WO2019081387A1

WO2019081387A1 - Dimensionally stable adhesive tapes

Info

Publication number: WO2019081387A1
Application number: PCT/EP2018/078814
Authority: WO
Inventors: Björn Zeysing; Tobias Winkler; Frank Virus
Original assignee: Tesa Se
Priority date: 2017-10-27
Filing date: 2018-10-19
Publication date: 2019-05-02

Abstract

The invention relates to an at least single-layer adhesive tape having an upper and a lower surface, each constituted by adhesive compounds. Said adhesive compounds are adhesive in the region of the upper and lower surfaces at room temperature and can be crosslinked at a temperature below 0°C. The adhesive tape is characterized by comprising at least one silicone-based layer and/or one layer based on silane-modified polymers.

Description

Dimensionally stable adhesive tapes

In particular, for use in the assembly area very thick, dimensionally stable adhesive tapes are required, but in which the adhesive used is not squeezed out of the bond line, especially when it comes to the bonding in the bonding to increased pressure on the bonding. At the same time, very high bond strengths are required in this area.

Thus, the state of the art includes dimensionally stable adhesive tapes with non-reactive pressure-sensitive adhesives. With such adhesive tapes, high layer thicknesses can be achieved. Curing is not required. These tapes have the property of being highly elastic; but only limited holding forces can be realized for this purpose.

Dimensionally stable adhesive tapes with reactive adhesives are also available. With these, however, only very limited layer thicknesses can be realized. To cure the adhesive systems used usually high temperatures are required. If pressure-sensitively adhesive adhesive systems are used, it is sometimes possible to provide immediate load bearing

Expandable, so-called "adhesive patches" are also known with these adhesive systems, but a high temperature is required for this purpose, which is not tolerated by all substrates Adhesive compounds achieve high strengths - with low elongation at break - but immediate load bearing is not possible with these systems.

Also worth mentioning are the liquid adhesives that cover a wide range of strength and elongation after cure at very low temperatures. With these adhesive systems in particular a tolerance compensation uneven substrate surfaces is possible; However, there is always a squeezing of the (low-viscosity) adhesive from the bonding joint, especially when pressure is applied to the adhesive bond before complete curing. Such squeezing of the adhesive is often undesirable. A load absorption before curing is not possible with these adhesive systems. The prior art does not provide satisfactory adhesive systems that combine the advantages of the aforementioned products, but reduce their disadvantages to a minimum. The object of the present invention is therefore to provide a bonding solution with high strength for joining two components, in which a high, constant adhesive thickness can be achieved. It is intended to allow a tolerance compensation between the joining partners and to ensure an immediate load bearing through the joint. For sensitive components, it is desirable to keep the processing temperature of the joining process low.

The problem could be solved by providing a suitable double-sided adhesive tape with sufficient elasticity.

In particular, it has been possible to provide thick adhesive tapes whose adhesive layer or adhesive layers have a sufficiently high viscosity in order to avoid production, adhesion and further handling of the adhesive bond and squeezing out of the adhesive joint, which nevertheless are sufficiently fluid.

These adhesive tapes are also suitable for tolerances in the joining area - eg. Unevenness of the substrate surfaces to be bonded - compensate.

Accordingly, a first aspect of the invention relates to an at least single-layered adhesive tape. The upper and lower surfaces of this adhesive tape are each formed by adhesives which are pressure-sensitive, at least in the area of the designated surfaces, in particular at room temperature (23 ° C.). In addition, the adhesives are curable at a temperature below 100 ° C; Hardening is usually a crosslinking reaction. The adhesive tape comprises at least one dimensionally stable layer, in particular a layer based on silicone and / or based on silane-modified polymers.

In principle, the adhesive tape according to the invention should have self-adhesive properties at the particular application temperature, that is to say the temperature at which it is applied to the substrate to be bonded, in order to bring about immediate adhesion to the substrate and to allow a direct load absorption at this application temperature. Particularly preferably, the adhesive tape according to the invention is tacky at room temperature, in particular in order to enable application on one or both substrate surfaces at room temperature, or around a composite, which may also be produced at relatively high temperatures store and transport the components to be bonded and the adhesive tape before curing at room temperature.

