable polymer is a silane-functional polymer, in particular a silane-terminated polyether, a silane-terminated poly (meth) acrylate or a silane-terminated polyurethane. Such polymers are in particular obtainable by reacting a polyol with an isocyanatosilane, by reacting an isocyanate group-containing prepolymer with an amino, hydroxy or mercaptosilane, by reacting a polyamine with a (meth) acrylsilane or by reacting a (meth) acryl-terminated polymer with an amino or mercaptosilane.

A preferred silane-functional polymer is the reaction product of an optionally chain-extended, isocyanate-group-terminated polymer with an aminosilane, in particular a secondary aminosilane. Preferred secondary aminosilanes for this reaction are alkylaminosilanes, for example a 3- (n-butylamino) propylalkoxysilane or a

Bis (alkoxysilylpropyl) amine and in particular Michael adducts of primary aminosilanes with Michael acceptors such as acrylonitrile, (meth) acrylates and maleic acid esters and amides. Preferred Michael adducts are the conversion cationic products of primary aminosilanes, in particular 3-aminopropylalkoxysilanes, with acrylates, for example n-butyl acrylate or isobornyl acrylate, and in particular maleic acid dialkyl esters. Most preferred are the Michael adducts of 3-aminopropyl-dialkoxyalkylsilanes or 3-aminopropyltrialkoxysilanes with maleic acid dialkyl esters, especially diethyl malonate.

The silane groups are in particular dialkoxyalkylsilane groups and preferably trialkoxysilane groups. Preferred alkoxy groups on the silane groups are ethoxy groups and especially methoxy groups.

For example, suitable silane-functional polymers are commercially available under the trade name Polymer ST, for example polymer ST50 from the company Hanse Chemie AG, Germany, and under the trade name Desmoseal ^® from Bayer MaterialScience AG, Germany.

Other suitable silane-functional polymers are commercially available under the trade names SPUR + ^® 1010LM, 1015LM and 1050MM from the company Momentive Performance Materials Inc., USA, and under the trade names Geniosil® ^® STP-E15, STP-10 and STP-E35 from Wacker Chemie AG, Germany.

Also suitable are silane-functional polymers commercially available under the trade names MS Polymer ™ S203H, S303H, S227, S810, MA903 and S943, Silyl ™ SAX22Q, SAX350, SAX400 and SAX725, Silyl ™ SAT350 and SAT400, and XMAP ™ SA100S and SA310S by the company Ka neka Corp., Japan, and sold under the trade name Excestar ^® S24 0, S2420, S3430, S3630, W2450 and MSX931 of Asahi Glass Co, Ltd., Japan.

In the described adhesives K, in particular if they have been prepared on the basis of polyurethane polymers or of silane-functional polymers, the following well-known auxiliaries and additives may, in addition, inter alia be present:

Plasticizers, for example esters of organic carboxylic acids or their anhydrides, phthalates, such as, for example, dioctyl phthalate or diisodecyl phthalate, Adipates such as dioctyl adipate, sebacates, organic phosphoric and sulfonic acid esters, polybutenes and other isocyanate-unreacted compounds; Reactive thinner and crosslinker, for example polyhydric alcohols, polyamines, polyaldimines, polyketimines or aliphatic isocyanates such as 1, 6-hexamethylene diisocyanate, 2,2,4- and 2,4,4-trimethyl-1, 6-hexamethylene diisocyanate, 1, 12-dodecamethylene diisocyanate , Cyclohexane-1, 3- and 1, 4-diisocyanate and any mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane

(= isophorone diisocyanate or IPDI), perhydro-2,4'- and -4,4'-diphenyl methane diisocyanate, 1, 3- and 1, 4-tetramethylxylylene diisocyanate, isocyanurates of these isocyanates, oligomers and polymers of these isocyanates and their adducts with polyols ; inorganic and organic fillers, such as, for example, ground or precipitated calcium carbonates, which are optionally coated with stearates, in particular finely divided coated calcium carbonate, Russian, kaolins, aluminum oxides, silicas and PVC powders or hollow spheres; Fibers, such as polyethylene; pigments; Catalysts such as organotin compounds such as dibutyltin dilaurate, dibutyltin dichloride, dibutyltin diacetylacetonate, bismuth organic

Compounds or bismuth complexes, or amine group-containing compounds such as 2,2'-Dimorpholinodiethylether, or other catalysts commonly used in polyurethane chemistry and silane chemistry for the reaction of the isocyanate groups or alkoxysilane groups; further catalysts for the hydrolysis of the polyaldimine, if any, such as organic carboxylic acids such as benzoic or salicylic acid, an organic carboxylic anhydride such as phthalic anhydride or hexahydrophthalic anhydride, a silyl ester of organic carboxylic acids, an organic sulfonic acid such as p-toluenesulfonic acid or 4-dodecylbenzenesulfonic acid, or a other organic or inorganic acid, or mixtures of the aforementioned acids; Rheology modifiers such as thickeners, for example urea compounds, polyamide waxes, bentonites or fumed silicas; Bonding agents, in particular silanes, such as epoxysilanes, vinylsilanes, isocyanatosilanes and aminosilanes reacted with aldehydes to give aldiminosilanes, and also oligomeric forms of these silanes; Desiccants such as p- Tosyl isocyanate and other reactive isocyanates, orthoformic acid esters, calcium oxide or molecular sieves; Stabilizers against heat, light and UV radiation; flame-retardant substances; surfactants such as wetting agents, leveling agents, deaerators or defoamers; Fungicides or fungal growth inhibiting substances; as well as other substances commonly used in the production of moisture-curing compositions, it being clear to the person skilled in the art whether these additional substances are suitable as additives for the particular adhesive. Particularly suitable adhesives K are one-component, moisture-curing compositions based on isocyanate-functional polyurethane polymers or silane-functional polymers. Such compositions are commercially available from Sika AG Switzerland, for example, under the trade name of Sikaflex ^® or SikaBond ^®.