According to the invention adhesive films have pressure-sensitive adhesive properties. As "tacky" or "self-sticky" are referred to in the context of this document synonymous adhesives that allow even under relatively low pressure a permanent connection with the primer and can be replaced after use substantially residue-free from the primer again. For the purposes of the present invention, an adhesive pressure-sensitive adhesive tape has an adhesive strength in the uncured state of at least 0.5 N / cm, preferably 1 N / cm. The bond strength is determined here on steel analogous to ISO 29862: 2007 (Method 3) at 23 ° C. and 50% relative atmospheric humidity at a take-off speed of 300 mm / min and a take-off angle of 180 °. The reinforcing film used is an etched PET film with a thickness of 36 μm, as available from Coveme (Italy). The gluing of a 2 cm wide measuring strip is done by means of a 4 kg coiling machine at a temperature of 23 ° C. The tape is removed immediately after application. The measured value (in N / cm) was the average of three individual measurements.

Pressure-sensitive adhesives are permanently tacky at room temperature and therefore have a sufficiently low viscosity and high tack, so that they wet the surface of the respective adhesive base even at low pressure. The adhesiveness of the adhesives is based on their adhesive properties and the removability on their cohesive properties.

In principle, the adhesive tape according to the invention has an inner, dimensionally stable layer region (I) (hereinafter also referred to simply as "inner layer region") and two outer, pressure-sensitively adhesive, crosslinkable layer regions (A1, A2) (hereinafter also referred to simply as "outer layer regions"). on, compare the schematic structure in the figures Fig. 1a to Fig. 3.

These layer regions (I, A1 and A2) can be regions of a single adhesive layer S (FIGS. 1a and 1b) or of two layers S1, S2 (FIGS. 2a and 2b) or more layers (in particular three layers S1, S2, S3, see Fig. 3) are formed; see also below.

If two or three of the layer regions (I and A1, or I and A2, or I and A1 and A2) are regions of a single adhesive layer (S), this adhesive layer can in particular be formed homogeneously overall - the corresponding layer regions (I and A1, or I and A2, or I and A1 and A2) are then not distinguishable. The corresponding layer is then as a whole both dimensionally stable as well as tacky and crosslinkable. Fig. 1 a shows this embodiment.

Conversely, according to the invention, it is also conceivable that a single layer S - for example by means of appropriate surface treatments - does not have homogeneous properties over the entire layer thickness, cf. FIG. 1 b. The dot-dash lines in this diagram schematically separate the areas A1, I and A2 from each other. In this case, the "property change" between the layer areas does not need to be sharp, as the dot-dash line representation suggests, but the transition of the layer areas A1 into I and / or A2 in I can also take place, for example, continuously or otherwise "out of focus".

Not shown separately graphically, but nevertheless encompassed by the invention is a single-layer structure in which, for example, the layer regions I and A2 are homogeneous to one another, but the layer region A1 does not have completely identical properties for this, again assuming that the transition from A1 to I. then more or less sharp, continuous or otherwise designed. According to the invention, one or both of the outer layer regions A1 and / or A2 can also be individual adhesive layers which are not identical to the dimensionally stable layer I and have the properties defined for this layer (s) (compare FIGS. 2a, 2b and 3). The region (S1, S2, S3) designated by a curly bracket in each case designates a layer, which in turn can represent a single layer region, but can also comprise a plurality of (in particular two) layer regions. The solid lines between two layer areas each symbolize a transition between two separate layers. For the layer area transitions within a layer (dot-dash lines), the statements already made for FIGS. 1a and 1b apply accordingly. The inner layer region I can moreover be formed by more than one (two, three or more) identical or different dimensionally stable layers (not shown graphically). Bonding layers, such as additional (thin) adhesive layers, anchoring layers or the like, may optionally be provided between such dimensionally stable layers. The at least one dimensionally stable layer of the present invention is, in a preferred procedure, a polymer layer which may be chemically crosslinked. Thus, in principle, chemically fully crosslinked polymer layers can be used, but in particular preferably a chemically partially crosslinked polymer layer, ie a polymer layer in which bridge bonds are formed between at least part of the macromolecules in such a way that a network results but still sufficient functional groups for further crosslinking has.

In a preferred manner, when the outer layer regions A1, A2 are hardened, not only these outer layer regions, but also the inner layer region I, which is not or partially crosslinked, are essentially completely crosslinked or completely cured.

The state of affairs of an inner layer region I, advantageously at least initially partially crosslinked, in conjunction with curable adhesives (ie reactive adhesive systems) in the outer layer regions A1 and A2 can be realized, for example, by one of the following measures:

1. Especially with single-layer adhesive tapes: The reactive adhesive system is present over the entire tape width. This reactive adhesive system is first cross-linked and the cross-linking reaction stopped at a time when only partial cross-linking has taken place. The initiation of the curing (in particular after the application of the adhesive tape, ie the production of the final adhesive bond) takes place by full crosslinking of the reactive adhesive system.

2. Advantageously feasible for all illustrated adhesive tapes:

Two reactive systems are used, including, for example

a) a reactive resin and two hardeners;

b) two reactive resins and one hardener;

c) two reactive resins and one curing agent each, which reacts with one of the reactive resins.

One of the reactive systems (may be an adhesive, but need not necessarily) is at least in the inner region I of the adhesive tape, but may also be present in the outer regions A1 and / or A2. With this reactive system, first of all, a complete networking is carried out, at least partially, optionally. A second reactive system, which is an adhesive system, is present at least in the outer layer regions A1 and A2. By initiating the curing (in particular after the application of the adhesive tape, ie the production of the final adhesive bond) in the outer layer regions is carried out by fully crosslinking of the second reactive Adhesive system. If the first reactive system is only partially crosslinked at this point in time, it is advantageously fully crosslinked simultaneously with the curing reaction of the second reactive adhesive system.

For all illustrated adhesive tapes advantageously feasible:

A similar implementation to the above embodiment 2. but with the modification that the first reactive system is obligatory also an adhesive system comprising at least the inner layer region I and one of the outer layer regions A1, while the second reactive adhesive system only in the other outer layer regions A2 is present. The hardening process takes place as shown in 2. This variant offers the advantage that the bonding to the two substrates can be optimized by different adhesive systems.

For all illustrated adhesive tapes advantageously feasible:

A similar implementation to the above embodiment variant 2, but also with different reactive adhesive systems in the two outer regions A1 and A2 in addition to the reactive system which is present at least in the inner layer region I (ie a total of three reactive systems).

Especially for multi-layer adhesive tapes feasible:

Use of a fully crosslinked inner layer and two (identical or different) adhesive layers of reactive adhesive systems as outer layers. By initiating the curing (in particular after the application of the adhesive tape, ie the production of the final adhesive bond) in the outer layers, the crosslinking of these layers and thus the achievement of the ultimate bond strengths takes place.

In this variant, special attention should be paid to a good anchoring of the outer layers on the inner layer - possibly with special measures, such as contact surface activation or the like.

Especially for multi-layer adhesive tapes feasible:

Use of an only partially crosslinked inner layer and two (identical or different) adhesive layers of reactive adhesive systems as outer layers. By initiating the curing (in particular after the application of the adhesive tape, ie the production of the final adhesive bond) in the outer layers, the crosslinking of these layers and thus the achievement of the ultimate bond strengths takes place. Advantageously, the inner layer is fully crosslinked simultaneously with the curing reaction of the reactive adhesive system (s) in the outer layers. By appropriate, still active reactive groups of the inner layer, which - especially in the curing reaction - can react with the reactive adhesive systems of the outer layers, the anchoring of the outer layers can be optimized on the inner layer. By using a pressure-sensitive adhesive tape, which is initially adhesive on both sides, it can immediately absorb loads after first bonding in the glue joint. By subsequent - especially at room temperature - curing or crosslinking reaction at least the outer layer areas a strength is built up, which is well above all achievable by PSAs values.

In particular, curing or crosslinking is carried out after application of the adhesive tape, that is to say in particular after joining the composite of two substrates to be bonded together and the adhesive tape arranged therebetween, whereby a higher strength is developed after the curing reaction than before curing. As a quantitative criterion for the state of "higher strength", the tensile test is carried out with corresponding adhesive composition samples, whereby two test specimens of the dimensions 25.4 mm × 101, 6 mm × 1.0 mm with a bond area of 25.4 mm × 12, The bond is then cured under the conditions necessary for crosslinking the adhesive The strength of the bond is measured by a tensile test according to ISO 4587. According to the invention, the strength after the curing reaction is higher than before.

In a particularly preferred manner, the adhesives are already curable at temperatures of less than 50 ° C, more preferably at room temperature (23 ° C).

The initiation or activation of the curing reaction can be advantageously activated by radiation, such as UV radiation and / or visible light. In principle, all other types of radiation, such as electron radiation, plasma, corona, laser radiation and the like, can also be used here.

In an equally advantageous procedure, moisture-curing reactive systems, preferably adhesive systems, can be used, the curing thus being effected by water. In a further embodiment of the invention, the curing reaction is effected by the fact that the two reactants of the reactive system are present in two different adhesive layers (two-component system), which are first brought into contact during the bonding step that the curing reaction is triggered by bringing the reactants together. See also the following remarks in this document.

Preferably, in such a cure, the outer layer areas are substantially fully crosslinked or fully cured.