The inventive method further comprises the provision of an accelerator composition B, which contains between 10 and 80 wt .-% water, based on the accelerator composition B. Preferably, the accelerator composition B contains between 10 and 60 wt .-% water, in particular between 15 and 40 wt % Of water, based on the total accelerator composition B.

The accelerator composition B initially contains at least water. In order to obtain a good incorporation of the water into the accelerator composition B, it is advantageous if the accelerator composition B contains a carrier which, on the one hand, reduces the viscosity of the

Accelerator composition B increases and on the other hand advantageously influenced the mixing ratio. Due to the small amount of water needed for the accelerated cure, and such a small interference can at best lead to problems of homogeneous interference, the use of a carrier material, the volume ratio of adhesive K to accelerator composition B is reduced, so that reduces the mixing problems become. Furthermore, it is known that the mixing of two in the Viscosity drastically different components is associated with difficulties. This difficulty is reduced by the use of a carrier material. The carrier material is advantageously an organic polymer having ionic groups. Such ionic groups are in particular carboxylic acid group and / or sulfonic acid groups. On the one hand advantageous as such organic polymers are poly (meth) acrylic acids and copolymers of (meth) acrylic acids. Particularly advantageously, the support material is a polyurethane having at least one carboxylic acid group and / or sulfonic acid group. Particularly suitable as support materials are polyurethanes, for the synthesis of which carboxylic acid-containing diols, in particular dimethyloipropanecarboxylic acid, and polyisocyanates are used. Using such carrier materials, the water is reversibly bound by the carrier material with ionic groups and forms a gel-like paste.

The amount of water relative to the moisture-reactive groups may be from substoichiometric to superstoichiometric, particularly suitable is a ratio of the reactive groups [H 2 O] / [NCO] or [H 2 O] / [silicon-bonded alkoxy] from 1 to 3.0, especially 1 to 2.6. Stoichiometric is preferred, in particular with a ratio of 1 to 2.

There are other ways to formulate a water paste. In this case, water with fine fillers such as fumed silica, such as Aerosil ^® , available from Degussa, or chalk or molecular sieves. In this case, the filler is reversibly bound by the water at the surfaces or in the pores.

However, preferred carriers are organic polymers with ionic groups.

Water pastes with organic polymers which contain ionic groups and can be used for the use according to the present invention as accelerator composition B, are basically already known and are, for example, Sikaflex®-254 or SikaTack®-Plus, which are one-part warmmelt polyurethane adhesives, im Sikaflex®-254 Booster System or SikaTack®-Plus Booster System added. It may be advantageous if the accelerator composition B contains, in addition to water, additionally polyols and / or polyamines. This can, for example, lead to the hardening being done even faster and the final strength being reached faster.

The water may be present in the accelerator composition B either as free water or it may be bound to a carrier material. However, the bond must be reversible, that is, the water must be accessible after mixing the adhesive K and the accelerator composition B for reaction with the moisture-reactive groups in the adhesive K, in particular isocyanate groups, alkoxy groups and / or aldimine.

Suitable support materials for the accelerator composition B may be hydrates or aquo complexes, in particular inorganic compounds which have bound water in a coordinative manner or as water of crystallization. Examples of such hydrates are Na ₂ SO 4 .10H ₂ O, CaSO 4 .2H ₂ O,

Na ₂ B ₄ O 7-10H ₂ O, MgSO ₄ .7H ₂ O.

Other suitable carrier materials are porous materials which trap water in cavities. In particular, these are special silicates and zeolites. Particularly suitable are kieselguhr and molecular sieves. The size of the cavities should be chosen so that they are optimal for the absorption of water. This is why molecular sieves with a pore size of 4 A are particularly suitable.

Further suitable support materials are those which absorb water in non-stoichiometric amounts and have a pasty consistency or form gels. These support materials may be inorganic or organic in nature. Examples thereof are silica gels, clays such as montmorillonite, bentonite, hectorite, or polysaccharides such as cellulose and starch, or polyacrylic acids and polyacrylonitriles, which are also known by the term "superabsorber" and are used, for example, in hygiene articles Polyurethane polymers with carboxyl groups or sulmen are particularly preferred as carrier materials. Fonsäuregruppen as side chains or their salts, in particular their ammonium salts. These carrier materials can absorb and bind water until the water absorption capacity is exhausted.

The particularly preferred polyurethane polymers with carboxyl groups or sulfonic acid groups as side chains, or their salts, can be obtained, for example, from polyisocyanates and polyols which contain carboxylic acid or sulfonic acid groups. The acid groups can then be neutralized, for example in the fully reacted state, with bases, in particular tertiary amines. The properties of the support material are highly dependent on the functional polyols and polyisocyanates used. In particular, attention must be paid to the hydrophilicity or hydrophobicity of the selected isocyanates and polyols. It has been shown that especially short-chain polyols give very suitable support materials. Preferably, the accelerator composition B, when used in conjunction with a polyurethane adhesive, also contains at least one poly-dimine. The polyaldimine can be prepared from at least one polyamine having aliphatic primary amino groups and at least one aldehyde by a condensation reaction with elimination of water. Such condensation reactions are well known and described, for example in Houben-Weyl, "Methods of Organic Chemistry", Vol. XI / 2, page 73 ff. These are equilibrium reactions, the equilibrium being predominantly on the side of the That is, when a polyamine having aliphatic primary amino groups is mixed with at least a stoichiometric amount of an aldehyde, the corresponding polyaldimine is spontaneously formed, regardless of whether or not it is in the reaction

eliminated water is removed from the reaction mixture or not.

Suitable polyamines having aliphatic primary amino groups for the preparation of the polyaldimine are the polyamines known in polyurethane chemistry, such as are used, inter alia, for two-component polyurethanes. 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-xylylenediamine , 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, polyoxyalkylene polyamines having theoretically two or three amino groups, especially Jeffamine ^® EDR-148, Jeffamine ^® D-230, Jeffamine ^® D-400 and Jeffamine ^® T-403, as well as in particular mixtures of two or more of the aforementioned polyamines.

It is advantageous if at least the amount of water required for complete conversion of the polyaldimine possibly present into the polyamine is present in the accelerator composition B. That is, the accelerator composition B preferably contains at least as much water as equivalent aldimine groups, or in other words: the accelerator composition B preferably has at least one molecule of water per aldimine group. Preferably, the accelerator composition B further contains at least one external emulsifier, in particular a nonionic emulsifier, for example a fatty alcohol ethoxylate.

The accelerator composition B preferably has an emulsifier content of <10% by weight, in particular <5% by weight.

Furthermore, the accelerator composition B optionally contains in particular a rheology aid or a filler, in particular pyrogenic silicic acids and ureas.

The accelerator composition B preferably additionally contains, in particular, additionally at least one polymer and / or at least one acid and / or at least one catalyst for the curing of moisture-curing adhesives. The said polymer comprises in particular a water binding polymer, as described above, a polyol for reaction with isocyanate-containing prepolymers, if contained in the adhesive, or a polyaldi- min as described above. In step b) of the process according to the invention, the adhesive K with the accelerator composition B is mixed by means of a static or dynamic mixer into an accelerated adhesive KB1, the accelerated adhesive KB1 containing between 5 and 20% by volume of the accelerator composition B, based on the total accelerated Adhesive KB1.

In step c) of the method according to the invention, the adhesive K with the accelerator composition B is optionally mixed by means of a static or dynamic mixer to form an optionally accelerated adhesive KB2, wherein the optionally accelerated adhesive KB2 is less than 5

Volume% of accelerator composition B contains, based on the total accelerated adhesive KB2. The optionally accelerated adhesive KB2 is purely optional accelerated; it can also consist purely of the adhesive K. Whether additionally at most 5% by weight of accelerator composition B is mixed in depends essentially on the desired bonding process and the associated cycle times. However, admixture of accelerator composition B is preferred if the method permits, since such a shortening of the curing time can be achieved.

The mixing of the adhesive K with the accelerator composition B is advantageously carried out continuously throughout the process during the application. In one possible embodiment, the mixing of the adhesive K with the accelerator composition B takes place by means of a metering attachment containing two intermeshing metering rotors. Such preferred metering attachments are described in detail in the patent EP 0 749 530. The dosing attachment is preferably designed for smaller applications

commercially available cartridge containing the adhesive K, while the accelerator composition B is in a container which is integrated in the dosing. The dosage and mixture takes place at the Application in this dosing attachment, which is passively operated by the pressurization of the cartridge, for example by means of a commercially available cartridge press. For better mixing, a static mixer can additionally be attached to the outlet opening of this dosing attachment.

Another possibility for mixing the adhesive K with the accelerator composition B are commercially available so-called twin cartridges or so-called coaxial cartridges, each with a static mixer attached to the outlet opening. When twin cartridges are used, the adhesive K and the accelerator composition B are in separate cartridges attached to one another, which open into a common outlet opening. The application takes place by means of a suitable squeezing device, which squeezes both cartridges in parallel. When using coaxial cartridges, one of the two components is located in the core of the cartridge. The other component encloses them, the components being separated by a coaxial wall. The two components are also pressed out at the same time by a suitable Auspressvorrichtung in the application and open into a common

Austrittsöffung.

In one embodiment, these are dual cartridges, as are known from two-component adhesives, wherein the arrangement of the chambers can be configured differently. For example, these may be cylindrical chambers, which may be arranged side by side or co-centric. The walls of the chambers can be rigid or flexible. An exemplary arrangement of the chambers and their configuration can be found in WO 01/44074 or in US 6,433,091 B1.