As already explained, in a further preferred manner, not only the outer layer regions A1 and A2 but also the inner layer region I, which is not or partially crosslinked, are substantially fully crosslinked or completely cured in such a curing. In a preferred manner, therefore, the - especially partially crosslinked - dimensionally stable layer is chosen so that takes place at temperatures below 100 ° C, preferably below 50 ° C, preferably at room temperature crosslinking on the still available functional groups.

A preferred type of crosslinking takes place by means of moisture (H2O). In order to ensure a sufficient storage stability of the adhesive before use, the adhesive tape is sealed in moisture exclusion in polymer film. Before application, the adhesive tape is removed from the polymer film. The crosslinking reaction starts so slowly by contact with the humidity that a joining process after opening the polymer film for a few hours is possible.

In a further preferred embodiment, the reactive adhesive is activated via UV radiation. In this case, the adhesive tape is stored in the absence of UV radiation, for example, welded in UV-impermeable film. For application, the adhesive tape is removed from the UV-impermeable film. The weak intensity of UV radiation in normal sunlight allows a processing time of a few minutes. The crosslinking is performed by a UV source of suitable wavelength and intensity.

The adhesive tape of the invention may be formed in one or more layers.

If it is of a single-layered construction, then the adhesives on the lower and on the upper surface of the adhesive tape are part of the dimensionally stable layer-in particular the layer based on silicone or based on silane-modified polymers; Thus, this dimensionally stable layer is then pressure-sensitive at its surfaces and curable according to the invention. In particular, this is realized by the fact that the dimensionally stable layer consists entirely of a pressure sensitive, curable material. Single-layer adhesive tapes of the invention consist in a preferred procedure of highly viscous, in particular at least partially crosslinked polymer, which still has sufficient reactive groups to allow binding to the substrate surfaces after curing.

Particularly advantageously, the entire layer should have a sufficiently high dimensional stability even before curing in order to prevent squeezing of the adhesive during production and storage.

"Sufficiently dimensionally stable" is to be understood in the first instance as meaning that a 6 mm thick pattern of an adhesive layer (for example a circular sample with a diameter of 1 cm) does not flow in a period of at least 24 h without external load and at +23 ° C, in particular in such a way that its contact surface with a planar substrate (for example a glass plate) does not increase by more than a maximum of 5%, preferably not more than 1%.

Closer consideration should also apply to "sufficiently dimensionally stable" that the change in the contact surface between the adhesive (as defined above tape sample - 6 mm thickness, circular blank, diameter 1 cm) and a planar substrate, such as a glass plate, after 24 h at uniform uniform loading of the adhesive tape sample by a 1 kg weight is not more than 200%, particularly preferably not more than 50%.

As adhesives from which the silicone-based layer or based on silane-modified polymers may be formed, there may be mentioned in particular:

1.) One or more moisture-curing silicones, as e.g. be used in conventional structural silicone adhesives and sealants (crosslinking reaction based on the silicone condensation). Advantageously, one, several (in any combination) or all of the following measures can be implemented to increase the cohesion and a

To prevent squeezing of the mass:

a. partial networking

b. Modification with rheology additives.

These are usually particulate fillers (such as, for example, phyllosilicates, polysilicic acid, polymer particles (for example polyamides), etc.), in particular those fillers which form interactions with the silicone macromolecules, which lead to an increase in viscosity or to a cohesion increase

c. Blending with - especially non-reactive - film formers

Film formers are thermoplastics that are compatible with the adhesive (miscible) and thus in mixture to a compared to the pure adhesive increased viscosity to lead. The film formers are characterized in that they generally form a full-surface film in which the adhesive is present-in particular homogeneously distributed-whereby the film formers do not substantially reduce the crosslinking potential of the adhesive.

d. Addition of "reactive film formers"

Reactive film-forming agents are polymers having functional groups which build up a polymeric skeleton and react with reactive components of the adhesive during the production process of the adhesive, so that a common (chemically combined) network is formed. Reactive film formers are thus those polymers which have functional groups functionalized with functional groups

Adhesive can react. The reaction of these "reactive film formers" with the reactive groups of the adhesive leads to an increase in the viscosity and a prevention of squeezing out of the adhesives.After reaction of the reactive film former with the adhesive, sufficient reactive groups are left to significantly increase the cohesion in the frame to lead to the curing reaction.