For industrial applications, on the other hand, it is advantageous to use the adhesive K and the accelerator composition B from drums or hobbock containers. In this case, the adhesive K and the accelerator composition B are advantageously mixed with a dosing attachment, which is essentially characterized by the dosing attachment described above distinguishes that it has a hose connection for the accelerator composition B.

In one embodiment, the accelerator composition B may be present in a package from which the accelerator composition B is metered and admixed with a stream of adhesive K. An example of such a packaging or metering can be found, for example, in WO 95/24556. Such packaging / dosing devices are advantageously screwed onto a cartridge outlet or onto an outlet opening of an adhesive pump.

In a further embodiment, the admixture of the accelerator composition B to the adhesive K and mixing by means of a dynamic mixer.

In a further embodiment, the accelerator composition B is injected to the adhesive K, in particular via a plurality of distributed nozzles and then mixed.

The admixture of the accelerator composition B in the adhesive K can be homogeneous or in layers. Layers are obtained in particular when a small number, typically between 3 and 10, of mixing elements are arranged in a static mixer.

If a homogeneous mixing is desired, preferably either a dynamic mixer or a plurality of mixing elements, typically more than 12, in particular more than 15 mixing elements, are used in a static mixer. Preference is given to a substantially homogeneous mixing. If the accelerator composition B and the adhesive K are mixed essentially in layers, for example by working with a static mixer with a small number of mixing elements, then after complete curing, a homogenously through-hardened product is usually still produced, in which the original layers are no longer visible.

During and after mixing of the accelerator composition B and the adhesive K, the moisture-curing adhesive reacts over the contained one crosslinkable polymers with the water and / or with a hydrolyzed reagent, for example a hydrolyzed form of the polyaldimine possibly contained. Over all the reactions, the adhesive K hardens after application. In addition, there may be a subsequent reaction with water which is taken up from the air (atmospheric moisture), which leads at most to a further, complete aftercuring of the adhesive K.

In a preferred embodiment of the method, the accelerated adhesive KB1 and / or the optionally accelerated adhesive KB2 are applied by means of a hand-guided applicator device, in particular a gun. The mixing of the accelerator composition B and the adhesive K can be carried out directly in the applicator device, as described above. In another preferred embodiment of the method, the accelerated adhesive KB1 and / or the optionally accelerated adhesive KB2 are applied by means of an automatic applicator device which has a movable application nozzle. The mixing of the accelerator composition B and the adhesive K can take place directly in the applicator device, as described above.

The applicator device in the aforementioned two preferred methods preferably comprises two separate chambers, wherein the adhesive K and the accelerator composition B are each located in one of the two chambers.

Furthermore, the applicator device preferably additionally comprises a mixing chamber into which both chambers open and which comprises a static or dynamic mixer. The application of the accelerated adhesive KB1 and the optional accelerated adhesive KB2 can be carried out in the same or different ways. With regard to the application amount, however, it is advantageous if the accelerated adhesive KB1 is applied in the smallest possible amount, so that straight sufficient adhesive is present that the pre-fixing of the two parts to be bonded T1 and T2 is ensured without further fixation measures. This is preferably done with respect to statics critical points that are exposed during the movement of the bonded parts T1 and T2 particularly large forces. The minimum amount of accelerated adhesive KB1 required in a specific bonding process essentially depends on the weight and the geometry of the parts to be bonded as well as on the mechanical properties of the adhesive K and can easily be determined by a person skilled in the art by routine tests.

A preferred embodiment of the method according to the invention comprises the following steps in the order indicated:

1) providing a one-component, moisture-curing adhesive K and an accelerator composition B containing between 10 and 80% by weight of water, based on the accelerator composition B;

2) making an optional accelerated adhesive KB2 by optionally mixing the adhesive K with the aqueous accelerator composition B by means of a static or dynamic mixer to the optionally accelerated adhesive KB2, wherein the optional accelerated adhesive KB2 contains less than 5% by volume of the accelerator composition B. on the entire accelerated adhesive KB2;

3) applying the optional accelerated adhesive KB2 to the first part T1;

4) producing an accelerated adhesive KB1 by mixing the adhesive K with a hydrous accelerator composition B by means of a static or dynamic mixer to the accelerated adhesive KB1, wherein the accelerated adhesive KB1 is between 5 and 20% by volume of the accelerator composition

B contains, based on the total accelerated adhesive KB1; 5) applying the accelerated adhesive KB1 to the part T1, wherein the application amount of the accelerated adhesive KB1 is less than the application amount of the optional accelerated adhesive KB2;

6) Joins the second part T2 on the splice, so that a composite joint T12 is formed, which connects the two parts T1 and T2 via the accelerated adhesive KB1 and the optional accelerated adhesive KB2.