e. Incorporation of the adhesive into an open-celled foam, a perforated support layer, or an "open" textile (open cell foam, perforated support layer, and "open" textile hereinafter collectively referred to as "open support") to increase dimensional stability, one of the following approaches which can also be performed in combination with each other, advantageous:

i. Adhesive is flowable at high temperature, then introduced into the open carrier and on cooling, the viscosity increases so that the adhesive does not squeeze out again (see the document DE 10 2015 217 840 A for this principle)

ii. Support impregnation of the open backing with adhesive by using pressure

2.) One or more UV-crosslinkable silicones, crosslinking on the basis of addition reactions

3.) One or more with UV radiation or by light irradiation (especially blue light) cationically crosslinking silicones

4.) One or more UV-crosslinkable silicones, free-radically crosslinking, in particular by means of acrylate-functionalized silicones

5.) A mixture of vinyl- and mercapto-functionalized silicones cured by UV radiation 6.) One or more moisture-crosslinking modified silanes (MS polymer / silane terminated polymers) as available as MS polymer in various compositions. In a modification of the invention (alternative embodiments), the dimensionally stable layer is formed by another cohesive adhesive whose surfaces can realize high bond strengths by hardening. The basis for such an adhesive may be, for example:

7.) One or more moisture-curing isocyanates

8.) One or more thermally activatable moisture-curing isocyanates

9.) One or more UV-crosslinkable epoxides

10.) One or more radiation-crosslinking acrylates, in particular with UV radiation or by light irradiation (in particular blue light) to be brought to polymerization compositions containing acrylate monomers.

1 1.) One or more plasma-activatable acrylates

It is also possible to use mixtures (blends) of the abovementioned polymer or adhesive compositions, the composition comprising two or more of the abovementioned representatives, including other polymer and / or adhesive mass systems not mentioned, in principle - apart from those given chemically or technically - no limits are set. The adhesives may be additized with additives, based on the familiar to the expert knowledge of adhesive additives, in particular with regard to the achievement of certain properties of the adhesives is here based. A second embodiment of the adhesive tape according to the invention consists of a two-layered structure with the dimensionally stable layer - in particular layer of silicone-based or based on silane-modified polymers (in the sense of a common layer comprising the inner layer region and one of the outer layer regions A1) and a further, pressure sensitive, curable Adhesive layer (in the sense of the other outer layer region A2). The further adhesive-tacky, curable adhesive layer (in the sense of the other outer layer region A2) may likewise be an adhesive based on silicone or based on silane-modified polymers, but in principle all other adhesive, curable adhesive systems can be used here. In particular, the adhesive tape can be made specific by selecting the adhesive used there Bonding requirements by the corresponding substrate to be bonded to be adapted.

In particular, the dimensionally stable layer can be realized as defined for the single-layer adhesive tape; on a silicone basis, based on silane-modified polymers or in the alternative embodiment shown there.

Suitable adhesives for the further adhesive-tacky, curable adhesive layer are in principle all curable adhesive systems, in particular also those adhesive systems as already mentioned for the dimensionally stable layer. By way of example and with advantage, the following reactive adhesive mass systems may be mentioned here:

1.) One or more moisture-curing silicones - as e.g. used in common structural silicone adhesives and sealants (base silicone condensation); where also one, several (in any combination) or all of the following states can be realized:

a. unmodified

b. Partially networked

c. Modified with rheology additives

d. Mixed with non-reactive film former

e. Additiviert with "reactive film formers"

f. in an open-celled foam or a perforated carrier or an "open" textile introduced

2.) One or more silicones activatable via UV radiation (silicone addition)

4.) One or more UV-crosslinkable silicones, radically crosslinking

5.) A mixture of vinyl- and mercapto-functionalized silicone cured by UV radiation

6.) One or more moisture-crosslinking modified silanes (MS polymers / silanes

Terminated Polymers)

7.) One or more moisture-curing isocyanates

8.) One or more thermally activatable moisture-curing isocyanates

9.) One or more UV-crosslinkable epoxides

10.) One or more radiation-curing acrylates

1 1.) One or more radiation-curing acrylates, in particular with UV radiation or by light irradiation (in particular blue light) to be brought to polymerization compositions containing acrylate monomers. 12.) One or more plasma-activatable acrylates

It is also possible to use mixtures (blends) of the abovementioned adhesives, with the composition of two or more of the abovementioned representatives, including other adhesive mass systems not mentioned, generally having no limits, except those given in chemical or technical terms.

The adhesives may be additized with additives, based on the familiar to the expert knowledge of adhesive additives, in particular with regard to the achievement of certain properties of the adhesives is here based.

A further embodiment of the invention relates to an at least three-layered structure, and in particular a precisely three-layered structure, comprising the at least one dimensionally stable layer, in particular silicon-based or silane-modified polymer layers (in the sense of inner layer region I) and two further external layers adhesive-tacky, curable adhesive layers (in the sense of the outer layer regions A1 and A2).

Such product structures provide further advantages. First, the dimensionally stable layer

- In particular layer based on silicone or based on silane-modified polymers

- Be not even pressure-sensitive and / or curable, since the bonding to the substrates can be effected by the outer adhesive layers. Thus, the portfolio of polymer systems that can be used for this purpose has been considerably expanded, namely non-adhesives. Of course, the dimensionally stable layer, in particular silicone-based layer or based on silane-modified polymers, may themselves be tack-tacky and / or curable.

The adhesives for the outer layers (in the sense of the outer layer regions A1 and A2) can be selected independently of one another. The outer layers may be chemically identical or different.

For both layers, it is possible, for example, to select (identical or different) silicone-based or silane-modified polymers. However, it is also possible for an outer layer to use a further silicone-based adhesive or silane-modified polymers and for the other outer layer an adhesive which is not based on silicone or silane-modified polymers. Or, for both outer layers, it is possible to choose those adhesives which are not based on silicone or silane-modified polymers, it being possible for the outer layers to be chemically identical or different. In principle, here are all can be used further adhesive, curable adhesive systems. A particular advantage is that both surfaces of the adhesive tape can be adapted to the requirements of each substrate to be bonded. The adhesive of one or both of the outer layers may moreover be identical to or different from the composition of which the dimensionally stable layer is made, in particular based on silicone or based on silane-modified polymers.

For the silicone-based layer or based on silane-modified polymers, in particular the adhesive mass systems can be used, as they are already mentioned for the single-layer and the two-layer variant - and again in the form of alternatives -, where here - as already stated, the freedom also has to select those systems which themselves are not tacky and / or curable.

Specifically, in particular the adhesives can be used for the outer adhesive layers, as they have already been mentioned above for the two-layer adhesive tape.

The dimensionally stable layer may advantageously be an elastic or viscoelastic layer. In particular, it has a high strength. In a preferred embodiment of the invention, the at least one layer based on silicone or based on silane-modified polymers has viscoelastic properties. The viscosity of the core layer is sufficiently high that squeezing when winding on a roll and subsequent storage and transport is avoided. In particular, however, it is still sufficiently low that the adhesive tape is capable of allowing a tolerance compensation when joining two components. The construction according to the invention makes it possible to realize very thick adhesive tapes which fulfill the requirements of the object of the invention. In particular, adhesive tapes with overall thicknesses of at least 1 mm, but also at least 1, 5 mm, at least 2 mm, at least 3 mm, at least 4 mm, at least 5 mm and even at least 6 mm can be realized. The thickness values mentioned are mentioned here by way of example; so adhesive tapes can be realized considerably higher overall thicknesses.

With the illustrated invention, thick, dimensionally stable adhesive tapes can be provided whose viscosity is sufficiently high to prevent squeezing of the mass, but which are sufficiently flowable to compensate for tolerances in the joining region (up to xxx). The adhesives used are tacky and can immediately loads take up. By means of a crosslinking reaction, which takes place particularly advantageously at room temperature, strengths are established which are significantly above all values achievable by pressure-sensitive adhesives. In a particularly preferred manner, the sum of the thicknesses of all dimensionally stable layers - in particular of all layers based on silicone or based on silane-modified polymers - make up at least 80% of the total thickness of the adhesive tape, preferably at least 90%. For the single-layered embodiment of the adhesive tape according to the invention, this inevitably results for the multilayer adhesive tapes, which exclusively have layers of silicone-based adhesives and / or those based on silane-modified polymers, likewise.

The dimensionally stable layer, in particular the at least one layer based on silicone or based on silane-modified polymers - after curing or crosslinking, a maximum tensile strength of at least 500 kPa, measured according to ISO 527-3.

It is preferable for the entire adhesive tape to have a maximum tensile strength after curing of at least 500 kPa, measured according to ISO 527-3.

The adhesive tape of the invention is further distinguished by the fact that it has a strength of at least 250 kPa after curing in the front tensile test between a glass and a metal substrate at a measurement in the entire temperature range between -40 ° C and + 90 ° C. (determined ASTM D 897-8).

Another aspect of the invention relates to a composite of two interconnected by means of an adhesive system substrates.

In this case, as an adhesive system preferably an inventive at least single-layer, double-sided adhesive tape is used, as described in more detail in the context of this document.