In a preferred embodiment, the optionally accelerated adhesive KB2 is first applied to the first part T1 and then, during the open time of the optionally accelerated adhesive KB2, the accelerated adhesive KB1 is not continuously applied to the first part T1. This is preferably a punctiform application of the accelerated adhesive KB1, wherein the accelerated adhesive KB1 is applied next to or between the optionally accelerated adhesive KB2 on the first part. Such a application produces a composite joint T12, which has an optionally accelerated adhesive KB2 applied over a large area and accelerated adhesive KB1 applied punctiform or in between or next to it. In another preferred embodiment, the accelerated adhesive KB1 is applied in thin beads applied adjacent to or between the optional accelerated adhesive KB2, with less than half of the gap between the parts T1 and T2 being filled by accelerated adhesive KB1.

It would also be possible, depending on the type and geometry of the parts T1 and T2 to be bonded, first to apply the accelerated adhesive KB1, to add the parts, and only then to inject the optionally accelerated adhesive KB2 into the cavities of the resulting partial composite joint. Thus, a pre-fixing could be achieved via KB1, even before the optional accelerated adhesive KB2 is applied. However, this method requires a complex injection step, which is not always feasible. In all cases of the process according to the invention, the adhesive in the T12 composite joint must consist of less than half of the accelerated adhesive KB1 and more than half of the optionally accelerated KB2 adhesive. Preferably, the total adhesive in the T12 composite joint is at most 25%, based on the area of the applied adhesives KB1 and KB2, of accelerated adhesive KB1 and at least 75% of optionally accelerated adhesive KB2. More preferably, the total adhesive in the composite joint T12 is at most 10%, based on the area of the applied adhesives KB1 and KB2 of accelerated adhesive KB1 and at least 90% of optionally accelerated adhesive KB2.

In some embodiments of the method, it may be advantageous to apply an activator, adhesion promoter or primer to the adherend surface of the part T1 and / or the part T2 before applying the adhesive KB1 and / or the adhesive KB2.

In some embodiments of the method, it may further be advantageous for the accelerated adhesive KB1 and / or the adhesive KB2 to be heated before, during or after application. This speeds up the buildup of the strength of the adhesive and shortens the open time.

In the blending and application of the optional accelerated adhesive KB2, the accelerator composition B is preferably used in such a ratio to the adhesive K that with the water present in the accelerator composition B at least 50%, preferably 100%, of all reactive groups of the crosslinkable polymer throughout is optional accelerated adhesive KB2 can be implemented. However, it is also possible to apply the optionally accelerated adhesive KB2 entirely without admixing the accelerator composition B. In these cases, it hardens only by water from the environment, such as humidity. In a preferred embodiment of the method, the optionally accelerated adhesive KB2 contains between 0.5 and 5% by volume of the accelerator composition B. In the mixing and application of the accelerated adhesive KB1, the accelerator composition B is preferably used in a ratio to the adhesive K that corresponds to that in FIG 100% of all of the crosslinkable polymer reactive groups can be reacted throughout the accelerated KB1 adhesive. It is possible to use a molar excess of water with respect to the moisture-reactive groups of the adhesive. The excess of water causes an additional acceleration of the curing of the accelerated adhesive KB1.

In a preferred embodiment of the method, the accelerated adhesive KB1 contains between 7.5 and 12.5% by volume of the accelerator composition B.

After the application of the accelerated adhesive KB1 and the optional accelerated adhesive KB2 and joining of the parts T1 and 12, a composite joint T12 is created which connects the two parts T1 and T2 via the accelerated adhesive KB1 and the optionally accelerated adhesive KB2.

Due to the different content of water in the accelerated adhesive KB1 and KB2 in the optionally accelerated adhesive a different open time of the two blends KB1 and KB2 is achieved, the accelerated adhesive KB1 has a shorter open time and faster early strength builds. Surprisingly, this has no significant influence on the mechanical values, in particular stiffness and modulus, of the adhesive K after complete curing. Both the accelerated adhesive KB1 and the optional accelerated adhesive KB2 have, after complete curing, very similar mechanical properties, in particular with regard to modulus, tensile strength and elongation at break, as well as the same adhesive properties. The contact of the accelerated adhesive KB1 and the optional accelerated adhesive KB2 with water in the form of humidity is not absolutely necessary for the curing, if in both cases water in the form of

Accelerator composition B was added, but it can also favor. In particular, the postcuring of the composition can be carried out by means of atmospheric moisture.

The curing of the accelerated adhesive KB1 and the optionally accelerated adhesive KB2 takes place especially at room temperature. In certain cases, it may be advantageous to subsequently or completely cure the partially cured composition with the aid of elevated temperature, for example in the range from 40 to 100.degree. It may also be advantageous to heat the accelerated adhesive KB1 and the optional accelerated adhesive KB2 before, during or after application. This has the advantage that by lowering the viscosity of the pumpability and application is simplified and also that the curing is accelerated.

In particular, the curing of the accelerated adhesive KB1 is such that, on the one hand, a sufficient open time is ensured and, on the other hand, curing has progressed within a period of a few minutes, or if rapid strength is built up so rapidly that the prefixing can be processed further or a bond carried out with the accelerated adhesive KB1 is self-supporting and can be transported.