The adhesive tape can be used as such as previously described; however, in a modification, the adhesive tape may also have been produced only after the bonding process. This variant of the invention is described in particular in that the adhesive system a sequence of at least two layers bonded together, of which at least one of the layers is a silicone-based and / or based on silane-modified polymers. For this layer sequence in the finished composite, in principle, the full extent already shown for the inventive adhesive tape applies.

Accordingly, in the aforementioned composites, the total thickness of the adhesive system is preferably at least 1 mm, more preferably at least 1.5 mm, more preferably at least 2 mm, even more preferably at least 3 mm, even more preferably at least 4 mm, even more preferably at least 5 mm. even more preferably at least 6 mm.

The aforementioned composites can in particular be produced in such a way that one of the substrates to be joined is provided with the adhesive system, ie in particular by the adhesive system - in particular the adhesive tape of the invention - being bonded to one of its pressure-sensitive adhesive surfaces on this substrate. The second, sticky, still exposed surface is then bonded to the second of the substrates to be joined or the second of the substrates to be bonded on this.

The adhesive systems according to the invention are curable, in particular at least on their surfaces, as has already been described for the adhesive tape of the invention. By a subsequent curing process, the desired adhesive forces are then achieved.

For such composites according to the invention, in which the adhesive system comprises a sequence of at least two layers bonded together, wherein at least one of the layers is based on silicone and / or based on silane-modified polymers, a modification of the method for their production can also be carried out. In this case, one of the substrates to be joined is equipped with at least one of the layers to be bonded together, or with a composite already several interconnected layers. The second of the substrates to be joined is provided with at least one other of the layers to be bonded together, or also with an already existing layer composite.

The joining of the substrates to be joined is then carried out by bringing together the free surfaces of the adhesive layers or adhesive layer composites to be bonded together. In this case, the adhesive tapes can either (preferably) be fixed on different components and - if appropriate, after so-facilitated interim storage - be added to each other. In a modification of this method, an adhesive tape can first be fixed on a component, wherein the second is then added to the first. Only then is the second component bonded to the free surface of the second adhesive tape.

Of course, according to the above methods, more than two adhesive tapes can be used for the production of the overall adhesive system.

If adhesive tape layers are first applied to the substrate or component surfaces and then the exposed adhesive surface surfaces are glued together, this results in the advantage that this process allows significantly better wetting of the rigid substrate or component surfaces than an application of a rigid component Adhesive tape with the second rigid component would allow this.

An advantage of the variant of the invention in which the adhesive system in full thickness is produced quasi only during the bonding (two-component or multi-component adhesive tape system, at least comprising the respective film or adhesive tape-shaped components A and B, hereinafter referred to as film A and Film B), it is possible to offer less thick adhesive tapes, which are laminated together during the application process. For example, it is possible to use thinner variants of the adhesive tapes according to the invention described above as one-, two-, or multi-layer finishes. The final thickness of the adhesive system in the adhesive joint (or the gap between the substrates to be bonded) then results from the addition of the thicknesses of the individual adhesive tapes used.

Such a procedure is suitable, for example, to reduce the requirement for the (high) viscosity) of the adhesive tape in order to prevent squeezing of the adhesive. In addition, a two-component or multi-component adhesive tape system allows for the spatial separation of reactive components that are stable in storage in one of the adhesive tapes alone and are reacted in a short time when contacted with the other component. Special inventive two-component and multi-component adhesive tape systems for thick reactive adhesive tapes include beispielswiese

1) Vinyl-functionalized (preferably (meth) acrylate-functionalized) silicone in film A and highly reactive peroxide component in film B.

2) Vinyl functionalized silicone and initiator (e.g., Fe phthalocyanine) in Film A and peroxide component (e.g., cumene hydroperoxide) in Film B

3) Mercapto-functionalized silicone in film A and vinyl-functionalized silicone in film B. The crosslinking takes place here in particular after contact with UV radiation. The adhesive tapes according to the invention and the adhesive methods according to the invention can be used particularly advantageously in assembly, for example in the bonding of façade elements.

Another advantageous field of application is found in the automotive sector, in particular in the bonding of components and components with each other or with the body. In particular, a good suitability of the adhesive tapes according to the invention for the bonding of glass - such as glass panes in the holder or in frame - or for the bonding of components or components is given to glass. Such components to be glued to glass may be, for example, the base of mirror mounts, mounts for sensors - such as -, compression springs - for example for door or tailgate openings - and the like.

A further advantageous use of the adhesive tapes according to the invention is, for example, in the fixation of glass panes in facade elements ("structural glazing").