With the described method using the accelerated adhesive KB1 and the optionally accelerated adhesive KB2, it is possible to formulate a modular (prefabricated) prefixing and bonding system which requires only a single adhesive K and a single accelerator composition B. Depending on the requirements of an application, different mixing ratios of adhesive K and accelerator composition B can be used to produce the accelerated adhesive KB1 and the optional accelerated adhesive KB2. With such a system, the process parameters such as processing times (pot lives, open times), early strengths and curing rates can be easily adapted to the respective desired production process without having to change the adhesive K and the accelerator composition B. This is very advantageous, for example, for the industrial production of smaller quantities, since in this way no essential conversion work on the production line has to be made for another production product and there is no need to stock a whole series of adhesives.

The method according to the invention is suitable for the prefixing and bonding of various substrates, for example for bonding components in the production of automobiles, rail vehicles, ships or other industrial goods, but also for sealing joints in construction.

The method according to the invention is preferably used for adhesive and sealing applications in the construction and manufacturing industry and in vehicle construction, in particular for joint sealing, parquet bonding, bonded part bonding, seam sealing, cavity sealing, assembly,

Body bonding, windshield bonding, roofing, etc. It is particularly advantageous if faster curing of a moisture-curing composition than by air alone is desired, for example, because of a short cycle time in a bonding process or likeliest short waiting time in a repair case, because of processing unfavorable climatic conditions such as winter or desert climate, because of low water vapor permeability of the composition and / or the substrates, because of thick-layered adhesive joints or because of an unfavorable for the access of humidity adhesive geometry.

In particular, the inventive method for bonding substrates made of concrete, mortar, brick, brick, ceramics, gypsum, natural stone such as granite or marble, glass, glass ceramic, metal or metal alloy such as Aluminum, steel, non-ferrous metal, galvanized metal, wood, plastic such as PVC, polycarbonate, polymethyl (meth) acrylate, polyester, epoxy resin, composite materials, paint or varnish. Furthermore, the invention relates to a product comprising at least two parts bonded together, obtained by a method as described above. In particular, this product (article) is a building, an industrial good or a means of transport, or a part thereof.

An exemplary list of such articles are houses, glass facades, windows, bathrooms, kitchens, roofs, bridges, tunnels, roads, automobiles, trucks, rail vehicles, buses, ships, mirrors, windows, tubs, white goods, household appliances, dishwashers, washing machines, Ovens, floodlights, fog lights or solar panels such as photovoltaic or solar thermal modules.

The substrates to be bonded comprising the first part T1 and the second part T2 may be made of a variety of materials. In particular, plastics, organic materials such as leather, fabrics, paper, wood, resin bonded wood materials, resin Texti I-Co m positive material e, glass, porcelain, ceramics and metals, especially painted metals are suitable.

Particularly suitable plastics are polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene copolymers (ABS), SMC (sheet molding composites), polycarbonate (PC), polyamide (PA), polyester (PE), polyoxymethylene (POM), Polyolefins, in particular polyethylene (PE) or polypropylene (PP), preferably PP or PE surface-treated with plasma, corona or flame.

Preferred materials for the substrates, comprising the first part T1 and the second part T2, are metals and polyolefins, in particular painted metals and polypropylene or polyethylene surface-treated with plasma, corona or flame.

The accelerated adhesive KB1 and the optional accelerated adhesive KB2 are particularly suitable as assembly adhesives. As a "mounting adhesive" is referred to in this document, an adhesive, which is a fast Strength structure has, so that it is suitable to glue parts that must be moved after a short time after the adhesive application already. In particular, the accelerated adhesive KB1 must therefore be able to transfer forces between the joining partners after a short time. Typically, assembly adhesives are used in industrial manufacturing, especially in a conveyor belt process. Particularly preferred is the use of the adhesive in construction of means of transport, in particular of vehicles, more preferably of automobiles.

Thus, for example, prefabricated modules can be prefixed and glued to a body of a vehicle using the method according to the invention.

Examples

In the following, exemplary embodiments are listed which are intended to explain the described invention in more detail. Of course, the invention is not limited to these described embodiments.

Description of the measuring methods

The tensile strength, the elongation at break, and the modulus of elasticity ("modulus of elasticity") in the range 0.5-5% elongation were determined according to DIN EN ISO 527 (tensile speed: 200 mm / min, test specimen 5A) to dumbbells with a length of 75 mm, with a web length of 30 mm and a web width of 4 mm, which were produced by punching out of films of about 2 mm thickness of the adhesives KB1 and KB2 cured in the standard climate.

Examination of the tensile shear strength was performed using the following method: for each measurement in each case 2 CDL Iackierte steel sheets of 0.8 mm thickness, 25 mm width and 100 mm length were (steel DC04 coated with BASF Catho- Guard ^® 800, available from Rocholl GmbH, Schonbrunn , Germany) with isohexane. After a flash off time of 10 minutes, the wafers were placed against each other with a suitable PTFE mold at a vertical distance of 2 mm so that they overlapped at the head ends by 12.5 mm. The overlap area between the platelets was adhesive filled, which came to lie on the degreased sides of the platelets. The thus glued together platelets were stored at 23 ° C and 50% relative humidity and after 24 hours with the aid of a tensile tester (Zwick) at a constant Querjochgeschwindigkeit of 10 mm / min according to DIN EN 1465 pulled apart until breakage and the breaking load in MPa A second series of measurements ( "aged") (N / mm ²⁾ is measured ( "standard"). was stored after the bonding of the platelets for 7 days in water (deionized water containing <5 pS / cm), then for 24 h at 80 Stored, then stored for 7 days at 70 ° C and 95% relative humidity and then stored for 7 days at 100 ° C. All specimens were conditioned for 2 hours at 23 ° C and 50% relative humidity prior to measurement. The values given are mean values from two measurements. The fracture pattern is given in parentheses ("CF" means completely cohesive failure).

The open time was determined as follows: For each measurement of a measurement series, a triangular bead of the respective adhesive with a width of 10 mm and height of 10 mm under standard conditions (23 ° C., 50% rh) was applied to a cleaned and degreased glass plate (40 × 100 × 6 mm) are applied centrally and along the long side and, after a defined waiting time of 1, 3, 5 and 10 minutes (depending on the measurement), introduced into the sample holder of a Zwick Roell Zwicki 1020 testing machine. In the testing machine was a second glass plate, which was mounted horizontally parallel above the first plate with the adhesive, with a sufficiently large gap that the triangular caterpillar was not touched. Thereafter, a vertical pressure was applied to the triangular bead by the testing machine by moving the second glass plate toward the first one. The speed at which the second plate was moved to the first was always 200 mm / min. It recorded the force required to compress the respective triangular caterpillars to a thickness of 5 mm. When this measured force reached or exceeded 10 N / cm (N per cm of bead length), this was considered to be the end of the open time of the adhesive as measured by the amount of time the sample was allowed to cure prior to measurement (1 to 10 minutes). The time to reach the minimum necessary early strength, ie the curing time, which is required until a bond can be charged without further fixation, was determined by the following method: On a vertically hanging, KTL-coated steel sheet of 0.8 mm thickness, 500 mm length (horizontal) and width of 200 mm (vertical) (material: steel DC04 coated with BASF CathoGuard ^® 800, available from Rocholl GmbH, Schonbrunn, Germany) has a rectangular PTFE disk with thickness of 1 cm over the entire length of the steel sheet was attached , At right angles between the steel plate and the PTFE disc, an adhesive bead was applied over the entire length of the right angle. Immediately thereafter, and within the open time of the adhesive, smaller KTL-coated steel plates of the same 0.8 mm thick, 60 mm long and 25 mm wide material were pressed parallel to each other with their length vertically downwards onto the adherend at 2 cm intervals so that at each Platelet was an adhesive area of 25 x 20 mm and 3 mm thick (achieved by a placeholder), the upper edge of each plate touched the PTFE disc. In the non-bonded area, the sheet steel plates had a hole. After a time defined according to the experiment, each individual plate was loaded with a weight of 500 g placed over the hole. An individual time was chosen for each tile. If, after application of the weight, movement of the plate down within 10 minutes had become visible, the early strength in this experiment had not yet been reached after the respective time. The time to reach the minimum required early strength was the waiting time of the first attempt, the 10 minutes after attaching the weight made no movement in the plate visible.

For the determination of the adhesion, adhesive beads were applied to the corresponding substrates, exposed to different storage conditions and then at room temperature (23 ° C.) and 50% relative

Humidity is checked by means of a "caterpillar test", where the caterpillar is cut just above the adhesive surface at the end of the caterpillar, and the incised end of the caterpillar is held in place with circular tongs and pulled from the substrate. This is done by carefully rolling up the bead on the point of the pliers, and by placing a cut to the bare ground perpendicular to the caterpillar pulling direction. The caterpillar removal speed should be selected so that a cut must be made approx. Every 3 seconds. The test track must be at least 8 cm. It is assessed after the removal of the caterpillar on the substrate remaining adhesive

(Cohesive failure). The assessment of the adhesive properties is carried out by estimating the cohesive part of the adhesive surface:

1 => 95% cohesive failure; 2 = 75 - 95% cohesive failure; 3 = 25 - 75% cohesive failure; 4 = <25% cohesive failure; 5 = 0% cohesive failure (purely adhesive fracture). Test results with cohesive failure values of less than 75% are considered insufficient.

As the first substrate ( "substrate 1") were CDL Iackierte steel plate of 0.8 mm thickness, 25 mm width and 100 mm length (steel DC04 coated with BASF CathoGuard ^® 800, available from Rocholl GmbH, Schonbrunn, Germany), the front was cleaned with isopropanol and flashed for 10 min.

As a second substrate ("Substrate 2"), the same cleaned platelets were used, which in this case, however, were treated with SikaPrimer-207 and flashed for 10 minutes before application of the adhesive. relative humidity ("7d RT"), in addition to 7 days in a water bath at 20 ° C ("7d water"), in addition to 1 day at 80 ° C and 50% relative humidity ("d 80 ° C"), in addition 7 Days Cataplasmal storage at 70 ° C and 100% relative humidity ("7d cataplasm") and finally 7 days at 100 ° C ("7d 100 ° C").