Claims

claims

1. At least single-layered adhesive tape having an upper and a lower surface, each formed by adhesives, wherein the adhesives in the region of the upper and lower surfaces are pressure-sensitive at room temperature and crosslinkable at a temperature below 100 ° C,

characterized in that the adhesive tape comprises at least one layer based on silicone and / or based on silane-modified polymers.

2. Adhesive tape according to claim 1, characterized in that

the at least one layer based on silicone or based on silane-modified polymers has elastic or viscoelastic properties.

3. Adhesive tape according to one of the preceding claims, characterized by a total thickness of at least 1 mm, preferably at least 1, 5 mm, more preferably at least 2 mm, even more preferably at least 3 mm, even more preferably at least 4 mm, even more preferably at least 5 mm, more preferably at least 6 mm.

4. Adhesive tape according to one of the preceding claims, characterized by a single-layered construction.

5. Adhesive tape according to one of claims 1 to 4, characterized by a two-layer structure, consisting of the layer of silicone-based or based on an MS polymer and a further, pressure-sensitive, curable adhesive layer.

6. Adhesive tape according to one of claims 1 to 4, characterized by an at least three-layer structure comprising the at least one layer based on silicone or based on silane-modified polymers and two other, external, pressure-sensitive, curable adhesive layers.

7. Adhesive tape according to claim 6, characterized by a three-layer structure.

8. Adhesive tape according to one of claims 5 to 7, characterized in that at least one of the further, pressure-sensitive, curable adhesive layers is likewise a layer based on silicone or based on silane-modified polymers.

9. The method according to claim 8, characterized in that

all other, pressure-sensitive, curable adhesive layers are likewise layers based on silicone and / or based on silane-modified polymers.

10. Adhesive tape according to one of claims 5 to 7, characterized in that

none of the further, pressure-sensitively adhesive, curable adhesive layers is a silicone-based layer or based on silane-modified polymers.

1 1. Adhesive tape according to one of the preceding claims, characterized in that

the sum of the thicknesses of all silicone-based layers or based on silane-modified polymers is at least 80% of the total thickness of the adhesive tape, preferably at least 90%.

12. Adhesive tape according to one of the preceding claims, characterized in that

the at least one layer based on silicone or based on silane-modified polymers after curing has a maximum tensile strength of at least 500 kPa, measured according to ISO 527-3.

13. Adhesive tape according to one of the preceding claims, characterized by

a maximum tensile strength of at least 500 kPa after curing, measured according to ISO 527-3.

14. Adhesive tape according to one of the preceding claims, characterized by a value of at least 250 kPa in measurements in Stirnzugversuch over the entire temperature range of - 40 to + 90 ° C.

15. Adhesive tape according to one of the preceding claims, characterized in that a uniform, full-surface load of a bonded to a planar surface 6 mm thick, circular tape sample (diameter 1 cm) by a weight of 1 kg for 24 h to increase the contact surface of the Adhesive tape sample to the substrate of a maximum of 200%, preferably a maximum of 50% leads.

16 composite of two interconnected by means of an adhesive system substrates, being used as the adhesive system, an at least single-layer, double-sided adhesive tape according to one of the preceding claims.

17. composite of two interconnected by means of an adhesive system substrates,

wherein the adhesive system is a sequence of at least two layers bonded together, of which at least one of the layers is based on silicone and / or based on silane-modified polymers.

18. Composite according to one of claims 16 or 17, characterized in that

the adhesive system has a total thickness of at least 1 mm, preferably at least 1.5 mm, more preferably at least 2 mm, even more preferably at least 3 mm, even more preferably at least 4 mm, even more preferably at least 5 mm, even more preferably at least 6 mm ,

19. A process for producing a composite according to claim 16 to 18, characterized in that

one of the substrates to be joined is equipped with the adhesive system,

and the substrates to be joined together are then adhesively bonded together by contacting the adhesive system with the second of the substrates to be bonded.

20. A process for producing a composite according to any one of claims 16 to 18, characterized in that

one of the substrates to be joined is provided with at least one adhesive tape according to one of claims 1 to 15,

the second of the substrates to be joined is likewise provided with at least one same or different adhesive tape according to one of Claims 1 to 15, and the substrates to be joined together are then joined together by bringing the two adhesive tapes together.

21. Method according to one of claims 19 or 20, characterized in that

the adhesive tapes are cured after bonding at a temperature of not more than 100 ° C, in particular at room temperature.

22. The method according to claim 21, characterized in that

curing is activated by UV radiation and / or visible light and / or moisture.

23. The method according to claim 21, characterized in that

the curing is effected by means of a two-component adhesive system.