Moisture-curing compositions

Adhesive K: As a one-component, moisture-curing adhesive K is a polyurethane adhesive Sikaflex ^® -270 was used (available from Sika Switzerland AG). Accelerator Composition B: Accelerator Composition B was ^Sika® Booster AC-30, a water-based paste available from Sika Schweiz AG containing 15-30% by weight of water. The accelerated adhesive KB1 was obtained by mixing the adhesive K and the accelerator composition B in a volume ratio of 10: 1 (K: B) on a laboratory machine with a gear meter (Static mixer Sulzer MS 13-18G). This resulted in an accelerated adhesive KB1 containing about 10% by volume of accelerator composition B. The adhesive K was heated to a temperature of 60 ° C. during the application. The extrusion speed when applying the adhesive KB1 was 5 cm ³ / s. The open time of KB1 was 1 min.

The optional accelerated adhesive KB2 was obtained by mixing the adhesive K and the accelerator composition B in a volume ratio of 50: 1 (K: B) on a laboratory unit with a gear metering device (static mixer Sulzer MS 3-8G). This resulted in an optionally accelerated adhesive KB2 containing just under 2% by volume of accelerator composition B. The adhesive K was heated to a temperature of 40 ° C. during the application. The extrusion speed when applying the adhesive KB2 was 5 cm ³ / s. The open time of KB2 was 5 min.

Results of the measurements

The results of the mechanical tests are given in Table 1.

The details of the given results, as well as related abbreviations and definitions are described above.

Table 1 shows that the prefixing adhesive KB1 already after 5 min sufficient early strength is achieved in order to burden a bond without additional pre-fixing. The adhesive KB2 requires 30 min to reach the same early strength. The lower final tensile shear strength of the adhesive KB1 does not play a major role in the bonding since the final attachment is achieved by the KB2 adhesive, which makes up the greater part of the bond in the process according to the invention. With regard to the module, it can be seen that the pre-fixing adhesive KB1 surprisingly has a modulus slightly lower than the final adhesive KB2. This avoids the effect that the total mechanical stress after the final bonding is on the much less applied prefixing adhesive, as is conventional in the art. The stiffer, higher modulus adhesive portion of the bond is in fact inevitably mechanically more heavily loaded. The difference in the module between KB1 and KB2 is also surprisingly small for a pre-fixed gluing. It also shows that the prefixing adhesive KB1 enables a strong, elastic pre-fixing bond. Adhesion is not adversely affected by the process according to the invention since both adhesives KB1 and KB2 show excellent adhesion behavior at all times.

Table 1: Results of the measurements.

Claims

Method for prefixing and bonding two parts T1 and T2, comprising the steps:

a) providing a one-component, moisture-curing adhesive K and an accelerator composition B, which contains between 10 and 80 wt .-% water, based on the accelerator composition B;

wherein steps b) and c) are performed in any order and the application amount of the accelerated adhesive KB1 to the part T1 is less than the application amount of the optional accelerated adhesive KB2 to the first part T1;

d) Joining the second part T2 on the splice, so that a composite joint T12 is formed, which connects the two parts T1 and T2 via the accelerated adhesive KB1 and the optional accelerated adhesive KB2. A method according to claim 1, characterized in that the adhesive K is a composition based on isocyanate group-containing polyurethane polymers or a composition based on silane-functional polymers.

A method according to claim 1 or 2, characterized in that the application of the accelerated adhesive KB1 and / or the optionally accelerated adhesive KB2 by means of a hand-guided applicator device, in particular a gun, is performed.

A method according to claim 1 or 2, characterized in that the application of the accelerated adhesive KB1 and / or the optionally accelerated adhesive KB2 is carried out by means of an automatic applicator device which has a movable application nozzle.

A method according to claim 3 or 4, characterized in that the applicator device comprises two separate chambers, wherein the adhesive K and the accelerator composition B are each located in one of the two chambers.

A method according to claim 5, characterized in that the applicator additionally comprises a mixing chamber into which both chambers open and which comprises a static or dynamic mixer.

Method according to one of the preceding claims, characterized in that the accelerated adhesive KB1 is not continuously, preferably punctiform, applied to the first part T1.

Method according to one of the preceding claims, characterized in that before the application of the adhesive KB1 an activator, Adhesive or primer is applied to the adherend surface of the part T1 and / or the part T2.

9. The method according to any one of the preceding claims, character- ized in that the accelerated adhesive KB1 and / or the optionally accelerated adhesive KB2 is heated before, during or after the application.

10. The method according to any one of the preceding claims, character- ized in that the accelerated adhesive KB1 between 7.5 and

Contains 12.5% by volume of accelerator composition B.

11. The method according to any one of the preceding claims, characterized in that the optionally accelerated adhesive KB2 contains between 0.5 and 3.5% by volume of the accelerator composition B.

12. The method according to any one of the preceding claims, characterized in that the accelerator composition B between 10 and 60 wt .-%, preferably between 15 and 40 wt .-% water.

13. The method according to any one of the preceding claims, characterized in that the accelerator composition B additionally contains at least one polymer and / or at least one acid and / or at least one catalyst for the curing of moisture-curing adhesives.

14. A product comprising at least two parts glued together, obtained by the method according to any one of claims 1 to 13. 15. Product according to claim 14, characterized in that it is an industrially manufactured product, in particular a vehicle.